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Sample records for policlosrodibenzofuranos pcdfs por

  1. PCBs, PCQs and PCDFs in tissues of Yusho and Yu-Cheng patients

    SciTech Connect

    Miyata, H.; Fukushima, S.; Kashimoto, T.; Kunita, N.

    1985-02-01

    All five samples of oil involved in the recent Yu-Cheng outbreak were heavily contaminated with PCBs, PCQs and PCDFs at levels, on the average, of 62, 20 and 0.14 ppm, respectively. The samples not only had roughly one-tenth of the contamination by PCBs, PCQs and PCDFs but also three to four times lower ratios of PCQs and PCDFs to PCBs than samples of oil involved in Yusho in Japan. PCBs, PCQs and PCDFs present were all composed of similar congeners to the ones found in the Yusho specimens, though some variation of the component ratios of PCBs and PCDFs were observed. On the other hand, five patients with Yusho who died 1 to 10 years following poisoning had markedly higher tissue levels of PCDFs and PCQs than did a worker occupationally exposed to PCBs. Taking great differences in the process of the healing and the tissue levels of PCBs, PCQs and PCDFs between the two poisoning cases into consideration, PCDFs and PCQs - especially the former - and not PCBs are deduced to be strongly associated with the development of Yusho.

  2. Removal efficiencies of PCDDs/PCDFs by air pollution control devices in municipal solid waste incinerators.

    PubMed

    Kim, S C; Jeon, S H; Jung, I R; Kim, K H; Kwon, M H; Kim, J H; Yi, J H; Kim, S J; You, J C; Jung, D H

    2001-01-01

    Removal efficiencies of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) by air pollution control devices (APCDs) in the commercial-scale municipal solid waste (MSW) incinerators with a capacity of above 200 ton/day were evaluated. The removal efficiencies of PCDDs/PCDFs were up to 95% when the activated carbon (AC) was injected in front of electrostatic precipitator (EP). Spray dryer absorber/bag filter (SDA/BF) had high removal efficiency (99%)) of PCDDs/PCDFs when a mixture of lime and AC was sprayed into the SDA. When the AC was not added in scrubbing solution, the whole congeners of PCDDs/PCDFs were enriched in the wet scrubber (WS) with negative removal efficiencies of -25% to -5731%. Discharge of PCDDs/PCDFs was decreased with increasing the proportions of AC added in scrubbing solution. Selective catalytic reduction (SCR) system had the removal efficiencies of up to 93% during the test operation.

  3. Behavior of PCDDs/PCDFs in remediation of PCBs-contaminated sediments by thermal desorption.

    PubMed

    Sato, Takeshi; Todoroki, Tomohiro; Shimoda, Kimiaki; Terada, Akihiko; Hosomi, Masaaki

    2010-06-01

    Thermal desorption is an effective method for removing volatile and semivolatile organic matter in contaminated solid remediation. Formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in many polychlorinated biphenyls (PCBs) destruction processes has been reported, but the removal pathways are poorly understood. We therefore investigated the behaviors of PCBs and PCDDs/PCDFs in thermal desorption of PCBs-contaminated sediment and predicted the reaction pathways. Four thermal desorption experiments using PCB-contaminated sediments containing different doses of PCBs were carried out. In all the experiments, decomposition of 48-70% of PCBs was achieved, resulting in formation of PCDFs. Despite the PCBs decomposition levels, toxic equivalencies (TEQs) in the treated and volatilized samples were 2.8-6.3 times and 8.0-10.5 times as high as the TEQs in the initial samples, respectively, indicating increased toxicity after treatment. Further analysis revealed that PCDFs with higher numbers of chlorine atoms are likely to remain in the sediments than those of volatilized PCDFs; this is supported by the positive correlation between the vapor pressures of PCDFs and the ratios of volatilized PCDFs. PMID:20382407

  4. Enrichment of PCDDs/PCDFs in peripheral utilities of the municipal solid waste incineration facility.

    PubMed

    Kim, Sam-Cwan; Song, Geum-Ju; Seok, Kwang-Seol; Ko, Yun-Hwa; Hunsinger, Hans

    2013-05-01

    This study was performed to suggest the improvements through measuring the amounts of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), re-synthesized in peripheral utilities (PUs) of a commercial-scale municipal solid waste incineration facility (MSWIF) where a few research results existed. The PUs examined in this study consisted of air pre-heaters (APHs) and gas/gas re-heater (GGRH) and kerosene-fired duct burner for selective catalytic reduction (SCR) process. PCDDs/PCDFs in flue gas were simultaneously measured at the inlet and outlet of PUs. Flue gas was cooled down from 380 °C to 249 °C by exchanging the heat with fresh air in APHs, and then heated up to 383 °C by GGRH and duct burner from 164 °C at the outlet of bag filter. The results showed that PCDDs/PCDFs were 3-4 times higher within this temperature range of PUs. In comparison of PCDDs/PCDFs concentrations at the inlet with those at the outlet of PUs, particulate-phase PCDDs/PCDFs were about 9.5-10 times enriched while gaseous-phase ones were decreased by about 33-41%. The PCDDs/PCDFs re-synthesized in the PUs, where PCDDs were relatively higher than PCDFs, showed somewhat different patterns compared to those formed at incinerators and emitted at stack. Through the investigations for PUs, we conclude that the PUs used in MSWIFs was a potential source for de novo synthesis of PCDDs/PCDFs.

  5. Nondestructive scat sampling in assessment of mink (Mustela vison) exposed to polychlorinated dibenzofurans (PCDFs).

    PubMed

    Zwiernik, Matthew J; Moore, Jeremy N; Khim, Jong Seong; Williams, Lisa L; Kay, Denise P; Bursian, Steve; Aylward, Lesa L; Giesy, John P

    2008-10-01

    The mink (Mustela vison) is often utilized as a sentinel species for ecological assessments at sites where contaminants of concern include dioxins and dioxin-like compounds. Utilizing mink scat as a nondestructive tool to determine internal exposure to dioxin-like compounds may allow for rapid, accurate estimates of exposure without the need to capture mink or their prey. To determine the relationships between concentrations of polychlorinated dibenzofurans (PCDFs) in tissues (liver and adipose) and those in scat, mink were fed PCDFs in scat during a controlled laboratory study for 180 days. Mink were fed a control diet, diets with three doses of 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PeCDF) or 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF), and a diet with an environmentally relevant mixture of the two congeners. Concentrations of PCDFs in liver and adipose were measured after 0, 90, and 180 days of exposure. Concentrations of the two PCDF congeners in mink scat were determined after 2, 23, 45, 90, and 180 days of exposure. Concentrations of both PCDF congeners in scat were significantly correlated with those in liver and adipose tissue (r(2) = 0.94-0.97, p < 0.01). This indicates that measurements of concentrations of both PCDFs in scat can be used to predict concentrations of PCDFs in liver and adipose. Assimilation and elimination characteristics of 2,3,4,7,8-PeCDF or 2,3,7,8,-TCDF and a mixture of the two congeners by mink could be predicted from concentrations of these congeners in scat. Overall, concentrations of PCDFs in mink scat can be used as a rapid and inexpensive nondestructive method to predict concentrations of PCDFs in mink when certain assumptions are met. PMID:18227958

  6. The biomagnification of PCBs, PCDDs, PCDFs in a simplified laboratory food chain

    SciTech Connect

    Taplin, B.; Pruell, R.; McGovern, D.; McKinney, R.

    1995-12-31

    The trophic transfer and biomagnification potential of polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs), were investigated in a simplified marine benthic food chain. Polychaetes, Nereis virens were exposed to contaminated sediment and fed to juvenile lobsters, Homarus americanus exposed to the same sediment for 112 days. Time series uptake and depuration measurements were made for lobster muscle and hepatopancreas. A nonlinear model (BIOFAC) was used to calculate uptake and depuration rate constants, bioaccumulation factors, and steady state concentrations for PCBs, PCDDs, and PCDFs. Biomagnification factors (BMFs), on a lipid weight basis, were calculated for both tissues. Lobsters accumulated PCDDs, PCDFs, and PCBs from contaminated sediment and food (polychaetes). Of the two tissues, lobster hepatopancreas, showed the highest concentrations for all compounds analyzed. Of the PCDDs and PCDFs studied, only 2,3,7,8-tetrachlorodibenzodioxin, 2,3,7,8-tetrachlorodibenzofuran, 2,3,4,7,8-pentachlorodibenzofuran, and 1,2,3,4,7,8-hexachlorodibenzofuran were detected in lobster muscle and hepatopancreas tissues. Of the PCB congeners studied, 2,2{prime},4,4{prime},5,5{prime} hexachlorobiphenyl reached the highest concentration in lobster muscle and hepatopancreas. Lobsters also accumulated non-ortho substituted PCBs in both tissues.

  7. TOXIC EQUIVALENCY FACTORS (TEFS) FOR PCBS, PCDDS, PCDFS FOR HUMANS AND WILDLIFE

    EPA Science Inventory

    An expert meeting was organized by the World Health Organization (WHO) and held ih Stockholm on 15-18 June 1997. The objective of this meeting was to derive cohsensus toxic equivalency factors (TEFs) for polychlorinated didbenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dio...

  8. Congener specific biotransformation and bioaccumulation of PCDDs and PCDFs from fly ash in fish

    SciTech Connect

    Sijm, D.T.H.M.; Opperhuizen, A. . Research Inst. of Toxicology, Environmental Chemistry Group); Wever, H. . Dept. of Environmental and Toxicological Chemistry)

    1993-10-01

    Biotransformation may be responsible for the lack of bioaccumulation of a number of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Goldfish (Carassius auratus) that were exposed to PCDDs and PCDFs, and piperonylbutoxide (PBO) in water bioconcentrated significantly more congeners than goldfish exposed to PCDDs and PCDFs only. Monooxygenase activity, which is responsible for the oxidation of specific PCDD and PCDF congeners in untreated fish, was inhibited by fish treated with PBO. In the PBO-treated group and in the control group, congeners with all lateral positions substituted were found. Congeners that lack chlorine substitution on one or more of the lateral positions substituted were found. Congeners that lack chlorine substitution on one or more of the lateral (2,3,7,8) positions and congeners that have all lateral positions chlorinated were found only in PBO-treated fish. Congeners that have at least one free lateral position were therefore assumed to be biotransformed. There was no relationship between the octanol/water partition coefficient and biotransformed. There was no relationship between the octanol/water partition coefficient and biotransformation of the PCDDs and PCDFs. No limitation of uptake for higher chlorinated PCDD and PCDF congeners was found.

  9. COMPARING PCDDS, PCDFS, AND DIOXIN-LIKE PCBS IN FARM-RAISED AND WILD-CAUGHT CATFISH FROM SOUTHERN MISSISSIPPI

    EPA Science Inventory

    Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) [hereafter referred to as ¿dioxin-like compounds¿] are persistent environmental contaminants that have been found to be ubiquitous in environmental media and bio...

  10. Full-scale plant study on low temperature thermal dechlorination of PCDDs/PCDFs in fly ash.

    PubMed

    Ishida, M; Shiji, R; Nie, P; Nakamura, N; Sakai, S

    1998-01-01

    The low temperature thermal dechlorination process is an effective technology of dioxins decomposition in fly ash of municipal solid waste incinerators(MSWI). A full-scale dechlorination process was designed and constructed in Matsudo city, Japan. It was confirmed that PCDDs/PCDFs decomposition ratio was more than 99% with temperature of 350 degrees C and retention time of 1 hour, and thermal dechlorination moved on from PCDDs/PCDFs having more chlorine atoms to those of less chlorine atoms.

  11. The biomagnification of PCBs, PCDDs, and PCDFs in a simplified laboratory food chain

    SciTech Connect

    Taplin, B.; Pruell, R.; McGovern, D.; McKinney, R.

    1995-12-31

    Polychaetes Nereis virens were exposed to contaminated sediment and fed to juvenile lobsters, Homarus americanus exposed to the same sediment for 112 days. Time series uptake and deputation measurements were made for lobster muscle and hepatopancreas. A nonlinear model (BIOFAC) was used to calculate uptake and deputation rate constants, bioaccumulation factors, and steady state concentrations for PCBS, PCDDS, and PCDFS. Biomagnification factors (BMFs), on a lipid weight basis, were calculated for both tissues. Lobsters accumulated PCDDS, PCDFS, and PCBs from contaminated sediment and food (polychaetes). Of the two tissues, lobster hepatopancreas showed the highest concentrations for all compounds analyzed. Of the PCDDs and PCDFs studied, only 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD), 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF), 2,3,4,7,8-pentachlorodibenzofuran, and 1,2,3,4,7,8-hexachlorodibenzofuran were detected in lobster muscle and hepatopancreas tissues. Of the PCB congeners studied, 2,2{prime},4,4{prime},5,5{prime} hexachlorobiphenyl (UPAC No. 153) reached the highest concentration in lobster muscle and hepatopancreas. Lobsters also accumulated non-ortho substituted PCBs in both tissues. Biomagnification factors (BMFS) were calculated for lobster muscle and hepatopancreas on a lipid weight basis using steady-state concentrations. BMFs for lobster hepatopancreas were generally higher than those for muscle. Of the PCDDs and PCDFs studied, only 2,3,7,8-TCDD and 2,3,7,8-TCDF were biomagnified in lobster hepatopancreas and muscle compared with levels in the polychaetes. Selected PCB congeners were also biomagnified in both tissues. PCB congeners with log{sub 10} K{sub ow} values > 6.5 had higher BMFs for hepatopancreas tissue than compounds with lower K{sub ow`s}. No trend was evident regarding log{sub 10} K{sub ow} of PCBs and BMFs for lobster muscle.

  12. PCDDs (polychlorinated dibenzo-p-dioxins) and PCDFs (polychlorinated dibenzofurans) in humans

    SciTech Connect

    Swanson, S.E. ); Erickson, M.D. )

    1990-01-01

    Numerous instances of human exposure to polychlorinated dibenzo-p- dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) have been documented. Following the development of sufficiently specific and sensitive analytical methods during the past few years, many reports have appeared on PCDD and PCDF levels in human blood and adipose tissues. Studies have examined the PCDD and PCDF levels resulting from accidental and occupational exposures of various groups, including chemical plant workers, forestry and tannery workers, and Niet Nam veterans who had handled Agent Orange. The general background levels in the US, Federal Republic of Germany, Japan, and Sweden were also determined. The results of these studies indicate that a background level of PCDDs and PCDFs is present in the overall population. In some cases, individuals exposed to specific PCDDs or PCDFs exhibit higher levels than the general population. Isomer distribution patterns are relatively consistent and indicative of sources and metabolism. This paper reviews the available data on human PCDD and PCDF levels in exposed and general populations. 15 refs., 4 figs.

  13. PCBs, PCQs and PCDFs in blood of Yusho and Yu-Cheng patients

    SciTech Connect

    Kashimoto, T.; Miyata, H.; Fukushima, S.; Kunita, N.; Ohi, G.; Tung, T.

    1985-02-01

    Individual blood samples obtained from Yusho and Yu-Cheng patients who had been poisoned by ingesting contaminated cooking oils, from workers occupationally exposed to polychlorinated biphenyls (PCBs) and from unexposed individuals were analyzed for PCBs, polychlorinated quaterphenyls (PCQs) and polychlorinated dibenzofurans (PCDFs) by gas chromatography and mass spectrometry. PCBs were found in the blood of all samples. PCQs were detected in the blood of 54 or 56 living Yusho patients 11 years after the outbreak, and in all Yu-Cheng patients 6 months following poisoning. These facts indicate that the presence of PCQs in the blood was a good mark of past ingestion of the toxic oil. In the Yu-Cheng cases, PCDFs as well as PCBs and PCQs were detected in all blood samples. These identified isomers have been reported to be remarkably highly toxic compounds, i.e., both the 2,3,7,8-tetrachlorinated and 2,3,4,7,8-pentachlorinated compounds are toxicologically hundreds to thousands of times more toxic than PCB. In view of the high toxicity of PCDFs found in the Yu-Cheng patients' blood, it is concluded that they are the primary causal agents of Yusho as well as of the Yu-Cheng incident.

  14. Toxicity in Chironomus tentans larvae from exposure to sediments containing PAHs, PCBs and PCDDs/PCDFs

    SciTech Connect

    O`Keefe, P.W.; Wood, L.W.; Bush, B.; Hong, C.S.

    1994-12-31

    Sediments were collected in the Massena area of the St. Lawrence River near an effluent discharge point from an aluminum manufacturing plant (A) and opposite a waste disposal site associated with a plant manufacturing die-cast aluminum parts for the automotive industry (B). The Grasse River is a tributary of the St. Lawrence River and an additional sediment sample was collected in the Grasse River near the discharge point of a second aluminum plant (C). The plant A sediment contained high concentrations of PAHs (3,234 mg/kg), PCBs (702 mg/kg) and PCDFs (1652 ng/g) and there were no survivors when Chironomus tentans larvae at the 3{sup rd} instar stage were exposed to a dilution of 33% of the sediment in control sediment for 2 weeks. Even a 3--6 dilution of this sediment resulted in 75% mortality while the mortalities for exposure to the undiluted sediments from plants B and C were 50% and < 20% respectively. However the PAH and PCB concentrations in larvae exposed to the undiluted sediments from plants B and C were comparable or lower (PAHs in plant B sediment) than concentrations of the same compounds in larvae exposed to the diluted plant A sediment. Differences in the concentrations of coplanar PCBs may account for the higher toxicity of the plant A sediment. Toxicity contributions from 2,3,7,8-substituted PCDFs appear to be negligible.

  15. Determination of PCDDs, PCDFs, and PCBs in California peregrine falcons (Falco peregrinus) and their eggs

    SciTech Connect

    Jarman, W.M.; Burns, S.A. ); Chang, R.R.; Stephens, R.D. ); Norstrom, R.J.; Simon, M. ); Linthicum, J. )

    1993-01-01

    Levels of organochlorine compounds; polychlorinated biphenyls (PCBs), including nonortho congeners; polychlorinated dibenzo-p-dioxins (PCDDs); and polychlorinated dibenzofurans (PCDFs) were determined in seven California peregrine falcon eggs (Falco peregrinus) collected form five sites between the years 1983 to 1988; one immature falcon was analyzed for PCDDs and PCDGs only. All of the identified PCDDs and PCDFs were 2,3,7,8-substituted. The major PCDD and PCDF congeners identified in the eggs were 1,2,3,7,8-pentachlorodibenzo-p-dioxin (1,2,3,7,8-PnCDD) at a geometric mean value of 11 ng/kg, 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (1,2,3,6,7,8-HxCDD) at a mean value of 11 ng/kg 2,3,7,8-tetrachlorodibenzofuran (TCDF) at a mean value of 6.2 ng/kg, and 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PnCDF) at a level of 6.5 ng/kg. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) was present at a mean value of 5.7 ng/kg. Values of p,p[prime]-DDE in the eggs ranged from 7,100 to 26,000 [mu]g/kg, with a mean value of 12,000 [mu]g/kg. [Sigma]PCB levels ranged from 1,400 to 13,000 [mu]g/kg, with a mean value of 4,800 [mu]g/kg. The mean values of the non-ortho congeners 3,4,4[prime]-trichlorobiphenyl (PCB 37); 3,3[prime]4, 4[prime]-tetrachlorobiphenyl (PCB 77); 3,3[prime]4, 4[prime]5-pentachlorobiphenyl (PCB 126); and 3,3[prime]4, 4[prime],5,5[prime]-hexachlorobiphenyl (PCB 169) were 0.18, 0.93, 1.0, and 0.14 [mu]g/kg, respectively. TCDD equivalents (TEQs) were calculated for the mean values of PCDDs, PCDFs, and non-ortho-PCBs in the eggs. Total TEQs in the eggs was 120 ng/kg; PCB 126 accounted for 83% of the TEQs.

  16. Levels of toxic PCBs, PCDDs and PCDFs in biotic and abiotic samples from Galveston Bay, Texas

    SciTech Connect

    Gardinali, P.; Wade, T.

    1995-12-31

    Concentrations of di-, mono-, non-ortho PCB congeners as well as the seventeen 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) were measured in American oyster, blue crab, hardhead catfish liver and sediment samples collected from five sites in the Galveston Bay System. In general, when measuring sediments and sentinel organisms, a geographical gradient of contaminant load is observed between the heavily industrialized and the open bay sites. Although sediment concentrations are relatively low at most stations, toxic PCBs, PCDDs and PCDFs are strongly bioconcentrated in all three organisms analyzed. Levels of 2,3,7,8-TCDD ranged from 1.15 to 16.4 pg/g in the oysters, 1.10 to 138 pg/g in the blue crabs and, 11.0 to 101 pg/g in the catfish livers. 2,3,7,8-TCDD concentrations in sediments ranged from non-detected to 4.44 pg/g. Concentrations of 2,3,7,8-TCDF ranged from 2.31 to 50.6 pg/g in the oysters, 5.77 to 385 pg/g in the blue crabs and, 5.57 to 8.04 pg/g in the catfish livers, while sediment concentrations were between 0.65 to 7.46 pg/g. When the toxicity equivalent factor (TEF) approach was used to estimate the 2,3,7,8-TCDD toxic equivalents (TEQs), the non-ortho PCB congeners were the major TEQ contributors for the all organisms (29 to 74%). In contrast, the TEQ for the sediment samples were largely dominated by the contribution from PCDDs and PCDFs. The results also suggest that oysters, in spite of their lower concentrations, are more valuable for biomonitoring the availability of halogenated aromatic hydrocarbon contaminants.

  17. Occurrence, profile and possible sources of PCNs in Hong Kong soils, and a comparison with PCBs, PCDDs and PCDFs.

    PubMed

    Liu, Guorui; Zheng, Minghui; Cai, Zongwei

    2014-12-01

    Polychlorinated naphthalenes (PCNs) have been proposed for inclusion in the annexes of the Stockholm Convention by the European Union, signifying a probable increase in monitoring PCN levels at a global level. Investigations on PCN levels in the environment of Hong Kong have not been reported. In this preliminary investigation, PCN levels in surface soils samples were determined by isotope dilution HRGC/HRMS techniques, and compared with those of polychlorinated biphenyl (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). The concentrations of PCNs in the soil samples were 35-883 pg g(-1) (average, 201; and median, 94 pg g(-1)), which were lower than those of PCBs PCDDs and PCDFs. This comparison suggested that PCNs are currently not priority POPs compared with dioxins and PCBs in Hong Kong soils. PCDDs were the most important contributor to the sum of toxic equivalents of PCNs, PCBs, PCDDs and PCDFs. OCDD was the most dominant dioxin congener in Hong Kong surface soils. PCB-118 was the most abundant in 12 dl-PCB congeners. PCN congeners indicating thermal related sources (CN52/60, CN66/67 and CN73) were relatively abundant in their respective homologs, which suggested PCN contamination from thermal sources. The ratio of CN73 to CN74 in soil samples suggested the contribution of PCN contaminations in soils from both thermal-related sources and evaporative emissions of technical PCN mixtures.

  18. Levels of PCDDs and PCDFs in human milk from populations in Madrid and Paris

    SciTech Connect

    Gonzalez, M.J.; Hernandez, L.M.; Jimenez, B.

    1996-02-01

    Human breast milk represents a good substrate to examine the polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) background contamination of a population and also supplies important information about the exposure risk for nursing infants. Although adipose tissue and blood samples are commonly studied in the literature milk Dioxin levels are more specifically of concern because of the facility of sampling and also the potential health damage which may be caused to the breastfed babies by those highly toxic synthetic chemicals. The occurrence of dioxins in mother milk among the general population in all countries studied until now, has confirmed a widespread pollution and intake of those compounds. Dietary and other sources such as contaminated chemicals, industrial activity, waste combustion and leaded car gasoline may be responsible for such a contamination, and also for the differences among levels found in different countries. Human contamination by PCDDs and PCDFs from the environment is clearly a multisource problem. Human milk as well as other human fluids studies up to know have only found the presence of 2,3,7,8 substituted PCDD or PCDF congeners present. The reason for this congener specific retention is usually explained by the metabolic conversion on the 2,3,7, and 8 lateral positions in combination with high binding affinities for the cytosolic receptor proteins.

  19. Levels of PCDDs, PCDFs, and dioxin-like PCBs in human milk among Hong Kong mothers.

    PubMed

    Wong, Tze Wai; Wong, Andromeda H S; Nelson, E Anthony S; Qiu, Hong; Ku, Susanna Y K

    2013-10-01

    Dioxins are a family of persistent organic pollutants (POPs) listed under the Stockholm Convention, and include PCDDs, PCDFs, and dioxin-like PCBs. These toxic chemicals are carcinogenic, widely dispersed, and have long half-lives. They have contaminated the food web and, being fat-soluble, accumulate in adipose tissues and milk in the human body. To assess human exposure, we collected breast milk samples from 137 first-time mothers recruited from around Hong Kong. Samples were analysed by HRGC-HRMS in four pools, according to the subject's age and length of residency. Exposure was related to age, duration of stay, and possibly diet. Generally, older mothers, and mothers with a longer stay in Hong Kong, had higher levels of dioxins in their milk. This pattern was clearest for the PCBs, although deviations were observed for some of the PCDD/Fs. Mean concentrations, measured per gram of lipid weight in terms of WHO toxic equivalents (WHO-TEQs), were 7.48 pg/g for PCDD/Fs and 3.79 pg/g for PCBs, giving a total of 11.27 pg/g for PCDD/Fs and PCBs combined. Compared to an earlier Hong Kong study we conducted in 2002, the mean WHO-TEQ values in our latest findings were about 9% lower overall for PCDD/Fs and 19% lower for PCBs, with the mean total WHO-TEQ for PCDD/Fs and PCBs being around 13% lower in this study. This indicates a general declining trend in the levels of POPs in Hong Kong. However, our levels were still high when compared to those in some other Asian-Pacific countries. More stringent policies on reducing and eliminating POPs should help to lower these. Continued surveillance for POPs in human milk, as well as in common foodstuffs, will provide us with important information on human exposures that will be necessary for tracking our progress, and making future health risk assessments.

  20. Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife

    USGS Publications Warehouse

    Van Den, Berg, M.; Birnbaum, L.; Bosveld, A.T.C.; Brunstrom, B.; Cook, P.; Feeley, M.; Giesy, J.P.; Hanberg, A.; Hasegawa, R.; Kennedy, S.W.; Kubiak, T.; Larsen, J.C.; Van Leeuwen, F. X. R.; Liem, A.K.D.; Nolt, C.; Peterson, R.E.; Poellinger, L.; Safe, S.; Schrenk, D.; Tillitt, D.; Tysklind, M.; Younes, M.; Waern, F.; Zacharewski, T.

    1998-01-01

    An expert meeting was organized by the World Health Organization (WHO) and held in Stockholm on 15-18 June 1997. The objective of this meeting was to derive consensus toxic equivalency factors (TEFs) for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxinlike polychlorinated biphenyls (PCBs) for both human, fish, and wildlife risk assessment. Based on existing literature data, TEFs were (re)evaluated and either revised (mammals) or established (fish and birds). A few mammalian WHO-TEFs were revised, including 1,2,3,7,8-pentachlorinated DD, octachlorinated DD, occachlorinated DF, and PCB 77. These mammalian TEFs are also considered applicable for humans and wild mammalian species. Furthermore, it was concluded that there was insufficient in vivo evidence to continue the use of TEFs for some di-ortho PCBs, as suggested earlier by Ahlborg et al. In addition, TEFs for fish and birds were determined. The WHO working group attempted to harmonize TEFs across different taxa to the extent possible. However, total synchronization of TEFs was not feasible, as there were orders of a magnitude difference in TEFs between taxa for some compounds. In this respect, the absent or very low response of fish to mono-ortho PCBs is most noticeable compared to mammals and birds. Uncertainties that could compromise the TEF concept were also reviewed, including nonadditive interactions, differences in shape of the dose-response curve, and species responsiveness. In spite of these uncertainties, it was concluded that the TEF concept is still the most plausible and feasible approach for risk assessment of halogenated aromatic hydrocarbons with dioxinlike properties.

  1. Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife.

    PubMed Central

    Van den Berg, M; Birnbaum, L; Bosveld, A T; Brunström, B; Cook, P; Feeley, M; Giesy, J P; Hanberg, A; Hasegawa, R; Kennedy, S W; Kubiak, T; Larsen, J C; van Leeuwen, F X; Liem, A K; Nolt, C; Peterson, R E; Poellinger, L; Safe, S; Schrenk, D; Tillitt, D; Tysklind, M; Younes, M; Waern, F; Zacharewski, T

    1998-01-01

    An expert meeting was organized by the World Health Organization (WHO) and held in Stockholm on 15-18 June 1997. The objective of this meeting was to derive consensus toxic equivalency factors (TEFs) for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxinlike polychlorinated biphenyls (PCBs) for both human, fish, and wildlife risk assessment. Based on existing literature data, TEFs were (re)evaluated and either revised (mammals) or established (fish and birds). A few mammalian WHO-TEFs were revised, including 1,2,3,7,8-pentachlorinated DD, octachlorinated DD, octachlorinated DF, and PCB 77. These mammalian TEFs are also considered applicable for humans and wild mammalian species. Furthermore, it was concluded that there was insufficient in vivo evidence to continue the use of TEFs for some di-ortho PCBs, as suggested earlier by Ahlborg et al. [Chemosphere 28:1049-1067 (1994)]. In addition, TEFs for fish and birds were determined. The WHO working group attempted to harmonize TEFs across different taxa to the extent possible. However, total synchronization of TEFs was not feasible, as there were orders of a magnitude difference in TEFs between taxa for some compounds. In this respect, the absent or very low response of fish to mono-ortho PCBs is most noticeable compared to mammals and birds. Uncertainties that could compromise the TEF concept were also reviewed, including nonadditive interactions, differences in shape of the dose-response curve, and species responsiveness. In spite of these uncertainties, it was concluded that the TEF concept is still the most plausible and feasible approach for risk assessment of halogenated aromatic hydrocarbons with dioxinlike properties. PMID:9831538

  2. Identification, Quantification, and Toxicity of PCDDs and PCDFs in Soils from Industrial Areas in the Central and Eastern Regions of Saudi Arabia.

    PubMed

    Al-Wabel, Mohammad I; El-Saeid, Mohamed H; Usman, Adel R A; Al-Turki, Ali M; Ahmad, Mahtab; Hassanin, Ashraf S; El-Naggar, Ahmed H; Alenazi, Khaled K H

    2016-05-01

    This study was conducted to identify and quantify polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in soil samples collected from selected industrial areas in the central and eastern regions of Saudi Arabia. All the investigated compounds of PCDDs/PCDFs were identified in the studied locations. The average concentrations of PCDDs (sum of seven congeners measured) ranged from 11.5 to 59.6 pg g(-1), with a maximum concentration of 125.7 pg g(-1) at an oil refinery station followed by 100.9 pg g(-1) at a cement factory. The average concentrations of PCDFs (sum of 10 congeners measured) accounted for 11.68-19.35 pg g(-1), with a maximum concentration of 38.67 pg g(-1) at the cement factory. It was generally observed that the soil samples collected from industrial areas have substantially high toxicity equivalence (TEQ) values of PCDDs/PCDFs compared to soils of remote areas. Principal component analysis revealed that the cement factories and oil refineries were the primary sources of PCDDs and PCDFs. PMID:27010396

  3. Annual variation in the levels of metals and PCDD/PCDFs in soil and herbage samples collected near a cement plant.

    PubMed

    Schuhmacher, M; Agramunt, M C; Bocio, A; Domingo, J L; de Kok, H A M

    2003-07-01

    In May 2000, the levels of a number of metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sn, Tl, V and Zn) and polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in soil and herbage samples collected near a cement plant from Sta. Margarida i els Monjos (Catalonia, Spain). To determine the temporal variation in the concentrations of metals and PCDD/PCDFs, in May 2001 soil and herbage samples were again collected at the same sampling points and analyzed for the levels of metals and PCDD/PCDFs. In general terms, metal concentrations in soils did not change between May 2000 and May 2001, while significant decreases in the levels of Cr, Ni and V were found in herbage. On the other hand, no significant differences in the mean I-TEQ values of PCDD/PCDFs were found in soil and herbage samples. The results of this survey show that according to the annual variation in the levels of metals and PCDD/PCDFs the environmental impact of the cement plant on the area under its direct influence is not relevant.

  4. Dietary exposure to PCDD/PCDFs by individuals living near a hazardous waste incinerator in Catalonia, Spain: temporal trend.

    PubMed

    Martí-Cid, Roser; Bocio, Ana; Domingo, José L

    2008-02-01

    The levels of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were measured in foodstuffs randomly acquired in July 2006 in various locations of Tarragona County (Catalonia, Spain), which are near a hazardous waste incinerator (HWI). A total of 35 composite samples, belonging to various food groups (vegetables, pulses, cereals, fruits, fish and seafood, meat and meat products, eggs, milk, dairy products, and oils and fats) were analyzed by HRGC/HRMS. The dietary intake of PCDD/PCDFs was subsequently determined and compared with a previous survey performed in 2002. For calculations, recent data on consumption of the selected food items were used. Total dietary intake of PCDD/PCDFs for the general population of Tarragona County was estimated to be 27.81 pg WHO-TEQ/day, value notably lower than that found in the 2002 study, 63.80 pg WHO-TEQ/day. Fish and seafood (28%), oils and fats (22%), eggs (17%), and dairy products (11%) were the most important contributors to this intake, while pulses (1%), milk (2%), vegetables (3%) and fruits (3%) showed the lowest contribution to total WHO-TEQ. The current PCDD/PCDF intake is also considerably lower than the intake estimated in 1998 for the population of the same geographical area, 210.1 pg I-TEQ/day, when a baseline study was carried out during the construction of the HWI. The present intake is also compared with the dietary intakes of PCDD/PCDFs recently (2006-2007) reported for a number of regions and countries.

  5. A Critical Review about Human Exposure to Polychlorinated Dibenzo-p-Dioxins (PCDDs), Polychlorinated Dibenzofurans (PCDFs) and Polychlorinated Biphenyls (PCBs) through Foods.

    PubMed

    Fernández-González, R; Yebra-Pimentel, I; Martínez-Carballo, E; Simal-Gándara, J

    2015-01-01

    Dioxins include polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and part of polychlorinated biphenyls (PCBs). Only the compounds that are chlorinated at the 2,3,7, and 8 positions have characteristic dioxin toxicity. PCDDs, PCDFs and PCBs accumulate in the food chain due to their high lipophilicity, high stability, and low vapor pressure. They are not metabolized easily; however their hydroxylated metabolites are detected in feces. They cause a wide range of endocrine disrupting effects in experimental animals, wildlife, and humans. Endocrine related effects of PCDDs, PCDFs and PCBs on thyroid hormones, neurodevelopment and reproductive development were referenced. In addition, some studies of contamination of foods, bioaccumulation, dietary exposure assessment, as well as challenges of scientific research in these compounds were reviewed.

  6. Passerine exposure to primarily PCDFs and PCDDs in the river floodplains near Midland, Michigan, USA.

    PubMed

    Fredricks, Timothy B; Zwiernik, Matthew J; Seston, Rita M; Coefield, Sarah J; Plautz, Stephanie C; Tazelaar, Dustin L; Shotwell, Melissa S; Bradley, Patrick W; Kay, Denise P; Giesy, John P

    2010-05-01

    House wren (Troglodytes aedon), tree swallow (Tachycineta bicolor), and eastern bluebird (Sialia sialis) tissues collected in study areas (SAs) downstream of Midland, Michigan (USA) contained concentrations of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) greater than in upstream reference areas (RAs) in the region. The sum of concentrations of PCDD/DFs (SigmaPCDD/DFs) in eggs of house wrens and eastern bluebirds from SAs were 4- to 22-fold greater compared to those from RAs, whereas concentrations in tree swallow eggs were similar among areas. Mean concentrations of SigmaPCDD/DFs and sum 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (SigmaTEQs(WHO-Avian)), based on 1998 WHO avian toxic equivalency factors, in house wren and eastern bluebird eggs ranged from 860 (430) to 1500 (910) ng/kg wet weight (ww) and 470 (150) to 1100 (510) ng/kg ww, respectively, at the most contaminated study areas along the Tittabawassee River, whereas mean concentrations in tree swallow eggs ranged from 280 (100) to 760 (280) ng/kg ww among all locations. Concentrations of SigmaPCDD/DFs in nestlings of all studied species at SAs were 3- to 50-fold greater compared to RAs. Mean house wren, tree swallow, and eastern bluebird nestling concentrations of SigmaPCDD/DFs and SigmaTEQs(WHO-Avian) ranged from 350 (140) to 610 (300) ng/kg ww, 360 (240) to 1100 (860) ng/kg ww, and 330 (100) to 1200 (690) ng/kg ww, respectively, at SAs along the Tittabawassee River. Concentrations of SigmaTEQs(WHO-Avian) were positively correlated with SigmaPCDD/DF concentrations in both eggs and nestlings of all species studied. Profiles of relative concentrations of individual congeners were dominated by furan congeners (69-84%), primarily 2,3,7,8-tetrachlorodibenzofuran and 2,3,4,7,8-pentachlorodibenzofuran, for all species at SAs on the Tittabawassee and Saginaw rivers but were dominated by dioxin congeners at upstream RAs.

  7. Passerine Exposure to Primarily PCDFs and PCDDs in the River Floodplains Near Midland, Michigan, USA

    PubMed Central

    Zwiernik, Matthew J.; Seston, Rita M.; Coefield, Sarah J.; Plautz, Stephanie C.; Tazelaar, Dustin L.; Shotwell, Melissa S.; Bradley, Patrick W.; Kay, Denise P.; Giesy, John P.

    2009-01-01

    House wren (Troglodytes aedon), tree swallow (Tachycineta bicolor), and eastern bluebird (Sialia sialis) tissues collected in study areas (SAs) downstream of Midland, Michigan (USA) contained concentrations of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) greater than in upstream reference areas (RAs) in the region. The sum of concentrations of PCDD/DFs (ΣPCDD/DFs) in eggs of house wrens and eastern bluebirds from SAs were 4- to 22-fold greater compared to those from RAs, whereas concentrations in tree swallow eggs were similar among areas. Mean concentrations of ΣPCDD/DFs and sum 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (ΣTEQsWHO-Avian), based on 1998 WHO avian toxic equivalency factors, in house wren and eastern bluebird eggs ranged from 860 (430) to 1500 (910) ng/kg wet weight (ww) and 470 (150) to 1100 (510) ng/kg ww, respectively, at the most contaminated study areas along the Tittabawassee River, whereas mean concentrations in tree swallow eggs ranged from 280 (100) to 760 (280) ng/kg ww among all locations. Concentrations of ΣPCDD/DFs in nestlings of all studied species at SAs were 3- to 50-fold greater compared to RAs. Mean house wren, tree swallow, and eastern bluebird nestling concentrations of ΣPCDD/DFs and ΣTEQsWHO-Avian ranged from 350 (140) to 610 (300) ng/kg ww, 360 (240) to 1100 (860) ng/kg ww, and 330 (100) to 1200 (690) ng/kg ww, respectively, at SAs along the Tittabawassee River. Concentrations of ΣTEQsWHO-Avian were positively correlated with ΣPCDD/DF concentrations in both eggs and nestlings of all species studied. Profiles of relative concentrations of individual congeners were dominated by furan congeners (69–84%), primarily 2,3,7,8-tetrachlorodibenzofuran and 2,3,4,7,8-pentachlorodibenzofuran, for all species at SAs on the Tittabawassee and Saginaw rivers but were dominated by dioxin congeners at upstream RAs. Electronic supplementary material The online version of this article (doi:10

  8. A comparison of TEQ contributions from PCDDs, PCDFs and dioxin-like PCBs in sewage sludges from Catalonia, Spain.

    PubMed

    Eljarrat, E; Caixach, J; Rivera, J

    2003-05-01

    Eight sewage sludges from rural, urban and industrial wastewater treatment plants (WWTPs) in Catalonia (Spain) were analysed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) to determine the present levels of contamination. A method based on an automated cleanup system followed by an isotope-dilution high-resolution mass spectrometric analysis was employed. Total toxicity equivalent (WHO-TEQ) values were calculated using the toxicity equivalent factors (WHO-TEFs) proposed by WHO for dioxin-like PCBs, PCDDs and PCDFs. The WHO-TEQ(PCDD/F) values for these samples ranged from 4.9 to 20.8 pg/g dry weight (d.w.), with a mean value of 9.3 pg/g d.w., whereas WHO-TEQ(PCB) levels ranged between 1.9 and 6.6 pg/g d.w., with a mean value of 4.2 pg/g d.w. The WHO-TEQ(PCB) contribution varied from 13% to 50%, suggesting that PCB contribution on the toxicity of the samples must be taken into account. Moreover, these contemporary PCDD, PCDF and PCB concentrations were compared with previous data obtained from sewage sludge samples collected during the 80s. Our findings show that contemporary PCDD, PCDF and PCB levels have declined since the 80s.

  9. Determination of toxic congeners of 17 PCDDs/PCDFs and 12 dl-PCBs using polyurethane foam passive air samplers in ten cities around Seoul.

    PubMed

    Yoonki, Min; Jongwon, Heo; Meehye, Lee

    2014-09-01

    Twenty-nine toxic congeners including 17 polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were determined using passive air samplers (PAS) at ten satellite cities of Seoul for two years. Chemical analysis was done by high resolution gas chromatography (HRGC) coupled with high resolution mass spectrometry (HRMS). The ten monitoring sites represent urban-residential, industrial, urban-rural mixed, and rural types of regions in Gyeonggi Province, Republic of Korea. The concentrations of PCDDs/PCDFs and dioxin-like PCBs ranged from 0.59 pg·day(-1) to 29.7 pg·day(-1) and from 3.44 pg·day(-1) to 99.7 pg·day(-1), respectively with the highest values at industrial areas. The relative abundance of more toxic congeners (tetra- and penta-chlorinated PCDDs/PCDFs) was the highest in urban-rural mixed group despite the less emission sources than industrial group. It implies that this group was under the influence of fugitive emissions that have not yet been identified or regulated. This study reports the first attempt of atmospheric PCDDs/PCDFs and dl-PCB measurements with PAS in the monitoring network of Korea, which highlights the efficacy of PAS in continuous and long-term monitoring of those species particularly at regions that could easily slip out of environmental governance or of low accessibility to monitoring.

  10. Bioavailability of PCDDs and PCDFs of fly ash after semi-chronic oral ingestion by guinea pig and Syrian golden hamster

    SciTech Connect

    van den Bery, M.; de Vroom, E.; Olie, K.; Hutzinger, O.

    1986-01-01

    Groups of guinea pigs and syrian golden hamster were fed 2.5% HCl pre-treated fly ash from the electrostatic precipitator of a municipal incinerator during one, two, and three months, respectively, in the diet. The livers were analyzed for tetra-, penta-, and hexa-chlorinated dibenzo(p)dioxines (PCDDs) and dibenzofurans (PCDFs). In the livers of the hamsters 2,3,7,8-substituted PCDDs and PCDFs were the major isomers retained. In the livers of the guinea pigs 2,3,7,8 substituted PCDDs and PCDF congeners were retained, but also a number of otherwise substituted PCDFs. The PCDF congener which had the highest retention in the livers of guinea pigs was 1,2,3,7,8-PnCDF, 11.3% after 95 days. In the livers of the hamsters highest retention was found for 2,3,4,7,8-PnCDF, 8.4% after 95 days. For most 2,3,7,8-substituted PCDDs and PCDFs the retention in the livers of the guinea pigs and hamsters was not significantly different during the whole period, which could indicate a bioconcentration approaching a linear relationship to the administered dose. Constant relative concentrations in the livers were found for the 2,3,7,8-substituted penta- and hexa-chlorinated PCDDs and PCDF in both species during the three time periods.

  11. Assessment of health effects in New York City firefighters after exposure to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs): the Staten Island Transformer Fire Health Surveillance Project.

    PubMed

    Kelly, Kerry J; Connelly, Edmond; Reinhold, Gustave A; Byrne, Mike; Prezant, David J

    2002-01-01

    Following an electrical transformer fire in Staten Island, New York, a health surveillance program was established for 60 New York City firefighters and emergency medical technicians exposed to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs). Exposure potential was documented after high levels of PCBs and PCDFs were found on transformer and firefighters' uniforms. Personnel received comprehensive medical examinations, and the results were compared with preexposure values. Serum was analyzed for PCBs, PCDFs, and polychlorinated dibenzo-p-dioxins (PCDDs). Follow-up was conducted 9 mo later. Thirty-two of 58 (55%) firefighters reported initial symptoms, and 3 firefighters required brief medical leave. Pulmonary functions, exercise performance, serum liver functions, and serum lipid profiles were normal or unchanged from preexposure baselines. Serum PCBs averaged 2.92 +/- 1.96 ppb (range = 1.9-11.0 ppb). Five (8%) had serum PCBs that were greater than or equal to 6 ppb. Eight (73%) had a significant decrease (p = .05) in serum PCB level at the time of follow-up. Serum toxic equivalency (TEQ [1998 World Health Organization]) for total PCDDs and PCDFs averaged 39.0 +/- 21.5 (n = 48). Eighteen (38%) had elevated TEQs (i.e., > 40). All firefighters had no short-term heath effects. Modern firefighting uniforms are not meant to replace HAZMAT suits, but these uniforms provide protection from this chemical exposure for most firefighters. PMID:12530594

  12. Effects of oxygen, catalyst and PVC on the formation of PCDDs, PCDFs and dioxin-like PCBs in pyrolysis products of automobile residues.

    PubMed

    Joung, Hyun-Tae; Seo, Yong-Chil; Kim, Ki-Heon; Seo, Yong-Chan

    2006-11-01

    End-of-life vehicles are dismantled to recover reusable parts and then sent to a shredding facility for steel material recovery. The residue generated from the shredding process, so-called automobile shredder residue, is now being mostly disposed in landfill, however landfill will be prohibited in the near future. More recycling and energy recovery must be made by the regulation. The most appropriate method is the thermal treatment that will produce various forms of fuels and less volume of vitrified residue. In this research, an automobile shredder residue was simulated with considering the residue from a shredding factory based on the new vehicle and thermally treated by pyrolysis or gasification to observe the yields of gas, oil and char. In the temperature range of 400-800 degrees C, the yields of gas, oil, and char were 38.7-45.8%, 12.3-18.2%, and 36.0-49.0%, respectively. The optimum pyrolyzing temperature for more oil production was around 600 degrees C. Emission characteristics of the byproducts, PCDDs, PCDFs and dioxin-like PCBs were studied at the temperature of 600 degrees C. The analysis on the concentration and distribution of the isomers in various forms of the products were completed with and without oxygen, PVC, and catalytic metals, in order to observe how the existence of oxygen, PVC, and catalytic metals affect the formation of PCDDs, PCDFs, and dioxin-like PCBs from pyrolysis or gasification process. Without PVC, no PCDDs, PCDFs and dioxin-like PCBs were found in any products. PCDFs were predominant in any conditions. Catalyst and oxygen were found to affect to form more PCDDs, PCDFs, and dioxin-like PCBs. Effects of catalyst and oxygen on the byproduct formation seemed to be similar in oil and gas while that was different in char.

  13. Effects of oxygen, catalyst and PVC on the formation of PCDDs, PCDFs and dioxin-like PCBs in pyrolysis products of automobile residues.

    PubMed

    Joung, Hyun-Tae; Seo, Yong-Chil; Kim, Ki-Heon; Seo, Yong-Chan

    2006-11-01

    End-of-life vehicles are dismantled to recover reusable parts and then sent to a shredding facility for steel material recovery. The residue generated from the shredding process, so-called automobile shredder residue, is now being mostly disposed in landfill, however landfill will be prohibited in the near future. More recycling and energy recovery must be made by the regulation. The most appropriate method is the thermal treatment that will produce various forms of fuels and less volume of vitrified residue. In this research, an automobile shredder residue was simulated with considering the residue from a shredding factory based on the new vehicle and thermally treated by pyrolysis or gasification to observe the yields of gas, oil and char. In the temperature range of 400-800 degrees C, the yields of gas, oil, and char were 38.7-45.8%, 12.3-18.2%, and 36.0-49.0%, respectively. The optimum pyrolyzing temperature for more oil production was around 600 degrees C. Emission characteristics of the byproducts, PCDDs, PCDFs and dioxin-like PCBs were studied at the temperature of 600 degrees C. The analysis on the concentration and distribution of the isomers in various forms of the products were completed with and without oxygen, PVC, and catalytic metals, in order to observe how the existence of oxygen, PVC, and catalytic metals affect the formation of PCDDs, PCDFs, and dioxin-like PCBs from pyrolysis or gasification process. Without PVC, no PCDDs, PCDFs and dioxin-like PCBs were found in any products. PCDFs were predominant in any conditions. Catalyst and oxygen were found to affect to form more PCDDs, PCDFs, and dioxin-like PCBs. Effects of catalyst and oxygen on the byproduct formation seemed to be similar in oil and gas while that was different in char. PMID:16740293

  14. Annual and seasonal variations in atmospheric PCDDs/PCDFs and dioxin-like PCBs levels in satellite cities of Seoul, Korea during 2003-2009

    NASA Astrophysics Data System (ADS)

    Min, Yoonki; Lee, Meehye; Kim, Donggi; Heo, Jongwon

    2013-10-01

    Long-term measurements of atmospheric polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) were conducted in six satellite cities of Seoul, the capital of South Korea, from January 2003 to December 2009. Of the six sites, three were located in residential areas (Suwon, Anyang, and Seongnam) and the other three were in industrial areas (Ansan, Bucheon, and Siheung). For the 7 years, the average concentrations of PCDDs/PCDFs and dl-PCBs were higher at industrial sites than those at residential sites, and their lowest and highest concentrations were 0.113 ± 0.073 pg international toxicity equivalency quantity (I-TEQ) m-3 and 0.0071 ± 0.0040 pg World Health Organization (WHO)-TEQ m-3 at Seongnam and 0.625 ± 0.597 pg I-TEQ m-3 and 0.0376 ± 0.0285 pg WHO-TEQ m-3 at Ansan, respectively. The annual averages of these compounds tended to decrease from 2003 to 2009, with the most apparent change in 2006 when the regulation of dioxin emission standard was reinforced for flue gas from incineration facilities. Complying with the reinforced standard, the concentrations of PCDFs were reduced more effectively than those of PCDDs, leading to increase in ratios of PCDDs to PCDFs since 2006. Additionally, a seasonal tendency was observed for PCDDs/PCDFs with higher concentrations in winter than summer, which was opposite for dl-PCBs. This seasonal difference suggests their sources such as combustion processes and volatilization and the influence of synoptic-scale circulation. The congener profiles indicated that 1,2,3,4,6,7,8-HpCDF, OCDF, OCDD, and 1,2,3,4,6,7,8-HpCDD were the most abundant, comprising 65.0% of the 17 toxic 2,3,7,8-substituted PCDDs/PCDFs mass. The three congeners of 2,3‧,4,4‧,5-PeCB, 2,3,3‧,4,4‧-PeCB, and 3,3‧,4,4‧-TeCB comprised 75.9% of the 12 dl-PCBs.

  15. Global pollution monitoring of polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) using skipjack tuna as bioindicator.

    PubMed

    Ueno, Daisuke; Watanabe, Mafumi; Subramanian, Annamalai; Tanaka, Hiroyuki; Fillmann, Gilberto; Lam, Paul K S; Zheng, Gene J; Muchtar, Muswerry; Razak, Hamidah; Prudente, Maricar; Chung, Kyu-Hyuck; Tanabe, Shinsuke

    2005-07-01

    In order to elucidate the global distribution of dioxins and related compounds, such as PCDDs, PCDFs and coplanar PCBs, levels of these compounds were determined in the muscle of skipjack tuna (Katsuwonus pelamis) collected from the offshore waters and open seas near Japan, Taiwan, Philippines, Indonesia, Seychelles and Brazil, and the Japan Sea, the East China Sea, the South China Sea, the Indian Ocean and the North Pacific Ocean. PCDDs, PCDFs and coplanar PCBs were detected in almost all the specimens collected from all the locations surveyed, indicating widespread contamination by these compounds in the marine environment. Higher concentrations of dioxins and coplanar PCBs were detected in the samples from temperate Asian regions, plausibly due to larger usage and anthropogenic generation in highly industrialized countries around the East China Sea and the South China Sea, such as Japan, Korea, Taiwan, Hong Kong and coastal China.

  16. Intake and fecal excretion of PCDDs, PCDFs, HCB and PCBs (138, 153, 180) in a breast-fed and a formula-fed infant.

    PubMed

    Abraham, K; Hille, A; Ende, M; Helge, H

    1994-01-01

    Intake and fecal excretion of PCDDs, PCDFs, HCB and PCBs (IUPAC Nos. 138, 153, 180) were measured in a breast-fed and a formula-fed infant at the age of 1 and 5 months. As expected, the intake of these compounds was clearly higher in the breast-fed infant. In this baby an almost complete absorption was observed for lower chlorinated PCDDs and PCDFs and also for HCB and PCBs, whereas for hepta- and octachlorinated PCDDs and PCDFs fecal excretion was considerably higher (from 20% up to nearly 100% of the intake). Due to low concentrations in diet and feces of the formula-fed infant an evaluation was possible only for a few compounds at the age of 5 months. These values were in the same range when compared with those of the breast-fed infant. For collection of feces new cotton diapers were used which were pre-extracted in order to reduce the levels of polychlorinated compounds. Unexpectedly, after washing the tissue a much higher contamination was observed which made a calculation of fecal excretion rates in the formula-fed infant at the age of 1 month impossible. PMID:7850375

  17. Concentrations of PCDD/PCDFs and PCBs in fish and seafood from the Catalan (Spain) market: estimated human intake.

    PubMed

    Bocio, Ana; Domingo, José L; Falcó, Gemma; Llobet, Juan M

    2007-02-01

    The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) in samples from 14 fish and seafood species widely consumed by the population of Catalonia, Spain, were measured. These samples were randomly purchased independently of their geographical origin. The intake of PCDD/Fs and PCBs through consumption of these species was also estimated for various age and sex groups of this population. The highest and lowest levels of PCDD/Fs and dioxin-like PCBs (DL-PCBs) were found in red mullet and shrimp, respectively. For a standard adult man (70 kg body weight), the intake of PCDD/Fs plus DL-PCBs through consumption of fish and other seafood was estimated to be 38.0 pg WHO-TEQ/day. Tuna, hake, and sardine were the species with the highest contribution to this intake. The results of this study indicate that, in general terms, the dietary habits of the population of Catalonia (Spain) regarding fish and seafood consumption do not contribute remarkably to increase PCDD/F and DL-PCB intake.

  18. Levels of PCDD/PCDFs and PCBs in edible marine species and human intake: a literature review.

    PubMed

    Domingo, José L; Bocio, Ana

    2007-04-01

    Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) are lipophilic organic compounds whose origin comes from many different sources. PCDD/Fs and PCBs are ubiquitous and persistent environmental pollutants with a well known potential toxicity, which were included at the 1998 UN-EC POP protocol. Although human exposure to PCDD/Fs and PCBs can occur by various routes, food is the primary source. A number of studies have shown that the major food sources of these organic pollutants are fat-containing animal products, including fish and other seafood. Because of the frequent health recommendations concerning fish consumption, to determine the contribution to the dietary intake of chemical contaminants such as PCDD/Fs and PCBs through fish and other seafood consumption is an issue of special interest. This paper reviews the state of the science regarding recent literature on PCDD/F and PCB levels in marine species and human intake through fish and seafood consumption. The concentrations of these pollutants depend basically on the environment in which the respective species are caught. It is concluded that some groups of population frequently consuming high quantities of certain species could be significantly increasing health risks due to PCDD/F and PCB exposure.

  19. Atmospheric deposition of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in urban and suburban areas of Korea.

    PubMed

    Moon, Hyo-Bang; Lee, Su-Jeong; Choi, Hee-Gu; Ok, Gon

    2005-03-01

    Bulk atmospheric samples (wet and dry) were collected monthly throughout a year at urban and suburban areas of Korea to assess the deposition flux and seasonal variations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). The PCDDs/DFs deposition fluxes ranged from 1.0 to 3.7 ng TEQ/m2/year in the urban area and from 0.5 to 4.6 ng TEQ/m2/year in the suburban area. The deposition fluxes of PCDDs/DFs in this study were comparable to or lower than those previously reported at different locations. The atmospheric deposition fluxes of particles and PCDDs/DFs in winter tended to be higher than those in summer. However, monthly variations between particle and PCDDs/DFs deposition fluxes were small, and the correlation coefficients between the deposition fluxes of air particles and each homologue group of PCDDs/DFs varied according to the degree of chlorination of the homologue group. The deposition velocity of PCDDs/DFs in the urban area was estimated at 0.04 cm/s, which is a lower value than those found in other studies. The two most likely factors affecting the monthly variation of deposition fluxes are the ambient temperature and the amount of precipitation. In particular, the ambient temperature had an influence on the lower chlorinated homologues of PCDDs/DFs while precipitation had an influence on the higher chlorinated PCDDs/DFs. The PCDDs/DFs profiles in atmospheric deposition bulk samples showed a similar pattern at the urban and suburban sites. The possibility of the loading of PCDDs/DFs by Asian dust events could be partly confirmed by investigation of homologue profiles.

  20. Disposition of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in two Norwegian epibenthic marine food webs.

    PubMed

    Ruus, Anders; Berge, John Arthur; Bergstad, Odd Aksel; Knutsen, Jan Atle; Hylland, Ketil

    2006-03-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are a group of halogenated hydrocarbons, comprising 210 different, theoretically possible congeners. They are relatively hydrophobic and persistent to biodegradation, thereby rendering them subject to bioaccumulation. This study was conducted in Frierfjord and Eidangerfjord in the Grenland fjord system, Norway, heavily polluted by PCDD/PCDF discharges from the 16,600,859 magnesium production at Herøya from 1951 to 2001. Pooled samples of surface-sediments and the following organisms were collected for the Frierfjord and Eidangerfjord study areas: common shrimp (Crangon crangon), polychaetes (mainly Nereis diversicolor), shore crab (Carcinus maenas), cod (Gadus morhua), flounder (Platichthys flesus), trout (Salmo trutta), herring (Clupea harengus), benthic amphipods and zooplankton. Concentrations of 2,3,7,8-PCDD/Fs were quantified in pooled samples for all species. The relative abundances of stable isotopes of nitrogen (delta(15)N) were evaluated in the organisms as a measure of chemically-derived trophic level. Contrary to earlier studies on other persistent organochlorines, it was found that the concentrations of PCDD/Fs declined with increasing trophic level. Principal Component Analysis (PCA) also showed differences between species in the pattern of PCDD/Fs. Higher chlorinated congeners constituted lower percentages of the PCDD/F-concentrations higher in the food chain as compared to lower trophic levels. In general, congener patterns did not differ between fjords. Infauna (polychaetes) and zooplankton had congener patterns most similar to the pollution source. The results indicate lower accumulation of higher chlorinated congeners in species at higher trophic levels (fish), presumably due to low membrane permeability (high molecular size) and possibly slow transport through intestinal aqueous phases because of low aqueous solubility. PMID:16169571

  1. Occurrence of organochlorine contaminants (PCBs, PCDDs and PCDFs) and pathologic findings in loggerhead sea turtles, Caretta caretta, from the Adriatic Sea (Mediterranean Sea).

    PubMed

    Storelli, Maria M; Zizzo, Nicola

    2014-02-15

    Livers of 12 loggerhead sea turtles, Caretta caretta from the Eastern Mediterranean Sea (Adriatic Sea) were analyzed for the presence of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Pathological and microbiological studies were also carried out in order to provide a contribution to the knowledge of causes of Mediterranean turtle death. Boat-strike injuries, entanglement in derelict fishing nets and ingestion of hooks and monofilament lines are the causes of death most frequently observed. PCBs (average: 1,399 ng g(-1) fat basis) were the dominant chemicals, followed by PCDFs (average: 61 pg g(-1) fat basic) and PCDDs (average: 16 pg g(-1) fat basis). Hexachlorobiphenyl 153 accounted for the greatest proportion of the total PCBs, followed in order by PCB 138 and PCB 180 (14.1%). Mid-chlorinated, penta-through hepta-PCBs were among the top contributors to the sum of total PCBs, while the homolog pattern of PCCD/Fs was dominated by the tetra- to hexa-substituted congeners. In general the contamination level observed here was comparable with that reported in literature for specimens from different marine areas. Average TEQPCDD/Fs+Dl-PCBs concentration was 27.02 pg g(-1) wet weight (305.1 pg g(-1) lipid weight), with dioxin like-PCBs (93.4%) contributing much more to the total than PCDFs (3.9%) and PCDDs (2.7%). The appreciable concentration of TEQ would at first suggest that there are signs of potential threats to the health of these marine reptiles. Apart from PCBs, this is the first study documenting concentrations of PCDD/Fs in marine turtles from the Mediterranean Sea. Further investigations are urgently needed to characterize their contamination level for a better future protection and conservation of this endangered animal. PMID:24342092

  2. Occurrence of organochlorine contaminants (PCBs, PCDDs and PCDFs) and pathologic findings in loggerhead sea turtles, Caretta caretta, from the Adriatic Sea (Mediterranean Sea).

    PubMed

    Storelli, Maria M; Zizzo, Nicola

    2014-02-15

    Livers of 12 loggerhead sea turtles, Caretta caretta from the Eastern Mediterranean Sea (Adriatic Sea) were analyzed for the presence of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Pathological and microbiological studies were also carried out in order to provide a contribution to the knowledge of causes of Mediterranean turtle death. Boat-strike injuries, entanglement in derelict fishing nets and ingestion of hooks and monofilament lines are the causes of death most frequently observed. PCBs (average: 1,399 ng g(-1) fat basis) were the dominant chemicals, followed by PCDFs (average: 61 pg g(-1) fat basic) and PCDDs (average: 16 pg g(-1) fat basis). Hexachlorobiphenyl 153 accounted for the greatest proportion of the total PCBs, followed in order by PCB 138 and PCB 180 (14.1%). Mid-chlorinated, penta-through hepta-PCBs were among the top contributors to the sum of total PCBs, while the homolog pattern of PCCD/Fs was dominated by the tetra- to hexa-substituted congeners. In general the contamination level observed here was comparable with that reported in literature for specimens from different marine areas. Average TEQPCDD/Fs+Dl-PCBs concentration was 27.02 pg g(-1) wet weight (305.1 pg g(-1) lipid weight), with dioxin like-PCBs (93.4%) contributing much more to the total than PCDFs (3.9%) and PCDDs (2.7%). The appreciable concentration of TEQ would at first suggest that there are signs of potential threats to the health of these marine reptiles. Apart from PCBs, this is the first study documenting concentrations of PCDD/Fs in marine turtles from the Mediterranean Sea. Further investigations are urgently needed to characterize their contamination level for a better future protection and conservation of this endangered animal.

  3. Multiple Lines of Evidence Risk Assessment of Terrestrial Passerines Exposed to PCDFs and PCDDs in the Tittabawassee River Floodplain, Midland, Michigan, USA

    PubMed Central

    Fredricks, Timothy B.; Giesy, John P.; Coefield, Sarah J.; Seston, Rita M.; Tazelaar, Dustin L.; Roark, Shaun A.; Kay, Denise P.; Newsted, John L.; Zwiernik, Matthew J.

    2011-01-01

    A site-specific multiple lines of evidence risk assessment was conducted for house wrens (Troglodytes aedon) and eastern bluebirds (Sialia sialis) along the Tittabawassee River downstream of Midland, Michigan, where concentrations of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) in flood-plain soils and sediments are greater compared to upstream areas and some of the greatest anywhere in the world. Lines of evidence supporting the population-level assessment endpoints included site-specific dietary- and tissue-based exposure assessments and population productivity measurements during breeding seasons 2005–2007. While a hazard assessment based on site-specific diets suggested that populations residing in the downstream floodplain had the potential to be affected, concentrations in eggs compared to appropriate toxicity reference values (TRVs) did not predict a potential for population-level effects. There were no significant effects on reproductive success of either species. The most probable cause of the apparent difference between the dietary- and tissue-based exposure assessments was that the dietary-based TRVs were overly conservative based on intraperitoneal injections in the ring-necked pheasant. Agreement between the risk assessment based on concentrations of PCDFs and PCDDs in eggs and reproductive performance in both species supports the conclusion of a small potential for population-level effects at this site. PMID:21804755

  4. PCDDs, PCDFs and PCNs in products of microwave-assisted pyrolysis of woody biomass--Distribution among solid, liquid and gaseous phases and effects of material composition.

    PubMed

    Gao, Qiuju; Budarin, Vitaliy L; Cieplik, Mariusz; Gronnow, Mark; Jansson, Stina

    2016-02-01

    Microwave-assisted pyrolysis (MAP) of lignocellulosic biomass is a technique that could potentially be used to produce and upgrade renewable energy carriers. However, there is no available information about the formation of dioxins and other organic pollutants in MAP treatment of woody biomass. In this study, MAP experiments were conducted in lab-scale using virgin softwood, bark, and impregnated wood as feedstocks. The non-condensable gas, liquid (fractionated into aqueous and oil phases), and char fractions generated during pyrolysis were collected and analysed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and naphthalenes (PCNs). The concentrations of PCDDs, PCDFs and PCNs in the pyrolysis products ranged from 0.52 to 43.7 ng kg(-1). All investigated compound groups were most abundant in the oil fraction, accounting for up to 68% (w/w) of the total concentrations. The highest PCDD, PCDF and PCN concentrations were found from the pyrolysis of bark, which has relatively high contents of chlorine and mineral matter, followed by impregnated wood, which contains organic and metal-based preservatives. The homologue profiles of all three compound groups were dominated by the less chlorinated homologues. The homologue abundance decreased as the degree of chlorination increased. This trend was observed for all three feedstocks.

  5. Biochemical and toxic effects of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in the cormorant (Phalacrocorax carbo) after in ovo exposure

    SciTech Connect

    Berg, M. Van Den; Craane, B.L.H.J.; Sinnige, T. . Research Inst. of Toxicology)

    1994-05-01

    Ecological investigation revealed differences in breeding success of cormorants (Phalacrocorax carbo) between two colonies in the Netherlands. In this study the possible role of organohalogen pollutants was investigated. Thirty-nine cormorant eggs were collected from two colonies with marked differences in contamination. Seventeen cormorant eggs were hatched in an incubator. The respiration rate was monitored regularly during the incubation. Hatchlings were euthanized at day 1. Several morphological parameters were measured. PCBs and polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were analyzed in the yolk sac. Blood and liver were collected for analysis of cytochrome P450, ethoxyresorufin-O-deethylation (EROD) and pentoxyresorufin-O-depentylation (PROD) activities, vitamin A, and thyroid hormone levels. Residue levels differed two- to five-fold for PCBs and 25% for PCDDs and PCDFs between both colonies. Birds from the most contaminated colony showed an increase in ovo respiration rate, increased cytochrome P450 and EROD activity, and reduced plasma thyroid hormone and hepatic retinyl palmitate levels. Large interindividual differences were observed for all parameters. The data were compared on an individual basis (n = 17) to detect any concentration-effect relationships. Significant concentration-effect relationships were observed for EROD induction, plasma free thyroxine reduction, yolk sac weight, relative liver weight, and head size. It is concluded these compounds may, at least in part, have played a role in the observed low breeding success of cormorants.

  6. Artificial-turf playing fields: contents of metals, PAHs, PCBs, PCDDs and PCDFs, inhalation exposure to PAHs and related preliminary risk assessment.

    PubMed

    Menichini, Edoardo; Abate, Vittorio; Attias, Leonello; De Luca, Silvia; di Domenico, Alessandro; Fochi, Igor; Forte, Giovanni; Iacovella, Nicola; Iamiceli, Anna Laura; Izzo, Paolo; Merli, Franco; Bocca, Beatrice

    2011-11-01

    The artificial-turf granulates made from recycled rubber waste are of health concern due the possible exposure of users to dangerous substances present in the rubber, and especially to PAHs. In this work, we determined the contents of PAHs, metals, non-dioxin-like PCBs (NDL-PCBs), PCDDs and PCDFs in granulates, and PAH concentrations in air during the use of the field. The purposes were to identify some potential chemical risks and to roughly assess the risk associated with inhalation exposure to PAHs. Rubber granulates were collected from 13 Italian fields and analysed for 25 metals and nine PAHs. One further granulate was analysed for NDL-PCBs, PCDDs, PCDFs and 13 PAHs. Air samples were collected on filter at two fields, using respectively a high volume static sampler close to the athletes and personal samplers worn by the athletes, and at background locations outside the fields. In the absence of specific quality standards, we evaluated the measured contents with respect to the Italian standards for soils to be reclaimed as green areas. Zn concentrations (1 to 19 g/kg) and BaP concentrations (0.02 to 11 mg/kg) in granulates largely exceeded the pertinent standards, up to two orders of magnitude. No association between the origin of the recycled rubber and the contents of PAHs and metals was observed. The sums of NDL-PCBs and WHO-TE PCDDs+PCDFs were, respectively, 0.18 and 0.67×10(-5) mg/kg. The increased BaP concentrations in air, due to the use of the field, varied approximately from <0.01 to 0.4 ng/m(3), the latter referring to worst-case conditions as to the release of particle-bound PAHs. Based on the 0.4 ng/m(3) concentration, an excess lifetime cancer risk of 1×10(-6) was calculated for an intense 30-year activity. PMID:21907387

  7. Spatial and temporal changes of chlorinated pesticides, PCBs, dioxins (PCDDs/PCDFs) and brominated flame retardants in human breast milk from Northern Russia.

    PubMed

    Polder, A; Gabrielsen, G W; Odland, J Ø; Savinova, T N; Tkachev, A; Løken, K B; Skaare, J U

    2008-02-25

    This study presents for the first time temporal changes of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Russian human breast milk samples. Concentrations of OCPs and PCBs in samples from three locations in the North West of Russia in 2000-2002 (n=42), were compared to corresponding levels measured in 1993-1996 (n=58). In addition brominated flame retardants (BFRs), consisting of polybrominated diphenylethers (PBDEs) (including BDE-209) and hexabromocyclododecane (HBCD) were analysed in samples from 2000-2002 (n=37). The present levels of SigmaDDTs and SigmaHCHs were 5 and 10 times higher than corresponding levels in the neighbouring country Norway. Median concentrations of SigmaHCHs (196 microg/kg lw), SigmaCHBs (19.7 microg/kg lw) and SigmaPCBs(16) (316 microg/kg lw) were highest in Murmansk. The percentage of p,p'-DDT to SigmaDDTs and ratio DDE/DDT suggest possible ongoing use of DDT in Russia. Levels of PBDE were low and dominated by the congeners BDE-47 and BDE-153. The deca brominated BDE-209 was detected in all analysed samples (median concentration 0.19 microg/kg lipid). Levels of SigmaOCPs and SigmaPCBs decreased 56 and 30% in Murmansk and 36 and 43% in Arkhangelsk during the study period. The decline of SigmaOCPs was significant at both locations (p<0.05-p<0.0001). For SigmaPCBs, the decreasing trend was only significant in Arkhangelsk (p<0.0001). In addition, a decline of Sigmatotal TEQs (SigmaTEQs of PCDDs/PCDFs, non-ortho- and mono-ortho PCBs) was observed in Murmansk and Arkhangelsk during the study period. The exposure of infants by PCDDs/PCDFs and dioxin-like PCBs is still exceeding the daily tolerable intake (TDI) in North West Russia. However, the concentrations of PCDDs/PCDFs and dioxin-like PCBs seem to decline very rapidly.

  8. PCDDs, PCDFs, PCBs, OC pesticides and mercury in fish and osprey eggs from Willamette River, Oregon (1993, 2001 and 2006) with calculated biomagnification factors

    USGS Publications Warehouse

    Henny, C.J.; Kaiser, J.L.; Grove, R.A.

    2009-01-01

    The osprey (Pandion haliaetus) population nesting along the main stem Willamette River and lower Santiam River was first studied to evaluate contaminants and reproductive rates in 1993 when 78 occupied nests were present. By 2001, the population increased to 234 occupied nests, a 13.7% annual rate of population increase. A sample egg was collected from each of a series of nests along the Upper River (river mile 55-187) in 1993, 2001 and 2006 to evaluate trends of persistent contaminants (organochlorine [OC] pesticides, polychlorinated biphenyls [PCBs], polychlorinated dibenzo-p-dioxins [PCDDs], and polychlorinated dibenzofurans [PCDFs]). Nearly all OC pesticide residues decreased significantly, e.g., p, p?-DDE (DDE) from 2,350 to 1,353 to 210 ??g/kg wet weight (ww). PCBs followed a similar pattern over time, e.g., ???PCBs 688 to 245 to 182 ??g/kg ww, while PCDDs and PCDFs showed a more precipitous decline (often 85-95%) between 1993 and 2001, with no egg analyses warranted in 2006. During 2001-2002, sample osprey eggs were also collected from nests at three Headwater Reservoirs and two lower reaches (Newberg Pool and Tidal Portland) of the Willamette River, as well as the lower portion of the Santiam River to evaluate spatial residue patterns. Significant differences were seldom detected among the different sampling areas for OC pesticides (probably due to small sample sizes), although higher concentrations were often seen in the lower reaches, e.g., DDE 901 ??g/kg ww (Headwater Reservoirs), 1,353 (Upper River), 1,384 (Newberg Pool) and 2,676 (Tidal Portland). PCB congener concentrations in eggs were usually higher in the Tidal Portland reach than at other locations and often significantly higher than at the Headwater Reservoirs or Upper River. Mercury (first analyzed in eggs in 2001), PCDDs and PCDFs were extremely low in 2001/2002 with no significant spatial patterns. Whole fish composite samples of largescale sucker (Catastomus macrocheilus) and northern

  9. Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and organochlorine pesticides in yellow-blotched map turtle from the Pascagoula River basin, Mississippi, USA.

    PubMed

    Kannan, K; Ueda, M; Shelby, J A; Mendonca, M T; Kawano, M; Matsuda, M; Wakimoto, T; Giesy, J P

    2000-04-01

    Concentrations of polychlorinated-dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs), -biphenyls (PCBs), and organochlorine pesticides were measured in tissues of map turtles collected from two locations in the Pascagoula River drainage of Mississippi, USA. PCBs were most predominant among the organochlorines with a concentration of up to 99 ng/g, wet weight (580 ng/g, lipid weight) in livers. The greatest concentration of PCDDs/DFs of 1.1 pg/g, wet weight (15.76 pg/g, lipid weight) was found in the liver of a male turtle. The measured concentrations of organochlorines were less than those reported for turtles from the Great Lakes Basin and upper St. Lawrence River. PCBs contributed 90-99% of the total estimated 2, 3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs). Particularly, PCB congeners 105, 118, and 156 accounted for 68-80% of the estimated toxic potency of PCBs in turtles.

  10. PCDDs, PCDFs, PCBs, OC pesticides and mercury in fish and osprey eggs from Willamette River, Oregon (1993, 2001 and 2006) with calculated biomagnification factors.

    PubMed

    Henny, Charles J; Kaiser, James L; Grove, Robert A

    2009-02-01

    The osprey (Pandion haliaetus) population nesting along the main stem Willamette River and lower Santiam River was first studied to evaluate contaminants and reproductive rates in 1993 when 78 occupied nests were present. By 2001, the population increased to 234 occupied nests, a 13.7% annual rate of population increase. A sample egg was collected from each of a series of nests along the Upper River (river mile 55-187) in 1993, 2001 and 2006 to evaluate trends of persistent contaminants (organochlorine [OC] pesticides, polychlorinated biphenyls [PCBs], polychlorinated dibenzo-p-dioxins [PCDDs], and polychlorinated dibenzofurans [PCDFs]). Nearly all OC pesticide residues decreased significantly, e.g., p, p'-DDE (DDE) from 2,350 to 1,353 to 210 microg/kg wet weight (ww). PCBs followed a similar pattern over time, e.g., SigmaPCBs 688 to 245 to 182 microg/kg ww, while PCDDs and PCDFs showed a more precipitous decline (often 85-95%) between 1993 and 2001, with no egg analyses warranted in 2006. During 2001-2002, sample osprey eggs were also collected from nests at three Headwater Reservoirs and two lower reaches (Newberg Pool and Tidal Portland) of the Willamette River, as well as the lower portion of the Santiam River to evaluate spatial residue patterns. Significant differences were seldom detected among the different sampling areas for OC pesticides (probably due to small sample sizes), although higher concentrations were often seen in the lower reaches, e.g., DDE 901 microg/kg ww (Headwater Reservoirs), 1,353 (Upper River), 1,384 (Newberg Pool) and 2,676 (Tidal Portland). PCB congener concentrations in eggs were usually higher in the Tidal Portland reach than at other locations and often significantly higher than at the Headwater Reservoirs or Upper River. Mercury (first analyzed in eggs in 2001), PCDDs and PCDFs were extremely low in 2001/2002 with no significant spatial patterns. Whole fish composite samples of largescale sucker (Catastomus macrocheilus) and

  11. PCDDs, PCDFs, PCBs, OC pesticides and mercury in fish and osprey eggs from Willamette River, Oregon (1993, 2001 and 2006) with calculated biomagnification factors.

    PubMed

    Henny, Charles J; Kaiser, James L; Grove, Robert A

    2009-02-01

    The osprey (Pandion haliaetus) population nesting along the main stem Willamette River and lower Santiam River was first studied to evaluate contaminants and reproductive rates in 1993 when 78 occupied nests were present. By 2001, the population increased to 234 occupied nests, a 13.7% annual rate of population increase. A sample egg was collected from each of a series of nests along the Upper River (river mile 55-187) in 1993, 2001 and 2006 to evaluate trends of persistent contaminants (organochlorine [OC] pesticides, polychlorinated biphenyls [PCBs], polychlorinated dibenzo-p-dioxins [PCDDs], and polychlorinated dibenzofurans [PCDFs]). Nearly all OC pesticide residues decreased significantly, e.g., p, p'-DDE (DDE) from 2,350 to 1,353 to 210 microg/kg wet weight (ww). PCBs followed a similar pattern over time, e.g., SigmaPCBs 688 to 245 to 182 microg/kg ww, while PCDDs and PCDFs showed a more precipitous decline (often 85-95%) between 1993 and 2001, with no egg analyses warranted in 2006. During 2001-2002, sample osprey eggs were also collected from nests at three Headwater Reservoirs and two lower reaches (Newberg Pool and Tidal Portland) of the Willamette River, as well as the lower portion of the Santiam River to evaluate spatial residue patterns. Significant differences were seldom detected among the different sampling areas for OC pesticides (probably due to small sample sizes), although higher concentrations were often seen in the lower reaches, e.g., DDE 901 microg/kg ww (Headwater Reservoirs), 1,353 (Upper River), 1,384 (Newberg Pool) and 2,676 (Tidal Portland). PCB congener concentrations in eggs were usually higher in the Tidal Portland reach than at other locations and often significantly higher than at the Headwater Reservoirs or Upper River. Mercury (first analyzed in eggs in 2001), PCDDs and PCDFs were extremely low in 2001/2002 with no significant spatial patterns. Whole fish composite samples of largescale sucker (Catastomus macrocheilus) and

  12. Ambient air concentrations of PCDDs, PCDFs, coplanar PCBs, and PAHs at the Mississippi Sandhill Crane National Wildlife Refuge, Jackson County, Mississippi

    USGS Publications Warehouse

    White, D.H.; Hardy, J.W.

    1994-01-01

    Our objective was to determine the levels of selected airborne contaminants in ambient air at the Mississippi Sandhill Crane National Wildlife Refuge, Mississippi, that might be affecting the health of endangered cranes living there. Two high-volume air samplers were operated at separate locations on the Refuge during May?September 1991. The sampling media were micro-quartz filters in combination with polyurethane foam plugs. Composite bimonthly samples from each station were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Overall, residue concentrations were low. The toxic PCDD isomer 2,3,7,8-tetra-CDD was not detected, nor was penta-CDD. There was no difference (P>0.05) in residue concentrations between stations or over time and meteorological parameters were not correlated with residue concentrations. Because contaminant levels and patterns may differ seasonally, we recommend that air samples collected during winter months also be analyzed for these same chemical groups.

  13. Comparison of sulfuric acid treatment and multi-layer silica gel column chromatography in cleanup methods for determination of PCDDs, PCDFs and dioxin-like PCBs in foods.

    PubMed

    Amakura, Yoshiaki; Tsutsumi, Tomoaki; Sasaki, Kumiko; Toyoda, Masatake; Maitani, Tamio

    2002-10-01

    Two typical cleanup methods, sulfuric acid treatment and multi-layer silica gel column chromatography, for the determination of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) in seventeen food samples were examined and compared. Vegetables, fruits, cereals, fish, meat and dairy foods were extracted by conventional methods (shaking with acetone/n-hexane or with n-hexane after alkaline treatment). The extracts were cleaned up by sulfuric acid treatment or multi-layer silica gel column chromatography, followed by several column chromatographic steps. Of the samples treated, the vegetable, fruit and cereal samples could be directly applied to the multi-layer silica gel column after extraction. However, the samples containing fats and oils such as fish, meat and dairy foods needed to be treated several times with concentrated sulfuric acid before multi-layer column chromatography, because these samples plugged the column with oily residues. Both cleanup methods gave similar values of isomeric concentrations and showed similar efficiency of purification, and the recoveries ranged from 40 to 120%. These results are considered to provide useful data for the efficient analysis of dioxins in foods which have wide-ranging compositions.

  14. Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in water samples from the middle reaches of the Yangtze River, China.

    PubMed

    Zhang, Qin; Gao, Lirong; Zheng, Minghui; Liu, Lidan; Li, Cheng

    2014-05-01

    Few studies have been conducted to investigate the polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in freshwater since the volume of water needed for dioxin analysis is large. In this study, 19 water samples from the middle reaches of the Yangtze River were analysed for the levels of PCDD/Fs and dioxin-like PCBs (dl-PCBs). The results showed that the concentration ranges of PCDD/Fs and dl-PCBs were 0.6-8.5 and 2.0-15.8 pg/L, respectively, which were relatively low compared with those reported in the literature. The WHO-TEQ concentration range of dioxins was 0.002-0.040 pg/L. The PCA results indicated that the main sources of PCDD/Fs may be the applications of pentachlorophenol or sodium pentachlorophenate and domestic wood and coal burning. For dl-PCBs, domestic wood burning and coal burning were the main sources.

  15. Recent survey and effects of cooking processes on levels of PCDDs, PCDFs and Co-PCBs in leafy vegetables in Japan.

    PubMed

    Tsutsumi, Tomoaki; Iida, Takao; Hori, Tsuguhide; Nakagawa, Reiko; Tobiishi, Kazuhiro; Yanagi, Toshihiko; Kono, Yoichi; Uchibe, Hiroyasu; Matsuda, Rieko; Sasaki, Kumiko; Toyoda, Masatake

    2002-03-01

    We report here the latest levels of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) and coplanar polychlorinated biphenyls (Co-PCBs) in leafy vegetables in Japan as well as the effect of cooking processes on the reduction of these contaminants. Three kinds of leafy vegetables ("komatsuna", lettuce and spinach) from seven districts in Japan in 1998 were analyzed for the 2,3,7,8-chlorine substituted PCDD/Fs and three non-ortho-PCBs (#77, 126 and 169). The mean total TEQ levels (using the WHO-TEFs) in the komatsuna, lettuce and spinach were 0.094, 0.025 and 0.196 pg/g fresh weight, respectively. The TEQ levels are dominated by 2.3,7,8-TCDD, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3',4,4',5-PeCB in many of the samples. For one of these isomers, the 2,4,7,8-PeCDF TEQ levels showed good correlation with the total TEQ levels in the samples (r = 0.957). This suggests that 2,3,4,7,8-PeCDF may be an indicator for dioxin contamination in the analysis of the leafy vegetables. Also, the effects of two cooking processes (washing and washing followed by boiling) on the dioxin levels in two types of spinach samples were investigated. On average, in both samples, the total concentrations of the PCDDs, PCDFs and Co-PCB were reduced to about 38%, 73% and 88% of the initial concentrations by washing. and to 21%, 35%, and 61% of the initial concentrations by washing followed by boiling. The total TEQ levels were reduced to about 30% of the initial TEQ levels by washing followed by boiling. Significant reductions in the TEQ levels were observed in the cooked samples. Thus, the cooking processes may reduce the risk of dioxin intake from the leafy vegetables.

  16. Biomagnification factors (fish to Osprey eggs from Willamette River, Oregon, U.S.A.) for PCDDs, PCDFs, PCBs and OC pesticides.

    PubMed

    Henny, Charles J; Kaiser, James L; Grove, Robert A; Bentley, V Raymond; Elliott, John E

    2003-06-01

    A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in western Oregon was studied in 1993. The study was designed to determine contaminant concentrations in eggs, contaminant concentrations in fish species predominant in the Ospreys diet, and Biomagnification Factors (BMFs) of contaminants from fish species eaten to Osprey eggs. Ten Osprey eggs and 25 composite samples of fish (3 species) were used to evaluate organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). Mercury was also analyzed in fish. Geometric mean residues in Osprey eggs were judged low, e.g., DDE 2.3 microg g(-1) wet weight (ww), sigma PCBs 0.69 microg g(-1), 2,3,7,8-TCDD 2.3 ng kg(-1), and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presented by River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggs from the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the Cascade Mountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and Northern Pikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fish biomass in the Osprey diet sampled for contaminants (and fish eaten by Ospreys similar in size to those chemically analyzed), and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the large series of contaminants. BMFs ranged from no biomagnification (0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for the migratory

  17. Biomagnification factors (fish to osprey eggs from Willamette River, Oregon, U.S.A.) for PCDDS, PCDFS, PCBS, and OC pesticides

    USGS Publications Warehouse

    Henny, Charles J.; Kaiser, James L.; Grove, Robert A.; Bentley, V.R.; Elliot, J.E.

    2003-01-01

    A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g-1 wet weight (ww), PCBs 0.69 g g-1, 2,3,7,8-TCDD 2.3 ng kg-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident

  18. Levels of PCDDs, PCDFs and dl-PCBs in the blood of childbearing-aged women living in the vicinity of a chemical plant in Tianjin: a primary study.

    PubMed

    Chen, Xi; Chen, Jing-shan; Zhang, Lei; Li, Jing-guang; Yao, Lena; Self, Steven G; Sun, Xin; Tang, Nai-jun

    2015-01-01

    Several studies have suggested that maternal exposure to Polychlorinated dibenzo-p-dioxins (PCDDs), poly-chlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs) may affect foetal growth and infant development. The aim of our study was to determine whether the childbearing-aged residents living near a chemical plant have a greater exposure risk. Concentrations of 17 PCDD/Fs congeners and 12 non-ortho and mono-ortho dioxin-like PCBs were measured using HRGC-HRMS in the blood of 30 non-occupational childbearing-aged women living near a chemical plant (Dagu) that had been producing chlorinated pesticides from 1958 to 2004. The factors that influenced the body burden were investigated based on responses to a questionnaire. Levels of PCDD/Fs+PCBs were in the range of 16.43-155.29pg WHO 2005-TEQg(-1) lipid. PCDDs and PCDFs contributed 56.72% and 34.44%, respectively, to the total TEQ value. Total WHO-TEQ was approximately tenfold higher in the participants living in the vicinity of the plant (distance: 1.52±0.148km) than in the groups living farther away (distance: 4.93±1.124km). A negative correlation between total WHO-TEQ and distance to Dagu was observed by multiple linear regression models. The data provide basic information for monitoring dioxin-like chemicals in the district and for the future study of the relationship between POPs and pregnancy outcomes. PMID:25433396

  19. Exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs) and polybrominated diphenyl ethers (PBDEs) through the consumption of prepared meals in Italy.

    PubMed

    De Filippis, Stefania P; Brambilla, Gianfranco; Dellatte, Elena; Corrado, Federica; Esposito, Mauro

    2014-01-01

    Diet is a relevant source of exposure to environmental pollutants. Dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs) and polybrominated diphenyl ethers (PBDEs) by the Italian population was assessed through a duplicate diet study on prepared meals. Baby food composite representative of the diet of toddlers aged 9-12 months and school canteen servings from four towns in Italy representing the diet of children aged 4-9 years were collected on a 5-day basis. Similarly, 5-day lunches from an office canteen, 7-day lunches from a hotel-school, three fast food meals, and eight duplicate 1-day meals of individuals (one vegetarian) were selected to represent the diet of adults aged above 18 years. Servings from each diet were then pooled to form a composite and analysed. Dietary intake was estimated from the resulting contaminant levels in composites combined with age-related food consumption data from national survey. The mean upper bound (UB) intakes for cumulative PCDDs, PCDFs, and DL-PCBs were 0.67, 0.63-0.92, and 0.27-0.63 pg WHO2005-TE kg(-1) body weight (bw) day(-1) for toddlers, children and adults, respectively. BDE-47 (UB) ng kg(-1) bw day(-1) estimates were 2.75 in toddlers, 0.08-0.16 in children and 0.03-0.09 in adults. Similarly, for BDE-99 higher UB intakes (ng kg(-1) bw day(-1)) resulted in toddlers (1.26), than those in children (0.06-0.08) and adults (0.03-0.10), respectively. The above estimates fall below the tolerable weekly intake (TWI) (14 WHO2005-TE kg(-1) bw day(-1)) established by the European Union Scientific Committee on Food (SCF) for PCDD/Fs and DL-PCBs. The margin of exposure (MOE = 3) of toddlers to BDE-99 clearly indicates this age group as target for a risk-oriented approach. This study is proposed as a first cost-effective screening in PCDD, PCDF, DL-PCB and PBDE intake assessment, with a focus also on time trends. PMID:24645918

  20. Exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs) and polybrominated diphenyl ethers (PBDEs) through the consumption of prepared meals in Italy.

    PubMed

    De Filippis, Stefania P; Brambilla, Gianfranco; Dellatte, Elena; Corrado, Federica; Esposito, Mauro

    2014-01-01

    Diet is a relevant source of exposure to environmental pollutants. Dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs) and polybrominated diphenyl ethers (PBDEs) by the Italian population was assessed through a duplicate diet study on prepared meals. Baby food composite representative of the diet of toddlers aged 9-12 months and school canteen servings from four towns in Italy representing the diet of children aged 4-9 years were collected on a 5-day basis. Similarly, 5-day lunches from an office canteen, 7-day lunches from a hotel-school, three fast food meals, and eight duplicate 1-day meals of individuals (one vegetarian) were selected to represent the diet of adults aged above 18 years. Servings from each diet were then pooled to form a composite and analysed. Dietary intake was estimated from the resulting contaminant levels in composites combined with age-related food consumption data from national survey. The mean upper bound (UB) intakes for cumulative PCDDs, PCDFs, and DL-PCBs were 0.67, 0.63-0.92, and 0.27-0.63 pg WHO2005-TE kg(-1) body weight (bw) day(-1) for toddlers, children and adults, respectively. BDE-47 (UB) ng kg(-1) bw day(-1) estimates were 2.75 in toddlers, 0.08-0.16 in children and 0.03-0.09 in adults. Similarly, for BDE-99 higher UB intakes (ng kg(-1) bw day(-1)) resulted in toddlers (1.26), than those in children (0.06-0.08) and adults (0.03-0.10), respectively. The above estimates fall below the tolerable weekly intake (TWI) (14 WHO2005-TE kg(-1) bw day(-1)) established by the European Union Scientific Committee on Food (SCF) for PCDD/Fs and DL-PCBs. The margin of exposure (MOE = 3) of toddlers to BDE-99 clearly indicates this age group as target for a risk-oriented approach. This study is proposed as a first cost-effective screening in PCDD, PCDF, DL-PCB and PBDE intake assessment, with a focus also on time trends.

  1. Relationships between dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like biphenyls (dl-PCBs) congener concentrations in aquatic organisms from Sydney Estuary, Australia and physiology, spatial, seasonality, trophodynamic and life history traits.

    PubMed

    Sezmis, Aysha Laila; Birch, Gavin; Covaci, Adrian

    2014-08-15

    Over the past few decades, there has been considerable interest in hydrophobic persistent organic pollutants (POPs) and their accumulative properties in aquatic organisms. Several factors, such as environmental concentrations (i.e. in sediment) and physiological characteristics of organisms determine species-specific accumulation patterns of POPs in marine animal tissue. The present study investigated factors that govern species-specific accumulation patterns of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like biphenyls (dl-PCBs) in a food web from Sydney Estuary (Australia). The results indicated that physiological characteristics, i.e. lipid %, spatial, i.e. distance from Homebush Bay (point source of POPs) and life history characteristics of the organisms, such as diet and home range, influence PCDD/F and dl-PCB tissue concentrations to a varying degree. For example, PCDD/F tissue concentrations increased with the presence of detritivorous diet, species with limited home range and close proximity to Homebush Bay. On the other hand, lipid %, piscivorous diet and close proximity to Homebush Bay were the main predictors causing increases in dl-PCB tissue levels. Distance from Homebush Bay was the only predictor affecting both PCDD/F and dl-PCB tissue levels at a similar rate, i.e. decreasing tissue concentrations as the distance increases from Homebush Bay.

  2. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    SciTech Connect

    Nelson, O.D.

    1997-09-04

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage.

  3. Portable exhauster POR-007/Skid E and POR-008/Skid F storage plan

    SciTech Connect

    Nelson, O.D.

    1998-07-25

    This document provides storage requirements for 1,000 CFM portable exhausters POR-O07/Skid E and POR-008/Skid F. These requirements are presented in three parts: preparation for storage, storage maintenance and testing, and retrieval from storage. The exhauster component identification numbers listed in this document contain the prefix POR-007 or POR-008 depending on which exhauster is being used.

  4. Consequences of POR mutations and polymorphisms

    PubMed Central

    Miller, Walter L.; Agrawal, Vishal; Sandee, Duanpen; Tee, Meng Kian; Huang, Ningwu; Choi, Ji Ha; Morrissey, Kari; Giacomini, Kathleen M.

    2015-01-01

    P450 oxidoreductase (POR) transports electrons from NADPH to all microsomal cytochrome P450 enzymes, including steroidogenic P450c17, P450c21 and P450aro. Severe POR mutations A287P (in Europeans) and R457H (in Japanese) cause the Antley-Bixler skeletal malformation syndrome (ABS) plus impaired steroidogenesis (causing genital anomalies), but the basis of ABS is unclear. We have characterized the activities of ~40 POR variants, showing that assays based on P450c17 activities, but not cytochrome c assays, correlate with the clinical phenotype. The human POR gene is highly polymorphic: the A503V sequence variant, which decreases P450c17 activities to ~60%, is found on ~28% of human alleles. A promoter polymorphism (~8% of Asians and ~13% of Caucasians) at −152 reduces transcriptional activity by half. Screening of 35 POR variants showed that most mutants lacking activity with P450c17 or cytochrome c also lacked activity to support CYP1A2 and CYP2C19 metabolism of EOMCC (a fluorogenic non-drug substrate), although there were some remarkable differences: Q153R causes ABS and has ~30% of wild-type activity with P450c17 but had 144% of WT activity with CYP1A2 and 284% with CYP2C19. The effects of POR variants on CYP3A4, which metabolizes nearly 50% of clinically used drugs, was examined with multiple, clinically-relevant drug substrates, showing that A287P and R457H dramatically reduce drug metabolism, and that A503V variably impairs drug metabolism. The degree of activity can vary with the drug substrate assayed, as the drugs can influence the conformation of the P450. POR is probably an important contributor to genetic variation in both steroidogenesis and drug metabolism. PMID:21070833

  5. Desigualdades por cáncer

    Cancer.gov

    Información básica de las desigualdades en salud por cáncer en EE. UU., factores que contribuyen a la carga desproporcionada del cáncer en algunos grupos y ejemplos de desigualdades en incidencia y mortalidad entre ciertos grupos de la población.

  6. Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System

    PubMed Central

    Gorasia, Dhana G.; Veith, Paul D.; Hanssen, Eric G.; Glew, Michelle D.; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C.

    2016-01-01

    The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32–36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component. PMID:27509186

  7. Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

    PubMed

    Gorasia, Dhana G; Veith, Paul D; Hanssen, Eric G; Glew, Michelle D; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C

    2016-08-01

    The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component. PMID:27509186

  8. Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

    PubMed

    Gorasia, Dhana G; Veith, Paul D; Hanssen, Eric G; Glew, Michelle D; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C

    2016-08-01

    The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component.

  9. The PorX Response Regulator of the Porphyromonas gingivalis PorXY Two-Component System Does Not Directly Regulate the Type IX Secretion Genes but Binds the PorL Subunit

    PubMed Central

    Vincent, Maxence S.; Durand, Eric; Cascales, Eric

    2016-01-01

    The Type IX secretion system (T9SS) is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion or cell surface exposition of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the oral pathogen Porphyromonas gingivalis have been identified based on genome substractive analyses. Among these proteins, PorY, and PorX encode typical two-component system (TCS) sensor and CheY-like response regulator respectively. Although the porX and porY genes do not localize at the same genetic locus, it has been proposed that PorXY form a bona fide TCS. Deletion of porX in P. gingivalis causes a slight decrease of the expression of a number of other T9SS genes, including sov, porT, porP, porK, porL, porM, porN, and porY. Here, we show that PorX and the soluble cytoplasmic domain of PorY interact. Using electrophoretic mobility shift, DNA-protein co-purification and heterologous host expression assays, we demonstrate that PorX does not bind T9SS gene promoters and does not directly regulate expression of the T9SS genes. Finally, we show that PorX interacts with the cytoplasmic domain of PorL, a component of the T9SS membrane core complex and propose that the CheY-like PorX protein might be involved in the dynamics of the T9SS. PMID:27630829

  10. The PorX Response Regulator of the Porphyromonas gingivalis PorXY Two-Component System Does Not Directly Regulate the Type IX Secretion Genes but Binds the PorL Subunit.

    PubMed

    Vincent, Maxence S; Durand, Eric; Cascales, Eric

    2016-01-01

    The Type IX secretion system (T9SS) is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion or cell surface exposition of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the oral pathogen Porphyromonas gingivalis have been identified based on genome substractive analyses. Among these proteins, PorY, and PorX encode typical two-component system (TCS) sensor and CheY-like response regulator respectively. Although the porX and porY genes do not localize at the same genetic locus, it has been proposed that PorXY form a bona fide TCS. Deletion of porX in P. gingivalis causes a slight decrease of the expression of a number of other T9SS genes, including sov, porT, porP, porK, porL, porM, porN, and porY. Here, we show that PorX and the soluble cytoplasmic domain of PorY interact. Using electrophoretic mobility shift, DNA-protein co-purification and heterologous host expression assays, we demonstrate that PorX does not bind T9SS gene promoters and does not directly regulate expression of the T9SS genes. Finally, we show that PorX interacts with the cytoplasmic domain of PorL, a component of the T9SS membrane core complex and propose that the CheY-like PorX protein might be involved in the dynamics of the T9SS. PMID:27630829

  11. The PorX Response Regulator of the Porphyromonas gingivalis PorXY Two-Component System Does Not Directly Regulate the Type IX Secretion Genes but Binds the PorL Subunit.

    PubMed

    Vincent, Maxence S; Durand, Eric; Cascales, Eric

    2016-01-01

    The Type IX secretion system (T9SS) is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion or cell surface exposition of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the oral pathogen Porphyromonas gingivalis have been identified based on genome substractive analyses. Among these proteins, PorY, and PorX encode typical two-component system (TCS) sensor and CheY-like response regulator respectively. Although the porX and porY genes do not localize at the same genetic locus, it has been proposed that PorXY form a bona fide TCS. Deletion of porX in P. gingivalis causes a slight decrease of the expression of a number of other T9SS genes, including sov, porT, porP, porK, porL, porM, porN, and porY. Here, we show that PorX and the soluble cytoplasmic domain of PorY interact. Using electrophoretic mobility shift, DNA-protein co-purification and heterologous host expression assays, we demonstrate that PorX does not bind T9SS gene promoters and does not directly regulate expression of the T9SS genes. Finally, we show that PorX interacts with the cytoplasmic domain of PorL, a component of the T9SS membrane core complex and propose that the CheY-like PorX protein might be involved in the dynamics of the T9SS.

  12. The PorX Response Regulator of the Porphyromonas gingivalis PorXY Two-Component System Does Not Directly Regulate the Type IX Secretion Genes but Binds the PorL Subunit

    PubMed Central

    Vincent, Maxence S.; Durand, Eric; Cascales, Eric

    2016-01-01

    The Type IX secretion system (T9SS) is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion or cell surface exposition of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the oral pathogen Porphyromonas gingivalis have been identified based on genome substractive analyses. Among these proteins, PorY, and PorX encode typical two-component system (TCS) sensor and CheY-like response regulator respectively. Although the porX and porY genes do not localize at the same genetic locus, it has been proposed that PorXY form a bona fide TCS. Deletion of porX in P. gingivalis causes a slight decrease of the expression of a number of other T9SS genes, including sov, porT, porP, porK, porL, porM, porN, and porY. Here, we show that PorX and the soluble cytoplasmic domain of PorY interact. Using electrophoretic mobility shift, DNA-protein co-purification and heterologous host expression assays, we demonstrate that PorX does not bind T9SS gene promoters and does not directly regulate expression of the T9SS genes. Finally, we show that PorX interacts with the cytoplasmic domain of PorL, a component of the T9SS membrane core complex and propose that the CheY-like PorX protein might be involved in the dynamics of the T9SS.

  13. System design description for portable 1,000 CFM exhauster Skids POR-007/Skid E and POR-008/Skid F

    SciTech Connect

    Nelson, O.D.

    1998-07-25

    The primary purpose of the two 1,000 CFM Exhauster Skids, POR-007-SKID E and POR-008-SKID F, is to provide backup to the waste tank primary ventilation systems for tanks 241-C-106 and 241-AY-102, and the AY-102 annulus in the event of a failure during the sluicing of tank 241-C-106 and subsequent transfer of sluiced waste to 241-AY-102. This redundancy is required since both of the tank ventilation systems have been declared as Safety Class systems.

  14. Identification of Porphyromonas gingivalis proteins secreted by the Por secretion system.

    PubMed

    Sato, Keiko; Yukitake, Hideharu; Narita, Yuka; Shoji, Mikio; Naito, Mariko; Nakayama, Koji

    2013-01-01

    The Gram-negative bacterium Porphyromonas gingivalis possesses a number of potential virulence factors for periodontopathogenicity. In particular, cysteine proteinases named gingipains are of interest given their abilities to degrade host proteins and process other virulence factors such as fimbriae. Gingipains are translocated on the cell surface or into the extracellular milieu by the Por secretion system (PorSS), which consists of a number of membrane or periplasmic proteins including PorK, PorL, PorM, PorN, PorO, PorP, PorQ, PorT, PorU, PorV (PG27, LptO), PorW and Sov. To identify proteins other than gingipains secreted by the PorSS, we compared the proteomes of P. gingivalis strains kgp rgpA rgpB (PorSS-proficient strain) and kgp rgpA rgpB porK (PorSS-deficient strain) using two-dimensional gel electrophoresis and peptide-mass fingerprinting. Sixteen spots representing 10 different proteins were present in the particle-free culture supernatant of the PorSS-proficient strain but were absent or faint in that of the PorSS-deficient strain. These identified proteins possessed the C-terminal domains (CTDs), which had been suggested to form the CTD protein family. These results indicate that the PorSS is used for secretion of a number of proteins other than gingipains and that the CTDs of the proteins are associated with the PorSS-dependent secretion. PMID:23075153

  15. Identification of Porphyromonas gingivalis proteins secreted by the Por secretion system.

    PubMed

    Sato, Keiko; Yukitake, Hideharu; Narita, Yuka; Shoji, Mikio; Naito, Mariko; Nakayama, Koji

    2013-01-01

    The Gram-negative bacterium Porphyromonas gingivalis possesses a number of potential virulence factors for periodontopathogenicity. In particular, cysteine proteinases named gingipains are of interest given their abilities to degrade host proteins and process other virulence factors such as fimbriae. Gingipains are translocated on the cell surface or into the extracellular milieu by the Por secretion system (PorSS), which consists of a number of membrane or periplasmic proteins including PorK, PorL, PorM, PorN, PorO, PorP, PorQ, PorT, PorU, PorV (PG27, LptO), PorW and Sov. To identify proteins other than gingipains secreted by the PorSS, we compared the proteomes of P. gingivalis strains kgp rgpA rgpB (PorSS-proficient strain) and kgp rgpA rgpB porK (PorSS-deficient strain) using two-dimensional gel electrophoresis and peptide-mass fingerprinting. Sixteen spots representing 10 different proteins were present in the particle-free culture supernatant of the PorSS-proficient strain but were absent or faint in that of the PorSS-deficient strain. These identified proteins possessed the C-terminal domains (CTDs), which had been suggested to form the CTD protein family. These results indicate that the PorSS is used for secretion of a number of proteins other than gingipains and that the CTDs of the proteins are associated with the PorSS-dependent secretion.

  16. Disminuyen en los Estados Unidos las infecciones por VPH.

    Cancer.gov

    La infección por los tipos del virus del papiloma humano (VPH) en el blanco de la vacuna cuadrivalente se redujo en casi dos tercios en las adolescentes desde que se recomendó la vacunación en los Estados Unidos.

  17. Centros oncológicos designados por el NCI

    Cancer.gov

    El programa de centros oncológicos designados por el Instituto Nacional del Cáncer (NCI) reconoce a los centros de todo el país que cumplen con rigurosos criterios para participar en proyectos avanzados de primer nivel para la investigación multidisciplinaria del cáncer.

  18. Se evitaron casi 800 000 muertes por descenso del tabaquismo

    Cancer.gov

    Programas y estrategias de control del tabaco del siglo XX fueron responsables de la prevención de más de 795 000 muertes por cáncer de pulmón en Estados Unidos de 1975 al 2000. Si todo el tabaquismo en este país hubiera cesado después de la publicación d

  19. Neisseria meningitidis Lacking the Major Porins PorA and PorB Is Viable and Modulates Apoptosis and the Oxidative Burst of Neutrophils.

    PubMed

    Peak, Ian R; Chen, Adrienne; Jen, Freda E-C; Jennings, Courtney; Schulz, Benjamin L; Saunders, Nigel J; Khan, Arshad; Seifert, H Steven; Jennings, Michael P

    2016-08-01

    The bacterial pathogen Neisseria meningitidis expresses two major outer-membrane porins. PorA expression is subject to phase-variation (high frequency, random, on-off switching), and both PorA and PorB are antigenically variable between strains. PorA expression is variable and not correlated with meningococcal colonisation or invasive disease, whereas all naturally-occurring strains express PorB suggesting strong selection for expression. We have generated N. meningitidis strains lacking expression of both major porins, demonstrating that they are dispensable for bacterial growth in vitro. The porAB mutant strain has an exponential growth rate similar to the parental strain, as do the single porA or porB mutants, but the porAB mutant strain does not reach the same cell density in stationary phase. Proteomic analysis suggests that the double mutant strain exhibits compensatory expression changes in proteins associated with cellular redox state, energy/nutrient metabolism, and membrane stability. On solid media, there is obvious growth impairment that is rescued by addition of blood or serum from mammalian species, particularly heme. These porin mutants are not impaired in their capacity to inhibit both staurosporine-induced apoptosis and a phorbol 12-myristate 13-acetate-induced oxidative burst in human neutrophils suggesting that the porins are not the only bacterial factors that can modulate these processes in host cells.

  20. Compton imaging with the PorGamRays spectrometer

    NASA Astrophysics Data System (ADS)

    Judson, D. S.; Boston, A. J.; Coleman-Smith, P. J.; Cullen, D. M.; Hardie, A.; Harkness, L. J.; Jones, L. L.; Jones, M.; Lazarus, I.; Nolan, P. J.; Pucknell, V.; Rigby, S. V.; Seller, P.; Scraggs, D. P.; Simpson, J.; Slee, M.; Sweeney, A.; PorGamRays Collaboration

    2011-10-01

    The PorGamRays project aims to develop a portable gamma-ray detection system with both spectroscopic and imaging capabilities. The system is designed around a stack of thin Cadmium Zinc Telluride (CZT) detectors. The imaging capability utilises the Compton camera principle. Each detector is segmented into 100 pixels which are read out through custom designed Application Specific Integrated Circuits (ASICs). This device has potential applications in the security, decommissioning and medical fields. This work focuses on the near-field imaging performance of a lab-based demonstrator consisting of two pixelated CZT detectors, each of which is bonded to a NUCAM II ASIC. Measurements have been made with point 133Ba and 57Co sources located ˜35 mm from the surface of the scattering detector. Position resolution of ˜20 mm FWHM in the x and y planes is demonstrated.

  1. Acceptance test report for portable exhauster POR-007/Skid E

    SciTech Connect

    Kriskovich, J.R.

    1998-07-24

    This document describes Acceptance Testing performed on Portable Exhauster POR-007/Skid E. It includes measurements of bearing vibration levels, pressure decay testing, programmable logic controller interlocks, high vacuum, flow and pressure control functional testing. The purpose of Acceptance testing documented by this report was to demonstrate compliance of the exhausters with the performance criteria established within HNF-0490, Rev. 1 following a repair and upgrade effort at Hanford. In addition, data obtained during this testing is required for the resolution of outstanding Non-conformance Reports (NCR), and finally, to demonstrate the functionality of the associated software for the pressure control and high vacuum exhauster operating modes provided for by W-320. Additional testing not required by the ATP was also performed to assist in the disposition and close out of receiving inspection report and for application design information (system curve). Results of this testing are also captured within this document.

  2. Typing and surface charges of the variable loop regions of PorB from Neisseria meningitidis.

    PubMed

    Stefanelli, Paola; Neri, Arianna; Tanabe, Mikio; Fazio, Cecilia; Massari, Paola

    2016-06-01

    PorB is a pan-Neisserial major outer membrane protein with a trimeric β-barrel structure. Each monomer presents eight periplasmic turns and eight surface exposed loop regions with sequence variability. PorB induces activation of host cell responses via a TLR2-dependent mechanism likely mediated by electrostatic interactions between TLR2 and PorB surface exposed loops. Variability in the loop amino acid sequence is known to influence cell responses to PorB in vitro, particularly for the residues in L5 and L7. In this work, the sequence of the porB gene and the electrostatic surface charges of PorB from 35 invasive meningococcal isolates belonging to the main clonal complexes identified in Italy and from five carriage genomes available on the website http://pubmlst.org/neisseria/ were examined. Analysis of the porB encoding regions from the invasive meningococci has identified four new alleles and a potential association between porB alleles, serogroup, and clonal complexes. Through computer-based modeling and analysis of the electrostatic surface charges of PorB from these strains, loop charge segregation between PorB from invasive serogroups B and C was observed. Specifically, loops 1, 4, and 7 were negatively charged and L2 and L8 were mostly neutral in serogroup B isolates, while an overall homogeneous positive surface charge was present in PorB from invasive serogroup C strains. A higher PorB sequence variability was observed among carriage genomes, and a general prevalence of negative loop surface charges. The surface charge differences in PorB from serogroups B and C invasive and carriage strains may, in part, influence the outcomes of Neisseriae interactions with host cells. © 2016 IUBMB Life, 68(6):488-495, 2016. PMID:27156582

  3. Typing and surface charges of the variable loop regions of PorB from Neisseria meningitidis.

    PubMed

    Stefanelli, Paola; Neri, Arianna; Tanabe, Mikio; Fazio, Cecilia; Massari, Paola

    2016-06-01

    PorB is a pan-Neisserial major outer membrane protein with a trimeric β-barrel structure. Each monomer presents eight periplasmic turns and eight surface exposed loop regions with sequence variability. PorB induces activation of host cell responses via a TLR2-dependent mechanism likely mediated by electrostatic interactions between TLR2 and PorB surface exposed loops. Variability in the loop amino acid sequence is known to influence cell responses to PorB in vitro, particularly for the residues in L5 and L7. In this work, the sequence of the porB gene and the electrostatic surface charges of PorB from 35 invasive meningococcal isolates belonging to the main clonal complexes identified in Italy and from five carriage genomes available on the website http://pubmlst.org/neisseria/ were examined. Analysis of the porB encoding regions from the invasive meningococci has identified four new alleles and a potential association between porB alleles, serogroup, and clonal complexes. Through computer-based modeling and analysis of the electrostatic surface charges of PorB from these strains, loop charge segregation between PorB from invasive serogroups B and C was observed. Specifically, loops 1, 4, and 7 were negatively charged and L2 and L8 were mostly neutral in serogroup B isolates, while an overall homogeneous positive surface charge was present in PorB from invasive serogroup C strains. A higher PorB sequence variability was observed among carriage genomes, and a general prevalence of negative loop surface charges. The surface charge differences in PorB from serogroups B and C invasive and carriage strains may, in part, influence the outcomes of Neisseriae interactions with host cells. © 2016 IUBMB Life, 68(6):488-495, 2016.

  4. Concentrations of PCDD/PCDFs and PCBs in spent foundry sands.

    PubMed

    Dungan, Robert S; Huwe, Janice; Chaney, Rufus L

    2009-05-01

    Approximately 10 million tons of spent foundry sand (SFS) are generated in the United States each year, and their beneficial use in agricultural and horticultural applications is being considered. Other studies have demonstrated that trace elements are low enough in sands from iron, steel, and aluminum foundries to allow their beneficial use. Because data were not available on polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in SFSs, we analyzed representative spent sands from 10 foundries to assess the potential for these compounds to limit their use in soil-related applications. The total TEQ (toxicity equivalent) concentrations ranged from 0.01 to 3.13 ng TEQ kg(-1), with an average concentration of 0.58 ng TEQ kg(-1). These concentrations are within the range of natural background in soils. PMID:19264346

  5. Magnification and toxicity of PCBs, PCDDs, and PCDFs in upriver-migrating Pacific salmon.

    PubMed

    Debruyn, Adrian M H; Ikonomou, Michael G; Gobas, Frank A P C

    2004-12-01

    The depletion of lipids associated with pre-spawning migration of Pacific salmon has the potential to magnify concentrations of hydrophobic organic contaminants (HOCs), which elevates risk of toxic effects. We present data from a field study of sockeye salmon (Oncorhynchus nerka) migrating to spawn in Great Central Lake, BC, which demonstrate that pre-spawning migration causes a magnification of PCB, PCDD, and PCDF concentrations in female gonads (1.9-2.5-fold), female soma (3.4-5.6-fold), and male soma (5.6-9.7-fold). We further develop a model of prespawning migration chemical magnification for sockeye salmon stocks as a function of migration distance. This model is shown to be consistent with available empirical data on pre-spawning magnification and predicts magnification factors ranging between 1.4 and 7.9 in gonad and between 1.6 and 10.4 in soma in seven Pacific salmon stocks in British Columbia. Post-migration (prespawning) toxic equivalent dioxin concentrations in roe were measured to be approximately 3 pg/g lipid in salmon from the Great Central Lake sockeye stock and estimated to range between 1.5 pg/g lipid for the shortest-migrating stocks and 7 pg/g lipid for the longest-migrating stocks. Concentrations in certain stocks approach or exceed the concentration of 3 pg/g lipid associated with 30% egg mortality in Oncorhynchus mykiss. This indicates the potential for population-level effects of current contaminant levels. It also suggests that historic contaminant concentrations, which were greater than current concentrations, may have contributed significantly to the decline of certain Pacific salmon stocks in British Columbia.

  6. Concentrations of PCDD/PCDFs and PCBs in spent foundry sands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately 10 million tons of spent foundry sand (SFS) are generated in the U.S. each year, and their beneficial use in agricultural and horticultural applications is being considered. Other studies have demonstrated that trace elements are low enough in sands from iron, steel, and aluminum foun...

  7. PCDDs, PCDFs and PCBs in farmed fish produced in Greece: Levels and human population exposure assessment.

    PubMed

    Costopoulou, Danae; Vassiliadou, Irene; Leondiadis, Leondios

    2016-03-01

    Fish is among the essential components of Mediterranean diet and has beneficial effects on human health. Farmed fish is an affordable alternative to wild fish and a significant food export product for Greece. Published studies worldwide have reported significant levels of environmental pollutants in fish tissues. Especially for PCDDs/Fs and PCBs, the studies suggest that the most important contribution to human dietary intake is from fish and seafood. In the present study, we investigate the levels of PCDDs/Fs, dioxin-like and non dioxin-like PCBs in the most common farmed fish species produced in Greece i.e. sea bass, sea bream and rainbow trout. These species are widely consumed in Greece and are also exported to many countries worldwide. The mean levels found were WHO-PCDD/F-TEQ: 0.22 pg g(-1) wet weight (w.w.), WHO-PCDD/F-PCB-TEQ: 0.88 pg g(-1) w.w. for sea bream, WHO-PCDD/F-TEQ: 0.13 pg g(-1) w.w., WHO-PCDD/F-PCB-TEQ: 0.68 pg g(-1) w.w. for sea bass and WHO-PCDD/F-TEQ: 0.10 pg g(-1) w.w., WHO-PCDD/F-PCB-TEQ: 0.43 pg g(-1) w.w. for rainbow trout. For non dioxin-like PCBs, mean sum values found were 8.02 ng g(-1) w.w. for sea bream, 5.24 ng g(-1) w.w. for sea bass and 2.90 ng g(-1) w.w. for rainbow trout. All concentrations found were far below maximum levels set by the European Union and in the same range as wild-caught fish also presented for comparison. Daily intake from the consumption of farmed fish species examined is calculated at 1.3 pg WHO-TEQ kg(-1) b.w., which is at the lowest end of TDI values proposed by the WHO.

  8. Reduced birthweight and length in the offspring of females exposed to PCDFs, PCP, and lindane.

    PubMed Central

    Karmaus, W; Wolf, N

    1995-01-01

    The objective of this study was to investigate a broad range of adverse health outcomes and their potential association to wood preservative used in daycare centers. This article focuses on reproductive effects. A sample of 221 exposed teachers was provided by the employer's liability insurers. A comparison group (n = 189) insured by the same two organizations was recruited from nonexposed daycare centers. In a face-to-face interview, job history and reproductive history of 398 female teachers were ascertained. Data on exposure were provided, including measurements on concentration of pentachlorophenol (PCP) and lindane in wood panels, and of PCP, lindane, polychlorinated dibenzo-p-dioxins and dibenzofurans in indoor air. An exposure matrix based on individual job history, independent exposure information from each center, and reproductive history was set up with regard to the vulnerable time windows for each pregnancy. Using this approach, 49 exposed and 507 nonexposed pregnancies were identified, including 32 exposed and 386 nonexposed live births. For subgroup analyses the observations were restricted to independent pregnancies, excluding multiple and consecutive births. The data were analyzed with linear regression techniques, taking confounders into account. The crude median difference between exposed and nonexposed was 175 g in birthweight and 2 cm in length. Controlling for confounders, the results show a significantly reduced but weight (p = 0.04) and length (p = 0.02) in exposed pregnancies, even after restricting the data to independent pregnancies and pregnancies for which data could be validated from the mother's health cards. These differences were not explained by differences in gestational age indicating that a toxic effect, which could cause small-for date newborns, might have affected the fetus. Images Figure 1. Figure 2. Figure 3. PMID:8747018

  9. Validation of emission test method for PCDs and PCDFs: Work assignment No. 23. Final report

    SciTech Connect

    Coates, J.T.

    1990-03-01

    The precision and accuracy of the Modified Method Five (MM5) sampling and analysis scheme for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) in municipal waste combustor stack gas have been determined. This was accomplished using a dynamic spiking system designed to continuously deliver stable isotopic PCDD/PCDF congeners into the MM5 sampling train upstream of the particulate filter during sampling of incinerator stack gas. Field validation tests to measure the recovery of statically and dynamically spiked PCDD/PCDF during stack gas sampling indicated that the resin effectively retained the static spike during operating conditions. Dynamic spike recoveries were inadequate, partially due to the use of dichloromethane as the extraction solvent. Toluene was subsequently shown to be more appropriate than dichloromethane for obtaining enhanced recoveries of PCDD/PCDF. The overall sampling and analysis scheme as recommended in the report was estimated as at better than 80% for the accuracy and as at + or - 35% for the precision.

  10. Evaluation of the measurement uncertainty in automated long-term sampling of PCDD/PCDFs.

    PubMed

    Vicaretti, M; D'Emilia, G; Mosca, S; Guerriero, E; Rotatori, M

    2013-12-01

    Since the publication of the first version of European standard EN-1948 in 1996, long-term sampling equipment has been improved to a high standard for the sampling and analysis of polychlorodibenzo-p-dioxin (PCDD)/polychlorodibenzofuran (PCDF) emissions from industrial sources. The current automated PCDD/PCDF sampling systems enable to extend the measurement time from 6-8 h to 15-30 days in order to have data values better representative of the real pollutant emission of the plant in the long period. EN-1948:2006 is still the European technical reference standard for the determination of PCDD/PCDF from stationary source emissions. In this paper, a methodology to estimate the measurement uncertainty of long-term automated sampling is presented. The methodology has been tested on a set of high concentration sampling data resulting from a specific experience; it is proposed with the intent that it is to be applied on further similar studies and generalized. A comparison between short-term sampling data resulting from manual and automated parallel measurements has been considered also in order to verify the feasibility and usefulness of automated systems and to establish correlations between results of the two methods to use a manual method for calibration of automatic long-term one. The uncertainty components of the manual method are analyzed, following the requirements of EN-1948-3:2006, allowing to have a preliminary evaluation of the corresponding uncertainty components of the automated system. Then, a comparison between experimental data coming from parallel sampling campaigns carried out in short- and long-term sampling periods is realized. Long-term sampling is more reliable to monitor PCDD/PCDF emissions than occasional short-term sampling. Automated sampling systems can assure very useful emission data both in short and long sampling periods. Despite this, due to the different application of the long-term sampling systems, the automated results could not be directly compared with manual results, not even in terms of measurement uncertainty. This investigation focuses on both uncertainty and repeatability of the automated sampling method. The standard 20988, developed by Internarional Organization of Standardization (ISO) can be used to estimate the measurement uncertainty. The results confirm that the uncertainties of manual and automated methods are comparable. At the same time, it is not appropriate to consider the manual method as a reference for the evaluation of the uncertainty of the automated sampling system, due to the high variability of both systems.

  11. VDAC and the bacterial porin PorB of Neisseria gonorrhoeae share mitochondrial import pathways.

    PubMed

    Müller, Anne; Rassow, Joachim; Grimm, Jan; Machuy, Nikolaus; Meyer, Thomas F; Rudel, Thomas

    2002-04-15

    The human pathogen Neisseria gonorrhoeae induces host cell apoptosis during infection by delivering the outer membrane protein PorB to the host cell's mitochondria. PorB is a pore-forming beta-barrel protein sharing several features with the mitochondrial voltage-dependent anion channel (VDAC), which is involved in the regulation of apoptosis. Here we show that PorB of pathogenic Neisseria species produced by host cells is efficiently targeted to mitochondria. Imported PorB resides in the mitochondrial outer membrane and forms multimers with similar sizes as in the outer bacterial membrane. The mitochondria completely lose their membrane potential, a characteristic previously observed in cells infected with gonococci or treated with purified PorB. Closely related bacterial porins of non-pathogenic Neisseria mucosa or Escherichia coli remain in the cytosol. Import of PorB into mitochondria in vivo is independent of a linear signal sequence. Insertion of PorB into the mitochondrial outer membrane in vitro depends on the activity of Tom5, Tom20 and Tom40, but is independent of Tom70. Our data show that human VDAC and bacterial PorB are imported into mitochondria by a similar mechanism. PMID:11953311

  12. P450 (Cytochrome) Oxidoreductase Gene (POR) Common Variant (POR*28) Significantly Alters CYP2C9 Activity in Swedish, But Not in Korean Healthy Subjects.

    PubMed

    Hatta, Fazleen H M; Aklillu, Eleni

    2015-12-01

    CYP2C9 enzyme contributes to the metabolism of several pharmaceuticals and xenobiotics and yet displays large person-to-person and interethnic variation. Understanding the mechanisms of CYP2C9 variation is thus of immense importance for personalized medicine and rational therapeutics. A genetic variant of P450 (cytochrome) oxidoreductase (POR), a CYP450 redox partner, is reported to influence CYP2C9 metabolic activity in vitro. We investigated the impact of a common variant, POR*28, on CYP2C9 metabolic activity in humans. 148 healthy Swedish and 146 healthy Korean volunteers were genotyped for known CYP2C9 defective variant alleles (CYP2C9*2, *3). The CYP2C9 phenotype was determined using a single oral dose of 50 mg losartan. Excluding oral contraceptive (OC) users and carriers of 2C9*2 and *3 alleles, 117 Korean and 65 Swedish were genotyped for POR*5, *13 and *28 using Taqman assays. The urinary losartan to its metabolite E-3174 metabolic ratio (MR) was used as an index of CYP2C9 metabolic activity. The allele frequency of the POR*28 variant allele in Swedes and Koreans was 29% and 44%, respectively. POR*5 and *13 were absent in both study populations. Considering the CYP2C9*1/*1 genotypes only, the CYP2C9 metabolic activity was 1.40-fold higher in carriers of POR*28 allele than non-carriers among Swedes (p = 0.02). By contrast, no influence of the POR*28 on CYP2C9 activity was found in Koreans (p = 0.68). The multivariate analysis showed that ethnicity, POR genotype, and smoking were strong predictors of CYP2C9 MR (p < 0.05). This is the first report to implicate the importance of POR*28 genetic variation for CYP2C9 metabolic activity in humans. These findings contribute to current efforts for global personalized medicine and using medicines by taking into account pharmacogenetic and phenotypic variations. PMID:26669712

  13. Genome Sequences of Pseudomonas oryzihabitans Phage POR1 and Pseudomonas aeruginosa Phage PAE1

    PubMed Central

    Dyson, Zoe A.; Seviour, Robert J.; Tucci, Joseph

    2016-01-01

    We report the genome sequences of two double-stranded DNA siphoviruses, POR1 infective for Pseudomonas oryzihabitans and PAE1 infective for Pseudomonas aeruginosa. The phage POR1 genome showed no nucleotide sequence homology to any other DNA phage sequence in the GenBank database, while phage PAE1 displayed synteny to P. aeruginosa phages M6, MP1412, and YuA. PMID:27313312

  14. Genome Sequences of Pseudomonas oryzihabitans Phage POR1 and Pseudomonas aeruginosa Phage PAE1.

    PubMed

    Dyson, Zoe A; Seviour, Robert J; Tucci, Joseph; Petrovski, Steve

    2016-06-16

    We report the genome sequences of two double-stranded DNA siphoviruses, POR1 infective for Pseudomonas oryzihabitans and PAE1 infective for Pseudomonas aeruginosa The phage POR1 genome showed no nucleotide sequence homology to any other DNA phage sequence in the GenBank database, while phage PAE1 displayed synteny to P. aeruginosa phages M6, MP1412, and YuA.

  15. Genome Sequences of Pseudomonas oryzihabitans Phage POR1 and Pseudomonas aeruginosa Phage PAE1.

    PubMed

    Dyson, Zoe A; Seviour, Robert J; Tucci, Joseph; Petrovski, Steve

    2016-01-01

    We report the genome sequences of two double-stranded DNA siphoviruses, POR1 infective for Pseudomonas oryzihabitans and PAE1 infective for Pseudomonas aeruginosa The phage POR1 genome showed no nucleotide sequence homology to any other DNA phage sequence in the GenBank database, while phage PAE1 displayed synteny to P. aeruginosa phages M6, MP1412, and YuA. PMID:27313312

  16. An investigation of exploitation versus exploration in GBEA optimization of PORS 15 and 16 Problems

    SciTech Connect

    Koch, Kaelynn

    2012-01-01

    It was hypothesized that the variations in time to solution are driven by the competing mechanisms of exploration and exploitation.This thesis explores this hypothesis by examining two contrasting problems that embody the hypothesized tradeoff between exploration and exploitation. Plus one recall store (PORS) is an optimization problem based on the idea of a simple calculator with four buttons: plus, one, store, and recall. Integer addition and store are classified as operations, and one and memory recall are classified as terminals. The goal is to arrange a fixed number of keystrokes in a way that maximizes the numerical result. PORS 15 (15 keystrokes) represents the subset of difficult PORS problems and PORS 16 (16 keystrokes) represents the subset of PORS problems that are easiest to optimize. The goal of this work is to examine the tradeoff between exploitation and exploration in graph based evolutionary algorithm (GBEA) optimization. To do this, computational experiments are used to examine how solutions evolve in PORS 15 and 16 problems when solved using GBEAs. The experiment is comprised of three components; the graphs and the population, the evolutionary algorithm rule set, and the example problems. The complete, hypercube, and cycle graphs were used for this experiment. A fixed population size was used.

  17. Crystallographic analysis of Neisseria meningitidis PorB extracellular loops potentially implicated in TLR2 recognition.

    PubMed

    Kattner, Christof; Toussi, Deana N; Zaucha, Jan; Wetzler, Lee M; Rüppel, Nadine; Zachariae, Ulrich; Massari, Paola; Tanabe, Mikio

    2014-03-01

    Among all Neisseriae species, Neisseria meningitidis and Neisseria gonorrhoeae are the only human pathogens, causative agents of bacterial meningitis and gonorrhoea, respectively. PorB, a pan-Neisseriae trimeric porin that mediates diffusive transport of essential molecules across the bacterial outer membrane, is also known to activate host innate immunity via Toll-like receptor 2 (TLR2)-mediated signaling. The molecular mechanism of PorB binding to TLR2 is not known, but it has been hypothesized that electrostatic interactions contribute to ligand/receptor binding. Strain-specific sequence variability in the surface-exposed loops of PorB which are potentially implicated in TLR2 binding, may explain the difference in TLR2-mediated cell activation in vitro by PorB homologs from the commensal Neisseriae lactamica and the pathogen N. meningitidis. Here, we report a comparative structural analysis of PorB from N. meningitidis serogroup B strain 8765 (63% sequence homology with PorB from N. meningitidis serogroup W135) and a mutant in which amino acid substitutions in the extracellular loop 7 lead to significantly reduced TLR2-dependent activity in vitro. We observe that this mutation both alters the loop conformation and causes dramatic changes of electrostatic surface charge, both of which may affect TLR2 recognition and signaling. PMID:24361688

  18. Structural basis for solute transport, nucleotide regulation, and immunological recognition of Neisseria meningitidis PorB

    SciTech Connect

    Tanabe, Mikio; Nimigean, Crina M.; Iverson, T.M.

    2010-06-25

    PorB is the second most prevalent outer membrane protein in Neisseria meningitidis. PorB is required for neisserial pathogenesis and can elicit a Toll-like receptor mediated host immune response. Here, the x-ray crystal structure of PorB has been determined to 2.3 {angstrom} resolution. Structural analysis and cocrystallization studies identify three putative solute translocation pathways through the channel pore: One pathway transports anions nonselectively, one transports cations nonselectively, and one facilitates the specific uptake of sugars. During infection, PorB likely binds host mitochondrial ATP, and cocrystallization with the ATP analog AMP-PNP suggests that binding of nucleotides regulates these translocation pathways both by partial occlusion of the pore and by restricting the motion of a putative voltage gating loop. PorB is located on the surface of N. meningitidis and can be recognized by receptors of the host innate immune system. Features of PorB suggest that Toll-like receptor mediated recognition outer membrane proteins may be initiated with a nonspecific electrostatic attraction.

  19. Por Secretion System-Dependent Secretion and Glycosylation of Porphyromonas gingivalis Hemin-Binding Protein 35

    PubMed Central

    Shoji, Mikio; Sato, Keiko; Yukitake, Hideharu; Kondo, Yoshio; Narita, Yuka; Kadowaki, Tomoko; Naito, Mariko; Nakayama, Koji

    2011-01-01

    The anaerobic Gram-negative bacterium Porphyromonas gingivalis is a major pathogen in severe forms of periodontal disease and refractory periapical perodontitis. We have recently found that P. gingivalis has a novel secretion system named the Por secretion system (PorSS), which is responsible for secretion of major extracellular proteinases, Arg-gingipains (Rgps) and Lys-gingipain. These proteinases contain conserved C-terminal domains (CTDs) in their C-termini. Hemin-binding protein 35 (HBP35), which is one of the outer membrane proteins of P. gingivalis and contributes to its haem utilization, also contains a CTD, suggesting that HBP35 is translocated to the cell surface via the PorSS. In this study, immunoblot analysis of P. gingivalis mutants deficient in the PorSS or in the biosynthesis of anionic polysaccharide-lipopolysaccharide (A-LPS) revealed that HBP35 is translocated to the cell surface via the PorSS and is glycosylated with A-LPS. From deletion analysis with a GFP-CTD[HBP35] green fluorescent protein fusion, the C-terminal 22 amino acid residues of CTD[HBP35] were found to be required for cell surface translocation and glycosylation. The GFP-CTD fusion study also revealed that the CTDs of CPG70, peptidylarginine deiminase, P27 and RgpB play roles in PorSS-dependent translocation and glycosylation. However, CTD-region peptides were not found in samples of glycosylated HBP35 protein by peptide map fingerprinting analysis, and antibodies against CTD-regions peptides did not react with glycosylated HBP35 protein. These results suggest both that the CTD region functions as a recognition signal for the PorSS and that glycosylation of CTD proteins occurs after removal of the CTD region. Rabbits were used for making antisera against bacterial proteins in this study. PMID:21731719

  20. Molecular characterisation of Porcine rubulavirus (PorPV) isolates from different outbreaks in Mexico.

    PubMed

    Cuevas-Romero, S; Rivera-Benítez, J F; Blomström, A-L; Ramliden, M; Hernández-Baumgarten, E; Hernández-Jáuregui, P; Ramírez-Mendoza, H; Berg, M

    2016-02-01

    Since the report of the initial outbreak of Porcine rubulavirus (PorPV) infection in pigs, only one full-length genome from 1984 (PorPV-LPMV/1984) has been characterised. To investigate the overall genetic variation, full-length gene nucleotide sequences of current PorPV isolates were obtained from different clinical cases of infected swine. Genome organisation and sequence analysis of the encoded proteins (NP, P, F, M, HN and L) revealed high sequence conservation of the NP protein and the expression of the P and V proteins in all PorPV isolates. The V protein of one isolate displayed a mutation that has been implicated to antagonise the antiviral immune responses of the host. The M protein indicated a variation in a short region that could affect the electrostatic charge and the interaction with the membrane. One PorPV isolate recovered from the lungs showed a mutation at the cleavage site (HRKKR) of the F protein that could represent an important factor to determine the tissue tropism and pathogenicity of this virus. The HN protein showed high sequence identity through the years (up to 2013). Additionally, a number of sequence motifs of very high amino acid conservation among the PorPV isolates important for polymerase activity of the L protein have been identified. In summary, genetic comparisons and phylogenetic analyses indicated that three different genetic variants of PorPV are currently spreading within the swine population, and a new generation of circulating virus with different characteristics has begun to emerge.

  1. Oral administration of recombinant Neisseria meningitidis PorA genetically fused to H. pylori HpaA antigen increases antibody levels in mouse serum, suggesting that PorA behaves as a putative adjuvant

    PubMed Central

    Vasquez, Abel E; Manzo, Ricardo A; Soto, Daniel A; Barrientos, Magaly J; Maldonado, Aurora E; Mosqueira, Macarena; Avila, Anastasia; Touma, Jorge; Bruce, Elsa; Harris, Paul R; Venegas, Alejandro

    2015-01-01

    The Neisseria meningitidis outer membrane protein PorA from a Chilean strain was purified as a recombinant protein. PorA mixed with AbISCO induced bactericidal antibodies against N. meningitidis in mice. When PorA was fused to the Helicobacter pylori HpaA antigen gene, the specific response against H. pylori protein increased. Splenocytes from PorA-immunized mice were stimulated with PorA, and an increase in the secretion of IL-4 was observed compared with that of IFN-γ. Moreover, in an immunoglobulin sub-typing analysis, a substantially higher IgG1 level was found compared with IgG2a levels, suggesting a Th2-type immune response. This study revealed a peculiar behavior of the purified recombinant PorA protein per se in the absence of AbISCO as an adjuvant. Therefore, the resistance of PorA to proteolytic enzymes, such as those in the gastrointestinal tract, was analyzed, because this is an important feature for an oral protein adjuvant. Finally, we found that PorA fused to the H. pylori HpaA antigen, when expressed in Lactococcus lactis and administered orally, could enhance the antibody response against the HpaA antigen approximately 3 fold. These observations strongly suggest that PorA behaves as an effective oral adjuvant. PMID:25750999

  2. Informe a la Nación de mortalidad por cáncer sigue bajando

    Cancer.gov

    El Informe Anual a la Nación sobre el Estado del Cáncer, de 1975 a 2009, indica que los índices generales de mortalidad por cáncer siguen bajando en los Estados Unidos en hombres y mujeres, entre todos los grupos raciales y étnicos principales y para todo

  3. Structure and function of the PorB porin from disseminating Neisseria gonorrhoeae.

    PubMed

    Zeth, Kornelius; Kozjak-Pavlovic, Vera; Faulstich, Michaela; Fraunholz, Martin; Hurwitz, Robert; Kepp, Oliver; Rudel, Thomas

    2013-02-01

    The outer membrane of Gram-negative bacteria contains a large number of channel-forming proteins, porins, for the uptake of small nutrient molecules. Neisseria gonorrhoeae PorBIA (PorB of serotype A) are associated with disseminating diseases and mediate a rapid bacterial invasion into host cells in a phosphate-sensitive manner. To gain insights into this structure-function relationship we analysed PorBIA by X-ray crystallography in the presence of phosphate and ATP. The structure of PorBIA in the complex solved at a resolution of 3.3 Å (1 Å=0.1 nm) displays a surplus of positive charges inside the channel. ATP ligand-binding in the channel is co-ordinated by the positively charged residues of the channel interior. These residues ligate the aromatic, sugar and pyrophosphate moieties of the ligand. Two phosphate ions were observed in the structure, one of which clamped by two arginine residues (Arg92 and Arg124) localized at the extraplasmic channel exit. A short β-bulge in β2-strand together with the long L3 loop narrow the barrel diameter significantly and further support substrate specificity through hydrogen bond interactions. Interestingly the structure also comprised a small peptide as a remnant of a periplasmic protein which physically links porin molecules to the peptidoglycan network. To test the importance of Arg92 on bacterial invasion the residue was mutated. In vivo assays of bacteria carrying a R92S mutation confirmed the importance of this residue for host-cell invasion. Furthermore systematic sequence and structure comparisons of PorBIA from Neisseriaceae indicated Arg92 to be unique in disseminating N. gonorrhoeae thereby possibly distinguishing invasion-promoting porins from other neisserial porins.

  4. Detección y estudio mediante Fluorescencia Inducida por Láser de radicales libres formados por Disociación Multifotónica Infrarroja

    NASA Astrophysics Data System (ADS)

    Santos, M.; Díaz, L.; Torresano, J. A.; Rubio, L.; Samoudi, B.

    Una de las principales aplicaciones actuales de los procesos de disociación multifotónica inducidos por radiación láser infrarroja (DMI) es la producción de radiales libres, con el fin de estudiar sus propiedades cinéticas y espectroscópicas. La disociación de moléculas poliatómicas en el IR con láseres de CO2 tiene lugar desde la superficie de energía molecular mas baja y conduce generalmente a la formación de fragmentos en el estado electrónico fundamental, con diversos grados de excitación vibracional. En el Grupo de Procesos Multifotónicos del Instituto de Estructura de la Materia del C.S.I.C. hemos puesto a punto la técnica de Fluorescencia Inducida por Láser (LIF) para la detección y análisis en tiempo real de los fragmentos producidos en la DMI inducida mediante uno o dos campos láseres de diferentes longitudes de onda. Objetivos de nuestro trabajo han sido el estudio de los canales de disociación mayoritarios y de las especies transitoria producidas, así como de la distribución de energía interna con que éstas son generadas. En particular hemos detectado mediante LIF las especies: C2, CF, CH, SiH2, CF2, CH2, SiHCl, y CF3 a partir de la disociación de, entre otras, las siguientes moléculas: C2H3Br, C3F6, C4H8Si, C2H5ClSi y CH5ClSi. En este trabajo presentamos algunos de los resultados obtenidos mediante el estudio por LIF de estos radicales: estudio temporal de la señal LIF obtenida con determinación de tiempos de vida, espectros de excitación y fluorescencia, temperaturas vibracionales de formación, variación de la intensidad LIF con el tiempo de retraso entre los láseres de disociación y prueba, etc.

  5. ATP for the portable 500 CFM exhauster POR-005 skid C

    SciTech Connect

    Keller, C.M.

    1997-06-27

    This Acceptance Test Plan is for a 500 CFM Portable Exhauster POR-005 to be used for saltwell pumping. The Portable Exhauster System will be utilized to eliminate potential flammable gases that may exist within the dome space of the tank. This Acceptance Plan will test and verify that the exhauster meets the specified design criteria, safety requirements, operations requirements, and will provide a record of the functional test results.

  6. ATP for the portable 500 CFM exhauster POR-006 skid D

    SciTech Connect

    Keller, C.M.

    1997-07-29

    This Acceptance Test Plan is for a 500 CFM Portable Exhauster POR-006 to be used for saltwell pumping. The Portable Exhauster System will be utilized to eliminate potential flammable gases that may exist within the dome space of the tank. This Acceptance Plan will test and verify that the exhauster meets the specified design criteria, safety requirements, operations requirements, and will provide a record of the functional test results.

  7. ATP for the portable 500 CFM exhauster POR-004 skid B

    SciTech Connect

    Keller, C.M.

    1997-05-06

    This Acceptance Test Plan is for a 500 CFM Portable Exhauster POR-004 to be used for saltwell pumping. The Portable Exhauster System will be utilized to eliminate potential flammable gases that may exist within the dome space of the tank. This Acceptance Plan will test and verify that the exhauster meets the specified design criteria, safety requirements, operations requirements, and will provide a record of the functional test results.

  8. Development of a method for simultaneous analysis of PCDDs, PCDFs, PCBs, PBDEs, PCNs and PAHs in Antarctic air.

    PubMed

    Piazza, R; Gambaro, A; Argiriadis, E; Vecchiato, M; Zambon, S; Cescon, P; Barbante, C

    2013-01-01

    The development of a unique analytical method for the determination of five classes of persistent organic pollutants (POPs) in atmospheric gas and the particle phase through gas chromatography coupled to high-resolution mass spectrometry is presented. Every step of the pre-analytical and analytical optimization process is described. Great effort was put into simplifying the traditional techniques, with reference to EPA and literature methods. Automated instruments were used for sample extraction and cleanup in order to enhance repeatability and reduce contamination risks. Unlike most common approaches, no separation of the analytes was performed before the GC analysis in order to avoid sample fractionation and to save time and materials. This allowed low instrumental and method detection limits (pg to sub-pg) to be achieved. Accuracy and precision were tested by fortifying the matrix and analysing standard reference materials (NIST SRM 1649b Urban Dust and 2585 Organic Contaminants in House Dust). The method was applied to five samples from Terra Nova Bay, Antarctica. Concentrations of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) are presented. Lighter compounds dominate the distribution and are mainly present in the gaseous phase. The observed pattern may be attributable to long-range transport. Results are in general agreement with literature data, where available.

  9. Relative potency based on hepatic enzyme induction predicts immunosuppressive effects of a mixture of PCDDS/PCDFS and PCBS

    SciTech Connect

    Smialowicz, R.J.; DeVito, M.J. Williams, W.C.; Birnbaum, L.S.

    2008-03-15

    The toxic equivalency factor (TEF) approach was employed to compare immunotoxic potency of mixtures containing polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), using the antibody response to sheep erythrocytes (SRBC). Mixture-1 (MIX-1) contained TCDD, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-pentachlorodibenzofuran (1-PeCDF), 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF), and 1,2,3,4,6,7,8,9-octachlorodibenzofuran (OCDF). Mixture-2 (MIX-2) contained MIX-1 and the following PCBs, 3,3',4,4'-tetrachlorobiphenyl (IUPAC No. 77), 3,3',4,4',5-pentachlorobiphenyl (126), 3,3',4,4',5,5N-hexachlorobiphenyl (169), 2,3,3',4,4'-pentachlorobiphenyl (105), 2,3',4,4',5-pentachlorobiphenyl (118), and 2,3,3',4,4',5-hexachlorobiphenyl (156). The mixture compositions were based on relative chemical concentrations in food and human tissues. TCDD equivalents (TEQ) of the mixture were estimated using relative potency factors from hepatic enzyme induction in mice [DeVito, M.J., Diliberto, J.J., Ross, D.G., Menache, M.G., Birnbaum, L.S., 1997. Dose-response relationships for polyhalogenated dioxins and dibenzofurans following subchronic treatment in mice. I .CYP1A1 and CYP1A2 enzyme activity in liver, lung and skin. Toxicol. Appl. Pharmacol. 130, 197-208; DeVito, M.J., Menache, G., Diliberto, J.J., Ross, D.G., Birnbaum L.S., 2000. Dose-response relationships for induction of CYP1A1 and CYP1A2 enzyme activity in liver, lung, and skin in female mice following subchronic exposure to polychlorinated biphenyls. Toxicol. Appl. Pharmacol. 167, 157-172] Female mice received 0, 1.5, 15, 150 or 450 ng TCDD/kg/day or approximately 0, 1.5, 15, 150 or 450 ng TEQ/kg/day of MIX-1 or MIX-2 by gavage 5 days per week for 13 weeks. Mice were immunized 3 days after the last exposure and 4 days later, body, spleen, thymus, and liver weights were measured, and antibody response to SRBCs was observed. Exposure to TCDD, MIX-1, and MIX-2 suppressed the antibody response in a dose-dependent manner. Two-way ANOVA indicated no differences in the response between TCDD and the mixtures for body weight, spleen/body weight and decreased antibody responses. The results support the use of the TEF methodology and suggest that immune suppression by dioxin-like chemicals may be of concern at or near background human exposures.

  10. Levels of PCDDs, PCDFs and dioxin-like PCBs in raw cow's milk collected in France in 2006.

    PubMed

    Durand, Benoit; Dufour, Barbara; Fraisse, Daniel; Defour, Stéphanie; Duhem, Koenraad; Le-Barillec, Karine

    2008-01-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) as well as polychlorinated biphenyls (PCBs) are widespread environmental contaminants. A French national survey was carried out in April 2006 to assess the concentrations of PCDD/Fs and dioxin-like PCBs (DL-PCBs) in raw cow's milk. A random sampling scheme stratified by region was applied to collect 239 raw milk samples from 93 plants belonging to 17 dairy companies. Compared to a previous survey led in 1998 analyzing half-skimmed drinking milk in France, the PCDD/Fs level was cut by half, with an average concentration of 0.33 pg toxic equivalent (TEQ)/g fat in 2006. The mean DL-PCBs concentration was 0.57 pg TEQ/g fat and subsequently the sum of PCDD/Fs and DL-PCBs was 0.90 pg/g fat, values below the thresholds defined by the European Union regulations. PMID:17707881

  11. Expression, purification and preliminary X-ray analysis of the Neisseria meningitidis outer membrane protein PorB

    SciTech Connect

    Tanabe, Mikio; Iverson, Tina M.

    2010-01-28

    The Neisseria meningitidis outer membrane protein PorB was expressed in Escherichia coli and purified from inclusion bodies by denaturation in urea followed by refolding in buffered LDAO on a size-exclusion column. PorB has been crystallized in three different crystal forms: C222, R32 and P6{sub 3}. The C222 crystal form may contain either one or two PorB monomers in the asymmetric unit, while both the R32 and P6{sub 3} crystal forms contained one PorB monomer in the asymmetric unit. Of the three, the P6{sub 3} crystal form had the best diffraction quality, yielding data extending to 2.3 {angstrom} resolution.

  12. Effect of SPM-based cleaning POR on EUV mask performance

    NASA Astrophysics Data System (ADS)

    Choi, Jaehyuck; Lee, Han-shin; Yoon, Jinsang; Shimomura, Takeya; Friz, Alex; Montgomery, Cecilia; Ma, Andy; Goodwin, Frank; Kang, Daehyuk; Chung, Paul; Shin, Inkyun; Cho, H.

    2011-11-01

    EUV masks include many different layers of various materials rarely used in optical masks, and each layer of material has a particular role in enhancing the performance of EUV lithography. Therefore, it is crucial to understand how the mask quality and patterning performance can change during mask fabrication, EUV exposure, maintenance cleaning, shipping, or storage. The fact that a pellicle is not used to protect the mask surface in EUV lithography suggests that EUV masks may have to undergo more cleaning cycles during their lifetime. More frequent cleaning, combined with the adoption of new materials for EUV masks, necessitates that mask manufacturers closely examine the performance change of EUV masks during cleaning process. We have investigated EUV mask quality and patterning performance during 30 cycles of Samsung's EUV mask SPM-based cleaning and 20 cycles of SEMATECH ADT exposure. We have observed that the quality and patterning performance of EUV masks does not significantly change during these processes except mask pattern CD change. To resolve this issue, we have developed an acid-free cleaning POR and substantially improved EUV mask film loss compared to the SPM-based cleaning POR.

  13. Diagnóstico diferencial en la encefalitis por anticuerpos contra el receptor NMDA

    PubMed Central

    González-Valcárcel, J.; Rosenfeld, M.R.; Dalmau, J.

    2011-01-01

    Resumen Introducción La encefalitis por anticuerpos contra el receptor de NMDA (NMDAR) suele desarrollarse como un síndrome característico de evolución multifásica y diagnóstico diferencial amplio. Pacientes Presentamos a 2 pacientes diagnosticadas de encefalitis por anticuerpos NMDAR con un cuadro clínico típico, pero que inicialmente señaló otras etiologías. Discusión La afectación frecuente de pacientes jóvenes con manifestaciones psiquiátricas prominentes indica frecuentemente otras consideraciones diagnósticas; las más frecuentes son las encefalitis virales, los procesos psiquiátricos y el síndrome neuroléptico maligno. Varios síndromes previamente definidos de manera parcial o descriptiva en adultos y pacientes pediátricos probablemente eran casos de encefalitis anti-NMDAR. Conclusiones La encefalitis anti-NMDAR debe considerarse en pacientes jóvenes con manifestaciones psiquiátricas subagudas, movimientos anormales y alteraciones autonómicas. La caracterización clínica e inmunológica de esta enfermedad ha llevado a la identificación de nuevos anticuerpos que afectan a procesos de memoria, aprendizaje, conducta y psicosis. PMID:20964986

  14. Substrate-specific modulation of CYP3A4 activity by genetic variants of cytochrome P450 oxidoreductase (POR)

    PubMed Central

    Agrawal, Vishal; Choi, Ji Ha; Giacomini, Kathleen M.; Miller, Walter L.

    2010-01-01

    Objectives CYP3A4 receives electrons from P450 oxidoreductase (POR) to metabolize about 50% of clinically used drugs. There is substantial inter-individual variation in CYP3A4 catalytic activity that is not explained by CYP3A4 genetic variants. CYP3A4 is flexible and distensible, permitting it to accommodate substrates varying in shape and size. To elucidate mechanisms of variability in CYP3A4 catalysis, we examined the effects of genetic variants of POR, and explored the possibility that substrate-induced conformational changes in CYP3A4 differentially affect the ability of POR variants to support catalysis. Methods We expressed human CYP3A4 and four POR variants (Q153R, A287P, R457H, A503V) in bacteria, reconstituted them in vitro and measured the Michaelis constant and maximum velocity with testosterone, midazolam, quinidine and erythromycin as substrates. Results POR A287P and R457H had low activity with all substrates; Q153R had 76–94% of wild type (WT) activity with midazolam and erythromycin, but 129–150% activity with testosterone and quinidine. The A503V polymorphism reduced CYP3A4 activity to 61–77% of wild type with testosterone and midazolam, but had nearly wild type activity with quinidine and erythromycin. Conclusion POR variants affect CYP3A4 activities. The impact of a POR variant on catalysis by CYP3A4 is substrate-specific, probably due to substrate-induced conformational changes in CYP3A4. PMID:20697309

  15. Reconstrução tridimensional de arcos magnéticos por tomografia

    NASA Astrophysics Data System (ADS)

    Simões, P. J. A.; Costa, J. E. R.

    2003-08-01

    Uma explosão solar é uma variação súbita do brilho que ocorre nas regiões ativas da atmosfera solar. Estas regiões são constituídas por um plasma magnetizado com intensa indução magnética e em cenários bem complexos como visto recentemente através de experimentos embarcados em satélites operando instrumentos em raios X moles e ultra-violeta distante. A energia magnética, que pode ser armazenada por um período de horas até dias em configurações magnéticas estressadas, é subitamente lançada na atmosfera solar e transferida para partículas como elétrons, prótons e núcleos pesados, que são acelerados e/ou aquecidos, produzindo radiação eletromagnética. A proposta final deste projeto é determinar as características espaciais de alta resolução da emissão e polarização girossincrotrônica de explosões solares em ambientes complexos de campos magnéticos. Os recentes resultados da emissão difusa em EUV apresentado pelos satélites TRACE e SOHO dos arcos magnéticos conectando as diferentes polaridades magnéticas sobre as regiões ativas possibilitam novas abordagens sobre o papel do campo magnético na emissão em rádio. Nesta etapa apresentamos os resultados da reconstrução da geometria tridimensional das linhas de força destes arcos utilizando técnicas tomográficas, a partir de imagens de alta resolução espacial obtidas pelo instrumento EIT (Extreme ultraviolet Imaging Telescope), além da modelagem das induções magnéticas por um campo dipolar e as densidades de partículas aceleradas. Utilizamos para a reconstrução geométrica, imagens tomadas em vários ângulos dos arcos devido à rotacão solar. Com estes resultados, daremos continuidade ao projeto, com os cálculos da transferência radiativa nos modos ordinário e extraordinário de propagação da radiação girossincrotrônica de explosões solares.

  16. Using the PORS Problems to Examine Evolutionary Optimization of Multiscale Systems

    SciTech Connect

    Reinhart, Zachary; Molian, Vaelan; Bryden, Kenneth

    2013-01-01

    Nearly all systems of practical interest are composed of parts assembled across multiple scales. For example, an agrodynamic system is composed of flora and fauna on one scale; soil types, slope, and water runoff on another scale; and management practice and yield on another scale. Or consider an advanced coal-fired power plant: combustion and pollutant formation occurs on one scale, the plant components on another scale, and the overall performance of the power system is measured on another. In spite of this, there are few practical tools for the optimization of multiscale systems. This paper examines multiscale optimization of systems composed of discrete elements using the plus-one-recall-store (PORS) problem as a test case or study problem for multiscale systems. From this study, it is found that by recognizing the constraints and patterns present in discrete multiscale systems, the solution time can be significantly reduced and much more complex problems can be optimized.

  17. Rescue of cytochrome P450 oxidoreductase (Por) mouse mutants reveals functions in vasculogenesis, brain and limb patterning linked to retinoic acid homeostasis.

    PubMed

    Ribes, Vanessa; Otto, Diana M E; Dickmann, Leslie; Schmidt, Katy; Schuhbaur, Brigitte; Henderson, Colin; Blomhoff, Rune; Wolf, C Roland; Tickle, Cheryll; Dollé, Pascal

    2007-03-01

    Cytochrome P450 oxidoreductase (POR) acts as an electron donor for all cytochrome P450 enzymes. Knockout mouse Por(-/-) mutants, which are early embryonic (E9.5) lethal, have been found to have overall elevated retinoic acid (RA) levels, leading to the idea that POR early developmental function is mainly linked to the activity of the CYP26 RA-metabolizing enzymes (Otto et al., Mol. Cell. Biol. 23, 6103-6116). By crossing Por mutants with a RA-reporter lacZ transgene, we show that Por(-/-) embryos exhibit both elevated and ectopic RA signaling activity e.g. in cephalic and caudal tissues. Two strategies were used to functionally demonstrate that decreasing retinoid levels can reverse Por(-/-) phenotypic defects, (i) by culturing Por(-/-) embryos in defined serum-free medium, and (ii) by generating compound mutants defective in RA synthesis due to haploinsufficiency of the retinaldehyde dehydrogenase 2 (Raldh2) gene. Both approaches clearly improved the Por(-/-) early phenotype, the latter allowing mutants to be recovered up until E13.5. Abnormal brain patterning, with posteriorization of hindbrain cell fates and defective mid- and forebrain development and vascular defects were rescued in E9.5 Por(-/-) embryos. E13.5 Por(-/-); Raldh2(+/-) embryos exhibited abdominal/caudal and limb defects that strikingly phenocopy those of Cyp26a1(-/-) and Cyp26b1(-/-) mutants, respectively. Por(-/-); Raldh2(+/-) limb buds were truncated and proximalized and the anterior-posterior patterning system was not established. Thus, POR function is indispensable for the proper regulation of RA levels and tissue distribution not only during early embryonic development but also in later morphogenesis and molecular patterning of the brain, abdominal/caudal region and limbs. PMID:17126317

  18. Global Microlending in Education Reform: Enseñá Por Argentina and the Neoliberalization of the Grassroots

    ERIC Educational Resources Information Center

    Friedrich, Daniel S.

    2010-01-01

    This article examines the workings and underlying assumptions behind Enseñá por Argentina (Teach for Argentina), one specific program that takes part in the larger and expanding network of Teach for All, by thinking about the ways in which a global push for redefining teaching and teacher education encounters local characteristics and histories,…

  19. [Professor Frantisek Por MD and Professor Robert Klopstock MD, students at Budapest and Prague Faculties of Medicine].

    PubMed

    Mydlík, M; Derzsiová, K

    2010-11-01

    Professor Frantisek Por MD and Professor Robert Klopstock MD were contemporaries, both born in 1899, one in Zvolen, the other in Dombovar, at the time of Austro-Hungarian Monarchy. Prof. Por attended the Faculty of Medicine in Budapest from 1918 to 1920, and Prof. Klopstock studied at the same place between 1917 and 1919. From 1920 until graduation on 6th February 1926, Prof. Por continued his studies at the German Faculty of Medicine, Charles University in Prague. Prof. Klopstock had to interrupt his studies in Budapest due to pulmonary tuberculosis; he received treatment at Tatranske Matliare where he befriended Franz Kafka. Later, upon Kafka's encouragement, he changed institutions and continued his studies at the German Faculty of Medicine, Charles University in Prague, where he graduated the first great go. It is very likely that, during their studies in Budapest and Prague, both professors met repeatedly, even though their life paths later separated. Following his graduation, Prof. Por practiced as an internist in Prague, later in Slovakia, and from 1945 in Kosice. In 1961, he was awarded the title of university professor of internal medicine at the Faculty of Medicine, Pavol Jozef Safarik University in Kosice, where he practiced until his death in 1980. Prof. Klopstock continued his studies in Kiel and Berlin. After his graduation in 1933, he practiced in Berlin as a surgeon and in 1938 left for USA. In 1962, he was awarded the title of university professor of pulmonary surgery in NewYork, where he died in 1972.

  20. Sequence evolution of the porB gene of Neisseria gonorrhoeae and Neisseria meningitidis: evidence of positive Darwinian selection.

    PubMed

    Smith, N H; Maynard Smith, J; Spratt, B G

    1995-05-01

    Protein 1 (PI) is a major porin of Neisseria gonorrhoeae and Neisseria meningitidis and is encoded by a single locus, porB. Alleles of the porB locus of N. gonorrhoeae are assigned to two homology groups, PI(A) and PI(B), on the basis of immunological and structural similarity. In a like manner, alleles of the porB locus of the closely related bacterium, N. meningitidis, are allocated into class 2 and class 3 homology groups. An individual strain of N. gonorrhoeae or N. meningitidis expresses either one or other of these porin homology groups but never both, and the antigenic reactions of these highly diverse outer membrane proteins form part of the N. gonorrhoeae and N. meningitidis serotyping schemes. A comparison of the number of synonymous and nonsynonymous substitutions per site between the two most divergent alleles of each of these four groups of porB alleles shows that PI(A) alleles have accumulated significantly more nonsynonymous substitutions per site than synonymous substitutions. In contrast the distribution of synonymous and nonsynonymous substitutions between alleles of class 2 and class 3 porins are not significantly different from random. We localize the regions of the PI(A) alleles with an excess of amino acid changes to the surface-exposed loops of these outer membrane proteins and suggest that positive Darwinian selection for diversity, driven by the human immune system, can most easily explain the allelic polymorphism and the pattern of synonymous and nonsynonymous substitutions.

  1. Functional Expression of the PorAH Channel from Corynebacterium glutamicum in Cell-free Expression Systems

    PubMed Central

    Rath, Parthasarathi; Demange, Pascal; Saurel, Olivier; Tropis, Marielle; Daffé, Mamadou; Dötsch, Volker; Ghazi, Alexandre; Bernhard, Frank; Milon, Alain

    2011-01-01

    PorA and PorH are two small membrane proteins from the outer membrane of Corynebacterium glutamicum, which have been shown to form heteromeric ion channels and to be post-translationally modified by mycolic acids. Any structural details of the channel could not be analyzed so far due to tremendous difficulties in the production of sufficient amounts of protein samples. Cell-free (CF) expression is a new and remarkably successful strategy for the production of membrane proteins for which toxicity, membrane targeting, and degradation are key issues. In addition, reaction conditions can easily be modified to modulate the quality of synthesized protein samples. We developed an efficient CF expression strategy to produce the channel subunits devoid of post-translational modifications. 15N-labeled PorA and PorH samples were furthermore characterized by NMR and gave well resolved spectra, opening the way for structural studies. The comparison of ion channel activities of CF-expressed proteins with channels isolated from C. glutamicum gave clear insights on the influence of the mycolic acid modification of the two subunits on their functional properties. PMID:21799011

  2. jPOR: An ImageJ macro to quantify total optical porosity from blue-stained thin sections

    NASA Astrophysics Data System (ADS)

    Grove, Clayton; Jerram, Dougal A.

    2011-11-01

    A fast and effective method has been developed to measure total optical porosity (TOP) of blue resin-impregnated thin sections. This utilises a macro file (jPOR.txt) for ImageJ, which can be used on digital photomicrographs of thin sections. The method requires no specialised scientific equipment and can be run entirely using free to download software. Digital images are acquired from blue resin-impregnated thin sections using a conventional film scanner in the present study, though the technique can be applied to any high resolution colour digital acquired by different means (e.g., flat bed scanning, digital capture). Images are preprocessed using a newly developed custom 8-bit palette and analysed for porosity in ImageJ using the simple to use jPOR macro. Our method rapidly calculates TOP for batches of images with or without the option of user adjustment. Results are compared with conventional methods (e.g., to point counting), and tested with several users to estimate any user variability. jPOR provided comparable results to more time-consuming point counting, but with significantly less "counting error" and less interoperator variability than published point counting studies. The jPOR macro has been integrated into a macro tool set that can be configured to be run on ImageJ start up.

  3. Functional POR A503V is associated with the risk of bladder cancer in a Chinese population

    PubMed Central

    Xiao, Xue; Ma, Gaoxiang; Li, Shushu; Wang, Meilin; Liu, Nian; Ma, Lan; Zhang, Zhan; Chu, Haiyan; Zhang, Zhengdong; Wang, Shou-Lin

    2015-01-01

    Human cytochrome P450 oxidoreductase (POR) plays important roles in the metabolism of exogenous carcinogens and endogenous sterol hormones. However, few studies have explored the association between POR variants and the risk of bladder cancer. In this study, we first sequenced all 16 POR exons among 50 randomly selected controls, and found three variants, rs1135612, rs1057868 (A503V) and rs2228104, which were then assessed the relation to risk of bladder cancer in a case-control study of 1,050 bladder cancer cases and 1,404 cancer-free controls in a Chinese population. People with A503V TT genotype have a decreased risk of bladder cancer in a recessive model (TT vs. CC/CT, OR = 0.73, 95% CI = 0.57–0.93), which was more pronounced among elderly male, non-smoking, subjects. Especially, A503V TT genotype showed a protective effect in the invasive tumor stage. Functional analysis revealed that A503V activity decreased in cytochrome c reduction (50.5 units/mg vs. 135.4 units/mg), mitomycin C clearance (38.3% vs. 96.8%), and mitomycin C-induced colony formation (78.0 vs 34.3 colonies per dish). The results suggested that POR A503V might decrease the risk of bladder cancer by reducing its metabolic activity, and should be a potential biomarker for predicting the susceptibility to human bladder cancer. PMID:26123203

  4. Inversor Resonante de Tres Elementos L-LC con Caracteristica Cortocircuitable para Aplicaciones de Calentamiento por Induccion

    NASA Astrophysics Data System (ADS)

    Espi Huerta, Jose Miguel

    Los generadores de calentamiento por induccion son puentes inversores con carga resonante, cuya mision es basicamente crear una corriente sinusoidal de gran amplitud sobre la "bobina de caldeo", que forma parte del tanque resonante. En el interior de esta bobina se introduce la pieza que se desea calentar. EI campo magnetico creado induce corrientes superficiales (corrientes de Foucault) sobre la pieza, que producen su calentamiento. Los tanques resonantes (tambien llamados osciladores) utilizados en la actualidad son el resonante serie y el resonante paralelo. Aunque ya desde hace algun tiempo se vienen construyendo generadores de alta potencia basados en estos dos osciladores, el exito nunca ha. sido completo en ninguno de los dos casos. Tal y como se explica en la introduccion de esta memoria, los puentes inversores utilizados deben operar sobre una carga inductiva (corriente retrasada) para evitar el fenomeno de la recuperacion inversa de sus diodos y la consiguiente ruptura de los transistores. De la restriccion topologica anterior se deduce que el generador paralelo debe conmutar a frecuencias inferiores a la resonancia, y el serie a frecuencias superiores. A esta restriccion topologica hay que unir otra que es exclusiva del calentamiento por induccion: La corriente por la bobina de caldeo debe ser sinusoidal. De no ser asi, resultaria imposible disponer toda la potencia de calentamiento sobre la pieza en el espesor requerido por la aplicacion. Como consecuencia, los inversores no pueden operar por debajo de la frecuencia de resonancia del oscilador, pues en ese caso se amplifican los armonicos de orden superior de la tension/corriente de entrada situados sobre la resonancia, con la consiguiente distorsion de la corriente de salida. La conjuncion de las dos restricciones anteriores obligan al inversor paralelo a funcionar a la frecuencia de resonancia del oscilador. Esto imposibilita un control por variacion de frecuencia, regulandose la potencia desde la

  5. Encefalitis por anticuerpos contra el receptor de NMDA: experiencia con seis pacientes pediátricos. Potencial eficacia del metotrexato

    PubMed Central

    Bravo-Oro, Antonio; Abud-Mendoza, Carlos; Quezada-Corona, Arturo; Dalmau, Josep; Campos-Guevara, Verónica

    2016-01-01

    Introducción La encefalitis por anticuerpos contra el receptor de N-metil-D-aspartato (NMDA) es una entidad cada vez más diagnosticada en edad pediátrica. A diferencia de los adultos, en muchos casos no se asocia a tumores y las manifestaciones iniciales en niños más frecuentes son crisis convulsivas y trastornos del movimiento, mientras que en los adultos predominan las alteraciones psiquiátricas. Casos clínicos Presentamos seis casos pediátricos confirmados con anticuerpos contra la subunidad NR1 del receptor de NMDA en suero y líquido cefalorraquídeo. Cinco de los casos comenzaron con crisis convulsivas como manifestación clínica inicial antes de desarrollar el cuadro clásico de esta entidad. En todos los casos se utilizaron esteroides como primera línea de tratamiento, con los que sólo se observó control de las manifestaciones en uno, por lo que el resto de los pacientes requirió inmunomoduladores de segunda línea. Todos los pacientes recibieron metotrexato como tratamiento inmunomodulador para evitar recaídas y la evolución fue a la mejoría en todos ellos. Conclusiones En nuestra serie de pacientes con encefalitis por anticuerpos contra el receptor de NMDA, ninguno se asoció a tumores. Todos los casos recibieron metotrexato por lo menos durante un año, no observamos eventos adversos clínicos ni por laboratorio, ni hubo secuelas neurológicas ni recaídas durante el tratamiento. Aunque es una serie pequeña y es deseable incrementar el número y tiempo de evolución, consideramos el metotrexato una excelente alternativa como tratamiento inmunomodulador para esta patología. PMID:24150952

  6. Prevalencia y tamizaje del Trastorno por Déficit de Atención con Hiperactividad en Costa Rica

    PubMed Central

    Weiss, Nicholas T.; Schuler, Jovita; Monge, Silvia; McGough, James J.; Chavira, Denise; Bagnarello, Monica; Herrera, Luis Diego; Mathews, Carol A.

    2015-01-01

    Resumen La investigación tuvo como propósito estimar la prevalencia del Trastorno por Déficit de Atención con Hiperactividad (TDAH) en Costa Rica y determinar si la versión en español del cuestionario Swanson Nolan and Pelham Scale IV (SNAP-IV) es un instrumento de tamizaje útil en una población de niños y niñas escolares costarricenses. El instrumento fue entregado a padres y maestros de 425 niños entre 5 y 13 años de edad (promedio = 8.8). Todos fueron evaluados con el instrumento Swanson, Kotkin, Agler, M-Flynn and Pelham Scale (SKAMP). Su diagnóstico fue confirmado con una entrevista clínica. La sensibilidad y la especificidad del SNAP-IV fueron evaluadas como predictores de criterios de diagnóstico según el DSM-IV. La prevalencia puntual en la muestra del TDAH fue del 5%. El tamizaje más preciso lo hizo el SNAP-IV completado por el maestro en un corte de 20%, con una sensibilidad de 96% y una especificidad de un 82%. La sensibilidad de los instrumentos completados por los padres fue más baja que aquella de los maestros. El SNAP-IV completado por las maestras con un corte aislando el 20% de los mayores puntajes categorizó correctamente a un 87% de los sujetos. PMID:22432094

  7. The POR rs1057868–rs2868177 GC-GT diplotype is associated with high tacrolimus concentrations in early post-renal transplant recipients

    PubMed Central

    Liu, Shu; Chen, Rong-xin; Li, Jun; Zhang, Yu; Wang, Xue-ding; Fu, Qian; Chen, Ling-yan; Liu, Xiao-man; Huang, Hong-bing; Huang, Min; Wang, Chang-xi; Li, Jia-li

    2016-01-01

    Aim: Cytochrome P450 oxidoreductase (POR) is the only flavoprotein that donates electrons to all microsomal P450 enzymes (CYP), and several POR SNPs have been shown to be important contributors to altered CYP activity or CYP-mediated drug metabolism. In this study we examined the association between 6 POR SNPs and tacrolimus concentrations in Chinese renal transplant recipients. Methods: A total of 154 renal transplant recipients were enrolled. Genotyping of CYP3A5*3 and 6 POR SNPs was performed. All patients received a triple immunosuppressive regimen comprising tacrolimus, mycophenolate mofetil and prednisone. Dose-adjusted tacrolimus trough concentrations were obtained on d 7 (C0D7/D) after transplantation when steady-state concentration of tacrolimus was achieved (dosage had been unchanged for more than 3 d). Results: Tacrolimus C0D7/D in CYP3A5*3/*3/ POR rs1057868–rs2868177 GC-GT diplotype carriers was 1.62- and 2.72-fold higher than those in CYP3A5*3/*3/ POR rs1057868–rs2868177 GC-GT diplotype non-carriers and CYP3A5*1 carriers (220.17±48.09 vs 135.69±6.86 and 80.84±5.27 ng/mL/mg/kg, respectively, P<0.0001). Of CYP3A5*3/*3/ POR rs1057868-rs2868177GC-GT diplotype carriers, 85.71% exceeded the upper limit of the target range (8 ng/mL), which was also significantly higher compared with the latter two groups (14.29% and 0.00%, respectively, P<0.0001). The CYP3A5*3 and POR rs1057868–rs2868177 GC-GT diplotype explained 31.7% and 5.7%, respectively, of the inter-individual variability of tacrolimus C0D7/D, whereas the POR rs1057868–rs2868177 GC-GT diplotype could explain 10.9% of the inter-individual variability of tacrolimus C0D7/D in CYP3A5 non-expressers. Conclusion: The CYP3A5*3 and POR rs1057868–rs2868177 GC-GT diplotype accounted for the inter-individual variation of tacrolimus C0D7/D. Genotyping of POR rs1057868–rs2868177 diplotypes would help to differentiate initial tacrolimus dose requirements and to achieve early target C0 ranges in Chinese

  8. Targeting of Neisserial PorB to the mitochondrial outer membrane: an insight on the evolution of β-barrel protein assembly machines.

    PubMed

    Jiang, Jhih-Hang; Davies, John K; Lithgow, Trevor; Strugnell, Richard A; Gabriel, Kipros

    2011-11-01

    Mitochondria originated from Gram-negative bacteria through endosymbiosis. In modern day mitochondria, the Sorting and Assembly Machinery (SAM) is responsible for eukaryotic β-barrel protein assembly in the mitochondrial outer membrane. The SAM is the functional equivalent of the β-barrel assembly machinery found in the outer membrane of Gram-negative bacteria. In this study we examined the import pathway of a pathogenic bacterial protein, PorB, which is targeted from pathogenic Neisseria to the host mitochondria. We have developed a new method for measurement of PorB assembly into mitochondria that relies on the mobility shift exhibited by bacterial β-barrel proteins once folded and separated under semi-native electrophoretic conditions. We show that PorB is targeted to the outer mitochondrial membrane with a dependence on the intermembrane space shuttling chaperones and the core component of the SAM, Sam50, which is a functional homologue of BamA that is required for PorB assembly in bacteria. The peripheral subunits of the SAM, Sam35 and Sam37, which are essential for eukaryotic β-barrel protein assembly but do not have distinguishable functional homologues in bacteria, are not required for PorB assembly in eukaryotes. This shows that PorB uses an evolutionary conserved 'bacterial like' mechanism to infiltrate the host mitochondrial outer membrane. PMID:22032638

  9. Influence of Various Polymorphic Variants of Cytochrome P450 Oxidoreductase (POR) on Drug Metabolic Activity of CYP3A4 and CYP2B6

    PubMed Central

    Naranmandura, Hua; Zeng, Su; Chen, Shu Qing

    2012-01-01

    Cytochrome P450 oxidoreductase (POR) is known as the sole electron donor in the metabolism of drugs by cytochrome P450 (CYP) enzymes in human. However, little is known about the effect of polymorphic variants of POR on drug metabolic activities of CYP3A4 and CYP2B6. In order to better understand the mechanism of the activity of CYPs affected by polymorphic variants of POR, six full-length mutants of POR (e.g., Y181D, A287P, K49N, A115V, S244C and G413S) were designed and then co-expressed with CYP3A4 and CYP2B6 in the baculovirus-Sf9 insect cells to determine their kinetic parameters. Surprisingly, both mutants, Y181D and A287P in POR completely inhibited the CYP3A4 activity with testosterone, while the catalytic activity of CYP2B6 with bupropion was reduced to approximately ∼70% of wild-type activity by Y181D and A287P mutations. In addition, the mutant K49N of POR increased the CLint (Vmax/Km) of CYP3A4 up to more than 31% of wild-type, while it reduced the catalytic efficiency of CYP2B6 to 74% of wild-type. Moreover, CLint values of CYP3A4-POR (A115V, G413S) were increased up to 36% and 65% of wild-type respectively. However, there were no appreciable effects observed by the remaining two mutants of POR (i.e., A115V and G413S) on activities of CYP2B6. In conclusion, the extent to which the catalytic activities of CYP were altered did not only depend on the specific POR mutations but also on the isoforms of different CYP redox partners. Thereby, we proposed that the POR-mutant patients should be carefully monitored for the activity of CYP3A4 and CYP2B6 on the prescribed medication. PMID:22719896

  10. Análise dos Conceitos Astronômicos Apresentados por Professores de Algumas Escolas Estaduais Brasileiras

    NASA Astrophysics Data System (ADS)

    Voelzke, Marcos Rincon; Gonzaga, Edson Pereira

    2011-12-01

    A razão para o desenvolvimento deste trabalho baseia-se no fato de que muitos professores da Educação Básica (EB) não lidam com conceitos relacionados à astronomia, e quando o fazem eles simplesmente seguem livros didáticos que podem conter erros conceituais. Como é de conhecimento geral a astronomia é um dos conteúdos a serem ensinados na EB fazendo parte dos Parâmetros Curriculares Nacionais e das Propostas Curriculares do Estado de São Paulo, mas é um fato, que vários pesquisadores apontam, a existência de muitos problemas no ensino da astronomia. Com o propósito de minimizar algumas dessas deficiências foi realizado um trabalho de pesquisa com a utilização de questionários pré e pós pesquisa, para tanto foi desenvolvido um Curso de Extensão Universitária para professores da Diretoria de Ensino Regional (DE) que abrange Mauá, Ribeirão Pires e Rio Grande da Serra (no Estado de São Paulo) com os seguintes objetivos: levantar concepções alternativas; subsidiar os professores por meio de palestras, debates e workshops, e verificar o sucesso da aprendizagem após o curso, adotando-se como referência, para a análise dos resultados, os dicionários de Língua Portuguesa (FERREIRA, 2004) e Enciclopédico de Astronomia e Astronáutica (MOURĀO, 1995). Portanto, dezesseis questões foram aplicadas antes e após o curso, assim pode-se verificar após a pesquisa que 100,0% dos professores sabiam os nomes das fases da Lua, 97,0% entenderam que o Sistema Solar é composto por oito planetas, 78,1% foram capazes de explicar como ocorre um eclipse lunar, um eclipse solar e um solstício, 72,7% sabiam como explicar a ocorrência das estações do ano; 64,5% explicaram corretamente a ocorrência do equinócio, 89,7% foram capazes de definir adequadamente o termo cometa; 63,6% definiram asteróide, 54,5% meteoro, 58,1% galáxia, e 42,4% planeta. Os resultados obtidos indicam uma aprendizagem significativa por parte dos participantes.

  11. Population genetics of the porB gene of Neisseria gonorrhoeae: different dynamics in different homology groups.

    PubMed

    Posada, D; Crandall, K A; Nguyen, M; Demma, J C; Viscidi, R P

    2000-03-01

    The porB locus codes for the major outer membrane protein of Neisseria gonorrhoeae. Alleles of this locus have been assigned to two homology groups based on close sequence and immunological relationships and are designated as either PIA or PIB. Several population parameters were estimated and compared among these two groups using a data set of 22 PIA sequences and 91 PIB sequences obtained from diverse geographic localities and from time periods spanning approximately 50 years. Recombination appears to be extensive in the porB gene. While the recombination rates are similar for the PIA and PIB sequences, the relative contribution of recombination to genetic diversity is higher for the PIA sequences. Alleles belonging to the PIB group show greater genetic diversity than do those in the PIA group. Although phylogenetic analysis did not reveal temporal or geographic clustering of sequences, estimates of gene flow and the fixation index suggested that PIB sequences exhibit population substructure based on geographic locality. Selection acts in these homology groups in a different way. While positive Darwinian selection is the dominant force driving the evolution of the PIA sequences, purifying selection operates also on the PIB sequences. These differences may be attributable to the greater propensity of PIA strains, as compared with PIB strains, to cause disseminated gonococcal infection, which would expose the former to intense selection pressure from the host immune system. The molecular evolution of Neisseria gonorrhoeae seems to be driven by the simultaneous action of selection and recombination, but under different rates and selection pressures for the PIA and PIB homology groups.

  12. Immunogenicity and reactogenicity in UK infants of a novel meningococcal vesicle vaccine containing multiple class 1 (PorA) outer membrane proteins.

    PubMed

    Cartwright, K; Morris, R; Rümke, H; Fox, A; Borrow, R; Begg, N; Richmond, P; Poolman, J

    1999-06-01

    The development of effective vaccines against serogroup B meningococci is of great public health importance. We assessed a novel genetically engineered vaccine containing six meningococcal class 1 (PorA) outer membrane proteins representing 80% of prevalent strains in the UK. 103 infants were given the meningococcal vaccine at ages 2, 3 and 4 months with routine infant immunisations, with a fourth dose at 12-18 months. The vaccine was well tolerated. Three doses evoked good immune responses to two of six meningococcal strains expressing PorA proteins contained in the vaccine. Following a fourth dose, larger bactericidal responses to all six strains were observed, suggesting that the initial course had primed memory lymphocytes and revaccination stimulated a booster response. This hexavalent PorA meningococcal vaccine was safe and evoked encouraging immune responses in infants. Vaccines of this type warrant further development and evaluation. PMID:10418910

  13. Spatial patterns of chemical contamination (metals, PAHs, PCBs, PCDDs/PCDFS) in sediments of a non-industrialized but densely populated coral atoll/small island state (Bermuda).

    PubMed

    Jones, Ross J

    2011-06-01

    There is a recognized dearth of standard environmental quality data in the wider Caribbean area, especially on coral atolls/small island states. Extensive surveys of sediment contamination (n=109 samples) in Bermuda revealed a wide spectrum of environmental quality. Zinc and especially copper levels were elevated at some locations, associated with boating (antifouling paints and boatyard discharges). Mercury contamination was surprisingly prevalent, with total levels as high as 12mg kg(-1)DW, although methyl mercury levels were quite low. PAH, PCB and PCDD/PCDF contamination was detected a several hotspots associated with road run-off, a marine landfill, and a former US Naval annexe. NOAA sediment quality guidelines were exceeded at several locations, indicating biological effects are possible, or at some locations probable. Overall, and despite lack of industrialization, anthropogenic chemicals in sediments of the atoll presented a risk to benthic biodiversity at a number of hotspots suggesting a need for sediment management strategies. PMID:21549399

  14. RELATIVE POTENCY BASED ON HEPATIC ENZYME INDUCTION PREDICTS IMMUNOSUPPRESSIVE EFFECT OF A MIXTURE OF POLYCHLORINATED DIBENZO-P-DIOXINS (PCDDS), DIBENZOFURANS (PCDFS) AND BIPHENYLS (PCBS)

    EPA Science Inventory

    ABSTRACT
    ). Mixture (MIX)-1 contained TCDD , 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-pentachlorodibenzofuran (1-PeCDF), 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF), and 1,2,3,4,6,7,8,9-octachlorodibenzofuran (OCDF). MIX-2 was prepared by adding PCBs to MIX-1, the P...

  15. Polychlorinated dibenzo-p-dioxins, furans, and biphenyls (PCDDs/PCDFs and PCBs) in breast milk and early childhood growth and IGF1.

    PubMed

    Wohlfahrt-Veje, Christine; Audouze, Karine; Brunak, Søren; Antignac, Jean Philippe; le Bizec, Bruno; Juul, Anders; Skakkebæk, Niels E; Main, Katharina Maria

    2014-01-01

    Experimental studies have shown that dioxin-like chemicals may interfere with aspects of the endocrine system including growth. However, human background population studies are, however, scarce. We aimed to investigate whether early exposure of healthy infants to dioxin-like chemicals was associated with changes in early childhood growth and serum IGF1. In 418 maternal breast milk samples of Danish children (born 1997-2001) from a longitudinal cohort, we measured polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls (pg or ng/g lipid) and calculated total toxic equivalent (total TEQ). SDS and SDS changes over time (ΔSDS) were calculated for height, weight, BMI, and skinfold fat percentage at 0, 3, 18, and 36 months of age. Serum IGF1 was measured at 3 months. We adjusted for confounders using multivariate regression analysis. Estimates (in parentheses) correspond to a fivefold increase in total TEQ. TEQ levels in breast milk increased significantly with maternal age and fish consumption and decreased with maternal birth year, parity, and smoking. Total TEQ was associated with lower fat percentage (-0.45 s.d., CI: -0.89; -0.04), non-significantly with lower weight and length at 0 months, accelerated early height growth (increased ΔSDS) (ΔSDS 0-18 months: +0.77 s.d., CI: 0.34; 1.19) and early weight increase (ΔSDS 0-18: +0.52 s.d., CI: 0.03; 1.00), and increased IGF1 serum levels at 3 months (+13.9 ng/ml, CI: 2.3; 25.5). Environmental exposure to dioxin-like chemicals was associated with being skinny at birth and with higher infant levels of circulating IGF1 as well as accelerated early childhood growth (rapid catch-up growth).

  16. Emissions of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) to air from waste incinerators and high thermal processes in India.

    PubMed

    Thacker, Neeta; Sheikh, Javed; Tamane, S M; Bhanarkar, Anil; Majumdar, Deepanjan; Singh, Kanchan; Chavhan, Chatrapati; Trivedi, Jitendra

    2013-01-01

    This study investigated dioxins and dioxin-like polychlorinated biphenyls in gasses emitted from waste incinerators and thermal processes in central and western parts of India. The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs) ranged from 0.0070 to 26.8140 ng toxicity equivalent (TEQ)/Nm(3), and those of dioxin-like polychlorinated biphenyls (PCBs) ranged from 0.0001 × 10(-1) to 0.0295 ng TEQ/Nm(3). The characteristics of mean PCDD/F I-TEQ concentration and congener profiles were studied over all the samples of air. In particular, a pattern consisting of a low proportion of dioxin-like PCBs and high proportion of PCDDs/DFs was common for all the samples from incinerators and high-temperature processes.

  17. Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in Finnish semi-domesticated reindeer (Rangifer tarandus tarandus L.).

    PubMed

    Suutari, Anniina; Ruokojärvi, Päivi; Kiviranta, Hannu; Verta, Matti; Korhonen, Markku; Nieminen, Mauri; Laaksonen, Sauli

    2011-02-01

    To explore the concentrations and dynamics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Finnish semi-domesticated reindeer (Rangifer tarandus tarandus L.) the reindeer milk and tissue samples were collected from the sub-arctic northern Finland. Reindeer milk's PCB sum (1.20 ng g(-1) wet weight) and PCDD/F sum (0.70 pg g(-1) ww) in autumn were higher than in summer (PCBs 0.50 ng g(-1) ww and PCDD/Fs 0.20 pg g(-1) ww). The mean fat content in autumn milk (26%) was significantly higher than in summer (10%). Concentrations in reindeer milk were generally far below 50% of that in adult reindeer body burden. However, the bioaccumulation factors were multiple in milk/reindeer calf ratio and that aroused the question of other important exposure routes than lactation. The muscle and liver of reindeer calves had higher PCDD/F and PCB concentrations than adult animals that possibly indicate the significance of transfer of these compounds from dam to calf through lactation and placenta. However, PBDE concentrations were higher in adult reindeer, especially in liver. In addition, reindeer liver seems to have a special feature to collect highly toxic PCDD/Fs, although the PCB sum concentrations (range from 0.33 to 1.69 ng g(-1) wet weight) were clearly higher than the sums of PCDD/Fs (range from 3.78 to 39.2 pg g(-1) ww). Stillborn reindeer calves represented individuals who had got their PCDD/F, PCB and PBDE load only via the placenta. Concentrations in muscle and brown adipose tissue samples did not indicate dependency on fat content. Obviously effective placental transfer of PCBs and PBDEs from reindeer dam to foetus was seen in this study.

  18. Crystallization and preliminary X-ray analysis of the C-terminal fragment of PorM, a subunit of the Porphyromonas gingivalis type IX secretion system.

    PubMed

    Stathopulos, Julien; Cambillau, Christian; Cascales, Eric; Roussel, Alain; Leone, Philippe

    2015-01-01

    PorM is a membrane protein involved in the assembly of the type IX secretion system (T9SS) from Porphyromonas gingivalis, a major bacterial pathogen responsible for periodontal disease in humans. The periplasmic domain of PorM was overexpressed in Escherichia coli and purified. A fragment of the purified protein was obtained by limited proteolysis. Crystals of this fragment belonged to the tetragonal space group P4(3)2(1)2. Native and MAD data sets were recorded to 2.85 and 3.1 Å resolution, respectively, using synchrotron radiation. PMID:25615973

  19. "Estudio tribologico de aceros para moldes. Aplicacion al moldeo por inyeccion de polibutilentereftalato reforzado con fibra de vidrio"

    NASA Astrophysics Data System (ADS)

    Martinez Mateo, Isidoro Jose

    Mould materials for injection moulding of polymers and polymer-matrix composites represent a relevant industrial economic sector due to the large quantity of pieces and components processed. The material selection for mould manufacturing, its composition and heat treatment, the hardening procedures and machining and finishing processes determine the service performance and life of the mould. In the first part of the present study, the relationship between the hardness and microstructure and the wear resistance of mould steels from large blocks has been studied by pin-on-disc tests, studying the main wear mechanisms. In order to determine the surface damage on mould steels under real injection conditions, different commercial steels have been studied by measuring the variation of surface roughness with the number of injected pieces with different reinforcement percentages and different mould geometries, by using optical profilometry and scanning electron microscopy techniques. It was important to determine the variation of surface roughness of the moulded pieces with the number of injection operations. The materials used were polybutyleneterephthalate pure and reinforced with either 20% or 50% glass fibre. For the different mould designs, the evolution of the glass fibre orientation with injection flow has been determined by image analysis and related to roughness changes and surface damage, both of the composite parts and of the mould steel surface. Finally, the abrasion resistance of the composite parts has been studied by scratch tests as a function of the number of injected parts and of the scratch direction with respect to injection flow and glass fibre orientation. Los materiales para moldes de inyeccion de polimeros y materiales compuestos representan un sector economicamente muy relevante debido al gran aumento del numero de componentes fabricados a partir de materiales polimericos obtenidos mediante moldeo por inyeccion. La seleccion del material para la

  20. Palivizumab outcomes registry data from Spain: Infección Respiratoria Infantil por Virus Respiratorio Sincitial (IRIS) Study Group.

    PubMed

    Carbonell-Estrany, Xavier

    2003-02-01

    Respiratory syncytial virus (RSV) is the leading cause of lower respiratory illness in children <2 years of age. Severe RSV infection requiring hospitalization is linked to gestational age, chronic cardiopulmonary conditions and immunosuppression. The Infección Respiratoria Infantil por Virus Respiratorio Sincitial (IRIS) Study group in Spain conducted two pivotal epidemiologic studies establishing that serious RSV illness among premature infants was responsible for high rehospitalization rates (approximately 13%). RSV lower respiratory tract illness also correlated with prolonged hospital stay and more intensive care unit admissions. In Europe recent availability of palivizumab, a humanized monoclonal antibody to RSV, is a major therapeutic advancement directed against prevention of lower respiratory tract infection secondary to this viral pathogen. To ensure proper and optimal usage of palivizumab, the IRIS group, in conjunction with the Spanish Neonatology Group, developed prophylaxis guidelines for neonates. Palivizumab prophylaxis is strongly recommended in premature infants < or =28 weeks gestation or those affected with chronic lung disease. Additionally, palivizumab is recommended for infants with a gestational age of 29 to 32 weeks, without evidence of chronic lung disease and who are <6 months old at the onset of the RSV season. It was thought that slightly older premature infants (33 to 35 weeks gestational age) should be assessed on an individual basis to determine whether prophylaxis is warranted. The IRIS Study Group is currently determining the effectiveness of these recommendations by measuring the incidence of RSV-related hospital admissions in infants born at < or =32 weeks gestational age who are receiving palivizumab prophylaxis.

  1. Double-locus sequence typing using porA and peb1A for epidemiological studies of Campylobacter jejuni.

    PubMed

    Ahmed, Monir U; Dunn, Louise; Valcanis, Mary; Hogg, Geoff; Ivanova, Elena P

    2014-03-01

    Campylobacter jejuni is the leading cause of foodborne bacterial gastroenteritis worldwide. Bacterial typing schemes play an important role in epidemiological investigations to trace the source and route of transmission of the infectious agent by identifying outbreak and differentiating among sporadic infections. In this study, a double-locus sequence typing (DLST) scheme for C. jejuni based on concatenated partial sequences of porA and peb1A genes is proposed. The DLST scheme was validated using 50 clinical and environmental C. jejuni strains isolated from human (C5, H, H15-H19), chicken (CH1-CH15), water (W2-W17), and ovine samples (OV1-OV6). The scheme was found to be highly discriminatory (discrimination index [DI]=0.964) and epidemiologically concordant based on C. jejuni strains studied. The DLST showed discriminatory power above 0.95 and excellent congruence to multilocus sequence typing and can be recommended as a rapid and low-cost typing scheme for epidemiological investigation of C. jejuni. It is suggested that the DLST scheme is suitable for identification of outbreak strains and differentiation of the sporadic infection strains.

  2. Saturating mutagenesis of an essential gene: a majority of the Neisseria gonorrhoeae major outer membrane porin (PorB) is mutable.

    PubMed

    Chen, Adrienne; Seifert, H Steven

    2014-02-01

    The major outer membrane porin (PorB) of Neisseria gonorrhoeae is an essential protein that mediates ion exchange between the organism and its environment and also plays multiple roles in human host pathogenesis. To facilitate structure-function studies of porin's multiple roles, we performed saturating mutagenesis at the porB locus and used deep sequencing to identify essential versus mutable residues. Random mutations in porB were generated in a plasmid vector, and mutant gene pools were transformed into N. gonorrhoeae to select for alleles that maintained bacterial viability. Deep sequencing of the input plasmid pools and the output N. gonorrhoeae genomic DNA pools identified mutations present in each, and the mutations in both pools were compared to determine which changes could be tolerated by the organism. We examined the mutability of 328 amino acids in the mature PorB protein and found that 308 of them were likely to be mutable and that 20 amino acids were likely to be nonmutable. A subset of these predictions was validated experimentally. This approach to identifying essential amino acids in a protein of interest introduces an additional application for next-generation sequencing technology and provides a template for future studies of both porin and other essential bacterial genes.

  3. Informe a la nación indica que los índices de muertes por cáncer siguen bajando

    Cancer.gov

    Los índices de mortalidad por todos los cánceres combinados para hombres, mujeres y niños siguieron bajando en Estados Unidos entre 2004 y 2008, según el Informe Anual a la Nación sobre el Estado del Cáncer de 1975 a 2008. El índice general de diagnóstico

  4. El proceso hacia la integracion de la equidad por genero al curriculo.(The Process of the Integration of Gender Equity in the Curriculum.)

    ERIC Educational Resources Information Center

    Rivera-Bermudez, Carmen D.

    "El Proyecto Colaborativo de Equidad por Genero en la Educacion," or the Collaborative Project for Gender Equity in Education, was undertaken in Puerto Rico between 1990 and 1992 to study how to facilitate the integration of gender equity themes in the curriculum through the direct action of participating teachers. A study examined the attitudes…

  5. Cell Growth Defect Factor1/CHAPERONE-LIKE PROTEIN OF POR1 Plays a Role in Stabilization of Light-Dependent Protochlorophyllide Oxidoreductase in Nicotiana benthamiana and Arabidopsis[C][W

    PubMed Central

    Lee, Jae-Yong; Lee, Ho-Seok; Song, Ji-Young; Jung, Young Jun; Reinbothe, Steffen; Park, Youn-Il; Lee, Sang Yeol; Pai, Hyun-Sook

    2013-01-01

    Angiosperms require light for chlorophyll biosynthesis because one reaction in the pathway, the reduction of protochlorophyllide (Pchlide) to chlorophyllide, is catalyzed by the light-dependent protochlorophyllide oxidoreductase (POR). Here, we report that Cell growth defect factor1 (Cdf1), renamed here as CHAPERONE-LIKE PROTEIN OF POR1 (CPP1), an essential protein for chloroplast development, plays a role in the regulation of POR stability and function. Cdf1/CPP1 contains a J-like domain and three transmembrane domains, is localized in the thylakoid and envelope membranes, and interacts with POR isoforms in chloroplasts. CPP1 can stabilize POR proteins with its holdase chaperone activity. CPP1 deficiency results in diminished POR protein accumulation and defective chlorophyll synthesis, leading to photobleaching and growth inhibition of plants under light conditions. CPP1 depletion also causes reduced POR accumulation in etioplasts of dark-grown plants and as a result impairs the formation of prolamellar bodies, which subsequently affects chloroplast biogenesis upon illumination. Furthermore, in cyanobacteria, the CPP1 homolog critically regulates POR accumulation and chlorophyll synthesis under high-light conditions, in which the dark-operative Pchlide oxidoreductase is repressed by its oxygen sensitivity. These findings and the ubiquitous presence of CPP1 in oxygenic photosynthetic organisms suggest the conserved nature of CPP1 function in the regulation of POR. PMID:24151298

  6. Estimaciones de Prevalencia del VIH por Género y Grupo de Riesgo en Tijuana, México: 2006

    PubMed Central

    Iñiguez-Stevens, Esmeralda; Brouwer, Kimberly C.; Hogg, Robert S.; Patterson, Thomas L.; Lozada, Remedios; Magis-Rodriguez, Carlos; Elder, John P.; Viani, Rolando M.; Strathdee, Steffanie A.

    2010-01-01

    OBJETIVO Estimar la prevalencia del VIH en adultos de 15-49 años de edad en Tijuana, México - en la población general y en subgrupos de riesgo en el 2006. METODOS Se obtuvieron datos demográficos del censo Mexicano del 2005, y la prevalencia del VIH se obtuvo de la literatura. Se construyó un modelo de prevalencia del VIH para la población general y de acuerdo al género. El análisis de sensibilidad consistió en estimar errores estándar del promedio-ponderado de la prevalencia del VIH y tomar derivados parciales con respecto a cada parámetro. RESULTADOS La prevalencia del VIH es 0.54%(N = 4,347) (Rango: 0.22%–0.86%, (N = 1,750–6,944)). Esto sugiere que 0.85%(Rango: 0.39%–1.31%) de los hombres y 0.22%(Rango: 0.04%–0.40%) de las mujeres podrían ser VIH-positivos. Los hombres que tienen sexo con hombres (HSH), las trabajadoras sexuales usuarias de drogas inyectables (MTS-UDI), MTS-noUDI, mujeres UDI, y los hombres UDI contribuyeron las proporciones más elevadas de personas infectadas por el VIH. CONCLUSIONES El número de adultos VIH-positivos entre subgrupos de riesgo en la población de Tijuana es considerable, marcando la necesidad de enforcar las intervenciones de prevención en sus necesidades específicas. El presente modelo estima que hasta 1 en cada 116 adultos podrían ser VIH-positivos. PMID:19685824

  7. Los índices de mortalidad por cáncer de pulmón siguen en descenso y contribuyen a la continua reducc

    Cancer.gov

    El Informe Anual a la Nación sobre el Estado del Cáncer (1975 a 2010), mostró un descenso más acelerado que en años anteriores de los índices de mortalidad por cáncer de pulmón. También contiene una sección especial que destaca los efectos significativos

  8. La doctora Amelie Ramírez y la investigación de desigualdades de salud por cáncer en la comunidad la

    Cancer.gov

    La doctora Ramírez es la investigadora principal de Redes en Acción, un centro del programa de redes comunitarias subvencionado por el NCI que se propone reducir la incidencia del cáncer en la comunidad latina a través de una red nacional de grupos comunitarios, investigadores, agencias de salud gubernamentales y la población en general.

  9. Binding of complement factor H to PorB3 and NspA enhances resistance of Neisseria meningitidis to anti-factor H binding protein bactericidal activity.

    PubMed

    Giuntini, Serena; Pajon, Rolando; Ram, Sanjay; Granoff, Dan M

    2015-04-01

    Among 25 serogroup B Neisseria meningitidis clinical isolates, we identified four (16%) with high factor H binding protein (FHbp) expression that were resistant to complement-mediated bactericidal activity of sera from mice immunized with recombinant FHbp vaccines. Two of the four isolates had evidence of human FH-dependent complement downregulation independent of FHbp. Since alternative complement pathway recruitment is critical for anti-FHbp bactericidal activity, we hypothesized that in these two isolates binding of FH to ligands other than FHbp contributes to anti-FHbp bactericidal resistance. Knocking out NspA, a known meningococcal FH ligand, converted both resistant isolates to anti-FHbp susceptible isolates. The addition of a nonbactericidal anti-NspA monoclonal antibody to the bactericidal reaction also increased anti-FHbp bactericidal activity. To identify a role for FH ligands other than NspA or FHbp in resistance, we created double NspA/FHbp knockout mutants. Mutants from both resistant isolates bound 10-fold more recombinant human FH domains 6 and 7 fused to Fc than double knockout mutants prepared from two sensitive meningococcal isolates. In light of recent studies showing functional FH-PorB2 interactions, we hypothesized that PorB3 from the resistant isolates recruited FH. Allelic exchange of porB3 from a resistant isolate to a sensitive isolate increased resistance of the sensitive isolate to anti-FHbp bactericidal activity (and vice versa). Thus, some PorB3 variants functionally bind human FH, which in the presence of NspA enhances anti-FHbp resistance. Combining anti-NspA antibodies with anti-FHbp antibodies can overcome resistance. Meningococcal vaccines that target both NspA and FHbp are likely to confer greater protection than either antigen alone.

  10. Obtención de la curva de luz en la ocultación de 35 Sgr por Júpiter el 6 de marzo de 1996

    NASA Astrophysics Data System (ADS)

    Paolantonio, S.; Duffard, R.; Carranza, G.

    La ocultación de la estrella de quinta magnitud 35 Sgr por Júpiter, se produjo el 6 de Marzo de 1996 a las 13 hs. TU. El objetivo era medir el cambio del flujo de la estrella en el ingreso y egreso por el limbo del planeta. Con estos datos se pueden determinar parámetros físicos del planeta (radio, eccentricidad) y de su atmósfera (escala de altura, temperatura, densidad, presión) Para lograr ésto se programó la cámara CCD TH 7896 1024 x 1025 instalada en el telescopio de 1.54 m de Bosque Alegre con el objetivo de lograr 2 imágenes por segundo. De esta forma se obtuvieron 2100 imágenes de la inmersión y otras tantas de la emersión. Hubo que tener grandes precauciones para evitar la saturación del CCD ya que la observación se realizó de día. En este momento las imágenes se encuentran en el Department of Planetary Sciences, Lunar and Planetary Laboratory, University of Arizona, para su reducción.

  11. Immunogenicity studies with a genetically engineered hexavalent PorA and a wild-type meningococcal group B outer membrane vesicle vaccine in infant cynomolgus monkeys.

    PubMed

    Rouppe van der Voort, E; Schuller, M; Holst, J; de Vries, P; van der Ley, P; van den Dobbelsteen, G; Poolman, J

    2000-01-31

    The immunogenicity of two meningococcal outer membrane vesicle (OMV) vaccines, namely the Norwegian wild-type OMV vaccine and the Dutch hexavalent PorA OMV vaccine, were examined in infant cynomolgus monkeys. For the first time, a wild-type- and a recombinant OMV vaccine were compared. Furthermore, the induction of memory and the persistence of circulating antibodies were measured. The Norwegian vaccine contained all four classes of major outer membrane proteins (OMP) and wild-type L3/L8 lipopolysaccharide (LPS). The Dutch vaccine consisted for 90% of class 1 OMPs, had low expression of class 4 and 5 OMP, and GalE LPS. Three infant monkeys were immunised with a human dose at the age of 1.5, 2.5 and 4.5 months. Two monkeys of each group received a fourth dose at the age of 11 months. In ELISA, both OMV vaccines were immunogenic and induced booster responses, particularly after the fourth immunisation. The Norwegian vaccine mostly induced sero-subtype P1.7,16 specific serum bactericidal antibodies (SBA), although some other SBA were induced as well. The antibody responses against P1.7,16, induced by the Norwegian vaccine, were generally higher than for the Dutch vaccine. However, the Dutch vaccine induced PorA specific SBA against all six sero-subtypes included in the vaccine showing differences in the magnitude of SBA responses to the various PorAs. PMID:10618530

  12. Astronomy in the Classroom: Why? (Spanish Title: Astronomía en la Clase: ¿Por Qué?) Astronomia na Sala de Aula: Por Quê?

    NASA Astrophysics Data System (ADS)

    Daros Gama, Leandro; Bagdonas Henrique, Alexandre

    2010-07-01

    There are many discussions about the relevance of the topics covered in classes. One subject in particular is the focus of this essay: astronomy. In what sense and to what extent it would be worth to teach it in science or other kind of classes? In this paper we discuss some aspects of the advantages of dealing with this area of knowledge in schools, taking into account the epistemological and axiological dimensions of astronomy, in light of the vision of science as an intelligent dialogue with the world (Bachelard), in addition to the "problematization" knowledge of Paulo Freire. We propose that in fact the Astronomy does not need to be seen as just a new set of contents to be taught, but appears as a set of motivational contents for historical-philosophical discussions, and permit the discussion of concepts of other disciplines. Numerosas discusiones se están llevando a cabo acerca de la pertinencia de los temas tradicionalmente tratados en las clases. Uno de los temas, en particular, es el foco de este ensayo: la astronomía. ¿En qué sentido y en qué medida sería conveniente tratarla en clase, ya sea en clases de ciencias naturales, específicamente en las de astronomía o asignaturas afines? Elaboramos en este artículo algunos aspectos de las ventajas de tratar esta área del conocimiento en las escuelas, teniendo en cuenta las dimensiones epistemológica y axiológica de la astronomía, a la luz de la visión de la ciencia como un diálogo inteligente con el mundo (Bachelard), además de la propuesta del conocimiento "problematizador" de Paulo Freire. Proponemos que en realidad la astronomía no tiene por qué ser vista sólo como un nuevo conjunto de contenidos que se enseñan, sino que aparece como un conjunto de temas de motivación para el debate histórico-filosófico y para permitir la discusión de los conceptos típicos de otras disciplinas. Muitas discussões vêm acontecendo sobre a relevância dos temas abordados em sala de aula. Um tema, em

  13. Pincharse sin infectarse: estrategias para prevenir la infección por el VIH y el VHC entre usuarios de drogas inyectables

    PubMed Central

    MATEU-GELABERT, P.; FRIEDMAN, S.; SANDOVAL, M.

    2011-01-01

    Resumen Objetivo Desde principios de los noventa, en la ciudad de Nueva York se han implementado con éxito programas para reducir la incidencia del virus de la inmunodeficiencia humana (VIH) y, en menor medida, del virus de la hepatitis C (VHC). A pesar de ello, aproximadamente el 70% de los usuario de drogas inyectables (UDI) están infectados por el VHC. Queremos investigar cómo el 30% restante se las ha arreglado para no infectarse. El Staying safe (nombre original del estudio) explora los comportamientos y mecanismos que ayudan a evitar la infección por el VHC y el VIH a largo plazo. Material y métodos Hemos utilizado el concepto de «desviación positiva» aplicado en otros campos de salud pública. Estudiamos las estrategias, prácticas y tácticas de prevención de aquellos UDI que, viviendo en contextos de alta prevalencia, se mantienen sin infectar por VIH y el VHC, a pesar de haberse inyectado heroína durante años. Los resultados preliminares presentados en este artículo incluyen el análisis de las entrevistas realizadas a 25 UDI (17 doble negativos, 3 doble positivos y 5 con infección por el VHC y sin infección por el VIH). Se usaron entrevistas semiestructuradas que exploraban con detalle la historia de vida de los sujetos, incluyendo su consumo de drogas, redes sociales, contacto con instituciones, relaciones sexuales y estrategias de protección y vigilancia. Resultados La intencionalidad es importante para no infectarse, especialmente durante períodos de involución (períodos donde hay un deterioro económico y/o social que llevan al que se inyecta a situaciones de mayor riesgo). Presentamos tres dimensiones independientes de intencionalidad que conllevan comportamientos que pueden ayudar a prevenir la infección: a) evitar «el mono» (síntomas de abstención) asegurando el acceso a la droga; b) «llevarlo bien» para no convertirse en un junkie y así evitar la «muerte social» y la falta de acceso a los recursos, y c) seguir sin

  14. A Fast Real-Time Polymerase Chain Reaction Method for Sensitive and Specific Detection of the Neisseria gonorrhoeae porA Pseudogene

    PubMed Central

    Hjelmevoll, Stig Ove; Olsen, Merethe Elise; Sollid, Johanna U. Ericson; Haaheim, Håkon; Unemo, Magnus; Skogen, Vegard

    2006-01-01

    Ever since the advent of molecular methods, the diagnostics of Neisseria gonorrhoeae has been troubled by false negative and false positive results compared with culture. Commensal Neisseria species and Neisseria meningitidis are closely related to N. gonorrhoeae and may cross-react when using molecular tests comprising too-low specificity. We have devised a real-time polymerase chain reaction (PCR), including an internal amplification control, that targets the N. gonorrhoeae porA pseudogene. DNA was automatically isolated on a BioRobot M48. Our subsequent PCR method amplified all of the different N. gonorrhoeae international reference strains (n = 34) and N. gonorrhoeae clinical isolates (n = 176) but not isolates of the 13 different nongonococcal Neisseria species (n = 68) that we tested. Furthermore, a panel of gram-negative bacterial (n = 18), gram-positive bacterial (n = 23), fungal (n = 1), and viral (n = 4) as well as human DNA did not amplify. The limit of detection was determined to be less than 7.5 genome equivalents/PCR reaction. In conclusion, the N. gonorrhoeae porA pseudogene real-time PCR developed in the present study is highly sensitive, specific, robust, rapid and reproducible, making it suitable for diagnosis of N. gonorrhoeae infection. PMID:17065426

  15. Prevalencia y factores de riesgo para infecciones del tracto urinario de inicio en la comunidad causadas por Escherichia coli productor de betalactamasas de espectro extendido en Colombia

    PubMed Central

    Blanco, Victor M.; Maya, Juan J.; Correa, Adriana; Perenguez, Marcela; Muñoz, Juan S.; Motoa, Gabriel; Pallares, Christian J.; Rosso, Fernando; Matta, Lorena; Celis, Yamile; Garzon, Martha; Villegas, y María V.

    2016-01-01

    RESUMEN Introducción Las infecciones del tracto urinario (ITU) son frecuentes en la comunidad. Sin embargo, la información de aislamientos resistentes en este contexto es limitada en Latinoamérica. Este estudio tiene como objetivo determinar la prevalencia y los factores de riesgo asociados con ITU de inicio en la comunidad (ITU-IC) causadas por Escherichia coli productor de betalactamasas de espectro extendido (BLEE) en Colombia. Materiales y métodos Entre agosto y diciembre de 2011 se realizó un estudio de casos y controles en 3 instituciones de salud de tercer nivel en Colombia. Se invitó a participar a todos los pacientes admitidos a urgencias con diagnóstico probable de ITU-IC, y se les pidió una muestra de orina. En los aislamien-tos de E. coli se realizaron pruebas confirmatorias para BLEE, susceptibilidad antibiótica, caracterización molecular (PCR en tiempo real para genes bla, repetitive element palindromic PCR [rep-PCR], multilocus sequence typing [MLST] y factores de virulencia por PCR). Se obtuvo información clínica y epidemiológica, y posteriormente se realizó el análisis estadístico. Resultados De los 2.124 pacientes seleccionados, 629 tuvieron un urocultivo positivo, en 431 de estos se aisló E. coli, 54 fueron positivos para BLEE y 29 correspondieron a CTX-M-15. La mayoría de los aislamientos de E. coli productor de BLEE fueron sensibles a ertapenem, fosfomicina y amikacina. La ITU complicada se asoció fuertemente con infecciones por E. coli productor de BLEE (OR = 3,89; IC 95%: 1,10–13,89; p = 0,03). E. coli productor de CTX-M-15 mostró 10 electroferotipos diferentes; de estos, el 65% correspondieron al ST131. La mayoría de estos aislamientos tuvieron 8 de los 9 factores de virulencia analizados. Discusión E. coli portador del gen blaCTX-M-15 asociado al ST131 sigue siendo frecuente en Colombia. La presencia de ITU-IC complicada aumenta el riesgo de tener E. coli productor de BLEE, lo cual debe tenerse en cuenta para ofrecer

  16. Neisserial porin (PorB) causes rapid calcium influx in target cells and induces apoptosis by the activation of cysteine proteases.

    PubMed Central

    Müller, A; Günther, D; Düx, F; Naumann, M; Meyer, T F; Rudel, T

    1999-01-01

    The porin (PorB) of Neisseria gonorrhoeae is an intriguing bacterial factor owing to its ability to translocate from the outer bacterial membrane into host cell membranes where it modulates the infection process. Here we report on the induction of programmed cell death after prolonged infection of epithelial cells with pathogenic Neisseria species. The underlying mechanism we propose includes translocation of the porin, a transient increase in cytosolic Ca2+ and subsequent activation of the Ca2+ dependent protease calpain as well as proteases of the caspase family. Blocking the porin channel by ATP eliminates the Ca2+ signal and also abolishes its pro-apoptotic function. The neisserial porins share structural and functional homologies with the mitochondrial voltage-dependent anion channels (VDAC). The neisserial porin may be an analogue or precursor of the ancient permeability transition pore, the putative central regulator of apoptosis. PMID:9889191

  17. Four-month outbreak of invasive meningococcal disease caused by a rare serogroup B strain, identified through the use of molecular PorA subtyping, England, 2013.

    PubMed

    Chatt, C; Gajraj, R; Hawker, J; Neal, K; Tahir, M; Lawrence, M; Gray, S J; Lucidarme, J; Carr, A D; Clark, S A; Fowler, T

    2014-01-01

    Molecular PorA subtyping provides information that increasingly requires the adaptation of standard public health approaches to outbreak management. We report an outbreak of a rare subtype of meningococcal infection not previously identified in the United Kingdom (UK). The outbreak occurred in the Warwickshire area in England between February and June 2013. Molecular subtyping allowed the identification of additional cases, prompting an enhanced public health response that included efforts to identify potential social networks that might benefit from chemoprophylaxis. It also prompted swabbing to define nasopharyngeal carriage in the focal nursery and helped explain the unusual epidemiological pattern. Without subtyping to identify a link, the additional cases would have been managed as sporadic cases in accordance with current UK guidance. PMID:25394258

  18. Concepciones y concepciones alternativas de estudiantes universitarios/as de biologia y futuros maestros/as de Ciencia de escuela secundaria sobre la teoria de evolucion biologica por seleccion natural

    NASA Astrophysics Data System (ADS)

    Morales Ramos, Egda M.

    La teoria de evolucion biologica (TEB) por seleccion natural es uno de los conceptos unificadores mas importantes del curriculo de Biologia. En Puerto Rico se han hecho pocas investigaciones que abunden sobre las concepciones y concepciones alternativas (CA) que tienen los estudiantes universitarios/as de Biologia y los maestros/as de Ciencia del nivel secundario sobre esta teoria. La politica publica educativa actual establece mediante documentos normativos como los Estandares de contenido y Expectativas de grado del Programa de Ciencias [Puerto Rico Core Standards] la ensenanza de esta teoria. Sin embargo, no se encontraron preguntas sobre la seleccion natural en los ejercicios de practica provistos por el Departamento de Educacion para las pruebas estandarizadas lo cual puede influir para que no se ensene adecuadamente. Las preguntas de investigacion fueron 1. ¿Cuales son las concepciones y concepciones alternativas de estudiantes universitarios/as y de los futuros maestros y maestras de Ciencia sobre la TEB? 2. ¿Cuales conceptos que seleccionan los estudiantes universitarios/as y los futuros maestros y maestras de Ciencia sobre la TEB coinciden con lo aceptado como valido por la comunidad cientifica? y 3. ¿Como comparan las respuestas de la prueba original. v. Entendiendo el cambio biologico que mide concepciones y CA sobre la TEB por seleccion natural, con las de la traducida al idioma espanol? Se utilizo el metodo cuantitativo con un diseno de investigacion transversal por encuesta. La tecnica principal para recopilar los datos fue una prueba con doce items, que formo parte de un instrumento para el cual se recopilaron diversas fuentes de evidencia acerca de su validez. Las muestras estuvieron formadas por 69 estudiantes de Ciencias Naturales y por 16 estudiantes futuros maestros y maestras del nivel secundario de la UPR-RP. Se utilizaron estadisticas descriptivas, analisis de Ji cuadrado y se calcularon los coeficientes alfa de Cronbach y de Spearman

  19. Population genetics of Neisseria gonorrhoeae in a high-prevalence community using a hypervariable outer membrane porB and 13 slowly evolving housekeeping genes.

    PubMed

    Pérez-Losada, Marcos; Viscidi, Raphael P; Demma, James C; Zenilman, Jonathan; Crandall, Keith A

    2005-09-01

    Baltimore, Md., is an urban community with a high prevalence of Neisseria gonorrhoeae. Due to partially protective immune responses, introduction of new strains from other host populations, and exposure of N. gonorrhoeae to antibiotics, the phenotypic and genotypic characteristics of the circulating strains can fluctuate over time. Understanding the overall genetic diversity and population structure of N. gonorrhoeae is essential for informing public health interventions to eliminate this pathogen. We studied gonococci population genetics in Baltimore by analyzing a hypervariable and strongly selected outer membrane porB gene and 13 slowly evolving and presumably neutral housekeeping genes (abcZ, adk, aroE, fumC, gdh, glnA, gnd, pdhC, pgm, pilA, ppk, pyrD, and serC) in 204 isolates collected in 1991, 1996, and 2001 from male and female patients of two public sexually transmitted diseases clinics. Genetic diversity (), recombination (C), growth (g), population structure, and adaptive selection under codon-substitution and amino acid property models were estimated and compared between these two gene classes. Estimates of the F(ST) fixation index and the chi(2) test of sequence absolute frequencies revealed significant temporal substructuring for both gene types. Baltimore's N. gonorrhoeae populations have increased since 1991 as indicated by consistent positive values of g. Female patients showed similar or lower levels of and C than male patients. Within the MLST housekeeping genes, levels of and C ranged from 0.001-0.013 and 0.000-0.018, respectively. Overall recombination seems to be the dominant force driving evolution in these populations. All loci showed amino acid sites and physicochemical properties under adaptive (or positive-destabilizing) selection, rejecting the generally assumed hypothesis of stabilizing selection for these MLST genes. Within the porB gene, protein I B showed higher and C values than protein I A. Directional positive selection possibly

  20. Bifurcación de las soluciones de vientos impulsados por radiación en estrellas Be: formación de líneas

    NASA Astrophysics Data System (ADS)

    Curé, M.; Rial, D.; Cidale, L.; Venero, R.

    Se ha estudiado la topología de la ecuación hidrodinámica no-lineal que describe el perfil de velocidades de vientos impulsados por radiación en estrellas tempranas. Al aplicar este modelo a estrellas Be se encuentra que existen dos tipos De soluciones: la estándar, que describe el viento polar, y una nueva, que describe un viento más denso y lento y que explicaría el disco que se encuentra alrededor de estos objetos. Existe una región de transición en donde ambas soluciones coexisten (bifurcación}). Ambas soluciones satisfacen en esta región las mismas condiciones de borde. Para estas dos soluciones se han obtenido los perfiles de líneas de hidrógeno del visible y del IR, resolviendo el transporte de radiación en el ``comoving frame". Para la solución estándar, se obtienen perfiles con componentes en emisión, mientras que para la nueva solución se obtienen perfiles en absorción. Se comparan cualitativamente los resultados con las observaciones.

  1. Relación masa-radio para estrellas enanas blancas y la interpretación de recientes mediciones hechas por Hipparcos

    NASA Astrophysics Data System (ADS)

    Panei, J. A.; Althaus, L. G.; Benvenuto, O. G.

    Recientes mediciones de la masa y el radio hechas por Hipparcos de las estrellas enanas blancas 40 Eri B y Procyon B (Shipman, H. & Provencal, J. - ApJ. 1998, 494, 759), sugieren un núcleo compuesto de hierro para dichas estrellas, en lugar de carbono y oxígeno como predice la teoría standard de evolución estelar. Para interpretar estas observaciones, presentamos aquí, relaciones masa-radio para configuraciones degeneradas a temperatura finita para distintas composiciones químicas centrales. Para tal fin hemos calculado secuencias evolutivas de enanas blancas utilizando el código de evolución estelar, desarrollado en el Observatorio de La Plata. Dicho código resuelve las ecuaciones de estructura y evolución estelar mediante la técnica de relajación de Henyey, y esta basado en una descripción física muy detallada y actualizada.

  2. Population pharmacokinetic approach to evaluate the effect of CYP2D6, CYP3A, ABCB1, POR and NR1I2 genotypes on donepezil clearance

    PubMed Central

    Noetzli, Muriel; Guidi, Monia; Ebbing, Karsten; Eyer, Stephan; Wilhelm, Laurence; Michon, Agnès; Thomazic, Valérie; Stancu, Ioana; Alnawaqil, Abdel-Messieh; Bula, Christophe; Zumbach, Serge; Gaillard, Michel; Giannakopoulos, Panteleimon; von Gunten, Armin; Csajka, Chantal; Eap, Chin B

    2014-01-01

    Aims A large interindividual variability in plasma concentrations has been reported in patients treated with donepezil, the most frequently prescribed antidementia drug. We aimed to evaluate clinical and genetic factors influencing donepezil disposition in a patient population recruited from a naturalistic setting. Methods A population pharmacokinetic study was performed including data from 129 older patients treated with donepezil. The patients were genotyped for common polymorphisms in the metabolic enzymes CYP2D6 and CYP3A, in the electron transferring protein POR and the nuclear factor NR1I2 involved in CYP activity and expression, and in the drug transporter ABCB1. Results The average donepezil clearance was 7.3 l h−1 with a 30% interindividual variability. Gender markedly influenced donepezil clearance (P < 0.01). Functional alleles of CYP2D6 were identified as unique significant genetic covariate for donepezil clearance (P < 0.01), with poor metabolizers and ultrarapid metabolizers demonstrating, respectively, a 32% slower and a 67% faster donepezil elimination compared with extensive metabolizers. Conclusion The pharmacokinetic parameters of donepezil were well described by the developed population model. Functional alleles of CYP2D6 significantly contributed to the variability in donepezil disposition in the patient population and should be further investigated in the context of individual dose optimization to improve clinical outcome and tolerability of the treatment. PMID:24433464

  3. Neisseria gonorrhoeae isolates with reduced susceptibility to cefixime and ceftriaxone: association with genetic polymorphisms in penA, mtrR, porB1b, and ponA.

    PubMed

    Lindberg, Robert; Fredlund, Hans; Nicholas, Robert; Unemo, Magnus

    2007-06-01

    The recent emergence and transmission of Neisseria gonorrhoeae isolates with reduced susceptibility to expanded-spectrum cephalosporins such as cefixime and ceftriaxone have been reported. The aim of this study was to determine the correlation of different polymorphisms in the penA, mtrR, porB1b (penB), and ponA genes of N. gonorrhoeae with reduced susceptibility to cefixime and ceftriaxone. Eighteen gonococcal isolates with reduced cefixime and ceftriaxone susceptibility (Cef(i)) and two susceptible isolates were characterized using serovar determination, antibiograms, N. gonorrhoeae multiantigen sequence typing (NG-MAST), and sequencing of penA, mtrR, porB1b, and ponA alleles. For the Cef(i) isolates (n = 18), the MICs of cefixime and ceftriaxone ranged between 0.032 to 0.38 mug/ml and 0.064 to 0.125 mug/ml, respectively. These isolates were assigned five different serovars and six divergent NG-MAST sequence types. Eleven isolates (61%) with higher MICs of cefixime and ceftriaxone contained a nearly identical penA mosaic allele and previously described polymorphisms in mtrR (a single nucleotide [A] deletion in the promoter), penB (mutations in porB1b encoding loop 3 of PorB1b), and ponA (ponA1 polymorphism). The remaining seven Cef(i) isolates (39%), which had somewhat lower MICs of cefixime and ceftriaxone, contained an aspartic acid insertion (Asp-345a) in PBP 2 in conjunction with alterations of 4 to 10 amino acid residues in the C-terminal region of the transpeptidase domain of penA. In conclusion, an unambiguous association between penA mosaic alleles, in conjunction with genetic polymorphisms in mtrR, porB1b, and ponA, and greater reduced susceptibility to cefixime and ceftriaxone was identified.

  4. Fuentes de variabilidad en el diagnóstico de gastritis atrófica multifocal asociada con la infección por Helicobacter pylori1

    PubMed Central

    Bravo, Luis Eduardo; Bravo, Juan Carlos; Realpe, José Luis; Zarama, Guillermo; Piazuelo, MarÍa Blanca; Correa, Pelayo

    2014-01-01

    RESUMEN Introducción El mapeo de las diferentes regiones del estómago y el número de fragmentos de mucosa gástrica disponibles para evaluación histopatológica son fuentes importantes de variación en el momento de clasificar y hacer la gradación de la gastritis crónica. Objetivos Estimar la sensibilidad del número de fragmentos de mucosa gástrica necesarios para establecer los diagnósticos de gastritis atrófica con metaplasia intestinal (MI), displasia y estado de infección por Helicobacter pylori. Además evaluar la variabilidad intra-observador en la clasificación de estas lesiones precursoras del cáncer gástrico. Materiales y métodos En una cohorte de 6 años de seguimiento se evaluaron 1,958 procedimientos de endoscopia realizados por dos gastroenterólogos. En cada procedimiento y de cada participante se obtuvieron 5 biopsias de mucosa gástrica que representaban antro, incisura angularis y cuerpo. Un único patólogo hizo la interpretación histológica de las 5 biopsias y proporcionó un diagnóstico definitivo global que se utilizó como patrón de referencia. Cada fragmento de mucosa gástrica examinado condujo a un diagnóstico individual para cada biopsia que se comparó con el patrón de referencia. La variabilidad intra-observador se evaluó en 127 personas que corresponden a una muestra aleatoria de 20% del total de endoscopias hechas a los 72 meses de seguimiento. Resultados La sensibilidad del diagnóstico de MI y displasia gástrica aumentó de manera significativa con el número de fragmentos de mucosa gástrica evaluados El sitio anatómico de mayor sensibilidad para el diagnóstico de MI y displasia fue la incisura angularis. Para descubrir H. pylori se logró alta sensibilidad con el estudio de un solo fragmento de mucosa gástrica (95.9%) y fue independiente del sitio de obtención de la biopsia. El acuerdo intra-observador para el diagnóstico de gastritis crónica fue 86.1% con valor kappa de 0.79 IC 95% (0.76-0.85). Las

  5. National Dioxin Air Monitoring Network (Ndamn) Report of the Results of Atmospheric Measurements of Pcdds, Pcdfs, and Dioxin-Like PCBs in Rural and Remote Areas of the U.S. from June 1998 Through November 2004

    EPA Science Inventory

    Cover of the EPA Dioxin-like Compounds 2013 Final Report In 1998, the U.S. Environmental Protection Agency (U.S. EPA) established the Nation...

  6. DEVELOPMENT OF A REFINED DATABASE OF RELATIVE POTENCY ESTIMATES TO FACILITATE BETTER CHARACTERIZATION OF VARIABILITY AND UNCERTAINTY IN THE CURRENT MAMMALIAN TEFS FOR PCDDS, PCDFS, AND DIOXIN-LIKE PCBS

    EPA Science Inventory

    The toxic equivalency factor (TEF) approach has been widely accepted as the most feasible and plausible method presently available for evaluating potential health risks associated with exposure to mixtures of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofuran...

  7. Occurrence, variability and human exposure to Polychlorinated Dibenzo-p-dioxins (PCDDs), Polychlorinated Dibenzofurans (PCDFs) and Dioxin-Like Polychlorinated Biphenyls (DL-PCBs) in dairy products from Chile during the 2011-2013 survey.

    PubMed

    Pizarro-Aránguiz, N; Galbán-Malagón, C J; Ruiz-Rudolph, P; Araya-Jordan, C; Maddaleno, A; San Martin, B

    2015-05-01

    Levels, congener profiles of PCDD/Fs, DL-PCBs and human exposure for these xenobiotics never have been reported in Chile. For that purpose 102 raw cow milk samples were collected from seven different regions of Chile during 2011 until 2013. The highest mean level for PCDD/Fs, corresponds to 0.32 pg WHO-TEQ2005 g(-1) fat (2012) and for DL-PCBs 0.17 pg WHO-TEQ2005 g(-1) fat (2011), using the upper bound approach. Penta and tetra chlorinated congeners dominated PCDD/Fs profiles in a WHO-TEQ2005 basis during the survey. In the case of DL-PCBs, PCB 126 dominated the profiles with 89%. Statistical analysis showed significant difference among years only in DL-PCBs residues. Also dietary intake was estimated, and the highest level for total sum of PCDD/Fs and DL-PCBs for adult was 0.16 pg WHO-TEQ kg(-1) b.w d(-1) (2011) and for children correspond to 0.65 pg WHO-TEQ kg(-1) b.wd(-1) (2011). Concentrations and dietary intake for the studied compounds in milk and butter samples were below international and national regulations.

  8. Daily intake of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/PCDFs) in foodstuffs consumed in Tarragona, Spain: a review of recent studies (2001-2003) on human PCDD/PCDF exposure through the diet.

    PubMed

    Bocio, Ana; Domingo, Jose L

    2005-01-01

    Concentrations of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were measured in foodstuffs randomly acquired in various locations of Tarragona County (Catalonia, Spain) in September 2002. A total of 36 composite samples, belonging to various food groups (vegetables, fruits, meat and meat products, fish and seafood, cereals, pulses, milk, dairy products, eggs, and oils and fats) were analyzed by high-resolution gas chromatography/high-resolution mass spectrometry. The dietary intake of PCDD/Fs was subsequently determined. For calculations, recent data on consumption of the selected food items were used. Total dietary intake of PCDD/Fs for the general population of Tarragona County was estimated to be 59.6 pg I-TEQ/day (63.8 pg WHO-TEQ/day). Fish and seafood (33.7%), oils and fats (15.3%), cereals (14.4%), and dairy products (13.7%) were the most important contributors to this intake. This PCDD/F intake is notably lower than the intake estimated in 1998 for the same geographical area, 210.1 pg I-TEQ/day. The current PCDD/F dietary intake is below the tolerable intake range of 1-4 pg TEQ/kg body weight/day established by the WHO in 1998. Finally, the current intake is compared with the dietary intakes of PCDD/Fs recently (2001-2003) reported for a number of regions and countries.

  9. Estudio teórico de la desorción de Na y K de SiO2 estimulada por la acción de fotones o electrones

    NASA Astrophysics Data System (ADS)

    Domínguez Ariza, D.; López, N.; Illas, F.; Pacchioni, G.; Madey, T. E.

    Se ha estudiado el mecanismo de generación de sodio y potasio atómico a partir de muestras de SiO2 utilizando cálculos basados tanto en la teoría del funcional de la densidad como en métodos post-Hartree Fock, así como en el método de cluster para modelar el sólido. Como consecuencia del estudio se han propuesto distintos caminos posibles para la desorción, estimulada por la acción de fotones o electrones, de sodio y potasio desde el óxido de silicio, proporcionando por lo tanto una explicación a la atmósfera tenue de sodio y potasio de La Luna.

  10. Long-term RNA persistence of porcine rubulavirus (PorPV-LPMV) after an outbreak of a natural infection: the detection of viral mRNA in sentinel pigs suggests viral transmission.

    PubMed

    Cuevas-Romero, S; Hernández-Baumgarten, E; Kennedy, S; Hernández-Jáuregui, P; Berg, M; Moreno-López, J

    2014-08-01

    The persistence of porcine rubulavirus (PorPV-LPMV) in five pigs that had survived an outbreak of a natural infection was determined. After the resolution of the outbreak, each animal was housed in an isolation pen together with one sentinel pig. Approximately every 2 months thereafter one group of animals was euthanized and tissue samples taken for virological and serological analysis. Infectious virus was not isolated from any samples; antibodies to PorPV-LPMV were detected in convalescent pigs by virus neutralisation test and blocking ELISA but not in sentinel pigs. PorPV-LPMV mRNA of the nucleoprotein (NP) and phosphoprotein (P) genes was detected by a nested polymerase chain reaction (nPCR) in samples of trigeminal and optic nerves, cervical spinal cord, tonsils, salivary gland, lung and pancreas from convalescent pigs. mRNA was also detected in the midbrain, corpus callosum, or olfactory bulb in four out of five pigs by nRT-PCR, this result was confirmed by the sequencing of a 260bp PCR product of P gene region. The highest average viral copies/μg of total RNA occurred in the olfactory bulb and pancreas tissues of convalescent pigs and midbrain, tonsil and pancreas of sentinel pigs housed with the convalescent pigs. Satellitosis and gliosis of the midbrain, olfactory bulb, corpus callosum, medulla oblongata or choroid plexus were microscopically observed in four convalescent pigs. The control pig remained negative in all tests. The results indicate that PorPV-LPMV mRNA persists and induces a durable humoral immune response in pigs that have recovered from a natural infection. After a possible reactivation of the virus, it was transmitted to sentinel pigs in contact with the convalescent pigs.

  11. Comparación de resultados del método de clasificación de órbitas por análisis de frecuencias con el método de exponentes de Lyapunov

    NASA Astrophysics Data System (ADS)

    Carpintero, D. D.; Muzzio, J. C.; Wachlin, F. C.

    Hemos realizado extensas comparaciones del método de análisis de frecuencias con el de exponentes de Lyapunov. El primero resulta claramente superior por las siguientes razones: 1) permite distinguir distintos tipos de órbitas y no sólo si son regulares o caóticas 2) es mucho más veloz requiriendo mucho menos tiempo de cómputo. La concordancia de resultados es, en general, buena y se discuten algunas discrepancias.

  12. HRM confirmation of Neisseria gonorrhoeae in clinical specimens by G→A (position 857) mutation detection in the 16S rRNA gene before sequencing and after porA confirmation.

    PubMed

    Gurtler, Volker; Mayall, Barrie C; Wang, Jenny

    2012-05-01

    A total of 2273 specimens submitted to the Austin Hospital Pathology Service for Neisseria gonorrhoeae screening between September 1, 2009 and May 11, 2011 were used in this study. Specimens were simultaneously screened and confirmed with a previously published real time PCR assay for the opa gene (extra primers were included to increase sensitivity) and the porA gene respectively. The opa gene screen and initial porA gene confirmation yielded an N. gonorrhoeae positivity rate of 0.88% (20/2273) and 0.49% (11/2191) for specimens and patients respectively. A 16S rDNA High Resolution Melt confirmatory PCR was developed subsequently; this reduced the N. gonorrhoeae positivity rate to 0.35% (8/2273) and 0.27% (6/2191) for specimens and patients respectively (not altered by 16S sequencing). The higher rate of secondary confirmation (16S HRM) in patients compared with samples was due to the detection of species other than N. gonorrhoeae detected by the initial screening and confirmation test. This underlines the importance of performing the secondary confirmatory test that has been developed in this study.

  13. La inserción en el mercado laboral de los inmigrantes latinos en España y en los Estados Unidos: Diferencias por país de origen y estatus legal

    PubMed Central

    Connor, Phillip; Massey, Douglas

    2013-01-01

    Resumen Este artículo compara los resultados económicos entre los inmigrantes latinoamericanos en España y Estados Unidos. Detectamos un efecto de selección por el que la mayoría de los inmigrantes latinoamericanos en España proceden de Sudamérica de un entorno de clases medias, mientras la mayoría de los inmigrantes que van a los Estados Unidos son centroamericanos de clase baja. Este efecto de selección explica las diferencias transnacionales en la probabilidad de empleo, logro ocupacional y salarios obtenidos. A pesar de las diferencias en los orígenes y las características de los latinoamericanos en ambos países, los factores demográficos, humanos y de capital social parecen operar de forma similar en ambos países; y cuando los modelos se estiman separadamente por estatus legal, descubrimos que los efectos se acentúan más entre los inmigrantes irregulares cuando se los compara con los regulares, especialmente en Estados Unidos. PMID:24532857

  14. Aquisição fonológica do português brasileiro por crianças ouvintes bilíngues bimodais e surdas usuárias de implante coclear

    PubMed Central

    Cruz, Carina Rebello; Finger, Ingrid

    2014-01-01

    Resumo O presente estudo investiga a aquisição fonológica do Português Brasileiro (PB) por 24 crianças ouvintes bilíngues bimodais, com acesso irrestrito à Língua Brasileira de Sinais (Libras), e por 6 crianças surdas que utilizam implante coclear (IC), com acesso restrito ou irrestrito à Libras. Para a avaliação do sistema fonológico das crianças em PB, foi utilizada a Parte A, Prova de Nomeação, do ABFW – Teste de Linguagem Infantil (ANDRADE et al. 2004). Os resultados revelaram que as crianças ouvintes bilíngues bimodais e a criança surda usuária de IC com acesso irrestrito à Libras apresentaram processo de aquisição fonológica esperada (normal) para a sua faixa etária. Considera-se que a aquisição precoce e o acesso irrestrito à Libras podem ter sido determinantes para o desempenho dessas crianças no teste oral utilizado. PMID:25506105

  15. The Understanding of Astronomy Concepts by Students from Basic Education of a Public School. (Spanish Title: El Entendimiento de Conceptos de Aastronmía Por Los Alumnos de Educación Básica en Una Escuela Pública.) O Entendimento de Conceitos de Astronomia Por Alunos da Educação Básica: O Caso de Uma Escola Pública Brasileira

    NASA Astrophysics Data System (ADS)

    Iria Machado, Daniel; dos Santos, Carlos

    2011-07-01

    We present the results obtained in a research on the comprehension of basic astronomical concepts, in which 561 students from fifth grade middle school to third grade high school of a public school of the city of Foz do Iguaçu (Brazil) took part. A test with 20 multiple-choice questions was applied to indentify the most common conceptions expressed by the students. This test was elaborated based on the literature about misconceptions and covered the following topics: the day-night cycle; the time zones; the seasons of the year; the phases of the Moon; the movement of the Moon; the apparent movement of the Sun in the celestial sphere; the eclipses; the dimensions and distances in the Universe; the brightness of the stars and its observation from Earth. Though a small progress was verified in the proportion of scientifically acceptable answers when comparing the eighth grade of middle school to the fifth, and the third grade of high school to the first, there was an overall predominance of alternative conceptions regarding most of the explored subjects, which persisted up to the last year of secondary school. The comparison to data found in this research made in other socio-cultural contexts revealed, in many aspects, similar notions and difficulties revealed by the students. Se presentan los resultados de una investigación sobre la comprensión de conceptos astronómicos básicos, en la cual participaron 561 estudiantes que cursaban entre el quinto grado de la enseñanza primaria y el tercer año de la enseñanza secundaria de una escuela pública de la ciudad de Foz do Iguaçu (Brasil). Se utilizó un test de 20 preguntas de opción múltiple para identificar las concepciones más comunes expresadas por los estudiantes. Este instrumento de recolección de datos se desarrolló en base a la literatura sobre las concepciones alternativas y trató los siguientes temas: el ciclo día-noche, los husos horarios, las estaciones del año, las fases de la Luna, el

  16. The Understanding of Astronomy Concepts by Students from Basic Education of a Public School. (Spanish Title: El Entendimiento de Conceptos de Aastronmía Por Los Alumnos de Educación Básica en Una Escuela Pública.) O Entendimento de Conceitos de Astronomia Por Alunos da Educação Básica: O Caso de Uma Escola Pública Brasileira

    NASA Astrophysics Data System (ADS)

    Iria Machado, Daniel; dos Santos, Carlos

    2011-07-01

    We present the results obtained in a research on the comprehension of basic astronomical concepts, in which 561 students from fifth grade middle school to third grade high school of a public school of the city of Foz do Iguaçu (Brazil) took part. A test with 20 multiple-choice questions was applied to indentify the most common conceptions expressed by the students. This test was elaborated based on the literature about misconceptions and covered the following topics: the day-night cycle; the time zones; the seasons of the year; the phases of the Moon; the movement of the Moon; the apparent movement of the Sun in the celestial sphere; the eclipses; the dimensions and distances in the Universe; the brightness of the stars and its observation from Earth. Though a small progress was verified in the proportion of scientifically acceptable answers when comparing the eighth grade of middle school to the fifth, and the third grade of high school to the first, there was an overall predominance of alternative conceptions regarding most of the explored subjects, which persisted up to the last year of secondary school. The comparison to data found in this research made in other socio-cultural contexts revealed, in many aspects, similar notions and difficulties revealed by the students. Se presentan los resultados de una investigación sobre la comprensión de conceptos astronómicos básicos, en la cual participaron 561 estudiantes que cursaban entre el quinto grado de la enseñanza primaria y el tercer año de la enseñanza secundaria de una escuela pública de la ciudad de Foz do Iguaçu (Brasil). Se utilizó un test de 20 preguntas de opción múltiple para identificar las concepciones más comunes expresadas por los estudiantes. Este instrumento de recolección de datos se desarrolló en base a la literatura sobre las concepciones alternativas y trató los siguientes temas: el ciclo día-noche, los husos horarios, las estaciones del año, las fases de la Luna, el

  17. One-step purification and porin transport activity of the major outer membrane proteins P2 from Haemophilus influenzae, FomA from Fusobacterium nucleatum and PorB from Neisseria meningitidis.

    PubMed

    Kattner, Christof; Pfennig, Sabrina; Massari, Paola; Tanabe, Mikio

    2015-03-01

    Bacterial porins are major outer membrane proteins that function as essential solute transporters between the bacteria and the extracellular environment. Structural features of porins are also recognized by eukaryotic cell receptors involved in innate and adaptive immunity. To better investigate the function of porins, proper refolding is necessary following purification from inclusion bodies [1, 2]. Using a single-step size exclusion chromatographic method, we have purified three major porins from pathogenic bacteria, the OmpP2 (P2) from Haemophilus influenzae, FomA from Fusobacterium nucleatum and PorB from Neisseria meningitidis, at high yield and report their unique solute transport activity with size exclusion limit. Furthermore, we have optimized their purification method and achieved improvement of their thermostability for facilitating functional and structural analyses.

  18. Characterization of fHbp, nhba (gna2132), nadA, porA, sequence type (ST), and genomic presence of IS1301 in group B meningococcal ST269 clonal complex isolates from England and Wales.

    PubMed

    Lucidarme, Jay; Comanducci, Maurizio; Findlow, Jamie; Gray, Stephen J; Kaczmarski, Edward B; Guiver, Malcolm; Kugelberg, Elisabeth; Vallely, Pamela J; Oster, Philipp; Pizza, Mariagrazia; Bambini, Stefania; Muzzi, Alessandro; Tang, Christoph M; Borrow, Ray

    2009-11-01

    Highly effective glycoconjugate vaccines exist against four of the five major pathogenic groups of meningococci: A, C, W-135, and Y. An equivalent vaccine against group B meningococci (menB) has remained elusive due to the poorly immunogenic capsular polysaccharide. A promising alternative, the investigational recombinant menB (rMenB)- outer membrane vesicle (OMV) vaccine, contains fHBP, NHBA (previously GNA2132), NadA, and outer membrane vesicles (OMVs) from the New Zealand MeNZB vaccine. MenB currently accounts for 90% of meningococcal disease in England and Wales, where the multilocus sequence type (ST) 269 (ST269) clonal complex (cc269) has recently expanded to account for a third of menB cases. To assess the potential cc269 coverage of the rMenB-OMV vaccine, English and Welsh cc269 isolates from the past decade were genetically characterized with respect to fHBP, NHBA, and NadA. All of the isolates harbored fHbp and nhba alleles, while 98% of the cc269 isolates were devoid of nadA. Subvariant profiling of fHbp, nhba, and porA against STs revealed the presence of two broadly distinct and well-defined clusters of isolates, centered around ST269 and ST275, respectively. An additional molecular marker, insertion sequence IS1301, was found to be present in 100% and <2% of isolates of the respective clusters. On the basis of the genetic data, the potential rMenB-OMV coverage of cc269 in England and Wales is high (up to 100%) within both clusters. Expression studies and serum bactericidal antibody assays will serve to enhance predictions of coverage and will augment ongoing studies regarding the significance of IS1301 within the ST269 cluster.

  19. Eficacia de la detección sistemática de la gripe en las fronteras en los viajeros que llegan por vía aérea*

    PubMed Central

    Priest, Patricia C.; Jennings, Lance C.; Duncan, Alasdair R.; Brunton, Cheryl R.; Baker, Michael G.

    2015-01-01

    Objetivos. Se midieron los síntomas y la prevalencia de la gripe (también llamada influenza), así como la eficacia del mecanismo de detección sistemática basado en los síntomas y la temperatura para diagnosticar la gripe en viajeros internacionales que llegaban por vía aérea. Métodos. El presente estudio transversal recopiló datos de viajeros que llegaron al aeropuerto internacional de Christchurch (Nueva Zelandia) en el invierno del 2008 mediante un cuestionario de salud, medición de la temperatura y toma de muestras de las vías respiratorias. Resultados. De los viajeros, 15 976 (68%) entregaron los formularios completos. De ellos, 17% notificaron al menos un síntoma de gripe; los síntomas más comunes fueron rinorrea o congestión nasal (10%) y tos (8%). Se tomaron muestras de las vías respiratorias de 3 769 viajeros. La prevalencia estimada de la gripe fue de 1,1% (4% en las personas sintomáticas, 0,2% en las asintomáticas). La sensibilidad de los criterios de detección varió de 84% para “cualquier síntoma” a 3% para la fiebre de 37,8 °C o mayor. El valor predictivo positivo fue bajo para todos los criterios. Conclusiones. El método de detección sistemática en las fronteras mediante la autonotificación de síntomas y la toma de la temperatura presenta limitaciones para impedir que una gripe pandémica entre en un país. Basarse en criterios como “cualquier síntoma” o la tos haría que se investigara a varias personas no infectadas, mientras que algunas personas infectadas pasarían inadvertidas. Si se usaran criterios más específicos como la fiebre, la mayoría de las personas infectadas entrarían en el país a pesar del mecanismo de detección.

  20. Neisseria gonorrhoeae antimicrobial susceptibility in Barcelona: penA, ponA, mtrR, and porB mutations and NG-MAST sequence types associated with decreased susceptibility to cephalosporins.

    PubMed

    Serra-Pladevall, J; Barberá, M J; Rodriguez, S; Bartolomé-Comas, R; Roig, G; Juvé, R; Andreu, A

    2016-09-01

    The aims of this study were to determine the antimicrobial susceptibility of Neisseria gonorrhoeae (NG) in our area, to analyze the molecular mechanisms involved in cephalosporins resistance, and to undertake molecular typing of our NG strains. Antimicrobial susceptibility was determined using the Etest. The genes penA, mtrR, penB, and ponA were studied. Molecular typing was performed by N. gonorrhoeae multiantigen sequence typing. Of 329 strains analyzed in 2013, none showed high-level cephalosporin resistance, but 8.2 % had resistance to cefixime [minimum inhibitory concentration (MIC) > 0.125 μg/mL] and 0.6 % to ceftriaxone (MIC > 0.125 μg/mL). Azithromycin resistance was documented in 4.3 % and ciprofloxacin resistance in 49.2 %. Among 48 strains with an MIC ≥ 0.125 μg/mL to cefixime, 58.3 % showed the penA mosaic pattern XXXIV, 98 % a Leu → Pro substitution at position 421 of the ponA gene, 100 % amino acid changes at positions 101 and 102 of the PorB1b porin, and 87.5 % of strains an adenine deletion in the promoter region of the MtrC-D-E efflux pump. A significant difference between strains with and without decreased cephalosporin susceptibility (MIC ≥ 0.125 μg/mL) was observed for these four genes. Of the 48 strains with an MIC ≥ 0.125 μg/mL to cefixime, 43.8 % belonged to the genogroup G1407 and 27.1 % belonged to the genogroup G2400. A significant association of G1407 with decreased susceptibility (MIC ≥ 0.125 μg/mL) and G2992 with susceptibility was found, and also between G1407 and mosaic pattern XXXIV and between G2400 and A501T substitution in penA. The NG resistance rate in our area is higher than the median of Europe. We have detected the emergence of G2400, which may be a source of antimicrobial resistance. PMID:27255221

  1. Construction and Functional Activities of Chimeric Mouse-Human Immunoglobulin G and Immunoglobulin M Antibodies against the Neisseria meningitidis PorA P1.7 and P1.16 Epitopes

    PubMed Central

    Michaelsen, Terje E.; Ihle, Øistein; Beckstrøm, Karen Johanne; Herstad, Tove K.; Kolberg, Jan; Høiby, E. Arne; Aase, Audun

    2003-01-01

    We studied the in vitro protective activities of human immunoglobulin G1 (IgG1), IgG3, and IgM antibodies against group B meningococci by constructing sets of chimeric mouse-human antibodies (chIgG1, chIgG3, and chIgM, respectively) with identical binding regions against the P1.7 and P1.16 epitopes on PorA. This was done by cloning the V genes of three mouse hybridoma antibodies and subsequently transfecting vectors containing the homologous heavy- and light-chain genes into NSO cells. Cell clones secreting intact human chIgG1, chIgG3, or chIgM antibodies originating from three parent mouse antibodies were isolated. The functional affinities appeared to be similar for all human isotypes and surprisingly also for the pentameric chIgM antibody. chIgG1 exhibited greater serum bactericidal activity (SBA) than chIgG3, while chIgG3 was more efficient in inducing a respiratory burst (RB) associated with opsonophagocytosis than chIgG1 was. On the other hand, chIgM exhibited SBA similar to that of chIgG1, but it exhibited much higher RB activity than chIgG3 and chIgG1 exhibited. The antibodies against the P1.16 epitope were more efficient in terms of SBA than the antibodies against the P1.7 epitope were; thus, 10- to 40-fold-lower concentrations of antibodies against P1.16 than of antibodies against P1.7 were needed to induce SBA. On the other hand, antibodies against these epitopes were equally effective in inducing RB. Our results revealed differences in the functional activities of human chIgG1, chIgG3, and chIgM antibodies against meningococci, which might influence their protective effects against meningococcal disease. PMID:14500492

  2. Characterization of fHbp, nhba (gna2132), nadA, porA, and sequence type in group B meningococcal case isolates collected in England and Wales during January 2008 and potential coverage of an investigational group B meningococcal vaccine.

    PubMed

    Lucidarme, Jay; Comanducci, Maurizio; Findlow, Jamie; Gray, Stephen J; Kaczmarski, Edward B; Guiver, Malcolm; Vallely, Pamela J; Oster, Philipp; Pizza, Mariagrazia; Bambini, Stefania; Muzzi, Alessandro; Borrow, Ray

    2010-06-01

    Invasive disease caused by meningococcal capsular groups A, C, W-135, and Y is now preventable by means of glycoconjugate vaccines that target their respective polysaccharide capsules. The capsule of group B meningococci (MenB) is poorly immunogenic and may induce autoimmunity. Vaccines based on the major immunodominant surface porin, PorA, are effective against clonal epidemics but, thus far, have a limited scope of coverage against the wider MenB population at large. In an alternative approach, the first-generation, investigational, recombinant MenB (rMenB) plus outer membrane vesicle (OMV) (rMenB-OMV) vaccine contains a number of relatively conserved surface proteins, fHBP, NHBA (previously GNA2132), and NadA, alongside PorA P1.4-containing OMVs from the New Zealand MeNZB vaccine. MenB currently accounts for approximately 90% of cases of meningococcal disease in England and Wales. To assess potential rMenB-OMV vaccine coverage of pathogenic MenB isolates within this region, all English and Welsh MenB case isolates from January 2008 (n = 87) were genetically characterized with respect to fHBP, NHBA, NadA, and PorA. Alleles for fHbp, nhba, and porA were identified in all of the isolates, of which 22% were also found to harbor nadA alleles. On the basis of genotypic data and predicted immunological cross-reactivity, the potential level of rMenB-OMV vaccine coverage in England and Wales ranges from 66% to 100%.

  3. PREDICTION OF DIOXIN/FURAN INCINERATOR EMISSIONS USING LOW-MOLECULAR-WEIGHT VOLATILE PRODUCTS OF INCOMPLETE COMBUSTION

    EPA Science Inventory

    Emissions of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) from incinerators and other stationary combustion sources are of environmental concern because of the toxicity of certain PCDD/PCDF congeners. Measurement of trace levels of PCDDs/PCDFs...

  4. Isomer-specific determination of polychlorinated dibenzo-p-dioxins and dibenzofurans in incinerator-related environmental samples

    SciTech Connect

    Yasuhara, A.; Ito, H.; Morita, M.

    1987-10-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) ranging from tetra- to octachloro congeners in ash and fly ash from incinerators, river water, effluent water from incinerators, groundwater, soil, and sediment were determined isomer specifically by high-resolution gas chromatograph-mass spectrometry in order to manifest an environmental situation polluted with those compounds in Japan. The most toxic 2,3,7,8-tetrachlorodibenzo-p-dioxin was detected only in fly ash. In many samples, octachlorodibenzo-p-dioxin had the highest abundance in PCDDs, and heptachlorodibenzofurans had the highest abundance in PCDFs. Gas chromatographic patterns of PCDDs and PCDFs in all samples were compared with each other by use of the pattern similarity method in order to classify the pollution pattern with PCDDs and PCDFs. Gas chromatographic patterns of PCDDs and PCDFs in fly ash, effluent water, and sediment were different from each other.

  5. Human dietary exposure and levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs) and non-dioxin-like polychlorinated biphenyls (NDL-PCBs) in free-range eggs close to a secondary aluminum smelter, Northern Italy.

    PubMed

    Squadrone, S; Brizio, P; Nespoli, R; Stella, C; Abete, M C

    2015-11-01

    PCDD/Fs and PCBs are environmentally persistent substances that have been associated with adverse effects on human health. Contamination of soils, animal feed and pastures leads to their bioaccumulation of in food products of animal origin, which are considered the major source of intake of these contaminants in humans. We analyzed eggs from free-range hens, sampled from small farms, located within a distance of 4.5 km from a secondary aluminum smelter in Northern Italy. The concentrations of PCDD/Fs, DL-PCBs and NDL-PCBs were higher in eggs from locations close to the plant, and strongly exceeded the limits set by EU Regulation 1259/2011 (2.5 pg WHO TEQ fat g(-1) for PCDD/Fs, 5.0 pg WHO TEQ g(-1) for PCDD/Fs and DL-PCBs L, 40 ng g(-1) for NDL-PCBs). Without the prompt and immediately applied control strategies, the consumption of contaminated eggs may have posed [corrected] a risk for human health, especially for children (≤9 years) and infants (≤3 years), due to the 2-fold excess of the current exposure limits.

  6. New halide-centered discrete Ag(I)(8) cubic clusters containing diselenophosphate ligands, [Ag(8)(X)[Se(2)P(OR)(2)](6)](PF(6)) (X = Cl, Br; R = Et, Pr, (i)Pr): syntheses, structures, and DFT calculations.

    PubMed

    Liu, C W; Haia, Hsien-Chung; Hung, Chiu-Mine; Santra, Bidyut Kumar; Liaw, Ben-Jie; Lin, Zhenyang; Wang, Ju-Chun

    2004-07-12

    Six clusters Ag(8)(micro(8)-X)[Se(2)P(OR)(2)](6)(PF(6)) (R = Et, X = Cl, 1a, X = Br, 1b; R = Pr, X = Cl, 2a, X = Br, 2b; R = (i)Pr, X = Cl, 3a, X = Br, 3b) were isolated from the reaction of [Ag(CH(3)CN)(4)](PF(6)), NH(4)[Se(2)P(OR)(2)], and Bu(4)NX in a molar ratio of 4:3:1 in CH(2)X(2). Positive FAB mass spectra show m/z peaks at 2573.2 for 1a, 2617.3 for 1b, 2740.9 for 2a, 2786.9 for 2b, 2742.3 for 3a, and 2787.0 for 3b due to respective molecular cation, (M - PF(6))(+). (31)P NMR spectra of 1a-3b display a singlet at delta 82.3, 81.5, 82.9, 81.7, 76.3, and 75.8 ppm with a set of satellites (J(PSe) = 661, 664, 652, 652, 656, and 656 Hz, respectively). The X-ray structure (1a-2b) consists of a discrete cationic cluster in which eight silver ions are linked by six diselenophosphate ligands and a central micro(8)-Cl or micro(8)-Br ion with a noncoordinating PF(6)(-) anion. The shape of the molecule is a halide-centered distorted Ag(8) cubic cluster. The dsep ligand exhibits a tetrametallic tetraconnective (micro(2), micro(2)) coordination pattern, and each caps on a square face of the cube. Each silver atom of the cube is coordinated by three selenium atoms and the central chloride or bromide ion. Additionally, molecular orbital calculations at the B3LYP level of the density functional theory have been carried out to study the Ag-micro(8)-X (X = Cl, Br) interactions for cluster cations [Ag(8)(micro(8)-X)[Se(2)P(OR)(2)](6)](+). Calculations show very weak bonding interactions exist between micro(8)-X and Ag atoms of the cube. PMID:15236560

  7. Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans from chemical manufacturers and waste disposal facilities.

    PubMed

    Muto, H; Saito, K; Shinada, M; Takizawa, Y

    1991-04-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in various source and environmental samples obtained from eight chemical manufacturers producing agricultural chemicals, synthetic dye, or resin and eight chemical waste disposal facilities. The concentrations of PCDDs and PCDFs ranged from 3.0 to 3504 ng/g for PCDDs and from 1.2 to 1668 ng/g for PCDFs in fly ash. Their concentrations in emission were in the ranges of 21.8 to 3205 ng/m3 for PCDDs and not detected to 4344 ng/m3 for PCDFs. PCDD and PCDF concentrations were higher in fly and bottom ashes and in emissions from two manufacturers that incinerate waste plastics than in those from other manufacturers. For emission and liquid samples from the manufacturers. For emission and liquid samples from the manufacturers of agricultural chemicals, significantly high concentrations of tetra-CDDs were detected. Furthermore, the high concentrations of PCDFs, especially hepta- and octa-CDF congeners, existed in emissions from waste incinerators that manufacture rubber. Among manufacturers and disposal facilities, the total emission equivalent (2.94 ng/m3) of PCDDs and PCDFs was highest for a certain manufacturer of agricultural chemicals, showing that more 2,3,7,8-chlorine-substituted PCDDs and PCDFs were present in their emissions.

  8. Polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in rice straw smoke and their origins in Japan.

    PubMed

    Minomo, Kotaro; Ohtsuka, Nobutoshi; Nojiri, Kiyoshi; Hosono, Shigeo; Kawamura, Kiyoshi

    2011-08-01

    Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) contained in the smoke generated from rice straw burning in post-harvest paddy fields in Japan were analyzed to determine their congener profiles. Both the apportionment of toxic equivalent (TEQ) by using indicative congeners and the comparison of the homolog profiles showed that the PCDDs/PCDFs/DL-PCBs present in the rice-straw smoke were greatly influenced by those present as impurities in pentachlorophenol (PCP) and chlornitrofen (CNP, 4-nitrophenyl-2,4,6-trichlorophenyl ether) formulations that had been widely used as herbicides in paddy fields in Japan. Further, in order to investigate the effects of paddy-field soil on the PCDDs/PCDFs/DL-PCBs present in rice-straw smoke, PCDD/PCDF/DL-PCB homolog profiles of rice straw, rice-straw smoke and paddy-field soil were compared. Rice-straw smoke was generated by burning rice straw on a stainless-steel tray in a laboratory. The results suggested that the herbicides-originated PCDDs/PCDFs/DL-PCBs and the atmospheric PCDDs/PCDFs/DL-PCBs contributed predominantly to the presence of PCDDs/PCDFs/DL-PCBs in the rice-straw smoke while the contribution of PCDDs/PCDFs/DL-PCBs formed during rice straw burning was relatively minimal. The major sources of the PCDDs/PCDFs/DL-PCBs found in the rice-straw smoke were attributed primarily to the paddy-field soil adhered to the rice straw surface and secondarily to the air taken by the rice straw. The principal component analysis supported these conclusions. It is concluded that rice straw burning at paddy fields acts as a driving force in the transfer of PCDDs/PCDFs/DL-PCBs from paddy-field soil to the atmosphere.

  9. La busqueda textual por computadora (Textual Search by Computer)

    ERIC Educational Resources Information Center

    Davison, Ned J.

    1977-01-01

    Describes the use of the computer program EDIT for textual searches to locate a certain programmed word or word root. In the examples explained here, the vocabulary search is performed on poetry and allows examination of the metaphorical and conceptual poetic atmosphere achieved through word use. (Text is in Spanish.) (CHK)

  10. AN ALTERNATIVE METHOD FOR ESTABLISHING TEFS FOR DIOXIN-LIKE COMPOUNDS. PART 1. EVALUATION OF DECISION ANALYSIS METHODS FOR USE IN WEIGHTING RELATIVE POTENCY DATA

    EPA Science Inventory

    A number of investigators have recently examined the utility of applying probabilistic techniques in the derivation of toxic equivalency factors (TEFs) for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (...

  11. IMMUNOCHEMICAL DETERMINATION OF DIOXINS IN SEDIMENT SAMPLES

    EPA Science Inventory

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are considered highly toxic contaminants with the environmental monitoring of these compounds being of great importance. Immunoassay procedures such as the enzyme-linked immunosorbent assay (ELIS...

  12. IMMUNOCHEMICAL DETERMINATION OF DIOXINS IN SEDIMENT AND SERUM SAMPLES

    EPA Science Inventory

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are considered highly toxic contaminants and the environmental and biological monitoring of these compounds is of great concern. Immunoassays may be used as screening methods to satisfy the gro...

  13. A PERFORMANCE HISTORY OF THE BASE CATALYZED DECOMPOSITION (BCD) PROCESS

    EPA Science Inventory

    Remediation of halogenated organic compounds--such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs)--poses a challenge because these compounds are resistant to microbial attack and to degradation by many com...

  14. Results of the combustion and emissions research project at the Vicon Incinerator Facility in Pittsfield, Massachusetts: Volume 3, Appendices H-K: Final report

    SciTech Connect

    Not Available

    1987-06-01

    Atmospheric emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) can be generated as a result of combustion of municipal solid waste (MSW). However, knowledge is limited about the incinerator design and operating conditions that cause these compounds to form and that can be adjusted to minimize or eliminate their discharge. This study focused on identifying the relationships between incinerator operating conditions, waste characteristics, combustion variables, and levels of PCDDs and PCDFs and selected other semivolatile organic compounds measured in the combustion gases. The study was designed primarily to evaluate the effect of the following parameters on levels of PCDDs/PCDFs in the combustion gases:Incinerator operating conditions; PVC content of the waste; Moisture content of the waste; and Combustion gas variables. Further, the study investigated the relationship between levels of PCDDs/PCDFs and other semivolatile organic compounds measured in the combustion gases.

  15. Results of the combustion and emissions research project at the Vicon Incinerator Facility in Pittsfield, Massachusetts: Volume 2, Appendices A-G: Final report

    SciTech Connect

    Not Available

    1987-06-01

    Atmospheric emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) can be generated as a result of combustion of municipal solid waste (MSW). However, knowledge is limited about the incinerator design and operating conditions that cause these compounds to form and that can be adjusted to minimize or eliminate their discharge. This study focused on identifying the relationships between incinerator operating conditions, waste characteristics, combustion variables, and levels of PCDDs and PCDFs and selected other semivolatile organic compounds measured in the combustion gases. The study was designed primarily to evaluate the effect of the following parameters on levels of PCDDs/PCDFs in the combustion gases: Incinerator operating conditions; PVC content of the waste; Moisture content of the waste; and Combustion gas variables. Further, the study investigated the relationship between levels of PCDDs/PCDFs and other semivolatile organic compounds measured in the combustion gases.

  16. Results of the combustion and emissions research project at the Vicon Incinerator Facility in Pittsfield, Massachusetts: Volume 4, Appendices L-O: Final report

    SciTech Connect

    Not Available

    1987-06-01

    Atomspheric emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) can be generated as a result of combustion of municipal solid waste (MSW). However, knowledge is limited about the incinerator design and operating conditions that cause these compounds to form and that can be adjusted to minimize or eliminate their discharge. This study focused on identifying the relationships between incinerator operating conditions, waste characteristics, combustion variables, and levels of PCDDs and PCDFs and selected other semivolatile organic compounds measured in the combustion gases. The study was designed primarily to evaluate the effect of the following parameters on levels of PCDDs/PCDFs in the combustion gases: Incinerator operating conditions; PVC content of the waste; Moisture content of the waste; and Combustion gas variables. Further, the study investigated the relationship between levels of PCDDs/PCDFs and other semivolatile organic compounds measured in the combustion gases.

  17. EMISSIONS OF METALS, CHROMIUM AND NICKEL SPECIES, AND ORGANICS FROM MUNICIPAL WASTEWATER SLUDGE INCINERATORS

    EPA Science Inventory

    In order to provide data to support regulations on municipal wastewater sludge incineration, emissions of metals, hexavalent chromium, nickel subsulfide, polychlorinated dibenzo-dioxins and furans (PCDD/PCDFs), semivolatile and volatile organic compounds, carbon monoxide (CO)...

  18. ROLE OF SULFUR IN REDUCING PCDD AND PCDF FORMATION

    EPA Science Inventory

    Past research has suggested that the presence of sulfur (S) in municipal waste combustors (MWCs) can decrease downstream formation of chlorinated organic compounds, particularly polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Thus, co-firing a...

  19. PCDD AND PCDF EMISSIONS FROM SIMULATED SUGARCANE FIELD BURNING

    EPA Science Inventory

    The emissions from simulated sugarcane field burns were sampled and analyzed for polychlorinated dibenzodioxins and dibenzofurans (PCDDs and PCDFs). Sugarcane leaves from Hawaii and Florida were burned in a manner simulating the natural physical dimensions and biomass density fou...

  20. AN ALTERNATIVE METHOD FOR ESTABLISHING TEFS FOR DIXON-LIKE COMPOUNDS. PART 2. DEVELOPMENT OF AN APPROACH TO QUANTITATIVELY WEIGHT THE UNDERLYING POTENCY DATA

    EPA Science Inventory

    The current approach for evaluating potential health risks associated with exposure to mixtures of polychlorinated dibenzo-p-dixoins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs) [hereafter referred to as "dioxin-like compoun...

  1. AN ALTERNATIVE METHOD FOR ESTABLISHING TEFS FOR DIOXIN-LIKE COMPOUNDS. PART 3. DEVEOPMENT OF WEIGHTED DISTRIBUTIONS OF REPS FOR PCB 126 AND 2,3,4,7,8-PECDF

    EPA Science Inventory

    Currently, regulatory agencies utilize the toxic equivalency factor (TEF) approach to evaluate potential health risks associated with exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs). Th...

  2. Degradation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans by the white rot fungus Phanerochaete sordida YK-624.

    PubMed Central

    Takada, S; Nakamura, M; Matsueda, T; Kondo, R; Sakai, K

    1996-01-01

    A method for the degradation of dioxins by white rot fungi was developed. Degradation of a mixture of 10 kinds of tetra- to octachlorodibenzo-p-dioxins (polychlorinated dibenzo-p-dioxins [PCDDs]) and tetra- to octachlorodibenzofurans (polychlorinated dibenzofurans [PCDFs]), which were chlorinated at 2-, 3-, 7-, and 8-positions of the molecules, by the white rot fungus Phanerochaete sordida YK-624 was studied in a stationary low-nitrogen medium. The percent degradation values of PCDDs and PCDFs were approximately 40 (tetra-chloro-) to 76% (hexachloro-) and 45 (tetrachloro-) to 70% (hexachloro-), respectively. Metabolites of 2,3,7,8-tetra- and octaCDD formed by P. sordida YK-624 included 4,5-dichlorocatechol and tetrachlorocatechol, respectively. These results suggest that white rot fungus is able to substantially degrade both PCDDs and PCDFs. This is the first report of the degradation of highly chlorinated PCDDs and PCDFs by a microorganism. PMID:8953705

  3. Formation of polychlorinated dibenzofurans and dioxins during combustion, electrical equipment fires and PCB incineration.

    PubMed Central

    Hutzinger, O; Choudhry, G G; Chittim, B G; Johnston, L E

    1985-01-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are likely formed by thermal synthesis of a variety of primary precursors. Highest levels of these compounds are expected, however, when the starting material requires only one or two reaction steps for their formation, as is the case with chlorophenols, chlorobenzenes and polychlorinated biphenyls (PCBs). Laboratory pyrolyses have indeed shown that PCBs give significant yields of PCDFs, and chlorobenzenes give both PCDFs and PCDDs. In addition, a variety of other chloroaromatic compounds are formed. From these experiments and from accidents involving PCB fires, it is known that PCDFs are the most important toxic compounds associated with PCBs. Most commercial PCBs contain PCDFs in the low ppm range. PCDF concentration does not increase during normal operation in electrical equipment. Accidents (fires and explosions) involving PCBs can give PCDF levels in soot of up to 1000 ppm and higher. Effective thermal destruction of PCB is possible in modern incineration units, provided high temperatures, excess air and sufficient residence times are used. Exact figures for minimum temperature and residence time cannot be given, since feedstock and incinerator construction greatly influence destruction efficiency. Effluents from EPA-licensed incinerators used for PCB destruction contain only very low levels of PCDDs and PCDFs. PMID:3928357

  4. Human health risks of dioxins for populations living near modern municipal solid waste incinerators.

    PubMed

    Domingo, Jose L

    2002-01-01

    Although incineration is an effective way of treating municipal solid waste (MSW), in many countries the potential health risks associated with stack emissions, particularly those of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), have become a cause of great controversy and concern. Given the interest and importance of this controversy, in the present paper a series of experimental data corresponding to a number of surveys made in the vicinity of three MSW incinerators (MSWIs) of Catalonia (Spain) are reviewed. In recent months, an adaptation to the EU legislation on pollutant emissions from the stack was carried out in these facilities. We assessed whether the pronounced reductions in the atmospheric PCDD/PCDFs emissions parallel the concurrent decreases in environmental matrices collected in the vicinity of the MSWIs. In comparison with other PCDD/PCDFs emission sources in the areas under direct influence of the MSWIs, the health risks from current emissions of PCDD/PCDFs by these incinerators would be of low significance for populations living in the neighborhood. For such populations, the daily intake of PCDD/PCDFs from direct and indirect (diet) exposure are currently within the rank recommended by the WHO as the maximum daily exposure to PCDD/PCDFs for non-carcinogenic adverse effects.

  5. Síndrome del Outlet Torácico: ¿Una Patología Siempre Quirúrgica? Análisis de una Serie de 31 Cirugías Realizadas por Vía Supraclavicular Serie clínica

    PubMed Central

    Socolovsky, Mariano; Di Masi, Gilda; Binaghi, Daniela; Campero, Álvaro; Páez, Miguel Domínguez; Dubrovsky, Alberto

    2014-01-01

    Introducción: El síndrome de outlet torácico es una compresión del plexo braquial que suscita polémica. Se clasifica en Outlet Torácico Verdadero o neurogénico (OTV) y Outlet Torácico Disputado o no neurogénico (OTD). El primero presenta síntomas motores en la mano, mientras que el segundo sólo síntomas sensitivos en el miembro superior. El objetivo de este trabajo es analizar los resultados obtenidos en una serie de 31 cirugías. Métodos: Se analizaron las cirugías de nervios efectuadas entre 2003-2012, tomando los diagnósticos de outlet torácico cuyo período de seguimiento post-operatorio mínimo fuera de 6 meses. Se buscaron los siguientes datos: edad, sexo, presencia de síntomas sensitivos y/o motores, clasificación, resultado de los estudios neurofisiológicos y de imágenes, resultado de la cirugía, complicaciones post-operatorias y recidivas. Resultados: Se incluyeron 31 cirugías realizadas en 30 pacientes, 9 OTV (8 mujeres) de 24.3 años, y 21 con OTD (18 mujeres) de 37.4 años de edad en promedio. Un 90% presentaron alteraciones neurofisiológicas preoperatorias, y 66,6% imagenológicas. En el intraoperatorio, el 100% de los OTV presentó una alteración anatómica relacionada con la sintomatología, hecho observado sólo en el 36.7% de los OTD operados. El 87,5% de los OTV mejoraron sensitivamente, mientras que 77,7% mejoraron la atrofia. Por el contrario, 45.4% de los OTD mejoraron permanentemente, 36.3% no tuvieron cambios, 13.6% mejoraron transitoriamente y 4.5% (un caso) empeoró. Las complicaciones post-operatorias fueron más frecuentes aunque transitorias en el grupo de OTV (3 casos sobre 9 operados, 33.3%) que en los OTD (3 casos sobre 22, un 13.6%). Conclusión: El OTV suele mayormente mejorar luego de la cirugía, igual que el OTD aunque en una proporción mucho menor. Estos hallazgos coinciden con otros reportes recientes de esta patología. PMID:25165614

  6. A Comparison Between PSRK and GERG-2004 Equation of State for Simulation of Non-Isothermal Compressible Natural Gases Mixed with Hydrogen in Pipelines / Porównanie równań stanu opracowanych według metody PSRK oraz GERG-2004 wykorzystanych do symulacji zachowania ściśliwych mieszanin gazu ziemnego i wodoru w rurociągach, w warunkach przepływów nie-izotermicznych

    NASA Astrophysics Data System (ADS)

    Uilhoorn, Frits E.

    2013-06-01

    In this work, the GERG-2004 equation of state based on a multi-fluid approximation explicit in the reduced Helmholtz energy is compared with the predictive Soave-Redlich-Kwong group contribution method. In the analysis, both equations of state are compared by simulating a non-isothermal transient flow of natural gas and mixed hydrogen-natural gas in pipelines. Besides the flow conditions also linepack-energy and energy consumption of the compressor station are computed. The gas flow is described by a set of partial differential equations resulting from the conservation of mass, momentum and energy. A pipeline section of the Yamal-Europe gas pipeline on Polish territory has been selected for the case study. W artykule dokonano porównania wyników uzyskanych przy wykorzystaniu równania stanu GERG- 2004 opartego na jawnym przybliżeniu wyników dla wielu cieczy w oparciu o zredukowaną energię Helmhotza oraz wyników uzyskanych w oparciu o metodę Soave-Redlich Kwonga. Obydwa równania stanu porównano poprzez przeprowadzenie symulacji stanów przejściowych przepływów gazu ziemnego oraz mieszanin gazu ziemnego i wodoru w rurociągach w warunkach przepływów nie-izotermicznych. Oprócz warunków przepływu, określono energię w napełnionym układzie oraz zużycie energii przez stację kompresora. Przepływ gazu opisano zbiorem równań różniczkowych cząstkowych, wyprowadzonych w oparciu o prawa zachowania masy, pędu i energii. Jako studium przypadku wybrano fragment rurociągu jamalskiego (Yamal- Europa) przebiegającego przez terytorium Polski.

  7. Thermal desorption of PCBs from contaminated soil with copper dichloride.

    PubMed

    Liu, Jie; Qi, Zhifu; Li, Xiaodong; Chen, Tong; Buekens, Alfons; Yan, Jianhua; Ni, Mingjiang

    2015-12-01

    Copper dichloride is an important catalyst both in the dechlorination of chlorinated aromatic compounds and the formation of PCDD/Fs. The effect of copper dichloride on polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) was studied in treated soil and off gas after thermal desorption of PCB-contaminated soil at 300, 400, 500, 600 °C. The presence of copper dichloride clearly enhances thermal desorption by promoting PCBs removal, destruction, and dechlorination. After thermal treatment at 600 °C for 1 h, the removal efficiency and destruction efficiency for PCBs reached 98.1 and 93.9%, respectively. Compared with the positive influence on PCBs, copper dichloride catalyzed large amount of PCDFs formation at 300 °C, with the concentration ratio of 2.35. The effect of CuCl2 on PCDFs formation weakened with the rising temperature since PCDFs destruction became dominant under higher temperature. Different from PCDFs, PCDDs concentration in treated soil and off gas decreased continuously with the increasing temperature. PMID:26233752

  8. Thermal desorption of PCBs from contaminated soil with copper dichloride.

    PubMed

    Liu, Jie; Qi, Zhifu; Li, Xiaodong; Chen, Tong; Buekens, Alfons; Yan, Jianhua; Ni, Mingjiang

    2015-12-01

    Copper dichloride is an important catalyst both in the dechlorination of chlorinated aromatic compounds and the formation of PCDD/Fs. The effect of copper dichloride on polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) was studied in treated soil and off gas after thermal desorption of PCB-contaminated soil at 300, 400, 500, 600 °C. The presence of copper dichloride clearly enhances thermal desorption by promoting PCBs removal, destruction, and dechlorination. After thermal treatment at 600 °C for 1 h, the removal efficiency and destruction efficiency for PCBs reached 98.1 and 93.9%, respectively. Compared with the positive influence on PCBs, copper dichloride catalyzed large amount of PCDFs formation at 300 °C, with the concentration ratio of 2.35. The effect of CuCl2 on PCDFs formation weakened with the rising temperature since PCDFs destruction became dominant under higher temperature. Different from PCDFs, PCDDs concentration in treated soil and off gas decreased continuously with the increasing temperature.

  9. Toxic equivalency factors for tetra- through octachlorinated dibenzofurans in PLHC-1 fish hepatoma cell line

    SciTech Connect

    Tysklind, M.; Rappe, C.; Tillift, D.E.; Eriksson, L.

    1995-12-31

    Planar halogenated hydrocarbons (PHHs) elicit dioxin-like effects in fish at extremely low doses. However, the relative potencies of PHHs in fish differ from mammals in both absolute magnitude and relative rank order. Therefore, the relative potencies of polychlorinated dibenzofurans (PCDFs) were examined in PLHC-1 fish hepatoma cells. The response of PHHs in this cell line correlates with their toxicity to cause early life stage toxicity in fish. Twenty PCDFs were selected by means of a multivariate chemical characterization in combination with a 2{sup 4}-factorial design and separated into a 10 congener training set and 10 congener validation set. Toxic equivalency factors (TEFs) were determined for all 20 PCDF congeners based on ethoxyresorufin-O-deethylase (EROD) induction in the PLHC-1 cells. A quantitative structure-activity relation-ship (QSAR) model was constructed by partial least square modelling (PLS) of the physiochemical descriptor variables for the PCDFs in the training set and their EROD responses in the PLHC-1 cells. A predictive model was developed which accurately assessed the TEFs of the validation set of PCDFs. The model accounted for 87% (R{sup 2}) of the variance in TEFs and a cross-validated variance (Q{sup 2}) of 79%. From this QSAR, TEF values were predicted for all of the tetra through octa-chlorinated PCDFs in fish. Interestingly, there was a high degree of correlation among TEF values calculated in the PLHC-1 cells and the TEF values calculated in H411 E rat hepatoma cells.

  10. Polychlorinated dibenzo- p-dioxins, dibenzofurans, and biphenyls in soils of Moscow

    NASA Astrophysics Data System (ADS)

    Shelepchikov, A. A.; Brodskii, E. S.; Feshin, D. B.; Zhil'Nikov, V. G.; Mir-Kadyrova, E. Ya.; Balashova, S. P.

    2011-03-01

    The contents of polychlorinated dibenzo- p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in the soils of Moscow were estimated. The concentrations of PCDDs and PCDFs mainly vary in the range of 0.27-16.1 ng WHO-TEQ/kg with single points of very high contamination up to 57.3 ng WHO-TEQ/kg; the concentrations of PCBs are in the range of 2.1-50.8 ng/g with sites of high contamination up to 4020 ng/g. The contribution of dioxin-like PCBs to the total dioxin toxic equivalent is very high: from 16 to 85%. The high levels of PCDDs and PCDFs in the soils indicate the strong contamination of the atmospheric air. The main source of these compounds is apparently motor transport.

  11. Dioxin-like compound compositional profiles of furnace bottom ashes from household combustion in Poland and their possible associations with contamination status of agricultural soil and pine needles.

    PubMed

    Wyrzykowska, Barbara; Hanari, Nobuyasu; Orlikowska, Anna; Yamashita, Nobuyoshi; Falandysz, Jerzy

    2009-06-01

    A compositional profile of PCDDs, PCDFs, non- and mono-ortho PCBs, and PCNs of several type furnace bottom ashes obtained after the heating muffle stove for domestic use combustion of hard coal, coke, wood, and solid domestic waste mixture have been examined as possible contributors to environmental diffusion with these compounds in Poland. The uppermost concentration of dioxin-like compounds with 2.0 ng TEQ kg(-1) dry weight found for wood ash was dominated by PCDDs and PCDFs, while for other types of ashes were in the range from 0.052 ng TEQ kg(-1) to 0.67 ng TEQ kg(-1) dry weight. The multivariate statistical analysis displayed some compositional similarity of PCDDs, PCDFs and PCNs between the ashes and environmental pine needle or agricultural soil matrices collected in Poland. PMID:19356784

  12. See the World on the Internet: Tips for Parents of Young Readers--and "Surfers" = Vea el mundo por Internet: Ideas por padres de jovenes lectores y exploradores.

    ERIC Educational Resources Information Center

    Moss, Jeanette

    Regardless of whether a parent has Internet access at home, it is essential that parents learn with their children and be aware of where their travels on the Internet are taking them. Many libraries have Internet workshops for parents or children or both. In the excitement of looking at sites, children may not even realize they are reading. Many…

  13. Verification and validation interim report for portable 1,000 CFM exhauster skids POR-007/Skid E and POR-008/Skid F

    SciTech Connect

    Nelson, O.D.

    1998-07-25

    This Verification and Validation (V/V) interim report summarizes to date the results of the V/V tasks performed in each of the following life cycle phases: concept, requirements, design, implementation, test, installation and checkout, and operation and maintenance. At the end of the installation and checkout phase, the V/V final report will be issued. This interim report contains or references the following for each phase: Description of V/V tasks performed; Summary of task results; Summary of anomalies and resolution; Assessment of system quality; Recommendations.

  14. Gender-related decrease in raven`s progressive matrices scores in children prenatally exposed to polychlorinated biphenyls and related contaminants

    SciTech Connect

    Guo, Y.L.; Lai, T.J.; Chen, S.J.; Hsu, C.C.

    1995-07-01

    Polychlorinated biphenyls (PCBs) and industrial mixtures that have been widely used throughout the world. PCBs have long environmental half lives and bioconcentrate, therefore contaminating soil, water, wild life, and human tissues. Typical human exposures come from environmental contamination of food supply, especially fresh water fish and meat, and occupational exposures. In certain uses, PCBs can partially oxidize and themselves become contaminated by extremely toxic compounds such as polychlorinated dibenzofurans (PCDFs). Two episodes of intoxication with heat-degraded PCBs have occurred, in Japan and Taiwan respectively. In 1979, over 2000 persons in Taiwan were intoxicated by heat-degraded PCBs that had contaminated their cooking oil. Kaneclor 500 (a Japanese PCB mixture) contained in the heating pipe was used as the heat transmitter. Leakage of the pipe introduced PCBs and heat-degraded products such as polychlorinated dibenzofurans (PCDFs) and polychlorinated quaterphenyls (PCQs) into the rice oil. Exposed victims developed chloracne, hyperpigmentation, peripheral neuropathy, and other signs and symptoms which were later called Yu-Cheng ({open_quotes}oil disease{close_quotes}) in Taiwan. These symptoms were caused not only by PCBs but by their heat degraded products, PCDFs. PCBs, PCDFs and PCDDs also can cross the placenta to affect the fetus and cause significant neurodevelopmental toxicity. Raven`s Colored Progressive Matrices (CPM) and Standarized Progressive Matrices (SPM) test spatial rather than verbal capabilities in children. These test are useful for determining whether prenatal exposure to PCBs/PCDFs cause differential effects on boys and girls. This paper reports results of CPM and SPM from age six to nine year in Yu-Cheng children and their matched controls. Cognative deficits up to 9 years of age were detected n children with prenatal exposure to PCBs and PCDFs, and boys were more affected than girls. 26 refs., 1 fig., 2 tabs.

  15. Polychlorinated biphenyls, dibenzofurans and quaterphenyls in toxic rice-bran oil and in the blood and tissues of patients with PCB poisoning (Yu-Cheng) in Taiwan

    SciTech Connect

    Chen, P.H.; Wong, C.K.; Rappe, C.; Nygren, M.

    1985-02-01

    A mass outbreak of poisoning occurred in central Taiwan in 1979 due to the ingestion of rice-bran oil contaminated with polychlorinated biphenyls (PCBs), dibenzofurans (PCDFs) and quaterphenyls (PCQs). The incident was called PCB poisoning or Yu-Cheng in Taiwan. The major PCB and PCDF congeners in the toxic oil and in the blood and tissues of the poisoned patients were characterized by gas chromatography and gas chromatography-mass spectrometry using highly efficient glass capillary columns. The levels of toxic agents in the rice oil samples collected from the factory and school cafeterias and the families of the poisoned patients are in the range of 53 to 99 ppm, 0.18 to 0.40 ppm and 25 to 53 ppm for PCBs, PCDFs, and PCQs, respectively. The blood samples of 165 patients collected 9 to 18 months after the onset of poisoning contained 10 to 720 ppb of PCBs, with a mean value of 38 ppb. The blood samples of 10 patients collected 9 to 27 months after poisoning contained 0.02 to 0.20 ppb of PCDFs. Comparative rates of elimination of some PCB congeners from the blood of patients were studied. Various tissues from a patient who died 2 years after poisoning were analyzed for PCBs, PCDFs and PCQs. The intestinal fat contains the highest level of PCBs, while the liver contains the highest concentration of PCDFs. The major PCDF congeners retained in the tissues were 1,2,3,4,7,8-hexachloro-DF, 2,3,4,7,8-pentachloro-DF and 1,2,4,7,8-pentachloro-DF. The former two congeners, especially 2,3,4,7,8-pentachloro-DF, are very toxic PCDFs; they may play important roles in the etiology of Yu-Cheng.

  16. Characteristics of air pollution by polychlorinated dibenzo-p-dioxins and dibenzofurans in the typical industrial areas of Tangshan City, China.

    PubMed

    Ren, Zhiyuan; Zhang, Bing; Lu, Pu; Li, Cheng; Gao, Lirong; Zheng, Minghui

    2011-01-01

    The ambient air in vicinity of different industrial sources for PCDD/PCDFs was sampled by TSP/PM10 active samplers and passive PUF disk samplers in Tangshan City, a metropolis containing clusters of various industrial plants. The TEQ concentrations of PCDD/PCDFs ranged from 44.2 to 394.1 fg I-TEQ/m3 with an average of 169.9 fg I-TEQ/m3. 2,3,4,7,8-PeCDF was the dominant contributor to sigma TEQ, contributing 41% (12% to 55%), while 1,2,3,4,6,7,8-HpCDF, OCDD and OCDF were the major congeners for the total concentrations. The ratios of sigma PCDF/ sigma PCDD reached 2.54 on average, suggesting that de novo synthesis in thermal processes played an important role to the airborne pollution of PCDD/PCDFs. The similarities congener profiles indicated that TSP and PM10 active sampling methods are comparable for the determination of the PCDD/PCDFs in ambient air, and the ratios of concentrations determined by the two methods suggested that the PCDD/PCDFs tended to stay in fine particles. It was found that 2,3,7,8-TCDF and OCDD were the dominating congeners in the passive PUF disks samples. Through principal components analysis, the coke industry was suggested to be a relatively high potential emission source for PCDD/PCDFs in the ambient air of Tangshan, which was possibly formed by de novo synthesis mechanism. In this study, the atmospheric impacts to the environment from different industrial sources could be ranked as follows (from high to low): coking, iron sintering, steel making, power generation and chlorinate alkali chemical production industries.

  17. El Titulo IX y La Discriminacion por Sexo (Title IX and Sex Discrimination).

    ERIC Educational Resources Information Center

    Office for Civil Rights (ED), Washington, DC.

    Title IX of the Education Amendments of 1972 protects people from discrimination based on sex in education programs or activities that receive Federal financial assistance. This brochure outlines the responsibilities of education programs and activities covered by Title IX, the responsibilities of the Office for Civil Rights (OCR) in enforcing…

  18. Looking for a Job: Step by Step = Buscando Trabajo: Paso por Paso.

    ERIC Educational Resources Information Center

    Edwards, Patricia

    This bilingual document provides guidelines and learning activities to assist migrant workers in looking for a job. The document covers the following areas: (1) a checklist providing an overview of job search skills; (2) developing a fact sheet of personal information; (3) listing good work qualities; (4) identifying references and securing…

  19. Luchando por una educacion: A Qualitative Understanding of Undocumented Latina/o College Student Motivation

    ERIC Educational Resources Information Center

    Navarro, Elvia Lorena

    2013-01-01

    The current qualitative study explored the factors and resources that motivate undocumented Latino/a college students to persist in higher education. Through the data obtained from the four qualitative open-ended survey questions, a content analysis revealed specific codes, themes, and subthemes addressing the factors and resources that motivate…

  20. Enfermedad diarreica aguda por Escherichia coli patógenas en Colombia

    PubMed Central

    Gómez-Duarte, Oscar G.

    2014-01-01

    Resumen Las cepas de E. coli patógenas intestinales son causas importantes de la enfermedad diarreica aguda (EDA) en niños menores de 5 años en América Latina, África y Asia y están asociadas a alta mortalidad en niños en las comunidades más pobres de África y el Sudeste Asiático. Estudios sobre el papel de las E. coli patógenas intestinales en la EDA infantil en Colombia y otros países de América Latina son limitados debido a la carencia de ensayos para detección de estos patógenos en los laboratorios clínicos de centros de salud. Estudios recientes han reportado la detección de E. coli patógenas intestinales en Colombia, siendo la E. coli enterotoxigénica la cepa más frecuentemente asociada a diarrea en niños menores de 5 años. Otros patógenos detectados en estos pacientes incluyen las E. coli enteroagregativa, enteropatógena, productora de toxina Shiga, y de adherencia difusa. Con base en estudios que reportan la presencia de E. coli productora de toxina Shiga y E. coli enteroagregativa en carnes y vegetales en supermercados, se cree que productos alimentarios contaminados contribuyen a la transmisión de estos patógenos y a la infección del huésped susceptible. Más estudios son necesarios para evaluar los mecanismos de transmisión, el impacto en la epidemiologia de la EDA, y las pautas de manejo y prevención de estos patógenos que afectan la población pediátrica en Colombia. PMID:25491457

  1. Producao d Dijatos por Dupla Troca de Pomeron Exclusiva no Experimento D0

    SciTech Connect

    Murilo Santana Rangel

    2008-01-01

    The first search for exclusive diffractive dijet production with invariant mass ≳ 100 GeV in Run II of the Fermilab Tevatron Collider is performed. The set of data used is the Run IIa, corresponding to an integrated luminosity of 30 pb-1 of p$\\bar{p}$ collisions at √s = 1.96 TeV taken with the D0 detector. At 95% CL, an upper limit for the ratio between the number of diffractive exclusive events and the number of non diffractive events is set to be 7.5 x 10-6, excluding two of the three models proposed to explain this production.

  2. Renovando la Esperanza por una Educacion sin Exclusiones (Rekindling the Hope for an Education without Exclusion).

    ERIC Educational Resources Information Center

    Revista Interamericana de Educacion de Adultos, 2001

    2001-01-01

    Articles in this issue, written in Spanish, focus on the following: current status and outlook of youth and adult education; opening statement of the 50th anniversary commemoration; regional framework for the education of youth and adults in Latin America and the Caribbean; interculturalism and the education of youth and adults; participation of…

  3. Incorporating the viewer's point of regard (POR) in gaze-contingent virtual environments

    NASA Astrophysics Data System (ADS)

    Duchowski, Andrew T.

    1998-04-01

    Awareness of the viewer's gaze position in a virtual environment can lead to significant savings in scene processing if fine detail information is presented `just in time' only at locations corresponding to the participant's gaze, i.e., in a gaze-contingent manner. This paper describes the evolution of a gaze-contingent video display system, `gcv'. Gcv is a multithreaded, real-time program which displays digital video and simultaneously tracks a subject's eye movements. Treating the eye tracker as an ordinary positional sensor, gcv's architecture shares many similarities with contemporary virtual environment system designs. Performance of the present system is evaluated in terms of (1) eye tracker sampling latency and video transfer rates, and (2) measured eye tracker accuracy and slippage. The programming strategies developed for incorporating the viewer's point-of-regard are independent of proprietary eye tracking equipment and are applicable to general gaze- contingent virtual environment designs.

  4. Phantom of RAMSES (POR): A new Milgromian dynamicsN-body code

    NASA Astrophysics Data System (ADS)

    Lüghausen, Fabian; Famaey, Benoit; Kroupa, Pavel

    2015-02-01

    Since its first formulation in 1983, Milgromian dynamics (MOND) has been very successful in predicting the gravitational potential of galaxies from the distribution of baryons alone, including general scaling relations and detailed rotation curves of large statistical samples of individual galaxies covering a large range of masses and sizes. Most predictions however rely on static models, and only a handful of N-body codes have been developed over the years to investigate the consequences of the Milgromian framework for the dynamics of complex evolving dynamical systems. In this work, we present a new Milgromian N-body code, which is a customized version of the RAMSES code (Teyssier 2002) and thus comes with all its features: it includes particles and gas dynamics, and importantly allows for high spatial resolution of complex systems due to the adaptive mesh refinement (AMR) technique. It further allows the direct comparison between Milgromian simulations and standard Newtonian simulations with dark matter particles. We provide basic tests of this customized code and demonstrate its performance by presenting N-body computations of dark-matter-free spherical equilibrium models as well as dark-matter-free disk galaxies in Milgromian dynamics.

  5. Pulsaciones excitadas por la quema de hidrógeno en enanas blancas

    NASA Astrophysics Data System (ADS)

    Camisassa, M. E.; Córsico, A. H.; Althaus, L. G.

    2016-08-01

    Recent works show that low-mass white dwarfs derived from low-metallicity progenitors, in the absence of third dredge-up episodes during the asymptotic giant branch, are born with a hydrogen envelope thick enough to make stable hydrogen shell burning the most important energy source even at low luminosities. This extra source of energy delays the cooling times of these white dwarfs. Furthermore, in this type of stars some pulsational -modes could be excited by the epsilon mechanism due to the hydrogen shell burning. Motivated by these results, we decided to explore the pulsational properties of this type of stars, aimed at constraining hydrogen shell burning and the occurrence of third dredge-up during the AGB evolution of the progenitor stars. For this purpose, we have constructed nonadiabatic pulsation models of white dwarfs from low-metallicity progenitors with . Our calculations show that some modes are excited due to hydrogen shell burning.

  6. Home before You Know It = De regres en casa en un dos por tres.

    ERIC Educational Resources Information Center

    Vida Health Communications, Inc., Cambridge, MA.

    The arrival of a newborn requires a great deal of adjustment. Intended for new and expectant parents, this booklet and companion video provide practical advice and hands-on demonstrations of the essentials of mother and baby care, from birth to the first visit to the pediatrician. The first part of the booklet, which comes in both English- and…

  7. Language and La Academia, If English Works, Por Que Se Emplea Espanol?

    ERIC Educational Resources Information Center

    Jonz, Jon G.

    1978-01-01

    The dynamics of Mexican American nationalism reflected in the publications of the Academia de la Nueva Raza and in a 1971 work by Ricardo Sanchez are examined in this article. The connection between language and ideology is discussed in the context of Chicano nationalist writing. (GC)

  8. PREJUICIO Y DISTANCIA SOCIAL HACIA PERSONAS HOMOSEXUALES POR PARTE DE JÓVENES UNIVERSITARIOS

    PubMed Central

    Fernández Rodríguez, María del C.; Squiabro, José Calderón

    2014-01-01

    Se realizó un estudio descriptivo transversal con el propósito de explorar actitudes de rechazo y distancia social hacia las personas gays y lesbianas (GL) en 565 universitarios. Se utilizó una escala para medir Prejuicio y otra escala para medir Distancia Social. Los participantes reflejaron niveles moderados de prejuicio y distancia social (DS) hacia las personas gays y lesbianas. Los varones (M=104.5, DT= 27.47) mostraron significativamente más prejuicio que las mujeres (M=98.8, DT= 23.41). Los hombres (M=22.7, DT= 7.00) mostraron significativamente mayor DS que las mujeres (M=21.1, DT= 5.41). Las personas que asisten con regularidad a la iglesia mostraron más prejuicio y DS que los que no asisten. Se analiza importancia de incluir el tema de la diversidad sexual a través del currículo para desmontar prejuicios hacia la comunidad homosexual. PMID:25606066

  9. Evolución de una protuberancia observada por el HASTA

    NASA Astrophysics Data System (ADS)

    Luoni, M. L.; Francile, C.

    Prominence eruptions are one of the most spectacular manifestations of solar activity; in addition to flares and coronal mass ejections. Both filaments and prominences are chromospheric material suspended in the corona by the magnetic field. Hence their importance as tracers of field ejections. Some parts of their magnetic structure are not well understood; especially with regard to the loss of stability. On 06 December 2010 the H-Alpha Telescope for Argentina (HASTA) observed a prominence in the eastern solar limb including when part of it was ejected. In this paper the evolution of the filament is analyzed; its structure before and after the eruption; determining parameters that characterize it from HASTA data. FULL TEXT IN SPANISH

  10. El Libro de la Escritura por Pinguino Tinto (The Writing Book, by Inky Penguin).

    ERIC Educational Resources Information Center

    Padgett, Ron

    Presented completely in Spanish and intended for elementary level students, this book offers 12 writing ideas and several suggestions on how students can make a book using their writing. Each writing idea is presented with a brief description (addressed to the student), several examples of student writing, and a blank page on which to write.…

  11. Teaching Probability for Conceptual Change (La Ensenanza de la Probabilidad por Cambio Conceptual).

    ERIC Educational Resources Information Center

    Castro, Cesar Saenz

    1998-01-01

    Presents a theoretical proposal of a methodology for the teaching of probability theory. Discusses the importance of the epistemological approach of Lakatos and the perspective of the conceptual change. Discusses research using a proposed didactic method with Spanish high school students (N=6). Concludes that significant differences on all…

  12. Master equipment list 500 CFM portable exhauster POR-005 skid C

    SciTech Connect

    KRISKOVICH, J.R.

    1999-07-08

    The Master Equipment List (MEL) lists all the major components of the 500 cfm exhauster PORO5. The purpose of this Master Equipment List is to provide basic information and references to other documents for the listed components.

  13. "Por Los Ojos De Madres": Latina Mothers' Understandings of College Readiness

    ERIC Educational Resources Information Center

    Cortez, Laura Jean; Martinez, Melissa Ann; Sáenz, Victor B.

    2014-01-01

    In this study, data from six focus groups with 30 Latina mothers in South Texas were analyzed utilizing a "funds of knowledge" approach to uncover their understandings of college readiness and their role in ensuring their children are college ready. Findings indicate that Latina mothers perceived college readiness in a holistic fashion,…

  14. Neuropatía periférica inducida por quimioterapia

    Cancer.gov

    Artículo sobre un efecto secundario de la quimioterapia que causa dolor y malestar en las manos y los pies. También incluye información sobre los esfuerzos para mejorar las opciones de detección, tratamiento y prevención.

  15. Ensenando El Espanol por Medio de Accion (Teaching Spanish through Action).

    ERIC Educational Resources Information Center

    Segal, Bertha

    A teaching guide containing 102 elementary to intermediate level Spanish lessons is presented. The lessons are based on the Total Physical Response technique of second language teaching. They follow the stages of first language acquisition: listening, speaking, and reading. Each of the ten units contains a list of new vocabulary words, individual…

  16. Sources and fate of polychlorinated dibenzodioxins, dibenzofurans and related compounds in human environments.

    PubMed Central

    Tiernan, T O; Taylor, M L; Garrett, J H; VanNess, G F; Solch, J G; Wagel, D J; Ferguson, G L; Schecter, A

    1985-01-01

    Several of the major incidents resulting in potential human exposures to polychlorinated dibenzodioxins (PCDDs) and/or polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and related compounds which have occurred in the U.S. in recent periods have resulted from improper disposal of hazardous chemical wastes. Prominent examples of such environmental contamination episodes are the Love Canal, into which ton quantities of chlorinated organic compounds containing substantial concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were deposited; numerous sites in the State of Missouri which were contaminated by the dumping of chlorinated organic wastes containing various PCDDs and possibly PCDFs, and PCBs; and the environs of a 2,4-D/2,4,5-T manufacturing plant site in Arkansas, which were contaminated with PCDDs. Environmental assessments of such sites have revealed extensive contamination of soils, waterways, fish and other biological species with these toxic compounds, which in turn could lead to human exposures. Other recently identified sources of PCDDs, PCDFs and related compounds in human environments include stack effluents from municipal refuse incineration, and fires and explosions involving electrical devices containing PCBs and polychlorinated benzenes. Data obtained in assessments of such incidents are presented, and the implications of these findings with respect to the distribution and persistence of PCDDs, PCDFs and related chemicals in the environment and possible effects on humans are discussed. PMID:3921357

  17. MECHANISTIC STEPS IN THE PRODUCTION OF PCDD AND PCDF DURING WASTE COMBUSTION

    EPA Science Inventory

    Research has shown that synthesis of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) during municipal waste combustion can proceed through a three step mechanism including 1) production of Cl2 from a metal-catalyzed reaction of HCl a...

  18. Polychlorinated dibenzo-p-dioxins, dibenzofurans, and polychlorinated biphenyls in human tissues, meat, fish, and wildlife samples from India.

    PubMed

    Kumar, K S; Kannan, K; Paramasivan, O N; Shanmuga Sundaram, V P; Nakanishi, J; Masunaga, S

    2001-09-01

    Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and non- and mono-ortho-substituted polychlorinated biphenyls (dioxin-like PCBs) were measured in tissues of humans, fishes, chicken, lamb, goat, predatory birds, and Ganges River dolphins collected from various locations in India. PCDDs/DFs were found in most of the samples analyzed with the liver of spotted owlet containing the highest concentration of 3,300 pg/g, fat wt. 2,3,7,8-Substituted PCDDs and PCDFs were found in human fattissues at concentrations ranging from 170 to 1,300 pg/g, fat wt. Concentrations of PCDDs were generally greaterthan those of PCDFs in human tissues, fishes, animal fat, and dolphin. Among fishes, meat, and wildlife samples analyzed, concentrations of PCDDs/DFs were found in the following order: country chicken < goat/lamb fat < fishes < river dolphins < predatory birds. Hepta-CDDs and OCDD were the major PCDD homologues found in humans, fishes, meat products, and dolphins. 2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents of PCDDs/DFs were greater than those of PCBs in selected fish, dolphin, and human samples. To our knowledge, this is the first report of PCDDs and PCDFs in human tissues, fishes, meat, and wildlife collected from India. PMID:11563645

  19. FRAMEWORK FOR APPLICATION OF THE TOXICITY EQUIVALENCE METHODOLOGY FOR POLYCHLORINATED DIOXINS, FURANS, AND BIPHENYLS IN ECOLOGICAL RISK ASSESSMENT

    EPA Science Inventory

    Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenols (PCBs) commonly occur as complex mixtures in the environment, including in animal tissues. For more than a decade the USEPA and other organizations have estimated the combined risks that such mixtures...

  20. EFFECT OF SOOT AND COPPER COMBUSTOR DEPOSITS ON DIOXIN EMISSIONS

    EPA Science Inventory

    An experimental study was conducted to investigate the effects of residual soot and copper combustor deposits on the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) during the combustion of a chlorinated waste. In a bench-scale set...

  1. Dioxins, dioxin-like compounds, and PBDEs in the U.S. domestic meat supply: trends and levels 2003 to 2013

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the mid-1990s, 2002-2003, 2007-2008, and again in 2012-2013 the U.S. Department of Agriculture (USDA) conducted statistical surveys for dioxin and dioxin-like compound (PCDDs, PCDFs, and PCBs) residues in domestic meat and poultry. The surveys were conducted to determine background levels of diox...

  2. Dioxin, furan, PCB, and PBDE levels in U.S. foods: Survey trends and consumer exposure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS) and Food Safety and Inspection Service (USDA-FSIS) have conducted statistical surveys for dioxins (PCDDs, PCDFs, and PCBs) and polybrominated diphenyl ethers every 5 years since the mid-1990s (mid-1990s, 2002-3, 2007-8). I...

  3. Aerosat sampling of PCDD/PCDF emissions from the Gulf oil spill in situ burns

    EPA Science Inventory

    Emissions from the in situ burning of oil in the Gulf of Mexico after the catastrophic failure of the Deepwater Horizon drilling platform were sampled for polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/PCDFs). A battery-operated instrument package was lo...

  4. A Survey of Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans and Co-planar Polychlorinated Biphenyls in U.S. Meat and Poultry, 2007-2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A statistically-based survey of dioxins and dioxin-like compounds in domestic meat and poultry was conducted by the U.S. Department of Agriculture (USDA) from September 2007 to September 2008. Seventeen toxic polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and three coplanar pol...

  5. THE EFFECT OF METAL CATALYSTS ON THE FORMATION OF POLYCHLORINATED DIBENZO-P-DIOXIN AND POLYCHLORINATED DIBENZOFURAN PRECURSORS

    EPA Science Inventory

    The catalytic effects of copper and iron compounds were examined for their behavior in promoting formation of chlorine (Cl2), the major chlorinating agent of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), in an environment simulati...

  6. DIBENZO-P-DIOXINS IN THE ENVIRONMENT FROM CERAMICS AND POTTERY PRODUCED FROM BALL CLAY MINED IN THE U.S.

    EPA Science Inventory

    Processed ball clay samples used in the production of ceramics and samples of the ceramic products were collected and analyzed for the presence and concentration of the 2,3,7,8-Cl substituted polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs). The processed ball clay had...

  7. FORMATION OF POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS FROM A MIXTURE OF CHLOROPHENOLS OVER FLY ASH: INFLUENCE OF WATER VAPOR

    EPA Science Inventory

    To offer a polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) parameter for plant operation control, the on-line estimation of PCDD/Fs emissions by surrogates like chlorophenols is useful. Formation of PCDD/Fs over fly ash was studied in an isothermal (310 degree...

  8. An automated HPLC method for the fractionation of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans in fish tissue on a porous graphitic carbon column

    USGS Publications Warehouse

    Echols, Kathy R.; Gale, Robert W.; Tillitt, Donald E.; Schwartz, Ted R.; O'Laughlin, Jerome

    1997-01-01

    The Ah (aryl-hydrocarbon) hydroxylase-receptor active polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were fractionated by an automated high-performance liquid chromatography (HPLC) system using the Hypercarb™ porous graphitic carbon (PGC) column. This commercially available column was used to fractionate the di-, mono-, and non-ortho PCBs into three fractions for gas chromatography (GC)/electron capture detection analysis, and a fourth fraction containing the PCDDs/PCDFs for GC/mass spectrometry analysis. The recoveries of the PCBs ranged from 68 to 96%, and recoveries of the PCDDs/PCDFs ranged from 74 to 123%. The PGC column has the advantage of faster separations (110 min versus 446 min) and less solvent use (275 ml versus 1,100 ml) compared with automated fractionation of these compounds on activated carbon (PX-21), while still affording good separation of the classes. The PGC column may have an advantage over the pyrenyl-based HPLC method because it has a greater loading capacity (400 μg total PCBs versus 250 μg). Overall, the PGC is a standard column that provides reproducible fractionation of PCDD/PCDFs and PCBs for analytical measurement in environmental samples.

  9. EVALUATION OF THE FULL-SCALE BASE CATALYZED DECOMPOSITION PROCESS (BCDP) UNIT LOCATED IN GUAM

    EPA Science Inventory

    This report summarizes performance data collected in February 1997 on the removal of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) from soil fed to a first-stage rotary kiln reactor of the Base Catalyzed Dec...

  10. AN ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA) FOR DETERMINING DIOXINS IN SEDIMENT AND SOIL SAMPLES

    EPA Science Inventory

    The dioxins comprise a family of compounds chemically referred to as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The most toxic of these compounds is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a known human carcinogen. Dioxins are formed ...

  11. 75 FR 35712 - National Pollutant Discharge Elimination System (NPDES): Use of Sufficiently Sensitive Test...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... Pulp and Paper Mills'' (referred to as the 304(l) Guidance, March 15, 1989, available at http://www.epa... Regulation of Discharges of PCDDs and PCDFs from Pulp and Paper Mills to Waters of the United States'' (the..., footnotes to table 2 of EPA Method 1624 and table 3 of EPA Method 1625 (49 FR 43234, October 26, 1984);...

  12. Sources and fate of polychlorinated dibenzodioxins, dibenzofurans and related compounds in human environments.

    PubMed

    Tiernan, T O; Taylor, M L; Garrett, J H; VanNess, G F; Solch, J G; Wagel, D J; Ferguson, G L; Schecter, A

    1985-02-01

    Several of the major incidents resulting in potential human exposures to polychlorinated dibenzodioxins (PCDDs) and/or polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and related compounds which have occurred in the U.S. in recent periods have resulted from improper disposal of hazardous chemical wastes. Prominent examples of such environmental contamination episodes are the Love Canal, into which ton quantities of chlorinated organic compounds containing substantial concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were deposited; numerous sites in the State of Missouri which were contaminated by the dumping of chlorinated organic wastes containing various PCDDs and possibly PCDFs, and PCBs; and the environs of a 2,4-D/2,4,5-T manufacturing plant site in Arkansas, which were contaminated with PCDDs. Environmental assessments of such sites have revealed extensive contamination of soils, waterways, fish and other biological species with these toxic compounds, which in turn could lead to human exposures. Other recently identified sources of PCDDs, PCDFs and related compounds in human environments include stack effluents from municipal refuse incineration, and fires and explosions involving electrical devices containing PCBs and polychlorinated benzenes. Data obtained in assessments of such incidents are presented, and the implications of these findings with respect to the distribution and persistence of PCDDs, PCDFs and related chemicals in the environment and possible effects on humans are discussed. PMID:3921357

  13. Sources and fate of polychlorinated dibenzodioxins, dibenzofurans and related compounds in human environments

    SciTech Connect

    Tiernan, T.O.; Taylor, M.L.; Garrett, J.H.; VanNess, G.F.; Solch, J.G.; Wagel, D.J.; Ferguson, G.L.; Schecter, A.

    1985-02-01

    Several of the major incidents resulting in potential human exposures to polychlorinated dibenzodioxins (PCDDs) and/or polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and related compounds which have occurred in the U.S. in recent periods have resulted from improper disposal of hazardous chemical wastes. Prominent examples of such environmental contamination episodes are the Love Canal, into which ton quantities of chlorinated organic compounds containing substantial concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were deposited; numerous sites in the State of Missouri which were contaminated by the dumping of chlorinated organic wastes containing various PCDDs and possibly PCDFs, and PCBs; and the environs of a 2,4-D/2,4,5-T manufacturing plant site in Arkansas, which were contaminated with PCDDs. Environmental assessments of such sites have revealed extensive contamination of soils, waterways, fish and other biological species with these toxic compounds, which in turn could lead to human exposures. Other recently identified sources of PCDDs, PCDFs and related compounds in human environments include stack effluents from municipal refuse incineration, and fires and explosions involving electrical devices containing PCBs and polychlorinated benzenes. Data obtained in assessments of such incidents are presented, and the implications of these findings with respect to the distribution and persistence of PCDDs, PCDFs and related chemicals in the environment and possible effects on humans are discussed.

  14. Adsorption of polychlorinated dibenzo-p-dioxins/dibenzofurans on activated carbon from hexane.

    PubMed

    Zhou, Xu-Jian; Buekens, Alfons; Li, Xiao-Dong; Ni, Ming-Jiang; Cen, Ke-Fa

    2016-02-01

    Activated carbon is widely used to abate dioxins and dioxin-like compounds from flue gas. Comparing commercial samples regarding their potential to adsorb dioxins may proceed by using test columns, yet it takes many measurements to characterise the retention and breakthrough of dioxins. In this study, commercial activated carbon samples are evaluated during tests to remove trace amounts of dioxins dissolved in n-hexane. The solution was prepared from fly ash collected from a municipal solid waste incinerator. The key variables selected were the concentration of dioxins in n-hexane and the dosage of activated carbon. Both polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) showed very high removal efficiencies (94.7%-98.0% for PCDDs and 99.7%-99.8% for PCDFs). The presence of a large excess of n-hexane solvent had little effect on the removal efficiency of PCDD/Fs. The adsorbed PCDD/Fs showed a linear correlation (R(2) > 0.98) with the initial concentrations. Comparative analysis of adsorption isotherms showed that a linear Henry isotherm fitted better the experimental data (R(2) = 0.99 both for PCDDs and PCDFs) than the more usual Freundlich isotherm (R(2) = 0.88 for PCDDs and 0.77 for PCDFs). Finally, the results of fingerprint analysis indicated that dioxin fingerprint (weight proportion of different congeners) on activated carbon after adsorption did not change from that in hexane.

  15. New QSAR models for polyhalogenated aromatics

    SciTech Connect

    Nevalainen, T.; Kolehmainen, E. . Dept. of Chemistry)

    1994-10-01

    Electronic properties of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and polychlorinated diphenyl ethers (PCDEs) were calculated using the semi-empirical AM 1 method. The calculated electronic descriptions--the energy of the lowest unoccupied molecular orbital (E[sub LUMO]), the energy of the highest occupied molecular orbital (E[sub HOMO]), the E[sub LUMO]-E[sub HOMO] gap (dE), and molecular polarizability--are related to the Ah receptor binding affinity values of PCDDs, PCDFs, and PCBs and immunotoxicity values for PCDEs. The quantitative structure-activity relationships (QSARs) based on chlorine substitution patterns were also constructed, and they proved to be very predictive for Ah receptor binding. Significant correlations of the electronic factors were found between the dE and Ah receptor binding affinities for PCDDs, PCDFs, and PCBs and for immunotoxicity of PCDEs. A combination of descriptors E[sub LUMO] and the total number of chlorine atoms attached to a molecule (n[sub Cl]) gives significant correlation for the Ah receptor binding of PCDFs and for immunotoxicity of PCDEs. Hydrophobicity values taken from the literature were shown to be non-significant for toxicity prediction of these polychlorinated compounds.

  16. Absence of polychlorinated dibenzodioxins and dibenzofurans after lactoperoxidase-catalyzed transformation of chlorophenols

    SciTech Connect

    Oeberg, L.G.; Swanson, S.E.

    1987-06-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) have been detected in many species and environments their bioresistance and toxicity being of great concern. PCDDs and PCDFs, or the predioxins and -furans, are formed from chlorophenols (CPs) by burning and pyrolysis by arcing and by photolysis. PCDDs and PCDFs have also been found in emissions from automobiles, municipal waste incinerators, and nickel and copper smelting. Peroxidases (POs), a group of heme-proteins, are found in many organs and organisms. They are exceptional enzymes because of low substrate specificity and multiple reaction mechanisms. This enzyme-catalyzed free radical reaction resembles reactions in pyrolysis, arcing, and photolysis. Halogenated phenols are among the peroxidase substrates, and phenolic substrates have been found to yield dibenzodioxin- and dibenzofuran like products. The question then arose whether CP's in peroxidase-mediated reactions could yield chlorinated dibenzodioxins and dibenzofurans. Since no-one has yet reported a biological formation of PCDDs and PCDFs the authors have analyzed the rpdoct mixture from the lactoperoxidase-catalyzed oxidation of some chlorophenols.

  17. Emissions from Open burning of Used Agricultural Pesticide Containers

    EPA Science Inventory

    Emissions from simulated open burning of used agricultural pesticide containers were sampled for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), polycyclic aromatic hydrocarbon compounds (PAHs), and particle matter (PM10 and PM2.5). Clean high density polyethyl...

  18. H4IIE hepatoma cell bioassay-derived 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in colonial fish-eating waterbird eggs from the Great Lakes

    SciTech Connect

    Tillitt, D.E.; Ankley, G.T.; Verbrugge, D.A.; Giesy, J.P.; Ludwig, J.P.

    1991-01-01

    Fish-eating waterbirds from the Great Lakes of North America have shown symptoms of poisoning similar to those observed in laboratory exposures of various avian species to planar halogenated hydrocarbons(PHHs). PHHs, include among others, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) and have been implicated in some of the reproductive problems of Great Lakes waterbirds.

  19. DETERMINATION OF THE VAPOR PRESSURES OF SELECT POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS AT 75–275°C

    EPA Science Inventory

    Vapor pressures were determined for several polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) at 75–275°C, extending the available literature data to more relevant temperature regions and providing the first experimental data for 2,3,7...

  20. EXPERIMENTAL AND MODELING STUDY OF DE NOVO FORMATION OF PCDD/PCDF ON MSW FLY ASH

    EPA Science Inventory

    The effect of sulfur dioxide (SO2) on formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) has been studied in an entrained-flow reactor under simulated waste combustion conditions. A chlorination model based on conditional probability ...

  1. Passive Sampling Provides Evidence for Neward Bay as a Source of Polychlorinated Dibenzo-p-Dioxins and Furans to the New York/New Jersey, USA, Atmosphere

    EPA Science Inventory

    Freely dissolved and gas phase polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were measured in the water column and atmosphere at five locations within Newark Bay (New Jersey, USA) from May 2008 to August 2009 with polyethylene (PE) passive ...

  2. EXTENSION OF U.S. EPA METHODS 0023A/8290 TO INCLUDE 13C12-LABELLED MONO-, DI-, AND TRI-CHLORINATED DIBENZO-P-DIOXIN AND DIBENZOFURAN STANDARDS

    EPA Science Inventory

    Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are typically reported only in terms of the tetra-through octa-CDD/CDF isomers, either as homologue sums or as subsets thereof. This practice is common because the toxic isomers ...

  3. THE CONCENTRATION AND DISTRIBUTION OF 2,3,7,8-DIBENZO-P-DIOXINS / - FURANS IN CHICKENS

    EPA Science Inventory

    The concentrations of 2,3,7,8-Cl substituted dibenzo-p-dioxins/-furans (PCDDs/PCDFs) were determined in the edible tissues of whole chicken fryers and compared with the values found in their abdominal fat. The values are presented both on a whole weight basis and on a lipid-adju...

  4. CONTROL OF DIOXIN, FURAN, AND MERCURY EMISSIONS FROM MUNICIPAL WASTE COMBUSTORS

    EPA Science Inventory

    There is a significant public and scientific concern over the potential risks of air pollution emissions from municipal waste combustors (MWCs). The primary pollutants of concern are polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), and mercury (Hg). Depending on...

  5. Journal Article: Atmospheric Measurements of CDDs, CDFs, and Coplanar PCBs in Rural and Remote Locations of the U.S. for the Years 1998-2001 from the National Dioxin Air Monitoring Network (Ndamn)

    EPA Science Inventory

    The U.S. EPA established a National Dioxin Air Monitoring Network (NDAMN) to determine background air concentrations of PCDDs, PCDFs, and cp-PCBs in rural and remote areas of the United States. Background is defined as average ambient air concentrations inferred from long-term a...

  6. Adsorption of polychlorinated dibenzo-p-dioxins/dibenzofurans on activated carbon from hexane.

    PubMed

    Zhou, Xu-Jian; Buekens, Alfons; Li, Xiao-Dong; Ni, Ming-Jiang; Cen, Ke-Fa

    2016-02-01

    Activated carbon is widely used to abate dioxins and dioxin-like compounds from flue gas. Comparing commercial samples regarding their potential to adsorb dioxins may proceed by using test columns, yet it takes many measurements to characterise the retention and breakthrough of dioxins. In this study, commercial activated carbon samples are evaluated during tests to remove trace amounts of dioxins dissolved in n-hexane. The solution was prepared from fly ash collected from a municipal solid waste incinerator. The key variables selected were the concentration of dioxins in n-hexane and the dosage of activated carbon. Both polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) showed very high removal efficiencies (94.7%-98.0% for PCDDs and 99.7%-99.8% for PCDFs). The presence of a large excess of n-hexane solvent had little effect on the removal efficiency of PCDD/Fs. The adsorbed PCDD/Fs showed a linear correlation (R(2) > 0.98) with the initial concentrations. Comparative analysis of adsorption isotherms showed that a linear Henry isotherm fitted better the experimental data (R(2) = 0.99 both for PCDDs and PCDFs) than the more usual Freundlich isotherm (R(2) = 0.88 for PCDDs and 0.77 for PCDFs). Finally, the results of fingerprint analysis indicated that dioxin fingerprint (weight proportion of different congeners) on activated carbon after adsorption did not change from that in hexane. PMID:26476048

  7. Accumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans in liver of control laboratory rats.

    PubMed

    Vanden Heuvel, J P; Clark, G C; Tritscher, A m; Lucier, G W

    1994-10-01

    Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls belong to a class of compounds, the polyhalogenated aromatic hydrocarbons (PHAHs), which are ubiquitous environmental contaminants. Due to the existence of a common mechanism of action, i.e., binding to the Ah receptor, the activity of members of this class of compounds is generally expressed relative to the prototypical 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as toxic equivalency factors (TEFs). In the present studies we examined the presence of liver of untreated PCDFs in standard laboratory feed and in the liver of untreated rats at three different ages (60, 140, and 200 days) in terms of concentration and in toxic equivalents (TEQs, TEF x concentration). Feed was shown to contain trace amounts of PCDDs and PCDFs and control rat liver was shown to contain several PCDD and PCDF congeners in terms of concentration of congener and concentration of TEQs contributed by that congener. The total concentration of TEQs increased with increasing age in rat liver, going from 20 ppt TEQ at 60 days to 78 ppt TEQ at 200 days of age. This accumulation in dioxin-like activity was due primarily to PCDFs. In particular the congener 2,3,4,7,8-pentachlorodibenzofuran accrued in untreated rat liver accounting for approximately 80% of the total TEQ at 200 days of age. These studies affirm the pervasive presence of PHAHs and suggest prudence in evaluating chronic rat studies in which interference from background levels of PCDDs and PCDFs may be a factor.

  8. Polychlorinated dibenzo-p-dioxins and dibenzofurans in sediments and biota of the Saguenay Fjord and the St. Lawrence Estuary

    SciTech Connect

    Brochu, C.; Moore, S.; Pelletier, E.

    1995-12-31

    Sediment samples and marine organisms were collected in the Saguenay Fjord and at two selected sites of the St. Lawrence Estuary in 1991. Total PCDDs and total PCDFs ranged from 22 to 352 ng kg{sup {minus}1} and 29 to 188 ng kg{sup {minus}1}, respectively in Saguenay sediments, while total PCDFs reached, 287 ng kg{sup {minus}1} in Baie des Anglais, a small and deep bay of the St. Lawrence Estuary impacted by PCBs during the 1970s. All biological samples contained detectable amounts of chlorinated dibenzodioxins and dibenzofurans, apart from the North Atlantic cod (Gadus morhua). The highest concentrations (up to 59.7 ng kg{sup {minus}1} total PCDFs and 2.54 ng kg{sup {minus}1} 2,3,7,8T4CDD Equivalent (TCDD TEQ)) were observed in crab (Chionoecetes opilio) caught in Saguenay Fjord and in crab and whelk (Buccinwn undatwn) collected in Baie des Anglais. Nordic shrimp (Pandalus borealis) is less contaminated with a maximum total PCDDs and PCDFs concentration of 14.0 ng kg{sup {minus}1} and TCDD TEQ never exceeding 0.7 ng kg{sup {minus}1}. Greenland halibut (Reinhardtius hippoglossoides) caught in the Saguenay Fjord contained only 2,3,7,8 substituted congeners in their tissues leading to a low average TCDD TEQ of 1.66 ng kg{sup {minus}1}. Based upon this first series of results, benthic organisms and fish from the Saguenay Fjord and the north shore of the St. Lawrence Estuary are exposed to low levels of PCDDs and PCDFs, and carry tissue concentrations well below international guidelines for fisheries products.

  9. Emissions of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans from the open burning of household waste in barrels

    SciTech Connect

    Lemieux, P.M.; Lutes, C.C.; Abbott, J.A.; Aldous, K.M.

    2000-02-01

    Backyard burning of household waste in barrels is a common waste disposal practice for which pollutant emissions have not been well characterized. This study measured the emissions of several pollutants, including polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs), from burning mixtures designed to simulate waste generated by a recycling and a nonrecycling family in a 208-L (55-gal) burn barrel at the EPA's Open Burning Test Facility. This paper focuses on the PCDD/PCDF emissions and discusses the factors influencing PCDD/PCDF formation for different test burns. Four test burns were made in which the amount of waste placed in the barrel varied from 6.4 to 13.6 kg and the amount actually burned varied from 46.6% to 68.1%. Emissions of total PCDDs/PCDFs ranged between 0.0046 and 0.48 mg/kg of waste burned. Emissions are also presented in terms of 2,3,7,8-TCDD toxic equivalents. Emissions of PCDDs/PCDFs appear to correlate with both copper and hydrochloric acid emissions. The results of this study indicate that backyard burning emits more PCDDs/PCDFs on a mass of refuse burned basis than various types of municipal waste combustors (MWCs). Comparison of burn barrel emissions to emissions from a hypothetical modern MWC equipped with high-efficiency flue gas cleaning technology indicates that about 2--40 households burning their trash daily in barrels can produce average PCDD/PCDF emissions comparable to a 182,000 kg/day (200 ton/day) MWC facility. This study provides important data on a potentially significant source of emissions of PCDDs/PCDFs.

  10. A review of dioxin releases to land and water in the UK.

    PubMed

    Dyke, P H; Foan, C; Wenborn, M; Coleman, P J

    1997-11-27

    UK government policy is to identify and control the sources of some chlorinated organic compounds including polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), often known collectively as dioxins. This requires the gathering of information on the scale of releases of PCDD/PCDFs to all environmental media. While a number of recent studies have produced inventories of PCDD/PCDF emissions to air, this study, commissioned by Her Majesty's Inspectorate of Pollution (HMIP--now part of the Environment Agency), is the first attempt at producing a comprehensive UK inventory of emissions of dioxins to land and water from industrial and non-industrial processes. Release of PCDD/PCDFs in wastes taken to landfill are included under the definitions or releases to land used by the Environment Agency. Assembly of the inventory, particularly for releases to water, was severely hampered by lack of data from the UK or overseas; further work is required to remedy the data gaps and deficiencies revealed. The inventory puts total quantified releases to land at 1500-12,000 g toxic equivalent quantities (TEQ) per year--significantly more than releases to air or water. This is as expected, given the nature of the processes that form PCDD/PCDFs and their propensity to bind tightly to solid materials. The bulk of releases to land are to landfills rather than the open environment. From the data available, the open use of chemicals (including the disposal of wood treated with PCP), the manufacture of pesticides, the incineration of municipal solid waste (MSW) and accidental fires appear to be the largest contributors. The processes with greatest potential for releases to water appear to be the open use of chemicals, sewage treatment, disposal of waste oil, accidental fires, production of pesticides and chlorophenols and chemical waste incineration. In addition, the run-off from roads may be a significant source of releases as this is untreated. For the majority

  11. La trama celeste: por qué educar en astronomía. Una oportunidad de aprendizajes múltiples

    NASA Astrophysics Data System (ADS)

    García, B.

    2016-08-01

    Astronomy education at all levels has been an issue addressed by the International Astronomical Union as part of its 2010--2020 plan. The content on astronomical topics are in the curriculum at primary and secondary levels worldwide. Being a cross-discipline, astronomy is also a science that allows to introduce students to the study of the nature in a non-confrontational way: no one is indifferent to their concepts and discoveries. The International Astronomical Union, through its Commission on Education and Development of Astronomy, has implemented, sponsored and carried out over the past five years two special programs, one about didactics of astronomy for teachers of middle level and another one for the transmission of astronomical topics for the disabled. In this presentation, achievements and impact of these programs are shared.

  12. Distribución superficial de impactos en Iapetus originada por el remanente de una colisión

    NASA Astrophysics Data System (ADS)

    Zoppetti, F. A.; Leiva, A. M.; Briozzo, C. B.

    2015-08-01

    By means of Circular Restricted Three Body Problem Saturn--Iapetus, we analize potential impact distributions on the surface of Iapetus, originated from considering a low-energy population generated as remnants of a collisional event occurred in the past on the surface of this satellite. The results are analized in order to offer a new approach to explain the origin of the albedo dichotomy observed on Iapetus.

  13. Como ayudar a los padres a prevenir el envenenamiento por plomo (Helping Parents Prevent Lead Poisoning). ERIC Digest.

    ERIC Educational Resources Information Center

    Binns, Helen J.; Ricks, Omar Benton

    Children are at greater risk than adults for lead poisoning because children absorb lead more readily than adults, and a small amount of lead in children's bodies can do a great deal of harm. This Spanish-language Digest summarizes some of the causes and effects of childhood lead poisoning and suggests some lead poisoning prevention strategies…

  14. Reconnaissance evaluation of Honduran geothermal sites. Una evaluacion por medio de reconocimiento de seis areas geotermicas en Honduras

    SciTech Connect

    Eppler, D.; Fakundiny, R.; Ritchie, A.

    1986-12-01

    Six geothermal spring sites were selected on the basis of preliminary investigations conducted in Honduras over the last decade and were evaluated in terms of their development potential. Of the six, the Platanares and San Ignacio sites have high base temperatures and high surface fluid discharge rates and appear to have the best potential for further development as sources of electrical power. A third site, Azacualpa, has a high enough base temperature and discharge rate to be considered as a back-up, but the logistical problems involved in geophysical surveys make it less attractive than the two primary sites. Of the remaining three sites, Pavana may be a source of direct-use heat for local agricultural processing. Sambo Creek and El Olivar have either severe logistical problems that would impede further investigation and development or base temperatures and flow rates that are too low to warrant detailed investigation at this time.

  15. En otras palabras: Perfeccionamiento del espanol por medio de la traduccion (In Other Words: Perfecting Spanish Language Skills through Translation).

    ERIC Educational Resources Information Center

    Lunn, Patricia V.; Lunsford, Ernest J.

    This publication, written primarily in Spanish, is an activity book designed to teach Spanish through translation based on the theory that, in order to produce an acceptable translation, students must focus their attention on lexical and grammatical detail. The book combines incisive grammar explanations, relevant lexical information, and a wide…

  16. Monitoreo óptico de eta-Carina durante el pasaje por el periastro en 2014.6

    NASA Astrophysics Data System (ADS)

    Fernández-Lajús, E.; Salerno, N. E.; Scalia, M. C.; Ramos, X. S.; Giudici, F. N.; Gamen, R. C.

    2015-08-01

    We present the H light curves resulting from the 2013 and 2014 observing seasons of Car as well as its spectral evolution, including the latest ``event'' occurred in mid-2014. The direct CCD observations were made with the telescope ``VS Niemela'' the Observatory of La Plata, and spectroscopic observations were made with the telescope ``J. Sahade'' of Casleo, Argentina.

  17. Combustion and emissions tests of the Vicon Incinerator at Pittsfield, Massachusetts

    SciTech Connect

    Neulicht, R.; Visalli, J.

    1987-01-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) can be generated as a result of combustion of municipal solid waste (MSW). However, knowledge is limited about the incinerator design and operating conditions that cause these compounds to form and that can be adjusted to minimize or eliminate their discharge. This paper reports some of the major results of an extensive combustion/emissions testing program designed to gather data related to this topic. The testing was conducted at the VICON Resource Recovery Municipal Solid Waste Facility in Pittsfield, Massachusetts. The study focused on identifying the relationships between incinerator operating conditions, waste characteristics, combustion variables, and levels of PCDDs and PCDFs and selected other semivolatile organic compounds measures in the combustion gases.

  18. The concentration and distribution of 2,3,7,8-dibenzo-p-dioxins/-furans in chickens

    NASA Technical Reports Server (NTRS)

    Ferrario, J.; Byrne, C.

    2000-01-01

    The concentrations of the 2,3,7,8-Cl substituted dibenzo-p-dioxins/-furans (PCDDs/PCDFs) were determined in the edible tissues of whole chicken fryers and compared with the values found in their abdominal fat. The values are presented both on a whole weight basis and on a lipid adjusted basis for each tissue. While there is a marked difference in the concentration of the 2,3,7,8-dibenzo-p-dioxins in the edible tissues expressed on a whole weight basis, the lipid-adjusted concentrations of the individual dioxins were not statistically different in the various tissues. This validates the use of lipid adjusted concentrations of 2,3,7,8-PCDDs/PCDFs in abdominal fat for the determination of the presence of these compounds in different tissues.

  19. Comprehensive assessment of the specific compounds present in combustion processes. Volume 4. National estimates of emission of specific compounds from coal fired utility boiler plants. Final report

    SciTech Connect

    Lucas, R.M.; Kircher, G.W.

    1985-08-01

    Specimens were acquired from influents and effluents from seven coal-fired utility boilers. The specimens were chemically analyzed for toxic compounds in the polycyclic organic matter group. The specific target compounds were polychlorinated dibenzo(p)-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), selected polynuclear aromatic hydrocarbons (PAHs) and selected phthalates. Twelve PAH compounds and six phthalate compounds were included among the targetted compounds. Naphthalene was the most prevalent PAH compound detected. It was found in the flue gas emissions from all seven facilities. Other PAHs were also detected in the coal at all seven facilities but were only rarely detected in the other media. No PCDDs or PCDFs were detected in any of the acquired specimens. PCBs were only detected in one other media, the influent combustion air.

  20. Long-term hazards of polychlorinated dibenzodioxins and polychlorinated dibenzofurans.

    PubMed Central

    Huff, J E; Moore, J A; Saracci, R; Tomatis, L

    1980-01-01

    During January 10-11, 1978 in Lyon, France, a joint National Institute of Environmental Health Sciences/International Agency for Research on Cancer ad hoc Working Group considered and discussed the feasibility of coordinating epidemiological studies on the long-term hazards associated with the chlorinated dibenzo-p-dioxins and chlorinated dibenzofurans (PCDDs and and PCDFs). Nineteen invited scientists from eight countries presented introductory working papers summarizing the most up-to-date and relevant information available from their individual programs. This report represents the collective views and scientific opinions of the Working Group. The greater part of this document comprises epidemiological studies related to episodes of human exposures. The review begins with a brief section concerning possible routes of human exposure, an overview of the pertinent chemical characteristics, and the salient toxicological properties of the structurally similar PCDDs/PCDFs. The Working Group report ends with recommendations for future activities. PMID:6448744

  1. Polychlorinated dibenzo-p-dioxin and dibenzofuran residues in estuarine and coastal North Sea sediments: Sources and distribution

    SciTech Connect

    Evers, E.H.G.; Klamer, H.J.C.; Laane, R.W.P.M. . Ministry of Transport, Public Works and Water Management); Govers, H.A.J. . Dept. of Environmental and Toxicological Chemistry)

    1993-09-01

    Sediments from two depositional zones of the North Sea (the Wadden Sea and Oyster Grounds) and from the estuaries of the rivers Rhine, Meuse, Scheldt, Ems, and Humber were analyzed for polychlorinated dibenzofurans (PCDFs) and dibenzo-p-dioxins (PCDDs) using a congener-specific procedure. A simple grain-size correction procedure was utilized for the comparison of PCDF and PCDD concentrations in sediments from different origin. PCDFs were more widely encountered than PCDDs in all sediments, except for the Ems-Dollard and the Humber estuary. The highest concentrations were found in the outflow sediments of the rivers Rhine and Humber. Concentrations up to 2,980 ng/kg PCDFs, principally 1,2,3,4,6,7,8-HpCDF and OCDF, and up to 1,760 ng/kg PCDDs, principally OCDD, were determined in the River Rhine sediments. Principal component analysis was used to visualize the compositional changes of Rhine sediments. Principal component analysis was used to visualize the compositional changes of PCDD and PCDF profiles in the sediments. Two-dimensional projections based on sample scores from the principal component models showed a marked influence of the River Rhine on the presence of these compounds in the western Wadden Sea and the Oyster Grounds. Based on a chemometric evaluation of chromatographic profiles of these coastal, estuarine and related freshwater sediments, the authors have deduced that these compounds originate from industrial operation discharges, related to the production of chloroaliphatic compounds and the chloralkali compounds and the chloralkali industry along the River Rhine. The atmospheric deposition of combustion-generated PCDDs and PCDFs appeared significant only for remote marine environments.

  2. Comparison of the contributions of polychlorinated dibenzo-p-dioxins and dibenzofurans and other unintentionally produced persistent organic pollutants to the total toxic equivalents in air of steel plant areas.

    PubMed

    Li, Sumei; Liu, Guorui; Zheng, Minghui; Liu, Wenbin; Wang, Mei; Xiao, Ke; Li, Changliang; Wang, Yiwen

    2015-05-01

    The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and the "dioxin-like" (dl) compounds polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polybrominated dibenzo-p-dioxins (PBDDs), and dibenzofurans (PBDFs), were determined in the air samples collected from six steel plants. The toxic equivalent (TEQ) concentrations of the PCDDs, PCDFs, dl-PCBs, dl-PCNs, PBDDs, and PBDFs in the air were 0.01-0.19 pg WHO-TEQ Nm(-3), 0.01-0.69 pg WHO-TEQN m(-3), 0.001-0.089 pg WHO-TEQ Nm(-3), 0.002-0.011 pg TEQ Nm(-3), 0.004-0.02 pg TEQ Nm(-3), and 0.02-0.12 pg TEQ Nm(-3), respectively. The PCNs were the most abundant compounds (by mass concentration), contributing about 87% of the total mass concentrations of the analytes that were found in the air of the steel plant areas. The PCDFs contributed about 47% of the total TEQs, following by the PBDFs (28%) and the PCDDs (18%). The dioxin-like compounds together contributed up to 40% of the total TEQs, so their contributions to the toxic effects that could be caused by exposure to the air of the steel plant areas were significant. The congener profiles in the air were similar to the congener profiles that were found in stack gas emissions, indicating that the steelmaking plants were possible sources of the PCDDs, PCDFs, and dioxin-like compounds that were found in the air of the steel plant areas.

  3. Serum concentrations of TCDD and other dioxin-like compounds in US Air Force veterans of Operation Ranch Hand.

    PubMed

    Pavuk, Marian; Patterson, Donald G; Turner, Wayman E

    2014-05-01

    We measured serum concentrations of seven dibenzo-p-dioxin congeners (PCDDs), ten dibenzofurans (PCDFs), four non-ortho polychlorinated biphenyls (noPCBs) and six mono-ortho polychlorinated biphenyls (moPCBs) in 1950 veterans of the Vietnam War. The veterans were participants in the Air Force Health Study (AFHS) who attended the final medical examination in 2002. Blood samples were collected from 777 Ranch Hands involved in the aerial spraying of herbicides in Vietnam and a comparison group of 1173 veterans ("Comparisons") who served in Southeast Asia during the same time period. Results for moPCBs were based on a random subsample of 800 veterans. The median 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) concentrations in 2002 were 5.0 pg g(-1) lipid in Ranch Hands and 2.2 pg g(-1) lipid in Comparisons. No substantial differences were found in measured concentrations of other PCDDs, PCDFs, and noPCBs. Similarly, no substantial differences were found for moPCBs in the subsample. The median total dioxin toxic equivalent (TEQ) in Ranch Hands was 18.7 pg g(-1) lipid for PCDDs, 3.4 pg g(-1) lipid for PCDFs, and 3.2 pg g(-1) lipid for noPCBs. Median TEQs in Comparisons were 14.4 pg g(-1) lipid for PCDDs, 3.5 pg g(-1) lipid for PCDFs, and 3.3 pg g(-1) lipid for noPCBs. These TEQs, with the exception of PCDD TEQ in Ranch Hands (primarily due to elevated TCDD), were similar to or lower than those reported for similar age and gender groups in the 2001-2002 National Health and Nutrition Examination Survey (NHANES). These findings support the assumption that the Ranch Hand veterans were not more highly exposed to dioxin-like compounds other than TCDD than were Comparison veterans or the general US population. PMID:24377449

  4. Dioxin abatement strategies and mass balance at a municipal waste management plant.

    PubMed

    Abad, E; Adrados, M A; Caixach, J; Rivera, Josep

    2002-01-01

    Since the thermal management of municipal solid waste (MSW) is considered to be one of the major sources of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), the purpose of this study was to show the results of a dioxin abatement program performed in the municipal waste incineration (MWI) plant of Tarragona (NE Spain). Previously, stack gas emission levels of PCDDs/PCDFs around 3.26 ng I-TEQ/Nm3 were determined when the gas-cleaning system consisted only of an electrostatic precipitator (ESP). Decreased levels, below 0.1 ng I-TEQ/ Nm3, were observed when a new air pollution control system was installed. This new system was improved by the injection of activated carbon, which helped to lower the levels of PCDDs/PCDFs to around 0.01 ng I-TEQ/Nm3. Considering the absence of a particular impact on herbages, soils, and ambient air around the plant, as reported in previous works, and the hypothesis that a modern installation could become a sink for dioxins instead of a source, a dioxin mass balance was evaluated. The study compared in a large-scale MWI plant the levels of PCDDs/PCDFs of all input and output contributors (MSW, ambient air, stack gas emission, fly ash, and slag) forming part of the inventory collected in various monitoring campaigns. The findings revealed a remarkable homogeneity in output values (between 1.19 and 2.62 ng I-TEQ/yr) in contrast to the large variability observed in input values. In the first sampling campaign, the dioxin content in MSW was around 64.15 ng I-TEQ/kg, and a negative balance of 7.68 g I-TEQ/yr was calculated. However, in the latest campaign, levels were about 2.36 ng I-TEQ/kg MSW, resulting in a positive balance of 2.28 g I-TEQ/yr.

  5. A General Model of Dioxin Contamination in Breast Milk: Results from a Study on 94 Women from the Caserta and Naples Areas in Italy

    PubMed Central

    Rivezzi, Gaetano; Piscitelli, Prisco; Scortichini, Giampiero; Giovannini, Armando; Diletti, Gianfranco; Migliorati, Giacomo; Ceci, Roberta; Rivezzi, Giulia; Cirasino, Lorenzo; Carideo, Pietro; Black, Dennis M.; Garzillo, Carmine; Giani, Umberto

    2013-01-01

    Background: The Caserta and Naples areas in Campania Region experience heavy environmental contamination due to illegal waste disposal and burns, thus representing a valuable setting to develop a general model of human contamination with dioxins (PCDDs-PCDFs) and dioxin-like-PCBs (dl-PCBs). Methods: 94 breastfeeding women (aged 19–32 years; mean age 27.9 ± 3.0) were recruited to determine concentrations of PCDDs-PCDFs and dl-PCBs in their milk. Individual milk samples were collected and analyzed according to standard international procedures. A generalized linear model was used to test potential predictors of pollutant concentration in breast milk: age, exposure to waste fires, cigarette smoking, diet, and residence in high/low risk area (defined at high/low environmental pressure by a specific 2007 WHO report). A Structural Equation Model (SEM) analysis was carried out by taking into account PCDDs-PCDFs and dl-PCBs as endogenous variables and age, waste fires, risk area and smoking as exogenous variables. Results: All milk samples were contaminated by PCDDs-PCDFs (8.6 pg WHO-TEQ/98g fat ± 2.7; range 3.8–19) and dl-PCBs (8.0 pg WHO-TEQ/98g fat ± 3.7; range 2.5–24), with their concentrations being associated with age and exposure to waste fires (p < 0.01). Exposure to fires resulted in larger increases of dioxins concentrations in people living in low risk areas than those from high risk areas (p < 0.01). Conclusions: A diffuse human exposure to persistent organic pollutants was observed in the Caserta and Naples areas. Dioxins concentration in women living in areas classified at low environmental pressure in 2007 WHO report was significantly influenced by exposure to burns. PMID:24217180

  6. Dioxins and dibenzofurans in adipose tissue of the general US population and selected subpopulations.

    PubMed Central

    Orban, J E; Stanley, J S; Schwemberger, J G; Remmers, J C

    1994-01-01

    OBJECTIVES. The Environmental Protection Agency's National Human Adipose Tissue Survey (NHATS) was conducted in fiscal year (FY) 1987 to (1) estimate average concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in the adipose tissue of humans in the US population, (2) identify differences in average concentrations among subpopulations, and (3) compare average concentrations with those from the FY 1982 NHATS. METHODS. Population estimates of the average levels of PCDDs and PCDFs were established on the basis of 865 human adipose tissue specimens collected in FY 1987. Average levels among subpopulations were compared. RESULTS. The average concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin in the adipose tissue of the US population was 5.38 pg/g, increasing from 1.98 pg/g in children under 14 years of age to 9.40 pg/g in adults over 45. The effect of age was significant for nine compounds. Regional differences in the levels of 2,3,4,7,8-pentachlorinated dibenzofurans were statistically significant, but there were no significant differences associated with sex or race. CONCLUSIONS. The survey provides a baseline of average levels of PCDDs and PCDFs in the adipose tissue of humans in the US population. PMID:8129062

  7. A cross-sectional analysis of dioxins and health effects in municipal and private waste incinerator workers in Japan

    PubMed Central

    YAMAMOTO, Kenya; KUDO, Mitsuhiro; ARITO, Heihachiro; OGAWA, Yasutaka; TAKATA, Tsutomu

    2015-01-01

    This cross-sectional study was intended to examine health effects of 678 male workers employed during an 8-yr period from 2000 to 2007 at 36 municipal and private waste incineration plants in Japan. Blood samples were obtained for analysis of concentrations of dioxins including coplanar polychlorinated biphenyls (coplanar PCBs) and evaluation of health effects. Health effects including diabetes were surveyed via a physician’s interview or clinical data from blood samples. There was a certain difference in serum concentrations of polychlorinated dibenzofurans (PCDFs) between the incinerator workers and Japanese general population, although no differences in the concentrations of total dioxins or polychlorinated dibenzo-p-dioxins (PCDDs) were found between the two groups. A few positive correlations between serum levels of PCDDs and PCDFs and the results of laboratory and physiological tests were found, but coplanar PCBs showed significant relations with 14 parameters of the tests. The background serum levels of PCDDs, PCDFs and total dioxins were significantly associated with the prevalence of diabetes. No essential differences in serum concentrations of total dioxins and in prevalence of diabetes between our subjects and the general population suggested that the incinerator workers were marginally exposed to dioxins in the workplace without any recognizable adverse health effects. PMID:26212412

  8. Isomer pattern and elimination of dioxins in workers exposed at a municipal waste incineration plant

    PubMed Central

    YAMAMOTO, Kenya; KUDO, Mitsuhiro; ARITO, Heihachiro; OGAWA, Yasutaka; TAKATA, Tsutomu

    2015-01-01

    The aim of this study was to clarify patterns of serum concentrations of dioxins in the employees of a waste incineration plant and to estimate elimination rates and half-lives of serum dioxin isomers, and the maximum serum concentrations of dioxin isomers at the time of plant shutdown. Sixteen subjects participating 3 times or more in annual health examinations during an 8-yr period from 2000 to 2007 were recruited for this study. Serum concentrations of dioxins expressed as TEQ/g lipid decreased gradually after plant shutdown with the highest decrease observed in polychlorinated dibenzofurans (PCDFs) followed by polychlorinated deibenzo-p-dioxins (PCDDs) and then coplanar PCBs. The serum toxic equivalency (TEQ) concentrations of PCDF and PCDD congeners in the employees were higher than those in the general population survey by the Ministry of the Environment, Japan, whereas the serum concentrations of coplanar PCBs were similar to those in the general population. The estimated half-lives and elimination rates of PCDDs and PCDFs in the highly exposed workers increased compared with the moderately exposed workers. The estimated geometric mean serum concentrations of PCDDs, PCDFs and total dioxins at the time of plant shutdown were 35, 53 and 107 pg TEQ/g lipid, respectively. PMID:26118856

  9. Exposure of northern leopard frogs in the Green Bay ecosystem to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans is measured by direct chemistry but not hepatic ethoxyresorufin-O-deethylase activity

    SciTech Connect

    Huang, Y.W.; Karasov, W.H.; Patnode, K.A.; Jefcoate, C.R.

    1999-10-01

    The authors measured concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in northern leopard frogs collected from the Green Bay ecosystem and explored the catalytic activity of hepatic cytochrome P450-associated monooxygenase (P450 enzyme) as a biomarker for exposure to aryl hydrocarbon receptor (AhR) agonists. The two hypotheses tested were PCH concentrations in northern leopard frogs would be positively correlated with sediment polychlorinated hydrocarbon (PCH) levels in wetland habitats along a contamination gradient and hepatic ethoxyresorufin-O-deethylase (EROD) activity of northern leopard frogs, which is presumably mediated by aryl hydrocarbon receptor (AhR), would be positively correlated with PCH concentrations in frog carcasses from different collection sites. In 1994 and 1995, frogs from seven sites along the lower Fox River and Green Bay, USA, were assayed for hepatic EROD activities and whole carcass concentrations of PCBs, PCDDs, and PCDFs. Tissue total PCB concentrations ranging from 3 to 154 ng/g were significantly correlated with sediment PCB levels. Only one PCDD and two PCDFs at concentrations of 6 to 8 pg/g were found in the frogs collected with frog body weight and was similar among sites except for Peter's Marsh. No significant correlation was found between EROD activity and carcass PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB concentrations compared with what was required for induction in the laboratory.

  10. Declining Dioxin Concentrations in the Rhone River Basin, France, Attest to the Effectiveness of Emissions Controls.

    PubMed

    Van Metre, Peter C; Babut, Marc; Mourier, Brice; Mahler, Barbara J; Roux, Gwenaelle; Desmet, Marc

    2015-11-01

    Emission-control policies have been implemented in Europe and North America since the 1990s for polychlorodibenzodioxins (PCDDs) and furans (PCDFs). To assess the effect of these policies on temporal trends and spatial patterns for these compounds in a large European river system, sediment cores were collected in seven depositional areas along the Rhone River in France, dated, and analyzed for PCDDs and PCDFs. Results show concentrations increase in the downstream direction and have decreased temporally at all sites during the last two decades, with an average decrease of 83% from 1992 to 2010. The time for a 50% decrease in concentrations (t1/2) averaged 6.9±2.6 and 9.1±2.9 years for the sum of measured PCDDs and PCDFs, respectively. Congener patterns are similar among cores and indicate dominance of regional atmospheric deposition and possibly weathered local sources. Local sources are clearly indicated at the most downstream site, where concentrations of the most toxic dioxin, TCDD, are about 2 orders of magnitude higher than at the other six sites. The relatively steep downward trends attest to the effects of the dioxin emissions reduction policy in Europe and suggest that risks posed to aquatic life in the Rhone River basin from dioxins and furans have been greatly reduced.

  11. Evaluation of 2,3,7,8 specific congener and toxic potency of persistent polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in cetaceans from the Mediterranean Sea, Italy

    SciTech Connect

    Jimenez, B.; Gonzalez, M.J.; Jimenez, O.; Reich, S.; Eljarrat, E.; Rivera, J.

    2000-03-01

    The present study investigates individual 2,3,7,8-substituted polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) concentrations in cetaceans and assesses the PCDD and PCDF contributions to the total TCDD equivalent concentration. Liver samples of a variety of cetaceans species found stranded along the Italian coasts during the period of 1987--1992 were analyzed for PCDDs and PCDFs. The main aims were to scrutinize levels and patterns of PCDDs and PCDFs for the first time in cetaceans from the Mediterranean Sea and to estimate whether chlorinated compounds mentioned are implicated in the exceptionally high mortality of dolphins that occurred in the Mediterranean sea during 1990--1992. PCDD and PCDF profiles were dominated by congeners OCCD and OCDF. The new toxic equivalency factors recommended by WHO in 1997 were used for calculation of dioxin-like toxicity. On the basis of their previous study of PCBs, the overall TEQ calculated from the 2,3,7,8-substituted PCDDs and PCDFs do not contribute as much dioxin-like toxicity as PCBs.

  12. Evaluation of planar halogenated and polycyclic aromatic hydrocarbons in estuarine sediments using ethoxyresorufin-O-deethylase induction of H4IIE cells

    USGS Publications Warehouse

    Gale, R.W.; Long, E.R.; Schwartz, T.R.; Tillitt, D.E.

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) and planar halogenated hydrocarbons (PHHs), including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) were determined in fractionated sediment extracts from the Hudson-Raritan estuary and Newark Bay, New Jersey, USA, as part of a comprehensive risk assessment. Contributions of PCDDs/PCDFs, PCBs, and PAHs to the total toxic equivalents (TEQs) were measured using an H4IIE bioassay and calculated from instrumentally determined concentrations using international toxic equivalency factors. The H4IIE TEQs of whole and fractionated extracts were compared to calculated TEQs to investigate the applicability of the bioassay approach for evaluating 7-ethoxyresorufin-O-deethylease induction by PHHs and PAHs present together in complex mixtures. Although 2,3,7,8-tetrachlorodibenzo-p-dioxin contributed from 41 to 79% of the calculated TEQs from PCDDs/PCDFs and planar PCBs in all sediments sampled, the PAH-containing fractions accounted for >80% of the total TEQs determined either instrumentally or by bioassay. Calculated TEQs from PAHs, based on reported toxic equivalency factors for only seven PAHs, were severalfold greater than the bioassay-derived TEQs of PAH-only fractions of the sediment extracts. Significant correlations were observed between bioassay and instrumentally determined toxic equivalents in the more purified fractions but not in fractions only purified by size-exclusion or argentate chromatographies alone.

  13. Effects of regional differences in waste composition on the thermal formation of polychlorinated aromatics during incineration.

    PubMed

    Phan, Duong Ngoc Chau; Jansson, Stina; Marklund, Stellan

    2013-11-01

    Two artificial wastes (A and B) whose contents reflect regional differences in municipal solid waste composition, were used to investigate the thermal formation of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and naphthalenes (PCNs) during incineration. Flue gas samples were simultaneously collected at three ports in the post-combustion zone corresponding to flue gas temperatures of 400, 300, and 200 °C. The combustion of Waste B, which had a higher chlorine and metal content than Waste A, produced greater levels of highly-chlorinated homologues, as demonstrated by a higher degree of chlorination. The total concentrations of PCDDs, PCDFs, PCBs, and PCNs formed in the combustion of both wastes increased as temperature decreased along the convector. There were no significant differences in total concentrations between Waste A and Waste B combustion at specific temperatures, with exception of PCDFs at 400 °C. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) modeling, used to evaluate the data for all compound groups, suggest that during flue gas quenching at temperatures of 400 °C low-chlorinated homologues are preferentially formed in the presence of copper, which is known to be a very active catalyst for this process. At 300 and 200 °C, the formation of highly-chlorinated homologues is favored.

  14. A toxic equivalency factor scale for polychlorinated dibenzofurans

    USGS Publications Warehouse

    Tysklind, M.; Tillitt, D.; Eriksson, L.; Lundgren, K.; Rappe, C.

    1994-01-01

    The ethoxyresorufin O-deethylase (EROD) induction of 20 polychiorinated dibenzofurans (PCDFs) was examined in the H4IIE rat hepatoma cell bioassay. The selection of the compounds tested was based on a multivariate chemical characterization laying the groundwork for covering the whole chemical series of PCDFs. The EROD induction potency was found to vary in ED50 values from 25 to 100,000,000 pg/mg, i.e., nearly seven orders of magnitude. The response of the bioassay was calibrated against the 2,3,7,8-tetrachlorodibenzo-p-dioxin, enabling the corresponding toxic equivalency factors (TEFs) to be calculated. In order to establish a quantitative structure-activity relationship (QSAR) for the TEF values, 37 physicochemical descriptor variables were used to chemically characterize the 87 tetra- to octachlorinated PCDFs. Using partial least-squares modeling on a training set of 10 congeners, a QSAR model with sound predictive power was obtained. The QSAR model was validated with a validation set of additional 10 congeners. The predicted TEFs indicate that a large number of congeners are potent EROD inducers.

  15. Serum dioxin levels in Vietnamese men more than 40 years after herbicide spraying.

    PubMed

    Manh, Ho Dung; Kido, Teruhiko; Okamoto, Rie; Xianliang, Sun; Anh, Le Thai; Supratman, Supratman; Maruzeni, Shoko; Nishijo, Muneko; Nakagawa, Hideaki; Honma, Seijiro; Nakano, Takeshi; Takasuga, Takumi; Nhu, Dang Duc; Hung, Nguyen Ngoc; Son, Le Ke

    2014-03-18

    Recent studies have found elevated dioxin levels inside some U.S. military former air bases in Vietnam, known as hotspots. Many studies of Agent Orange have been done in U.S. veterans; however, there is little known about Vietnamese men. In 2010, we collected blood samples from 97 men in a hotspot and 85 men in an unsprayed area in Northern Vietnam. Serum concentrations of not only TCDD but also other dioxins (PCDDs), furans (PCDFs), and nonortho polychlorinated biphenyls (PCBs) were significantly higher in the hotspot than in the unsprayed area. In the hotspot, three subareas were demarcated, based on their proximity to the air base. The total toxic equivalents (TEQ) of PCDDs/PCDFs+PCBs was 41.7 pg/g lipid in the area closest to the air base, while it was around 29 pg/g lipid in the other two subareas. In the unsprayed area, the dioxin levels were no different between men who went to the South during the Vietnam War and those who remained in the North, with TEQs PCDDs/PCDFs+PCBs of around 13.6 pg/g lipid. Our findings suggested that people living close to the former U.S. air bases might have been exposed to both Agent Orange and other sources of dioxin-like compounds. PMID:24552243

  16. Declining Dioxin concentrations in the Rhone River, France, attest to the effectiveness of emissions controls

    USGS Publications Warehouse

    Van Metre, Peter C.; Babut, Marc; Mourier, Brice; Mahler, Barbara J.; Roux, Gwenaelle; Desmet, Marc

    2015-01-01

    Emission-control policies have been implemented in Europe and North America since the 1990s for polychlorodibenzodioxins (PCDDs) and furans (PCDFs). To assess the effect of these policies on temporal trends and spatial patterns for these compounds in a large European river system, sediment cores were collected in seven depositional areas along the Rhone River in France, dated, and analyzed for PCDDs and PCDFs. Results show concentrations increase in the downstream direction and have decreased temporally at all sites during the last two decades, with an average decrease of 83% from 1992 to 2010. The time for a 50% decrease in concentrations (t1/2) averaged 6.9 ± 2.6 and 9.1 ± 2.9 years for the sum of measured PCDDs and PCDFs, respectively. Congener patterns are similar among cores and indicate dominance of regional atmospheric deposition and possibly weathered local sources. Local sources are clearly indicated at the most downstream site, where concentrations of the most toxic dioxin, TCDD, are about 2 orders of magnitude higher than at the other six sites. The relatively steep downward trends attest to the effects of the dioxin emissions reduction policy in Europe and suggest that risks posed to aquatic life in the Rhone River basin from dioxins and furans have been greatly reduced.

  17. Effects of regional differences in waste composition on the thermal formation of polychlorinated aromatics during incineration.

    PubMed

    Phan, Duong Ngoc Chau; Jansson, Stina; Marklund, Stellan

    2013-11-01

    Two artificial wastes (A and B) whose contents reflect regional differences in municipal solid waste composition, were used to investigate the thermal formation of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and naphthalenes (PCNs) during incineration. Flue gas samples were simultaneously collected at three ports in the post-combustion zone corresponding to flue gas temperatures of 400, 300, and 200 °C. The combustion of Waste B, which had a higher chlorine and metal content than Waste A, produced greater levels of highly-chlorinated homologues, as demonstrated by a higher degree of chlorination. The total concentrations of PCDDs, PCDFs, PCBs, and PCNs formed in the combustion of both wastes increased as temperature decreased along the convector. There were no significant differences in total concentrations between Waste A and Waste B combustion at specific temperatures, with exception of PCDFs at 400 °C. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) modeling, used to evaluate the data for all compound groups, suggest that during flue gas quenching at temperatures of 400 °C low-chlorinated homologues are preferentially formed in the presence of copper, which is known to be a very active catalyst for this process. At 300 and 200 °C, the formation of highly-chlorinated homologues is favored. PMID:24007615

  18. Evaluation of planar halogenated and polycyclic aromatic hydrocarbons in estuarine sediments using ethoxyresorufin-O-deethylase induction of H4IIE cells

    SciTech Connect

    Gale, R.W.; Long, E.R.; Schwartz, T.R.; Tillitt, D.E.

    2000-05-01

    Polycyclic aromatic hydrocarbons (PAHs) and planar halogenated hydrocarbons (PHHs), including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) were determined in fractionated sediment extracts from the Hudson-Raritan estuary and Newark Bay, New Jersey, USA, as part of a comprehensive risk assessment. Contributions of PCDDs/PCDFs, PCBs, and PAHs to the total toxic equivalents (TEQs) were measured using an H4IIE bioassay that calculated from instrumentally determined concentrations using international toxic equivalency factors. The H4IIE TEQs of whole and fractionated extracts were compared to calculated TEQs to investigate the applicability of the bioassay approach for evaluating 7-ethoxyresorufin-O-deethylease induction by PHHs and PAHs present together in complex mixtures. Although 2,3,7,8-tetrachlorodibenzo-p-dioxin contributed from 41 to 79% of the calculated TEQs from PCDDs/PCDFs and planar PCBs in all sediments sampled, the PAH-containing fractions accounted for >80% of the total TEQs determined either instrumentally or by bioassay. Calculated TEQs from PAHs, based on reported toxic equivalency factors for only seven PAHs, were severalfold greater than the bioassay-derived TEQs of PAH-only fractions of the sediment extracts. Significant correlations were observed between bioassay and instrumentally determined toxic equivalents in the more purified fractions but not in fractions only purified by size-exclusion or argentate chromatographies alone.

  19. Bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran and extractable organic chlorine at a bleached-kraft mill site in a northern Canadian river system

    SciTech Connect

    Owens, J.W. ); Swanson, S.M. ); Birkholz, D.A. )

    1994-02-01

    Abiotic and biotic environmental compartments in a northern Canadian river system have been analyzed for poly-chlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and extractable organochlorines (EOCl) down-stream of a bleached-kraft mill. The water column, deposited and suspended sediments, invertebrates, and tissues from several fish species were analyzed. The data indicate that (a) conversion of the mill bleaching process to 100% chlorine dioxide virtually eliminated the discharge of PCDDs and PCDFs; (b) PCDD, PCDF, and EOCl transport occurred primarily in suspended sediments; and (c) the food choice of filter-feeding insects by specific fish species such as the mountain whitefish (Prosopium williamsoni) was an important determinant in the food-chain transfer of the principal compounds, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8-tetrachlorodibenzofuran (TCDF). Relative to mountain whitefish, TCDD and TCDF levels in another bottom feeding species, longnose sucker (Catostomus catostomus), were at least an order of magnitude lower. Food-chain biomagnification of TCDD and TCDF was not observed in omnivorous and predatory species, burbot (Lota lota) and walleye (Stizostedium vitreum), for which lipid-adjusted levels were similar to those in the longnose sucker. These data indicate that organism lipid levels alone are not sufficient to predict species-specific bioaccumulation of these hydrophobic compounds, and that site-specific transport and species food choice parameters should be included in bioaccumulation models for hydrophobic compounds such as PCDDs and PCDFs.

  20. Occurrence of polybrominated diphenylethers, polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in coastal sediments from Spain.

    PubMed

    Eljarrat, Ethel; De La Cal, Agustina; Larrazabal, David; Fabrellas, Begoña; Fernandez-Alba, Amadeo Rodriguez; Borrull, Francesc; Marce, Rosa Maria; Barcelo, Damia

    2005-08-01

    Fifteen sediment samples were analysed in order to determine their content of polybrominated diphenylethers (PBDEs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). Samples were collected from several hot spots on the Spanish coast, such as the harbours of Almeria and Tarragona, and the mouths of the Besos and Llobregat rivers in Barcelona. A generic analytical procedure based on Soxhlet extraction followed by an automated cleanup system and gas chromatography-ion trap-mass spectrometry was employed for determining the toxic congeners of PCDDs and PCDFs, as well as dioxin-like PCBs. As regards PBDE determinations, a rapid method based on the use of selective pressurized liquid extraction followed by gas chromatography-negative ion chemical ionization-mass spectrometry was applied. Total toxicity equivalent (WHO-TEQ) values were calculated using the toxicity equivalent factors proposed by WHO for dioxin-like PCBs, PCDDs and PCDFs. WHO-TEQ values ranged from 0.3 to 75 pg/g dry weight (dw), with PCB contribution on the toxicity of the samples between 1 and 84%. Total PBDE levels ranged from 2.7 to 134 ng/g dw, with BDE-209 contribution on the total PBDE contamination between 50 and 99%.

  1. Human body burden of polychlorinated dibenzofurans associated with toxicity based on the yusho and yucheng incidents

    SciTech Connect

    Ryan, J.J.; Gasiewicz, T.A.; Brown, J.F. Jr. )

    1990-11-01

    The polychlorinated dibenzofurans (PCDFs) are one group of man-made toxicants for which reasonably extensive data exist relevant to dose-response relationships in humans. Examination of contaminated food oil consumption from the yusho (Japan) poisoning incident indicates the mean uptake or body burden of 2, 3, 4, 7, 8-pentachlorodibenzofuran (PnCDF) equivalents (PEQ) associated with nausea and anorexia to be 4.4 micrograms/kg body wt and that associated with chloracne to be 5.9 micrograms/kg. For the yucheng (Taiwan) poisoning incident, blood measurements for chloracne show a similar body burden of 4.0 micrograms/kg. The latter value is toxicologically equivalent to a 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent (TEQ) body burden of 2.0 micrograms/kg body wt or about 150 micrograms for an adult person. This corresponds to an adipose tissue level of about 10 micrograms/kg fat, and is comparable to that known to cause chloracne in rhesus monkeys. These body burdens on a TEQ basis are more than 200 times higher than the average current levels of PCDDs/PCDFs found in North American populations and are the first to relate human body burdens of PCDFs with a known effect and to compare them to animal data. Since the effects reported may not be the most sensitive indicator of human toxicity, lower body burdens could be associated with more subtle toxicological events.

  2. A cross-sectional analysis of dioxins and health effects in municipal and private waste incinerator workers in Japan.

    PubMed

    Yamamoto, Kenya; Kudo, Mitsuhiro; Arito, Heihachiro; Ogawa, Yasutaka; Takata, Tsutomu

    2015-01-01

    This cross-sectional study was intended to examine health effects of 678 male workers employed during an 8-yr period from 2000 to 2007 at 36 municipal and private waste incineration plants in Japan. Blood samples were obtained for analysis of concentrations of dioxins including coplanar polychlorinated biphenyls (coplanar PCBs) and evaluation of health effects. Health effects including diabetes were surveyed via a physician's interview or clinical data from blood samples. There was a certain difference in serum concentrations of polychlorinated dibenzofurans (PCDFs) between the incinerator workers and Japanese general population, although no differences in the concentrations of total dioxins or polychlorinated dibenzo-p-dioxins (PCDDs) were found between the two groups. A few positive correlations between serum levels of PCDDs and PCDFs and the results of laboratory and physiological tests were found, but coplanar PCBs showed significant relations with 14 parameters of the tests. The background serum levels of PCDDs, PCDFs and total dioxins were significantly associated with the prevalence of diabetes. No essential differences in serum concentrations of total dioxins and in prevalence of diabetes between our subjects and the general population suggested that the incinerator workers were marginally exposed to dioxins in the workplace without any recognizable adverse health effects. PMID:26212412

  3. Dioxinlike components in incinerator fly ash: a comparison between chemical analysis data and results from a cell culture bioassay.

    PubMed Central

    Till, M; Behnisch, P; Hagenmaier, H; Bock, K W; Schrenk, D

    1997-01-01

    Potent polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxinlike polychlorinated biphenyls (PCBs) are among the most relevant toxic emissions from incinerators. Induction of cytochrome P450 1A1-catalyzed 7-ethoxyresorufin O-deethylase (EROD) activity in mammalian cell culture (EROD bioassay) is thought to be a selective and sensitive parameter used for the quantification of dioxinlike compounds. Fly ash extracts from municipal waste incinerators (MWI), a crematorium, wood combustors, and a noble metal recycling facility were analyzed in the EROD bioassay using rat hepatocytes in primary culture. Fractions containing 2,3,7,8-substituted PCDDs/PCDFs, dioxinlike PCBs, and 16 major polycyclic aromatic hydrocarbons (PAHs) were isolated from the extract and analyzed by gas chromatography-mass spectrometry (GC-MS) and by the EROD bioassay. It was found that with MWI samples the bioassay of the extract resulted in a two- to fivefold higher estimate of TCDD equivalents (TEQ) than the chemical analysis of PCDDs/PCDFs and PCBs. However, the outcome of both methods was significantly correlated, making the bioassay useful as a rough estimate for the sum of potent PCDDs/PCDFs and dioxinlike PCBs in extracts from MWI fly ash samples and in a fly ash sample from a crematorium. In noble metal recycling facility and wood combustor samples, higher amounts of PAHs were found, contributing to more pronounced differences between the results of both methods. The remaining unexplained inducing potency in fly ash samples probably results from additional dioxinlike components including certain PAHs not analyzed in this study.The hypothesis that emissions from MWI of hitherto unidentified dioxinlike compounds are higher by orders of magnitude than emissions of potent PCDDs/PCDFs and dioxinlike PCBs could not be confirmed. We found no indication for a marked synergistic interaction of dioxinlike fly ash components in the bioassay. Images Figure 1. Figure

  4. Dioxin-like toxicity in the Saginaw River Watershed: polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in sediments and floodplain soils from the Saginaw and Shiawassee Rivers and Saginaw Bay, Michigan, USA.

    PubMed

    Kannan, Kurunthachalam; Yun, Se Hun; Ostaszewski, Arthur; McCabe, John M; Mackenzie-Taylor, Deborah; Taylor, Allan B

    2008-01-01

    Sediment and floodplain soils in the Saginaw River Watershed, Michigan, USA, have been demonstrated to be contaminated with a variety of organic compounds, including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). Existing data indicate that, at some locations, the contamination exceeds human health risk-based regulatory levels and ecological risk-based screening levels. In this study, concentrations of PCBs including non-ortho coplanar congeners, PCDDs, and PCDFs were measured in more than 120 sediment and floodplain soil samples collected from the Shiawassee River (a tributary of the Saginaw River), the Saginaw River, and Saginaw Bay, to determine the sources and magnitude of contamination, and to elucidate the contributions from individual contaminant groups to the overall 2,3,7,8-tetrachlorodibezo-p-dioxin equivalents (TEQs). Sediment and soil extracts were also analyzed for total dioxin-like activity by means of the H4IIE-luc cell bioassay. Elevated concentrations of PCBs (>1000 ng/g, dry weight) were found in surface sediment and floodplain soil samples collected from the Shiawassee River near Chase Lake, from Middleground Island in the Saginaw River, and from subsurface sediments in Saginaw Bay. Concentrations of PCDDs and PCDFs in sediment and floodplain soils from the Saginaw River and Saginaw Bay were 2 to 3 orders of magnitude higher than concentrations in the samples from the Shiawassee River. The highest PCDD/F concentration (55,200 pg/g, dry weight in a subsurface layer) was found in sediment collected at the mouth of the Saginaw River. Concentrations of PCDFs were greater than the concentrations of PCDDs in sediment from the Saginaw River. 2,3,7,8-TCDF, 1,2,3,7,8-PeCDF, and 2,3,4,7,8-PeCDF were the major PCDF congeners found in sediments from the Saginaw River. The elevated concentrations of PCDFs, and the predominance of the less highly chlorinated PCDF congeners, in sediments

  5. "Pig in a poke (gato por liebre)": the "mota" (Calophysus macropterus) fishery, molecular evidence of commercialization in Colombia and toxicological analyses.

    PubMed

    Salinas, Cristian; Cubillos, Juan Camilo; Gómez, Rigoberto; Trujillo, Fernando; Caballero, Susana

    2014-06-01

    Overfishing has affected the population abundance trends of many commercial fish species. In the Amazon, the fishery of a catfish commonly known as "mota" or "piracatinga" (Calophysus macropterus) has become an important economic activity in the region as this species has replaced a number of other overexploited great catfish species in the markets. Due to this high exploitation, ways in which to increase captures have been identified. One strategy is to use decomposing animal carcasses as bait. Such strategy has increased the hunting pressure on endangered species such as caimans and river dolphins. We investigated which catfish species are currently commercialized in Colombian fish markets using DNA barcoding, and measured mercury concentration in the tissues of fish molecularly identified as C. macropterus. We collected 86 fish samples in markets of four Colombian cities. Sixty-eight of these were identified molecularly as C.macropterus. The mercury concentration of 29 such samples was analyzed. Samples presented total Hg concentrations higher than the limit for human consumption established by the WHO (0.5 μg/g). These results are worrisome and suggest that (1) C. macropterus is a widely used fish species for human consumption in Colombia and (2) C. macropterus has high concentrations of total Hg, making its consumption a public health risk. Results presented here suggest that C. macropterus has replaced capaz in most Colombian markets. This fishery threatens wild species of river dolphins and caimans, and is also a public health risk given the high mercury levels we found in a subsample of these fishes. PMID:24419666

  6. Comparacion de Modelos de Educacion Sexual en El Conocimiento y Cambio de Actitudes en Practicas Sexuales por Alumnos de Nivel Superior en La Region De Caguas, Puerto Rico

    ERIC Educational Resources Information Center

    Juan, Vallejo Ramos L.

    2012-01-01

    In opposition to the Sexual Education Traditional Model (SETM) that is used in the state schools of Puerto Rico, the Health Beliefs Model (HBM) appears. It facilitates a curricular design that improves the ability of the students to respond to the group pressure by means of attitudes that stimulate sexual conducts of smaller risk of propagation of…

  7. Realidades Suburbanas: Latinos en el Condado de Dakota. Una Investigacion Dirigida por HACER = Suburban Realities: Latinos in Dakota County. A Study Conducted by HACER.

    ERIC Educational Resources Information Center

    HACER: Hispanic Advocacy and Community Empowerment through Research, Minneapolis, MN.

    A research project was conducted between April and December of 1998 to learn about the experiences of the sizable numbers of Latinos who live in Dakota County (Minnesota). This diverse group was studied through examining existing demographic information, conducting interviews with 45 Latino and Anglo individuals, and conducting several focus…

  8. Vientos impulsados por radiación en supergigantes B en rotación: análisis de los regímenes de soluciones

    NASA Astrophysics Data System (ADS)

    Venero, R. O. J.; Curé, M.; Cidale, L.

    2016-08-01

    The theory of radiation driven winds for rotating early-type stars gives three classes of hydrodynamic solutions. These are: the classical m-CAK solution or fast solution, the solution for fast rotators, and the solution for special ionization conditions along the wind structure. In this work we study the domains of every kind of solution in the and parameter space, where is the equatorial rotation speed in terms of the critical rotation velocity, and is the radiation force parameter that determines the ionization structure of the wind. This analysis is performed for different values of effective temperature corresponding to the spectral subtypes among B supergiants. We propose that the winds of B-type supergiants could change between the different velocity regimes, if small variations in the plasma ionization conditions take place. These variations could happen between two consecutive evolutionary stages of B supergiants or, in a short term, explaining the variability observed in the spectra of these stars.

  9. Comienza la construcción de instalación patrocinada por el NCI en Puerto Rico para realizar estudios

    Cancer.gov

    El gobierno de Puerto Rico ha destinado $196 millones de dólares para construir un hospital oncológico de 287 000 pies cuadrados en San Juan, que contará con 96 camas. El nuevo hospital es el primero en su clase en la región caribeña y en él se llevarán a

  10. Adolescentes que no habrían fumado pueden ser atraídos por los cigarrillos electrónicos

    Cancer.gov

    Artículo del blog Temas y relatos sobre un estudio reciente que sugiere que los adolescentes están usando cigarrillos electrónicos no solo como sustituto de cigarrillos convencionales sino cigarrillos electrónicos están atrayendo nuevos usuarios de tabaco

  11. The HoMBReS and HoMBReS Por un Cambio Interventions to Reduce HIV Disparities Among Immigrant Hispanic/Latino Men.

    PubMed

    Rhodes, Scott D; Leichliter, Jami S; Sun, Christina J; Bloom, Fred R

    2016-02-12

    Hispanics/Latinos in the United States are affected disproportionately by human immunodeficiency virus (HIV) infection, acquired immunodeficiency syndrome (AIDS), and other sexually transmitted diseases (STDs); however, few effective evidence-based prevention interventions for this population exist. This report describes the Hombres Manteniendo Bienestar y Relaciones Saludables (Men Maintaining Wellbeing and Healthy Relationships) (HoMBReS) intervention, which was developed by a community-based, participatory research partnership in North Carolina and initially implemented during 2005-2009. HoMBReS is an example of an effective intervention that uses lay health advisors (known as Navegantes [navigators]) in the context of existing social networks (i.e., recreational soccer teams) to promote consistent condom use and HIV and STD testing among Hispanic/Latino men. In 2012, HoMBReS was classified as a best-evidence community-level HIV prevention intervention (CDC. Compendium of evidence-based behavioral interventions and best practices for HIV prevention. Atlanta, GA: US Department of Health and Human Services, CDC; 2015). The intervention has been implemented elsewhere, enhanced, and further evaluated in longitudinal intervention and implementation studies. HoMBReS has been adapted for other populations, including men who have sex with men and transgender persons. Additional evaluation has found that Navegantes continue in their roles as health advisors, opinion leaders, and community advocates after study support ends. Hispanic/Latino men's social networks can be leveraged to promote sexual health within the community by decreasing HIV risk behaviors among Hispanics/Latinos in the United States.

  12. "Pig in a poke (gato por liebre)": the "mota" (Calophysus macropterus) fishery, molecular evidence of commercialization in Colombia and toxicological analyses.

    PubMed

    Salinas, Cristian; Cubillos, Juan Camilo; Gómez, Rigoberto; Trujillo, Fernando; Caballero, Susana

    2014-06-01

    Overfishing has affected the population abundance trends of many commercial fish species. In the Amazon, the fishery of a catfish commonly known as "mota" or "piracatinga" (Calophysus macropterus) has become an important economic activity in the region as this species has replaced a number of other overexploited great catfish species in the markets. Due to this high exploitation, ways in which to increase captures have been identified. One strategy is to use decomposing animal carcasses as bait. Such strategy has increased the hunting pressure on endangered species such as caimans and river dolphins. We investigated which catfish species are currently commercialized in Colombian fish markets using DNA barcoding, and measured mercury concentration in the tissues of fish molecularly identified as C. macropterus. We collected 86 fish samples in markets of four Colombian cities. Sixty-eight of these were identified molecularly as C.macropterus. The mercury concentration of 29 such samples was analyzed. Samples presented total Hg concentrations higher than the limit for human consumption established by the WHO (0.5 μg/g). These results are worrisome and suggest that (1) C. macropterus is a widely used fish species for human consumption in Colombia and (2) C. macropterus has high concentrations of total Hg, making its consumption a public health risk. Results presented here suggest that C. macropterus has replaced capaz in most Colombian markets. This fishery threatens wild species of river dolphins and caimans, and is also a public health risk given the high mercury levels we found in a subsample of these fishes.

  13. Efectos de Campos Magnéticos en las Tasas de Consumo de Madera por Coptotermes formosanus, la Termita Subterránea de Formosa.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sixty groups of 500 workers and 50 soldiers of Coptotermes formosanus were maintained in costume designed containers and fed with a piece of red oak wood (Quercus rubra). Twenty of these groups were exposed to permanent magnets with a flux of 800 G. Another 20 groups were exposed to a permanent mag...

  14. Communicating with Mexican Americans: Por Su Buena Salud = Communicando Con Mexico Americanos: For Their Good Health. Proceedings of the Conference (Houston, TX, September 13-14, 1979).

    ERIC Educational Resources Information Center

    Moore, Thomas J., Ed.; And Others

    The conference focused on the role of the Mexican American's cultural language, tradition, life style, health practices, and media utilization in the design of effective health education and information programs. Representing various local, state, and national health, education, and media organizations, the 108 participants attended sessions on…

  15. Beneficios y riesgos de la terapia estrogénica en la menopausia varían por edad, de acuerdo con el e

    Cancer.gov

    Los datos de seguimiento a largo plazo del estudio Iniciativa para la Salud de la Mujer (WHI) proporcionan información nueva e importante sobre los posibles riesgos y beneficios de la terapia hormonal para tratar síntomas relacionadas con la menopausia.

  16. Unanswered Questions in Colombia's Foreign Language Education Policy (Preguntas por responder en la política educativa de lenguas extranjeras en Colombia)

    ERIC Educational Resources Information Center

    Bonilla Carvajal, Camilo Andrés; Tejada-Sánchez, Isabel

    2016-01-01

    Following the trend of much of the Western, non-English speaking world, Colombia has tirelessly strived for spreading English education in an effort to augment economic benefits. This paper aims at providing a critical account of foreign language education policy in Colombia, with special attention to English. It outlines the impact of its…

  17. Comparacion de modelos de Educacion Sexual en el conocimiento y cambio de actitudes en practicas sexuales por alumnos de nivel superior en la region de Caguas, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Juan, Vallejo Ramos L.

    In opposition to the Sexual Education Traditional Model (SETM) that is used in the state schools of Puerto Rico, the Health Beliefs Model (HBM) appears. It facilitates a curricular design that improves the ability of the students to respond to the group pressure by means of attitudes that stimulate sexual conducts of smaller risk of propagation of the Sexually Transmitted Diseases (STD). In addition, it provides activities to increase the self-esteem, the communication and the decision making. This investigation had the intention to compare the SETM and the HBM in the increase of knowledge and change of attitudes of high risk of propagation of the STD using a validated questionnaire (Agency of the United States for the International-USAID Development), named "Endesa 2007" and, adapted to Puerto Rico by the Dra.Marta Collazo to a sample of students between the 17 and 19 years of 2 state schools of San Lorenzo, as a pretest, and, selected by convenience. Then, a 10 hours training was administered to half of the students using the SETM to STD and condom use lessons. The other half of the students received additional lessons using the HBM. Finally, both groups took the questionnaire again as a posttest. The sample of students, in average, did not reach the knowledge and basic levels of attitudes towards the STD in the pretest. This reflected 2 possible implications on the SETM. In first place, that the way in which the STD is implemented as part of the Sexual Education curriculum is inefficient. Secondly, the possibility that the acquired information or attitudes does not have permanence. Culminated the questionnaire, the HBM increase the knowledge of the STD in 0.41 points (average) over the SETM. There was not a significant difference between both models, in attitudes, implying that both models are equally effective. The findings suggests that the HBM is more effective increasing the knowledge on the STD, but equally effective than the SETM in attitude change for the Puerto Rican youth.

  18. Ameiridae Boeck and Argestidae Por revisited, with establishment of Parameiropsidae, a new family of Harpacticoida (Crustacea, Copepoda) from deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Corgosinho, P. H. C.; Martínez Arbizu, P.

    2010-09-01

    Four new species of Parameiropsis are described from Angola and Guinea Basins and the Arctic Laptev Sea. The male of Parameiropsis poseidonicus sp. n. differs from that of P. neptuni sp. n. and P. senckenbergi sp. n. in antennule segmentation, length of the proximal aesthetasc, length of the outermost seta of the antennary endopod, degree of reduction of the mouthparts, relative length of the inner spine of the basis of thoracopod 1, shape of the furca and body length. The female of P. amphitriteae sp. n. differs from previously described females of other species in the smaller exopod and endpod of thoracopod 1, reduced armature of thoracopods 1-6, length of the outer setae of exopods and endopods of thoracopods 2-4, and mandible exopod weakly developed and fused to the basis. Parameiropsis is redefined by the following autapomorphies: presence of aesthetasc on 3rd segment of female antennule; antenna strong, with endopod curved upwardly, and shape of the outermost (strongly ornamented) spine; triangular labrum; elongated corpus mandibularis, gnathobasis very long; basis of mandibular palp unarmed; elongated maxillule, with long and flexible setae on praecoxal arthrite; basis of the maxilla with strongly modified claw. To discuss the phylogenetic position of Parameiropsis, we revaluated the subfamilies of Ameiridae (viz. Ameirinae and Stenocopiinae) and the family Argestidae. Anoplosomella and Malacopsyllus revealed to be not closely related to Ameiridae and are transferred to Argestidae, sharing with other members of this family the morphology of the mandible gnathobasis, armature of maxilla and armature and length of the first segment of the antennule. Argestoides prehensilis does not show any of the characters that we consider autapomorphic for Argestidae. Instead, it shows many characters in common with several Ameiridae species. Parameiropsis does not have any character that could justify its inclusion within Ameiridae or even within Podogennonta. It also cannot be included satisfactorily within Argestidae nor Exanechentera. Therefore, we here propose a new family for Parameiropsis, with unclear relationships within Harpacticoida. After these taxonomic rearrangements, Ameiridae and Argestidae are considered monophyletic based on certain maxilla characters that we consider autapomorphic for each group. A key to the identification of the known species of Parameiropsis is added at the end.

  19. The HoMBReS and HoMBReS Por un Cambio Interventions to Reduce HIV Disparities Among Immigrant Hispanic/Latino Men.

    PubMed

    Rhodes, Scott D; Leichliter, Jami S; Sun, Christina J; Bloom, Fred R

    2016-02-12

    Hispanics/Latinos in the United States are affected disproportionately by human immunodeficiency virus (HIV) infection, acquired immunodeficiency syndrome (AIDS), and other sexually transmitted diseases (STDs); however, few effective evidence-based prevention interventions for this population exist. This report describes the Hombres Manteniendo Bienestar y Relaciones Saludables (Men Maintaining Wellbeing and Healthy Relationships) (HoMBReS) intervention, which was developed by a community-based, participatory research partnership in North Carolina and initially implemented during 2005-2009. HoMBReS is an example of an effective intervention that uses lay health advisors (known as Navegantes [navigators]) in the context of existing social networks (i.e., recreational soccer teams) to promote consistent condom use and HIV and STD testing among Hispanic/Latino men. In 2012, HoMBReS was classified as a best-evidence community-level HIV prevention intervention (CDC. Compendium of evidence-based behavioral interventions and best practices for HIV prevention. Atlanta, GA: US Department of Health and Human Services, CDC; 2015). The intervention has been implemented elsewhere, enhanced, and further evaluated in longitudinal intervention and implementation studies. HoMBReS has been adapted for other populations, including men who have sex with men and transgender persons. Additional evaluation has found that Navegantes continue in their roles as health advisors, opinion leaders, and community advocates after study support ends. Hispanic/Latino men's social networks can be leveraged to promote sexual health within the community by decreasing HIV risk behaviors among Hispanics/Latinos in the United States. PMID:26916740

  20. The effects of the porous buffer layer and doping with dysprosium on internal stresses in the GaInP:Dy/por-GaAs/GaAs(100) heterostructures

    SciTech Connect

    Seredin, P. V.; Gordienko, N. N.; Glotov, A. V.; Zhurbina, I. A.; Domashevskaya, E. P.; Arsent'ev, I. N. Shishkov, M. V.

    2009-08-15

    In structures with a porous buffer layer, residual internal stresses caused by a mismatch between the crystal-lattice parameters of the epitaxial GaInP alloy and the GaAs substrate are redistributed to the porous layer that acts as a buffer and is conducive to disappearance of internal stresses. Doping of the epitaxial layer with dysprosium exerts a similar effect on the internal stresses in the film-substrate structure.

  1. "¿Por qué leemos esto en la clase de español?": The Politics of Teaching Literature in Spanglish

    ERIC Educational Resources Information Center

    Postma, Regan L.

    2013-01-01

    This article discusses what is at stake in teaching works written in "Spanglish" in Spanish departments and what teaching such works might mean for students and the scholarly community at large. This article primarily comes out of the author's experiences teaching "Spanglish" works in Spanish courses at a major research…

  2. Library Safari: Tips for Parents of Young Readers and Explorers = De safari por la biblioteca: Consejos para padres de lectores y exploradores jovenes.

    ERIC Educational Resources Information Center

    Clements, Aedin

    Visiting the library is a great way for parents to encourage their child's imagination and learning. It gives parents the opportunity to model good reading behavior and to show their child that they value books and reading. No matter how young the child is, a trip to the library can be an enjoyable outing for parents and their children. Most…

  3. Effects of combustion and operating conditions on PCDD/PCDF emissions from power boilers burning salt-laden wood waste.

    PubMed

    Leclerc, Denys; Duo, Wen Li; Vessey, Michelle

    2006-04-01

    This paper discusses the effects of combustion conditions on PCDD/PCDF emissions from pulp and paper power boilers burning salt-laden wood waste. We found no correlation between PCDD/PCDF emissions and carbon monoxide emissions. A good correlation was, however, observed between PCDD/PCDF emissions and the concentration of stack polynuclear aromatic hydrocarbons (PAHs) in the absence of TDF addition. Thus, poor combustion conditions responsible for the formation of products of incomplete combustion (PICs), such as PAHs and PCDD/PCDF precursors, increase PCDD/PCDF emissions. PAH concentrations increased with higher boiler load and/or low oxygen concentrations at the boiler exit, probably because of lower available residence times and insufficient excess air. Our findings are consistent with the current understanding that high ash carbon content generally favours heterogeneous reactions leading to either de novo synthesis of PCDD/PCDFs or their direct formation from precursors. We also found that, in grate-fired boilers, a linear increase in the grate/lower furnace temperature produces an exponential decrease in PCDD/PCDF emissions. Although the extent of this effect appears to be mill-specific, particularly at low temperatures, the results indicate that increasing the combustion temperature may decrease PCDD/PCDF emissions. It must be noted, however, that there are other variables, such as elevated ESP and stack temperatures, a high hog salt content, the presence of large amounts of PICs and a high Cl/S ratio, which contribute to higher PCDD/PCDFs emissions. Therefore, higher combustion temperatures, by themselves, will not necessarily result in low PCDD/PCDFs emissions.

  4. Dioxin-like PCBs and PCDD/Fs in surface sediments near the shore of Winam Gulf, Lake Victoria.

    PubMed

    Omwoma, Solomon; Lalah, Joseph O; Virani, Munir; Schramm, Karl-Werner; Henkelmann, Bernhard

    2015-01-01

    Winam Gulf of Lake Victoria is considered to be contaminated with toxic chemicals emanating from anthropogenic activities, especially near large industrial towns such as Kisumu. This has recently caused concerns about its water quality and impact on aquatic organisms and human beings. This study was justified by the need to generate baseline concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in surface sediment from selected sites in the lake and determine the influence of activities on their concentrations and potential risks to fish-eating birds living near the lake. Surface sediments (<30cm) from three different fish landing beaches, located 200m from the shore of Winam Gulf of Lake Victoria near Kisumu city, Homa Bay and Mbita (control) towns, were analysed. The total mean concentrations (in pgg(-1)drywt) were found to range from 17.4-812 (Σdl-PCBs), 36.6-813 (ΣPCDDs) and 1.45-46.4 (ΣPCDFs). The calculated Toxic Equivalents (TEQWHO(2005)) ranged from 0.001-0.43 (Σdl-PCBs) and 0.09-31 (ΣPCDD/Fs). The fish landing beaches at Kisumu city were found to be contaminated with respect to dl-PCBs and dioxins, followed by Homa Bay and Mbita. The relatively high levels of octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) influenced the TEQ and the ΣPCDFs/ΣPCDDs ratios indicated chemical processes as partial sources of the dioxins. The levels of contaminants obtained in this study showed potential exposure to aquatic organisms and fish eating birds through food chain transfer. PMID:25150826

  5. Evaluation of a sampling and analysis method for determination of polyhalogenated dibenzo-p-dioxins and dibenzofurans in ambient air

    SciTech Connect

    Harless, R.L.; Lewis, R.G.; McDaniel, D.D.; Gibson, J.F.; Dupuy, A.E.

    1991-01-01

    General Metals Works PS-1 PUF air samplers and an analytical method based on high resolution gas chromatography - high resolution mass spectrometry (HRGC-HRMS) were evaluated for determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDDs/PBDFs) and bromo/chloro dibenzo-p-dioxins and dibenzofurans (BCDDs/BCDFs) in ambient air. Dilute solutions of these compounds and (13)C12-1,2,3,4-TCDD were used to spike the filters of PS-1 air samplers which were then operated 24 hrs to sample 350-400 cu m ambient air. After sampling, each quartz-fiber filter and polyurethane foam (PUF) were spiked with (13)C12-labeled PCDD, PCDF, PBDD, and PBDF internal standards before separate Soxhlet extractions with benzene. The extracts were subjected to an acid/base clean-up procedure followed by clean-up on microcolumns of silica gel, alumina, and carbon and then analyzed by HRGC-HRMS. Results derived from the study indicated the PS-1 ambient air samplers and the analytical procedures were very efficient and that pg/cu m and sub-pg/cu m levels of total PCDDs/PCDFs, PBDDs/PBDFs, BCDDs/BCDFs, and 2,3,7,8-substituted congeners could be accurately measured. Background levels of these compounds in the ambient air were also determined. Total PCDDs, PCDFs, TBDFs, and PeBDFs were detected in a low concentration range of 0.3 to 3.0 pg/cu m.

  6. Waste disposal technologies for polychlorinated biphenyls.

    PubMed Central

    Piver, W T; Lindstrom, F T

    1985-01-01

    Improper practices in the disposal of polychlorinated biphenyl (PCB) wastes by land burial, chemical means and incineration distribute these chemicals and related compounds such as polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzodioxins (PCDDs) throughout the environment. The complete range of methods for disposal that have been proposed and are in use are examined and analyzed, with emphasis given to the two most commonly used methods: land burial and incineration. The understanding of aquifer contamination caused by migration of PCBs from subsurface burial sites requires a description of the physical, chemical and biological processes governing transport in unsaturated and saturated soils. For this purpose, a model is developed and solved for different soil conditions and external driving functions. The model couples together the fundamental transport phenomena for heat, mass, and moisture flow within the soil. To rehabilitate a contaminated aquifer, contaminated groundwaters are withdrawn through drainage wells, PCBs are extracted with solvents or activated carbon and treated by chemical, photochemical or thermal methods. The chemical and photochemical methods are reviewed, but primary emphasis is devoted to the use of incineration as the preferred method of disposal. After discussing the formation of PCDFs and PCDDs during combustion from chloroaromatic, chloroaliphatic, as well as organic and inorganic chloride precursors, performance characteristics of different thermal destructors are presented and analyzed. To understand how this information can be used, basic design equations are developed from governing heat and mass balances that can be applied to the construction of incinerators capable of more than 99.99% destruction with minimal to nondetectable levels of PCDFs and PCDDs. PMID:3921358

  7. Passive sampling provides evidence for Newark Bay as a source of polychlorinated dibenzo-p-dioxins and furans to the New York/New Jersey, USA, atmosphere.

    PubMed

    Friedman, Carey L; Cantwell, Mark G; Lohmann, Rainer

    2012-02-01

    Freely dissolved and gas phase polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were measured in the water column and atmosphere at five locations within Newark Bay (New Jersey, USA) from May 2008 to August 2009 with polyethylene (PE) passive samplers. Mono- to octa-CDDs and mono- to hepta-CDFs were detected in bottom and surface waters at ≤ 20 pg/L with no clear gradient between sampling locations, suggesting freely dissolved PCDD/Fs are well mixed in Newark Bay. The most concentrated, freely dissolved gas phase congener was 2,7/2,8-dichlorodibenzo-p-dioxin (2,7/2,8-DiCDD), likely originating from photochemical conversion of triclosan in Newark Bay. Air-surface water gradients strongly favored net volatilization of PCDD/PCDFs from Newark Bay. Water-to-air fluxes of 2,7/2,8-DiCDD and 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), the most concentrated and the most toxic PCDD/PCDFs, respectively, were approximately 60 ng/m(2) per month and 14 to 51 pg/m(2) per month. Significant decreases in freely dissolved 2,3,7,8-TCDD concentrations with increasing freshwater near the Passaic River and conservative behavior during the summer of 2009 suggested Passaic sediments as a likely source of 2,3,7,8-TCDD to Newark Bay. Mass balance calculations implied that almost 50% of freely dissolved 2,3,7,8-TCDD delivered to Newark Bay from the Hackensack and Passaic Rivers was lost to volatilization in the summer of 2009.

  8. Distribution and elimination of polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, and p,p'-DDE in tissues of bald eagles from the Upper Peninsula of Michigan.

    PubMed

    Kumar, Kurunthachalam Senthil; Kannan, Kurunthachalam; Giesy, John P; Masunaga, Shigeki

    2002-07-01

    Liver, muscle, fat, kidney, and gall bladder of eight bald eagles (Haliaeetus leucocephalus) found dead in the Upper Peninsula of Michigan during 2000 were analyzed for the presence of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (including coplanar PCBs), p,p'-DDE, and hexachlorobenzene (HCB). Necropsy results showed that the birds suffered from peritonitis, bacterial infection, or trauma. Concentrations of PCDD/DFs in livers ranged from 23 to 4500 pg/g on a wet weight basis (wet wt), whereas the least concentrations were found in blood plasma of bald eagle nestlings (2.3-49 pg/g, wet wt). A maximum total PCB concentration of 280,000 ng/g, wet wt, was found in the liver of a dead bald eagle affected by peritonitis. The greatest concentrations of p,p'-DDE and HCB in eagle livers were 17,000 and 120 ng/g, wet wt, respectively. Eagles with elevated 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or total PCB concentrations tended to have great TCDD/TCDF or PCB126/PCB77 ratios, hypothesized to be due to induction of cytochrome P450 enzymes and subsequent metabolism of TCDF and PCB77. Concentrations of TCDD toxic equivalents (TEQs) in the tissues of bald eagles exceeded the thresholds for toxicity in a few avian species. Non-ortho coplanar PCBs accounted for 68-88% of the total TEQs in bald eagle tissues. PCDDs and PCDFs collectively accounted for, on average, 17% of the total TEQs. On the basis of the analysis of a single gall bladder with bile, biliary excretion rates of PCDDs, PCDFs, and PCBs were estimated as 0.015-0.02% per day.

  9. Exposure and effects assessment of resident mink (Mustela vison) exposed to polychlorinated dibenzofurans and other dioxin-like compounds in the Tittabawassee River basin, Midland, Michigan, USA.

    PubMed

    Zwiernik, Matthew J; Kay, Denise P; Moore, Jeremy; Beckett, Kerrie J; Khim, Jong Seong; Newsted, John L; Roark, Shaun A; Giesy, John P

    2008-10-01

    Historically, sediments and floodplain soils of the Tittabawassee River (TR; MI, USA) have been contaminated with polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated biphenyls (PCBs). Median concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) based on 2006 World Health Organization tetrachlorodibenzo-p-dioxin toxic equivalency factors (TEFs) in the diet of mink (Mustela vison) ranged from 6.8 x 10(-1) ng TEQ/kg wet weight upstream of the primary source of PCDF to 3.1 x 10(1) ng TEQ/kg wet weight downstream. Estimates of toxicity reference values (TRVs) derived from laboratory studies with individual PCDDs/PCDFs and PCB congeners or mixtures of those congeners, as well as application of TEFs, were compared to site-specific measures of mink exposure. Hazard quotients based on exposures expressed as concentrations of TEQs in the 95th percentile of the mink diet or liver and the no-observable-adverse-effect TRVs were determined to be 1.7 and 8.6, respectively. The resident mink survey, however, including number of mink present, morphological measures, sex ratios, population age structure, and gross and histological tissue examination, indicated no observable adverse effects. This resulted for multiple reasons: First, the exposure estimate was conservative, and second, the predominantly PCDF congener mixture present in the TR appeared to be less potent than predicted from TEQs based on dose-response comparisons. Given this, there appears to be great uncertainty in comparing the measured concentrations of TEQs at this site to TRVs derived from different congeners or congener mixtures. Based on the lack of negative outcomes for any measurement endpoints examined, including jaw lesions, a sentinel indicator of possible adverse effects, and direct measures of effects on individual mink and their population, it was concluded that current concentrations of PCDDs/PCDFs were not causing adverse effects on

  10. Levels and trends of organochlorines and brominated flame retardants in ivory gull eggs from the Canadian Arctic, 1976 to 2004.

    PubMed

    Braune, Birgit M; Mallory, Mark L; Grant Gilchrist, H; Letcher, Robert J; Drouillard, Ken G

    2007-06-01

    The ivory gull (Pagophila eburnea) is a circumpolar marine bird which has recently been listed as an endangered species in Canada. To determine whether contaminants may be playing a role in the population decline of this species, ivory gull eggs collected in 1976, 1987 and 2004 from Seymour Island in the Canadian Arctic were analyzed for organochlorines, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs. This study also provides the first account of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs) and polybrominated biphenyls (PBBs) in ivory gulls. The most quantitatively abundant legacy organochlorines found in the ivory gull eggs were p,p'-DDE, SigmaPCB and oxychlordane. Concentrations of the organochlorines analyzed either decreased or showed little change between 1976 and 2004. Concentrations of SigmaPCDD in ivory gull eggs were greater than SigmaPCDF, and the non-ortho PCBs (primarily PCB-126) contributed the largest fraction to the total TEQ value in all years sampled. Concentrations of PCDDs, PCDFs and SigmaTEQ decreased from 1976 to 2004. In contrast, concentrations of the PBDEs steadily increased between 1976 and 2004 driven primarily by increases in BDE-47. Although concentrations of the persistent chlorinated compounds (i.e. organochlorine pesticides, PCBs, PCDDs, PCDFs) reported in this study were below published toxicological threshold values for eggs of wild birds, we cannot rule out the possibility of synergistic/additive, sublethal effects. Very few studies have been carried out to evaluate the exposure-effect relationship of the persistent brominated compounds in avian species. Given the scarcity of information on toxicity threshold levels for PBBs and PBDEs in avian species, coupled with the trend toward increasing concentrations in ivory gulls, continued monitoring and further toxicological studies of these compounds are warranted.

  11. Pulmonary bioavailability and fine particle enrichment of 2,3,7,8-tetrachlorodibenzo-p-dioxin in respirable soil particles

    SciTech Connect

    Nessel, C.S.; Amoruso, M.A.; Umbreit, T.H.; Meeker, R.J.; Gallo, M.A. )

    1992-08-01

    The pulmonary bioavailability of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the enrichment of polychlorinated dioxins (PCDDs) and furans (PCDFs) in fine particles were evaluated to assess the implications that these factors have on risk and exposure assessments. Respirable subfractions of PCDD-contaminated soil from a former 2,4,5-trichlorophenoxyacetic acid manufacturing site were isolated by chemical dispersion and gravity sedimentation. Analysis of the subfractions revealed that there was a size-dependent enrichment of PCDDs and PCDFs, with smaller particles more highly contaminated. TCDD was enriched up to 33-fold as compared to unfractionated soil. Soil and laboratory-recontaminated gallium oxide, which served as the positive control, were administered by intratracheal instillation to female Sprague-Dawley rats. Animals were terminated up to 28 days following treatment and pulmonary bioavailability of TCDD was assessed by hepatic enzyme induction and TCDD concentration. Enzyme induction was dependent on the duration of exposure with up to 56 and 918% increases in cytochrome P450 and aryl hydrocarbon hydroxylase (AHH) activity, respectively, following exposure to PCDD-contaminated soil. There was no significant difference in AHH induction between animals which received contaminated soil and those treated with the positive control. Hepatic concentration of TCDD in soil-exposed rats was 115, 101, and 179% of positive controls at 1, 7, and 28 days post-treatment, suggesting that the soil or cocontaminants influenced retention of TCDD in the liver. These data indicate that the relative pulmonary bioavailability of TCDD on respirable soil particles is 100% as compared to laboratory-recontaminated gallium oxide and that PCDDs and PCDFs are highly enriched on respirable particles.

  12. Exposure and effects assessment of resident mink (Mustela vison) exposed to polychlorinated dibenzofurans and other dioxin-like compounds in the Tittabawassee River basin, Midland, Michigan, USA.

    PubMed

    Zwiernik, Matthew J; Kay, Denise P; Moore, Jeremy; Beckett, Kerrie J; Khim, Jong Seong; Newsted, John L; Roark, Shaun A; Giesy, John P

    2008-10-01

    Historically, sediments and floodplain soils of the Tittabawassee River (TR; MI, USA) have been contaminated with polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated biphenyls (PCBs). Median concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) based on 2006 World Health Organization tetrachlorodibenzo-p-dioxin toxic equivalency factors (TEFs) in the diet of mink (Mustela vison) ranged from 6.8 x 10(-1) ng TEQ/kg wet weight upstream of the primary source of PCDF to 3.1 x 10(1) ng TEQ/kg wet weight downstream. Estimates of toxicity reference values (TRVs) derived from laboratory studies with individual PCDDs/PCDFs and PCB congeners or mixtures of those congeners, as well as application of TEFs, were compared to site-specific measures of mink exposure. Hazard quotients based on exposures expressed as concentrations of TEQs in the 95th percentile of the mink diet or liver and the no-observable-adverse-effect TRVs were determined to be 1.7 and 8.6, respectively. The resident mink survey, however, including number of mink present, morphological measures, sex ratios, population age structure, and gross and histological tissue examination, indicated no observable adverse effects. This resulted for multiple reasons: First, the exposure estimate was conservative, and second, the predominantly PCDF congener mixture present in the TR appeared to be less potent than predicted from TEQs based on dose-response comparisons. Given this, there appears to be great uncertainty in comparing the measured concentrations of TEQs at this site to TRVs derived from different congeners or congener mixtures. Based on the lack of negative outcomes for any measurement endpoints examined, including jaw lesions, a sentinel indicator of possible adverse effects, and direct measures of effects on individual mink and their population, it was concluded that current concentrations of PCDDs/PCDFs were not causing adverse effects on

  13. Destruction of DDT wastes in two preheater/precalciner cement kilns in China.

    PubMed

    Yan, Dahai; Peng, Zheng; Karstensen, Kåre Helge; Ding, Qiong; Wang, Kaixiang; Wang, Zuguang

    2014-04-01

    The destruction of DDT formulations and DDT contaminated soil was conducted by feeding wastes into the flue gas chamber at the kiln inlet of two different preheater/precalciner cement kilns in China. The concentration of DDT, PCDD/PCDFs and HCB were measured in the flue gas of the main stack, in the solid material under baseline conditions and when feeding DDT-wastes. The destruction efficiency and the destruction and removal efficiency for DDT were in the range of 99.9335%-99.9998% and 99.9984%-99.9999%, respectively. The emissions of PCDD/PCDFs and HCB in the flue gas varied in the range of 0.0019-0.0171 ng I-TEQ/Nm(3) and 0.0064-0.0404 μg/Nm(3), respectively. The emission factor for PCDD/PCDF and HCB varied from 0.0137 to 0.0281 μg/ton and from 17.32 to 109.34 μg/ton of clinker, respectively. The concentration of PCDD/PCDFs and HCB in solid samples decreased as follows: cement kiln dust, 4.1-5 ng I-TEQ/kg and 0.70-0.71 μg/kg, respectively; >raw meal, 0.82-0.97 ng I-TEQ/kg and 0.18 μg/kg, respectively; >cement clinker, 0.09-0.22 ng I-TEQ/kg and 0.14-0.18 μg/kg, respectively. This study indicates that the feeding of DDT and POPs-wastes to the lower temperature part of a cement kiln system possibly to create a buildup of trace not-destroyed compounds in the system and might cause emissions; the technical feasibility and the environmental acceptability of this practice need to be investigated thoroughly. PMID:24468499

  14. The Role of Hydrology in the Polychlorinated Dibenzo--dioxin and Dibenzofuran Distributions in a Lowland River.

    PubMed

    Urbaniak, Magdalena; Kiedrzyńska, Edyta; Kiedrzyński, Marcin; Zieliński, Marek; Grochowalski, Adam

    2015-07-01

    Persistent organic pollutants such as polychlorinated dibenzo--dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are environmental contaminants that have widespread distribution and pose a serious threat to aquatic ecosystems. We conducted a study to quantify the distribution, patterns, and transport of PCDDs and PCDFs along the Pilica River in central Poland under different hydrological conditions to estimate the loads of these compounds and understand their fate in aquatic systems. Water samples were collected at five sampling points along the river that represent a range of hydrological conditions including flooding and stable and low water flows. Reduced river water flow was associated with lower average total and toxic equivalent (TEQ) concentrations of PCDDs plus PCDFs: 33.6 pg L and 4.21 pg TEQ L for flooding; 28.3 pg L and 3.6 pg TEQ L for stable flow; 18.4 pg L and 1.0 pg TEQ L for low-water flow. Similar results were observed for daily loadings of total and TEQ concentrations: the highest values were observed during flooding (331.1-839.4 mg d and 27.8-110.7 mg TEQ d), medium under stable hydrological conditions (55.8-121.0 mg d and 7.7-15.3 mg TEQ d), and the lowest values during low water flow (30.9 and 40.3 mg d and 1.4-2.4 mg TEQ d). The results demonstrate that diffuse sources of pollution play a key role during periods of high water flow (i.e., flooding season), whereas point sources of pollution, including municipal and industrial wastewater treatment plant discharges, mainly determine the PCDD and PCDF concentrations seen during low water periods. PMID:26437098

  15. Formation and potential mechanisms of polychlorinated dibenzo-p-dioxins and dibenzofurans on fly ash from a secondary copper smelting process.

    PubMed

    Wang, Mei; Liu, Guorui; Jiang, Xiaoxu; Xiao, Ke; Zheng, Minghui

    2015-06-01

    Secondary copper smelting (SeCu) is widely considered to be an important source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs; PCDD/Fs). Laboratory experiments were performed using SeCu fly ash as a matrix for thermochemical reactions to investigate the effects of fly ash on the formation of PCDD/Fs and the potential mechanisms. Thermochemical reactions on SeCu fly ash over a temperature range of 250-450 °C and reaction times of 10-120 min caused the PCDD/F concentrations in the fly ash to increase significantly. The PCDD/F concentrations formed in the thermal reactions were about 99-139 times higher than the PCDD/F concentrations in the original fly ash, clearly indicating that fly ash promoted the formation of PCDD/Fs. The PCDFs dominated the PCDDs, and the PCDF/PCDD concentration ratio was about 30-40. Octachlorodibenzofuran (OCDF), octachlorodibenzo-p-dioxin, and the heptachlorodibenzofurans were the most dominant homologs that were formed. A comparison of the PCDD/F patterns produced in the thermochemical reactions and the patterns in the original fly ash suggested that the chlorination of less chlorinated PCDFs might be an important pathway in the formation of higher chlorinated furans. The results of this study indicated that SeCu fly ash has a high PCDD/F formation potential. It is crucial to have the fly ash filter at low temperature and that fly ash in the cooling system should be minimized.

  16. Destruction of DDT wastes in two preheater/precalciner cement kilns in China.

    PubMed

    Yan, Dahai; Peng, Zheng; Karstensen, Kåre Helge; Ding, Qiong; Wang, Kaixiang; Wang, Zuguang

    2014-04-01

    The destruction of DDT formulations and DDT contaminated soil was conducted by feeding wastes into the flue gas chamber at the kiln inlet of two different preheater/precalciner cement kilns in China. The concentration of DDT, PCDD/PCDFs and HCB were measured in the flue gas of the main stack, in the solid material under baseline conditions and when feeding DDT-wastes. The destruction efficiency and the destruction and removal efficiency for DDT were in the range of 99.9335%-99.9998% and 99.9984%-99.9999%, respectively. The emissions of PCDD/PCDFs and HCB in the flue gas varied in the range of 0.0019-0.0171 ng I-TEQ/Nm(3) and 0.0064-0.0404 μg/Nm(3), respectively. The emission factor for PCDD/PCDF and HCB varied from 0.0137 to 0.0281 μg/ton and from 17.32 to 109.34 μg/ton of clinker, respectively. The concentration of PCDD/PCDFs and HCB in solid samples decreased as follows: cement kiln dust, 4.1-5 ng I-TEQ/kg and 0.70-0.71 μg/kg, respectively; >raw meal, 0.82-0.97 ng I-TEQ/kg and 0.18 μg/kg, respectively; >cement clinker, 0.09-0.22 ng I-TEQ/kg and 0.14-0.18 μg/kg, respectively. This study indicates that the feeding of DDT and POPs-wastes to the lower temperature part of a cement kiln system possibly to create a buildup of trace not-destroyed compounds in the system and might cause emissions; the technical feasibility and the environmental acceptability of this practice need to be investigated thoroughly.

  17. Levels and trends of organochlorines and brominated flame retardants in ivory gull eggs from the Canadian Arctic, 1976 to 2004.

    PubMed

    Braune, Birgit M; Mallory, Mark L; Grant Gilchrist, H; Letcher, Robert J; Drouillard, Ken G

    2007-06-01

    The ivory gull (Pagophila eburnea) is a circumpolar marine bird which has recently been listed as an endangered species in Canada. To determine whether contaminants may be playing a role in the population decline of this species, ivory gull eggs collected in 1976, 1987 and 2004 from Seymour Island in the Canadian Arctic were analyzed for organochlorines, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs. This study also provides the first account of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs) and polybrominated biphenyls (PBBs) in ivory gulls. The most quantitatively abundant legacy organochlorines found in the ivory gull eggs were p,p'-DDE, SigmaPCB and oxychlordane. Concentrations of the organochlorines analyzed either decreased or showed little change between 1976 and 2004. Concentrations of SigmaPCDD in ivory gull eggs were greater than SigmaPCDF, and the non-ortho PCBs (primarily PCB-126) contributed the largest fraction to the total TEQ value in all years sampled. Concentrations of PCDDs, PCDFs and SigmaTEQ decreased from 1976 to 2004. In contrast, concentrations of the PBDEs steadily increased between 1976 and 2004 driven primarily by increases in BDE-47. Although concentrations of the persistent chlorinated compounds (i.e. organochlorine pesticides, PCBs, PCDDs, PCDFs) reported in this study were below published toxicological threshold values for eggs of wild birds, we cannot rule out the possibility of synergistic/additive, sublethal effects. Very few studies have been carried out to evaluate the exposure-effect relationship of the persistent brominated compounds in avian species. Given the scarcity of information on toxicity threshold levels for PBBs and PBDEs in avian species, coupled with the trend toward increasing concentrations in ivory gulls, continued monitoring and further toxicological studies of these compounds are warranted. PMID:17412396

  18. Biomarkers for Great Lakes priority contaminants: halogenated aromatic hydrocarbons.

    PubMed Central

    Feeley, M M

    1995-01-01

    One of the major goals of the Great Lakes Action Plan is to actively accumulate and assess toxicological information on persistent toxic substances found in the Great Lakes basin. As part of Health Canada's commitment to this plan, a review of biomarkers for the environmental contaminants polychlorinated biphenyls (PCBs) and polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs) was conducted. In general, while food consumption was identified as the major source of human exposure to both contaminant groups, certain commodities, such as fish, milk and dairy products, and meat, were found to predominate. Due to the ubiquitous nature of these environmental contaminants and their propensity to bioaccumulate, all humans will have detectable body burdens, which in certain cases can be positively associated with the consumption of particular foods (i.e., PCBs and freshwater fish from the Great Lakes). When dealing with environmental exposure only, relating specific effect biomarkers to contaminant exposure or tissue levels was difficult, due in part to the complex nature of the exposure and the nonspecific nature of the effect. For PCBs, the most likely biomarkers of effect included some form of alteration in lipid metabolism (serum triglyceride/cholesterol levels) and elevation of hepatic-related enzymes, aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT). Cross-species extrapolation also indicates the potential for neurotoxicologic effects to occur in humans. For PCDDs/PCDFs, dermatologic lesions (chloracne) and indications of hepatic enzyme induction have been documented, but primarily due to occupational or high acute accidental exposures. Recent evidence suggests that neonates may represent a potential at-risk population due to relatively high exposure to PCDDs/PCDFs, as with PCBs, during breast feeding as compared to standard adult dietary intake. Future areas of potential benefit for biomarker development include immunologic and endocrine

  19. The Role of Hydrology in the Polychlorinated Dibenzo--dioxin and Dibenzofuran Distributions in a Lowland River.

    PubMed

    Urbaniak, Magdalena; Kiedrzyńska, Edyta; Kiedrzyński, Marcin; Zieliński, Marek; Grochowalski, Adam

    2015-07-01

    Persistent organic pollutants such as polychlorinated dibenzo--dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are environmental contaminants that have widespread distribution and pose a serious threat to aquatic ecosystems. We conducted a study to quantify the distribution, patterns, and transport of PCDDs and PCDFs along the Pilica River in central Poland under different hydrological conditions to estimate the loads of these compounds and understand their fate in aquatic systems. Water samples were collected at five sampling points along the river that represent a range of hydrological conditions including flooding and stable and low water flows. Reduced river water flow was associated with lower average total and toxic equivalent (TEQ) concentrations of PCDDs plus PCDFs: 33.6 pg L and 4.21 pg TEQ L for flooding; 28.3 pg L and 3.6 pg TEQ L for stable flow; 18.4 pg L and 1.0 pg TEQ L for low-water flow. Similar results were observed for daily loadings of total and TEQ concentrations: the highest values were observed during flooding (331.1-839.4 mg d and 27.8-110.7 mg TEQ d), medium under stable hydrological conditions (55.8-121.0 mg d and 7.7-15.3 mg TEQ d), and the lowest values during low water flow (30.9 and 40.3 mg d and 1.4-2.4 mg TEQ d). The results demonstrate that diffuse sources of pollution play a key role during periods of high water flow (i.e., flooding season), whereas point sources of pollution, including municipal and industrial wastewater treatment plant discharges, mainly determine the PCDD and PCDF concentrations seen during low water periods.

  20. Amines compounds as inhibitors of PCDD/Fs de novo formation on sintering process fly ash.

    PubMed

    Xhrouet, Céline; Nadin, Caroline; De Pauw, Edwin

    2002-06-15

    The polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are highly toxic compounds produced by some natural processes and different human activities. Waste incineration as well as steel and iron industries, in particular, the sintering process, are among the principal sources of these pollutants. In this paper, two inhibitors, triethanolamine (TEA) and monoethanolamine (MEA) are tested relating to their abilityto prevent the de novo formation of PCDD/Fs on sinter plant fly ash. The amounts of both PCDDs and PCDFs, formed by thermal treatment of the fly ash, decrease when inhibitors are added. The best results, up to 90% reduction of the PCDD/ Fs formation, are obtained when MEA is mixed with the fly ash at the highest concentration tested (2 wt %). The addition of inhibitors modifies the PCDFs/PCDDs ratios and, under some experimental conditions, the PCDD/Fs homologue distributions, suggesting that more than one pathway for the de novo formation of PCDD/Fs exist. On the other hand, no modification in the PCDD/Fs isomer distributions is observed as a result of the addition of inhibitors, in accordance with the possible thermodynamic control of these distributions. The temperature tested, 325 and 400 degrees C, does not affect the inhibition activity; however, longer reaction times (4 h instead of 2 h) give better percentages of PCDD/Fs reduction. The results suggest that the two inhibitors and especially MEA can reduce the PCDD/Fs formation on sinter plant fly ash under various conditions of temperature and reaction time, making them suitable for use in the real process. Tests performed in parallel at a real sinter plant are in good agreement with the laboratory experiments and confirm that the use of inhibitors is an appropriate technique for the prevention of PCDD/Fs emissions from sintering processes.

  1. Temporal trends in polychlorinated dibenzo-p-dioxins and dibenzofurans, dioxin-like PCBs, and polybrominated diphenyl ethers in Niagara river suspended sediments.

    PubMed

    Marvin, Chris; Williams, Donald; Kuntz, Ken; Klawunn, Paul; Backus, Sean; Kolic, Terry; Lucaciu, Corina; MacPherson, Karen; Reiner, Eric

    2007-04-01

    Archived suspended sediment samples collected over the period 1980-2002 at Niagara-on-the-Lake in the Niagara river were analyzed to assess temporal trends in contaminants associated with historical industrial activities in the watershed (PCDDs/PCDFs, DLPCBs), compared to more modern industrial chemicals (PBDEs). The temporal trends for PCDDs/PCDFs and DLPCBs were generally similar, and showed a general trend toward decreasing concentrations, which was presumably due to implementation of control measures in the Niagara river watershed, including the remediation of hazardous waste facilities. The temporal trend in PBDEs contrasted with those of PCDDs/PCDFs and DLPCBs. Prior to 1988, PBDEs (sum of 16 congeners including deca-BDE) were generally detected at low-ppb concentrations, but showed a trend toward increasing concentrations over the period 1980-1988. After 1988, PBDE concentrations in the Niagara river showed a more rapidly increasing trend to a maximum of approximately 35 ng/g in 1995, with deca-BDE as the predominant congener detected. Samples collected over the period February 2003 to March 2004 at the head and mouth of the Niagara river were also analyzed for PBDEs; in all cases PBDE concentrations were higher at the mouth of the river at the outflow to Lake Ontario, indicating the Niagara river watershed is a source of PBDE contamination to Lake Ontario. However, PBDE concentrations in suspended sediments of the Niagara river were comparable to, or lower than, concentrations in bottom sediments in other industrialized/urbanized areas of the world. Based on these comparisons of global PBDE bottom sediment concentrations, the Niagara river watershed does not appear to be a significant local source of PBDEs to Lake Ontario, and concentrations in suspended sediments appear to be indicative of general PBDE contamination from a contamination of local, regional, and continental sources.

  2. PCDD, PCDF, PCB and PBDE concentrations in breast milk of mothers residing in selected areas of Slovakia.

    PubMed

    Chovancová, Jana; Čonka, Kamil; Kočan, Anton; Sejáková, Zuzana Stachová

    2011-05-01

    The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs) and polybrominated diphenylethers (PBDEs) in 33 breast milk samples collected in 2006-2007 from primipara mothers close to four industrial areas of Slovak Republic were determined. The total PCDDs/PCDFs and dl-PCBs expressed as TEQ based on WHO TEFs 1998 in breast milk samples varied from 5.0 to 51.8 pg g(-1) fat (median: 13.1 pg g(-1) fat; mean: 18.0 pg g(-1) fat). The measurements of seven PBDE congeners (IUPAC No. 28, 47, 99, 100, 153, 154, and 183) were performed for the first time in human milk from Slovakia. PBDE levels ranged between 0.22 and 1.62 ng g(-1) fat, with median and mean value of 0.43 ng g(-1) fat and 0.57 ng g(-1) fat respectively. No statistically significant differences were observed between studied areas in total PBDE concentrations. Furthermore, this study presents first results concerning the daily intake (DI) of PCDDs/PCDFs and dioxin-like compounds for the most vulnerable breast-fed infant population in Slovakia. The total PCDD/PCDF and dl-PCB DI for an infant during the first 2 months of life was estimated in a range from 14.4 to 230 pg TEQ kg(-1)b.w., with a median value of 58.9 pg TEQ kg(-1)b.w.. The DI values substantially exceeded the tolerable daily intake (TDI) 1-4 pg TEQ kg(-1)b.w. recommended by WHO. The dietary infant intake concerning PBDEs was estimated to be between 0.69 and 7.1 ng kg(-1)b.w.d(-1), with median value of 1.7 ng kg(-1)b.w.d(-1).

  3. Polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in livers of birds from Japan.

    PubMed

    Senthilkumar, K; Iseki, N; Hayama, S; Nakanishi, J; Masunaga, S

    2002-02-01

    Concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and non- and mono-ortho-chlorine-substituted polychlorinated biphenyls (dioxin-like PCBs) were measured in livers of 17 species of birds collected from Japan. Birds were grouped according to their feeding habits as granivores, piscivores, omnivores, and predators for discussions. Livers of granivores contained relatively low concentrations of PCDD/DFs (80-660 pg/g) followed in increasing order by omnivores (2,300-8,000 pg/g), piscivores (61-12,000 pg/g) and predators (480-490,000 pg/g on a fat weight basis). Especially, one species of predatory bird (mountain hawk eagle) contained elevated concentrations of PCDDs, PCDFs, and dioxin-like PCBs, and the measured concentration is one of the highest reported to date. Homolog and congener patterns of PCDDs and PCDFs varied among species; hence, the results suggested that feeding habits, specific elimination, and metabolism influence contamination pattern. Concentrations of dioxin-like PCBs were in the order of granivores (32-83 ng/g) < predators [excluding mountain hawk eagle] (32-2,500 ng/g) < piscivore (61-12,000 ng/g) < omnivores (1,800-67,000 ng/g on a fat weight basis). Mountain hawk eagle contained the highest concentration of dioxin-like PCBs (55,000 ng/g fat weight). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalents (TEQs) ranged from 53-450,000 pg/g fat weight. 23478-PeCDF, 2378-TCDD/TCDF, and PCB congeners IUPAC 126 and 77 were major contributors to TEQs in birds. To our knowledge, this is the first study of PCDD/DFs and dioxin-like PCBs in livers of several species of Japanese birds.

  4. Dioxin-like PCBs and PCDD/Fs in surface sediments near the shore of Winam Gulf, Lake Victoria.

    PubMed

    Omwoma, Solomon; Lalah, Joseph O; Virani, Munir; Schramm, Karl-Werner; Henkelmann, Bernhard

    2015-01-01

    Winam Gulf of Lake Victoria is considered to be contaminated with toxic chemicals emanating from anthropogenic activities, especially near large industrial towns such as Kisumu. This has recently caused concerns about its water quality and impact on aquatic organisms and human beings. This study was justified by the need to generate baseline concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in surface sediment from selected sites in the lake and determine the influence of activities on their concentrations and potential risks to fish-eating birds living near the lake. Surface sediments (<30cm) from three different fish landing beaches, located 200m from the shore of Winam Gulf of Lake Victoria near Kisumu city, Homa Bay and Mbita (control) towns, were analysed. The total mean concentrations (in pgg(-1)drywt) were found to range from 17.4-812 (Σdl-PCBs), 36.6-813 (ΣPCDDs) and 1.45-46.4 (ΣPCDFs). The calculated Toxic Equivalents (TEQWHO(2005)) ranged from 0.001-0.43 (Σdl-PCBs) and 0.09-31 (ΣPCDD/Fs). The fish landing beaches at Kisumu city were found to be contaminated with respect to dl-PCBs and dioxins, followed by Homa Bay and Mbita. The relatively high levels of octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) influenced the TEQ and the ΣPCDFs/ΣPCDDs ratios indicated chemical processes as partial sources of the dioxins. The levels of contaminants obtained in this study showed potential exposure to aquatic organisms and fish eating birds through food chain transfer.

  5. Endangered Vancouver Island marmots (Marmota vancouverensis): sentinels of atmospherically delivered contaminants to British Columbia, Canada.

    PubMed

    Lichota, Gillian B; McAdie, Malcolm; Ross, Peter S

    2004-02-01

    We characterized legacy and new contaminants in the highly endangered Vancouver Island (British Columbia, Canada) marmot and found generally low blood and fat concentrations of a complex mixture of pesticides, polychlorinated biphenyls (PCBs), -dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs), polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), and polychlorinated naphthalenes (PCNs) in their tissues. The dominance of the more volatile alpha-hexachlorocyclohexane (HCH) and hexachlorobenzene (HCB) pesticides and the lesser chlorinated PCB congeners suggests that atmospheric processes largely explain the contamination of this high-altitude herbivore.

  6. Results of the combustion and emissions research project at the VICON incinerator facility in Pittsfield, Massachusetts: Draft final report: Volume 1, Text

    SciTech Connect

    Not Available

    1987-02-18

    Airborne emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) can be produced as a result of incomplete combustion of municipal solid waste (MSW). However, knowledge is limited about the incinerator design and operating conditions which cause these compounds to be formed or which can be adjusted to minimize or eliminate their discharge. In addition, the chemical forms of chlorine and precursors which may contribute to the formation of PCDD and PCDF are not clearly known. This study focuses on determining the relationships between incinerator combustion/operating variables, refuse characteristics, and emission levels of PCDD and PCDF, as well as selected potential precursor compounds.

  7. Hepatic cytochrome P450 1A as a biomarker for hydrocarbon and oxidant pollutants in fish: Relevance of identification of specific mechanism(s) of induction and potential effects on homeostasis

    SciTech Connect

    Zacharewski, T.R.; McCallum, G.P.; Bend, J.R.; Stegeman, J.J.

    1996-12-31

    The induction of hepatic and extrahepatic P450 1A isozymes in fish and mammals is used as a biomarker for certain classes of toxic environmental pollutants, including polycyclic aromatic hydrocarbons (PAHs), planar polychlorinated (PCBs) and polybrominated (PBBs) biphenyl congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). However, recent data from the laboratory have shown that rat pulmonary P450 1A1 can also be induced by arsenite or liver transplantation (via a stress mechanism), raising the possibility that regulation of this biomarker can occur by mechanisms other than Ah receptor-mediated increases of CYP1A gene transcription.

  8. Workshop on perinatal exposure to dioxin-like compounds. III. Endocrine effects

    SciTech Connect

    Feeley, M.M.

    1995-03-01

    Studies involving endocrine effects in humans and experimental animals resulting from the exposure to dioxin-like (non-ortho-substituted PCBs, PCDDs/PCDFs) and nondioxin-like (PCBs, OC pesticides) compounds (DLCs and NDLCs) were presented. A variety of reproductive and hormonal parameters, including androgen status, sexual differentiation, and thyroid functionality, were discussed. As in utero and lactational exposure of the human fetus/neonate to these environmental contaminants is inevitable, continued research to identify sensitive biomarkers of effect and susceptibility as well as to define dose-response relationships is required. 15 refs., 1 fig.

  9. 2,3,7,8,-tetrachlorodibenzo-p-dioxin equivalents in tissues of birds at Green Bay, Wisconsin, USA

    SciTech Connect

    Jones, P.D.; Giesy, J.P.; Newsted, J.L.; Verbrugge, D.A.; Beaver, D.L.

    1993-01-01

    The environment has become contaminated with complex mixtures of planar, chlorinated hydrocarbons (PCHs) such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and structurally similar compounds. Because the potencies of individual congeners to cause the same adverse effects vary greatly and the relative as well as absolute concentrations of individual PCH vary among samples from different locations, it is difficult to assess the toxic effects of these mixtures on wildlife. These compounds can cause a number of adverse effects, however, because the toxic effects which occur at ecologically-relevant concentrations such as embryo-lethality and birth defects appear to be mediated through the same mechanism.

  10. Levels and profiles of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in feedstuffs and milk from farms in the vicinity of incineration plants in Tuscany, Italy.

    PubMed

    Ingelido, Anna Maria; Abballe, Annalisa; di Domenico, Alessandro; Fochi, Igor; Iacovella, Nicola; Saragosa, Alberto; Spagnesi, Maurizio; Valentini, Silvia; De Felip, Elena

    2009-08-01

    Levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorobiphenyls (PCBs) were determined in samples of bovine and ovine milk collected in farms located in the province of Grosseto, Tuscany, in the vicinity of two incineration plants as well as in farms located in areas with presumable background levels of contamination. Samples of feedstuffs of local origin used in the investigated farms were also collected and analysed. The cumulative levels of PCDDs, PCDFs, and dioxin-like PCBs (DL-PCBs) in feedstuffs ranged from 0.25 to 0.61 pg WHO-TE/g fresh weight (fw) in the farms under impact from incinerator emissions and from 0.21 to 0.34 pg WHO-TE/g fw in the control area farms. The sums of the six non-dioxin-like indicator PCB (NDL-PCB) congeners were 0.13 to 9.3 ng/g fw and 1.2 to 1.9 ng/g fw, respectively. In milk samples, the levels detected were 0.71 to 2.9 pg WHO-TE/g fat and 0.52 to 0.59 pg WHO-TE/g fat in farms under impact from the incinerators and in the control area farms, respectively. The corresponding sums of the six indicator PCB congeners were 1.4 to 8.2 ng/g fat and 0.90 to 1.6 ng/g fat. In all samples, contamination levels were below the limits set by the European Community (EC; Commission Directive 2006/13/EC and Commission Regulation 1881/2006/EC.) No relevant differences were found between samples collected in potentially exposed areas and control areas for total toxic equivalents and cumulative analytic levels of PCDDs, PCDFs, DL-PCBs, and NDL-PCBs (p > 0.05, Mann-Whitney U test). Observed levels were in agreement with those found in other countries in areas with background levels of exposure. Congener levels and profiles of PCDDs, PCDFs, and PCBs in feedstuffs and milk samples that were compared describe congener-specific transfer behavior.

  11. Consumption of fish: benefits and perceived risk

    SciTech Connect

    Kimbrough, R.D. )

    1991-05-01

    Fish, a useful source of protein, may be polluted by microbes, natural toxins, and/or synthetic chemicals. However, based on a review of the U.S. General Accounting Office, 'There does not appear to be a compelling case to implement a mandatory comprehensive federal seafood inspection program.' Although earlier studies showed higher body burdens of polychlorinated biphenyls (PCBs) in populations who consumed a lot of fish from polluted waterways, a recent study refutes these observations. No information is available in the United States on the levels of polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs) in anglers who consume a great deal of fish presumed to be contaminated by these chemicals.23 references.

  12. Exposure of arc-furnace-plant workers to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs).

    PubMed

    Chen, Hsiu-Ling; Shih, Tung-Sheng; Huang, Po-Chin; Hsieh, Chia-Yi; Lee, Ching-Chang

    2006-07-01

    This study aimed to evaluate serum polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) levels in electric-arc-furnace workers according to their corresponding occupational exposure. In addition, the ambient PCDD/Fs of the work environment were measured to provide additional support for the exposure and accumulation inside the electric arc furnace. The ambient PCDD/F concentrations inside the electric arc furnace were 1.557-1.917 pg-TEQ/Nm(3), 5-24 folds higher than those outside (0.080-0.385 pg-TEQ/N m(3)). In addition, higher average serum levels were measured in the workers with high occupational dioxin exposure (24.0 pg WHO-TEQ/g lipid) than in those with lower occupational dioxin exposure (13.8 pg WHO-TEQ/g lipid). Higher PCDFs/PCDDs ratios were found in serum samples from high-exposure groups than in low-exposure groups. The higher ratio of PCDFs/PCDDs was also found in ambient samples consistent with other metallurgical processes reported previously. Our results suggest that PCDD/Fs exposure exits in the smelting process of electric arc furnace, and the occupational hygiene should be taken more seriously concern in that workplace.

  13. Monitoring and estimating concentrations of polychlorinated biphenyls, dioxins, and furans in cattle milk and soils of Rhine-Delta floodplains.

    PubMed

    Hendriks, A J; Wever, H; Olie, K; van de Guchte, K; Liem, A K; van Oosterom, R A; van Zorge, J

    1996-08-01

    In the Rhine-Delta, accumulation of microcontaminants in floodplain foodwebs has received little attention in comparison with aquatic communities. Here, soil and cattle milk samples were taken from three floodplains and analyzed for polychlorinated biphenyls (PCBs), dibenzodioxins (PCDDs) and dibenzofurans (PCDFs). Based on 2,3,7, 8-tetrachlorodibenzodioxin equivalents, total PCDD and PCDF residues in milk did not exceed the quality standard of 0.006 microg/kg fat weight. This was still the case if non- and mono-ortho PCBs were added to the total. Yet, the floodplains investigated were only moderately polluted according to previous studies and one cannot exclude higher levels in milk from other floodplains. Bioconcentration ratios of milk fat vs soil organic matter were about 0.01 to 0.1 for persistent PCBs. These values are in accordance with a few literature data found for other persistent compounds. Yet, ratios are lower than expected from equilibrium partitioning. Ratios for PCDDs and PCDFs were even lower, possibly due to biotransformation.

  14. PCDDs/DFs emissions from crematories in Japan.

    PubMed

    Takeda, N; Takaoka, M; Fujiwara, T; Takeyama, H; Eguchi, S

    2000-03-01

    Concentrations of PCDDs and PCDFs in emission gases from 10 crematories were measured. The relationship between PCDDs/DFs and several factors such as structure, equipment and operational state of the crematory is discussed. Furthermore, emission of PCDDs/DFs from all crematories in Japan is estimated. The following results are obtained: (1) total concentration of PCDDs/DFs was 2.2-290 ng/N m3, whose TEQ concentration was 0.0099-6.5 ng TEQ/N m3; (2) total concentration of PCDFs was higher than that of PCDDs; (3) T4CDFs was the highest in the homologue pattern and 2,3,7,8-T4CDF was the highest in the isomer pattern; (4) emission of PCDDs/DFs was the largest in the first 20 min of cremation; (5) concentration of PCDDs/DFs was related to the existence of a secondary combustion chamber and a dust collector, and the ratio of the numbers of main and secondary combustion chambers; (6) total emission of PCDDs/DFs from crematories in Japan was estimated to be 8.9 g TEQ/yr.

  15. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran formation and emission in the thermal desorption waste treatment process

    SciTech Connect

    Leckey, J.H.

    1995-03-01

    It is extremely unlikely that significant amounts of polychlorinated dibenzo-p-dioxins (PCDDs) or polychlorinated dibenzofurans (PCDFs) will be emitted in the off-gas stream from the thermal desorption process, or the treated waste, particularly if the baseline design and anticipated operating conditions of the enhanced bench-scale (EBS) system are used. However, because of the acute toxicity of these compounds and because most of the data on their formation have been extrapolated from studies more related to incineration and fire conditions than thermal desorption, specific laboratory tests and specific EBS runs should be performed to monitor the rate of emission of PCDDs and PCDFs under thermal desorption conditions. In general, the following four conditions need to exist for significant amounts of PCDD or PCDF to be formed: (1) the presence of fly ash; (2) the presence of an oxidizing source; (3) a suitable temperature, and (4) the presence of a suitable precursor. Although the EBS system provides some of these conditions, it is unlikely that enough fly ash will be produced in the system to allow a significant amount of PCDD or PCDF formation. Additionally, particulate matter controls will be used to remove airborne particulates from the gas phase. If PCDD/Fs are presented in a waste stream being evaluated in the EBS, they will likely volatilize in the kiln and subsequently condense in the venturi scrubber system.

  16. Persistent organic pollutant concentrations in first birth mothers across Mexico.

    PubMed

    Rodríguez-Dozal, Sandra; Riojas Rodríguez, Horacio; Hernández-Ávila, Mauricio; Van Oostdam, Jay; Weber, Jean Philippe; Needham, Larry L; Trip, Luke

    2012-01-01

    This project was initiated by the North America Commission for Environmental Cooperation (CEC). Its main purpose was to obtain an initial profile on pregnant woman's exposure to persistent organic pollutants (POPs) in North America (Canada, the United States and Mexico). Persistent organic pollutants are transferred to the fetus via the placenta during the pregnancy or to the infant via maternal milk; therefore, the pregnant woman's body burden is important because of the higher exposures and potential health effects in the fetus and infant. This paper presents the results from 240 pregnant women in 10 Mexican cities, and includes the concentrations of various POPs such as polychlorinated biphenyls (PCBs), organochlorine pesticides and polychlorinated dibenzo dioxins and furans (PCDDs and PCDFs) in maternal plasma. We found concentrations of p,p'-DDE in maternal samples from Coatzacoalcos to be ∼60% higher than those found in Ciudad Obregon, which had the second highest concentration. Pregnant women from Merida had higher mean concentrations of PCBs than all women in other regions. Results for PCDDs and PCDFs plus dioxin-like PCBs data were only available on the basis of composite samples, and their concentrations are similar in most cities except for Coatzacoalcos, which had more than double the concentration found in other cities. Although this study provides useful information on the variability of POPs in specific populations and possible regional/local differences, these results cannot be generalized to the entire Mexican population because of differences in age, gender, sources of exposure and nonrandom nature of the sample.

  17. Dioxin registry report: walk-through survey of pentachlorophenol production facility at Vulcan Materials Company, Chemical Division, Wichita, Kansas

    SciTech Connect

    Marlow, D.; Fingerhut, M.

    1985-11-01

    A walkthrough survey of the pentachlorophenol (PCP) production facility at Vulcan Materials Company, Wichita, Kansas, August 1983 was conducted. The purpose of the survey was to determine if the PCP workers should be included in the Dioxin Registry. Breathing-zone and environmental samples were analyzed for PCP, polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). All PCP concentrations were below the OSHA standard of 0.5 milligram per cubic meter. Breathing zone PCDDs concentrations ranged from less than 0.008 to 1,067 nanograms per cubic meter. Bulk samples contained up to 893 micrograms per gram (microg/g) PCDDs and up to 12.7 microg/g PCDFs. The personnel department maintained files for all current and approximately 1,800 terminated employees. Medical files existed for terminated employees back to 1976. The company had a medical surveillance program for all employees provided by an outside contractor and employed a full time nurse. The facility had a well organized safety program. There was a formal set of general safety rules for the entire facility and a set of specific safety rules for each department. The authors conclude that the PCP workers at the facility should be included in the Dioxin Registry.

  18. Results of monitoring for polychlorinated dibenzo-p-dioxins and dibenzofurans in ambient air at McMurdo station, Antarctica

    SciTech Connect

    Lugar, R.M.; Harles, R.L.

    1996-02-01

    This paper presents the results of ambient air monitoring for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) performed during the 1992-1993 and 1993-1994 austral summers in the vicinity of McMurdo Station, Antarctica. Twenty-eight air samples were collected from four different locations to determine the identity and concentration of PCDD/PCDF compounds. PCDD/PCDF compounds were not detected at either the predominantly upwind location or a more remote site on Black Island. Trace levels of only a few PCDD/PCDF congeners were detected sporadically at a location approximately 500 m downwind of the station. The most frequent, most varied, and highest levels of PCDDs/PCDFs were measured at a `downtown` location, where concentrations of total PCDDs ranged from 0.12 to 1.80 pg/m{sup 3} and total PCDDs ranged from less than 0.02 to 2.77 pg/m{sup 3}. The data indicate that there are combustion sources at McMurdo other than the solid waste incinerator (power plants, vehicles, heating furnaces, etc.) that contribute PCDD/PCDF compounds to the ambient air. The greatest variety and highest concentration of PCDD/PCDF congeners measured in 1992-1993 during incineration of selected solid wastes implicates the interim incinerator as the likely source of the increased presence of these compounds in air. 18 refs., 2 figs., 3 tabs.

  19. Evaluation of a sampling and analysis method for determination of polyhalogenated dibenzo-p-dioxins and dibenzofurans in ambient air

    SciTech Connect

    Harless, R.L.; Lewis, R.G.; McDaniel, D.D.; Gibson, J.F.; Dupuy, A.E.

    1992-01-01

    General Metals Works PS-1 PUF air samplers and an analytical method based on high resolution gas chromatography - high resolution mass spectrometry (HRGC-HRMS) were evaluated for determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), polybrominated dibenz-p-dioxins and dibenzofurans (PBDDs/PBDFs) and bromo/chloro dibenzo-p-dioxins and dibenzofurans (BCDDs/BCDFs) in ambient air. Dilute solutions of these compounds and (13)C-1,2,3,4-TCDD were used to spike the filters of PS-1 air samplers which were then operated 24 hrs to sample 350-400 cubic meter ambient air. After sampling, each quartz-fiber filter and polyurethane foam (PUF) were spiked with (13)C-12-labeled PCDD, PCDF, PBDD, and PBDF internal standards before separate Soxhlet extractions with benzene. The extracts were subjected to an acid/base clean-up procedure followed by clean-up on microcolumns of silica gel, alumina, and carbon and then analyzed by HRGC-HRMS. Results derived from the study indicated the PS-1 ambient air samplers and the analytical procedures were very efficient and that pg/cubic meter and sub-pg/cubic meter levels of total PCDDs/PCDFs, PBDDs/PBDFs, BCDDs/BCDFs, and 2,3,7,8-substituted congeners could be accurately measured.

  20. Changes in contaminant distributions with trophic level in a marine food chain study

    SciTech Connect

    Pruell, R.J.; Johnson, M.W.; Taplin, B.K.; McGovern, D.G.; Montmarquet, B.T.

    1994-12-31

    A laboratory study was designed to investigate the transfer of chlorinated organic contaminants from sediments to marine biota in a simplified marine food chain. Sediments collected from the Passaic River, NJ, which contained high concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), PCBs and chlorinated pesticides, were used as the contamination source. Polychaete worms (Nereis virens) were exposed to Passaic River sediment for 70 days to allow steady-state concentrations to be achieved and then these organisms were fed to a crustacean, the American lobster (Homarus americanus). Contaminant distributions were altered significantly as they passed from sediments to polychaetes and then to the lobster. PCDDs and PCDFs containing four or five chlorines were accumulated by the polychaetes and lobster; however, the highly chlorinated congeners were not accumulated. PCB patterns in lobsters indicated that these organisms metabolized many PCB congeners. Coplanar PCBs did not appear to be metabolized and therefore became enriched relative to total PCB levels in the lobsters. Lobsters also greatly altered the ratios of chlordane and DDT series compounds relative to those in the sediments and polychaetes.

  1. Dibenzo-p-dioxins in the environment from ceramics and pottery produced from ball clay mined in the United States

    NASA Technical Reports Server (NTRS)

    Ferrario, Joseph; Byrne, Christian

    2002-01-01

    Processed ball clay samples used in the production of ceramics and samples of the ceramic products were collected and analyzed for the presence and concentration of the 2,3,7,8-Cl substituted polychlorinated dibenzo-p-dioxins and -furans (PCDDs/PCDFs). The processed ball clay had average PCDD concentrations of 3.2 ng/g toxic equivalents, a congener profile, and isomer distribution consistent with those found previously in raw ball clay. The PCDF concentrations were below the average limit of detection (LOD) of 0.5 pg/g. The final fired ceramic products were found to be free of PCDDs/PCDFs at the LODs. A consideration of the conditions involved in the firing process suggests that the PCDDs, if not destroyed, may be released to the atmosphere and could represent an as yet unidentified source of dioxins to the environment. In addition, the PCDDs in clay dust generated during manufacturing operations may represent a potential occupational exposure.

  2. Chlorinated hydrocarbon and mercury levels in bald eagles (Haliaeetus leucocephalus) found dead in British Columbia, 1988--1993

    SciTech Connect

    Elliott, J.E.; Wilson, L.K.; Norstrom, R.J.; Langelier, K.M.

    1994-12-31

    Liver samples from 70 bald eagles found dead or dying in British Columbia between 1988 and 1993 were analyzed for organochlorine and mercury levels. A subset of 11 eagles found around the Strait of Georgia, an area of known pulp mill pollution, in summer (and therefore presumably resident birds) were analyzed for polychlorinated dibenzo-p-dioxins (PCDDS) and polychlorinated dibenzofurans (PCDFs). Levels of DDE and PCBs ranged from less than 1 mg/kg to 190 and 65 mg/kg respectively. Levels of other organochlorines were generally less than 1 mg/kg, with the exception of some chlordane-related compounds which were occasionally over 2 mg/kg. All birds analyzed for PCDDs/PCDFs contained detectable levels of the major 2,378-substituted isomers. Some birds had extremely high levels, one eagle collected near a kraft pulp mill site contained: 400 ng/kg 2378-TCDD, 1400 ng/kg 12378-PnCDD and 4400 ng/kg 123678-HxCDD. All but two eagles had > 1 mg/kg dry wt. of mercury in liver; most contained less than 1 0 mg/kg d.w. but one bird had 130 mg/kg, a level of toxicological concern. All carcasses were autopsied and cause of death determined wherever possible. The relationship between cause of death and sublethal exposure to OCs and Hg is analyzed and discussed.

  3. Semivolatile and volatile organic compound emissions from wood-fired hydronic heaters.

    PubMed

    Aurell, Johanna; Gullett, Brian K; Tabor, Dennis; Touati, Abderrahmane; Oudejans, Lukas

    2012-07-17

    Emissions including polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), polyaromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs), were sampled from different wood-fired hydronic heater (HH) technologies. Four commercially available HH technologies were studied: a single-stage conventional combustor with natural updraft, a three-stage downdraft combustion system, a bottom-fed pellet burner, and a two-stage heater with both a combustion and gasification chamber. The fuel consisted of three wood types (red oak, white pine, and white ash), one hardwood pellet brand, and one fuel mixture containing 95% red oak and 5% residential refuse by weight. The various HHs and fuel combinations were tested in a realistic homeowner fuel-charging scenario. Differences in emission levels were found between HH technologies and fuel types. PCDD/PCDF emissions ranged from 0.004 to 0.098 ng toxic equivalency/MJ(input) and PAHs from 0.49 to 54 mg/MJ(input). The former was increased by the presence of 5% by weight refuse. The white pine fuel had the highest PAH emission factor, while the bottom fed pellet burner had the lowest. The major VOCs emitted were benzene, acetylene, and propylene. The highest emissions of PAHs, VOCs, and PCDDs/PCDFs were observed with the conventional unit, likely due to the rapid changes in combustion conditions effected by the damper opening and closing.

  4. Persistent organic pollutants in chinook salmon (Oncorhynchus tshawytscha): implications for resident killer whales of British Columbia and adjacent waters.

    PubMed

    Cullon, Donna L; Yunker, Mark B; Alleyne, Carl; Dangerfield, Neil J; O'Neill, Sandra; Whiticar, Michael J; Ross, Peter S

    2009-01-01

    We measured persistent organic pollutant (POP) concentrations in chinook salmon (Oncorhynchus tshawytscha) in order to characterize dietary exposure in the highly contaminated, salmon-eating northeastern Pacific resident killer whales. We estimate that 97 to 99% of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dichlorodiphenyltrichloroethane (DDT), and hexachlorocyclohexane (HCH) in returning adult chinook were acquired during their time at sea. Highest POP concentrations (including PCBs, PCDDs, PCDFs, and DDT) and lowest lipids were observed in the more southerly chinook sampled. While feeding by salmon as they enter some more POP-contaminated near-shore environments inevitably contribute to their contamination, relationships observed between POP patterns and both lipid content and delta13C also suggest a migration-related metabolism and loss of the less-chlorinated PCB congeners. This has implications for killer whales, with the more PCB-contaminated salmon stocks in the south partly explaining the 4.0 to 6.6 times higher estimated daily intake for sigmaPCBs in southern resident killer whales compared to northern residents. We hypothesize that the lower lipid content of southerly chinook stocks may cause southern resident killer whales to increase their salmon consumption by as much as 50%, which would further increase their exposure to POPs.

  5. Health risk analysis of human exposures to soil amended with sewage sludge contaminated with polychlorinated dibenzodioxins and dibenzofurans

    SciTech Connect

    Eschenroeder, A.; Jaeger, R.J.; Ospital, J.J.; Doyle, C.P.

    1986-10-01

    The risk of cancer to humans exposed to soil treated with wastewater/sewage treatment plant sludge, known to be contaminated with small amounts of polychlorinated dibenzodioxins and dibenzofurans (PCDDs and PCDFs), was evaluated. The particulate-bound PCDDs and PCDFs are found in trace amounts in the effluent from ground water pumping (dewatering) at an abandoned wood preservation facility. The water, which was sent to a water recovery plant, underwent primary and secondary treatment prior to discharge. The residual sludge was added to agricultural soil as a conditioner. The present analysis treats the extreme case of sludge applied near the home of a target individual, a lifetime resident, who is also a farm worker in the area of the application. The successive stages of infancy, childhood and adulthood are treated separately to assess the contributions of typical age-specific indoor and outdoor activities on exposure rates. Five toxicity rating schemes using so-called TCDD equivalents, and two unit risk slopes are applied to the chemical profile in sludge to determine the cancer potency of the soil contaminants. These risk estimates range from 1 X 10-8 to 3 X 10-7.

  6. Forms and prevalence of intersexuality and effects of environmental contaminants on sexuality in cricket frogs (Acris crepitans).

    PubMed Central

    Reeder, A L; Foley, G L; Nichols, D K; Hansen, L G; Wikoff, B; Faeh, S; Eisold, J; Wheeler, M B; Warner, R; Murphy, J E; Beasley, V R

    1998-01-01

    Cricket frogs (Acris crepitans) from several different sites in Illinois were collected to assess the effects of environmental contamination on the prevalence of intersex gonads. Of 341 frogs collected in 1993, 1994, and 1995, 2.7% were intersex individuals. There was no statistically significant relationship between the chemical compounds detected and cricket frog intersexuality. However, there was an association approaching significance (p = 0.07) between the detection of atrazine and intersex individuals. A comparison of reference sites with sites that had point polychlorinated biphenyl (PCB) and polychlorinated dibenzofuran (PCDF) contamination revealed a significant relationship between sex-ratio reversal and contamination with PCBs and PCDFs. The sex ratio of juvenile frogs studied from three sites with PCB and PCDF point contamination favored males over females, which was the opposite of the sex ratio in control ponds (p = 0.0007). The statistically significant correlation between organochlorine contamination and sex-ratio reversal suggests PCBs and PCDFs can influence cricket frog sexual differentiation. The current study suggests that in cricket frogs, sex ratios and the prevalence of intersex gonads are altered by environmental contamination. Images Figure 1 Figure 2 PMID:9647894

  7. Environmental contaminants and reproductive success of great blue herons Ardea herodias in British Columbia, 1986-1987.

    PubMed

    Elliott, J E; Butler, R W; Norstrom, R J; Whitehead, P E

    1989-01-01

    In 1986, eggs were collected and productivity estimated at four great blue heron (Ardea herodias) colonies on the coast of British Columbia. Polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were present in all eggs in a qualitatively similar pattern among colonies. PCDD levels were significantly elevated at a colony near a kraft pulp mill at Crofton on Vancouver Island, although there was no correlation between the number of young raised in a nest and levels of either PCDDs, PCDFs, PCBs, organochlorine pesticides or mercury. In 1987, heron productivity was normal at three colonies, while the colony at Crofton failed to raise any young. A normal complement of eggs were apparently laid in about 57 nests, but during incubation they were destroyed and the broken eggshells were found in and beneath the nests. Analysis of eggs salvaged from nests showed that 2378-TCDD levels were about three times higher in 1987 than in 1986. At a colony in Vancouver, 2378-TCDF levels were significantly higher in 1987 than 1986 eggs. Levels of organochlorine pesticides and total mercury in eggs were generally low; highest residue levels were found in two mainland colonies, particularly at one adjacent to an agricultural area. Total PCB levels were low and did not differ significantly among locations. Analysis of PCB congener ratios indicated different sources of PCBs. Regurgitated prey samples collected in 1986 from four locations had generally low levels of PCDD, PCDF, mercury, lead and cadmium contamination.

  8. Homologue and isomer distribution of dioxins observed in water samples collected from Kahokugata Lagoon and inflowing rivers, Japan.

    PubMed

    Kakimoto, Hitoshi; Oka, Hideo; Miyata, Yoshiaki; Yonezawa, Yumiko; Niikawa, Akiko; Kyudo, Hirohisa; Tang, Ning; Toriba, Akira; Kizu, Ryoichi; Hayakawa, Kazuichi

    2006-06-01

    Water samples were collected at 17 sites in Kahokugata Water Basin, a closed water basin in central Japan. We determined the concentration of dioxins of the water samples. Linear relationships between toxic equivalent (TEQ) concentrations of dioxin and concentrations of suspended solid (SS) were obtained at sites in Kahokugata Lagoon and in the rivers flowing into the lagoon. Homologue composition of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) indicated that all the water samples were still strongly influenced by chlorinated herbicides, such as chloronitrofen (CNP) and pentachlorophenol (PCP) that had been widely used in rice fields. The main isomer distributions of the PCDD homologues were not significantly different among the sampling sites, while the main isomer distributions of the PCDF homologues were considerably different among the sampling sites. At a few sampling points in the downstream part of one of the rivers, high concentrations of 1,3,6,7,8-pentachloro dibenzofuran (1,3,6,7,8-PeCDF) and its related isomers (1,3,6,8-chlorine-substituted PCDFs) were traced to a dye manufacturing plant. These non-toxic isomers are usually only minor constituents in environmental water samples and are not indicators of any known dioxin sources. The dyeing discharge was found to make a contribution only in the water samples collected near the plant and the seasonal variation of the contribution might depend on the flow rate of the river.

  9. Characterization of gas and particle emissions from laboratory burns of peat

    NASA Astrophysics Data System (ADS)

    Black, Robert R.; Aurell, Johanna; Holder, Amara; George, Ingrid J.; Gullett, Brian K.; Hays, Michael D.; Geron, Chris D.; Tabor, Dennis

    2016-05-01

    Peat cores collected from two locations in eastern North Carolina (NC, USA) were burned in a laboratory facility to characterize emissions during simulated field combustion. Particle and gas samples were analyzed to quantify emission factors for particulate matter (PM2.5), organic carbon (OC), elemental carbon, light absorbing carbon, absorption Angstrom exponent, metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs). CO from the smoldering burns, up to 7 h in duration, contributed approximately 16% of the total carbon emitted. Emission factors for black carbon (BC) and light absorbing carbon (UVPM) were considerably lower than those found for forest litter burns. Emission factors for PCDDs/PCDFs were near published values for forest fuels, at 1-4 ng toxic equivalents (TEQ)/kg carbon burned (Cb). Total PAH concentrations of ≥12 mg/kg were higher than published data from biomass burns, but roughly the same in terms of toxicity. Application of these emission factors to the noteworthy 2008 "Evans Road" fire in NC indicates that PM2.5 and PCDD/PCDF emissions from this fire may have been 4-6% of the annual US inventory and 5% of the annual OC amount.

  10. Risk from exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans emitted from municipal incinerators

    SciTech Connect

    Maukerjee, D.; Cleverly, D.H.

    1987-01-01

    Incineration of wastes seems to be one of the major sources of PCDDs and PCDFs (dioxins). Their prevalence and extreme stability in the environment, bioavailability and bioaccumulation in the biota and human adipose tissues and breast milk are of much concern. 2,3,7,8-TCDD is one of the most toxic chemicals known and has been found to have teratogenic and carcinogenic activities in animals. Exposure to TCDD can result in chloracne, general weakness, drastic weight loss, hyperpigmentation of skin, hirsutism, porphyria cutanea tarda, liver damage, changes in activities of various liver enzymatic levels, abnormal lipid metabolism, abnormalities of the endocrine and immune systems, and possible teratogenic effects in humans. Moreover, chronic bioassay data indicate that TCDD is one of the most potent carcinogens known. It promotes liver and skin carcinogeneses, and is an initiator for various target organs in rodent test systems. According to the classification system of IARC, the qualitative evidence for carcinogenicity of TCDD is considered to be sufficient in animals and inadequate in humans. Consequently, TCDD has been placed in IARC's 2B category. In the absence of chronic bioassay data on other PCDDs and PCDFs, several TCDD equivalent approaches have been proposed for risk assessment on other congeners or mixtures. The paper compares the various approaches.

  11. Forms and prevalence of intersexuality and effects of environmental contaminants on sexuality in cricket frogs (Acris crepitans).

    PubMed

    Reeder, A L; Foley, G L; Nichols, D K; Hansen, L G; Wikoff, B; Faeh, S; Eisold, J; Wheeler, M B; Warner, R; Murphy, J E; Beasley, V R

    1998-05-01

    Cricket frogs (Acris crepitans) from several different sites in Illinois were collected to assess the effects of environmental contamination on the prevalence of intersex gonads. Of 341 frogs collected in 1993, 1994, and 1995, 2.7% were intersex individuals. There was no statistically significant relationship between the chemical compounds detected and cricket frog intersexuality. However, there was an association approaching significance (p = 0.07) between the detection of atrazine and intersex individuals. A comparison of reference sites with sites that had point polychlorinated biphenyl (PCB) and polychlorinated dibenzofuran (PCDF) contamination revealed a significant relationship between sex-ratio reversal and contamination with PCBs and PCDFs. The sex ratio of juvenile frogs studied from three sites with PCB and PCDF point contamination favored males over females, which was the opposite of the sex ratio in control ponds (p = 0.0007). The statistically significant correlation between organochlorine contamination and sex-ratio reversal suggests PCBs and PCDFs can influence cricket frog sexual differentiation. The current study suggests that in cricket frogs, sex ratios and the prevalence of intersex gonads are altered by environmental contamination.

  12. Dioxin-like compounds in pine needles around Tokyo Bay, Japan in 1999.

    PubMed

    Hanari, Nobuyasu; Horii, Yuichi; Okazawa, Tsuyoshi; Falandysz, Jerzy; Bochentin, Ilona; Orlikowska, Anna; Puzyn, Tomasz; Wyrzykowska, Barbara; Yamashita, Nobuyoshi

    2004-04-01

    Pine needle samples collected at ten spatially distant sites around Tokyo Bay in 1999 indicated a widespread lower troposphere pollution with ultra-trace dioxin-like compounds such as chlorodibenzo-p-dioxins (PCDDs), -furans (PCDFs), non-ortho- and mono-ortho-chlorobiphenyls (pPCBs), and -naphthalenes (PCNs). Elevated concentration of planar PCBs and the total PCNs were found at the sites which are located innermost to the Bay, suggesting the regional importance of the evaporative nature of the source of pollution by those compounds over this vast area. The concentrations and profiles for PCDDs and PCDFs remained largely uniform. An exception was the site near the town of Tateyama in the Chiba Prefecture, which is the southernmost but also relatively separate from the inner Bay. The site near Tateyama showed somehow background contamination with all compound groups and highly different profiles of PCNs. The principal component analysis (PCA) of the data matrix has revealed that around the Tokyo Bay, apart from the evaporative emission sources for PCNs and PCBs, combustion related processes also play an important role as sources of the ambient air contamination not only with PCDDs/Fs but also with chloronaphthalenes and planar chlorobiphenyls.

  13. Chlorinated dibenzo-p-dioxin and dibenzofuran residue levels in food. Final report

    SciTech Connect

    Stanley, J.S.; Bauer, K.M.

    1989-10-26

    The chemical analysis of selected foods was conducted to provide an estimate of the residue levels of PCDDs and PCDFs. The foodstuffs included saltwater fish, freshwater fish, beef, chicken, pork, bovine milk, and eggs. The foodstuffs were collected from San Francisco and Los Angeles. Emphasis was placed on the collection of foodstuffs of California origin. Individual foods collected from multiple sites within San Francisco and Los Angeles were composited for analysis of the residue levels. Detectable levels of PCDDs and PCDFs were identified in all but the egg samples that were analyzed. Overall, the freshwater fish composites were found to have the highest incidence of detectable levels. The order of highest to lowest incidence of detection follows: freshwater fish > saltwater fish > pork and chicken > beef and milk > eggs. All data were generated from a sample size of approximately 10 g of extractable fatty materials. All data are presented to reflect lipid or fat concentrations such that extrapolation with other data bases can be achieved.

  14. Dioxin and polychlorinated biphenyl analysis: automation and improvement of clean-up established by example of spices.

    PubMed

    Kleinhenz, Silvia; Jira, Wolfgang; Schwind, Karl-Heinz

    2006-04-01

    To analyze polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) and polychlorinated biphenyls (PCBs) in spices by gas chromatography-mass spectrometry, a new clean-up method had to be developed owing to the high content of essential oils in the samples. A solid-phase extraction (SPE) column with activated silica endowed with sulfuric acid and sodium hydroxide was used. Under these conditions, clean-up was achieved using at least 5-7 g of pepper and even higher amounts of other spices. The automatized clean-up comprised three additional chromatographic steps after accelerated solvent extraction (ASE) followed by gel permeation: chromatography on a florisil SPE column, extract cleaning with the above-mentioned silica SPE column and chromatography with an activated charcoal column. On the basis of this automatized clean-up, a method that is more effective, rapid, simplified and economical than the available methods for PCDD/PCDF and PCB analysis is proposed. In model studies, the average recoveries for PCDDs/PCDFs ranged between 82.6% and 105.6% and for the PCBs between 71.3% and 113.3%.

  15. Analysis of industrial contaminants in indoor air: part 1. Volatile organic compounds, carbonyl compounds, polycyclic aromatic hydrocarbons and polychlorinated biphenyls.

    PubMed

    Barro, Ruth; Regueiro, Jorge; Llompart, María; Garcia-Jares, Carmen

    2009-01-16

    This article reviews recent literature on the analysis of industrial contaminants in indoor air in the framework of the REACH project, which is mainly intended to improve protection of human health and the environment from the risks of more than 34 millions of chemical substances. Industrial pollutants that can be found in indoor air may be of very different types and origin, belonging to the volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) categories. Several compounds have been classified into the priority organic pollutants (POPs) class such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/PCDFs) and related polychlorinated compounds, and polycyclic aromatic hydrocarbons (PAHs). Many of these compounds are partially associated to the air gas phase, but also to the suspended particulate matter. Furthermore, settled dust can act as a concentrator for the less volatile pollutants and has become a matrix of great concern for indoors contamination. Main literature considered in this review are papers from the last 10 years reporting analytical developments and applications regarding VOCs, aldehydes and other carbonyls, PCBs, PCDDs, PCDFs, and PAHs in the indoor environment. Sample collection and pretreatment, analyte extraction, clean-up procedures, determination techniques, performance results, as well as compound concentrations in indoor samples, are summarized and discussed. Emergent contaminants and pesticides related to the industrial development that can be found in indoor air are reviewed in a second part in this volume.

  16. Organohalogen concentrations and feeding status in Atlantic salmon (Salmo salar L.) of the Baltic Sea during the spawning run.

    PubMed

    Vuorinen, Pekka J; Kiviranta, Hannu; Koistinen, Jaana; Pöyhönen, Outi; Ikonen, Erkki; Keinänen, Marja

    2014-01-15

    Changes in the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Baltic salmon muscle were studied during the spawning migration from the southern Baltic Sea to rivers flowing into the northern Gulf of Bothnia and during the spawning period. The aim was to obtain information to facilitate the arrangement of salmon fisheries such that the human dioxin intake is taken into account. The EC maximum allowable total toxic equivalent concentration (WHO-TEQPCDD/F+PCB) was exceeded in the muscle of the majority of the migrating salmon, except in the Baltic Proper. The fresh-weight-based concentrations of all toxicant groups in salmon tended to be the lowest in the Baltic Proper and the Northern Quark, and all toxicant concentrations, except PCDDs and PCDFs, were significantly higher in the spawning salmon than in the salmon caught during the spawning run. The fat content of the salmon muscle decreased by 60% during the spawning run, and the lipid-based total toxicant concentrations were consequently 4.2-6.2 times higher during the spawning period than during the spawning migration. However, the toxicants were concentrated just before spawning, and thus there is no essential difference related to whether the salmon are caught in the sea or the recreational river fishery.

  17. Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner.

    PubMed

    Xu, Fei; Zhang, Ruiming; Li, Yunfeng; Zhang, Qingzhu; Wang, Wenxing

    2015-01-01

    Polychlorinated naphthalenes (PCNs) are dioxins-like compounds and are formed along with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in thermal and combustion procedures. Chlorophenols (CPs) are the most important forerunners of PCNs. A comprehensive comprehension of PCN formation procedure from CPs is a precondition for reducing the discharge of PCNs. Experiments on the formation of PCNs from CPs have been hindered by PCN toxicity and short of precise detection methods for active intermediate radicals. In this work, PCN formation mechanism in gas-phase condition from 2-chlorophenol (2-CP) as forerunner was studied by quantum chemistry calculations. Numbers of energetically advantaged formation routes were proposed. The rate constants of key elementary steps were calculated over 600-1200 K using canonical variational transition-state theory (CVT) with small curvature tunneling contribution (SCT) method. This study illustrates formation of PCNs with one chlorine atom loss from 2-CP is preferred over that without chlorine atom loss. In comparison with formation of PCDFs from 2-CP, PCN products are less chlorinated and have lower formation potential.

  18. Contaminants in white sturgeon (Acipenser transmontanus) from the upper Fraser River, British Columbia, Canada

    SciTech Connect

    MacDonald, D.D.; Ikonomou, M.G.; Rantalaine, A.L.; Rogers, I.H.; Sutherland, D.; Oostdam, J. Van

    1997-03-01

    Four white sturgeon were collected from the upper Fraser River near Prince George, British Columbia, Canada, in the fall of 199a and 1992. Two additional fish were taken from the Fraser River near Williams Lake, some 250 km downstream of Prince George. Samples of white muscle, red muscle, liver, and roe were analyzed for metals, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho and mono-ortho polychlorinated biphenyls (PCBs), and chlorophenols to determine whether the tissues of this species were acceptable for human consumption. The concentrations of mercury in the white muscle and liver of several fish from the upper Fraser River exceeded the provincial tissue residue criteria for people who consumed low quantities of fish. The concentrations of PCDDs, PCDFs, and coplanar PCBs (expressed as 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents) in red muscle and liver of these fish exceeded the Health Canada working guidelines for the protection of human health. By comparison, white sturgeon collected in the lower Fraser River had much lower concentrations of metals and organic contaminants. The differences in contaminant burdens in fish from the two widely separated reaches of the river reflect their proximity to or distance from known contaminant sources.

  19. Sex differences in the accumulation of chlorinated dioxins in the cormorant (Phalacrocorax carbo): implication of hepatic sequestration in the maternal transfer.

    PubMed

    Kubota, Akira; Yoneda, Kumiko; Tanabe, Shinsuke; Iwata, Hisato

    2013-07-01

    This study focuses on gender-specific accumulation features of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in common (great) cormorants (Phalacrocorax carbo) collected from Lake Biwa, Japan. Male cormorants showed a tendency to have higher levels of PCDD/DFs and DL-PCBs than did females. For PCDDs, the male-to-female concentration ratio (M/F ratio) for each congener significantly decreased with the liver-to-muscle concentration ratio (Li/Mu ratio). For PCDFs, there also was a weak negative relationship between Li/Mu ratio and M/F ratio. In contrast, for DL-PCBs, M/F ratios showed no correlation with Li/Mu ratios, but increased with an increase in lipophilicity. These results, together with observations from prior studies, suggest that congener-specific hepatic sequestration may be a factor limiting the maternal transfer of PCDDs and, to a lesser extent, PCDFs. Maternal transfer of DL-PCBs seems to favor more lipophilic congeners in the cormorants. PMID:23597727

  20. Sources of polychlorinated dibenzothiophenes in Newark Bay estuary sediments

    SciTech Connect

    Huntley, S.L.; Wenning, R.J.; Paustenbach, D.J.; Wong, A.S.; Luksemburg, W.J.

    1994-12-31

    Polychlorinated dibenzothiophenes (PCDTS) are sulfur-containing structural analogs of polychlorinated dibenzofurans (PCDFs). Research to date indicates that PCDTs are formed by mechanisms similar to those that result in the formation of PCDFs and polychlorinated dibenzo-p-dioxins (PCDDs). PCDTs have been detected in fly ash from municipal incinerators and effluent from pulp and paper mills. Under laboratory conditions, PCDTs have been formed by thermal reaction of polychlorinated biphenyls and polychlorinated benzenes in the presence of elemental sulfur. The available data on sources of PCDTs suggests that environmental contamination is likely to be widespread. Recently, six samples collected from the lower Passaic River were reported to have a mean concentration of 3,680 ppt 2,4,6,8-tetrachlorodibenzothiophene. It has been suggested that this compound is a chemical marker for 2,4,5-trichlorophenol production. Such a relationship, however, has not been demonstrated. Several pulp and paper mills on the Passaic River, numerous municipal and industrial incinerators, manufacturers of sulfur-containing pesticides, and a nearby PCB-contaminated site are possible sources of PCDTs in the Newark Bay estuary. This study reports on the results of recent investigations to characterize the sources of 2,4,6,8-PCDT in the estuary.

  1. Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner

    PubMed Central

    Xu, Fei; Zhang, Ruiming; Li, Yunfeng; Zhang, Qingzhu; Wang, Wenxing

    2015-01-01

    Polychlorinated naphthalenes (PCNs) are dioxins-like compounds and are formed along with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in thermal and combustion procedures. Chlorophenols (CPs) are the most important forerunners of PCNs. A comprehensive comprehension of PCN formation procedure from CPs is a precondition for reducing the discharge of PCNs. Experiments on the formation of PCNs from CPs have been hindered by PCN toxicity and short of precise detection methods for active intermediate radicals. In this work, PCN formation mechanism in gas-phase condition from 2-chlorophenol (2-CP) as forerunner was studied by quantum chemistry calculations. Numbers of energetically advantaged formation routes were proposed. The rate constants of key elementary steps were calculated over 600–1200 K using canonical variational transition-state theory (CVT) with small curvature tunneling contribution (SCT) method. This study illustrates formation of PCNs with one chlorine atom loss from 2-CP is preferred over that without chlorine atom loss. In comparison with formation of PCDFs from 2-CP, PCN products are less chlorinated and have lower formation potential. PMID:26516839

  2. A source inventory and budget for chlorinated dioxins and furans in the United Kingdom environment.

    PubMed

    Harrad, S J; Jones, K C

    1992-09-11

    Polychlorinated dibenzo-p-dioxins (PCDDs) and -furans (PCDFs) are ubiquitous in the environment. This paper estimates the present UK environmental loading of PCDD/Fs in soils, vegetation, air, water and sediments. Greater than 95% of the estimated total PCDD/F loading of 5.7 t in the UK environment is present in surface soils. Annual emissions from known primary sources of PCDDs and PCDFs are estimated. The most important of these include: municipal waste incinerator stack emissions (10.9 kg sigma PCDD/F per annum); industrial (7.7 kg/year) and domestic (5.1 kg/year) combustion of coal; clinical waste incinerators (1.7 kg/year); volatilisation from chlorophenol-treated substrates (1.7 kg/year) and combustion of leaded petrol by motor vehicles (0.7 kg/year). These sources are generally easy to define and reasonably reliable national estimates can be obtained. More difficult to quantify are secondary releases from the large UK stock of pentachlorophenol (PCP) and PCP-treated products, which may represent quantitatively one of the most important sources of total PCDD/Fs to the environment. Estimates of homologue-specific emissions indicate that combustion processes represent a far more significant source of tetra and penta CDD/Fs than do chlorophenols, which in turn constitute a greater source of hepta- and octachlorinated congeners. Direct emission of PCDD/Fs into the atmosphere from combustion processes facilitates their atmospheric transport to remote locations. This, coupled with the diffuse nature of combustion processes, means that the effects of PCDD/F contamination originating from anthropogenic combustion are more widespread than those from the use and disposal of chlorophenols. Contamination from chlorophenols will be more localised, owing to the insignificance of direct atmospheric release pathways for this source. Although there is reasonable agreement between the estimated current annual flux and the present UK environmental loading of PCDDs and PCDFs, a

  3. Serum Concentrations of Selected Persistent Organic Pollutants in a Sample of Pregnant Females and Changes in Their Concentrations during Gestation

    PubMed Central

    Wang, Richard Y.; Jain, Ram B.; Wolkin, Amy F.; Rubin, Carol H.; Needham, Larry L.

    2009-01-01

    Objectives In this study we evaluated the concentrations of selected persistent organic pollutants in a sample of first-time pregnant females residing in the United States and assessed differences in these concentrations in all pregnant females during gestation. Methods We reviewed demographic and laboratory data for pregnant females participating in the National Health and Nutrition Examination Survey, including concentrations of 25 polychlorinated biphenyls (PCBs), 6 polychlorinated dibenzo-p-dioxins (PCDDs), 9 polychlorinated dibenzofurans (PCDFs), and 9 organochlorine pesticides. We report serum concentrations for first-time pregnant females (2001–2002; n = 49) and evaluate these concentrations in all pregnant females by trimester (1999–2002; n = 203) using a cross-sectional analysis. Results The chemicals with ≥ 60% detection included PCBs (congeners 126, 138/158, 153, 180), PCDDs/PCDFs [1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (1234678HpCDD), 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (123678HxCDD), 1,2,3,4,6,7,8-heptachlorodibenzofuran (1234678HpCDF), 1,1′-(2,2-dichloroethenylidene)-bis(4-chlorobenzene) (p,p′-DDE)], and trans-nonachlor. The geometric mean concentration (95% confidence intervals) for 1234678HpCDD was 15.9 pg/g lipid (5.0–50.6 pg/g); for 123678HxCDD, 9.7 pg/g (5.5–17.1 pg/g); and for 1234678HpCDF, 5.4 pg/g (3.3–8.7 pg/g). The differences in concentrations of these chemicals by trimester were better accounted for with the use of lipid-adjusted units than with whole-weight units; however, the increase in the third-trimester concentration was greater for PCDDs/PCDFs (123678HxCDD, 1234678HpCDF) than for the highest concentration of indicator PCBs (138/158, 153, 180), even after adjusting for potential confounders. Conclusion The concentrations of these persistent organic pollutants in a sample of first-time pregnant females living in the United States suggest a decline in exposures to these chemicals since their ban or restricted use

  4. Contrasting retinoid and thyroid hormone status in differentially-contaminated northern fulmar colonies from the Canadian Arctic, Svalbard and the Faroe Islands.

    PubMed

    Verreault, Jonathan; Helgason, Lisa B; Gabrielsen, Geir W; Dam, Maria; Braune, Birgit M

    2013-02-01

    The northern fulmar (Fulmarus glacialis) has previously been shown to accumulate a wide range, and occasionally high concentrations of organochlorines (OCs) (e.g., PCBs, chlorobenzenes, DDT- and chlordane-related compounds, dioxins and furans). The present study aimed to investigate, using a meta-analysis approach, the variations in cytochrome P450 (CYP) 1A-like enzyme induction based on ethoxyresorufin O-deethylase activity (EROD) and selected physiological variables (retinoids and thyroid hormones) in northern fulmar breeding in three differentially OC-exposed populations: Nunavut (Canadian Arctic), Svalbard (Norwegian Arctic) and the Faroe Islands. Substantially higher (roughly two-fold) OC levels were uncovered in the liver of this long-lived fulmarine petrel breeding in the Faroe Islands relative to Svalbard and Nunavut. Liver levels of PCDDs, PCDFs and non-ortho PCBs in Faroe Islands fulmars were amongst the highest reported thus far in any seabirds from the northern regions. Positive correlations were depicted in combined fulmars (all three populations) between hepatic EROD activity and concentrations of OCs, in which strongest associations were found for dioxin-like compound (PCDFs and PCDDs) and TEQ concentrations. Moreover, moderate to strong positive correlations were found between liver OC concentrations and plasma total thyroxin (TT(4)) levels and TT(4)/total triiodothyronine (TT(3)) level ratios, as well as strong negative correlations between the same suite of OCs and plasma TT(3) levels. Hepatic OC concentrations (PCBs, PCDDs, PCDFs, HCB, p,p'-DDE and oxychlordane) also were positively correlated with hepatic retinyl palmitate levels which, in turn, were associated with a significant decrease in plasma retinol levels and somewhat unchanged liver retinol levels. The present meta-analysis investigation on northern fulmar breeding in three geographically-distant sites illustrated that OC exposure (mainly PCBs and dioxins/furans) may be associated with

  5. Temporal trends of polychlorinated dibenzo-p-dioxins and dibenzofurans and dioxin-like polychlorinated biphenyls in mothers' milk from Sweden, 1972-2011.

    PubMed

    Fång, Johan; Nyberg, Elisabeth; Bignert, Anders; Bergman, Åke

    2013-10-01

    Temporal trends of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in mothers' milk are still quite rare. Data are particularly scarce when it comes to concentrations from the last decade, 2000 and onwards. The aims of the present study were to assess temporal trends of PCDD, PCDF and DL-PCB in mothers' milk from Stockholm, 1972-2011 and to compare the results with previous analysis of some of the older samples. The samples were analyzed by high resolution GC/MS and results were statistically evaluated for the periods, 1972-2011 and 2002-2011. The rate of which ∑PCDDs, ∑DL-PCBs and the ∑TEQ are decreasing (on pg/g fat WHO-TEQ2005) is higher in the last decade compared to the 40year period, 1972-2011. A similar trend is indicated, but not confirmed, for ∑TEQ of PCDFs, probably due to too many PCDF congeners below LOQ in the period 2002-2011. Concentrations of ∑PCDDs, ∑PCDFs, ∑DLPCBs and ∑TEQ, all expressed as pg/g fat on TEQ-WHO2005-basis, show a statistically significant decline over time, 5.8-6.8% per year, 1972-2011. The last ten years the annual declines for ∑PCDDs, ∑DL-PCBs and ∑TEQ are 9.2-11% and for ∑PCDF, 5.4%. Congener specific trend analysis, 2002-2001, of PCDDs and DL-PCBs showed the same pattern, while the PCDF congeners showed no such general trend. The results from the re-analysis showed good agreement with slightly lower ∑TEQ1998 pg/g fat concentrations in six out of seven samples and mean difference of 13% in ∑TEQ1998. The study shows that time series can be elongated from previous studies, as long as the sample population remains the same.

  6. Contrasting retinoid and thyroid hormone status in differentially-contaminated northern fulmar colonies from the Canadian Arctic, Svalbard and the Faroe Islands.

    PubMed

    Verreault, Jonathan; Helgason, Lisa B; Gabrielsen, Geir W; Dam, Maria; Braune, Birgit M

    2013-02-01

    The northern fulmar (Fulmarus glacialis) has previously been shown to accumulate a wide range, and occasionally high concentrations of organochlorines (OCs) (e.g., PCBs, chlorobenzenes, DDT- and chlordane-related compounds, dioxins and furans). The present study aimed to investigate, using a meta-analysis approach, the variations in cytochrome P450 (CYP) 1A-like enzyme induction based on ethoxyresorufin O-deethylase activity (EROD) and selected physiological variables (retinoids and thyroid hormones) in northern fulmar breeding in three differentially OC-exposed populations: Nunavut (Canadian Arctic), Svalbard (Norwegian Arctic) and the Faroe Islands. Substantially higher (roughly two-fold) OC levels were uncovered in the liver of this long-lived fulmarine petrel breeding in the Faroe Islands relative to Svalbard and Nunavut. Liver levels of PCDDs, PCDFs and non-ortho PCBs in Faroe Islands fulmars were amongst the highest reported thus far in any seabirds from the northern regions. Positive correlations were depicted in combined fulmars (all three populations) between hepatic EROD activity and concentrations of OCs, in which strongest associations were found for dioxin-like compound (PCDFs and PCDDs) and TEQ concentrations. Moreover, moderate to strong positive correlations were found between liver OC concentrations and plasma total thyroxin (TT(4)) levels and TT(4)/total triiodothyronine (TT(3)) level ratios, as well as strong negative correlations between the same suite of OCs and plasma TT(3) levels. Hepatic OC concentrations (PCBs, PCDDs, PCDFs, HCB, p,p'-DDE and oxychlordane) also were positively correlated with hepatic retinyl palmitate levels which, in turn, were associated with a significant decrease in plasma retinol levels and somewhat unchanged liver retinol levels. The present meta-analysis investigation on northern fulmar breeding in three geographically-distant sites illustrated that OC exposure (mainly PCBs and dioxins/furans) may be associated with

  7. Dioxin, furan and PCB serum levels in a South African Tswana population: comparing the polluting effects of using different cooking and heating fuels.

    PubMed

    Pieters, Rialet; Focant, Jean-François

    2014-05-01

    In South Africa, 26-50% of households use solid fuel for cooking food and heating houses. When used as fuel, wood and chlorinated waste are known sources of polychlorinated dibenzo-para-dioxins, polychlorinated dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). Here, we compare PCDD/F, dioxin-like PCB (DL-PCB), and non-DL-PCB (NDL-PCB) levels in serum of 693 Tswana individuals in the North West province, who either burn solid biofuels or have access to electricity, gas, and paraffin. This is the first South African study on dioxin levels in humans with more than 100 participants. Serum was pooled according to fuel use, as well as to confounding factors such as gender and age. Solid-phase extraction was used to remove the target analytes from serum, after which the extracts were further refined automatically using a combination of multilayer sorbents. Compound concentrations were determined by high-resolution mass spectrometry after high-resolution gas chromatography. Mean serum lipid content was determined enzymatically to be 5.91 ± 0.42 g/L. The PCDD/F and DL-PCB levels were similar to global concentrations reported for non-exposed adults. The mean of the total Toxic Equivalencies (ΣTEQ) was 6.9 ± 3.3 pg/g lipid and the mean NDL-PCB was 70.1 ± 42.8 ng/g lipid. The mean concentrations of the PCDDs, PCDFs and the corresponding World Health Organization-TEQ (WHO-TEQ) of the population using electricity, gas, and paraffin were greater than of those reliant on solid biomass (p = 0), whereas the DL-PCBs, their corresponding WHO-TEQ, and NDL-PCBs were greater for the population who use biofuels but not significantly so. The females had higher serum levels of the PCDDs (p = 0) and PCDFs (not significant) whereas the PCBs were higher for the males (p = 0). Breastfeeding women presented lower levels of all compound classes than their non-breastfeeding counterparts (p=0) and older subjects manifested greater pollutant loads than the younger generation (p = 0

  8. Contaminants in ospreys from the Pacific Northwest: I. Trends and Patterns in polychlorinated dibenzo-p-dioxins and -dibenzofurans in eggs and plasma

    USGS Publications Warehouse

    Elliott, J.E.; Machmer, M.M.; Henny, Charles J.; Wilson, L.K.; Norstrom, R.J.

    1998-01-01

    Osprey (Pandion haliaetus) eggs were collected from 1991 to 1997 at nests (na??=a??121) upstream and downstream of bleached kraft pulp mills and at reference sites in the Fraser and Columbia River drainage systems of British Columbia, Washington, and Oregon. Blood samples were collected from nestling ospreys during the 1992 breeding season on the Thompson River. Samples were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and -dibenzofurans (PCDFs). Mean concentrations of 2,3,7,8-TCDD were significantly higher in eggs collected in 1991 at downstream compared to upstream nests near pulp mills at Kamloops and Castlegar, British Columbia. There were no significant temporal trends in 2,3,7,8-TCDD, -TCDF or other measured compounds at a sample of nests monitored between 1991 and 1994 downstream of the Castlegar pulp mill, despite changes in bleaching technology (CIO2 substitution). However, by 1997 concentrations of 2,3,7,8-TCDD and -TCDF were significantly lower than previous years in nests sampled downstream at both Castlegar and Kamloops. An unusual pattern of higher chlorinated PCDDs and PCDFs was found in many of the osprey eggs collected in this study, and considerable individual variation in the pattern existed among eggs from the same site. For example, eggs from four different nests at one study area (Quesnel) on the Fraser River had concentrations of 1,2,3,4,6,7,8-HpCDD ranging from <1 to 1,100 ng/kg and OCDD from <1 to 7,000 ng/kg wet weight. Higher mean concentrations of HpCDD and OCDD were found in eggs from the Thompson River, a tributary of the Fraser, compared to the Columbia River, and concentrations were generally higher at nests upstream of pulp mills. In plasma samples, 1,2,3,4,6,7,8-HpCDD and OCDD were the main compounds detected, with no significant differences measured between samples upstream versus downstream or earlier versus later in the breeding season. Use of chlorophenolic wood preservatives by lumber processors was considered the

  9. Differential effects of two lots of aroclor 1254: congener-specific analysis and neurochemical end points.

    PubMed Central

    Kodavanti, P R; Kannan, N; Yamashita, N; Derr-Yellin, E C; Ward, T R; Burgin, D E; Tilson, H A; Birnbaum, L S

    2001-01-01

    Aroclor 1254 is a widely studied commercial polychlorinated biphenyl (PCB) mixture which, by definition, contains 54% chlorine by weight. Recent reports indicate substantial differences in the congener composition among Aroclor lots and hence their biologic effects. We designed the current study to compare the effects of two lots of Aroclor 1254 (lots 6024 and 124-191). We analyzed these two lots for PCB congeners, polychlorinated dibenzofurans (PCDFs), polychlorinated naphthalenes (PCNs), and polychlorinated dibenzodioxins (PCDDs). We used previously established techniques for analyzing intracellular Ca(2+) buffering and protein kinase C (PKC) translocation to test their biologic activity in neuronal preparations. PCB congener-specific analysis indicated that ortho and non-ortho congeners in these two lots varied in their percent contribution. Among all congeners, the percentages of non-ortho congeners (PCBs 77, 81, 126, and 169) were higher in lot 6024 (2.9% of total) than in lot 124-191 (0.02% of total). We detected no dioxins in these two lots (< 2 ppb). Although there are some differences in the congener composition, total PCNs were similar in both lots: 171 ppm in lot 6024 and 155 ppm in lot 124-191. However, total PCDFs were higher in lot 6024 (38.7 ppm) than in lot 124-191 (11.3 ppm). When we tested these two Aroclors on Ca(2+) buffering and PKC translocation in brain preparations, the effects were significantly different. Although lot 124-191 was more potent on PKC translocation than lot 6024, lot 6024 was slightly more active on Ca(2+) buffering than lot 124-191. These effects could not be attributed to the differences in the percentage of non-ortho congeners or PCDFs because they were inactive on these two parameters. The effects could not be attributed to PCNs because the levels were almost similar. The effects seen with two lots of Aroclor 1254 in neuronal cells were also not predicted based on the TCDD toxic equivalents (TEQs), although TEQs predicted

  10. Binding effect of polychlorinated compounds and environmental carcinogens on rice bran fiber.

    PubMed

    Sera, Nobuyuki; Morita, Kunimasa; Nagasoe, Masami; Tokieda, Hisako; Kitaura, Taeko; Tokiwa, Hiroshi

    2005-01-01

    To accelerate the fecal excretion of polycyclic biphenyl (PCB), polychlorinated dibenzofurans (PCDFs), polychlorinated-p-dioxines (PCDDs) and various mutagens and carcinogens, their binding effect on rice bran fiber (RBF) was investigated for nine heterocyclic amines, six nitroarenes, 4-nitroquinoline-N-oxide, benzo[a]pyrene, furylfuramide, two kinds of flavonoid compounds and formaldehyde and ascorbic acid. PCBs, PCDFs and PCDDs suspended in nonane were incubated with RBF (10 mg/ml) at 37 degrees C and after centrifugation, unbound chemicals in the supernatant were analyzed by high-performance liquid chromatography (HPLC) and gas chromatography (GC). The binding effects on RBF were enhanced more than other dietary fibers (DFs), which were tested including corn, wheat bran, spinach, Hijiki (a kind of seaweed), sweet potatoes and burdock fibers. It was found that the binding effects were related to lignin contents. Binding of 3-amino-1(or 1,4)-dimethyl-5H-pyrido[4,3-b]indole (Trp-p-1 and Trp-p-2), food-derived carcinogens and 1-nitropyrene (1-NP), suspended in methanol, to RBF occurred within 10 min of incubation at 37 degrees C at pH 5-7, and decreased below pH 4; binding of food-derived carcinogens was pH dependent. The binding effects to RBF and pulp lignin were obtained at ratio of over 90%, while corn fiber and cellulose were at ratios of 4-30%. Polycyclic aromatic compounds were related to the number of rings, showing high binding effects to chemical structures with triple rings. Binding of 1-NP and PCB to RBF was not influenced in any aerobic and anaerobic bacterial cultures. It was also found that RBF was capable of binding even conjugates containing mutagens such as glucuronides and sulfates, as well as metabolites in urine. It was suggested, therefore, that mutagens and carcinogens were available for the fecal excretion of residual chemicals and their metabolites, and also for the fecal excretion of PCBs, PCDFs and related compound residues in patients of

  11. Guiandose por la Intrincada Senda de la Educacion Especial: Una Guia para Padres y Maestros. Tercera Edicion. (Negotiating the Special Education Maze: A Guide for Parents & Teachers. Third Edition).

    ERIC Educational Resources Information Center

    Anderson, Winifred; Chitwood, Stephen; Hayden, Deidre

    Designed to assist Spanish-speaking parents and teachers in understanding special education procedures, this book describes the process for obtaining school services for children with disabilities. An introduction reviews six major provisions of the Individuals with Disabilities Education Act (IDEA) that relate to children's rights to a free,…

  12. Viajando por la Carretera de la Educacion Especial: Una Guia para los Padres para Tener un Viaje Feliz y Seguro (Traveling the Special Education Highway: A Parent's Guide to a Safe and Happy Journey).

    ERIC Educational Resources Information Center

    Santa Maria, Karen

    Designed for Spanish-speaking parents, this brochure, written in Spanish, uses a car-trip analogy to describe special education services for students with disabilities. It addresses: (1) child find; (2) initial evaluation and eligibility determination; (3) categories of students who receive special education services and related services; (4)…

  13. Less and Less for More and More. Economic Organization Booklet 1. Teacher's Edition=Menos y menos por mas y mas. Organizacion economica libro 1. Manual para El Maestro.

    ERIC Educational Resources Information Center

    California State Univ., Los Angeles. National Dissemination and Assessment Center.

    The booklet is part of a grade 10-12 social studies series produced for bilingual education. The series consists of six major thematic modules, with four to five booklets in each. The interdisciplinary modules are based on major ideas and are designed to help students understand some major human problems and make sound, responsive decisions to…

  14. Ingestion Reiterada de Cuerpos Extranos. Forma Inusual de Presentacion del Sindrome de Munchausen por Poderes (Reiterated Ingestion of Foreign Bodies. Unusual Form of Presentation of Munchausen Syndrome by Proxy).

    ERIC Educational Resources Information Center

    Terreros, I. Gomez de; And Others

    1996-01-01

    An unusual case of Munchausen syndrome by proxy is reported. A mother with a psychiatric record of behavior disorders and family dysfunction perpetrated the ingestion of foreign bodies (for example, earrings, a screw, sewing needles) on a 10-month-old infant with a history of prematurity, repeated visits to emergency rooms, and nonjustified…

  15. About to Graduate from High School? Consider Career Education Opportunities. EdSource Student/Parent Guide = Estas por graduarte de la escuela preparatoria? Considera oportunidades para seguir tu educacion de carrera. EdSource guia de estudiantes y padres

    ERIC Educational Resources Information Center

    EdSource, 2006

    2006-01-01

    Getting a sound education is important to a student's ability to make a good living in a field they will enjoy. For many students graduating from high school, that includes high quality career technical (or vocational) education tailored to a specific job. In California, such programs are available in a wide range of fields, from healthcare to the…

  16. Por Que Mami No Puede Cambiar una Goma? Tercer Modulo de una Serie para Maestros de Escuela Elemental. (Why Can't Mommy Change a Flat Tire? Third Module of a Series for Elementary School Teachers).

    ERIC Educational Resources Information Center

    Molina, Carmen Eneida, Ed.; And Others

    This guide for teachers, in English and Spanish, examines the role parents play in the socialization of sex roles. A pre-test and post test are included to measure the user's awareness of sexual stereotyping. Five object lessons cover the following topics: (1) stereotypes which exist prior to a baby's birth; (2) behavioral standards on which…

  17. Por Que Rosa No Es Valiente? Cuarto Modulo de una Serie para Maestros de Escuela Elemental (Why Isn't Rosie Brave? Fourth Module of a Series for Elementary School Teachers).

    ERIC Educational Resources Information Center

    Molina, Carmen Eneida, Ed.; And Others

    This guide in English and Spanish provides teachers with methods for identifying textbook bias and stereotyping. A pre-test and post-test designed to measure awareness of textbook stereotypes are included. Four object lessons discuss the function of repetition, cumulative effect, omission, and distortion in reinforcing stereotypes, especially…

  18. Vistazos Intimos De Puebla; Una Compilacion De Informes Individuales Preparados Por Los Participantes Del Instituto De Verano (NDEA) (Close-ups on Puebla; A Compilation of Individual Reports Prepared by the Participants of the NDEA Summer Institute).

    ERIC Educational Resources Information Center

    Wichita State Univ., KS.

    The individual and committee reports on the sociology of Puebla, Mexico, which are collected here, were written by participants in an NDEA Summer Institute program of the University of Wichita, Kansas. The underlying motives of the program, described in the preface, were to provide participants with real language experience and a chance to…

  19. Fields without Borders: An Anthology of Documentary Writing and Photography by Student Action with Farmworkers' Interns = Campos sin Fronteras: Una Antologia de Obras Escritas y Fotografia por Estudiantes Internos de Accion Estudiantil con Trabajadores Agricolas.

    ERIC Educational Resources Information Center

    Manly, Libby, Ed.; Okie, Alejandra, Ed.; Wiggins, Melinda, Ed.

    In this booklet, essays and poems, presented both in English and in Spanish, portray the feelings, conditions, and economic plight of migrant and seasonal farmworkers in North and South Carolina, often in their own words. A preface describes Student Action with Farmworkers summer internships in which college students spend 10 weeks working with…

  20. The Latinas' Guide to the Information Superhighway: A Bilingual Guide for Latinas by Latinas = Guia para Mujeres Latinas sobre la Supercarretera de la Informacion: Una Guia Bilingue para Latinas por medio de Latinas.

    ERIC Educational Resources Information Center

    MANA, A National Latina Organization, Washington, DC.

    This guide to the Internet is designed to give Latinas basic information on computers and the information superhighway. Written in both Spanish and English, the guide begins by defining the Internet and making some suggestions about acquiring access to a computer. Among the topics discussed are how to choose an Internet service provider, how to…

  1. TECNOLOGÍAS DE INFORMACIÓN Y COMUNICACIÓN PARA LA PREVENCIÓN Y CONTROL DE LA INFECCIÓN POR EL VIH Y OTRAS ITS*

    PubMed Central

    Curioso, Walter H.; Blas, Magaly M.; Kurth, Ann E.; Klausner, Jeffrey D.

    2010-01-01

    Avances tecnológicos innovadores como Internet, computadoras personales de bolsillo, teléfonos celulares y otros equipos son un arsenal en crecimiento en el esfuerzo de impedir y controlar el VIH y otras infecciones de transmisión sexual (ITS). A pesar que existe una diversidad de tecnologías de información y comunicación en diferentes etapas de desarrollo para la prevención del VIH e ITS, la investigación en esta área se encuentra aún en crecimiento, y el impacto en la incidencia de enfermedad, las evaluaciones con diseños rigurosos y los estudios económicos todavía son muy limitados. Sin embargo, algunas de estas evidencias son prometedoras y poseen un gran potencial para su uso en nuestro medio. En este artículo hemos realizado una revisión sistemática de la literatura relacionada con el uso de la tecnología aplicada a la prevención y control del VIH e ITS. De ser usada apropiadamente, esta tecnología podría mejorar la vigilancia del VIH y otras ITS, diagnóstico, notificación de parejas, prevención, manejo clínico, y capacitación de profesionales de la salud. PMID:26339254

  2. Engaging Foreign Language Learners in a Web 2.0-Mediated Collaborative Learning Process (Inclusión de estudiantes de lenguas extranjeras en procesos colaborativos de aprendizaje mediados por la web 2.0)

    ERIC Educational Resources Information Center

    Cote Parra, Gabriel Eduardo

    2015-01-01

    The purpose of this action research was to explore the types of interactions that foreign language learners experience while using a wiki as a supporting tool for a face-to-face research course. This design allowed me to play a dual role: first, I studied my own classroom setting and students. Second, I implemented a pedagogical intervention based…

  3. Encouraging Students to Enhance Their Listening Performance (Cómo animar a los estudiantes para que mejoren su desempeño en comprensión oral por sí mismos)

    ERIC Educational Resources Information Center

    Hernández-Ocampo, Sonia Patricia; Vargas, Sonia Patricia

    2013-01-01

    Spanish-speaking students constantly complain about the difficulty they have comprehending spoken English. It seems teachers do not often provide them with strategies to alleviate that. This article reports on a pedagogical experience carried out at a Colombian university to help pre-service teachers at an intermediate level of English to improve…

  4. John Tracy Clinic: Programa de Ensenanza por Correspondencia para Los Padres de Ninos Sordo-Ciegos de Edad Preescolar (John Tracy Clinic Correspondence Learning Program for Parents of Preschool Deaf-Blind Children).

    ERIC Educational Resources Information Center

    Thielman, Virginia B.; And Others

    Written in Spanish, the document contains a correspondence learning program for parents of deaf blind preschoolers. An introductory section gives preliminary instructions, an introduction to sign language, and a list of resources for deaf blind children. Twelve lessons follow with information on: the parent's role in teaching the child, visual…

  5. VISIÓN GENERAL DE LA EVALUACIÓN DEL RIESGO EN SALUD INFANTIL EMPLEANDO UN ENFOQUE POR ETAPAS DE DESARROLLO (American translation is: Overview of a Life Stage Approach to Children's Health Risk Assessment)

    EPA Science Inventory

    Discussing the challenges associated with estimating and interpreting toxicant exposures and health risks from biomonitoring data. This extended abstract was translated in Spanish and published in Acta Toxicologica Argentina.

  6. Crystal structure of bis-(4-nitro-aniline-κN (1))(5,10,15,20-tetra-phenyl-por-phy-rin-ato-κ(4) N)cobalt(III) chloride di-chloro-methane monosolvate.

    PubMed

    Belghith, Yassine; Mansour, Anissa; Nasri, Habib

    2014-09-01

    The reaction of [Co(III)(TPP)Cl] (TPP is the dianion of 5,10,15,20-tetra-phenyl-porphyrin) with an excess of 4-nitro-aniline in di-chloro-methane leads to the title compound, [Co(III)(C44H28N4)(C6H6N2O2)2]Cl·CH2Cl2. The Co(III) ion lies on an inversion centre and is octa-hedrally coordinated by two N atoms of the NH2 groups of the two 4-nitro-aniline trans-axial ligands and four pyrrole N atoms of the porphyrin. The asymmetric unit contains one half of the [Co(III)(TPP)(4-nitro-aniline)2](+) ion complex, one chloride counter-ion (lying on a twofold rotation axis) and one half di-chloro-methane solvent mol-ecule, where the C atom lies on a twofold rotation axis. The average equatorial Co-N(pyrrole) distance (Co-Np) is 1.982 (2) Å and the axial Co-N(4-nitro-aniline) bond length is 2.006 (2) Å. The crystal packing is stabilized by an N-H⋯Cl hydrogen bond between the N atom of the amino group of the 4-nitro-aniline axial ligand and the chloride counter-ion. The supra-molecular architecture is further stabilized by weak C-H⋯π inter-actions. PMID:25309176

  7. Trans --> cis isomerization of trans-[(dppm)2Ru(H)(L)][BF4] (L = P(OR)3) complexes: preparation of cis-[(dppm)2Ru(eta2-H2)(L)][BF4]2.

    PubMed

    Mathew, Nisha; Jagirdar, Balaji R; Ranganathan, Anupama

    2003-01-13

    A series of new dicationic dihydrogen complexes of ruthenium of the type cis-[(dppm)(2)Ru(eta(2)-H(2))(L)][BF(4)](2) (dppm = Ph(2)PCH(2)PPh(2); L = P(OMe)(3), P(OEt)(3), PF(O(i)Pr)(2)) have been prepared by protonating the precursor hydride complexes cis-[(dppm)(2)Ru(H)(L)][BF(4)] (L = P(OMe)(3), P(OEt)(3), P(O(i)Pr)(3)) using HBF(4).Et(2)O. The cis-[(dppm)(2)Ru(H)(L)][BF(4)] complexes were obtained from the trans hydrides via an isomerization reaction that is acid-accelerated. This isomerization reaction gives mixtures of cis and trans hydride complexes, the ratios of which depend on the cone angles of the phosphite ligands: the greater the cone angle, the greater is the amount of the cis isomer. The eta(2)-H(2) ligand in the dihydrogen complexes is labile, and the loss of H(2) was found to be reversible. The protonation reactions of the starting hydrides with trans PMe(3) or PMe(2)Ph yield mixtures of the cis and the trans hydride complexes; further addition of the acid, however, give trans-[(dppm)(2)Ru(BF(4))Cl]. The roles of the bite angles of the dppm ligand as well as the steric and the electronic properties of the monodentate phosphorus ligands in this series of complexes are discussed. X-ray crystal structures of trans-[(dppm)(2)Ru(H)(P(OMe)(3))][BF(4)], cis-[(dppm)(2)Ru(H)(P(OMe)(3))][BF(4)], and cis-[(dppm)(2)Ru(H)(P(O(i)Pr)(3))][BF(4)] complexes have been determined. PMID:12513094

  8. Endocrine-Disrupting Chemicals: Some Actions of POPs on Female Reproduction

    PubMed Central

    Gregoraszczuk, Ewa L.; Ptak, Anna

    2013-01-01

    Persistent organic pollutants (POPs), such as polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and polybrominated ethers (PBDEs), chloronaftalens (PCNs), and bisphenol A (BPA), are stable, lipophilic pollutants that affect fertility and cause serious reproductive problems, including ovotoxic action, lack of ovulation, premature ovarian failure (POF), or polycystic ovarian syndrome (PCOS). Most of the representatives of POPs influence the activation of transcription factors, not only activation of aromatic hydrocarbon receptor (AhR), but also the steroid hormone receptors. This minireview will focus on a variety of PAH activities in oocyte, ovary, placenta, and mammary gland. The complexity and diversity of factors belonging to POPs and disorders of the reproductive function of women indicate that the impact of environmental pollution as an important determinant factor in fertility should not be minimize. PMID:23762054

  9. Correlation of octanol/water partition coefficients and total molecular surface area for highly hydrophobic aromatic compounds

    SciTech Connect

    Doucette, W.J.; Andren, A.W.

    1987-08-01

    The relationship between the calculated total molecular surface area (TSA) and the octanolwater partition coefficient (K/sub ow/) is examined for a set of 32 highly hydrophobic aromatic compounds including several polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), polychlorinated dioxins (PCDDs), and polychlorinated furans (PCDFs). A generator column technique was used to experimentally measure log K/sub ow/ for each compound in order to provide an accurate, self-consistent set of values. A correlative method is presented that can be used to estimate log K/sub ow/ values from TSA within 14% for halogenated biphenyls, furans, and dioxins ranging from 3.89 to 8.58 in log K/sub ow/.

  10. Multivariate statistical approach to a data set of dioxin and furan contaminations in human milk

    SciTech Connect

    Lindstrom, G.U.M.; Sjostrom, M.; Swanson, S.E. ); Furst, P.; Kruger, C.; Meemken, H.A.; Groebel, W. )

    1988-05-01

    The levels of chlorinated dibenzodioxins, PCDDs, and dibenzofurans, PCDFs, in human milk have been of great concern after the discovery of the toxic 2,3,7,8-substituted isomers in milk of European origin. As knowledge of environmental contamination of human breast milk increases, questions will continue to be asked about possible risks from breast feeding. Before any recommendations can be made, there must be knowledge of contaminant levels in mothers' breast milk. Researchers have measured PCB and 17 different dioxins and furans in human breast milk samples. To date the data has only been analyzed by univariate and bivariate statistical methods. However to extract as much information as possible from this data set, multivariate statistical methods must be used. Here the authors present a multivariate analysis where the relationships between the polychlorinated compounds and the personalia of the mothers have been studied. For the data analysis partial least squares (PLS) modelling has been used.

  11. Levels of dioxins and dioxin-like PCBs in food samples on the Greek market.

    PubMed

    Papadopoulos, Athanasios; Vassiliadou, Irene; Costopoulou, Danae; Papanicolaou, Christina; Leondiadis, Leondios

    2004-11-01

    Food intake is the main source of exposure to dioxin-like compounds for humans. The results of a surveillance programme on polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and co-planar polychlorinated biphenyls (co-PCBs) in 77 food samples from the Greek market and producers are presented. The study included the analyses of milk and dairy products, meat and meat products, fish, vegetable oil, eggs, fruit, vegetable and rice collected between August and December 2002. After extraction, extracts were cleaned up on a series of carbon column chromatography, silica gel, alumina chromatography, and then analysed by high resolution gas chromatography/high resolution mass spectrometry. All samples had a dioxin content far below the EC Regulation (2375/2001/EC) limits. PMID:15331268

  12. Analysis of breast milk to assess exposure to chlorinated contaminants in Kazakstan: high levels of 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) in agricultural villages of southern Kazakstan.

    PubMed Central

    Hooper, K; Petreas, M X; Chuvakova, T; Kazbekova, G; Druz, N; Seminova, G; Sharmanov, T; Hayward, D; She, J; Visita, P; Winkler, J; McKinney, M; Wade, T J; Grassman, J; Stephens, R D

    1998-01-01

    To assess levels of chlorinated contaminants in breast milk, we measured organochlorine pesticides, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in breast milk samples collected in 1994 according to the World Health Organization protocol from 92 donors that were representative of regional populations in southern Kazakstan. High levels (10-120 pg/g fat) of 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic of the PCDD/PCDF congeners, were found in breast milk samples from an agricultural region. TCDD was the major contributor (75%) to the international toxicity equivalents of these samples. The same distinctive PCDD/PCDF congener pattern was found in 15 breast milk samples and 4 serum samples collected in 1996 in a follow-up study, and has now been confirmed by three analytical laboratories. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:9831540

  13. Comparison of organochlorine contaminants among sea otter (Enhydra lutris) populations in California and Alaska

    SciTech Connect

    Bacon, C.E.; Jarman, W.M.; Estes, J.A.; Simon, M.; Norstrom, R.J.

    1999-03-01

    Organochlorine pesticides, polychlorinated biphenyls (PCBs) including non-ortho PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) were measured in sea otter liver tissue from California, southeast Alaska, and the western Aleutian archipelago collected between 1988 and 1992. Average total dichlorodiphenyltrichloroethane concentrations for California otters were over 20 times higher than in Aleutian otters and over 800 times higher than otters from southeast Alaska. Levels for total PCBs in Aleutian otters were 1.7 times higher than levels in California otters and 38 times higher than otters from southeast Alaska. Levels for PCDD and PCDF were extremely low in all otter populations. Levels of PCBs in Aleutian and Californian otters are abnormally high when compared with southeast Alaskan otters. The source of PCBs to the Aleutian Islands remains unclear and vital to understanding the potential impacts to sea otters.

  14. Chlorinated and brominated dioxins and dibenzofurans in human tissue following exposure.

    PubMed Central

    Schecter, A; Ryan, J J; Masuda, Y; Brandt-Rauf, P; Constable, J; Hoang, D C; Le, C D; Hoang, T Q; Nguyen, T N; Pham, H P

    1994-01-01

    With substantial improvements in analytic techniques over the past decade, it has become possible to measure polychlorinated dioxins (PCDDs) and dibenzofurans (PCDFs) in human tissue in a congener-specific fashion down to the low parts per trillion level. This paper reviews findings using these new techniques from a number of recent medical and environmental case studies. These studies include those of workers exposed to a polychlorinated biphenyl (PCB) transformer fire in the United States, German chemical workers exposed to 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD) while cleaning up after an explosion, workers at a municipal incinerator in New York City, a chemist exposed to brominated and chlorinated dioxins, U.S. veterans and also Vietnamese civilians exposed to Agent Orange contaminated with TCDD in Vietnam, and victims of the polychlorinated dibenzofuran and PCB contaminated rice oil (Yusho) incident in Japan. PMID:8187703

  15. Organochlorine contaminants in common tern (Sterna hirundo) eggs and young from the river Rhine area (France)

    SciTech Connect

    Castillo, L. ); Thybaud, E. ); Caquet, T.; Ramade, F. )

    1994-11-01

    Common terns (Sterna hirundo) exhibit a remarkable range of variation in reproductive success. Several factors are known to contribute to reproductive failure either before hatching or between the time of hatching and fledging : predation pressure, food availability, flooding, competition for nesting sites, and toxic chemicals. Contaminants such as organochlorine pesticides, polychlorinated biphenyls (PCBs), polychlorodibenzodioxins (PCDDs), polychlorodibenzofurans (PCDFs), mercury and selenium were proved to significantly impair tern reproduction. During the reproductive period of 1988, an important mortality of common terns was observed in french colonies around the river Rhine. Approximately 50% of the young died a few days after hatching. The objective of the present study was to determine whether the intoxication by chlorinated compounds could have been responsible for the observed reproductive failure. 25 refs., 1 tab.

  16. An analysis of dioxin production as a function of chlorine feed

    SciTech Connect

    Liberson, G.L.; Belanger, W.D.

    1996-12-31

    The effectiveness of decreasing dioxin emissions by reducing incinerator chlorine feeds is the subject of a continuing debate. This paper presents an analysis of the relationship between PCDD/PCDF emissions and chlorine feed at a single hazardous waste incinerator. The data used in this analysis were taken from multiple test series, conducted over a 13 month period, at a hazardous waste incinerator that employs an activated carbon injection system for supplemental control of PCDD/PCDFs. The chlorine feed rates range between 0 and 3,304 pounds per hour, and the PCDD/PCDF emission rates range between 0.7 and 39.0 ng/DSCM {at} 7% O{sub 2}. This analysis reveals that, for a modern hazardous waste incinerator using carbon injection, there is no correlation between dioxin emissions and chlorine feed.

  17. [Measurement of chemical agents in metallurgy field: electric steel plant].

    PubMed

    Cottica, D; Grignani, E; Ghitti, R; Festa, D; Apostoli, P

    2012-01-01

    The steel industry maintains its important position in the context of the Italian production involving thousands of workers. The iron and steel processes are divided into primary steel industry, production of intermediate minerals, and secondary steel, scrap from the production of semi-finished industrial and consumer sector (metal inserted into components and metal used for dissipative uses, primarily coatings) and industrial waste. The paper presents the results of environmental monitoring carried out in some electric steel plant for the measurement of airborne chemicals that characterize the occupational exposure of workers employed in particular area like electric oven, to treatment outside the furnace, continuous casting area. For the sampling of the pollutants were used both personal and in fixed positions samplers. The pollutants measured are those typical of steel processes inhalable dust, metals, respirable dust, crystalline silica, but also Polycyclic Aromatic Hydrocarbons (PAH), polychlorinated dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).

  18. Toxic potential of non-ortho and mono-ortho coplanar PCBs in commercial PCB preparations: 2,3,7,8-T/sub 4/ CDD Toxicity Equivalence Factors Approach

    SciTech Connect

    Kannan, N.; Tanabe, S.; Tatsukawa, R.

    1988-08-01

    Identification of highly toxic polychlorinated dibenzofurans (PCDFs) in commercial PCBs has contributed to the belief that they play a major role in the PCB toxicity. However, Quantitative Structure Activity Relationship (QSAR) studies have indicated that PCB congeners with chlorine substitution at both para and two or more meta positions resemble 2,3,7,8-tetrachlorodibenzo-p-dioxin (T/sub 4/CDD) in their biologic and toxic effects due to their coplanarity. The relative toxic potential of these PCB isomers in wild animals such as Forster's tern, marine mammals and Snapping turtle has been emphasized. Some members of these toxic congeners were also identified and quantitated in commercial PCBs. However, there is no serious effort to evaluate the toxic potential of these PCB congeners in commercial PCB mixtures. Hence an isomer-specific toxic evaluation was attempted in those mixtures to understand the chemical factors behind their toxicity.

  19. Persistent organic pollutants in human breast milk from Asian countries.

    PubMed

    Tanabe, Shinsuke; Kunisue, Tatsuya

    2007-03-01

    In this paper, we concisely reviewed the contamination of persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) in human breast milk collected from Asian countries such as Japan, China, Philippines, Vietnam, Cambodia, India, Malaysia, and Indonesia during 1999-2003. Dioxins, PCBs, CHLs in Japanese, and DDTs in Vietnamese, Chinese, Cambodian, Malaysian, and HCHs in Chinese, Indian, and HCB in Chinese breast milk were predominant. In India, levels of dioxins and related compounds (DRCs) in the mothers living around the open dumping site were notably higher than those from the reference site and other Asian developing countries, indicating that significant pollution sources of DRCs are present in the dumping site of India and the residents there have been exposed to relatively higher levels of these contaminants possibly via bovine milk. PMID:16949712

  20. Environmental contamination and developmental abnormalities in eggs and hatchlings of the common snapping turtle (Chelydra serpentina serpentina) from the Great Lakes-St Lawrence River basin (1989-1991).

    PubMed

    Bishop, C A; Ng, P; Pettit, K E; Kennedy, S W; Stegeman, J J; Norstrom, R J; Brooks, R J

    1998-01-01

    During 1989-1991, we assessed developmental abnormalities in embryos and hatchlings from eggs of the common snapping turtle (Chelydra serpentina serpentina). Eggs were collected and artificially incubated from eight sites in Ontario, Canada and Akwesasne/New York, USA. In eggs from the same clutches we measured 20 organochlorine pesticides, 48 polychlorinated biphenyl (PCBs) congeners including 6 non-ortho PCBs, 8 polychlorinated dibenzodioxins (PCDDs), 14 polychlorinated dibenzofurans (PCDFs) and total mercury. We found a significant increase in abnormal development with increasing polychlorinated aromatic hydrocarbon exposure in eggs, particularly PCDD and PCDF concentrations. In contrast, the risk of abnormality was not significantly higher as toxic equivalent concentrations increased in eggs. We also found significant 7-ethoxyresorufin O-deethylase and Cytochrome P4501A responses in livers of hatchling turtles from Lake Ontario relative to hatchlings from a clean, inland site whereas we did not find any evidence of porphyria in the hatchlings from either site. PMID:15093107

  1. Human exposure to dioxin from combustion sources

    SciTech Connect

    Hattemer-Frey, H.A.; Travis, C.C.

    1988-01-01

    Because of their extreme toxicity, much concern and debate has arisen about the nature and extent of human exposure to dioxin. Since municipal solid waste (MSW) incinerators are known to emit polychorinated dibenzo-p-dioxins (PCDDs) and polycholorinated dibenzofurnas (PCDFs) many people who live near MSW incinerators fear that they will be exposed to high levels of dioxin and subsequently develop cancer. What is often overlooked in this debate, however, is the fact that the general population is continuously being exposed to trace amounts of dioxin as exemplified by the fact that virtually all human adipose tissue samples contain dioxin at levels of 3 parts per trillion (ppt) or greater. This paper provides a perspective on MSW incineration as a source of human exposure to dioxin by comparing this exposure source with exposure to background environmental contamination and evaluates some of the potential key sources of PCDD/PCDF input into the enviroment. 32 refs., 3 tabs.

  2. Chlorine-Free Red-Burning Pyrotechnics.

    PubMed

    Sabatini, Jesse J; Koch, Ernst-Christian; Poret, Jay C; Moretti, Jared D; Harbol, Seth M

    2015-09-01

    The development of a red, chlorine-free pyrotechnic illuminant of high luminosity and spectral purity was investigated. Red-light emission based solely on transient SrOH(g) has been achieved by using either 5-amino-1H-tetrazole or hexamine to deoxidize the combustion flame of a Mg/Sr(NO3 )2 /Epon-binder composition and reduce the amount of both condensed and gaseous SrO, which emits undesirable orange-red light. The new formulations were found to possess high thermal onset temperatures. Avoiding chlorine in these formulations eliminates the risk of the formation of PCBs, PCDDs, and PCDFs. This finding, hence, will have a great impact on both military pyrotechnics and commercial firework sectors.

  3. Pyrolysis products of PCBs.

    PubMed Central

    Paasivirta, J; Herzschuh, R; Humppi, T; Kantolahti, E; Knuutinen, J; Lahtiperä, M; Laitinen, R; Salovaara, J; Tarhanen, J; Virkki, L

    1985-01-01

    Model compound studies which were previously done for impurities and environmental residues of chlorophenols and for wastes of chlorination processes were extended to the impurities and pyrolysis products of polychlorinated biphenyls (PCBs). Model compounds were commercial products or synthesized and their structures proven by spectroscopic methods. These models were used as analytical reference substances in GC/ECD and GC/MS studies of the pyrolyzed PCB samples. In addition to previously known neutral components like polychlorinated dibenzofurans (PCDFs), chlorophenolic substances, especially polychlorophenols (PCPs) and polychlorinated biphenylols (PCB-OHs) were observed as major pyrolysis products of PCBs. Capacitor fires are suggested to produce in many cases chlorophenols which are major toxic hazards to people. PMID:3928353

  4. Environmental contaminants in nonviable eggs of the endangered Mississippi Sandhill Crane (Grus canadensis pulla)

    USGS Publications Warehouse

    White, D.H.; Rice, C.P.; Hoffman, D.J.; Gee, G.F.

    1994-01-01

    Our objectives were to determine if concentrations of environmental pollutants and microbial contamination in nonviable eggs of the endangered Mississippi sandhill crane (Grus canadensis pulla) contributed to egg failure. Six eggs collected in 1990 and four in 1991 contained only background levels of organochlorine pesticides and polychlorinated biphenyls (PCBs), and tests for microbial contamination were all negative. Two eggs contained late dead embryos, but neither revealed obvious abnormalities. Three eggs contained potentially harmful concentrations (23, 39, 146 pg/g, wet mass) of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), based on 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ) for combined compounds. Because of the scarcity of material suitable for laboratory examination and the endangered status of the crane, we recommend that nonviable eggs continue to be monitored for toxic pollutants.

  5. In-field measurements of PCDF emissions from coal combustion and their quantitative analyses

    SciTech Connect

    Pehlivan, M.; Beduk, D.; Pehlivan, E.

    2008-07-01

    In this study, a series of polychlorinated dibenzofurans (PCDFs) emitted to the surrounding soil as the result of the combustion of coal and wood from the industrial steam boilers and household stoves have been identified. Levels of polychlorinated dibenzofurans (PCDF) in soil samples were measured at different sites in proximity to the municipal solid waste incinerator (MSWI) to determine baseline contamination and the contributory role of incinerator emissions. PCDF contaminants were concentrated from soil samples and isolated from other materials by chromatographic methods. PCDF isomers were identified separately by column chromatography utilizing column packed with materials such as Kieselgel/44 vol% H{sub 2}SO{sub 4}, Macro Alumina B Super 1, Mix. Column, Bio Beads S-X3 Gel Chromatography, Min Alumina B Super 1 + Kieselgel/AgNO{sub 3} and their quantitative determinations were performed by GC/MS (gas chromatography/mass spectroscopy). The PCDF levels were subsequently compared with established values from previous studies.

  6. Landfill mining from a deposit of the chlorine/organochlorine industry as source of dioxin contamination of animal feed and assessment of the responsible processes.

    PubMed

    Torres, João Paulo Machado; Leite, Claudio; Krauss, Thomas; Weber, Roland

    2013-04-01

    In 1997, the Polychlorinated dibenzo-para-dioxin (PCDD)/Polychlorinated dibenzofuran (PCDF) concentrations in dairy products in Germany and other European countries increased. The PCDD/PCDF source was contaminated lime used in Brazilian citrus pulp pellets. The contaminated lime was mined from an industrial dump site. However, the detailed origin of the PCDD/PCDFs in the lime was not revealed. This paper investigates the contamination origin and describes the link between lime milk from the dumpsite of a chlorine/organochlorine industry and the contaminated lime. The contaminated lime stem from mining at the corporate landfill of Solvay Indupa in Sao Paulo. The landfill was used for 40 years for deposition of production residues and closed in 1996. The factory operated/operates at least two processes with potentially high PCDD/PCDFs releases namely the oxychlorination process for production of ethylene dichloride (EDC) and the chlor-alkali process. The main landfilled waste was lime milk (1.4 million tons) from the vinyl chloride monomer production (via the acetylene process) along with residues from other processes. The PCDD/PCDF fingerprint revealed that most samples from the chemical landfill showed an EDC PCDD/PCDF pattern with a characteristic octachlorodibenzofuran dominance. The PCDD/PCDF pattern of a Rio Grande sediment samples downstream the facility showed a chlor-alkali pattern with a minor impact of the EDC pattern. The case highlights that PCDD/PCDF- and persistent organic pollutants-contaminated sites need to be identified in a comprehensive manner as required by the Stockholm Convention (article 6) and controlled for their impact on the environment and human health. Landfill mining and reuse of materials from contaminated deposits should be prohibited. PMID:22828923

  7. Environmental contaminants in male river otters from Oregon and Washington, USA, 1994-1999

    USGS Publications Warehouse

    Grove, R.A.; Henny, C.J.

    2008-01-01

    This study reports hepatic concentrations and distribution patterns of select metals, organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in 180 male river otters (Lontra canadensis) collected from Oregon and Washington, 1994-1999. Seven regional locations of western Oregon and Washington were delineated based on associations with major population centers, industry or agriculture. Cadmium (Cd) was not found above 0.5 ??g g-1, dry weight (dw) in juveniles, but increased with age in adults though concentrations were generally low (nd-1.18 ??g g-1, dw). Regional geometric means for total mercury (THg) ranged from 3.63 to 8.05 ??g g-1, dw in juveniles and 3.46-2.6 ??g g-1 (dw) in adults. The highest THg concentration was 148 ??g g-1, dw from an apparently healthy adult male from the Olympic Peninsula of Washington. Although THg increased with age in adult otters, the occurrence of the more toxic form methylmercury (MeHg) was not evaluated. Mean OC and PCB concentrations reported in this study declined dramatically from those reported in 1978-1979 from the lower Columbia River. Organochlorine pesticide and metabolite means for both juvenile and adult river otter males were all below 100 ??g kg-1, wet weight (ww), with only DDE, DDD and HCB having individual concentrations exceeding 500 ??g kg-1, ww. Mean ??PCB concentrations in both juvenile and adult male otters were below 1 ??g g-1 for all regional locations. Mean juvenile and adult concentrations of non-ortho substituted PCBs, PCDDs and PCDFs were in the low ng kg-1 for all locations studied. ?? Springer Science+Business Media B.V. 2007.

  8. Chemical contaminants in fish feeds used in federal salmonid hatcheries in the USA

    USGS Publications Warehouse

    Maule, A.G.; Gannam, A.L.; Davis, J.W.

    2007-01-01

    Recent studies have demonstrated that fish feeds contain significant concentrations of contaminants, many of which can bioaccumulate and bioconcentrate in fish. Organochlorine (OC) contaminants are present in the fish oils and fish meals used in feed manufacture, and some researchers speculate that all fish feeds contain measurable levels of some contaminants. To determine the concentration of contaminants in feeds used in US Fish and Wildlife Service's National Fish Hatcheries, we systematically collected samples of feed from 11 cold-water fish hatcheries. All samples (collected from October 2001 to October 2003) contained at least one polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), polychlorinated biphenyl (PCB) congener, or dichlorodiphenyltrichloroethane (DDT) metabolite. Of the 55 samples in which they were analyzed 39 contained PCDDs, 24 contained PCDFs and 24 contained DDT or its metabolites. There were 10- to 150-fold differences in concentrations of total PCBs, PCDDs, PCDFs and DDT. Although PCBs were the most commonly detected contaminant in our study, concentrations (range: 0.07-10.46 ng g-1 wet weight) were low compared to those reported previously. In general, we also found lower levels of OCs than reported previously in fish feed. Perhaps most notable was the near absence of OC pesticides - except for DDT or its metabolites, and two samples containing hexachlorocyclohexane (HCH). While contaminant concentrations were generally low, the ecological impacts can not be determined without a measure of the bioaccumulation of these compounds in the fish and the fate of these compounds after the fish are released. ?? 2006 Elsevier Ltd. All rights reserved.

  9. Characteristics of the abundance of polychlorinated dibenzo-p-dioxin and dibenzofurans, and dioxin-like polychlorinated biphenyls in sediment samples from selected Asian regions in Can Gio, Southern Vietnam and Osaka, Japan.

    PubMed

    Kishida, Masao; Imamura, Kiyoshi; Takenaka, Norimichi; Maeda, Yasuaki; Viet, Pham Hung; Kondo, Akira; Bandow, Hiroshi

    2010-01-01

    The levels of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) were determined in sediment samples from Can Gio, South Vietnam, and Osaka, Japan. Can Gio is known for the defoliation of its mangrove forests by aerial spraying with Agent Orange during the Vietnam War, whereas Osaka is renowned for a PCDD/PCDF pollution accident at a municipal solid-waste incinerator. For comparison, we also analyzed PCDD/PCDFs and DL-PCBs in sediment samples from Hue and Hanoi, Vietnam. The toxic equivalent quantity (TEQ) values in Can Gio were as high as those in Hue, Hanoi, and suburban areas of Osaka, but much lower than those in urban areas of Osaka. The proportion of the World Health Organization (WHO)-TEQ value contributed by 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) in Can Gio was approximately 30%, higher than the values in the other sample areas. These data suggest that residual sedimentary TCDD that originated from aerial spraying of Agent Orange occur in only low concentrations in Can Gio. The main contributors to WHO-TEQ values in Can Gio are natural sources, as in Hue. In contrast, commercial PCBs are the dominant contributors to WHO-TEQ values in Hanoi. In Osaka, agrochemicals used in rice cultivation, the incineration of solid waste, and commercial PCBs equally contributed to WHO-TEQ values at suburban locations. The dumping of incinerator-related materials and/or the inadequate management of commercial PCBs have resulted in significantly elevated WHO-TEQ values of 240-370 ng kg(-1)dw at urban locations in Osaka.

  10. The effects of fuel composition and ammonium sulfate addition on PCDD, PCDF, PCN and PCB concentrations during the combustion of biomass and paper production residuals.

    PubMed

    Lundin, Lisa; Jansson, Stina

    2014-01-01

    The use of waste wood as an energy carrier has increased during the last decade. However, the higher levels of alkali metals and chlorine in waste wood compared to virgin biomass can promote the formation of deposits and organic pollutants. Here, the effect of fuel composition and the inhibitory effects of ammonium sulfate, (NH4)2SO4, on the concentrations of persistent organic pollutants (POPs) in the flue gas of a lab-scale combustor was investigated. Ammonium sulfate is often used as a corrosion-preventing additive and may also inhibit formation of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). In addition to PCDDs and PCDFs, polychlorinated naphthalenes (PCN) and biphenyls (PCB) were also analyzed. It was found that the flue gas composition changed dramatically when (NH4)2SO4 was added: CO, SO2, and NH3 levels increased, while those of HCl decreased to almost zero. However, the additive's effects on POP formation were less pronounced. When (NH4)2SO4 was added to give an S:Cl ratio of 3, only the PCDF concentration was reduced, indicating that this ratio was not sufficient to achieve a general reduction in POP emissions. Conversely, at an S:Cl ratio of 6, significant reductions in the WHO-TEQ value and the PCDD and PCDF contents of the flue gas were observed. The effect on the PCDF concentration was especially pronounced. PCN formation seemed to be promoted by the elevated CO concentrations caused by adding (NH4)2SO4.

  11. Multivariant statistical analysis of PCDD/FS in sewage sludges from different areas of the Valencian Community (Spain).

    PubMed

    Fuentes, M Jesús; Font, Rafael; Gómez-Rico, M Francisca; Moltó, Julia

    2007-04-01

    The levels of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in 31 sewage sludges from different wastewater treatment plants corresponding to rural, urban and industrial areas in the Valencian Community (Spain) were analysed. Values of 5.1-346.2 ng I-TEQ kg(-1) (dry weight) were detected for sewage sludge with the highest value in one sample from an industrial area. Therefore the majority of the samples did not exceed the limit proposed (100 ng I-TEQ kg(-1)) by the [EU, 2000. Working document on sludge, 3rd draft. Brussels. Available from: http://europa.eu.int/comm/environment/waste/sludge/sludge_en.pdf] for use in agriculture. The dominant congeners for each family of compounds were 1,2,3,4,6,7,8-HpCDD and OCDD from PCDDs, and 1,2,3,4,6,7,8-HpCDF and OCDF from PCDFs. The total concentrations of PCDD/Fs were evaluated statistically through SPPS 11.0 for Windows. The principal component analysis (PCA) was used to extract two PCs as a linear combination of the original variables, one of them associated to urban+highly industrial areas and the other one to urban+low industrial areas. The linear regression method was applied and an efficient correlation was obtained between the total I-TEQ values for each sample and two of most abundant congeners (OCDF and OCDD). This expression was obtained with the results of the 31 samples analysed and a variety of data from other authors. Furthermore, several bilateral correlations between the different congeners completed the statistical analysis.

  12. Polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in fishes from Saginaw Bay, Michigan

    SciTech Connect

    Giesy, J.P.; Tillitt, D.E.; Jude, D.J.

    1997-04-01

    Concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated naphthalenes (PCNs), polychlorinated dibenzothiophenes (PCDTs), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) equivalents were measured in composite samples of forage fishes and several sizes of walleyes (Stizostedion vitreum) and common carp (Cyprinus carpio) collected from Saginaw Bay, Michigan, USA. The concentrations of 2,3,7,8-TCDD equivalents determined from the use of TCDD equivalency factors (TEFs) and instrumentally determined concentrations of individual congeners were designated TEq. The 2,3,7,8-TCDD equivalents determined on the same extracts with the H4IIE bioassay were defined as TCDD-EQ. Concentrations of TCDD-EQ and TEq were significantly, but poorly correlated (R{sup 2} = 0.44). Concentrations of TCDD-EQ and TEq ranged from 10.6 to 348 and 13.5 to 69.5 ng/kg, wet weight, respectively. The ratio of TCDD-EQ to TEq ranged from 0.5 to 5.0, with the greatest ratio observed in common carp but the average ratio between TEq and TCDD-EQ was approximately 1.0. In common carp, larger walleye, and medium-sized alewife (Alosa pseudoharengus) there were significant concentrations of TCDD-EQ that could not be accounted for by TEq calculated from an additive model of PCBs, PCDDs, or PCDFs. As much as 75% of the TCDD-EQ in some samples could not be accounted for by TEqs. It is unlikely that PCNs, PCDTs, or polychlorinated diphenyl ethers (PCDEs) occurred at concentrations that were, based on their relative potencies, great enough to contribute significant quantities of TCDD-EQ. The discrepancy between TCDD-EQs and TEqs was not due to antagonisms among congeners or extraction efficiencies.

  13. Mercury and halogenated organic contaminants in river otters (Lontra canadensis) in New Jersey, USA.

    PubMed

    Stansley, William; Velinsky, David; Thomas, Roger

    2010-10-01

    Liver samples collected from New Jersey river otters (Lontra canadensis) in 2005 and 2007 were tested for Hg, organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polybrominated diphenyl ethers (PBDEs). The highest mercury concentrations were found in otters living in the Pinelands region, where acidic soils and surface waters enhance Hg bioavailability. The highest individual Hg concentration was 19.8 µg/g wet weight, approximately 60% of the experimentally determined lethal threshold. Concentrations of OC pesticides were generally similar to those in otters from areas of Oregon and Washington close to agricultural and industrial sources. The geometric mean total PCB concentration (540 ng/g wet wt) was similar to the concentration in otters from the heavily populated and industrialized lower Columbia River in Oregon and Washington. Seven liver samples that were among the highest in terms of total PCBs were analyzed for PCDDs and PCDFs. Polychlorinated dibenzo-p-dioxins were detected in six of the samples at total concentrations ranging from 172 to 2,783 pg/g wet weight. Polychlorinated dibenzofurans were detected in three of the samples at total concentrations ranging from 1.50 to 2,719 pg/g wet weight. The geometric mean PBDE concentration was 10.6 ng/g wet weight, with a range of 0.82 to 436 ng/g wet weight. No statistically significant relationship was observed between liver contaminant concentrations and land use within an 8-km radius of the trapping location. Overall, the data suggest that contaminant concentrations are not high enough to adversely affect the overall otter population in New Jersey. However, contaminant-related effects on the health or reproductive success of individual otters in some areas are possible.

  14. Blood levels of dioxins, furans, dioxin-like PCBs, and TEQs in general populations: a review, 1989-2010.

    PubMed

    Consonni, Dario; Sindaco, Raffaella; Bertazzi, Pier Alberto

    2012-09-01

    A comprehensive worldwide literature review of blood levels of dioxins and dioxin-like compounds in non-exposed adult general populations was performed. The studies published in 1989-2010 reporting information on polychlorinated dibenzo-para-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho-PCBs (nPCBs), mono-ortho-PCBs (mPCBs) levels and Toxic Equivalencies (TEQs, a summary weighted measure of their combined toxicity) were reviewed. TEQs were calculated using as standard the most recent WHO 2005 reevaluation of Toxic Equivalency Factors (TEFs). Weighted multiple regression analyses adjusted for year, subject's age, type of sample analyzed, method used for values below detection limit, and central tendency measure used were performed for each congener and standardized TEQs (log-transformed). We identified 187 studies regarding 29,687 subjects of 26 countries. Year of blood collection ranged from 1985 to 2008. The studies reporting congener levels 161. In adjusted analyses, European countries showed higher levels of most dioxin-like congeners and TEQs. A strong positive association of subjects' age with most congeners and with TEQ values was found, confirming previous findings. Significant decreases over time (1985-2008) were documented for PCCDs, PCDFs, and TEQs including their contributions. No significant decrease was found for non-ortho-PCBs, notably PCB 126. Only some mono-ortho-PCBs showed clear significant declines. Accordingly, TEQs including only PCB contribution did not decrease over time. In interpreting these findings, it should be considered that for dioxin-like PCBs the analysis period was shorter (17 years), since these compounds were first measured in 1992.

  15. Environmental contaminants in male river otters from Oregon and Washington, USA, 1994-1999.

    PubMed

    Grove, Robert A; Henny, Charles J

    2008-10-01

    This study reports hepatic concentrations and distribution patterns of select metals, organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in 180 male river otters (Lontra canadensis) collected from Oregon and Washington, 1994-1999. Seven regional locations of western Oregon and Washington were delineated based on associations with major population centers, industry or agriculture. Cadmium (Cd) was not found above 0.5 microg g(-1), dry weight (dw) in juveniles, but increased with age in adults though concentrations were generally low (nd-1.18 microg g(-1), dw). Regional geometric means for total mercury (THg) ranged from 3.63 to 8.05 microg g(-1), dw in juveniles and 3.46-12.6 microg g(-1) (dw) in adults. The highest THg concentration was 148 microg g(-1), dw from an apparently healthy adult male from the Olympic Peninsula of Washington. Although THg increased with age in adult otters, the occurrence of the more toxic form methylmercury (MeHg) was not evaluated. Mean OC and PCB concentrations reported in this study declined dramatically from those reported in 1978-1979 from the lower Columbia River. Organochlorine pesticide and metabolite means for both juvenile and adult river otter males were all below 100 microg kg(-1), wet weight (ww), with only DDE, DDD and HCB having individual concentrations exceeding 500 microg kg(-1), ww. Mean SigmaPCB concentrations in both juvenile and adult male otters were below 1 microg g(-1) for all regional locations. Mean juvenile and adult concentrations of non-ortho substituted PCBs, PCDDs and PCDFs were in the low ng kg(-1) for all locations studied. PMID:18058253

  16. Atmospheric PCDD/F concentrations in 38 cities of China monitored with pine needles, a passive biosampler.

    PubMed

    Chen, Pei; Mei, Jun; Peng, Ping'an; Hu, Jianfang; Chen, Deyi

    2012-12-18

    Many studies have shown that pine needles are a good biomonitor for atmospheric concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). However, this biomonitor has not been tested in large areas, and the quantitative relationship between concentrations in pine needles and air has not been established. In the present study, we collected pine needles from 38 cities in China. The concentrations of 2,3,7,8-PCDD/Fs were measured by gas chromatography combined with high-resolution mass spectrometry. The total PCDD/F concentrations ranged from 5.4 to 330 pg/g dry weight of pine needles. The pine needles from cities located in central China and three major city agglomerations contained high concentrations of PCDD/Fs, while those from cities in the west and on the coast contained relatively low concentrations. Primary emission and diffusion processes were the main controls of the PCDD/F concentrations in pine needles. Homologue profiles of PCDD/Fs in pine needles were characterized by PCDFs/PCDDs >1 in the industrialized cities and <1 in unindustrialized cities. The congener patterns were dominated by 1,2,3,4,6,7,8-HpCDF and OCDD, indicating that combustion was the major source of the PCDD/Fs. By comparing the PCDD/F concentrations in the pine needles and those in air, we established a preliminary linear relationship between them. Finally, the concentrations in air of PCDD/Fs in the 38 cities of China could be predicted from this relationship.

  17. Impacts of dust storms on PCDD/Fs and regulated harmful matter in a basin area

    NASA Astrophysics Data System (ADS)

    Wu, Tzi-yi; Lin, Yuan-Chung; Chen, Yan-Min; Chang-Chien, Guo-Ping

    2010-08-01

    Few studies have been conducted on the relationship between the high levels of dust particles and the concentrations of atmospheric PCDD/F during dust storm episodes. However, they did not investigate the impact of dust storm on basin areas. This present study shows the dust storm effect on regulated harmful matter and polychlorinated dibenzo- p-dioxin/dibenzofuran (PCDD/F) concentrations in basin areas. The results indicate that the average PM 10 (aerodynamic diameter less than 10 μm), SO 2 (sulfur dioxide), NO 2 (nitrogen oxides), CO (carbon monoxide) and O 3 (ozone) levels during the dust storm were 5.14, 2.30, 1.44, 1.40 and 1.41 times higher than those before the dust storm, respectively. Mean PCDD/F concentrations during the dust storm (0.958 pg Nm -3; 0.0484 pg I-TEQ Nm -3) were significantly higher than those before the dust storm (0.240 pg Nm -3; 0.00705 pg I-TEQ Nm -3). The PCDDs concentration during the dust storm was 1.84 times larger than that before the dust storm, and the PCDFs concentration was 10.2 times larger. Therefore, the dominant contribution of PCDD/Fs concentration during dust storm in the basin areas of northern Taiwan is PCDFs. OCDD concentration measured before dust storm was the highest among the seventeen investigated PCDD/F congeners, accounting for about 64.6% of the total concentration. However, OCDD concentration measured during the dust storm was comparable with the OCDF among the seventeen investigated PCDD/F congeners, accounting for about 24.5% (OCDD) and 22.9% (OCDF) of the total concentration. The above results indicate that the impact of a dust storm on regulated harmful matter and PCDD/F concentrations in the basin area is significant. An investigation of the health risk from dust storms in basin areas is needed.

  18. Deposition fluxes of PCDD/Fs in the area surrounding a steel plant in northwest Italy.

    PubMed

    Onofrio, Maurizio; Spataro, Roberta; Botta, Serena

    2014-06-01

    The paper aims at investigating the contribution of a steel plant located in a rural area in northwestern Italy (700,000 tons of steel/year) to the deposition fluxes of Polychorinated Dibenzo-p-dioxins and Polychorinated dibenzofurans (PCDD/PCDFs) at local level through the analysis of sampling data, literature data, and air dispersion model (AERMOD)output data. Total measured deposition fluxes of PCDD/PCDFs in three monitoring stations were consistent with other studies carried out in Italy in urban and suburban areas and in rural European areas; while these were lower than those measured in other European urban/suburban areas or in sites influenced by industrial sources. Furthermore, the measured fluxes were also compared with the pattern of PCDD/Fs in ambient air sampled at the same sites in a previous study. This comparison showed a similarity between air concentration and deposition patterns of the samples collected at the three monitoring stations and a clear distinction of these from the source. The study was completed with AERMOD simulations, conducted with a mass mean particle diameter of 0.5 μm, according to the particle size distribution of the samples collected at the source. AERMOD calculated deposition fluxes of two to three orders of magnitude lower than those measured in two monitoring points; while in the most distant monitoring station, the deposition fluxes were too low to be calculated by the model. The simulations confirmed that the most distant monitoring station was not subject to emissions from the steel plant. The analysis highlighted the limited influence of the source in the local PCDD/F deposition fluxes.

  19. Studies of the combustion of coal/refuse derived fuels using thermogravimetric-Fourier transform infrared-mass spectrometry

    SciTech Connect

    Lu, Huagang; Li, Jigui; Lloyd, W.G.

    1995-11-01

    According to a report of the Environmental Protection Agency (EPA), `Characterization of Municipal Solid Waste (MSW) in the United States`, the total MSW produced in the U.S. increased from 179 million tons in 1988 to 195 million tons in 1990. The EPA predicted that the country would produce about 216 million tons of garbage in the year 2000. The amount of waste generated and the rapidly declining availability of sanitary landfills has forced most municipalities to evaluate alternative waste management technologies for reducing the volume of waste sent to landfills. The fraction of MSW that is processed by such technologies as separation and recycling, composting, and waste-to-energy was forecast to increase from a few percent today to 30-40% by the year 2000. Waste-to-energy conversion of MSW can appear to be attractive because of the energy recovered, the economic value of recycled materials, and the cost savings derived from reduced landfill usage. However, extra care needs to be taken in burning MSW or refuse-derived fuel (RDF) to optimize the operating conditions of a combustor so that the combustion takes place in an environmentally acceptable manner. For instance, polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) have been found in the precipitator fly ash and flue gas of some incinerator facilities in the United States and Europe. The amount of PCDDs and PCDFs occurs only in the parts-per-billion to parts-per-trillion range, but these chlorinated organics exhibit very high toxicity (LD{sub 50} < 10 {mu}g/Kg). The compound 2,3,7,8-tetrachlorodibenzodioxin has been found to be acnegenic, carcinogenic, and teratogenic. This has slowed or even stopped the construction and operation of waste-to-energy plants.

  20. Characteristics of the abundance of polychlorinated dibenzo-p-dioxin and dibenzofurans, and dioxin-like polychlorinated biphenyls in sediment samples from selected Asian regions in Can Gio, Southern Vietnam and Osaka, Japan.

    PubMed

    Kishida, Masao; Imamura, Kiyoshi; Takenaka, Norimichi; Maeda, Yasuaki; Viet, Pham Hung; Kondo, Akira; Bandow, Hiroshi

    2010-01-01

    The levels of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) were determined in sediment samples from Can Gio, South Vietnam, and Osaka, Japan. Can Gio is known for the defoliation of its mangrove forests by aerial spraying with Agent Orange during the Vietnam War, whereas Osaka is renowned for a PCDD/PCDF pollution accident at a municipal solid-waste incinerator. For comparison, we also analyzed PCDD/PCDFs and DL-PCBs in sediment samples from Hue and Hanoi, Vietnam. The toxic equivalent quantity (TEQ) values in Can Gio were as high as those in Hue, Hanoi, and suburban areas of Osaka, but much lower than those in urban areas of Osaka. The proportion of the World Health Organization (WHO)-TEQ value contributed by 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) in Can Gio was approximately 30%, higher than the values in the other sample areas. These data suggest that residual sedimentary TCDD that originated from aerial spraying of Agent Orange occur in only low concentrations in Can Gio. The main contributors to WHO-TEQ values in Can Gio are natural sources, as in Hue. In contrast, commercial PCBs are the dominant contributors to WHO-TEQ values in Hanoi. In Osaka, agrochemicals used in rice cultivation, the incineration of solid waste, and commercial PCBs equally contributed to WHO-TEQ values at suburban locations. The dumping of incinerator-related materials and/or the inadequate management of commercial PCBs have resulted in significantly elevated WHO-TEQ values of 240-370 ng kg(-1)dw at urban locations in Osaka. PMID:19892385

  1. Long-term sampling of dioxin-like substances from a clinker kiln stack using alternative fuels.

    PubMed

    Rivera-Austrui, J; Martinez, K; Marco-Almagro, L; Abalos, M; Abad, E

    2014-07-01

    The aim of this work is to characterize atmospheric emissions of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) from a cement production plant where the existing clinker production line was completely replaced by a new state-of-the-art installation. The project started in April 2008 with the installation of a long-term sampling system in the stack of the clinker kiln that used petroleum coke as fuel; PCDD/PCDF and dl-PCB emissions were then evaluated for a two year period. To carry out the second part of the study, in 2010 the sampling system was moved to the new installation in which, apart from conventional fuel, recovered derived fuel (RDF) and WWTP sludge were used as alternative fuels. For both the old and new clinker kilns, PCDD/PCDF emission values were well below the limit established by the European Waste Incineration Directive 2000/76/CE (EWID) of 100 pg I-TEQ/Nm(3); values ranged from 0.43 to 2.02 and from 0.07 to 3.31 pg I-TEQ/Nm(3), respectively. dl-PCBs accounted for approximately 25% of the WHO-TEQ toxicity. These results prove that the installation is capable of reducing PCDD/PCDF and dl-PCB emissions when alternative fuels are integrated into the process. In the case of PCDDs/PCDFs, the major contributions to total TEQ were usually from 2,3,7,8-TCDD (owing to its relative abundance) and 2,3,4,7,8-PeCDF (due to its high I-TEF of 0.5); while for dl-PCBs, the major contribution was from PCB-126. The slight shift in the congener profile between the old and new installations was characterized and a regression model was proposed for dl-PCB emissions depending on the RDF flow rate in the clinker.

  2. Exposure to a Mixture of Polychlorinated Biphenyls and Polychlorinated Dibenzofurans Resulted in a Prolonged Time to Pregnancy in Women

    PubMed Central

    Yang, Chiu-Yueh; Wang, Ying-Jan; Chen, Pau-Chung; Tsai, Shaw-Jenq; Guo, Yueliang Leon

    2008-01-01

    Background Polychlorinated biphenyls (PCBs), dibenzofurans (PCDFs), and dibenzodioxins (PCDDs) may affect the female reproductive system in animals and humans. In 1978–1979, a mass poisoning occurred in central Taiwan due to PCB/PCDF-contaminated cooking oil; this incident was called Yucheng (“oil disease” in Chinese). Objective The purpose of our study was to determine whether PCB/PCDF exposure affected fertility in exposed women. Methods After the event, we followed the exposed individuals and a reference group who were sex-, age-, and community-matched. In 2003, we obtained fertility histories from Yucheng and reference women by telephone interview. We used Kaplan–Meier survival curves and multivariable Cox regression to compare time to pregnancy (TTP) between Yucheng and reference women, and we performed multiple logistic regression to determine whether PCB/PCDF exposure caused infertility. Results In total, 412 women responded, with a median TTP of 4 months in Yucheng women and 3 months in reference women (p = 0.019). After adjusting for confounders by Cox regression, we found a fecundability ratio of 0.90 [95% confidence interval (CI), 0.80–1.00] for Yucheng women. Among the 408 women who had noncontraceptive sexual activity for > 12 months, 19.7% of Yucheng women and 9.7% of reference women did not become pregnant (i.e., they were infertile). After we adjusted for confounders by logistic regression, the infertility odds ratio was 2.34 (95% CI, 1.23–4.59) for Yucheng women compared with the reference group. Conclusions We found prolonged TTP and reduced fertility among women previously exposed to PCBs/PCDFs. Because of the limited sample size and the relatively small decrease in the fertility rate, these effects require cautious interpretation and further investigation for confirmation. PMID:18470317

  3. Emissions from southeastern U.S. Grasslands and pine savannas: Comparison of aerial and ground field measurements with laboratory burns

    NASA Astrophysics Data System (ADS)

    Aurell, Johanna; Gullett, Brian K.; Tabor, Dennis

    2015-06-01

    Emissions from prescribed burns of a managed longleaf pine (Pinus palustris) forest and grass/savanna fields in western Florida were measured by simultaneous aerial and ground sampling. Results were compared with measurements made in an open burn laboratory test facility using biomass gathered from the same stands. Measurements included polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), particulate matter (PM2.5), elemental carbon (EC), organic carbon (OC), black carbon (BC), brown carbon (BrC), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). The flaming phase (high modified combustion efficiency) was characterized by high levels of BC and BrC yet low levels of VOCs. In general, ground-based measurements of PM2.5, BC, and BrC reported marginally higher emission factors than those measured in the plume by aerostat (balloon)-lofted instruments. The optically-determined BC emission factor was approximately ten times higher than many previously reported results. Simultaneous BC and EC measurements showed that EC values were, on average, 42% lower than the BC values, lending uncertainty to the common use of EC measurements as a BC surrogate. PAH emission factors were indistinguishable across the sampling scenarios, while PCDDs/PCDFs saw a significant decline in the laboratory testing. Limited distinctions in particle-related emissions between aerial and ground measurements suggest sampling bias between these methods. Emission factor distinctions between laboratory burn simulations and field tests appear primarily related to lower combustion efficiencies in the latter, perhaps due to higher biomass moisture or surface wetness.

  4. Unexpected high PCB and total DDT levels in the breeding population of red kite (Milvus milvus) from Doñana National Park, south-western Spain.

    PubMed

    Gómara, Belén; González, María José; Baos, Raquel; Hiraldo, Fernando; Abad, Esteban; Rivera, Josep; Jiménez, Begoña

    2008-01-01

    This study provides information on the current status of contamination by organochlorines (DDTs, PCBs, PCDDs and PCDFs) in the declining red kite (Milvus milvus L.) population breeding in the Doñana National Park (DNP), south-western Spain. Analyses were performed in addled eggs collected between 1999 and 2001. DDE concentrations ranged from 0.1 to 33.5 microg/g ww, representing more than 86% of the total DDTs. Of the samples studied, 50% showed DDE levels above those associated with reproductive impairment in other raptor species. Concentrations of ortho PCBs (average 36.8 microg/g ww+/-37.7) in 50% of the eggs were much higher than levels reported to cause reduced hatching success, embryo mortality, and deformities in birds (>20 microg/g ww). It is remarkable that average ortho PCB and DDE concentrations showed an increase of one order of magnitude compared to previous data for the species during the 80s. Total PCDD/Fs showed levels in the low pg/g range (7.2-42 pg/g ww), having PCDDs and PCDFs similar contributions in most samples. Total mean TEQs were 238 pg/g (ww), being the range 7.02-667 pg/g (ww). Spatial variation within DNP was observed for PCBs, DDTs, as well as for TEQs. Since some eggs exceeded the NOEL (67%) and LOEL (33%) reported for other raptor species, we would expect the red kite to experience detrimental effects to dioxin-like toxicity. Our results suggest that organochlorine contaminants should be regarded as an element of concern in the population under study, in addition to other conservation problems already reported. Further investigations should be undertaken to identify potential sources of these chemicals in DNP, and to find out if organochlorine contamination is present in other predator species in the area, as well as their potential health effects on individuals and/or populations. PMID:17727950

  5. Release of chlorinated, brominated and mixed halogenated dioxin-related compounds to soils from open burning of e-waste in Agbogbloshie (Accra, Ghana).

    PubMed

    Tue, Nguyen Minh; Goto, Akitoshi; Takahashi, Shin; Itai, Takaaki; Asante, Kwadwo Ansong; Kunisue, Tatsuya; Tanabe, Shinsuke

    2016-01-25

    Although complex mixtures of dioxin-related compounds (DRCs) can be released from informal e-waste recycling, DRC contamination in African e-waste recycling sites has not been investigated. This study examined the concentrations of DRCs including chlorinated, brominated, mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in surface soil samples from the Agbogbloshie e-waste recycling site in Ghana. PCDD/F and PBDD/F concentrations in open burning areas (18-520 and 83-3800 ng/g dry, respectively) were among the highest reported in soils from informal e-waste sites. The concentrations of PCDFs and PBDFs were higher than those of the respective dibenzo-p-dioxins, suggesting combustion and PBDE-containing plastics as principal sources. PXDFs were found as more abundant than PCDFs, and higher brominated analogues occurred at higher concentrations. The median total WHO toxic equivalent (TEQ) concentration in open burning soils was 7 times higher than the U.S. action level (1000 pg/g), with TEQ contributors in the order of PBDFs>PCDD/Fs>PXDFs. DRC emission to soils over the e-waste site as of 2010 was estimated, from surface soil lightness based on the correlations between concentrations and lightness, at 200mg (95% confidence interval 93-540 mg) WHO-TEQ over three years. People living in Agbogbloshie are potentially exposed to high levels of not only chlorinated but also brominated DRCs, and human health implications need to be assessed in future studies. PMID:26474377

  6. Highly purified hexachlorobenzene induces cytochrome P4501A in primary cultures of chicken embryo hepatocytes

    SciTech Connect

    Mundy, Lukas J.; Jones, Stephanie P.; Crump, Doug; Herve, Jessica C.; Konstantinov, Alex; Utley, Fiona; Potter, David; Kennedy, Sean W.

    2010-11-01

    Some uncertainty exists regarding the purity of hexachlorobenzene (HCB) used in past toxicity studies. It has been suggested that reported toxic and biochemical effects initially attributed to HCB exposure may have actually been elicited by contamination of HCB by polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Herein, primary cultures of chicken embryo hepatocytes (CEH) were used to compare the potencies of two lots of reagent-grade hexachlorobenzene (HCB-old [HCB-O] and HCB-new [HCB-N]), highly purified HCB (HCB-P) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as inducers of ethoxyresorufin O-deethylase (EROD) activity, cytochrome P4501A4 (CYP1A4) messenger ribonucleic acid (mRNA) and CYP1A5 mRNA. The study also compared the EROD- and CYP1A4/5 mRNA-inducing potencies of HCB to the potencies of two mono-ortho substituted polychlorinated biphenyls (PCBs), 2,3,3',4,4'-pentachlorobiphenyl (PCB 105) and 2,3'4,4',5-pentachlorobiphenyl (PCB 118). HCB-O, HCB-N and HCB-P all induced EROD activity and up-regulated CYP1A4 and CYP1A5 mRNAs. Induction was not caused by contamination of HCB with PCDDs or PCDFs. Based upon a comparison of the EC{sub 50} and EC{sub threshold} values for EROD and CYP1A4/5 mRNA concentration-response curves, the potency of HCB relative to the potency of TCDD was 0.0001, and was similar to that of PCB 105 and PCB 118. The maximal EROD activity and CYP1A4/5 mRNA expression differed greatly between HCB and TCDD, and may contribute to an overestimation of the ReP value calculated for highly purified HCB.

  7. Assessment of dietary exposure to some persistent organic pollutants in the Republic of Karakalpakstan of Uzbekistan.

    PubMed Central

    Muntean, Nigina; Jermini, Marco; Small, Ian; Falzon, Dennis; Fürst, Peter; Migliorati, Giacomo; Scortichini, Giampiero; Forti, Anna Francesca; Anklam, Elke; von Holst, Christoph; Niyazmatov, Bakhtier; Bahkridinov, Shakub; Aertgeerts, Roger; Bertollini, Roberto; Tirado, Cristina; Kolb, Anthony

    2003-01-01

    A 1999 study heightened long-standing concerns over persistent organic pollutant contamination in the Aral Sea area, detecting elevated levels in breast milk and cord blood of women in Karakalpakstan (western Uzbekistan). These findings prompted a collaborative research study aimed at linking such human findings with evidence of food chain contamination in the area. An international team carried out analyses of organochlorine and organophosphate pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) on samples of 12 foods commonly produced and consumed in Karakalpakstan. Analysis consistently detected long-lasting organochlorine pesticides and their metabolites in all foods of animal origin and in some vegetables such as onions and carrots--two low-cost components of many traditional dishes. Levels of PCBs were relatively low in all samples except fish. Analyses revealed high levels of PCDDs and PCDFs (together often termed "dioxins") in sheep fat, dairy cream, eggs, and edible cottonseed oil, among other foodstuffs. These findings indicate that food traditionally grown, sold, and consumed in Karakalpakstan is a major route of human exposure to several persistent toxic contaminants, including the most toxic of dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). Intake estimations demonstrate that consumption of even small amounts of locally grown food may expose consumers to dioxin levels that considerably exceed the monthly tolerable dioxin intake levels set by the World Health Organization. Data presented in this study allow a first assessment of the risk associated with the consumption of certain food products in Karakalpakstan and highlight a critical public health situation. PMID:12896851

  8. Relationship of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran levels to stable-nitrogen isotope abundance in marine birds and mammals in coastal California

    SciTech Connect

    Jarman, W.M.; Sydeman, W.J.; Hobson, K.A.; Bergqvist, P.A.

    1997-05-01

    Levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in common murre (Uria aalge), Brandt`s cormorant (Phalacrocorax penicillatus), rhinoceros auklet (Cerorhinca monocerata), and pigeon guillemot (Cepphus columba) eggs, and Steller sea lion (Eumetopias jubatus) blubber collected from the Gulf of the Farallones National Marine Sanctuary in 1993. In addition, the samples were analyzed for stable-nitrogen isotopes ({delta}{sup 15}N). Of the PCDDs and PCDFs, the 2,3,7,8-TCDD (TCDD) and 2,3,7,8-TCDF (TCDF) congeners were the most prominent in the birds. The levels of TCDD in the eggs ranged from 0.2 to 6.6 ng/wet kg in the pigeon guillemot and Brandt`s cormorant, respectively. The TCDF ranged from 0.30 to 2.25 ng/kg in the pigeon guillemot and Brandt`s cormorant eggs, respectively. Other prominent PCDD and PCDF congeners detected in all bird species were 1,2,3,6,7,8-HxCDD, 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD and 1,2,3,4,6,7,8-HpCDD. In the Steller sea lion the most prominent congeners were 1,2,3,7,8-PeCDD at 3.2 ng/kg, 2,3,7,8-TCDD at 2.9 ng/kg, OCDF at 2.2 ng/kg, 1,2,3,6,7,8-HxCDD at 1.92 ng/kg, and 1,2,3,4,7,8-HxCDF at 1.3 ng/kg. Stable-nitrogen values ranged from 16.9% in the pigeon guillemot and rhinoceros auklet to 19.8% in the Steller sea lion.

  9. Polycyclic aromatic hydrocarbons in oysters and sediments from the Yatsushiro Sea, Japan: comparison of potential risks among PAHs, dioxins and dioxin-like compounds in benthic organisms.

    PubMed

    Nakata, Haruhiko; Uehara, Kiriko; Goto, Yuta; Fukumura, Miki; Shimasaki, Hideyuki; Takikawa, Kiyoshi; Miyawaki, Takashi

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) were analyzed in oysters collected from 18 stations in the Yatsushiro Sea, western Japan. PAHs were detected in all samples analyzed, and the highest concentration (mean 230 ng/g wet weight) was found in oysters from Tanoura Bay. The high molecular weight PAHs to low molecular weight PAHs ratios in oysters from Tanoura Bay were higher than at other stations. Sediment samples collected from 42 stations in Tanoura Bay were analyzed for PAHs to understand their concentrations and distribution. Higher concentrations were found in sediment samples at two stations in the southern inner bay (mean 30,200 ng/g dry weight), which were approximately two orders of magnitude higher than at a reference site. These observations strongly suggest severe contamination and significant sources of PAHs in Tanoura Bay. Dioxins and dioxin-like compounds (PCDFs, and non- and mono-ortho coplanar PCBs) were analyzed in sediments from eight stations in Tanoura Bay. The concentrations were comparable to, or lower than, at the reference sites, suggesting that there are no specific sources of these compounds in this bay. PAH, dioxins and dioxin-like compounds DR-CALUX relative potencies (REP) were applied to the sediment concentrations to evaluate the potential for toxicological effects on benthic organisms. PAHs made the highest contribution to the total REP concentration, supplying 99% of the total REP, followed by PCDDs (0.18%), PCDFs (0.04%), and PCBs (<0.001%). In this area, PAHs appear to be the most important Ah receptor binding chemicals for potential toxicity to benthic species.

  10. Influence of process changes on PCDD/Fs produced in an iron ore sintering plant

    SciTech Connect

    Guerriero, E.; Bianchini, M.; Gigliucci, P.F.; Guarnieri, A.; Mosca, S.; Rossetti, G.; Varde, M.; Rotatori, M.

    2009-01-15

    This study investigated the influence of different charge typologies and additives on the PCDD/Fs amount produced and on the congener profiles in an iron ore sintering plant. Many tests were carried out combining different typologies of charge (iron materials) and solid fuel ('coke breeze' or 'anthracite') with or without the use of urea. The PCDD/Fs produced ranged from 1.2 to 22.7 {mu} g I-TEQ/ton of agglomerate, whereas the PCDD/Fs released to the ambient air ranged from 0.10 to 1.92 ng I-TEQ/Nm{sup 3} because of cleaning in an electrostatic precipitator (ESP) and a Wetfine scrubber (WS). A more homogeneous charge with a higher amount of fine particles charge appeared to produce a lower PCDD/Fs concentration due to a better combustion but this hypothesis needs further investigations on charges having different dimension particles. Only a synergitic action of urea and anthracite was able to reduce the high PCDD/Fs content due to the bad combustion of the more inhomogeneous charge with a lower amount of fine particles. The congener profile was a typical combustion process fingerprint because the PCDFs predominated, the highly chlorinated congeners (HeptaCDD and OctaCDD) prevailed in PCDDs, whereas in PCDFs the profile was more varied; 1,2,3,4,6,7,8-HeptaCDF was the main contributor to the total concentration while 2,3,4,7,8-PentaCDF was the main contributor to the I-TEQ concentration. Whereas all the parameters under scrutiny influenced strongly the amount of PCDD/Fs produced, they affected only slightly the fingerprint of PCDD/Fs. In all cases studied, the reduction obtained using urea, anthracite, or the more homogeneous charge with a higher amount of fine particles was slightly greater on the higher chlorinated congeners in respect to the lower ones.

  11. Accumulation of halogenated aromatic hydrocarbons and activities of cytochrome P450 and glutathione S-transferase in crabs (Eriocheir japonicus) from Japanese rivers

    SciTech Connect

    Ishizuka, Mayumi; Iwata, Hisato; Kazusaka, Akio; Fujita, Shoichi; Sakiyama, Takanori; Fukushima, Minoru

    1998-08-01

    The hepatopancreases of freshwater crabs (Eriocheir japonicus) collected from three Japanese rivers were analyzed for planar halogenated aromatic hydrocarbons (HAHs), including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (PCBs). The hepatic glutathione S-transferase (GST)-dependent enzyme activities in the crab hepatopancreas were also measured to examine their potential as biomarkers for the contaminants. Crabs from the Tone River, which runs through industrial, agricultural, and urban areas, have the highest concentrations of HAHs (4,100 pg/g fat weight), followed by those from the Barato River (2,430--2,970 pg/g fat weight), whereas crabs from the Shiribetsu River were relatively less contaminated (1,350--1,800 pg/g fat weight). Identification and numerous PCDD and PCDF congeners in crabs from the Barato and Shiribetsu Rivers were notably contaminated with 1,3,6,8- and 1,3,7,9-TeCDD congeners, which suggests that a possible source was chlornitrofen, which has been extensively used in paddy fields as a herbicide. Calculation of 2,3,7,8-tetrachlorinated dibenzo-p-dioxin toxic equivalents (TEQs) showed that the causal contaminants of higher TEQs in crabs from the Tone River (94.7 TEQ picograms per gram fat weight) were PCDDs and PCDFs, although the most important contributor to the total TEQs was coplanar PCBs (49.95%). The crab hepatopancreas appeared to have abilities to transfer glutathione to 1-chloro-2,4-nitrobenzene (CDNB) and 3,4-dichloronitrobenzene (DCNB). The crabs with the highest TEQ levels showed the highest GST activities.

  12. Dioxin transfer from sediment to the infaunal surface deposit-feeding polychaete Perinereis nuntia in a laboratory-rearing experiment.

    PubMed

    Kono, Kumiko; Tanaka, Hiroyuki; Koyama, Jiro

    2010-07-01

    In the presented study a laboratory experiment was conducted to investigate the transfer of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) from environmentally contaminated marine sediment to an infaunal surface deposit-feeding polychaete, Perinereis nuntia. Polychaetes were exposed to contaminated sediment for 42 d, and elimination of these compounds was studied for an additional 28 d. The sediment uptake rate coefficients (ks), elimination rate constants (k2), and the biota-sediment accumulation factors (BSAFs) were determined for PCDDs, PCDFs (PCDD/Fs), and dioxin-like PCBs. Each of these compounds was transferred from sediment to polychaete except for hepta- and octachlorinated PCDD/Fs. The BSAFs for dioxin-like PCBs (0.13-2.2) were significantly higher than those for PCDD/Fs (0.00022-0.36). The BSAF, ks, and k2 values obtained in the present study indicate that the bioaccumulation characteristics of PCDD/Fs in polychaete are similar to those in fish, and depend on their physical and chemical properties such as hydrophobicity and size of molecules. The ks values for PCDD/Fs and dioxin-like PCBs declined with an increase in their log KOW values, indicating a decrease in bioavailability. The negative exponential relationships of k2 versus KOW were observed for these compounds. The slope for the log-normalized regression of k2 versus KOW for the PCDD/Fs was smaller than that for the dioxin-like PCBs and that of ks versus KOW for the PCDD/Fs. Therefore, the negative exponential relationship of BSAF versus KOW was observed for PCDD/Fs, but not for dioxin-like PCBs.

  13. Polychlorinated dioxins, furans (PCDD/Fs), and polychlorinated biphenyls (PCBs) and their trends in Canadian human milk from 1992 to 2005.

    PubMed

    Ryan, John Jake; Rawn, Dorothea F K

    2014-05-01

    More than 300 samples of human milk were collected from individuals residing in various regions across Canada in the years 1992 to 2005. The milks were taken from the main populated areas east to west in southern Canada as well as from the region of Nunavik in northern Quebec and analysed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs). The concentrations, expressed in ng kg(-1) milk lipid, show an overall decrease of virtually all compounds examined including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), World Health Organization 2005 toxic equivalents (WHO2005-TEQ) PCDD/PCDFs, WHO2005-TEQ dioxin-like PCBs (dl-PCBs), and total PCBs. Median values of 2,3,7,8-TCDD changed from about 1.5 ng kg(-1) milk lipid in 1992 to 0.8 ng kg(-1) in 2005 while the median WHO2005-TEQ PCDD/F fell from about 14-7 ng kg(-1) milk lipid in the same period. The concentrations of PCDD/Fs and PCBs in samples from Nunavik, which is in Arctic Quebec, were higher than those observed in milk from southern Quebec although this difference was not large. Over two time periods, milk samples from Hamilton, Ontario showed slightly higher levels of PCBs than Austin, Texas, USA--a North American city of similar size and development but with more than twice the PBDE exposure. When compared with earlier human milk data going back to the early 1980s, this large data set shows a steady decline of human exposure to POPs in Canada by a factor of about four times.

  14. Toxic equivalency factors of polybrominated dibenzo-p-dioxin, dibenzofuran, biphenyl, and polyhalogenated diphenyl ether congeners based on rainbow trout early life stage mortality.

    PubMed

    Hornung, M W; Zabel, E W; Peterson, R E

    1996-10-01

    Polybrominated and polychlorinated biphenyls (PBBs/PCBs), dibenzo-p-dioxins (PBDDs/PCDDs), dibenzofurans (PBDFs/PCDFs), and diphenyl ethers (PBDEs/PCDEs) are persistent, lipophilic environmental contaminants that may pose a risk to fish early life stage survival. To determine this potential risk, a rainbow trout early life stage mortality bioassay was used in which the potency of individual polybrominated chemicals was compared to the potency of the most potent polychlorinated chemical in these classes, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Following injection of newly fertilized rainbow trout eggs, fish-specific toxic equivalency factors (TEFs) were calculated as the molar ratio of TCDD LD50 to brominated compound LD50. Signs of toxicity were identical to those produced by polychlorinated TCDD-like chemicals and included yolk sac edema, pericardial edema, multifocal hemorrhages, reduced growth, and craniofacial malformations. Polybrominated dibenzo-p-dioxins, dibenzofurans, and biphenyls exhibited decreased potency with increased bromine substitution. Only 2,3,7,8-TBDD was more potent than 2,3,7,8-TCDD, whereas other polybrominated dibenzo-p-dioxins were equipotent or less potent than identically substituted polychlorinated dibenzo-p-dioxins in this assay. Although two PBDF congeners were equipotent to identically substituted PCDFs, 2,3,7,8-TBDF was 9-fold more potent than 2,3,7,8-TCDF. Both 3,3',4,4'-TBB and 3,3',4,4',5,5'-HxBB were 10-fold more potent than identically substituted polychlorinated biphenyls. The halogenated diphenyl ethers and di-ortho polybrominated biphenyls were inactive in this assay. Thus, in this in vivo assay the polybrominated and polychlorinated TCDD-like chemicals were not always equally potent. To assess the risk posed by mixtures of these chemicals to feral fish populations, fish-specific TEFs for both polybrominated and polychlorinated chemicals should be used.

  15. Release of chlorinated, brominated and mixed halogenated dioxin-related compounds to soils from open burning of e-waste in Agbogbloshie (Accra, Ghana).

    PubMed

    Tue, Nguyen Minh; Goto, Akitoshi; Takahashi, Shin; Itai, Takaaki; Asante, Kwadwo Ansong; Kunisue, Tatsuya; Tanabe, Shinsuke

    2016-01-25

    Although complex mixtures of dioxin-related compounds (DRCs) can be released from informal e-waste recycling, DRC contamination in African e-waste recycling sites has not been investigated. This study examined the concentrations of DRCs including chlorinated, brominated, mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in surface soil samples from the Agbogbloshie e-waste recycling site in Ghana. PCDD/F and PBDD/F concentrations in open burning areas (18-520 and 83-3800 ng/g dry, respectively) were among the highest reported in soils from informal e-waste sites. The concentrations of PCDFs and PBDFs were higher than those of the respective dibenzo-p-dioxins, suggesting combustion and PBDE-containing plastics as principal sources. PXDFs were found as more abundant than PCDFs, and higher brominated analogues occurred at higher concentrations. The median total WHO toxic equivalent (TEQ) concentration in open burning soils was 7 times higher than the U.S. action level (1000 pg/g), with TEQ contributors in the order of PBDFs>PCDD/Fs>PXDFs. DRC emission to soils over the e-waste site as of 2010 was estimated, from surface soil lightness based on the correlations between concentrations and lightness, at 200mg (95% confidence interval 93-540 mg) WHO-TEQ over three years. People living in Agbogbloshie are potentially exposed to high levels of not only chlorinated but also brominated DRCs, and human health implications need to be assessed in future studies.

  16. Scaling up a treatment to simultaneously remove persistent organic pollutants and heavy metals from contaminated soils.

    PubMed

    Rivero-Huguet, Mario; Marshall, William D

    2011-04-01

    Soil washing is a treatment process that can be used to remediate both organic and inorganic pollutants from contaminated soils, sludges, and sediments. A soil washing procedure was evaluated utilizing about 100g samples of soil that had been field-contaminated with arsenic, chromium, copper, pentachlorophenol (PCP), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The highest level of mobilization/detoxification was achieved in three soil washes with a mixture of 0.1M [S,S]-ethyelnediaminedisuccinate ([S,S]-EDDS) and 2% Brij 98 at pH 9 with 20 min of ultrasonication treatment at room temperature. This combination mobilized 70% of arsenic, 75% of chromium, 80% of copper, 90% of PCP, and 79% of PCDDs and PCDFs, so that the decontaminated soil met the maximum acceptable concentrations of the generic C-level criteria regulated by the Ministère du Développement Durable, de l'Environnement et des Parcs for the Province of Québec, Canada. The organic pollutants were back-extracted from the aqueous suspension with hexane. Heavy metals were virtually completely precipitated from the aqueous washing suspension with Mg(0) particles at room temperature. The PCP was detoxified by catalytic hydrodechlorination with a stream of 5% (v/v) H(2)-supercritical CO(2) that transported the organosoluble fraction through a reaction chamber containing 2% Pd/γ-Al(2)O(3). In toto, this soil washing procedure demonstrates that persistent organic pollutants and selected heavy metals can be co-extracted efficiently from a field-contaminated soil with three successive washes with the same soil washing solution containing [S,S]-EDDS and a non-ionic surfactant (Brij 98) in admixture. An industrial-scale ex situ soil washing procedure with a combination of a non-ionic surfactant and a complexing reagent seems to be a plausible remediation technique for this former wooden utility pole storage facility. PMID:21354593

  17. Landfill mining from a deposit of the chlorine/organochlorine industry as source of dioxin contamination of animal feed and assessment of the responsible processes.

    PubMed

    Torres, João Paulo Machado; Leite, Claudio; Krauss, Thomas; Weber, Roland

    2013-04-01

    In 1997, the Polychlorinated dibenzo-para-dioxin (PCDD)/Polychlorinated dibenzofuran (PCDF) concentrations in dairy products in Germany and other European countries increased. The PCDD/PCDF source was contaminated lime used in Brazilian citrus pulp pellets. The contaminated lime was mined from an industrial dump site. However, the detailed origin of the PCDD/PCDFs in the lime was not revealed. This paper investigates the contamination origin and describes the link between lime milk from the dumpsite of a chlorine/organochlorine industry and the contaminated lime. The contaminated lime stem from mining at the corporate landfill of Solvay Indupa in Sao Paulo. The landfill was used for 40 years for deposition of production residues and closed in 1996. The factory operated/operates at least two processes with potentially high PCDD/PCDFs releases namely the oxychlorination process for production of ethylene dichloride (EDC) and the chlor-alkali process. The main landfilled waste was lime milk (1.4 million tons) from the vinyl chloride monomer production (via the acetylene process) along with residues from other processes. The PCDD/PCDF fingerprint revealed that most samples from the chemical landfill showed an EDC PCDD/PCDF pattern with a characteristic octachlorodibenzofuran dominance. The PCDD/PCDF pattern of a Rio Grande sediment samples downstream the facility showed a chlor-alkali pattern with a minor impact of the EDC pattern. The case highlights that PCDD/PCDF- and persistent organic pollutants-contaminated sites need to be identified in a comprehensive manner as required by the Stockholm Convention (article 6) and controlled for their impact on the environment and human health. Landfill mining and reuse of materials from contaminated deposits should be prohibited.

  18. Assessment of dietary exposure to some persistent organic pollutants in the Republic of Karakalpakstan of Uzbekistan.

    PubMed

    Muntean, Nigina; Jermini, Marco; Small, Ian; Falzon, Dennis; Fürst, Peter; Migliorati, Giacomo; Scortichini, Giampiero; Forti, Anna Francesca; Anklam, Elke; von Holst, Christoph; Niyazmatov, Bakhtier; Bahkridinov, Shakub; Aertgeerts, Roger; Bertollini, Roberto; Tirado, Cristina; Kolb, Anthony

    2003-08-01

    A 1999 study heightened long-standing concerns over persistent organic pollutant contamination in the Aral Sea area, detecting elevated levels in breast milk and cord blood of women in Karakalpakstan (western Uzbekistan). These findings prompted a collaborative research study aimed at linking such human findings with evidence of food chain contamination in the area. An international team carried out analyses of organochlorine and organophosphate pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) on samples of 12 foods commonly produced and consumed in Karakalpakstan. Analysis consistently detected long-lasting organochlorine pesticides and their metabolites in all foods of animal origin and in some vegetables such as onions and carrots--two low-cost components of many traditional dishes. Levels of PCBs were relatively low in all samples except fish. Analyses revealed high levels of PCDDs and PCDFs (together often termed "dioxins") in sheep fat, dairy cream, eggs, and edible cottonseed oil, among other foodstuffs. These findings indicate that food traditionally grown, sold, and consumed in Karakalpakstan is a major route of human exposure to several persistent toxic contaminants, including the most toxic of dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). Intake estimations demonstrate that consumption of even small amounts of locally grown food may expose consumers to dioxin levels that considerably exceed the monthly tolerable dioxin intake levels set by the World Health Organization. Data presented in this study allow a first assessment of the risk associated with the consumption of certain food products in Karakalpakstan and highlight a critical public health situation. PMID:12896851

  19. Dioxin formation from waste incineration.

    PubMed

    Shibamoto, Takayuki; Yasuhara, Akio; Katami, Takeo

    2007-01-01

    There has been great concern about dioxins-polychlorinated dibenzo dioxins (PCDDs), polychlorinated dibenzo furans (PCDFs), and polychlorinated biphenyls (PCBs)-causing contamination in the environment because the adverse effects of these chemicals on human health have been known for many years. Possible dioxin-contamination has received much attention recently not only by environmental scientists but also by the public, because dioxins are known to be formed during the combustion of industrial and domestic wastes and to escape into the environment via exhaust gases from incinerators. Consequently, there is a pressing need to investigate the formation mechanisms or reaction pathways of these chlorinated chemicals to be able to devise ways to reduce their environmental contamination. A well-controlled small-scale incinerator was used for the experiments in the core references of this review. These articles report the investigation of dioxin formation from the combustion of various waste-simulated samples, including different kinds of paper, various kinds of wood, fallen leaves, food samples, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polyvinylidene chloride, polyethylene tetraphthalate (PET), and various kinds of plastic products. These samples were also incinerated with inorganic chlorides (NaCl, KCl, CuCI2, MgCl2, MnCl2, FeCl2, CoCl2, fly ash, and seawater) or organic chlorides (PVC, chlordane, and pentachlorophenol) to investigate the role of chlorine content and/or the presence of different metals in dioxin formation. Some samples, such as newspapers, were burned after they were impregnated with NaCl or PVC, as well as being cocombusted with chlorides. The roles of incineration conditions, including chamber temperatures, O2 concentrations, and CO concentrations, in dioxin formation were also investigated. Dioxins (PCDDs, PCDFs, and coplanar-PCBs) formed in the exhaust gases from a controlled small-scale incinerator, where experimental waste

  20. Long-term sampling of dioxin-like substances from a clinker kiln stack using alternative fuels.

    PubMed

    Rivera-Austrui, J; Martinez, K; Marco-Almagro, L; Abalos, M; Abad, E

    2014-07-01

    The aim of this work is to characterize atmospheric emissions of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) from a cement production plant where the existing clinker production line was completely replaced by a new state-of-the-art installation. The project started in April 2008 with the installation of a long-term sampling system in the stack of the clinker kiln that used petroleum coke as fuel; PCDD/PCDF and dl-PCB emissions were then evaluated for a two year period. To carry out the second part of the study, in 2010 the sampling system was moved to the new installation in which, apart from conventional fuel, recovered derived fuel (RDF) and WWTP sludge were used as alternative fuels. For both the old and new clinker kilns, PCDD/PCDF emission values were well below the limit established by the European Waste Incineration Directive 2000/76/CE (EWID) of 100 pg I-TEQ/Nm(3); values ranged from 0.43 to 2.02 and from 0.07 to 3.31 pg I-TEQ/Nm(3), respectively. dl-PCBs accounted for approximately 25% of the WHO-TEQ toxicity. These results prove that the installation is capable of reducing PCDD/PCDF and dl-PCB emissions when alternative fuels are integrated into the process. In the case of PCDDs/PCDFs, the major contributions to total TEQ were usually from 2,3,7,8-TCDD (owing to its relative abundance) and 2,3,4,7,8-PeCDF (due to its high I-TEF of 0.5); while for dl-PCBs, the major contribution was from PCB-126. The slight shift in the congener profile between the old and new installations was characterized and a regression model was proposed for dl-PCB emissions depending on the RDF flow rate in the clinker. PMID:24742561

  1. Comparison Between a Rapid Biological Screening Method (EPA 4425) for TCDDs/TCDFs and Chemical Analytical Methods

    SciTech Connect

    Anderson, Jack W.; Jones, Jennifer M.; McCoy, Daniel L.; Fujita, Akira; Yamamoto, Taichi; Iijima, Satoshi

    2003-08-01

    Seven polychlorinated dibenzo-p-dioxins (PCDDs), ten polychlorinated dibenzofurans (PCDFs) as well as twelve polychlorinated biphenyls (PCBs) are collectively referred to as dioxin-like compounds. The World Health Organization toxic equivalency factors (TEFs) for these persistent chlorinated organic compounds and their measured concentrations are used to produce the toxic equivalency quotient (TEQ) of a sample. TEF values are partially based on a common mechanism involving binding of the chemical to the aryl hydrocarbon receptor (AhR). Biological methods for the determination of TEQs are based on the assumption that all dioxin-related compounds act through the Ah receptor signal transduction pathway. Based on the biochemical response of CYP1A activation via the AhR, in vitro systems that utilize a reporter gene under transcriptional control of CYP1A have been developed. Several investigations have reported on the success of utilizing biological test systems to detect PCDDs, PCDFs, PCBs in environmental samples. The P450 Human Reporter Gene System assay (EPA Method 4425) utilizes a human hepatoma cell line (HepG2) in which a plasmid containing the human CYP1A1 promoter and 5'-flanking sequences with three xenobiotic responsive elements (XREs) fused to the luciferase reporter gene. The enzyme luciferase is produced in the presence of compounds that bind the XREs, and can be detected by a simple assay that measures relative light units with a luminometer. Method 4425, used by Columbia Analytical Services (CAS), has gained acceptance as a rapid and inexpensive approach for screening solvent extracts of environmental samples of soil, sediment, tissue, and water to detect compounds that activate the AhR. Investigations in the U. S. and Japan comparing the results of 4425 and standard high-resolution GC/MS (HRGC/HRMS) will be reported here. The purpose of making these comparisons is to determine if risk assessments for large dioxin sites both before and after remediation

  2. Priority persistent contaminants in people dwelling in critical areas of Campania Region, Italy (SEBIOREC biomonitoring study).

    PubMed

    De Felip, Elena; Bianchi, Fabrizio; Bove, Crescenzo; Cori, Liliana; D'Argenzio, Angelo; D'Orsi, Giancarlo; Fusco, Mario; Miniero, Roberto; Ortolani, Rosanna; Palombino, Raffaele; Parlato, Antonino; Pelliccia, Maria Grazia; Peluso, Filomena; Piscopo, Giovanni; Pizzuti, Renato; Porpora, Maria Grazia; Protano, Domenico; Senofonte, Oreste; Spena, Silvana Russo; Simonetti, Andrea; di Domenico, Alessandro

    2014-07-15

    To investigate if protracted living in degraded environments of the Caserta and Naples provinces (Campania Region, Italy) had an impact on exposure of local people, highly toxic persistent contaminants were measured in blood, blood serum, and human milk of a large number of healthy donors. Sampling was carried out from 2008 to 2009. Blood was collected from over 850 20-64-year old donors; by pooling, 84 blood and 84 serum samples were obtained. Milk was donated by 52 mothers: specimens were pooled into six samples. Polychlorodibenzodioxins (PCDDs), polychlorodibenzofurans (PCDFs), and polychlorobiphenyls (PCBs, dioxin-like (DL) and non-dioxin-like (Σ6PCBs)), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were measured in serum (organic biomarkers) and blood (metals); these chemicals and polybromobiphenyl ethers (Σ9PBDEs) were analyzed in milk. PCDD+PCDF, DL-PCB, TEQTOT, and Σ6PCB concentration ranges (medians) in serum were 6.26-23.1 (12.4), 3.42-31.7 (11.5), 10.0-52.8 (23.9) pgTEQ97/g fat, and 55.5-647 (219) ng/g fat, respectively, while in milk concentration ranges were 5.99-8.77, 4.02-6.15, 10.0-14.2 pgTEQ97/g fat, and 48.7-74.2 ng/g fat. Likewise, As, Cd, Hg, and Pb findings in blood spanned 2.34-13.4 (5.83), 0.180-0.930 (0.475), 1.09-7.60 (2.60), 10.2-55.9 (28.8) μg/L, respectively; only Pb could be measured in milk (2.78-5.99 μg/L). Σ9PBDE levels in milk samples were 0.965-6.05 ng/g fat. Biomarkers' concentrations were found to be compatible with their current values in European countries and in Italy, and consistent with an exposure primarily determined by consumption of commercial food from the large distribution system. Based on relatively higher biomarker values within the hematic biomonitoring database, the following municipalities were flagged as possibly deserving attention for health-oriented interventions: Brusciano and Caivano (As), Giugliano (Hg), Pianura (PCDDs+PCDFs), and Qualiano-Villaricca (As, Hg). The analysis of samples

  3. Relative potency of polychlorinated dibenzo-p-dioxins and dibenzofurans for inducing mixed-function oxygenase activity in rainbow trout

    SciTech Connect

    Parrott, J.L.; Dixon, D.G.; Hodson, P.V.; Servos, M.R.; Huestis, S.L.

    1995-06-01

    Toxic equivalent factors (TEFs) were generated for various polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) to compare the relative potencies as inducers of liver mixed-function oxygenase (MFO) activity in rainbow trout (Oncorhynchus mykiss). Trout, dosed orally with one of five PCDD congeners, either [{sup 3}H]-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PnCDD), 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (1,2,3,6,7,8-HxCDD), [{sup 14}C]-1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (1,2,3,4,7,8-HxCDD), or [{sup 14}C]-1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD) or one of four PCDF congeners, either 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-pentachlorodibenzofuran (1,2,3,7,8-PnCDF), 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PnCDF), or 1,2,3,4,7,8--hexachlorodibenzofuran (HxCDF), showed increases in liver ethoxyresorufin O-deethylase (EROD) activity up to 250-fold. Liver concentrations of congeners were better predictors of EROD activity than oral dose. TEFs, ratios of the potency of each congener to that of TCDD, were calculated comparing ``threshold`` PCDD concentrations that induced EROD significantly above control levels. In cases of nonparallel dose-response curves between congeners, these comparisons are more relevant to environmental situations as PCDDs are compared at concentrations closer to those in the environment, instead of at higher pharmaceutical levels. Threshold-based TEFs were: PnCDD, 1.8; 1,2,3,6,7,8-HxCDD and 1,2,3,4,7,8-HxCDD, 0.4; HpCDD, 0.05; 2,3,4,7,8-PnCDF, 2; TCDF, 0.5; 1,2,3,7,8-PnCDF and HxCDF, 0.4. The ranking of potencies of the PCDFs was the same in fish as in mammalian tests, with the exception of PnCDD and 2,3,4,7,8-PnCDF, which were more potent to fish than was TCDD.

  4. Patterns, trends, and toxicological significance of chlorinated hydrocarbon and mercury contaminants in bald eagle eggs from the Pacific coast of Canada, 1990-1994.

    PubMed

    Elliott, J E; Norstrom, R J; Smith, G E

    1996-10-01

    Bald eagle (Haliaeetus leucocephalus) eggs were collected during incubation, 1990-1992, from 16 nests near three bleached-kraft pulp mills, from six nests in the Fraser River estuary and from seven nests at a reference site on the Pacific coast of Canada. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were present in all eggs in a qualitatively similar pattern among sites. Mean concentrations of 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) were significantly higher in eggs collected from near three kraft pulp mill sites in the Strait of Georgia (44, 45, 84 ng/kg) than from the reference area in Johnstone Strait (15 ng/kg). There were few differences among sites in mean organochlorine pesticide levels, indicating the diffuse distribution of those chemicals and the domination of atmospheric inputs. Mean concentrations of total polychlorinated biphenyls (PCBs) were highest in eggs from the Strait of Georgia (4.86 mg/kg) and the PCB congener pattern was significantly different between that area and both the lower Fraser valley and Johnstone Strait. Mean mercury concentrations, which were mainly methyl-mercury, were significantly higher in eggs collected from the lower Fraser Valley (0.258 mg/kg) and Johnstone Strait (0.294 mg/kg) compared to the Strait of Georgia (0.188 mg/kg). Individual and regional variation in concentrations of organochlorine pesticides, PCBs and mercury in eagle eggs were thought to be influenced mainly by dietary differences. Toxicologically, in 1990, mean TCDD-toxic equivalents (TEQs) in bald eagle eggs were about two-fold greater than a lowest-observed-effect level, suggested elsewhere for this species, of 210 ng/kg TEQs. In the Strait of Georgia, PCCDs and PCDFs made a greater contribution to TEQs than non-ortho and mono-ortho PCBs, whereas the reverse was true for eggs outside the strait. Mean eggshell thickness was less than the pre-1947 value at all sites, although there was no significant relationship

  5. A protein secretion system linked to bacteroidete gliding motility and pathogenesis.

    PubMed

    Sato, Keiko; Naito, Mariko; Yukitake, Hideharu; Hirakawa, Hideki; Shoji, Mikio; McBride, Mark J; Rhodes, Ryan G; Nakayama, Koji

    2010-01-01

    Porphyromonas gingivalis secretes strong proteases called gingipains that are implicated in periodontal pathogenesis. Protein secretion systems common to other Gram-negative bacteria are lacking in P. gingivalis, but several proteins, including PorT, have been linked to gingipain secretion. Comparative genome analysis and genetic experiments revealed 11 additional proteins involved in gingipain secretion. Six of these (PorK, PorL, PorM, PorN, PorW, and Sov) were similar in sequence to Flavobacterium johnsoniae gliding motility proteins, and two others (PorX and PorY) were putative two-component system regulatory proteins. Real-time RT-PCR analysis revealed that porK, porL, porM, porN, porP, porT, and sov were down-regulated in P. gingivalis porX and porY mutants. Disruption of the F. johnsoniae porT ortholog resulted in defects in motility, chitinase secretion, and translocation of a gliding motility protein, SprB adhesin, to the cell surface, providing a link between a unique protein translocation system and a motility apparatus in members of the Bacteroidetes phylum. PMID:19966289

  6. A protein secretion system linked to bacteroidete gliding motility and pathogenesis

    PubMed Central

    Sato, Keiko; Naito, Mariko; Yukitake, Hideharu; Hirakawa, Hideki; Shoji, Mikio; McBride, Mark J.; Rhodes, Ryan G.; Nakayama, Koji

    2009-01-01

    Porphyromonas gingivalis secretes strong proteases called gingipains that are implicated in periodontal pathogenesis. Protein secretion systems common to other Gram-negative bacteria are lacking in P. gingivalis, but several proteins, including PorT, have been linked to gingipain secretion. Comparative genome analysis and genetic experiments revealed 11 additional proteins involved in gingipain secretion. Six of these (PorK, PorL, PorM, PorN, PorW, and Sov) were similar in sequence to Flavobacterium johnsoniae gliding motility proteins, and two others (PorX and PorY) were putative two-component system regulatory proteins. Real-time RT-PCR analysis revealed that porK, porL, porM, porN, porP, porT, and sov were down-regulated in P. gingivalis porX and porY mutants. Disruption of the F. johnsoniae porT ortholog resulted in defects in motility, chitinase secretion, and translocation of a gliding motility protein, SprB adhesin, to the cell surface, providing a link between a unique protein translocation system and a motility apparatus in members of the Bacteroidetes phylum. PMID:19966289

  7. A protein secretion system linked to bacteroidete gliding motility and pathogenesis.

    PubMed

    Sato, Keiko; Naito, Mariko; Yukitake, Hideharu; Hirakawa, Hideki; Shoji, Mikio; McBride, Mark J; Rhodes, Ryan G; Nakayama, Koji

    2010-01-01

    Porphyromonas gingivalis secretes strong proteases called gingipains that are implicated in periodontal pathogenesis. Protein secretion systems common to other Gram-negative bacteria are lacking in P. gingivalis, but several proteins, including PorT, have been linked to gingipain secretion. Comparative genome analysis and genetic experiments revealed 11 additional proteins involved in gingipain secretion. Six of these (PorK, PorL, PorM, PorN, PorW, and Sov) were similar in sequence to Flavobacterium johnsoniae gliding motility proteins, and two others (PorX and PorY) were putative two-component system regulatory proteins. Real-time RT-PCR analysis revealed that porK, porL, porM, porN, porP, porT, and sov were down-regulated in P. gingivalis porX and porY mutants. Disruption of the F. johnsoniae porT ortholog resulted in defects in motility, chitinase secretion, and translocation of a gliding motility protein, SprB adhesin, to the cell surface, providing a link between a unique protein translocation system and a motility apparatus in members of the Bacteroidetes phylum.

  8. Differential Regulation of Duplicate Light-Dependent Protochlorophyllide Oxidoreductases in the Diatom Phaeodactylum tricornutum

    PubMed Central

    Hunsperger, Heather M.; Cattolico, Rose Ann

    2016-01-01

    Background Diatoms (Bacilliariophyceae) encode two light-dependent protochlorophyllide oxidoreductases (POR1 and POR2) that catalyze the penultimate step of chlorophyll biosynthesis in the light. Algae live in dynamic environments whose changing light levels induce photoacclimative metabolic shifts, including altered cellular chlorophyll levels. We hypothesized that the two POR proteins may be differentially adaptive under varying light conditions. Using the diatom Phaeodactylum tricornutum as a test system, differences in POR protein abundance and por gene expression were examined when this organism was grown on an alternating light:dark cycles at different irradiances; exposed to continuous light; and challenged by a significant decrease in light availability. Results For cultures maintained on a 12h light: 12h dark photoperiod at 200μE m−2 s−1 (200L/D), both por genes were up-regulated during the light and down-regulated in the dark, though por1 transcript abundance rose and fell earlier than that of por2. Little concordance occurred between por1 mRNA and POR1 protein abundance. In contrast, por2 mRNA and POR2 protein abundances followed similar diurnal patterns. When 200L/D P. tricornutum cultures were transferred to continuous light (200L/L), the diurnal regulatory pattern of por1 mRNA abundance but not of por2 was disrupted, and POR1 but not POR2 protein abundance dropped steeply. Under 1200μE m−2 s−1 (1200L/D), both por1 mRNA and POR1 protein abundance displayed diurnal oscillations. A compromised diel por2 mRNA response under 1200L/D did not impact the oscillation in POR2 abundance. When cells grown at 1200L/D were then shifted to 50μE m−2 s−1 (50L/D), por1 and por2 mRNA levels decreased swiftly but briefly upon light reduction. Thereafter, POR1 but not POR2 protein levels rose significantly in response to this light stepdown. Conclusion Given the sensitivity of diatom por1/POR1 to real-time light cues and adherence of por2/POR2 regulation to

  9. The Impact of Regional Differences on Elementary School Teachers' Attitudes towards Their Students' Use of Code Switching in a South Texas School District (El impacto de las diferencias regionales en las actitudes de docentes de primaria respecto a la alternancia de códigos por parte de los estudiantes en un distrito escolar del sur de Texas)

    ERIC Educational Resources Information Center

    Nava Gómez, Guadalupe Nancy; García, Hilda

    2012-01-01

    This study focused on investigating whether the teachers' geographical distribution influences their attitudes towards their students' use of code switching. The study was guided by the following research question: Are there differences between teachers' opinions of the north elementary schools and teachers' opinions of the…

  10. Evaluation de la qualité de modèles numériques de terrain dérivés par interférométrieEvaluación de la calidad de modelos digitales de elevación derivados por interferometría

    NASA Astrophysics Data System (ADS)

    Gens, Rüdiger

    One of the most important uses of SAR interferometry is in the generation of digital elevation models (DEMs). However, a standard procedure for quality estimation of DEMs does not exist. This paper proposes a method of quality estimation using an adapted Monte Carlo simulation, which has the advantage that it could be used in areas where appropriate reference DEMs are not available. This paper also addresses interferometric processing, with special emphasis on the influence of the input parameters. Practical implementation of the proposed technique is shown on a data set from Lower Saxony in Germany. The error map generated, which is a measure of the quality of the DEM, is also presented. For further analysis of the critical aspects of quality, a reference DEM has also been used.

  11. Reading with Children: Activities for Families with Children Ages 3 to 5 [Presented by]"Between the Lions[R]" = La lectura con los ninos: Actividades para familias con ninos de 3 a 5 anos [presentado por]"Between the Lions[R]."

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    "Between the Lions" is a Public Broadcasting System program promoting literacy for children ages 4 through 7 years combining state-of-the-art puppetry, animation, live action, and music to achieve its mission of helping young children learn to read. This guide, in English- and Spanish-language versions, provides literacy activities for parents and…

  12. Lo que los educadores necesitan saber sobre...El agrupamiento por habilidad [y] La compactacion del curriculum [y] Los alumnos dotados y el aprendizaje cooperativo [y] La actividad tutoral. Guias practica (What Educators Need To Know about...Ability Grouping [and] Curriculum Compacting [and] Gifted Students and Cooperative Learning [and] Mentoring. Practitioners' Guides).

    ERIC Educational Resources Information Center

    Siegle, Del, Ed.

    These four pamphlets in Spanish offer guidelines supported by theory-driven quality research that is problem-based, practice-relevant, and consumer-oriented. Each pamphlet has a section summarizing research from the literature or topic notes as well as implications for the classroom. The first guide offers principles for teachers concerning the…

  13. Análisis clínico y epidemiológico de los accidentes por mordeduras de serpientes del género Bothrops en Venezuela [A clinical and epidemiological analysis of accidental bites by snakes of the genus Bothrops in Venezuela].

    PubMed

    Rodríguez Acosta, A; Uzcategui, W; Azuaje, R; Aguilar, I; Girón, M E

    2000-01-01

    Clinical register of 60 patients bitten by Bothrops snake who assisted at Leopoldo Manrique Hospital and the Institute of Tropical Medicine (HLM-IMT) in Caracas during 1996-1997 were analysed. The accident was more frequent in males (45/75%). In 32 cases (53.3%) the snake was classified and 26 were Bothrops lanceolatus, 4 Bothrops venezuelensis and 2 Bothrops atrox. Anatomic regions more frequent bitten were superior members (40/66.6%): hands (36/60%), forearm (2/3.3%), elbow (1/1.6%) and arm (1/1.6%). On inferior members (20/33.3%): legs (6/10%), feet (10/16.7%), ankle (2/3.3%), and the hip (2:3.3%). The most frequent clinical manifestations in moderate and severe cases (33 patient) were pain (100%), oedema (98%), ecchymosis (76%), blisters (20%), necrosis (12%), abscess (6%) bleeding (19%), heart failure (1/1.6%), renal failure (1/1.6%). The blood clotting was evaluated in 60 (100%) cases and it was altered in 33 (55%) patients. No deaths were recorded. PMID:11107900

  14. Words All around Us: Activities for Families with Children Ages 3 to 5 [Presented by]"Between the Lions[R]" = Palabras y palabras a nuestro alrededor: Actividades para familias con ninos de 3 a 5 anos [presentado por]"Between the Lions[R]."

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    "Between the Lions" is a Public Broadcasting System program promoting literacy for children ages 4 through 7 years combining state-of-the-art puppetry, animation, live action, and music to achieve its mission of helping young children learn to read. This guide, in English- and Spanish-language versions, provides literacy activities for parents and…

  15. Art and Writing: Activities for Families with Children Ages 3 to 5 [Presented by]"Between the Lions[R]" = Arte y escritura: Actividades para familias con ninos de 3 a 5 anos [presentado por]"Between the Lions[R]."

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    "Between the Lions" is a Public Broadcasting System program promoting literacy for children ages 4 through 7 years combining state-of-the-art puppetry, animation, live action, and music to achieve its mission of helping young children learn to read. This guide, in English- and Spanish-language versions, provides literacy activities for parents and…

  16. Palabras del Secretario de Educacion Publica en la reunion anual de directores de education federal e inspectores generales en los estados que se rigen por el calendario "A". (Address by the Minister of Education at the Annual Meeting of Directors of Federal Education and Inspectors General in Calendar "A" States).

    ERIC Educational Resources Information Center

    Yanez, Agustin

    This document is an English-language abstract (approximately 1,500 words) of a speech by the Mexican Minister of Education at an annual educators meeting. The Minister dealt with the administration and quality of education, the role of the directors and the duties towards them of the inspectors, and the main features of the reform of national…

  17. Measurement of the branching ratio for the doubly cabibbo suppressed decay D++ K-K+K+; Medida da razao de ramificacao do Decaimento D++ K-K+K+ duplamente suprimido por cabibbo

    SciTech Connect

    Silva Carvalho, Hendly da

    1997-07-01

    In this thesis, we performed a study for the decay modes D++ K-K+K+ and D+s+ K-K+K+, using the data collected by the E791, a hadroproduction of charm experiment at Fermilab. The D++ K-K+K+ decay is doubly Cabibbo suppressed while the D+s+ K-K+K+ decay is singly Cabibbo suppressed. We found 11.6 +- 3.9 events in the D+ mass region and 8.9 +- 3.3 in the D+s mass region. The D++ K-K+K+ branching ratio is measured to be (3.7 +- 1.3 +- 0.6) x 10-4 while the D++ K-K+K+ branching ratio relative to D+s+ K-K+K+ is measured to be (4.2 +- 1.5 +- 0.6) x 10-2.

  18. Por que no dejar a los estudiantes con habilidad superior comenzar la escuela en enero? Estudio de la Compactaction del Curriculum. Monografia Investigativa 94401 (Why Not Let High Ability Students Start School in January? The Curriculum Compacting Study. Research Monograph 94401).

    ERIC Educational Resources Information Center

    Reis, Sally M.; And Others

    This report presents an executive summary, in Spanish, of a study which examined the effects of curriculum compacting, a curriculum modification technique for gifted and talented students. The study involved approximately 436 elementary teachers and 783 students in 27 school districts throughout the United States. The study was designed to…

  19. Los Hispanos: Problemas y Oportunidades. Resumen de la Actual Situacion Demografica, Economica, Social y Politica de los Hispanos en los Estados Unidos y de las Iniciativas Tomadas por la Fundacion Ford Para Hacer Frente a las Necesidades de esta Poblacion en Aumento y Determinar sus Efectos Sobre la Sociedad Estadounidense. Documento de Trabajo de la Fundacion Ford, No. 436.

    ERIC Educational Resources Information Center

    Ford Foundation, New York, NY.

    The Hispanic population's growing impact on American society has caused the Ford Foundation to explore new Foundation initiatives. The 1980 census revealed 14.6 million Hispanics: 60% Mexican American; 14% Puerto Rican; 6% Cuban, and 20% Other. The Hispanic population in the United States is growing and is characterized by diversity; rapid growth…

  20. Análisis clínico y epidemiológico de los accidentes por mordeduras de serpientes del género Bothrops en Venezuela [A clinical and epidemiological analysis of accidental bites by snakes of the genus Bothrops in Venezuela].

    PubMed

    Rodríguez Acosta, A; Uzcategui, W; Azuaje, R; Aguilar, I; Girón, M E

    2000-01-01

    Clinical register of 60 patients bitten by Bothrops snake who assisted at Leopoldo Manrique Hospital and the Institute of Tropical Medicine (HLM-IMT) in Caracas during 1996-1997 were analysed. The accident was more frequent in males (45/75%). In 32 cases (53.3%) the snake was classified and 26 were Bothrops lanceolatus, 4 Bothrops venezuelensis and 2 Bothrops atrox. Anatomic regions more frequent bitten were superior members (40/66.6%): hands (36/60%), forearm (2/3.3%), elbow (1/1.6%) and arm (1/1.6%). On inferior members (20/33.3%): legs (6/10%), feet (10/16.7%), ankle (2/3.3%), and the hip (2:3.3%). The most frequent clinical manifestations in moderate and severe cases (33 patient) were pain (100%), oedema (98%), ecchymosis (76%), blisters (20%), necrosis (12%), abscess (6%) bleeding (19%), heart failure (1/1.6%), renal failure (1/1.6%). The blood clotting was evaluated in 60 (100%) cases and it was altered in 33 (55%) patients. No deaths were recorded.

  1. Mitigation of Disagreement in Peer Review among L2 Learners and Native Speakers in a College Writing Class (Mitigación del Impacto de las Opiniones de Desacuerdo en el Proceso de Revisión por Pares entre Estudiantes de una Segunda Lengua y Hablantes Nativos en una Clase de Escritura a Nivel Universitario)

    ERIC Educational Resources Information Center

    Christoffersen, Katherine O'Donnell

    2015-01-01

    Peer review is now a commonplace practice in process-oriented writing instruction. A crucial aspect of peer review is assessing another classmate's work, which encompasses the act of disagreement. Given its prevalence in the classroom, it is necessary to analyze how L2 learners mitigate disagreement in the context of peer review with other L2…

  2. Talking, Singing, Rhyming: Activities for Families with Children Ages 3 to 5 [Presented by]"Between the Lions[R]" = Hablar, cantar, recitar: Actividades para familias con ninos de 3 a 5 anos [presentado por]"Between the Lions[R]."

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    "Between the Lions" is a Public Broadcasting System program promoting literacy for children ages 4 through 7 years combining state-of-the-art puppetry, animation, live action, and music to achieve its mission of helping young children learn to read. This guide, in English- and Spanish-language versions, provides literacy activities for parents and…

  3. A Visit to the Library: Activities for Families with Children Ages 3 to 5 [Presented by]"Between the Lions[R]" = Una visita a la biblioteca: Actividades para familias con ninos de 3 a 5 anos [presentado por]"Between the Lions[R]."

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    "Between the Lions" is a Public Broadcasting System program promoting literacy for children ages 4 through 7 years combining state-of-the-art puppetry, animation, live action, and music to achieve its mission of helping young children learn to read. This guide, in English- and Spanish-language versions, provides suggestions for parents of 3- to…

  4. For a Child, Life is a Creative Adventure: Supporting Development and Learning through Art, Music, Movement, and Dialogue. A Guide for Parents and Professionals. = Para los ninos, la vida es una aventura creativa: Como estimular el desarrollo y el aprendizaje por medio de las artes visuales, la musica, el movimiento y el dialogo. Guia para padres de familia y profesionales.

    ERIC Educational Resources Information Center

    Cohen, Elena

    Recognizing that creativity facilitates children's learning and development, the Head Start Program Performance Standards require Head Start programs to include opportunities for creative self-expression. This guide with accompanying videotape, both in English- and Spanish- language versions, encourages and assists adults to support children's…

  5. Exploring with Technology: Activities for Families with Children Ages 3 to 5 [Presented by]"Between the Lions[R]" = Exploremos con tecnologia: Actividades para familias con ninos de 3 a 5 anos [presentado por]"Between the Lions[R]."

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    "Between the Lions" is a Public Broadcasting System program promoting literacy for children ages 4 through 7 years combining state-of-the-art puppetry, animation, live action, and music to achieve its mission of helping young children learn to read. This guide, in English- and Spanish-language versions, provides computer literacy activities for…

  6. Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and trace metals in the blood of nonoccupationally exposed residents living in the vicinity of a municipal solid waste incinerator and electric arc furnace.

    PubMed

    Chen, Yan-Min; Lin, Yuan-Chung; Wu, Tzi-Yi; Chang-Chien, Guo-Ping; Ma, Wen-Feng

    2010-06-01

    This study examines levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and trace metals in the blood of the nonoccupationally exposed residents living in the vicinity of municipal solid waste incinerators (MSWIs) and electric arc furnaces (EAFs). The analysis found that older females had higher concentrations of PCDD/Fs and older males had higher body mass index (BMI) values and higher concentrations of PCDD/Fs. Moreover, sex appeared to affect the levels of PCDD/Fs because, overall, females showed higher levels of PCDD/Fs. The results of a principal component analysis indicated that the characteristics of the blood were more similar to the characteristics of the stack flux gas in MSWIs than those in EAFs. When sex, age, and BMI values were taken into consideration, none of the factors appeared to significantly affect PCDD/F and trace metal blood levels. However, when participants were divided into eight categories and analyzed, it was found that sex was the most important factor affecting levels of trace metals in blood and that males had higher concentrations of Pb, Al, Cd, and Cu.

  7. The TOMPs ambient air monitoring network - Continuous data on UK air quality for over 20 years.

    PubMed

    Graf, Carola; Katsoyiannis, Athanasios; Jones, Kevin C; Sweetman, Andrew J

    2016-10-01

    Long-term air monitoring datasets are needed for persistent organic pollutants (POPs) to assess the effectiveness of source abatement measures and the factors controlling ambient levels. The Toxic Organic Micro Pollutants (TOMPs) Network, which has operated since 1991, collects ambient air samples at six sites across England and Scotland, using high-volume active air samplers. The network provides long-term ambient air trend data for a range of POPs at both urban and rural locations. Data from the network provides the UK Government, regulators and researchers with valuable information on emission/source controls and on the effectiveness of international chemicals regulation such as the Stockholm Convention and UN/ECE Protocol on POPs. The target chemicals of TOMPs have been polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and, since 2010, polybrominated diphenyl ethers (PBDEs). The continuous monitoring of these compounds demonstrates the constant decline in UK air concentrations over the last two decades, with average clearance rates for PCDD/Fs in urban locations of 5.1 years and for PCBs across all sites 6.6 years. No significant declines in rural locations for PCDD/Fs have been observed. There is a strong observable link between the declining ambient air concentrations and the emission reductions estimated in the annually produced National Atmospheric Emission Inventory (NAEI) dataset. These findings clearly demonstrate the unique strengths of long-term consistent datasets for the evaluation of the success of chemical regulation and control.

  8. Hydrothermal treatment of municipal solid waste incineration fly ash for dioxin decomposition.

    PubMed

    Hu, Yuyan; Zhang, Pengfei; Chen, Dezhen; Zhou, Bin; Li, Jianyi; Li, Xian-Wei

    2012-03-15

    Hydrothermal treatment of MSWI fly ash was performed in this paper with a purpose to reduce its dioxin content. First a hydrothermal reactor was set up with a mixture of ferric sulphate and ferrous sulphate serviced as the reactant, then the effects caused by reaction conditions such as reaction temperature, pre-treatment by water-washing and reactant dosage were checked; the results showed that as a promising technology, hydrothermal treatment exhibited considerable high efficiencies in decomposition of PCDDs/PCDFs and good stabilization of heavy metals as well. Experimental results also showed that for dioxin destruction, higher reaction temperature is the most important influencing factor followed by Fe addition, and pre-treatment of raw fly ash by water-washing increased the destruction efficiencies of dioxins only very slightly. Finally with help of Gaussian software chemical computational simulation was performed to investigate the mechanism of dioxin decomposition based on quantum chemistry calculation. The calculation results were supported by the experimental data. The leaching toxicities of hydrothermal products were higher than upper limits defined in the latest Chinese standard GB 16889-2008 for sanitary landfill disposal, thus an auxiliary process is suggested after the hydrothermal treatment for heavy metal stabilization. PMID:21680088

  9. Comparative study on PCDD/F pollution in soil from the Antarctic, Arctic and Tibetan Plateau.

    PubMed

    Jia, Shenglan; Wang, Qiang; Li, Li; Fang, Xuekun; Shi, Yehong; Xu, Weiguang; Hu, Jianxin

    2014-11-01

    The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in 35 soil samples collected from Fildes Peninsula in the Antarctic, Ny-Ålesund in the Arctic, and Zhangmu-Nyalam in the Tibetan Plateau were reported in this study. A comparison of the total concentration and TEQ of PCDD/Fs at the Three Poles was conducted. Both the total concentration and TEQ of PCDD/Fs demonstrates a decreasing trend in the order of Zhangmu-Nyalam (mean: 26.22 pg/g, 0.37 pg I-TEQ/g)>Ny-Ålesund (mean: 9.97 pg/g, 0.33 pg I-TEQ/g)>Fildes Peninsula (mean: 2.18 pg/g, 0.015 pg I-TEQ/g) (p<0.05). In all samples, the congener and homologue profiles dominated with higher (seven and eight) chlorinated PCDD/Fs (more than 85% of the total mass percentage of PCDD/Fs) at the Three Poles. Finally, a FLEXPART backward simulation was used to preliminarily identify the potential local and regional anthropogenic sources of PCDD/Fs. The results imply that the air masses passing over surrounding regions with significant PCDD/F emissions might contribute to the occurrence of PCDD/Fs in both the Arctic and Tibetan Plateau.

  10. Assessing influence of experimental parameters on formation of PCDD/F from ash derived from fires of CCA-treated wood.

    PubMed

    Tame, N W; Dlugogorski, B Z; Kennedy, E M

    2003-09-15

    Ash residues from fires of radiata pine timber, both untreated and treated with chromated copper arsenate (CCA), were analyzed for the presence of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F). Fire conditions were simulated using a cone calorimeter. The sensitivity of the magnitude and profile of PCDD/F in the ash under controlled experimental conditions were examined to gain an insight into the formation of PCDD/F in a system containing CCA. The total amount of PCDD/F increased from 2.0 ng/kg of ash (0.05 ng of TE/kg of ash, using WHO-TEF) for untreated radiata pine to a maximum of 2700 ng/kg of ash (78 ng of TE/kg of ash) for 0.94% CCA. Ash containing CCA showed a distinct preference for formation of PCDFs, particularly the tetrachloro homologue. It is concluded that PCDD/F formation predominantly occurred via de novo synthesis during smoldering of the char rather than during the initial flaming and pyrolysis. Furthermore, the composition of the CCA constituents present in the timber was controlled to assess whether the physical presence of Cu, a known catalyst in PCDD/F production, was sufficient to account for the formation of PCDD/F in fires of timber impregnated with CCA. PMID:14524447

  11. Synergetic inhibition of thermochemical formation of chlorinated aromatics by sulfur and nitrogen derived from thiourea: Multielement characterizations.

    PubMed

    Fujimori, Takashi; Nakamura, Madoka; Takaoka, Masaki; Shiota, Kenji; Kitajima, Yoshinori

    2016-07-01

    Nitrogen and sulfur (N/S)-containing compounds inhibit the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs) in thermal processes. However, few studies have examined the inhibition mechanisms of N/S-containing compounds. In the present study, we focused on thiourea [(NH2)2CS] as such a compound and investigated its inhibition effects and mechanisms. The production of PCDD/Fs, polychlorinated biphenyls (PCBs), and chlorobenzenes (CBzs) were inhibited by >99% in the model fly ash in the presence of 1.0% thiourea after heating at 300 °C. Experimental results using real fly ash series were indicative of the thermal destruction of these chlorinated aromatics by thiourea. Multielement characterization using K-edge X-ray absorption fine structures of copper, chlorine, sulfur, nitrogen, and carbon revealed three possible inhibition paths, namely, (a) sulfidization of the copper catalyst to CuS, Cu2S, and CuSO4; (b) blocking the chlorination of carbon via the reaction of chlorine with N-containing compounds to generate ammonium chloride and other minor compounds; and (c) changing the carbon frame involved in attacking the carbon matrix by sulfur and nitrogen. Thus, thiourea plays a role as a sulfur and nitrogen donor to achieve multiple and synergistic inhibition of chlorinated aromatics. Our results suggest that other N/S-containing inhibitors function based on similar mechanisms.

  12. Kinetics of PCDD/Fs formation from non-wood pulp bleaching with chlorine.

    PubMed

    Wang, Xueli; Zhang, Haijun; Ni, Yuwen; Du, Qinqin; Zhang, Xueping; Chen, Jiping

    2014-04-15

    Chlorine bleaching is still practiced by most of nonwood pulp and paper mills, resulting in a considerable amount of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) formation and emission. In this study, the effects of primary chlorination conditions on the formation of PCDD/Fs from nonwood pulp bleaching with elemental chlorine were investigated. It was found that low-chlorinated PCDD/Fs were usually formed and then underwent further chlorination to form highly chlorinated PCDD/Fs with increasing chlorination time. Higher available chlorine dosages and lower system pH values greatly accelerated dioxin formation, and pH 3 was the threshold for the formation of tetra- to octa-CDD/Fs. Higher temperatures promoted the formation of lower-chlorinated PCDD/Fs, while caused significant reduction of tetra- to hepta-CDDs and penta- to octa-OCDFs. PCDFs were formed much faster than PCDDs. A first-order kinetic model showed a good fit to the data for tetra- to oct-CDFs formation under different chlorination conditions, indicating that chlorine substitution was the rate determining step for their formation. Finally, the optimum chlorination conditions for minimizing and eliminating the formation of 2,3,7,8-TCDD/TCDF in nonwood pulp bleaching with elemental chlorine were established.

  13. Osprey distribution, abundance, reproductive success and contaminant burdens along lower Columbia River, 1997/1998 versus 2004.

    PubMed

    Henny, C J; Grove, R A; Kaiser, J L

    2008-04-01

    The osprey (Pandion haliaetus) population nesting along the lower portion of the Columbia River (river mile 29 to 286) increased from 94 in 1997 to 103 occupied nests in 1998 (9.6% annual rate of increase) to 225 occupied nests in 2004 (13.9% annual rate of increase). The more recent rate of population increase was associated with higher reproductive rates than in 1997/1998, and significantly lower egg concentrations of most organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). A comparison of observed egg residue concentrations in 2004 with effect-level information for ospreys indicated that reproduction at few, if any, nests was adversely affected. As recent as 1997/1998, dichlorodiphenyldichloroethylene (DDE) was still adversely affecting reproductive success for a portion of this population. Mercury was the only contaminant evaluated in both 1997/1998 and 2004 that showed a significant increase in eggs over time, but concentrations in 2004 (0.09 microg g(-1) ww) remained below established effect levels for birds (generally reported at 0.50 microg g(-1) ww or higher). The significant increase in mercury justifies the need for future monitoring. All contaminants mentioned that biomagnify up food chains can be effectively monitored in osprey eggs. The osprey has been shown to be an excellent sentinel species for long-term monitoring with their many useful traits described.

  14. Endocrine disrupting chemicals-Linking internal exposure to vitellogenin levels and ovotestis in Abramis brama from Dutch surface waters.

    PubMed

    Reinen, Jelle; Suter, Marc J-F; Vögeli, A Christiane; Fernandez, Mariana F; Kiviranta, Hannu; Eggen, Rik I L; Vermeulen, Nico P E

    2010-11-01

    The exposure of male bream from three Dutch freshwater locations to endocrine disrupting compounds (EDCs) and corresponding effects are described in this study. Fish specimen displaying reproductive disorders associated with high levels of plasma vitellogenin (VTG) concentrations and occurrence of ovotestis (OT) were investigated. To provide information on the full spectrum of EDCs in fish tissue, adipose tissue samples of individual fish were analyzed for nearly 130 chemicals targeting different compound classes (bisphenols, alkylphenols, pesticides, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), hydroxylated polychlorinated biphenyls (OH-PCBs), polybrominated diphenyl ethers (PBDEs) and biphenyls (PBBs)) and steroid hormones. To establish whether tissue from specimen with reproductive disorders shows a spectrum of EDCs that is qualitatively and quantitatively different from that of controls free of symptoms, bioassay-directed fractionation was performed using the recombinant yeast estrogen screen (YES), the E-Screen bioassay, the human sulfotransferase 1E1 (SULT1E1) inhibition assay, and the coumestrol-based estrogen receptor α (ERα) high resolution screening (HRS) assay. No differences in estrogenicity could be observed between the cases and controls and steroidal estrogens accounted for the majority of estrogenicity found in the complex mixtures. In this study, the combination of the different assays employed to measure total estrogenicity and the SULT1E1 inhibition does not predict the outcome of unwanted physiological effects, however, it can be used to determine the presence of EDCs in fish samples and their estrogenic effects. PMID:21787654

  15. Determination of levels of persistent organic pollutants (PCDD/Fs, PBDD/Fs, PBDEs, PCBs, and PBBs) in atmosphere near a municipal solid waste incinerator.

    PubMed

    Wang, Mao-Sung; Chen, Shui-Jen; Huang, Kuo-Lin; Lai, Yi-Chieh; Chang-Chien, Guo-Ping; Tsai, Jen-Hsiung; Lin, Wen-Yinn; Chang, Kuo-Ching; Lee, Jia-Twu

    2010-08-01

    This work develops a comprehensive approach for quantitatively analyzing polychlorinated and polybrominated dibenzo-p-dioxins (PCDDs/PBDDs), dibenzofurans (PCDFs/PBDFs), biphenyls (PCBs/PBBs) and diphenyl ethers (PBDEs). This technique, based on multiple (silica, alumina, and active carbon) columns, can be applied to prepare samples for determining the five group compounds based on high-resolution gas chromatography/high-resolution mass spectrometry. The method was also validated by analyses of blank and spiked samples. In the sampled air, the mean PCDD/F, PCB, PBDD/F, PBDE, and PBB concentrations were 59.6 fg WHO-TEQ Nm(-3), 6.74 fg WHO-TEQ Nm(-3), 12.2 fg WHO-TEQ Nm(-3), 52100 fg Nm(-3), and 341 fg Nm(-3), respectively. The WHO-TEQ of dioxin-like PCB and PBDD/Fs counted for 8.9% and 16% of total TEQ (summed over PCDD/Fs, PBDD/Fs, and dioxin-like PCBs), respectively, suggesting that the atmospheric concentrations of dioxin and dioxin-like compounds should be regulated together because of the persistence and toxicity of PBDD/Fs and dioxin-like PCBs. PMID:20598339

  16. Infant exposure assessment for breast milk dioxins and furans derived from waste incineration emissions

    SciTech Connect

    Smith, A.H.

    1987-09-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) have been detected in human milk samples obtained in several countries. Possible sources include emissions from incineration of municipal waste in resource recovery facilities. A formula is presented for calculating the infant daily dose of dioxin equivalents from breast milk on the basis of the maternal daily intake. Application of the formula suggests that an infant breast-fed for 12 months would receive around 10% of the cumulative exposure dose per body weight that would be received by an adult with 50 years of exposure. Further analysis indicated that the contribution of dioxin equivalents from breast milk to an infant's body concentration at the end of 12 months of breast feeding would amount to 1.7 times the concentration in the mother. However, dioxin and furan emissions from a source calculated to result in worst-case lifetime cancer risks of the order of 1 in 100,000 are only likely to increase breast milk concentrations by around 1%-10% of the levels that have been detected in several countries. This finding suggests that there are major sources of dioxins and furans other than from municipal solid waste incineration that need to be identified.

  17. PCDD/PCDF Ratio in the Precursor Formation Model over CuO Surface

    PubMed Central

    2015-01-01

    The discrepancies between polychlorinated dibenzo-p-dioxin to polychlorinated dibenzofuran (PCDD to PCDF) ratios in laboratory and field studies in the exhaust of combustion sources are not fully explained by available formation models. In this paper we present the results of experimental studies of the surface mediated formation of PCDD/F at the conditions mimicking the combustion cool zone from a mixture of 1,2-dichlorobenzene (1,2-DCBz) and 2-monochlorophenol (2-MCP) over a model surface consisting of 5% CuO/Silica. The PCDD to PCDF ratio was found to be strongly dependent on the ratio of chlorinated benzenes to chlorinated phenols and oxygen content. The higher the 1,2-DCBz to 2-MCP ratio, the lower the PCDD to PCDF ratio. PCDFs are formed predominantly from chlorinated benzenes, while chlorinated phenols are responsible for majority of PCDDs. These laboratory results are in general agreement with full-scale measurement and can be used to improve predictive models of PCDD/F formation. PMID:25372621

  18. Multi-level detection of toxic stress in the mudpuppy (amphibian, salamander)

    SciTech Connect

    Gendron, A.D.; Fortin, R.; Hontela, A.; Bishop, C.A.; Van Der Kraak, G.

    1994-12-31

    Worldwide reports of declining amphibian populations highlight the need for ecotoxicological research on amphibians. The authors have investigated the response to toxic stress in the mudpuppy. Sites (N = 9) along mixed pollution gradients in the St. Lawrence/Ottawa Rivers systems were sampled on two consecutive winters (1992-93). Elevated concentrations of organochlorine pesticides, PCBs, and PCDFs detected in female gonads at the most contaminated sites, led the investigation toward signs of reproductive dysfunction. High levels of skeletal deformities were observed in the most polluted group where mudpuppies were found significantly more at risk to develop limb defects than at the reference site. The frequencies of terata, including oligodactyly and polydactyly, significantly increased with the intensity of exposure to recognized teratogens, in the St. Lawrence River system. The finding of deformities in adults could signal a more important impact during early life stages. The shift toward older t the most impacted site suggest a decrease in recruitment, that is consistent with lower survival of embryos developing under a toxic stress. Among site differences in other indicators of reproductive performance such as fecundity, gonado-somatic indices, circulating levels of 17{beta}-estradiol, testosterone, and corticosterone in females with vitellogenic eggs, were not detected.

  19. Thermally induced formation of polychlorinated dibenzofurans from Aroclor 1254-contaminated mineral oil.

    PubMed Central

    Narang, R S; Swami, K; Stein, V; Smith, R; O'Keefe, P; Aldous, K; Hilker, D; Eadon, G; Vernoy, C; Narang, A S

    1989-01-01

    Numerous laboratory simulations and real-world events have demonstrated the thermal conversion of neat or high concentration of PCBs into the much more toxic PCDFs. Since millions of mineral oil transformers currently in service contain PCB concentrations in the 50 to 5000 ppm range, the thermal behavior of dilute PCB solutions is of practical and regulatory significance. In this work, neat Aroclor 1254 and 5000 ppm Aroclor 1254 in mineral oil were subjected to pyrolysis and combustion under a range of experimental conditions to define parameters resulting in maximal PCDF yields. The dependence of PCDF yield on Aroclor 1254 concentrations was then investigated in the 5000 to 50 ppm range. Combustion experiments demonstrated that PCDF yields expressed as micrograms PCDF/gram PCB were independent of concentration range, confirming that the process is kinetically first order in PCB. Much lower yields of PCDF were observed in the open tube pyrolysis experiments, as compared to combustion experiments and to earlier and concurrent sealed tube experiments. Slightly improved yields were observed in the pyrolysis experiments at lower concentrations, suggesting the existence of a PCB or PCDF destruction process of higher than first order kinetics. In all cases, yields expressed as micrograms PCDF/gram mixture were sharply and monotonically lower as concentrations decreased between neat or 5000 ppm Aroclor 1254 and 50 ppm Aroclor 1254. PMID:2495933

  20. Influence of organic and inorganic flocculants on the formation of PCDD/Fs during sewage sludge incineration.

    PubMed

    Lin, Xiaoqing; Li, Xiaodong; Lu, Shengyong; Wang, Fei; Chen, Tong; Yan, Jianhua

    2015-10-01

    Flocculants are widely used to improve the properties of sludge dewatering in industrial wastewater treatment. However, there have been no studies conducted on the influence of flocculants on the formation of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) during sewage sludge incineration. This paper selected three typical kinds of flocculants, including polyacrylamide (PAM), poly-ferric chloride (PFC), and polyaluminum chloride (PAC) flocculant, to study their influences on the formation of PCDD/Fs during sewage sludge incineration. The results indicated that PAM flocculant, which is an organic flocculant, inhibited the formation of PCDD/Fs in sewage sludge incineration, while inorganic flocculant, such as PFC and PAC flocculant, promoted the formation. The most probable explanation is that the amino content in the PAM flocculant acted as an inhibitor in the formation of PCDD/Fs, while the chlorine content, especially the metal catalyst in the PFC and PAC flocculants, increased the formation rate. The addition of flocculants nearly did not change the distribution of PCDD/F homologues. The PCDFs contributed the most toxic equivalent (TEQ) value, especially 2, 3, 4, 7, 8-PeCDF. Therefore, the use of inorganic flocculants in industrial wastewater treatment should be further assessed and possibly needs to be strictly regulated if the sludge is incinerated. From this aspect, a priority to the use of organic flocculants should be given.