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Sample records for lead exposure stimulates

  1. DETERMINANTS OF RESIDENTIAL LEAD EXPOSURE

    EPA Science Inventory

    The phase-out of leaded gasoline, and the accompanying decrease in lead emissions, resulted in a dramatic decline in mean blood lead levels from the late 1970s through the early 1990s. Nonetheless, lead exposures remain a public health concern. Long-term exposures to even low...

  2. Effects of occupational lead exposure.

    PubMed

    Wang, Y L; Lu, P K; Chen, Z Q; Liang, Y X; Lu, Q M; Pan, Z Q; Shao, M

    1985-01-01

    Fifty-three workers in a battery factory, 52 solderers in a television factory, and 50 embroidery workers (a reference group) were studied. The average air lead levels of the three workplaces were 0.578 mg/m3, 0.002 mg/m3, and 0.001 mg/m3, respectively. Adverse effects in terms of clinical manifestations and biochemical criteria were evident among the battery factory workers. A significant dose-response relationship existed between the toxic effects and the air lead levels. The solderers showed no apparent abnormalities in comparison with the embroidery workers. The early clinical manifestations were dysfunction of the central nervous system, indigestion, arthralgia, and myalgia in the extremities. A positive association was observed between the prevalence of fatigue, mild abdominal pain, and arthralgia and the blood lead (PbB), urinary lead (PbU), and zinc protoporphyrin (ZPP) levels. The symptomatic threshold values of PbB, PbU, and ZPP were 30 micrograms/dl (1.5 mumol/l), 0.045 mg/l (0.2 mumol/l), and 40 micrograms/dl (0.7 mumol/l), respectively. The PbB, PbU, free erythrocyte protoporphyrin, and ZPP levels and the blood aminolevulinic dehydratase ratio could be used as indicators of lead exposure, although ZPP is preferred for a preventive monitoring program. The motor and sensory conduction velocities of the median nerve were slower in the exposed groups than in the reference group. No effects on behavioral function were observed among the solderers. PMID:3832431

  3. Lead exposure at uncovered outdoor firing ranges

    SciTech Connect

    Goldberg, R.L.; Hicks, A.M.; O'Leary, L.M.; London, S. )

    1991-06-01

    Excessive lead exposure in shooting instructors at indoor firing ranges and covered outdoor firing ranges has been documented. The City of Los Angeles assessed exposure of its full-time shooting instructors at uncovered outdoor ranges via air monitoring and blood lead-level measurements. Results of these tests revealed that significant lead exposure and absorption can occur at outdoor firing ranges. The use of copper-jacketed ammunition may decrease air lead levels and decrease lead absorption by range instructors.

  4. Vestibular stimulation leads to distinct hemodynamic patterning

    NASA Technical Reports Server (NTRS)

    Kerman, I. A.; Emanuel, B. A.; Yates, B. J.

    2000-01-01

    Previous studies demonstrated that responses of a particular sympathetic nerve to vestibular stimulation depend on the type of tissue the nerve innervates as well as its anatomic location. In the present study, we sought to determine whether such precise patterning of vestibulosympathetic reflexes could lead to specific hemodynamic alterations in response to vestibular afferent activation. We simultaneously measured changes in systemic blood pressure and blood flow (with the use of Doppler flowmetry) to the hindlimb (femoral artery), forelimb (brachial artery), and kidney (renal artery) in chloralose-urethane-anesthetized, baroreceptor-denervated cats. Electrical vestibular stimulation led to depressor responses, 8 +/- 2 mmHg (mean +/- SE) in magnitude, that were accompanied by decreases in femoral vasoconstriction (23 +/- 4% decrease in vascular resistance or 36 +/- 7% increase in vascular conductance) and increases in brachial vascular tone (resistance increase of 10 +/- 6% and conductance decrease of 11 +/- 4%). Relatively small changes (<5%) in renal vascular tone were observed. In contrast, electrical stimulation of muscle and cutaneous afferents produced pressor responses (20 +/- 6 mmHg) that were accompanied by vasoconstriction in all three beds. These data suggest that vestibular inputs lead to a complex pattern of cardiovascular changes that is distinct from that which occurs in response to activation of other types of somatic afferents.

  5. STUDIES IN SUBCLINICAL LEAD EXPOSURE

    EPA Science Inventory

    The study was initiated to examine the utility of neuropsychologic testing in identifying deficits in children with asymptomatic elevations in blood lead levels. From the files of the Boston Lead Screening Project the authors selected black male children between the ages of six a...

  6. Fetal lead exposure: antenatal factors

    SciTech Connect

    Ernhart, C.B.; Wolf, A.W.; Sokol, R.J.; Brittenham, G.M.; Erhard, P.

    1985-10-01

    It was hypothesized that maternal blood lead level at delivery and cord blood lead level of the neonate would be affected by maternal use of alcohol, history of alcohol abuse, and smoking. The possibility that iron status, as reflected in maternal serum ferritin, would be related to lead level was also explored. The maternal history of alcohol abuse was unrelated to lead level in 208 samples of maternal blood and 178 samples of cord blood. However, alcohol use during pregnancy was related in a dose-response fashion to maternal and to cord blood lead level. This effect was significant with and without control of maternal smoking. The effect of maternal smoking and serum thiocyanate on maternal and cord blood lead level were also highly significant with and without control of the maternal drinking variable. Serum ferritin was marginally related to lead level for white women and for black infants, but tests of the dichotomized maternal ferritin variable did not yield a significant linkage with maternal or cord blood lead level. The results further support recommendations that women abstain from alcohol consumption and cigarette smoking in pregnancy.

  7. Evaluation and management of lead exposure.

    PubMed

    Kim, Hwan-Cheol; Jang, Tae-Won; Chae, Hong-Jae; Choi, Won-Jun; Ha, Mi-Na; Ye, Byeong-Jin; Kim, Byoung-Gwon; Jeon, Man-Joong; Kim, Se-Yeong; Hong, Young-Seoub

    2015-01-01

    Lead, which is widely used in industry, is a common element found in low concentrations in the Earth's crust. Implementations to reduce environmental lead concentrations have resulted in a considerable reduction of lead levels in the environment (air) and a sustained reduction in the blood lead levels of the average citizen. However, people are still being exposed to lead through a variety of routes in everyday commodities. Lead causes health problems such as toxicity of the liver, kidneys, hematopoietic system, and nervous system. Having a carcinogenic risk as well, the IARC classifies inorganic lead compounds as probably carcinogenic to humans (Group 2A). Occupational lead poisonings have decreased due to the efforts to reduce the lead concentrations in the working environment. In contrast, health hazards associated with long-term environmental exposure to low concentrations of lead have been reported steadily. In particular, chronic exposure to low concentrations of lead has been reported to induce cognitive behavioral disturbances in children. It is almost impossible to remove lead completely from the human body, and it is not easy to treat health hazards due to lead exposure. Therefore, reduction and prevention of lead exposure are very important. We reviewed the toxicity and health hazards, monitoring and evaluation, and management of lead exposure. PMID:26677413

  8. Human lead metabolism: Chronic exposure, bone lead and physiological models

    NASA Astrophysics Data System (ADS)

    Fleming, David Eric Berkeley

    Exposure to lead is associated with a variety of detrimental health effects. After ingestion or inhalation, lead may be taken up from the bloodstream and retained by bone tissue. X-ray fluorescence was used to make in vivo measurements of bone lead concentration at the tibia and calcaneus for 367 active and 14 retired lead smelter workers. Blood lead levels following a labour disruption were used in conjunction with bone lead readings to examine the endogenous release of lead from bone. Relations between bone lead and a cumulative blood lead index differed depending on time of hiring. This suggests that the transfer of lead from blood to bone has changed over time, possibly as a result of varying exposure conditions. A common polymorphism in the δ-aminolevulinate dehydratase (ALAD) enzyme may influence the distribution of lead in humans. Blood lead levels were higher for smelter workers expressing the more rare ALAD2 allele. Bone lead concentrations, however, were not significantly different. This implies that a smaller proportion of lead in blood is distributed to tissue for individuals expressing the ALAD2 allele. The O'Flaherty physiological model of lead metabolism was modified slightly and tested with input from the personal exposure histories of smelter workers. The model results were consistent with observation in tern of endogenous exposure to lead and accumulation of lead in cortical bone. Modelling the calcaneus as a trabecular bone site did not reproduce observed trends. variations in lead metabolism between different trabecular sites may therefore be significant. The model does not incorporate a genetic component, and its output did not reflect observed differences in this respect. This result provides further support for the influence of the ALAD polymorphism on lead metabolism. Experimental trials with a digital spectrometer revealed superior energy resolution and count throughput relative to the conventional X-ray fluorescence system. The associated

  9. International perspectives of lead exposure and lead toxicity.

    PubMed

    Grandjean, P

    1993-01-01

    Three approaches have been used to examine how human body burdens of lead depend on different environments: (1) In paleopathologic studies, lead concentrations have been determined in well-preserved human bones or teeth, and pre-pollution samples generally show lead concentrations of about 1% of current levels in industrialized countries. (2) Geographic comparisons of blood-lead concentrations show low levels in, Nepal, Faroe Islands, and Sweden, while high levels occur in Mexico and Malta; average blood-lead levels may vary by a factor of 10 or more. (3) In analytical epidemiology, major exposure sources have been related to lead levels in blood, by either prospective or cross-sectional design. Increased blood-lead concentrations are related to smoking, drinking alcoholic beverages, eating vegetables for dinner, urban residence, and exposure from lead-using industries; average blood-lead values of subgroups within well-defined populations may vary by a factor of 3 or more. The dose-relationships for lead-induced neurotoxicity will depend on the sensitivity of the parameters chosen as indicators of lead exposure and of neurotoxicity. The temporal relationship between lead exposures and the development of deficits must be ascertained. Individual susceptibility and interacting factors must also be taken into account. Differences in addressing these issues impede the comparison between studies. Recently neonatal jaundice has been found to be a risk factor for subsequent neurobehavioral dysfunction in children with a birth weight above 2500 g, but only in children with increased lead exposure. Lead exposure may act in combination with several other factors and result in additive, or synergistic effects.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8247415

  10. Lead absorption in cows: biological indicators of ambient lead exposure

    SciTech Connect

    Karacic, V.; Prpic-Majic, D.; Skender, L.

    1984-03-01

    In order to determine actual lead exposure from residual amounts of lead in the environmental soil following the introduction of effective engineering emission controls in a lead smeltery, the absorption of lead in cows grazing in the vicinity was investigated. Four groups of cows were examined: two groups of cows exposed to different ambient lead concentration, compared with two normal groups of cows. In each cow aminolevulinic acid dehydratase (ALAD), erythrocyte protoporphyrin (EP) and blood lead (Pb-B) were determined, two years prior to and four years after the technical sanitation of the lead emission source. The results demonstrated normalization of ALAD, EP and Pb-B after the technical sanitation. In spite of normalization, biological indicators ALAD and Pb-B determined four years after the technical sanitation showed increased lead absorption in comparison with the results of the control group. This indirectly indicates lead contamination of the environment from residual amounts of lead in the soil.

  11. DIETARY EXPOSURE OF CHILDREN TO LEAD

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because 1) they have more opportunity for contact with lead sources due to their activities, 2) lead adsorption occurs more readily in a child as compared to an adult, and 3) the child's development is more vulnerable ...

  12. Lead exposure causes thyroid abnormalities in diabetic rats

    PubMed Central

    Zadjali, Salah Al; Nemmar, Abderrahim; Fahim, Mohamed Abdelmonem AY; Azimullah, Sheikh; Subramanian, Dhanasekaran; Yasin, Javed; Amir, Naheed; Hasan, Mohammed Yousif; Adem, Abdu

    2015-01-01

    Lead is a widely-spread environmental pollutant and a commonly-used industrial chemical that can cause multisystemic adverse health effects. However, the effects of lead exposure on diabetic animals have not been reported so far. The aim of this study is to evaluate the effects of lead exposure on thyroid, renal and oxidative stress markers in diabetic Wistar rats. Diabetes was induced with an intraperitoneal (i.p.) injection of streptozocin (STZ). Six weeks later, rats were exposed i.p. to either distilled water (control group) or 25, 50 and 100 mg/kg of lead acetate (treatment groups). We found a positive relationship between the administered doses of lead acetate and its measured levels in blood samples (P < 0.01). Treatment of diabetic animals with lead acetate resulted in significant weight loss (P < 0.001). It also caused an increase in thyroid stimulating hormone levels (P < 0.05) and reductions in thyroxine (P < 0.05) and triiodothyronine levels (P < 0.01), a clinical picture consistent with hypothyroidism. Lead acetate exposure increased urea levels (P < 0.05) and caused a significant decrease in creatinine (P < 0.05). Besides, while the concentrations of malondialdehyde were not affected, glutathione stores were depleted (P < 0.01); in response to lead exposure. In conclusion, exposure of diabetic rats to lead acetate resulted in weight loss, clinical hypothyroidism, renal damage and oxidative stress. PMID:26221254

  13. Lead exposure causes thyroid abnormalities in diabetic rats.

    PubMed

    Zadjali, Salah Al; Nemmar, Abderrahim; Fahim, Mohamed Abdelmonem Ay; Azimullah, Sheikh; Subramanian, Dhanasekaran; Yasin, Javed; Amir, Naheed; Hasan, Mohammed Yousif; Adem, Abdu

    2015-01-01

    Lead is a widely-spread environmental pollutant and a commonly-used industrial chemical that can cause multisystemic adverse health effects. However, the effects of lead exposure on diabetic animals have not been reported so far. The aim of this study is to evaluate the effects of lead exposure on thyroid, renal and oxidative stress markers in diabetic Wistar rats. Diabetes was induced with an intraperitoneal (i.p.) injection of streptozocin (STZ). Six weeks later, rats were exposed i.p. to either distilled water (control group) or 25, 50 and 100 mg/kg of lead acetate (treatment groups). We found a positive relationship between the administered doses of lead acetate and its measured levels in blood samples (P < 0.01). Treatment of diabetic animals with lead acetate resulted in significant weight loss (P < 0.001). It also caused an increase in thyroid stimulating hormone levels (P < 0.05) and reductions in thyroxine (P < 0.05) and triiodothyronine levels (P < 0.01), a clinical picture consistent with hypothyroidism. Lead acetate exposure increased urea levels (P < 0.05) and caused a significant decrease in creatinine (P < 0.05). Besides, while the concentrations of malondialdehyde were not affected, glutathione stores were depleted (P < 0.01); in response to lead exposure. In conclusion, exposure of diabetic rats to lead acetate resulted in weight loss, clinical hypothyroidism, renal damage and oxidative stress. PMID:26221254

  14. Occupational lead exposure aboard a tall ship

    SciTech Connect

    Landrigan, P.J.; Straub, W.E.

    1985-01-01

    To evaluate occupational exposures to lead in shipfitters cutting and riveting lead-painted iron plates aboard an iron-hulled sailing vessel, the authors conducted an environmental and medical survey. Lead exposures in seven personal (breathing zone) air samples ranged from 108 to 500 micrograms/mT (mean 257 micrograms/mT); all were above the Occupational Safety and Health Administration (OSHA) standard of 50 micrograms/mT. In two short-term air samples obtained while exhaust ventilation was temporarily disconnected, mean lead exposure rose to 547 micrograms/mT. Blood lead levels in ten shipfitters ranged from 25 to 53 micrograms/dl. Blood lead levels in shipfitters were significantly higher than in other shipyard workers. Smoking shipfitters had significantly higher lead levels than nonsmokers. Lead levels in shipfitters who wore respirators were not lower than in those who wore no protective gear. Four shipfitters had erythrocyte protoporphyrin (EP) concentrations above the adult upper normal limit of 50 micrograms/dl. A close correlation was found between blood lead and EP levels. Prevalence of lead-related symptoms was no higher in shipfitters than in other workers. These data indicate that serious occupational exposure to lead can occur in a relatively small boatyard.

  15. Occupational lead exposure and blood pressure.

    PubMed Central

    Parkinson, D K; Hodgson, M J; Bromet, E J; Dew, M A; Connell, M M

    1987-01-01

    Recent community studies have suggested that low level lead exposure is significantly associated with blood pressure in the general population. This finding is inconsistent with the results of recent occupational studies of lead exposed workers, although the occupational studies contained serious methodological weaknesses. The present study examined the relation between occupational lead exposure and diastolic and systolic blood pressure in randomly selected samples of 270 exposed and 158 non-exposed workers. Four exposure indicators were examined: employment at a lead battery plant nu a control plant, current blood lead value, current zinc protoporphyrin value, and time weighted average blood lead value. After controlling for other known risk factors such as age, education, income, cigarette usage, alcohol consumption, and exercise, the associations between exposure and blood pressure were small and non-significant. In the absence of a biologically feasible hypothesis regarding the mechanism by which low level lead exposure would influence blood pressure the present findings challenge the validity of the general population association. PMID:3689706

  16. Lead exposures from varnished floor refinishing.

    PubMed

    Schirmer, Joseph; Havlena, Jeff; Jacobs, David E; Dixon, Sherry; Ikens, Robert

    2012-01-01

    We evaluated the presence of lead in varnish and factors predicting lead exposure from floor refinishing and inexpensive dust suppression control methods. Lead in varnish, settled dust, and air were measured using XRF, laboratory analysis of scrape and wipe samples, and National Institute for Occupational Safety and Health (NIOSH) Method 7300, respectively, during refinishing (n = 35 homes). Data were analyzed using step-wise logistic regression. Compared with federal standards, no lead in varnish samples exceeded 1.0 mg/cm(2), but 52% exceeded 5000 ppm and 70% of settled dust samples after refinishing exceeded 40 μg/ft(2). Refinishing pre-1930 dwellings or stairs predicted high lead dust on floors. Laboratory analysis of lead in varnish was significantly correlated with airborne lead (r = 0.23, p = 0.014). Adding dust collection bags into drum sanders and HEPA vacuums to edgers and buffers reduced mean floor lead dust by 8293 μg Pb/ft(2) (p<0.05) on floors and reduced most airborne lead exposures to less than 50 μg/m(3). Refinishing varnished surfaces in older housing produces high but controllable lead exposures. PMID:22494405

  17. Lead exposure in outdoor firearm instructors

    SciTech Connect

    Tripathi, R.K.; Sherertz, P.C.; Llewellyn, G.C.; Armstrong, C.W. )

    1991-06-01

    This study was conducted to determine lead exposure of firearm instructors at an outdoor firing range, while cadets were firing nonjacketed and jacketed lead ammunitions. The breathing zone air for lead exceeded the Occupational Safety and Health Administration standard of 50 micrograms/m3 for two instructors during firing exercises using nonjacketed bullets. The use of totally copper-jacketed bullets reduced the breathing zone lead levels by 92 percent for instructor {number sign}1 and by 96 percent for instructor {number sign}2; subsequent blood lead levels showed a significant decline in both instructors.

  18. Sources of lead exposure in Mexico City.

    PubMed Central

    Romieu, I; Palazuelos, E; Hernandez Avila, M; Rios, C; Muñoz, I; Jimenez, C; Cahero, G

    1994-01-01

    Many countries, including Mexico, are facing a largely unrecognized epidemic of low-level lead poisoning. Mexico is the sixth largest lead-producing country in the world, and 40% of its production is used locally in different industrial processes that cause lead contamination of the environment. The major sources and pathways of lead exposure among the Mexican population are gasoline emissions, lead-glazed ceramics, leaded paint, and lead in canned foods and beverages. In this paper we present evidence for the presence of lead in different environmental media and its impact on blood lead levels of the Mexican population. Although during the last few years important measures have been implemented to decrease lead exposure, our findings suggest that lead poisoning is still an important problem in Mexico. There is an urgent need for regulatory policies that implement stricter control to protect the Mexican population. There is also a need to develop adequate programs to reduce the lead burden and the associated health effects in the population that has been chronically exposed. Images Figure 1. PMID:7523102

  19. Lead exposure among lead-acid battery workers in Jamaica.

    PubMed

    Matte, T D; Figueroa, J P; Burr, G; Flesch, J P; Keenlyside, R A; Baker, E L

    1989-01-01

    To assess lead exposure in the Jamaican lead-acid battery industry, we surveyed three battery manufacturers (including 46 production workers) and 10 battery repair shops (including 23 battery repair workers). Engineering controls and respiratory protection were judged to be inadequate at battery manufacturers and battery repair shops. At manufacturers, 38 of 42 air samples for lead exceeded a work-shift time-weighted average concentration of 0.050 mg/m3 (range 0.030-5.3 mg/m3), and nine samples exceeded 0.50 mg/m3. Only one of seven air samples at repair shops exceeded 0.050 mg/m3 (range 0.003-0.066 mg/m3). Repair shop workers, however, had higher blood lead levels than manufacturing workers (65% vs. 28% with blood lead levels above 60 micrograms/dl, respectively). Manufacturing workers had a higher prevalence of safe hygienic practices and a recent interval of minimal production had occurred at one of the battery manufacturers. Workers with blood lead levels above 60 micrograms/dl tended to have higher prevalences of most symptoms of lead toxicity than did workers with lower blood lead levels, but this finding was not consistent or statistically significant. The relationship between zinc protoporphyrin concentrations and increasing blood lead concentrations was consistent with that described among workers in developed countries. The high risk of lead toxicity among Jamaican battery workers is consistent with studies of battery workers in other developing countries. PMID:2773946

  20. Neural alterations from lead exposure in zebrafish.

    PubMed

    Roy, Nicole M; DeWolf, Sarah; Schutt, Alexius; Wright, Ashia; Steele, Latina

    2014-01-01

    Lead was used extensively as a gas additive and pesticide, in paints, batteries, lead shot, pipes, canning and toy manufacturing. Although uses of lead have been restricted, lead persists in our environment especially in older homes, and generally in soil and water. Although extensive studies have determined that fetal and childhood exposures to lead have been associated with childhood and adolescent memory impairments and learning disabilities, there are limited studies investigating early neural and morphological effects that may lead to these behavioral and learning abnormalities. Here we utilize the zebrafish vertebrate model system to study early effects of lead exposure on the brain. We treat embryos with 0.2mM lead for 24, 48 and 72 h and analyze neural structures through live imagery and transgenic approaches. We find structural abnormalities in the hindbrain region as well as changes in branchiomotor neuron development and altered neural vasculature. Additionally, we find areas of increased apoptosis. We conclude that lead is developmentally neurotoxic to a specific region of the brain, the hindbrain and is toxic to branchiomotor neurons residing in rhombomeres 2 through 7 of the hindbrain and hindbrain central artery vasculature. PMID:25242292

  1. AUDITORY AND VISUAL DYSFUNCTION FOLLOWING LEAD EXPOSURE

    EPA Science Inventory

    The effects of lead exposure on cognitive function have been intensively studied during the past decade, but relatively little effort has been made to understand the impact on sensory function. Subtle impairments of visual and/or auditory processing, however, could have profound ...

  2. Lead exposure from aluminum cookware in Cameroon.

    PubMed

    Weidenhamer, Jeffrey D; Kobunski, Peter A; Kuepouo, Gilbert; Corbin, Rebecca W; Gottesfeld, Perry

    2014-10-15

    Blood lead levels have decreased following the removal of lead from gasoline in most of the world. However, numerous recent studies provide evidence that elevated blood lead levels persist in many low and middle-income countries around the world at much higher prevalence than in the more developed countries. One potential source of lead exposure that has not been widely investigated is the leaching of lead from artisanal aluminum cookware, which is commonly used in the developing world. Twenty-nine samples of aluminum cookware and utensils manufactured by local artisans in Cameroon were collected and analyzed for their potential to release lead during cooking. Source materials for this cookware included scrap metal such as engine parts, radiators, cans, and construction materials. The lead content of this cookware is relatively low (<1000 ppm by X-ray fluorescence), however significant amounts of lead, as well as aluminum and cadmium were released from many of the samples using dilute acetic acid extractions at boiling and ambient temperatures. Potential exposures to lead per serving were estimated to be as high as 260 μg, indicating that such cookware can pose a serious health hazard. We conclude that lead, aluminum and cadmium can migrate from this aluminum cookware during cooking and enter food at levels exceeding recommended public health guidelines. Our results support the need to regulate lead content of materials used to manufacture these pots. Artisanal aluminum cookware may be a major contributor to lead poisoning throughout the developing world. Testing of aluminum cookware in other developing countries is warranted. PMID:25087065

  3. Exposure to lead affects male biothiols metabolism.

    PubMed

    Kasperczyk, Sławomir; Błaszczyk, Iwona; Dobrakowski, Michał; Romuk, Ewa; Kapka-Skrzypczak, Lucyna; Adamek, Mariusz; Birkner, Ewa

    2013-01-01

    The most important biothiols include glutathione, homocysteine (HCY), cysteine and proteins. The aim of the presented study was to evaluate the influence of lead on the biothiol turnover--the concentration of HCY and protein sulfhydryl groups (P-SH) in the serum and reduced glutathione (G-SH) in erythrocytes--in individuals (employees of metal works) exposed to lead and to evaluate its probable oxidative disorders, measured as the carbonyl protein (CP) concentration in serum. The exposed workers were divided into 2 subgroups: 1) low lead exposure (LPb), with a lead concentration in the blood (PbB) of 20-45 µg dl(-1) (n= 102), and 2) high lead exposure (HPb), with PbB = 45-60 µg dl(-1) (n= 81). The control group consisted of 72 office workers or other healthy subjects with no history of occupational exposure to lead. All the controls had normal PbB (<10 μg dl(-1)) and ZPP (<2.5 μg dl(-1)) levels. The concentration of HCY was higher in the LPb group by 11% and in the HPb group by 26%, compared with the control group (n=72). The CP concentration in these 2 groups was more than twice as high as that of the control group, with 108% and 125% increases for the LPb and HPb groups, respectively; G-SH was lower by 6.6% and 7.4% for the LPb and HPb groups, respectively; P-SH was lower by 8.2% and 13% for the LPb and HPb groups, respectively. Lead decreases levels of glutathione and protein thiol groups. Lead-induced oxidative stress contributes to the observed elevation of protein carbonyl groups. Besides, lead poisoning seems to be associated with hyperhomocysteinaemia, which may promote the development of atherosclerosis. PMID:24364442

  4. Lead exposure and radiator repair work

    SciTech Connect

    Lussenhop, D.H.; Parker, D.L.; Barklind, A.; McJilton, C. )

    1989-11-01

    In 1986, the ambient air for lead in radiator repair shops in the Minneapolis-St. Paul metropolitan area exceeded the Occupational Safety and Health Administration (OSHA) action level in nine of 12 shops sampled by Minnesota OSHA. We therefore sought to determine the prevalence of lead exposure/toxicity in this industry. Thirty-five radiator shops were identified, 30 were visited, and 53 workers were studied. The mean blood lead level was 1.53 (range 0.24-2.80). Seventeen individuals had blood lead levels greater than or equal to 1.93 mumol/L (40 micrograms/dl). The mean zinc protoporphyrin level (ZPP) was 0.55 mumol/L (range 0.16-1.43). No single worksite or personal characteristic was a strong determinant of either blood lead or ZPP level.

  5. Comparison of three models for predicting blood lead levels in children: episodic exposures to lead.

    PubMed

    Lakind, J S

    1998-01-01

    A threshold blood lead level in children below which no adverse effects occur has not been identified (CDC, 1991), Therefore, the traditional risk assessment method of relating dose to a reference dose (RfD) for noncancer effects is not applicable to lead. To assess whether environmental lead concentrations may result in adverse health effects, predicted blood lead levels are compared to a blood lead level of 10 micrograms/dL, the current Centers for Disease Control and Prevention level of concern. Children's blood lead levels may be predicted with one of at least three models: USEPA'S Integrated Exposure Uptake Biokinetic Model (IEUBK), and models by O'Flaherty (1993) and Carlisle and Wade (1992). This paper explores the utility of these models for predicting blood lead levels in children, and discusses areas of uncertainty associated with the use of these models in evaluating episodic exposures. It is hoped that this discussion will stimulate interest further researching exposure and health effects from episodic contact with lead contaminated media. PMID:9679219

  6. Exterior surface dust lead, interior house dust lead and childhood lead exposure in an urban environment

    SciTech Connect

    Bornschein, R.L.; Succop, P.A.; Krafft, K.M.; Clark, C.S.; Peace, B.; Hammond, P.B.

    1986-01-01

    The impact of urban lead exposure is being examined in a prospective study of several hundred children followed from birth to five years of age. A wide range of social, behavioral, biological and environmental factors are being assessed at approximately one year intervals beginning at birth. Previous analyses on this cohort have indicated a strong relationship between hand lead and hand-to-mouth activity and suggests that this is an important mechanism of inadvertent ingestion of lead in infants and young children. The present analyses was undertaken to examine the joint influence of lead in exterior surface dust and interior lead-containing painted surfaces on lead levels in house dust. In addition the joint influence of exterior and interior surface dust lead on children's hand lead content and blood lead concentration was examined. At 18 months of age 38% of the observed variation in blood lead was accounted for by hand lead and dust lead. Interior paint lead and exterior surface dust lead accounted for 52% of the observed variation in interior surface dust lead concentration. Exterior surface dust lead, obtained from exterior surface scrapings, indirectly influenced blood lead through its impact on interior house dust lead and children's hand lead content, but had no observable direct impact on blood lead. 13 references, 4 figures, 3 tables.

  7. Lead exposure in students in Mexico City.

    PubMed

    Alvear Galindo, M G; Carreón García, J; Moreno Altamirano, A; Cuéllar López, J A; Kimura, L Y

    1994-10-01

    The present study was done between 1989 and 1991 and performed on 263 children 7 to 9 years of age who lived in Mexico City. The goal was to determine the association between risk factors entering the body through the respiratory or digestive path and lead concentration in deciduous teeth. Exposure to risk factors was surveyed through a questionnaire; lead was determined by atomic absorption spectrophotometry with a graphite oven and reported in microgram Pb/g tooth. Statistical significance was found for the habit of sucking toys OR 4.98 (IC 95% 1.23-28.67), the use of glazed earthenware utensils for the preparation and serving of food and drinks OR 2.47 (IC 0.80-8.47), and the ingestion of tinned food, particularly juices OR 3.31 (IC 1.03-12.50). No positive results were found for risk factors involving the respiratory path. A possible explanation for these results is a different risk level for each of the two paths of access. PMID:7529159

  8. Spontaneous Lead Breakage in Implanted Spinal Cord Stimulation Systems

    PubMed Central

    Kim, Tae Hun; Son, Hye Min; Choi, Jong Bum; Moon, Jee Youn

    2010-01-01

    Spinal cord stimulation (SCS) has become an established clinical option for treatment of refractory chronic pain. Current hardware and implantation techniques for SCS are already highly developed and continuously improving; however, equipment failures over the course of long-term treatment are still encountered in a relatively high proportion of the cases treated with it. Percutaneous SCS leads seem to be particularly prone to dislocation and insulation failures. We describe our experience of lead breakage in the inserted spinal cord stimulator to a complex regional pain syndrome patient who obtained satisfactory pain relief after the revision of SCS. PMID:20552080

  9. SOURCES AND PATHWAYS OF LEAD EXPOSURE

    EPA Science Inventory

    Exposure is defined here as the amount of a substance that comes into contact with an absorbing surface during a specified period of time. The normal units of exposure are expressed as micrograms per day. The two components of exposure are the concentration of the substance in ...

  10. Lead exposure in US worksites: A literature review and development of an occupational lead exposure database from the published literature

    PubMed Central

    Koh, Dong-Hee; Locke, Sarah J.; Chen, Yu-Cheng; Purdue, Mark P.; Friesen, Melissa C.

    2016-01-01

    Background Retrospective exposure assessment of occupational lead exposure in population-based studies requires historical exposure information from many occupations and industries. Methods We reviewed published US exposure monitoring studies to identify lead exposure measurement data. We developed an occupational lead exposure database from the 175 identified papers containing 1,111 sets of lead concentration summary statistics (21% area air, 47% personal air, 32% blood). We also extracted ancillary exposure-related information, including job, industry, task/location, year collected, sampling strategy, control measures in place, and sampling and analytical methods. Results Measurements were published between 1940 and 2010 and represented 27 2-digit standardized industry classification codes. The majority of the measurements were related to lead-based paint work, joining or cutting metal using heat, primary and secondary metal manufacturing, and lead acid battery manufacturing. Conclusions This database can be used in future statistical analyses to characterize differences in lead exposure across time, jobs, and industries. PMID:25968240

  11. Biological tests of lead absorption following a brief massive exposure

    SciTech Connect

    Williams, M.K.

    1984-07-01

    A contractor's man suffered a brief, massive exposure to lead fume by contaminating and then smoking hand-rolled cigarettes. His blood lead concentration rose very rapidly to very high levels, but zinc erythrocyte protoporphyrin, urinary lead, and urinary coproporphyrin did not. It is possible that only the blood lead concentration is of value in detecting brief massive exposure.

  12. LEAD EXPOSURES IN THE HUMAN ENVIRONMENT

    EPA Science Inventory

    Humans consume lead by inhaling air, drinking beverages, eating food and ingesting dust. The natural source of this lead is primarily soil. Anthropogenic sources are lead in gasoline, fossil fuels and industrial products and processes. Lead is ubiquitous in the human environment,...

  13. Lead exposure in Canada geese of the Eastern Prairie Population

    USGS Publications Warehouse

    DeStefano, S.; Brand, C.J.; Rusch, D.H.; Finley, Daniel L.; Gillespie, M.M.

    1991-01-01

    We monitored lead exposure in Eastern Prairie Population Canada geese during summer-winter, 1986-1987 and 1987-1988 at 5 areas. Blood lead concentrations in geese trapped during summer at Cape Churchill Manitoba were below levels indicative of recent lead exposure (0.18 ppm). Geese exposed to lead (≥0.18 ppm blood lead) increased to 7.6% at Oak Hammock Wildlife Management Area (WMA), southern Manitoba, where lead shot was still in use, and to 10.0% at Roseau River WMA, northern Minnesota, when fall-staging geese were close to a source of lead shot in Manitoba. Proportion of birds exposed to lead dropped to <2% at Lac Qui Parle WMA, Minnesota, a steel shot zone since 1980. On the wintering grounds at Swan Lake National Wildlife Refuge in Missouri, 4.9% of all geese showed exposure to lead before the hunting season. Lead exposure rose to 10.0% after hunting ended and then decreased to 5.2% in late winter. Incidence of lead shot in gizzards and concentrations of lead in livers supported blood assay data. Soil samples indicated that lead shot continues to be available to geese at Swan Lake, even though the area was established as a non-toxic shot zone in 1978. Steel shot zones have reduced lead exposure in the Eastern Prairie Population, but lead shot persists in the environment and continues to account for lead exposure and mortality in Eastern Prairie Population Canada geese.

  14. Occupational and environmental human lead exposure in Brazil

    SciTech Connect

    Paoliello, M.M.B. . E-mail: monibas@sercomtel.com.br; De Capitani, E.M.

    2007-02-15

    The purpose of this paper is to present a review of data on assessment of exposure and adverse effects due to environmental and occupational lead exposure in Brazil. Epidemiological investigations on children lead exposure around industrial and mining areas have shown that lead contamination is an actual source of concern. Lead in gasoline has been phasing out since the 1980s, and it is now completely discontinued. The last lead mining and lead refining plant was closed in 1995, leaving residual environmental lead contamination which has recently been investigated using a multidisciplinary approach. Moreover, there are hundreds of small battery recycling plants and secondary smelting facilities all over the country, which produce focal urban areas of lead contamination. Current regulatory limits for workplace lead exposure have shown to be inadequate as safety limits according to a few studies carried out lately.

  15. Results of lead research: prenatal exposure and neurological consequences.

    PubMed Central

    Goyer, R A

    1996-01-01

    The history of advances in the understanding of the toxic effects of lead over the past 20 years is an outstanding example of how knowledge learned from research can impact public health. Measures that have had the greatest impact on reducing exposure to lead are reduction of lead from gasoline, elimination of lead solder from canned food, removal of lead from paint, and abatement of housing containing lead-based paint. Nevertheless, continuing factors that enhance risk to lead exposure, particularly during fetal life, are low socioeconomic status, old housing with lead-containing paint, and less than ideal nutrition, particularly low dietary intake of calcium, iron, and zinc. Prenatal exposure may result from endogenous sources such as lead in the maternal skeletal system or maternal exposures from diet and the environment. Experimental studies have shown that the developing nervous system is particularly sensitive to the toxic effects of lead and that a large number of the effects in the nervous system are due to interference of lead with biochemical functions dependent on calcium ions and impairment of neuronal connections dependent on dendritic pruning. There is need for more study to determine whether these effects are a continuum of prenatal lead exposure or whether prenatal exposure to lead produces unique effects. Images p1050-a Figure 1. A Figure 1. B Figure 2. Figure 3. PMID:8930545

  16. Soil is an important pathway of human lead exposure.

    PubMed Central

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are associated with severe lead poisoning. Leaded gasoline and lead in food, but not lead-based paint, are strongly associated with population blood lead levels in both young children and adults. Soil lead and house dust, but not lead-based paint, are associated with population blood lead levels in children. Most soil lead and house dust are associated with leaded gasoline. Lead-based paint dust is associated with cases of renovation of either exterior or interior environments in which the paint was pulverized. Based upon the limited data to date, abatement of soil lead is more effective than abatement of lead-based paint in reducing blood lead levels of young children. About equal numbers of children under 7 years of age are exposed to soil lead and lead-based paint. Seasonality studies point to soil lead as the main source of population blood lead levels. Soil lead is a greater risk factor than lead-based paint to children engaged in hand-to-mouth and pica behavior. In summary, soil lead is important for addressing the population of children at risk of lead poisoning. When soil lead is acknowledged by regulators and the public health community as an important pathway of human lead exposure, then more effective opportunities for improving primary lead prevention can become a reality. Images Figure 1 PMID:9539015

  17. Lead Exposure and Cardiovascular Disease—A Systematic Review

    PubMed Central

    Navas-Acien, Ana; Guallar, Eliseo; Silbergeld, Ellen K.; Rothenberg, Stephen J.

    2007-01-01

    Objective This systematic review evaluates the evidence on the association between lead exposure and cardiovascular end points in human populations. Methods We reviewed all observational studies from database searches and citations regarding lead and cardiovascular end points. Results A positive association of lead exposure with blood pressure has been identified in numerous studies in different settings, including prospective studies and in relatively homogeneous socioeconomic status groups. Several studies have identified a dose–response relationship. Although the magnitude of this association is modest, it may be underestimated by measurement error. The hypertensive effects of lead have been confirmed in experimental models. Beyond hypertension, studies in general populations have identified a positive association of lead exposure with clinical cardiovascular outcomes (cardiovascular, coronary heart disease, and stroke mortality; and peripheral arterial disease), but the number of studies is small. In some studies these associations were observed at blood lead levels < 5 μg/dL. Conclusions We conclude that the evidence is sufficient to infer a causal relationship of lead exposure with hypertension. We conclude that the evidence is suggestive but not sufficient to infer a causal relationship of lead exposure with clinical cardiovascular outcomes. There is also suggestive but insufficient evidence to infer a causal relationship of lead exposure with heart rate variability. Public Health Implications These findings have immediate public health implications. Current occupational safety standards for blood lead must be lowered and a criterion for screening elevated lead exposure needs to be established in adults. Risk assessment and economic analyses of lead exposure impact must include the cardiovascular effects of lead. Finally, regulatory and public health interventions must be developed and implemented to further prevent and reduce lead exposure. PMID:17431501

  18. Effectiveness of employee training and motivation programs in reducing exposure to inorganic lead and lead alkyls.

    PubMed

    Maples, T W; Jacoby, J A; Johnson, D E; Ter Haar, G L; Buckingham, F M

    1982-09-01

    The Occupational Safety and Health Administration has advanced engineering controls over administrative controls and protective equipment to reduce exposures to chemicals in the workplace. The application of employee training and motivation programs (such as job safety analysis) to reduce exposures to chemicals has not been emphasized. To determine the effectiveness of such programs, a pilot project in an alkyl lead production facility was conducted with 35 employees in an effort to reduce exposures to organic and inorganic lead. Results after 12 months show a 40% reduction in lead-in-urine and a 24% reduction in lead-in-blood, both indicators of total exposure to organic inorganic lead. PMID:7148690

  19. Lead exposures in the human environment. Final report

    SciTech Connect

    Elias, R.W.

    1985-01-01

    Humans consume lead by inhaling air, drinking beverages, eating food and ingesting dust. The natural source of this lead is primarily soil. Anthropogenic sources are lead in gasoline, fossil fuels and industrial products and processes. Lead is ubiquitous in the human environment, and pinpointing the primary sources of lead in any particular environmental component is difficult. Nevertheless, our purpose is to describe the total exposure of humans to environmental lead and to determine the sources of lead contributing to this exposure. The total exposure is the total amount of lead consumed by ingestion and inhalation. Excluding lead exposure from choice or circumstance, a baseline level of potential human exposure can be defined for a normal individual eating a typical diet and living in a non-urban community remote from industrial sources of lead in a house without lead-based paints. Beyond this level, additive exposure factors can be determined for other environments (e.g. urban, occupational and smelter communities) and for certain habits and activities (e.g. pica, smoking, drinking and hobbies), with variation for age, sex or socioeconomic status.

  20. Prenatal lead exposure and bone growth. Doctoral thesis

    SciTech Connect

    Hamilton, J.D.; O'Flaherty, E.J.

    1990-07-24

    An experimental system of lead (7439921) related prenatal and postnatal growth retardation in rats was developed. Sprague-Dawley-rats and Long-Evans-rats were used in these studies. Rats were exposed to lead in their drinking water at up to 1000 parts per million. A significant effect on fetal bone mineralization could not be excluded and there was a definite effect on fetal body weight following maternal lead exposure. Reduced food intake during the first week of lead exposure was the primary determinant of reduced body and skeletal growth in the lead exposed weanling female rats. When maternal lead exposure was continued during lactation a greater degree of lead related growth retardation in rat offspring occurred than when maternal lead exposure was terminated at parturition. Combined prenatal and postnatal lead exposure impaired bone resorption and increased growth plate widths. In studies using matrix induced endochondral bone plaques, locally applied lead enhanced plaque mineralization through comineralization of lead with calcium. When lead was administered in drinking water, plaque mineralization was also enhanced through the comineralization of lead with calcium.

  1. Renal effects of environmental and occupational lead exposure.

    PubMed Central

    Loghman-Adham, M

    1997-01-01

    Environmental and industrial lead exposures continue to pose major public health problems in children and in adults. Acute exposure to high concentrations of lead can result in proximal tubular damage with characteristic histologic features and manifested by glycosuria and aminoaciduria. Chronic occupational exposure to lead, or consumption of illicit alcohol adulterated with lead, has also been linked to a high incidence of renal dysfunction, which is characterized by glomerular and tubulointerstitial changes resulting in chronic renal failure, hypertension, hyperuricemia, and gout. A high incidence of nephropathy was reported during the early part of this century from Queensland, Australia, in persons with a history of childhood lead poisoning. No such sequela has been found in studies of three cohorts of lead-poisoned children from the United States. Studies in individuals with low-level lead exposure have shown a correlation between blood lead levels and serum creatinine or creatinine clearance. Chronic low-level exposure to lead is also associated with increased urinary excretion of low molecular weight proteins and lysosomal enzymes. The relationship between renal dysfunction detected by these sensitive tests and the future development of chronic renal disease remains uncertain. Epidemiologic studies have shown an association between blood lead levels and blood pressure, and hypertension is a cardinal feature of lead nephropathy. Evidence for increased body lead burden is a prerequisite for the diagnosis of lead nephropathy. Blood lead levels are a poor indicator of body lead burden and reflect recent exposure. The EDTA lead mobilization test has been used extensively in the past to assess body lead burden. It is now replaced by the less invasive in vivo X-ray fluorescence for determination of bone lead content. Images p928-a Figure 1. Figure 2. Figure 2. Figure 3. PMID:9300927

  2. Lead exposure from battery recycling in Indonesia.

    PubMed

    Haryanto, Budi

    2016-03-01

    In Indonesia, more than 200 illegal used lead acid battery (ULAB) smelters are currently operating. Only a few health studies support the finding of lead-related symptoms and diseases among populations living near the smelters. To assess the blood lead levels (BLLs) and potential health impacts among the population surrounding ULAB recycling smelters, we evaluated health effects reported from 2003 to 2013, conducted focus group discussions with lead smelter owner/workers and a group of 35 female partners of smelter owners or workers not actively engaged in smelter work, and retook and measured BLLs. It was found that many children in the areas were having difficulty achieving high grades at school and having stunting or other problems with physical development. The average mean of BLLs increased by almost double in 2015, compared with in 2011. The risk of having hypertension, interference in the ability to make red blood cells in females occurred among 24% of respondents; Elevated blood pressure, hearing loss, and interference in the ability to make red bloods cell occurred in 20% of males; Kidney damage, infertility in male, nerve problems, including decreased sensation and decreased ability to move quickly occurred in 13%; Decreased ability to make red blood cells (20%), and; Frank anemia, decreased life-span, coma/seizures were experienced by 22%. The populations living in areas surrounding ULAB smelters are experiencing severe chronic health problems. It is recommended that the smelters must be moved and placed far away from the municipality. PMID:26812760

  3. Effect of Prenatal Exposure to Lead on Estrogen Action in the Prepubertal Rat Uterus

    PubMed Central

    Tchernitchin, Andrei N.; Gaete, Leonardo; Bustamante, Rodrigo; Báez, Aracelly

    2011-01-01

    Lead is a widely spread environmental pollutant known to affect both male and female reproductive systems in humans and experimental animals and causes infertility and other adverse effects. The present paper investigated the effects of prenatal exposure to lead on different parameters of estrogen stimulation in the uterus of the prepubertal rat. In prenatally and perinatally exposed rats, estrogen-induced endometrial eosinophilia, endometrial stroma edema, and eosinophil migration towards the endometrium, and uterine luminal epithelial hypertrophy are enhanced while several other responses to estrogen appear unchanged. These effects may contribute to decrease in fertility following prenatal exposure to lead. The striking difference between most of these effects of prenatal exposure and the previously reported effects of chronic exposure to lead suggests that prenatal exposure to lead may neutralize the effects of chronic exposure to lead, providing partial protection of cell function against the adverse effects of chronic exposure to lead. We propose that the mechanism involved, named imprinting or cell programming, persisted through evolution as a nongenetic adaptive mechanism to provide protection against long-term environmental variations that otherwise may cause the extinction of species not displaying this kind of adaptation. PMID:22263113

  4. Effect of prenatal exposure to lead on estrogen action in the prepubertal rat uterus.

    PubMed

    Tchernitchin, Andrei N; Gaete, Leonardo; Bustamante, Rodrigo; Báez, Aracelly

    2011-01-01

    Lead is a widely spread environmental pollutant known to affect both male and female reproductive systems in humans and experimental animals and causes infertility and other adverse effects. The present paper investigated the effects of prenatal exposure to lead on different parameters of estrogen stimulation in the uterus of the prepubertal rat. In prenatally and perinatally exposed rats, estrogen-induced endometrial eosinophilia, endometrial stroma edema, and eosinophil migration towards the endometrium, and uterine luminal epithelial hypertrophy are enhanced while several other responses to estrogen appear unchanged. These effects may contribute to decrease in fertility following prenatal exposure to lead. The striking difference between most of these effects of prenatal exposure and the previously reported effects of chronic exposure to lead suggests that prenatal exposure to lead may neutralize the effects of chronic exposure to lead, providing partial protection of cell function against the adverse effects of chronic exposure to lead. We propose that the mechanism involved, named imprinting or cell programming, persisted through evolution as a nongenetic adaptive mechanism to provide protection against long-term environmental variations that otherwise may cause the extinction of species not displaying this kind of adaptation. PMID:22263113

  5. Dietary exposure to lead of adults in Shenzhen city, China.

    PubMed

    Pan, Liubo; Wang, Zhou; Peng, Zhaoqiong; Liu, Guihua; Zhang, Huimin; Zhang, Jinzhou; Jiang, Jie; Pathiraja, Nimal; Xiao, Ying; Jiao, Rui; Huang, Wei

    2016-07-01

    Lead, a ubiquitous heavy metal, can be found in the environment and food. The present study is the first to estimate the lead dietary exposure of Shenzhen adults (≥ 20 years old) in various age-gender subgroups, and to assess the associated health risk. Food samples that represented the Shenzhen people's dietary pattern were collected and prepared for analysis. Lead was determined in 13 food groups using 276 individual cooked samples by inductively coupled plasma-mass spectrometry (ICP-MS). Dietary exposures were estimated by combining the analytical results with the local food consumption data of Shenzhen adults. The mean and 95th percentile lead exposure of Shenzhen adults were 0.59-0.73 and 0.75-0.94 μg kg(-1) bw day(-1), respectively. In all food groups, the highest lead exposure was from 'Eggs and their products' (42.4-51.6% of the total exposure); preserved eggs being the main contributor. The other major contributors to lead exposure of Shenzhen adults were 'Fish and seafood, and their products' (14.3-16.7% of the total exposure) and 'Vegetables and their products' (15.5-16.2% of the total exposure). The margin of exposure (MOE) approach was used for the risk assessment of lead, and the results showed that the risk was considered to be low in all age-gender groups for Shenzhen adults. However, having considered a number of toxic effects of lead, it is suggested that more efforts should be made to reduce the lead levels in foodstuff for Shenzhen adults. PMID:27295315

  6. Prenatal and early postnatal lead exposure in mice: neuroimaging findings

    PubMed Central

    Lindquist, Diana M.; Beckwith, Travis; Sánchez-Martín, Francisco Javier; Landero-Figueroa, Julio; Puga, Alvaro

    2015-01-01

    Background Childhood lead exposure has been linked to adult gray matter loss accompanied by changes in myelination and neurochemistry noninvasively revealed by magnetic resonance imaging (MRI) methods. However, the extent, duration and timing of lead exposure required to produce such imaging changes in humans are difficult to ascertain. Methods To determine if such changes are related to early exposure to low levels of lead, we treated mouse dams with 0, 3, or 30 ppm of lead acetate in drinking water for 2 months prior to mating through gestation until weaning of the offspring at post-natal day 21. Two male and two female pups from each litter were imaged at post-natal day 60. Volumetric, diffusion tensor imaging and magnetic resonance spectroscopy (MRS) measurements were obtained using a seven Tesla Bruker animal MRI scanner. Results Postnatal blood lead levels were identical between groups at the time of imaging. No effects of lead exposure were detected in the volumetric or MRS data. Mean diffusivity in the hippocampus showed significant effects of lead exposure and gender. Conclusions These data suggest that low-level, gestational lead exposure in a mouse model produces minimal changes observed by MRI. PMID:26435914

  7. DIETARY EXPOSURE OF CHILDREN LIVING IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors: they have more opportunity for contact with lead sources due to their activities; lead absorption occurs more readily in a child as compared to an adult; and the child's developmen...

  8. DIETARY EXPOSURE OF CHILDREN IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors; they have more opportunity for contact with lead sources due to their activities, lead absorption occurs more readily in a child compared to an adult, and the child's development i...

  9. Effect of exposure to lead on reproduction in male rats

    SciTech Connect

    Piasek, M.; Kostial, K.

    1987-09-01

    The objective of present study was to determine the effect of chronic oral exposure to different levels of lead on male reproductive performance since oral exposure data are more relevant to human environmental exposure. Additionally, most previous results have been obtained after parenteral administration of lead. These experiments were performed on rats by using the incidence of pregnancy to assess male fertility and litter size and pup weight as indicators of the lead effect on perinatal development. Similar parameters were used in reproduction studies by other authors.

  10. Biological monitoring of child lead exposure in the Czech Republic.

    PubMed

    Cikrt, M; Smerhovsky, Z; Blaha, K; Nerudova, J; Sediva, V; Fornuskova, H; Knotkova, J; Roth, Z; Kodl, M; Fitzgerald, E

    1997-04-01

    The area around the Pribram lead smelter has been recognized to be heavily contaminated by lead (Pb). In the early 1970s, several episodes of livestock lead intoxication were reported in this area; thereafter, several epidemiological and ecological studies focused on exposure of children. In contrast to earlier studies, the recent investigation (1992-1994) revealed significantly lower exposure to lead. From 1986-1990, recorded average blood lead levels were about 37.2 micrograms lead (Pb)/100 ml in an elementary school population living in a neighborhood close to the smelter (within 3 km of the plant). The present study, however, has found mean blood lead levels of 11.35 micrograms/100 ml (95% CI = 9.32; 13.82) among a comparable group of children. In addition to blood lead, tooth lead was used to assess exposure among children. Statistically significant differences (p < 0.05) were observed between the geometric mean tooth lead level of 6.44 micrograms Pb/g (n = 13; 95% CI = 3.95; 10.50) in the most contaminated zone and 1.43 micrograms Pb/g (n = 35; 95% CI = 1.11; 1.84) in zones farther away from the point source. Both biomarkers, blood and tooth lead levels, reflect a similar pattern of lead exposure in children. This study has attempted a quantitative assessment of risk factors associated with elevated lead exposure in the Czech Republic. Content of lead in soil, residential distance from the smelter, consumption of locally grown vegetables or fruits, drinking water from local wells, the mother's educational level, cigarette consumption among family members, and the number of children in the family were factors positively related (p < 0.05) to blood lead levels. The resulting blood lead level was found to be inversely proportional to the child's age. PMID:9189705

  11. Biological monitoring of child lead exposure in the Czech Republic.

    PubMed Central

    Cikrt, M; Smerhovsky, Z; Blaha, K; Nerudova, J; Sediva, V; Fornuskova, H; Knotkova, J; Roth, Z; Kodl, M; Fitzgerald, E

    1997-01-01

    The area around the Pribram lead smelter has been recognized to be heavily contaminated by lead (Pb). In the early 1970s, several episodes of livestock lead intoxication were reported in this area; thereafter, several epidemiological and ecological studies focused on exposure of children. In contrast to earlier studies, the recent investigation (1992-1994) revealed significantly lower exposure to lead. From 1986-1990, recorded average blood lead levels were about 37.2 micrograms lead (Pb)/100 ml in an elementary school population living in a neighborhood close to the smelter (within 3 km of the plant). The present study, however, has found mean blood lead levels of 11.35 micrograms/100 ml (95% CI = 9.32; 13.82) among a comparable group of children. In addition to blood lead, tooth lead was used to assess exposure among children. Statistically significant differences (p < 0.05) were observed between the geometric mean tooth lead level of 6.44 micrograms Pb/g (n = 13; 95% CI = 3.95; 10.50) in the most contaminated zone and 1.43 micrograms Pb/g (n = 35; 95% CI = 1.11; 1.84) in zones farther away from the point source. Both biomarkers, blood and tooth lead levels, reflect a similar pattern of lead exposure in children. This study has attempted a quantitative assessment of risk factors associated with elevated lead exposure in the Czech Republic. Content of lead in soil, residential distance from the smelter, consumption of locally grown vegetables or fruits, drinking water from local wells, the mother's educational level, cigarette consumption among family members, and the number of children in the family were factors positively related (p < 0.05) to blood lead levels. The resulting blood lead level was found to be inversely proportional to the child's age. Images Figure 1. PMID:9189705

  12. Childhood Lead Exposure from Battery Recycling in Vietnam

    PubMed Central

    Daniell, William E.; Van Tung, Lo; Wallace, Ryan M.; Havens, Deborah J.; Karr, Catherine J.; Bich Diep, Nguyen; Croteau, Gerry A.; Beaudet, Nancy J.; Duy Bao, Nguyen

    2015-01-01

    Background. Battery recycling facilities in developing countries can cause community lead exposure. Objective. To evaluate child lead exposure in a Vietnam battery recycling craft village after efforts to shift home-based recycling outside the village. Methods. This cross-sectional study evaluated 109 children in Dong Mai village, using blood lead level (BLL) measurement, parent interview, and household observation. Blood samples were analyzed with a LeadCare II field instrument; highest BLLs (≥45 μg/dL) were retested by laboratory analysis. Surface and soil lead were measured at 11 households and a school with X-ray fluorescence analyzer. Results. All children had high BLLs; 28% had BLL ≥45 μg/dL. Younger age, family recycling, and outside brick surfaces were associated with higher BLL. Surface and soil lead levels were high at all tested homes, even with no recycling history. Laboratory BLLs were lower than LeadCare BLLs, in 24 retested children. Discussion. In spite of improvements, lead exposure was still substantial and probably associated with continued home-based recycling, legacy contamination, and workplace take-home exposure pathways. There is a need for effective strategies to manage lead exposure from battery recycling in craft villages. These reported BLL values should be interpreted cautiously, although the observed field-laboratory discordance may reflect bias in laboratory results. PMID:26587532

  13. Occupational exposure to airborne lead in Brazilian police officers.

    PubMed

    Rocha, Ernesto Díaz; Sarkis, Jorge E Souza; Carvalho, Maria de Fátima H; Santos, Gerson Vechio Dos; Canesso, Claudemir

    2014-07-01

    Shooting with lead-containing ammunition in indoor firing ranges is a known source of lead exposure in adults. Police officers may be at risk of lead intoxication when regular training shooting exercises are yearly mandatory to law enforcement officers. Effects on health must be documented, even when low-level elemental (inorganic) lead exposure is detected. Forty police officers (nineteen cadets and twenty-one instructors) responded to a questionnaire about health, shooting habits, and potential lead exposure before a training curse. Blood samples were collected and analyzed for blood lead level (BLL) before and after a three days training curse. The mean BLL for the instructors' group was 5.5 μg/dL ± 0.6. The mean BLL for the cadets' group before the training was 3.3 μg/dL ± 0.15 and after the training the main BLL was 18.2 μg/d L± 1.5. Samples were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). All the participants in the training curse had significantly increased BLL (mean increment about 15 μg/dL) after the three days indoor shooting season. In conclusion, occupational lead exposure in indoor firing ranges is a source of lead exposure in Brazilian police officers, and appears to be a health risk, especially when heavy weapons with lead-containing ammunition are used in indoor environments during the firing training seasons. PMID:24411572

  14. Assessment of lead exposure in waterfowl species, Korea.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2014-11-01

    Lead concentrations were analyzed in white-fronted geese (Anser albifrons, n = 15), mallards (Anas platyrhynchos, n = 4), and spot-billed ducks (A. poecilorhyncha, n = 13) found dead near Gimpo, Korea, to determine tissue- and species-specific lead concentration differences and to assess the effect of embedded lead shot. In livers, kidneys, and bones (tarsus), mallards and spot-billed ducks with embedded shot had greater lead concentrations than white-fronted geese and spot-billed ducks without lead shot. Lead concentrations in spot-billed ducks were greater in bones than in livers and kidneys suggesting chronic exposure to lead. Lead concentrations in 8 of 32 livers, 5 of 32 kidneys, and 9 of 32 bones exceeded the threshold level of abnormal exposure for wild birds (>5 µg/g dw in lives, >6 µg/g dw in kidney, and >6.75 µg/g dw in bone). Increased lead concentrations in soft tissues and bones might be attributed to increased lead shot ingestion and embedded shot. Lead concentrations were correlated between livers and kidneys, between livers and bones, and between kidneys and bones. These results suggest that a relationship between acute exposure in livers and kidneys and chronic exposure in bones. PMID:24854704

  15. The Yugoslavia Prospective Study of environmental lead exposure.

    PubMed Central

    Factor-Litvak, P; Wasserman, G; Kline, J K; Graziano, J

    1999-01-01

    The Yugoslavia Prospective Study of environmental lead exposure has studied the associations between exposure to lead and pregnancy outcomes; childhood neuropsychological, behavioral, and physical development; and hematologic, renal, and cardiovascular function. The cohort comprises 577 children born to women recruited at midpregnancy in two towns in Kosovo, Yugoslavia; one town is the site of a lead smelter, refinery, and battery plant and the other is 25 miles away and relatively unexposed. A sample of these children has been followed at 6-month intervals through 7.5 years of age. Blood lead concentrations ranged from 1 to 70 microg/dl. Exposure to lead was not associated with adverse pregnancy outcomes. Exposure was associated with modest decrements in intelligence, small increases in blood pressure, higher risks of proteinuria, small increases in behavior problems, and perturbed hematopoiesis. Only at low level exposures (i.e., <16 microg/dl) were small associations with decreased height found. We discuss methodological problems that may hinder causal interpretation of these data, namely, use of blood lead concentration as an exposure measure, confounding, and town-specific associations. We conclude that while reported associations are small, collectively they lend support to the notion that lead is a toxicant with numerous adverse health effects. Images Figure 1 PMID:9872712

  16. Home lead-work as a potential source of lead exposure for children.

    PubMed

    Kawai, M; Toriumi, H; Katagiri, Y; Maruyama, Y

    1983-01-01

    Health examinations for lead poisoning were made on 62 family members from 15 families of homes carrying on lead work, such as quench-hardening in a molten lead bath and type-printing, as work at home. The most interesting findings concern the occurrence of cases with an unduly high lead absorption among children, but not among adult family members other than home lead-workers. The home environments of the children with an unduly high lead absorption represented contamination with housedust high in lead contents. The ingestion of the contaminated housedust by hand-to-mouth is probably responsible for the excessive lead exposure of the affected children. The results of the present study suggest that contamination of housedust with lead due to home lead-work constitutes a possible hazardous source of lead exposure for children. PMID:6654500

  17. Control of excessive lead exposure in radiator repair workers

    SciTech Connect

    Not Available

    1991-03-01

    In 1988, 83 automotive repair workers with blood lead levels (BLLs) greater than 25 micrograms/dL were reported to state health departments in the seven states that collaborated with CDC's National Institute for Occupational Safety and Health (NIOSH) in maintaining registries of elevated BLLs in adults. In 18 (22%) of these 83 persons, BLLs were greater than 50 micrograms/dL. Among automotive repair workers for whom a job category was specified, radiator repair work was the principal source of lead exposure. The major sources of exposure for radiator repair workers are lead fumes generated during soldering and lead dust produced during radiator cleaning. This report summarizes current BLL surveillance data for radiator repair workers and describes three control technologies that are effective in reducing lead exposures in radiator repair shops.

  18. Study and models of total lead exposures of battery workers.

    PubMed

    Chavalitnitikul, C; Levin, L; Chen, L C

    1984-12-01

    In an attempt to establish a more realistic and reliable model for relating environmental exposure measurements to the biological indices of exposure, a study was undertaken to quantify the total sources of lead exposure among lead storage battery workers. In addition to the usual personal and area lead air sampling, quantitative and repeatable measurements of removable lead from work surfaces and the workers' hands and faces were obtained daily for ten consecutive work days in the pasting and battery assembly departments. Mathematical correlations of blood lead and zinc protoporphyrin (ZPP) levels as the dependent variable with the lead exposure sources were derived and demonstrated most strongly as log-log relationships. Statistical analyses by computer programming indicated that the airborne, hand, facial and work surface levels have a high degree of inter-correlation with a very significant positive individual correlation with blood lead levels and a somewhat lower correlation with ZPP. The results suggest that contaminated personal and work surfaces may play a more significant role in toxic occupational and environmental exposures, generally, than had heretofore been demonstrated or suspected. PMID:6517025

  19. Site-specific lead exposure from lead pellet ingestion in sentinel mallards

    USGS Publications Warehouse

    Rocke, T.E.; Brand, C.J.; Mensik, John G.

    1997-01-01

    We monitored lead poisoning from the ingestion of spent lead pellets in sentinel mallards (Anas platyhrynchos) at the Sacramento National Wildlife Refuge (SNWR), Willows, California for 4 years (1986-89) after the conversion to steel shot for waterfowl hunting on refuges in 1986. Sentinel mallards were held in 1.6-ha enclosures in 1 hunted (P8) and 2 non-hunted (T19 and TF) wetlands. We compared site-specific rates of lead exposure, as determined by periodic measurement of blood lead concentrations, and lead poisoning mortality between wetlands with different lead pellet densities, between seasons, and between male and female sentinels. In 1986, the estimated 2-week rate of lead exposure was significantly higher (P < 0.005) in P8 (43.8%), the wetland with the highest density of spent lead pellets (>2,000,000 pellets/ha), than in those with lower densities of lead pellets, T19 (18.1%; 173,200 pellets/ha) and TF (0.9%; 15,750 pellets/ha). The probability of mortality from lead poisoning was also significantly higher (P < 0.01) in sentinel mallards enclosed in P8 (0.25) than T19 (0) and TF (0) in 1986 and remained significantly higher (P < 0.001) during the 4-year study. Both lead exposure and the probability of lead poisoning mortality in P8 were significantly higher (P < 0.001) in the fall of 1986 (43.8%; 0.25), before hunting season, than in the spring of 1987 (21.6%; 0.04), after hunting season. We found no significant differences in the rates of lead exposure or lead poisoning mortality between male and female sentinel mallards. The results of this study demonstrate that in some locations, lead exposure and lead poisoning in waterfowl will continue to occur despite the conversion to steel shot for waterfowl hunting.

  20. Lead exposure in Nunavik: from research to action

    PubMed Central

    Couture, Ariane; Levesque, Benoît; Dewailly, Éric; Muckle, Gina; Déry, Serge; Proulx, Jean-François

    2012-01-01

    Background In 1999, the Government of Canada regulated the use of lead shot for hunting. Concurrently, the Nunavik Regional Board of Health and Social Services (NRBHSS) was informed of the results of an isotope study that pointed to lead ammunition as a likely source of lead exposure in Nunavik. Rapidly thereafter, a coalition for the banning of lead shot was implemented by the NRBHSS as well as by regional/local partners and by Inuit hunters in order to disseminate this information to the public. Objectives The purpose of this article is to describe the intervention conducted in the winter of 1999 by the NRBHSS and to assess the combined impact of national legislation and an awareness campaign on blood lead levels in Nunavik. Study design Impact assessment of the intervention for the banning of lead shot conducted in 1999 in Nunavik using blood lead levels data before and after the intervention. Methods Data on blood lead levels in Nunavik describing foetal exposure as well as during childhood and in adults published between 1992 and 2009 were compiled. Blood lead levels in Nunavik prior to and after the interventions were compared. To assess the current situation, the most recent blood lead levels were compared with those from surveys conducted during the same period in North America. Results Analysis of blood samples collected from umbilical cord and from adults show that blood lead levels in Nunavik significantly declined between 1992 and 2004. Nevertheless, lead exposure in Nunavik still remains higher in comparison to that observed in other North American surveys. Conclusions The current situation regarding lead exposure in Nunavik has significantly improved as a result of the implemented intervention. However, according to recent data, a gap still subsists relative to other North American populations. PMID:22818717

  1. Environmental lead exposure: a public health problem of global dimensions.

    PubMed Central

    Tong, S.; von Schirnding, Y. E.; Prapamontol, T.

    2000-01-01

    Lead is the most abundant of the heavy metals in the Earth's crust. It has been used since prehistoric times, and has become widely distributed and mobilized in the environment. Exposure to and uptake of this non-essential element have consequently increased. Both occupational and environmental exposures to lead remain a serious problem in many developing and industrializing countries, as well as in some developed countries. In most developed countries, however, introduction of lead into the human environment has decreased in recent years, largely due to public health campaigns and a decline in its commercial usage, particularly in petrol. Acute lead poisoning has become rare in such countries, but chronic exposure to low levels of the metal is still a public health issue, especially among some minorities and socioeconomically disadvantaged groups. In developing countries, awareness of the public health impact of exposure to lead is growing but relatively few of these countries have introduced policies and regulations for significantly combating the problem. This article reviews the nature and importance of environmental exposure to lead in developing and developed countries, outlining past actions, and indicating requirements for future policy responses and interventions. PMID:11019456

  2. Parental occupational lead exposure and lead concentration of newborn cord blood

    SciTech Connect

    Wang, J.D.; Shy, W.Y.; Chen, J.S.; Yang, K.H.; Hwang, Y.H.

    1989-01-01

    The purpose of this study was to determine the influence of parental occupational lead exposure on the lead levels of newborn cord blood in the Taipei area. From September 1984 to June 1985, 5,000 pregnant women voluntarily participated in the study at the Taipei Municipal Maternal and Child Hospital. Each woman was interviewed regarding her and her husband's occupational exposures; 2,948 successfully delivered healthy newborns, and cord blood samples were obtained using Terumo Venoject, and 242 samples were analyzed by graphite furnace atomic absorption spectrometry using an Instrumentation Laboratory 251 instrument. Nine cord blood samples were from newborns with both parents exposed, 26 samples had maternal exposure only, 105 samples had paternal exposure only, and 102 were nonexposed. The results showed that the average lead level of cord blood with both parents exposed was 8.9 +/- 2.9 micrograms%, maternal exposure 9.0 +/- 3.8 micrograms%, paternal exposure 8.3 +/- 3.4 micrograms%, and 6.9 +/- 3.2 micrograms% in the nonexposed group. There were significant differences between the nonexposed and the maternal exposure groups, and also between the nonexposed and paternal exposure groups. All 26 maternal exposures were from lead soldering operations. Multivariate analysis revealed that, after control of father's exposure status, newborn cord blood lead level increased 0.27 micrograms% for each hour the mother spent on lead soldering during a normal working day, thus suggesting that soldering during pregnancy may be hazardous to newborns. Paternal contribution to the cord blood lead levels seemed to be through either working at home with the pregnant mother also at home or bringing work clothes home for laundering.

  3. Biochemical diagnosis of occupational exposure to lead toxicity

    SciTech Connect

    Somashekaraiah, B.V.; Venkaiah, B.; Prasad, A.R.K. )

    1990-02-01

    Lead has been shown to interfere with the biosynthesis of heme in a number of in vitro systems and in experimental animals as well as in human beings. Several steps of the heme biosynthetic chain are subject to the toxic effects of lead. ALA- dehydratase and Ferrochelatase, in particular, are two enzymes which are strongly inhibited by lead, leading to decreased heme synthesis, a constituent of hemoglobin. The inhibition of ALA dehydratase in the red blood cells by lead is generally recognized as the most sensitive index of the individuals exposure to this environmental chemical. Earlier reports show that the determination of blood lead content (Pb-B), zinc protoporphyrin levels and erythrocyte Aminolevulinic acid dehydratase (ALA.D) are widely used as biological indicators for lead toxicity. Hence, the aim of the present study was to screen for occupational exposure to lead in the workers of three different occupations and correlate their blood lead levels with erythrocyte ALA.D and total blood porphyrin content as biochemical indicators of lead exposure.

  4. Environmental lead exposure and children’s cognitive function

    PubMed Central

    CANFIELD, R. L.; JUSKO, T. A.; KORDAS, K.

    2015-01-01

    Summary Recent research has substantially increased knowledge about the effects of low-level lead exposure on children’s neurobehavioral development. This update article focuses on two specific areas of recent research: low-level effects on cognitive function, and results from experimental and observational studies designed to prevent or reverse the damaging effects of lead on intellectual development, either through chelation therapy or micronutrient supplementation. Taken as a whole, these studies suggest that there is no safe level of lead exposure for young children and, although small, these effects are enduring and possibly permanent. PMID:26660292

  5. Environmental lead exposure to toll booth workers in Hong Kong

    SciTech Connect

    Tan, T.C.; Wong, L.T.L.; Lam, C.W.K.

    1988-01-01

    A survey of workers in the Lion Rock Tunnel toll booths was conducted, as they were regarded as a high risk group in lead exposure due to high density of vehicular traffic. The exposure of the workers to lead was determined by continuous sapling of air around the breathing zone of workers inside the booths. Blood lead concentration of 50 workers showed a mean of 0.65 {mu}mol/L and the mean urine lead concentration was 0.14 {mu}mol/L. Other tests, such as urinary amino-levulinic acid (ALA), erythrocyte zinc protoporphyrin (ZnPP) and hemoglobin concentration (Hb), were also preformed. The blood lead concentrations and other biological parameters of the toll-booth workers were acceptable and may be attributed to the recent legislation to lower the lead content in petrol and to the good preventive measures taken by the management.

  6. The association between caries and childhood lead exposure.

    PubMed Central

    Campbell, J R; Moss, M E; Raubertas, R F

    2000-01-01

    Epidemiologic studies suggest an association between lead exposure and caries. Our objective was to establish whether children with a higher lead exposure as toddlers had more caries at school age than children with a lower lead exposure. We used a retrospective cohort design. A sample of children who attended second and fifth grades in the Rochester, New York, public schools during the 1995-1996 and 1996-1997 school years were examined for caries through a dental screening program. For each child we assessed the number of decayed, missing, or filled surfaces on permanent teeth (DMFS), and the number of decayed or filled surfaces on deciduous teeth (dfs); the number of surfaces at risk (SAR) was also recorded. Lead exposure was defined as the mean of all blood lead levels collected between 18 and 37 months of age by fingerstick [provided the blood lead level was [less than/equal to] 10 microg/dL)] or venipuncture. A total of 248 children (197 second graders and 51 fifth graders) were examined for caries and had a record of blood lead levels to define lead exposure. The mean dfs was 3.4 (range 0-29); the mean DMFS was 0.5 (range 0-8). Logistic regression was used to examine the association between the proportion of children with DMFS [Greater/equal to] 1, and the proportion with dfs [Greater/equal to] 1, and lead exposure [< 0.48 micromol/L vs. [Greater/equal to] 0.48 micromol/L (< 10 microg/dL vs. [Greater/equal to] 10 microg/dL)] while controlling for SAR, age at examination, and grade in school. For DMFS, the adjusted odds ratio was 0.95 [95% confidence interval (CI), 0.43-2.09; p = 0.89); for dfs, the odds ratio was 1.77 (95% CI, 0.97-3.24; p = 0.07). This study did not demonstrate that lead exposure > 10 microg/dL as a toddler was a strong predictor of caries among school-age children. However, the results should be interpreted cautiously because of limitations in the assessment of lead exposure and limited statistical power. PMID:11102303

  7. Exposure of migrant bald eagles to lead in prairie Canada.

    PubMed

    Miller, M J; Wayland, M E; Bortolotti, G R

    2001-01-01

    The prevalence of elevated exposure to lead was assessed in a migrant population of bald eagles (Haliaeetus leucocephalus) at a waterfowl staging area in the southern portion of the Canadian prairies, from September to November, 1992-1995. Of 103 eagles, 8% exhibited blood lead (PbB) concentrations suggestive of elevated exposure to lead (> or = 0.200 microgram ml-1 wet wt.). PbB concentrations in eagles from the study area ranged from < 0.01 to 0.585 microgram ml-1, while those of nestling eagles from a reference site indicated normal or background exposure (< 0.01 microgram ml-1). No differences in the prevalence of elevated exposure were detected among genders or age classes (0.5- and > or = 1.5-year-old birds) (P > 0.05). The prevalence of elevated exposure was significantly greater in November than in October (21.7 vs. 3.8%) (all years: chi 2Y = 5.75, P = 0.017). Eagles with shotshell pellets in the digestive tract did not have accompanying high PbB concentrations. The prevalence of elevated lead exposure in this study was low in comparison to other areas in North America. Potential biases in the trapping technique as they relate to interpreting the results are addressed. PMID:11234531

  8. Environmental urban lead exposure and blood lead levels in children of Mexico City.

    PubMed Central

    Romieu, I; Carreon, T; Lopez, L; Palazuelos, E; Rios, C; Manuel, Y; Hernandez-Avila, M

    1995-01-01

    Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil, water, and glazed ceramics were obtained from the participants' households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 micrograms/dl with a mean of 9.9 micrograms/dl (SD 5.8 micrograms/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 micrograms/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used to prepare children's food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children's hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics. PMID:8605853

  9. Lead uptake and lead loss in the fresh water field crab, Barytelphusa guerini, on exposure to organic and inorganic lead

    SciTech Connect

    Tulasi, S.J.; Yasmeen, R.; Reddy, C.P.; Rao, J.V.R.

    1987-07-01

    Lead is a heavy metal which is widely used in paint industry, pigments, dyes, electrical components and electronics, plastic chemicals and in various other things. Since some of the lead salts are soluble in water, lead presents a potential threat to aquatic organisms. Studies dealing with invertebrates include those on mortality, growth and lead uptake in Lymnaea palustris and bioaccumulation of heavy metals in oysters and mussels. Little information exists regarding the effect of lead on the fresh water crustaceans. Hence the present investigation has been undertaken to study the uptake and loss of lead on exposure to subtoxic levels or organic and inorganic lead.

  10. Lead level in seminal plasma may affect semen quality for men without occupational exposure to lead

    PubMed Central

    2012-01-01

    Background Infertility affects approximately 10–15% of reproductive-age couples. Poor semen quality contributes to about 25% of infertile cases. Resulting from the direct effect on testicular function or hormonal alterations, heavy metals exposure has been related to impaired semen quality. The objective of this study was to assess the level of lead in the seminal plasma in men without occupational exposure to lead, and to determine the relationship between semen quality and lead concentration in the semen. Methods This is a prospective and nonrandomized clinical study conducted in University infertility clinic and academic research laboratory. Three hundred and forty-one male partners of infertile couples undergoing infertility evaluation and management were recruited to the study. Semen samples collected for the analyses of semen quality were also used for the measurement of lead concentrations. Semen samples were evaluated according to the WHO standards. Results All subjects were married and from infertile couples without occupational exposure to lead. There is a significant inverse correlation between the lead concentration in seminal plasma and sperm count. A higher semen lead concentration was correlated with lower sperm count, but not with semen volume, sperm motility or sperm morphology as assessed by simple linear regression. Conclusions We found that semen lead concentration was significantly higher among the patients with lower sperm count. To our knowledge, this is the first study to demonstrate that a high level of lead accumulation in semen may reduce the sperm count contributing to infertility of men without occupational exposure to lead. PMID:23137356

  11. Take home lead exposure in children of oil field workers.

    PubMed

    Khan, Fahad

    2011-06-01

    Childhood lead poisoning is a major, preventable environmental health problem. While residential lead-based paint and lead contaminated dust and soil are the most common sources of childhood lead poisoning, children can also be at risk if they live with an adult with a job or hobby that involves exposure to lead. Currently, the Oklahoma Childhood Lead Poisoning Prevention Program (OCLPPP) has a small number of cases of "take home" lead exposure in children of oil field workers. These workers may come in contact with a threading compound, "pipe dope" that can contain large amounts of lead. Workers handling this product may be exposed to lead by not following safety instructions. Additionally workers may not be provided the facilities to shower and change out of the contaminated clothing before leaving the work location. The OCLPPP recommends employers and worksites should consider effective alternative options like lead free biodegradable pipe dopes or dope free connections to prevent workers and their families from adverse health effects associated with lead. PMID:21888039

  12. Lead exposure from backyard chicken eggs: a public health risk?

    PubMed

    Bautista, Adrienne C; Puschner, Birgit; Poppenga, Robert H

    2014-09-01

    Although the USA has made significant strides in reducing lead exposure, new and emerging sources are raising cause for public concern. Recent reports of finding lead in eggs from chickens raised in urban gardens has highlighted the need to consider the potential health risks of consuming eggs from backyard chickens. Following the detection of 0.33 μg/g lead in the edible portion of eggs submitted for lead analysis from a backyard chicken owner, further investigation was conducted to determine the source and extent of lead exposure in the flock. Several birds, almost two dozen eggs, and environmental samples were submitted to the California Animal Health and Food Safety Laboratory for further testing. Lead was detected in the blood, liver, kidney, and bone at varying concentrations in all birds but was not detected in the muscle tissue. All egg shells contained detectable amounts of lead, while only a little over half of the edible portion of the eggs contained lead. The detected concentrations in the edible portion approached or exceeded the recommended threshold of lead consumption per day that should not be exceeded by young children if a child consumed one average-sized egg. Peeling paint from a wooded structure adjacent to the flock's coop was the likely lead source containing 3,700 μg/g lead. Thus, removal of the chickens from the source and periodic testing of eggs for lead were recommended. This case illustrates the need for consumers and health care workers to be aware of potential sources for lead exposure such as backyard chickens. PMID:24943230

  13. Elevated blood lead levels from exposure via a radiator workshop

    SciTech Connect

    Treble, R.G.; Thompson, T.S.; Morton, D.N.

    1998-04-01

    Elevated lead levels were discovered in blood samples collected from family members where both the father and the mother worked in a radiator repair workshop. The father and mother were found to have blood lead levels of 2.0 and 0.5 {micro}mol/L, respectively. The father`s blood lead level was just below the Canadian occupational health and safety intervention level. The two children had blood lead levels of 1.0 and 0.8 {micro}mol/L, both of which are in excess of the recommended guideline for intervention in the case of children. The exposure of the two children was possibly due to a combination of pathways including exposure at the workshop itself during visits and also the transportation of lead-containing dust to the home environment.

  14. Lead exposure in the lead-acid storage battery manufacturing and PVC compounding industries.

    PubMed

    Ho, S F; Sam, C T; Embi, G B

    1998-09-01

    This study was conducted as part of the Human Exposure Assessment Location (HEAL) Project which comes under the United Nations Environment Programme/World Health Organisation (UNEP/WHO) Global environmental Monitoring System (GEMS). The objective of the study was to evaluate workers' exposure to lead in industries with the highest exposure. All subjects were interviewed about their occupational and smoking histories, the use of personal protective equipment and personal hygiene. The contribution of a dietary source of lead intake from specified foods known to contain lead locally and personal air sampling for lead were assessed. A total of 61 workers from two PVC compounding and 50 workers from two lead acid battery manufacturing plants were studied together with 111 matched controls. In the PVC compounding plants the mean lead-in-air level was 0.0357 mg/m3, with the highest levels occurring during the pouring and mixing operations. This was lower than the mean lead-in-air level of 0.0886 mg/m3 in the lead battery manufacturing plants where the highest exposure was in the loading of lead ingots into milling machines. Workers in lead battery manufacturing had significantly higher mean blood lead than the PVC workers (means, 32.51 and 23.91 mcg/100 ml respectively), but there was poor correlation with lead-in-air levels. Among the lead workers, the Malays had significantly higher blood lead levels than the Chinese (mean blood levels were 33.03 and 25.35 mcg/100 ml respectively) although there was no significant difference between the two ethnic groups in the control group. There were no significant differences between the exposed and control group in terms of dietary intake of specified local foods known to contain lead. However, Malays consumed significantly more fish than the Chinese did. There were no ethnic differences in the hours of overtime work, number of years of exposure, usage of gloves and respirators and smoking habits. Among the Malays, 94.3% eat with

  15. The cultural parameters of lead poisoning: A medical anthropologist's view of intervention in environmental lead exposure

    SciTech Connect

    Trotter, R.T. II )

    1990-11-01

    This article identifies four culturally shaped sources of lead exposure in human societies: modern and historic technological sources; food habits; culturally defined health beliefs; and beauty practices. Examples of these potential sources of lead poisoning are presented from current cultures. They include the use of lead-glazed cooking pottery in Mexican-American households; folk medical use of lead in Hispanic, Arabic, South Asian, Chinese, and Hmong communities; as well as the use of lead as a cosmetic in the Near East, Southeast Asia, and South Asia. Four interacting cultural conditions that create barriers to the reduction of lead exposure and lead poisoning are identified and discussed. These are knowledge deficiencies, communication resistance, cultural reinterpretations, and incongruity of explanatory models.

  16. The cultural parameters of lead poisoning: a medical anthropologist's view of intervention in environmental lead exposure.

    PubMed Central

    Trotter, R T

    1990-01-01

    This article identifies four culturally shaped sources of lead exposure in human societies: modern and historic technological sources: food habits; culturally defined health beliefs; and beauty practices. Examples of these potential sources of lead poisoning are presented from current cultures. They include the use of lead-glazed cooking pottery in Mexican-American households; folk medical use of lead in Hispanic, Arabic, South Asian, Chinese, and Hmong communities; as well as the use of lead as a cosmetic in the Near East, Southeast Asia, and South Asia. Four interacting cultural conditions that create barriers to the reduction of lead exposure and lead poisoning are identified and discussed. These are knowledge deficiencies, communication resistance, cultural reinterpretations, and incongruity of explanatory models. PMID:2088759

  17. Neonatal lead exposure impairs development of rodent barrel field cortex

    PubMed Central

    Wilson, Mary Ann; Johnston, Michael V.; Goldstein, Gary W.; Blue, Mary E.

    2000-01-01

    Childhood exposure to low-level lead can permanently reduce intelligence, but the neurobiologic mechanism for this effect is unknown. We examined the impact of lead exposure on the development of cortical columns, using the rodent barrel field as a model. In all areas of mammalian neocortex, cortical columns constitute a fundamental structural unit subserving information processing. Barrel field cortex contains columnar processing units with distinct clusters of layer IV neurons that receive sensory input from individual whiskers. In this study, rat pups were exposed to 0, 0.2, 1, 1.5, or 2 g/liter lead acetate in their dam's drinking water from birth through postnatal day 10. This treatment, which coincides with the development of segregated columns in the barrel field, produced blood lead concentrations from 1 to 31 μg/dl. On postnatal day 10, the area of the barrel field and of individual barrels was measured. A dose-related reduction in barrel field area was observed (Pearson correlation = −0.740; P < 0.001); mean barrel field area in the highest exposure group was decreased 12% versus controls. Individual barrels in the physiologically more active caudoventral group were affected preferentially. Total cortical area measured in the same sections was not altered significantly by lead exposure. These data support the hypothesis that lead exposure may impair the development of columnar processing units in immature neocortex. We demonstrate that low levels of blood lead, in the range seen in many impoverished inner-city children, cause structural alterations in a neocortical somatosensory map. PMID:10805810

  18. Effects of Developmental Lead Exposure on the Hippocampal Transcriptome: Influences of Sex, Developmental Period, and Lead Exposure Level

    PubMed Central

    Schneider, Jay S

    2012-01-01

    Developmental lead (Pb) exposure has profound effects on cognition and behavior. Much is known about effects of Pb on hippocampal-mediated behaviors, but little is known about the molecular consequences of Pb exposure and the influences of developmental timing of exposure, level of exposure, and sex as effect modifiers of Pb exposure on the brain. The aim of this study was to examine the effects of different levels of Pb exposure (250 and 750 ppm Pb acetate) during perinatal (gestation/lactation) and postnatal (through postnatal day 45) periods on the hippocampal transcriptome in male and female Long Evans rats. Total RNA was extracted from hippocampus from four animals per experimental condition. RNA was hybridized to Affymetrix Rat Gene RNA Arrays using standard methods. Pb exposure per se influenced the expression of 717 transcripts (328 unique annotated genes), with many influenced in a sex-independent manner. Significant differences in gene expression patterns were also influenced by timing and level of exposure, with generally larger effects at the lower level of exposure across all groups. Statistically enriched biological functions included ion binding, regulation of RNA metabolic processes, and positive regulation of macromolecule biosynthetic processes. Processes of regulation of transcription and regulation of gene expression were preferentially enriched in males, regardless of timing or amount of Pb exposure. The effect on transcription factors and the diverse pathways or networks affected by Pb suggest a substantial effect of developmental Pb exposure on plasticity and adaptability, with these effects significantly modified by sex, developmental window of exposure, and level of Pb exposure. PMID:22641619

  19. Lead exposure assessment from study near a lead-acid battery factory in China.

    PubMed

    Chen, Laiguo; Xu, Zhencheng; Liu, Ming; Huang, Yumei; Fan, Ruifang; Su, Yanhua; Hu, Guocheng; Peng, Xiaowu; Peng, Xiaochun

    2012-07-01

    The production of lead-acid battery in China covered about one-third of the world total output and there are more than 2000 lead-acid battery factories. They may cause the major environment lead pollution. Blood lead levels of several hundreds of residents were over 100 μg/L due to the waste discharges from a lead-acid battery factory in Heyuan, Guangdong province. This study aimed to find out the environmental lead sources, the human lead exposure pathways, and the amplitudes from a lead-acid battery factory. The study results showed that lead levels in soil, dust, tree leaves and human blood declined with the distances increased from the production site. Twenty nine of 32 participants had blood lead levels of over 100 μg/L with an exceptional high value of 639 μg/L for one child. This result suggested that the lead-acid battery production from this factory has caused the elevated lead levels in its neighboring environment and residents. Dust intake was the dominant exposure pathway for humans (over 90%). The lead levels found in adult and toddler (6.19 and 50.1 μg/kg/d, respectively) in the polluted area were far higher than the provisional tolerable weekly intake (PTWI) of 25 μg/kg body weight (translated into 3.5 μg/kg/d), which was established by the joint FAO/WHO Expert Committee. Blood lead levels within the family members were strongly correlated with the house dust lead levels. Our results in this study suggested that further studies in this area should be performed to assess human exposure and relevant human health risks from living close to lead-acid battery factories. PMID:22578522

  20. Neurotoxic Effects and Biomarkers of Lead Exposure: A Review

    PubMed Central

    Sanders, Talia; Liu, Yiming; Buchner, Virginia; Tchounwou, Paul B.

    2010-01-01

    Biological monitoring techniques are useful for risk assessment of toxic agents in the field of environmental health. Lead, a systemic toxicant affecting virtually every organ system, primarily affects the central nervous system, particularly the developing brain. Consequently, children are at a greater risk than adults of suffering from the neurotoxic effects of lead. The ability of lead to pass through the blood-brain barrier is due in large part to its ability to substitute for calcium ions. Within the brain, lead-induced damage in the prefrontal cerebral cortex, hippocampus, and cerebellum can lead to a variety of neurological disorders, such as brain damage, mental retardation, behavioral problems, nerve damage, and possibly Alzheimer’s disease, Parkinson’s disease, and schizophrenia. At the molecular level, lead interferes with the regulatory action of calcium on cell functions and disrupts many intracellular biological activities. Experimental studies have also shown that lead exposure may have genotoxic effects, especially in the brain, bone marrow, liver, and lung cells. This paper presents an overview of biomarkers of lead exposure and discusses the neurotoxic effects of lead with regard to children, adults, and experimental animals, updated to January 2009. PMID:19476290

  1. CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS.

    EPA Science Inventory

    CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS. ME Gilbert1, ME Kelly2, S. Salant3, T Shafer1, J Goodman3 1Neurotoxicology Div, US EPA, RTP, NC, 27711, 2Children's Hospital, Philadelphia, PA, 19104, 3Helen Hayes Hospital, Haverstraw, NY, 10993.
    ...

  2. Lead exposure among five distinct occupational groups: a comparative study.

    PubMed

    Gharaibeh, Mohammad Younis; Alzoubi, Karem Hasan; Khabour, Omar Falah; Khader, Yousef Saleh; Gharaibeh, Mamoun Abdallah; Matarneh, Sulaiman Khalid

    2014-01-01

    This study was conducted to evaluate blood lead concentration among five selected occupational groups. The five groups were: hospital health workers, shop workers, taxi drivers, automobiles mechanics, and wood workers. The groups did not significantly differ among each other in the average of age and work years. ANOVA test revealed significantly higher mean lead blood concentration in taxi drivers, automechanics, and wood workers compared to other groups. Additionally, workers with lead concentration >0.483 umol/L (10μg/dL) were more likely to have frequent muscle pain compared to those with lower concentrations. No association between other symptoms of lead exposure/toxicity and blood lead concentration was detected. In conclusion, special attention must be directed toward lead blood levels and lead poisoning symptoms when examining patients from certain occupational groups such as taxi drivers, automechanics, and wood workers. Special safety precautions and educational programs are also needed to limit the lead exposure in these occupational groups. PMID:24374433

  3. Public health. Childhood lead exposure in Wisconsin in 1990

    SciTech Connect

    Schirmer, J.; Anderson, H.; Peterson, D.E. )

    1991-01-01

    It will take the cooperation of many people to address the issue of lead poisoning. The recent death has dramatized the problem of high dose exposures. But a larger challenge is posed by the fact that most preschool children in Wisconsin are not screened for lead and as a result many asymptomatic children without signs of pica behavior will experience subtle neurological damage as a result of low to moderate elevations of lead in blood. Because many of these cases occur in children without recognized pica behavior, doctors need to expand screening, especially during well child visits, to identify children with elevated blood lead levels. Additionally, the public health community and property owners need to evaluate and control sources of lead. Major efforts are needed to address the lead hazards which now impair hundreds of Wisconsin children each year.

  4. Hypertension`s lead connection: Does low-level exposure to lead cause high blood pressure?

    SciTech Connect

    Fackelmann, K.

    1996-06-15

    {open_quotes}Paying for the sins of the past.{close_quotes} is how researcher Howard Hu describes a proposed disease process in which lead stored for decades in the skeleton puts people at risk of high blood pressure. Previous research has linked this silvery white, poisonous metal to a host of ill effects in children, including learning disabilities, behavior problems, and brain damage. Now, Hu`s study indicates that past exposure may be causing today`s high blood pressure. If he`s right, the public health impact would be significant. {open_quotes}Tens of millions of Americans have been exposed over the years to lead,{close_quotes} says Philip J. Landrigan of Mount Sinai Medical Center in New York. {open_quotes}Adults today grew up at a time when we were still putting several hundred thousand tons of lead into gasoline each year.{close_quotes} Indeed, the men who developed high blood pressure during the recent study had in their bones lead concentrations, or lead burdens, that came from decades of everyday exposure. Such exposures resulted principally from breathing in fumes from leaded gasoline, drinking tap water from lead pipes or pipes soldered with lead, and inhaling or ingesting lead-laced paint dust or chips. This article goes on to discuss other studies and questions which still need to be answered.

  5. Effect of prenatal and neonatal exposure to lead on gonadotropin receptors and steroidogenesis in rat ovaries

    SciTech Connect

    Wiebe, J.P.; Barr, K.J.; Buckingham, K.D.

    1988-01-01

    Sprague-Dawley rats were treated with lead chloride (20 or 200 ppm) or sodium chloride (controls) in their drinking water, either prior to pregnancy or during pregnancy and lactation, and female offspring were examined at weaning (21 d) or at 150 d. Other female rats were treated from d 21 to 35. Tissue (blood, kidney, bone) lead levels, body, ovary, and uterus weights, ovarian steroidogenesis, and gonadotropin (luteinizing hormone and follicle-stimulating hormone) levels, and gonadotropin-receptor binding were determined. Prenatal and/or postnatal exposure to lead at these levels (20 and 200 ppm) did not affect tissue weights but did cause a significant decrease in gonadotropin-receptor binding in the prepubertal, pubertal and adult females. Conversion of progesterone to androstenedione and dihydrotestosterone was significantly decreased in 21-d-old rats; in 150-d-old females, the prenatal and/or postnatal exposure to lead resulted in significantly increased conversion to the 5-alpha-reduced steroid, normally high during puberty. The results demonstrate that lead exposure prior to mating may affect gonadotropin-receptor binding in the offspring and that lead exposure (in utero, via mother's milk, or post weaning) may significantly alter steroid production and gonadotropin binding in ovaries of the prepubertal, pubertal, and adult female.

  6. Opposite effects of lead exposure on taurine- and HFS-induced LTP in rat hippocampus.

    PubMed

    Yu, Kuai; Yu, Shan-Shan; Ruan, Di-Yun

    2005-01-30

    The effect of lead exposure on taurine-induced long-term potentiation (LTP(TAU)) was examined and compared with high-frequency stimulation-induced one (LTP(HFS)). Field excitatory postsynaptic potentials (fEPSP) and fiber volley (FV) in area CA1 of hippocampal slice were recorded in control and lead-exposed rats. In contrast to the inhibitory effects of lead exposure on LTP(HFS), the amplitude of LTP(TAU) in the lead-exposed rats (199.3+/-13.7%, n=12) was significantly larger than that in controls (152.3+/-17.0%, n=12). It was also observed that taurine induced greater FV potentiation in lead-exposed rats (162.6+/-9.0%, n=10) than controls (132.1+/-6.9%, n=11). In addition, after a previous HFS, sequent perfusion of taurine could further increase the synaptic efficacy in lead-exposed rats. These results provide the first evidence that chronic lead exposure has opposite effects on the two types of LTP resulting from different lead toxicity sites. PMID:15639549

  7. Census tract analysis of lead exposure in Rhode Island children.

    PubMed

    Sargent, J D; Bailey, A; Simon, P; Blake, M; Dalton, M A

    1997-01-01

    There has been increasing interest in a targeted approach to the screening and prevention of lead exposure in children. Targeted screening requires an understanding of variation in lead exposure in individual children or by region. In order to better understand variation by region, we studied Rhode Island lead poisoning screening data, examining average lead exposure to children living in 136 Providence County census tracts (CTs). The study population included 17,956 children aged 59 months and under, who were screened between May 1, 1992, and April 30, 1993. We evaluated the relationship between the percentage of children with blood lead > or = 10 micrograms/dL (pe10) and sociodemographic and housing characteristics, derived from United States 1990 Census data, of these CTs. CT descriptors included population density, percentage of households receiving public assistance income, median per capita income, percentage of households female headed, percentage of houses owner occupied, percentage of houses built before 1950, percentage of houses vacant, percentage of population Black, percentage of recent immigrants, and intraurban mobility. On average, 109 children were screened in each census tract; mean screening rate was 44%. There was wide variation in average lead exposure among census tracts, with pe10 ranging from 3 to 60% of screened children (mean 27%). Individual census variables explained between 24 and 67% of the variance in pe10 among CTs. A multiple regression model including percentage screened, percentage of households receiving public assistance, percentage of houses built before 1950, In (percentage of houses vacant), and percentage of recent immigrants explained 83% of variance in pe10. The percentage of houses built before 1950, a variable which models the presence of lead paint in old houses, displayed the largest adjusted effect on pe10 over the range observed for that variable in RI CTs. The percentage of houses vacant was also a highly

  8. Chronic Lead Poisoning From Industrial Exposure: A Review

    PubMed Central

    Yassi, Annalee

    1980-01-01

    Lead poisoning from chronic industrial exposure is not uncommon. Early diagnosis is important in avoiding irreversible effects. A good occupational history is key to alerting the unsuspecting physician to the correct diagnosis. Blood lead levels are useful but ridden with shortcomings. Specific tests to assess functional impairment, such as urinary aminolevulinic acid (ALA) and coproporphyrins should be included in the diagnostic work-up. Lead poisoning is a preventable disease well worth the consideration of the family practitioner. (Can Fam Physician 1980; 26:1056-1062). PMID:21293668

  9. Leaded crystal as a source of dietary lead: An exposure assessment

    SciTech Connect

    Shorten, C.V.; Glowacki, M.L.

    1995-12-31

    Lead is a potent systemic toxic with many environmental sources. It can enter the body through a number of pathways, the most significant is ingestion. While many investigators of lead ingestion have focused on paint and dust sources, the authors examined food contaminated with lead from crystal ware. The rates and amounts of lead leached into vinegar stored in leaded crystal cruets were measured over the course of a 42-day laboratory study. Replicate lead oxide (PbO, 24%) crystal cruets (N = 13) were filled with vinegar, and sample aliquots were periodically removed for analysis. Lead leaching rates were determined by fitting a two-stage, non-linear model to the data, and observed rate coefficients were 0.066 hr{sup {minus}1} and 0.0019{sup {minus}1} for the first and second stages of leaching, respectively (R{sup 2} = 0.9680). Average lead concentrations in the stored vinegar range from 118 {micro}g/L at 8 parameters (ingestion rate, exposure frequency and duration, body weight, and averaging time) was generated to characterize the realm of potential intake estimates. Lead concentrations were input using the fitted model. Results indicated that a worst case lead intake estimate from this source could be as high as 420 {micro}g/kg/yr for a child. Crystal ware can be considered to be a potentially significant dietary source of lead, and risk characterizations cannot ignore this potential avenue when combining risks across all exposure pathways.

  10. Environmental and Occupational Lead Exposure Among Children in Cairo, Egypt

    PubMed Central

    Moawad, Eman Mohamed Ibraheim; Badawy, Nashwa Mostafa; Manawill, Marie

    2016-01-01

    Abstract The aim of this study was to assess childhood lead exposure in a representative sample of Cairo, and to investigate the possible risk factors and sources of exposure. This cross-sectional study was conducted from November 2014 through April 2015. The target population was children aged 6 to 18 years, recruited into 4 groups, garbage city, moderate-living standard area, urban and suburban schools, and workshops in the city of Cairo. Blood lead levels (BLLs) and hemoglobin (Hb) concentrations were measured. Also, potential local environmental sources were assessed for hazardous lead contamination. Analysis on 400 participants has been carried out. A total of 113 children had BLLs in the range 10 to 20 μg/dL. Smoking fathers, housing conditions, playing outdoors, and exposure to lead in residential areas were significantly correlated with high BLLs. The mean values of hemoglobin were inversely correlated with BLLs. Children involved in pottery workshops had the highest BLLs and the lowest Hb values with a mean of (43.3 μg/dL and 8.6 g/dL, respectively). The mean value of environmental lead in workshop areas exceeded the recommended levels. Also, those values measured in dust and paint samples of garbage city were significantly high. Moreover, the mean lead levels in the soil samples were significantly higher in urban schools (P = 0.03) than the suburban ones. Childhood lead poisoning accounts for a substantial burden in Egypt, which could be preventable. Development of national prevention programs including universal screening program should be designed to reduce incidence of lead toxicity among children. PMID:26945415

  11. Proton Magnetic Resonance Spectroscopy in Adults with Childhood Lead Exposure

    PubMed Central

    Cecil, Kim M.; Dietrich, Kim N.; Altaye, Mekibib; Egelhoff, John C.; Lindquist, Diana M.; Brubaker, Christopher J.; Lanphear, Bruce P.

    2011-01-01

    Background Childhood lead exposure adversely affects neurodevelopment. However, few studies have examined changes in human brain metabolism that may underlie known adverse cognitive and behavioral outcomes. Objective We examined the association between mean childhood blood lead levels and in vivo brain metabolite concentrations as adults, determined by proton magnetic resonance spectroscopy (MRS) in a birth cohort with documented low-to-moderate lead exposure. Methods Adult participants from the Cincinnati Lead Study [n = 159; mean age (± SD), 20.8 ± 0.9 years] completed a quantitative, short-echo proton MRS protocol evaluating seven regions to determine brain concentrations of N-acetyl aspartate (NAA), creatine and phosphocreatine (Cr), cholines (Cho), myo-inositol, and a composite of glutamate and glutamine (GLX). Correlation and multiple linear regression analyses were conducted. Results Mean childhood blood lead levels were associated with regionally specific brain metabolite concentrations adjusted for age at imaging and Full-Scale intelligence quotient. Adjusted analyses estimated for a unit (micrograms per deciliter) increase in mean childhood blood lead concentrations, a decrease of NAA and Cr concentration levels in the basal ganglia, a decrease of NAA and a decrease of Cho concentration levels in the cerebellar hemisphere, a decrease of GLX concentration levels in vermis, a decrease of Cho and a decrease of GLX concentration levels in parietal white matter, and a decrease of Cho concentration levels in frontal white matter. Conclusions Gray-matter NAA reductions associated with increasing childhood blood lead levels suggest that sustained childhood lead exposure produces an irreversible pattern of neuronal dysfunction, whereas associated white-matter choline declines indicate a permanent alteration to myelin architecture. PMID:20947467

  12. Lead exposure and hair lead level of workers in a lead refinery industry in Iran

    PubMed Central

    Pirsaraei, Seyed Reza Azimi

    2007-01-01

    This study was carried out on the workers of a lead refinery industry and two control groups in Zanjan city in Iran. The scalp hair samples were collected from 25 workers who were occupationally exposed to lead contamination as a case group and from 25 subjects among the staff of the same industry and 25 subjects among Zanjan citizens as the first and second control groups respectively. A flame atomic absorption spectrophotometer used to determine lead level in all of the samples. The age of all subjects in the three groups was matched. The mean concentrations of hair lead in the workers (case group), the staff (control groupA) and the citizens (control group B) were 131.7±93.4 µgr/gr, 21.1±13.2 µgr/gr and 27.9±14.1 µgr/gr respectively. The mean concentration of hair lead in the case group was more than hair lead of normal range found in humans (0-30 µgr/gr). The mean of hair lead level in the citizens who had used gas vehicles was statistically higher than who had not used it (36.9±12.2 µgr/gr vs. 16.6±4.9 µgr/gr, P<0.001). PMID:21957365

  13. Child lead-exposure study, Leeds, Alabama. Final report

    SciTech Connect

    Woernle, C.; Rao, R.; White, J.; Amler, R.

    1991-09-01

    In August 1989, a human exposure study was undertaken near a secondary battery lead reclamation factory in Leeds, Alabama. A door-to-door census survey was conducted in two targeted residential areas near the factory. Venous blood samples were analyzed for lead, erthrocyte protoporphyrin, hemoglobin, and hematocrit. Among 81 children (9-71 months) studied the mean blood lead value was 6.96 micrograms per deciliter (mcg/dl), with a range of 3 to 16 mcg/dl; 85% of the values were below 10 mcg/dl. A multivariate linear regression model and a logistic regression model identified several following factors as being associated with an increased blood lead value or, having a blood lead concentration in the upper 15th percentile (>10 mcg/dl).

  14. Exposure to lead of boatyard workers in southern Thailand.

    PubMed

    Thanapop, Chamnong; Geater, Alan F; Robson, Mark G; Phakthongsuk, Pitchaya; Viroonudomphol, Duangkamol

    2007-09-01

    Lead oxide is used extensively in the construction and repair of wooden boats in Thailand, but the behaviors of boatyard workers that could place them at risk of contamination have not previously been documented. Baseline data on practices and behaviors of boatyard workers and on the level of worker and workplace contamination with lead were therefore collected. Fifty workers in two boatyards participated in this study. Lead exposure of workers was assessed by determining airborne and blood lead levels. A questionnaire was administered to collect information on work history, suspected exogenous lead sources, personal behavior and knowledge about lead. Evidence obtained by the study indicated that safety behavior and personal hygiene were poor--workers used no mask, gloves or hood, wore open sandals, smoked, drank, chewed and ate during work and did not wash their hands before drinking or eating. Some workers had lunch in the working area. The mean personal airborne lead of caulkers (36.4 microg/m3) was higher than that of carpenters (8.3 microg/m3). Forty-eight percent of all workers and 67% of caulkers had a blood lead level (BLL) exceeding 40 microg/dl. Multiple linear regression indicated that blood lead levels of workers were significantly related to job and education level, with significant differences between boatyards. In addition, the potential for "take-home" contamination was high; none of the workers took a shower or changed their clothes prior to going home. These results indicate a problem of lead exposure of sufficient magnitude to be a public health concern. PMID:17951965

  15. Prenatal lead exposure, delta-aminolevulinic acid, and schizophrenia.

    PubMed Central

    Opler, Mark G A; Brown, Alan S; Graziano, Joseph; Desai, Manisha; Zheng, Wei; Schaefer, Catherine; Factor-Litvak, Pamela; Susser, Ezra S

    2004-01-01

    Schizophrenia is a severe mental disorder of unknown etiology. Recent reports suggest that a number of environmental factors during prenatal development may be associated with schizophrenia. We tested the hypothesis that environmental lead exposure may be associated with schizophrenia using archived serum samples from a cohort of live births enrolled between 1959 and 1966 in Oakland, California. Cases of schizophrenia spectrum disorder were identified and matched to controls. A biologic marker of lead exposure, delta-aminolevulinic acid (delta-ALA), was determined in second-trimester serum samples of 44 cases and 75 controls. delta-ALA was stratified into high and low categories, yielding 66 subjects in the high category, corresponding to a blood lead level (BPb) greater than or equal to 15 micro g/dL, and 53 in the low category, corresponding to BPb less than 15 micro g/dL. Using logistic regression, the odds ratio (OR) for schizophrenia associated with higher delta-ALA was 1.83 [95% confidence interval (CI), 0.87-3.87; p = 0.1]. Adjusting for covariates gave an OR of 2.43 (95% CI, 0.99-5.96; p = 0.051). This finding suggests that the effects of prenatal exposure to lead and/or elevated delta-ALA may extend into later life and must be further investigated as risk factors for adult psychiatric diseases. PMID:15064159

  16. Influence of the degree of exposure to lead on relations between alcohol consumption and the biological indices of lead exposure: epidemiological study in a lead acid battery factory.

    PubMed

    Cezard, C; Demarquilly, C; Boniface, M; Haguenoer, J M

    1992-09-01

    Alcohol has been shown to interact with lead to influence haem biosynthesis. The aim of this study was to define the dependence of this interaction on the degree of exposure to lead. Exposure to alcohol was estimated by measurement of alcohol concentrations in a sample of urine collected during the morning (AlcUM) (0.82 (SD 4.36) mmol/l) and in a sample collected during the afternoon (AlcUA) (1.15 (SD 3.49) mmol/l). The biological monitoring of exposure to lead included measurements of blood lead (Pb-B) (1.82 (SD 0.72) mumol/l), urinary delta-aminolaevulinic acid (ALAU) (35.33 (SD 28.00) mumol/l; d = 1.015), and erythrocyte zinc-protoporphyrin (ZPP) (112.90 (SD 83.71) nmol/mmol Hb) concentrations. The study of the influence of the degree of occupational exposure to lead on relations between alcohol consumption and effects of the exposure to lead led to the consideration of two different groups--namely, mildly and strongly exposed subjects. In the first group, individual biological susceptibility seemed to play a preponderant part. In the second, the pool of lead present in the body seemed to be sufficiently important to mask the effects of individual susceptibility. PMID:1390270

  17. A novel lead design enables selective deep brain stimulation of neural populations in the subthalamic region

    NASA Astrophysics Data System (ADS)

    van Dijk, Kees J.; Verhagen, Rens; Chaturvedi, Ashutosh; McIntyre, Cameron C.; Bour, Lo J.; Heida, Ciska; Veltink, Peter H.

    2015-08-01

    Objective. The clinical effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) as a treatment for Parkinson’s disease are sensitive to the location of the DBS lead within the STN. New high density (HD) lead designs have been created which are hypothesized to provide additional degrees of freedom in shaping the stimulating electric field. The objective of this study is to compare the performances of a new HD lead with a conventional cylindrical contact (CC) lead. Approach. A computational model, consisting of a finite element electric field model combined with multi-compartment neuron and axon models representing different neural populations in the subthalamic region, was used to evaluate the two leads. We compared ring-mode and steering-mode stimulation with the HD lead to single contact stimulation with the CC lead. These stimulation modes were tested for the lead: (1) positioned in the centroid of the STN, (2) shifted 1 mm towards the internal capsule (IC), and (3) shifted 2 mm towards the IC. Under these conditions, we quantified the number of STN neurons that were activated without activating IC fibers, which are known to cause side-effects. Main results. The modeling results show that the HD lead is able to mimic the stimulation effect of the CC lead. Additionally, in steering-mode stimulation there was a significant increase of activated STN neurons compared to the CC mode. Significance. From the model simulations we conclude that the HD lead in steering-mode with optimized stimulation parameter selection can stimulate more STN cells. Next, the clinical impact of the increased number of activated STN cells should be tested and balanced across the increased complexity of identifying the optimized stimulation parameter settings for the HD lead.

  18. Protoporphyrin (FEP/ZPP) screening in industrial lead exposure

    SciTech Connect

    Saryan, L.A.

    1988-11-01

    Lead-acid battery manufacturers, as a group, are among the largest industrial users of lead in the United States, and every industry using this metal is confronted with a maze of federal regulations governing workplace conditions and employee health. In the biological testing category, particular emphasis has been placed on the periodic testing of blood for lead, to assess absorption of the metal, and protoporphyrin (abbreviated ZPP or FEP) testing as a means of monitoring the biological effects resulting from lead exposure. The protoporphyrin test, however, remains a matter of general confusion among industry managers and medical directors, and this article attempts to provide a concise and understandable explanation of this topic. 10 references, 3 figures, 1 table.

  19. Stimulation of erythrocyte phosphatidylserine exposure by mercury ions

    SciTech Connect

    Eisele, Kerstin; Lang, Philipp A.; Kempe, Daniela S.; Klarl, Barbara A.; Niemoeller, Olivier; Wieder, Thomas; Huber, Stephan M.; Duranton, Christophe; Lang, Florian . E-mail: florian.lang@uni-tuebingen.de

    2006-01-15

    The sequelae of mercury intoxication include induction of apoptosis. In nucleated cells, Hg{sup 2+}-induced apoptosis involves mitochondrial damage. The present study has been performed to elucidate effects of Hg{sup 2+} in erythrocytes which lack mitochondria but are able to undergo apoptosis-like alterations of the cell membrane. Previous studies have documented that activation of a Ca{sup 2+}-sensitive erythrocyte scramblase leads to exposure of phosphatidylserine at the erythrocyte surface, a typical feature of apoptotic cells. The erythrocyte scramblase is activated by osmotic shock, oxidative stress and/or energy depletion which increase cytosolic Ca{sup 2+} activity and/or activate a sphingomyelinase leading to formation of ceramide. Ceramide sensitizes the scramblase to Ca{sup 2+}. The present experiments explored the effect of Hg{sup 2+} ions on erythrocytes. Phosphatidylserine exposure after mercury treatment was estimated from annexin binding as determined in FACS analysis. Exposure to Hg{sup 2+} (1 {mu}M) indeed significantly increased annexin binding from 2.3 {+-} 0.5% (control condition) to 23 {+-} 6% (n = 6). This effect was paralleled by activation of a clotrimazole-sensitive K{sup +}-selective conductance as measured by patch-clamp recordings and by transient cell shrinkage. Further experiments revealed also an increase of ceramide formation by {approx}66% (n = 7) after challenge with mercury (1 {mu}M). In conclusion, mercury ions activate a clotrimazole-sensitive K{sup +}-selective conductance leading to transient cell shrinkage. Moreover, Hg{sup 2+} increases ceramide formation. The observed mechanisms could similarly participate in the triggering of apoptosis in nucleated cells by Hg{sup 2+}.

  20. Blood Lead Concentration and Thyroid Function during Pregnancy: Results from the Yugoslavia Prospective Study of Environmental Lead Exposure

    PubMed Central

    Kahn, Linda G.; Liu, Xinhua; Rajovic, Biljana; Popovac, Dusan; Oberfield, Sharon; Graziano, Joseph H.

    2014-01-01

    Background: Although maternal hypothyroidism increases the risk of adverse neonatal and obstetric outcomes as well as lower IQ in children, the environmental determinants of maternal thyroid dysfunction have yet to be fully explored. Objectives: We aimed to examine associations between mid-pregnancy blood lead (BPb) and concomitant measures of thyroid function among participants in the Yugoslavia Prospective Study of Environmental Lead Exposure. Methods: As part of a population-based prospective study of two towns in Kosovo—one with high levels of environmental lead and one with low—women were recruited during the second trimester of pregnancy, at which time blood samples and questionnaire data were collected. We measured concentrations of BPb, free thyroxine (FT4), thyroid-stimulating hormone (TSH), and thyroid peroxidase antibodies (TPOAb) in archived serum samples. Results: Compared with women from the unexposed town, women from the exposed town had lower mean FT4 (0.91 ± 0.17 vs. 1.03 ± 0.16 ng/dL), higher mean TPOAb (15.45 ± 33.08 vs. 5.12 ± 6.38 IU/mL), and higher mean BPb (20.00 ± 6.99 vs. 5.57 ± 2.01 μg/dL). No differences in TSH levels were found. After adjustment for potential confounders, for each natural log unit increase in BPb, FT4 decreased by 0.074 ng/dL (95% CI: –0.10, –0.046 ng/dL), and the odds ratio for testing positive to TPOAb was 2.41 (95% CI: 1.53, 3.82). We found no association between BPb and TSH. Conclusions: Prolonged lead exposure may contribute to maternal thyroid dysfunction by stimulating autoimmunity to the thyroid gland. Citation: Kahn LG, Liu X, Rajovic B, Popovac D, Oberfield S, Graziano JH, Factor-Litvak P. 2014. Blood lead concentration and thyroid function during pregnancy: results from the Yugoslavia Prospective Study of Environmental Lead Exposure. Environ Health Perspect 122:1134–1140; http://dx.doi.org/10.1289/ehp.1307669 PMID:24866691

  1. Reproductive toxicity of low-level lead exposure in men

    SciTech Connect

    Telisman, Spomenka Colak, Bozo; Pizent, Alica; Jurasovic, Jasna; Cvitkovic, Petar

    2007-10-15

    Parameters of semen quality, seminal plasma indicators of secretory function of the prostate and seminal vesicles, sex hormones in serum, and biomarkers of lead, cadmium, copper, zinc, and selenium body burden were measured in 240 Croatian men 19-52 years of age. The subjects had no occupational exposure to metals and no known other reasons suspected of influencing male reproductive function or metal metabolism. After adjusting for age, smoking, alcohol, blood cadmium, and serum copper, zinc, and selenium by multiple regression, significant (P<0.05) associations of blood lead (BPb), {delta}-aminolevulinic acid dehydratase (ALAD), and/or erythrocyte protoporphyrin (EP) with reproductive parameters indicated a lead-related increase in immature sperm concentration, in percentages of pathologic sperm, wide sperm, round sperm, and short sperm, in serum levels of testosterone and estradiol, and a decrease in seminal plasma zinc and in serum prolactin. These reproductive effects were observed at low-level lead exposure (BPb median 49 {mu}g/L, range 11-149 {mu}g/L in the 240 subjects) common for general populations worldwide. The observed significant synergistic effect of BPb and blood cadmium on increasing serum testosterone, and additive effect of a decrease in serum selenium on increasing serum testosterone, may have implications on the initiation and development of prostate cancer because testosterone augments the progress of prostate cancer in its early stages.

  2. Effect of chronic lead exposure on kidney function in male and female rats: determination of a lead exposure biomarker.

    PubMed

    Ghorbe, F; Boujelbene, M; Makni-Ayadi, F; Guermazi, F; Kammoun, A; Murat, J; Croute, F; Soleilhavoup, J P; El-Feki, A

    2001-12-01

    Several cytotoxic chemical pollutants inducing peroxidative damages are liable to induce kidney failure. Among these pollutants we find heavy metals such as: lead, nickel, cadmium, vanadium and mercury. Lead is one of the most dangerous metals because it is widely spread in the environment, and because it may be a source of several nervous diseases. The aim of this study is to provide evidence concerning the effect of this metal on the renal function and to try to determine a storage corner in the organism which serves as an indicator of a lead intoxication. Lead acetate was administered by oral route in the drinking water to adult rats aged three months at the rate of 0.3% (P1) and 0.6% (P2). Reference rats received distilled water to drink under the same conditions. The treatment continued for 15, 30, 45, 60 and 90 days. The creatinemia, uremia, glycemia and creatinuria are determined by colorimetric techniques. Lead concentration in blood as well as the lead content of the tail are determined by atomic absorption after nitroperchloric mineralization at the liquid stage. The results showed an increase of creatinemia on the 30th day of the experiment for both sexes in (P1 and P2). The same happened for ureamia. The increase of these two parameters would indicate a renal deficiency which is confirmed by a decrease of creatinuria and urinary pH observed mainly on and after the 45th day of the experiment. An increase of the renal relative weight was noticed in P1 and P2 on the 30th day of the treatment. The determination of the concentration of lead in the blood shows that this factor increases among treated subjects in a constant way, independently of the dose and the duration of the treatment. Nevertheless, the rate increase of lead in the tail seems to be dose-dependent. In conclusion, lead administered by oral route causes a renal deficiency to the rat without distinction between males and females. In addition, the tail seems to be a reliable exposure biomarker

  3. Transcriptome Changes in Hirschfeldia incana in Response to Lead Exposure

    PubMed Central

    Auguy, Florence; Fahr, Mouna; Moulin, Patricia; El Mzibri, Mohamed; Smouni, Abdelaziz; Filali-Maltouf, Abdelkarim; Béna, Gilles; Doumas, Patrick

    2016-01-01

    Hirschfeldia incana, a pseudometallophyte belonging to the Brassicaceae family and widespread in the Mediterranean region, was selected for its ability to grow on soils contaminated by lead (Pb). The global comparison of gene expression using microarrays between a plant susceptible to Pb (Arabidopsis thaliana) and a Pb tolerant plant (H. incana) enabled the identification of a set of specific genes expressed in response to lead exposure. Three groups of genes were particularly over-represented by the Pb exposure in the biological processes categorized as photosynthesis, cell wall, and metal handling. Each of these gene groups was shown to be directly involved in tolerance or in protection mechanisms to the phytotoxicity associated with Pb. Among these genes, we demonstrated that MT2b, a metallothionein gene, was involved in lead accumulation, confirming the important role of metallothioneins in the accumulation and the distribution of Pb in leaves. On the other hand, several genes involved in biosynthesis of ABA were shown to be up-regulated in the roots and shoots of H. incana treated with Pb, suggesting that ABA-mediated signaling is a possible mechanism in response to Pb treatment in H. incana. This latest finding is an important research direction for future studies. PMID:26793211

  4. MATERNAL SELF-ESTEEM, EXPOSURE TO LEAD, AND CHILD NEURODEVELOPMENT

    PubMed Central

    Surkan, Pamela J.; Schnaas, Lourdes; Wright, Rosalind J.; Téllez-Rojo, Martha M.; Lamadrid-Figueroa, Héctor; Hu, Howard; Hernández-Avila, E. Mauricio; Bellinger, David C.; Schwartz, Joel; Perroni, Estela; Wright, Robert O.

    2008-01-01

    The notion that maternal personality characteristics influence cognitive development in their children has been grounded in stress moderation theory. Maternal personality traits, such as self-esteem, may buffer maternal stressors or lead to improved maternal-child interactions that directly impact neurodevelopment. This can be extended to suggest that maternal personality may serve to attenuate or exacerbate the effects of other neurotoxicants, although this has not been studied directly. We examined whether mothers’ self-esteem had a direct or main effect on their children's cognitive outcomes. We also explored the modifying effects of maternal self-esteem on the association between exposure to lead and neurodevelopment in these children. Study participants included 379 mother-child pairs from Mexico City. Data included the Coopersmith self-esteem scale in mothers, children's Bayley's Scale of Infant Development (BSID) scores, and sociodemographic information. Linear regression was used to model the relationship between maternal self-esteem and the Bayley's Mental Development Index (MDI) and Psychomotor Development Index (PDI) scores at age 24 months using regression models stratified by levels of maternal self-esteem. In adjusted models, each point increase in maternal self-esteem was associated with children having 0.2 higher score on the Bayley's MDI (p=0.04). Similar results were observed using the PDI outcome. Moreover, there was evidence that maternal self-esteem attenuated the negative effects of lead exposure, although the interaction fell short of conventional levels of statistical significance. PMID:18261800

  5. Occupational Lead Exposure from Indoor Firing Ranges in Korea

    PubMed Central

    Lee, Suk-Ho; Lee, Se-Ho; Yoon, Hye-Sik

    2016-01-01

    Military personnel often use ammunitions that contain lead. The present study aimed to identify the risks for lead exposure and lead poisoning among workers at indoor firing ranges. A special health examination, including blood lead level (BLL) testing, was performed for all 120 workers at the indoor firing ranges of the Republic of Korea’s Air Force, Navy, and Armed Forces Athletic Corps. The overall mean BLL was 11.3 ± 9.4 µg/dL (range: 2.0–64.0 µg/dL). The arithmetic mean of the BLL for professional shooters belong to Armed Forces Athletic Corps was 14.0 ± 8.3 µg/dL, while those of shooting range managers and shooting range supervisors were 13.8 ± 11.1 µg/dL and 6.4 ± 3.1 µg/dL, respectively. One individual had a BLL of 64 µg/dL, and ultimately completed chelation treatment (with CaNa2-ethylenediaminetetraacetic acid) without any adverse effects. These findings indicate that indoor firing range workers are exposed to elevated levels of lead. Therefore, when constructing an indoor firing range, a specialist should be engaged to design and assess the ventilation system; and safety guidelines regarding ammunition and waste handling must be mandatory. Moreover, workplace environmental monitoring should be implemented for indoor firing ranges, and the workers should undergo regularly scheduled special health examinations. PMID:27051231

  6. Occupational Lead Exposure from Indoor Firing Ranges in Korea.

    PubMed

    Park, Won-Ju; Lee, Suk-Ho; Lee, Se-Ho; Yoon, Hye-Sik; Moon, Jai-Dong

    2016-04-01

    Military personnel often use ammunitions that contain lead. The present study aimed to identify the risks for lead exposure and lead poisoning among workers at indoor firing ranges. A special health examination, including blood lead level (BLL) testing, was performed for all 120 workers at the indoor firing ranges of the Republic of Korea's Air Force, Navy, and Armed Forces Athletic Corps. The overall mean BLL was 11.3 ± 9.4 µg/dL (range: 2.0-64.0 µg/dL). The arithmetic mean of the BLL for professional shooters belong to Armed Forces Athletic Corps was 14.0 ± 8.3 µg/dL, while those of shooting range managers and shooting range supervisors were 13.8 ± 11.1 µg/dL and 6.4 ± 3.1 µg/dL, respectively. One individual had a BLL of 64 µg/dL, and ultimately completed chelation treatment (with CaNa2-ethylenediaminetetraacetic acid) without any adverse effects. These findings indicate that indoor firing range workers are exposed to elevated levels of lead. Therefore, when constructing an indoor firing range, a specialist should be engaged to design and assess the ventilation system; and safety guidelines regarding ammunition and waste handling must be mandatory. Moreover, workplace environmental monitoring should be implemented for indoor firing ranges, and the workers should undergo regularly scheduled special health examinations. PMID:27051231

  7. Impact of chronic lead exposure on selected biological markers.

    PubMed

    Jangid, Ambica P; John, P J; Yadav, D; Mishra, Sandhya; Sharma, Praveen

    2012-01-01

    Lead poisoning remains a major problem in India due to the lack of awareness of its ill effects among the clinical community. Blood lead, δ-aminolevulinic acid dehydratase (δ-ALAD) and zinc protoporphyrin (ZPP) concentrations are widely used as biomarkers for lead toxicity The present study was designed to determine the impact of chronic lead exposure on selected biological markers. A total of 250 subjects, of both sexes, ranging in age from 20 to 70 years, were recruited. On the basis of BLLs, the subjects were categorized into four groups: Group A (BLL: 0-10 μg/dl), Group B (BLL: 10-20 μg/dl). Group C (BLL: 20-30 μg/dl) and Group D (BLL: 30-40 μg/dl) having BLLs of 3.60 ± 2.71 μg/dl, 15.21 ± 2.65 μg/dl, 26.82 ± 2.53 μg/dl and 36.38 ± 2.83 μg/dl, respectively. Significant changes in biological markers due to elevated BLLs were noted. The relation of BLL and biological markers to demographic characteristics such as sex, habits, diet and substances abuse (smoking effect) were also studied in the present investigation. Males, urban population, non-vegetarians, and smokers had higher blood lead levels. δ-ALAD activity was found to be significantly lower with increased BLL (P < 0.001), while the ZPP level was significantly higher with increased BLL (P < 0.001). Further, BLL showed a negative correlation with δ-ALAD (r = -0.425, P < 0.001, N = 250) and a positive correlations with ZPP (r = 0.669, P < 0.001, N = 250). Chronic lead exposure affects the prooxidant-antioxidant equilibrium leading to cellular oxidative stress. PMID:23277717

  8. Cadmium, lead and mercury exposure in non smoking pregnant women

    SciTech Connect

    Hinwood, A.L.; Callan, A.C.; Ramalingam, M.; Boyce, M.; Heyworth, J.; McCafferty, P.; Odland, J.Ø.

    2013-10-15

    Recent literature suggests that exposure to low concentrations of heavy metals may affect both maternal and child health. This study aimed to determine the biological heavy metals concentrations of pregnant women as well as environmental and dietary factors that may influence exposure concentrations. One hundred and seventy three pregnant women were recruited from Western Australia, each providing a sample of blood, first morning void urine, residential soil, dust and drinking water samples. Participants also completed a questionnaire which included a food frequency component. All biological and environmental samples were analysed for heavy metals using ICP-MS. Biological and environmental concentrations of lead and mercury were generally low (Median Pb Drinking Water (DW) 0.04 µg/L; Pb soil <3.0 µg/g; Pb dust 16.5 µg/g; Pb blood 3.67 µg/L; Pb urine 0.55; µg/L Hg DW <0.03; Hg soil <1.0 µg/g; Hg dust <1.0 µg/g; Hg blood 0.46 µg/L; Hg urine <0.40 µg/L). Cadmium concentrations were low in environmental samples (Median CdDW 0.02 µg/L; Cdsoil <0.30 ug/g; Cddust <0.30) but elevated in urine samples (Median 0.55 µg/L, creatinine corrected 0.70 µg/g (range <0.2–7.06 µg/g creatinine) compared with other studies of pregnant women. Predictors of increased biological metals concentrations in regression models for blood cadmium were residing in the Great Southern region of Western Australia and not using iron/folic acid supplements and for urinary cadmium was having lower household annual income. However, these factors explained little of the variation in respective biological metals concentrations. The importance of establishing factors that influence low human exposure concentrations is becoming critical in efforts to reduce exposures and hence the potential for adverse health effects. -- Highlights: • Biological heavy metals concentrations in women in their 3rd trimester of pregnancy. • Exposure assessment including environmental, lifestyle and activity

  9. Potential Mechanism Leading to Impaired Thermoregulation Following Microgravity Exposure

    NASA Technical Reports Server (NTRS)

    Crandall, C. G.; Etzel, R. A.

    1999-01-01

    Prolonged exposure to microgravity or its analogues impairs thermoregulation in humans evidenced by higher internal temperatures following the exposure during a thermal challenge. Although the mechanism leading to this response has not been clearly delineated, we identified that prolonged head-down tilt (HDT) markedly impairs thermoregulatory reflex control of skin blood flow, as demonstrated by an increased internal temperature threshold for cutaneous vasodilation, and by a reduced slope of the relationship between the elevation in skin blood flow relative to the elevation in internal temperature. Recently, Fortney et al. identified similar responses in two individuals following 115 days of microgravity exposure. One possible mechanism leading to altered cutaneous vasodilation during a thermal challenge following actual or simulated microgravity exposure may be associated with baroreflex-mediated attenuation in the elevation of skin blood flow. During a heat stress the elevation in skin blood flow is accomplished through a combination of increased cutaneous vascular conductance and cardiac output, both of which result in central venous pressure (CVP) decreasing 2-6 mmHg. Reductions in CVP of this magnitude in normothermia decrease muscle blood flow and skin blood flow presumably through unloading the cardiopulmonary baroreceptors. It is unclear whether the reduction in CVP, and accompanying cardiopulmonary baroreceptor unloading, during passive heating buffers the elevation in skin blood flow. That is, would the elevation in skin blood flow be greater if CVP did not decrease, or decreased to a lesser extent during the heat stress? Conversely, if CVP decreased to a greater extend during a thermal challenge following a perturbation such as prolonged HDT, would the elevation in skin blood flow be attenuated during that thermal challenge? Given that prolonged HDT decreases plasma volume and central venous pressure, such a finding would provide a plausible hypothesis

  10. Relative contribution of lead from anthropogenic sources to the total human lead exposure in the United States. Final report

    SciTech Connect

    Elias, R.W.

    1986-08-01

    The paper evaluates human exposure to lead at a baseline level for persons living in non-urban communities away from stationary or mobile sources of lead, eating typical diets, and engaging in no lead-related occupational or avocational activities. Relative contributions of atmospheric and metallic lead are evaluated for each exposure pathway. For this baseline situation, perhaps 40 to 55% of the total human exposure to lead is of atmospheric origin. Beyond the baseline level, additional exposure factors can be determined for other environments (e.g. urban, occupational, smelter communities) and for certain habits and activities (e.g., pica, smoking, drinking, and various hobbies), with variations for age, sex, or socioeconomic status. Although quantification of these factors is uncertain, they provide guidelines in determining relative exposures under differing environmental conditions. The added exposure factors can also be partitioned into atmospheric, metallic, and pigment lead.

  11. The Influence of Lead Exposure and Toxicity to Children's Neurological Development and School Performance.

    ERIC Educational Resources Information Center

    Kimball, Sarah L.

    This report discusses the effects of lead exposure and toxicity on children's cognitive development and school performance and addresses the role of schools in prevention of lead poisoning. Sources of lead exposure include mining, smelting and refining activities, lead paint, leaded gasoline, and industrial emissions. The results of lead poisoning…

  12. Radiation exposure benefit of a lead cap in invasive cardiology

    PubMed Central

    Kuon, E; Birkel, J; Schmitt, M; Dahm, J B

    2003-01-01

    Background: Occupational head exposure to radiation in cardiologists may cause radiation induced cataracts and an increased risk of brain cancer. Objective: To determine the effectiveness of 0.5 mm lead equivalent caps, not previously used in invasive cardiology, in comparison with a 1.0 mm lead equivalent ceiling mounted lead glass screen. Design: An anthropomorphic Alderson-Rando phantom was used to represent the patient. Scatter entrance skin air kerma to the operator position (S-ESAK-O) was measured during fluoroscopy for all standard angulations and the S-ESAK-O per dose–area product (DAP) calculated, as applied to the phantom. Results: Measured mean (SD) left/right anterior oblique angulation ratios of S-ESAK-O without lead devices were 23.1 (10.1), and varied as a function of tube angulation, body height, and angle of incidence. S-ESAK-O/DAP decreased with incremental operator body height by 10 (3)% per 10 cm. A 1.0 mm lead glass shield reduced mean S-ESAK-O/DAP originating from coronary angiography from 1089 (764) to 54 (29) nSv/Gy × cm2. A 0.5 mm lead cap was effective in lowering measured levels to 1.8 (1.1) nSv/Gy × cm2. Both devices together enabled attenuation to 0.5 (0.1) nSv/Gy × cm2. The most advantageous line of vision for protection of the operator’s eyes was ⩾ 60° rightward. Conclusions: Use of 0.5 mm lead caps proved highly effective, attenuating S-ESAK-O to 2.7 (2.0) × 10−3 of baseline, and to 1.2 (1.4) × 10−3 of baseline where there was an additional 1.0 mm lead glass shield. These results could vary according to the x ray systems used, catheterisation protocols, and correct use of radiation protection devices. PMID:12975420

  13. Air lead exposures and blood lead levels within a large automobile manufacturing workforce, 1980-1985

    SciTech Connect

    Kononen, D.W.; Kintner, H.J.; Bivol, K.R. )

    1989-07-01

    Recent (1980-1985) trends in air lead (PbA) exposures and blood lead (PbB) levels experienced by approximately 10,000 workers employed in various stages of the automobile manufacturing process (i.e., auto assembly, lead-acid battery manufacture, foundry work, and other manufacturing-related operations) are described. Between 1980-1985, the mean PbB levels of assembly, battery, foundry, and other workers decreased by 28, 24, 3, and 27%, respectively, to 16.6, 23.6, 15.9, and 11.8 micrograms Pb/dl. Workers in the following job categories experienced the highest annual mean PbB levels: paste machine operators (battery plants), solder-grinders (assembly plants), and crane operators (foundries). During the same period, median 8-h Time Weighted Average PbA exposures (micrograms Pb/m3) in assembly plants, battery plants, and foundries decreased by 10, 12, and 20%, respectively, to 8.1, 13.6, and 10.9 micrograms/m3.

  14. Air lead exposures and blood lead levels within a large automobile manufacturing workforce, 1980-1985.

    PubMed

    Kononen, D W; Kintner, H J; Bivol, K R

    1989-01-01

    Recent (1980-1985) trends in air lead (PbA) exposures and blood lead (PbB) levels experienced by approximately 10,000 workers employed in various stages of the automobile manufacturing process (i.e., auto assembly, lead-acid battery manufacture, foundry work, and "other" manufacturing-related operations) are described. Between 1980-1985, the mean PbB levels of assembly, battery, foundry, and "other" workers decreased by 28, 24, 3, and 27%, respectively, to 16.6, 23.6, 15.9, and 11.8 micrograms Pb/dl. Workers in the following job categories experienced the highest annual mean PbB levels: paste machine operators (battery plants), solder-grinders (assembly plants), and crane operators (foundries). During the same period, median 8-h Time Weighted Average PbA exposures (micrograms Pb/m3) in assembly plants, battery plants, and foundries decreased by 10, 12, and 20%, respectively, to 8.1, 13.6, and 10.9 micrograms/m3. PMID:2782946

  15. Omaha childhood blood lead and environmental lead: a linear total exposure model

    SciTech Connect

    Angle, C.R.; Marcus, A.; Cheng, I.H.; McIntire, M.S.

    1984-01-01

    The majority of experimental and population studies of blood lead (PbB) and environmental lead, including the Omaha study, have utilized the Goldsmith-Hexter log-log or power function model. Comparison was made of the log-log model and a linear model of total exposure to describe the Omaha Study of 1074 PbBs from children ages 1-18 years as related to air (PbA), soil (PbS), and housedust (PbHD) lead. The data fit of the linear model was statistically equivalent to the power model and the predicted curves were biologically more plausible. The linear model avoids the mathematical limitations of the power model which predicts PbB zero at PbA zero. From the Omaha data, the model, ln PbB = ln (Bo + B1 PbA + B2 PbS + B3 PbHD) predicts that PbB increases 1.92 micrograms/dl as PbA increases 1.0 micrograms/cu. m. Since PbS and PbHD increase with PbA, however, the increases in total exposure predict a PbB increase of 4-5 micrograms/dl as PbA increases 1.0 micrograms/cu. m.

  16. Feather lead concentrations and207Pb/206Pb ratios reveal lead exposure history of California condors (Gymnogyps californianus)

    USGS Publications Warehouse

    Finkelstein, M.E.; George, D.; Scherbinski, S.; Gwiazda, R.; Johnson, M.; Burnett, J.; Brandt, J.; Lawrey, S.; Pessier, Allan P.; Clark, M.; Wynne, J.; Grantham, And J.; Smith, D.R.

    2010-01-01

    Lead poisoning is a primary factor impeding the survival and recovery of the critically endangered California Condor (Gymnogyps californianus). However, the frequency and magnitude of lead exposure in condors is not well-known in part because most blood lead monitoring occurs biannually, and biannual blood samples capture only ???10% of a bird's annual exposure history. We investigated the use of growing feathers from free-flying condors in California to establish a bird's lead exposure history. We show that lead concentration and stable lead isotopic composition analyses of sequential feather sections and concurrently collected blood samples provided a comprehensive history of lead exposure over the 2-4 month period of feather growth. Feather analyses identified exposure events not evident from blood monitoring efforts, and by fitting an empirically derived timeline to actively growing feathers, we were able to estimate the time frame for specific lead exposure events. Our results demonstrate the utility of using sequentially sampled feathers to reconstruct lead exposure history. Since exposure risk in individuals is one determinant ?? 2010 American Chemical Society.

  17. Influence of abatement of lead exposure in Croatia on blood lead and ALAD activity.

    PubMed

    Zorana, Kljaković-Gašpić; Alica, Pizent; Jasna, Jurasović

    2016-01-01

    We evaluated the effect of lead (Pb) abatement measures in Croatia on blood lead (BPb) concentrations, and delta-aminolevulinic acid dehydratase (ALAD) activity in blood, as a sensitive indicator of early Pb effect. Data on BPb and ALAD activity were obtained from 829 Croatian men (19-64 years of age), with no known occupational exposure to metals. Data obtained in 2008-2009, after the ban of leaded gasoline in Croatia in 2006, were compared with similar data collected in 1981 and 1989, when the concentration of Pb in gasoline was 0.6 g/L. Our results showed a highly significant (p < 0.001) decrease in median BPb from 114.5 (range, 46.0-275.0) μg/L in 1981/1989 to 30.3 (range, 3.2-140.8) μg/L in 2008-2009 and an increase in median ALAD activity from 49.8 (range, 24.9-79.4) EU in 1981/1989 to 60.9 (range, 35.8-84.0) EU in 2008-2009. Individual factors influencing BPb values were, in the order of decreasing importance, Pb in ambient air (APb), alcohol consumption, age, and smoking. Increased ALAD activity was significantly associated with the decrease of APb, alcohol consumption, and smoking. These results show that lead abatement measures had a positive impact on both BPb concentrations (73.5% decrease) and the activity of ALAD (22.1% increase) in general population. Our results contribute to growing evidence that ALAD activity may be used as one of the earliest and sensitive diagnostic biomarkers of low-level Pb exposure. PMID:26351197

  18. Beta-adrenergic receptor density and adenylate cyclase activity in lead-exposed rat brain after cessation of lead exposure.

    PubMed

    Chang, Huoy-Rou; Tsao, Der-An; Yu, Hsin-Su; Ho, Chi-Kung

    2005-01-01

    To understanding the reversible or irreversible harm to the beta-adrenergic system in the brain of lead-exposed rats, this study sets up an animal model to estimate the change in the sympathetic nervous system of brain after lead exposure was withdrawn. We address the following topics in this study: (a) the relationship between withdrawal time of lead exposure and brain beta-adrenergic receptor, blood lead level, and brain lead level in lead-exposed rats after lead exposure was stopped; and (b) the relationship between lead level and beta-adrenergic receptor and cyclic AMP (c-AMP) in brain. Wistar rats were chronically fed with 2% lead acetate and water for 2 months. Radioligand binding was assayed by a method that fulfilled strict criteria of beta-adrenergic receptor using the ligand [125I]iodocyanopindolol. The levels of lead were determined by electrothermal atomic absorption spectrometry. The c-AMP level was determined by radioimmunoassay. The results showed a close relationship between decreasing lead levels and increasing numbers of brain beta-adrenergic receptors and brain adenylate cyclase activity after lead exposure was withdrawn. The effect of lead exposure on the beta-adrenergic system of the brain is a partly reversible condition. PMID:15502967

  19. Analysis of the role of lead resistivity in specific absorption rate for deep brain stimulator leads at 3T MRI.

    PubMed

    Angelone, Leonardo M; Ahveninen, Jyrki; Belliveau, John W; Bonmassar, Giorgio

    2010-04-01

    Magnetic resonance imaging (MRI) on patients with implanted deep brain stimulators (DBSs) can be hazardous because of the antenna-effect of leads exposed to the incident radio-frequency field. This study evaluated electromagnetic field and specific absorption rate (SAR) changes as a function of lead resistivity on an anatomically precise head model in a 3T system. The anatomical accuracy of our head model allowed for detailed modeling of the path of DBS leads between epidermis and the outer table. Our electromagnetic finite difference time domain (FDTD) analysis showed significant changes of 1 g and 10 g averaged SAR for the range of lead resistivity modeled, including highly conductive leads up to highly resistive leads. Antenna performance and whole-head SAR were sensitive to the presence of the DBS leads only within 10%, while changes of over one order of magnitude were observed for the peak 10 g averaged SAR, suggesting that local SAR values should be considered in DBS guidelines. With rho(lead) = rho(copper) , and the MRI coil driven to produce a whole-head SAR without leads of 3.2 W/kg, the 1 g averaged SAR was 1080 W/kg and the 10 g averaged SAR 120 W/kg at the tip of the DBS lead. Conversely, in the control case without leads, the 1 g and 10 g averaged SAR were 0.5 W/kg and 0.6 W/kg, respectively, in the same location. The SAR at the tip of lead was similar with electrically homogeneous and electrically heterogeneous models. Our results show that computational models can support the development of novel lead technology, properly balancing the requirements of SAR deposition at the tip of the lead and power dissipation of the system battery. PMID:20335090

  20. Reducing lead in air and preventing childhood exposure near lead smelters: learning from the U.S. experience.

    PubMed

    Sullivan, Marianne

    2015-05-01

    Childhood lead exposure and poisoning near primary lead smelters continues in developed and developing countries. In the United States, the problem of lead poisoning in children caused by smelter emissions was first documented in the early 1970s. In 1978, Environmental Protection Agency set National Ambient Air Quality Standards for lead. Attainment of this lead standard in areas near operating lead smelters took twenty to thirty years. Childhood lead exposure and poisoning continued to occur after the lead National Ambient Air Quality Standards were set and before compliance was achieved. This article analyzes and discusses the factors that led to the eventual achievement of the 1978 lead National Ambient Air Quality Standards near primary smelters and the reduction of children's blood lead levels in surrounding communities. Factors such as federal and state regulation, monitoring of emissions, public health activities such as blood lead surveillance and health education, relocation of children, environmental group and community advocacy, and litigation all played a role. PMID:25815743

  1. Environmental Lead Exposure and Otoacoustic Emissions in Andean Children

    PubMed Central

    Buchanan, Leo H.; Counter, S. Allen; Ortega, Fernando

    2012-01-01

    Studies relating sensory hearing impairment to lead (Pb) exposure in children have presented inconsistent results. The objective of this study was to measure distortion product otoacoustic emissions (DPOAE), sounds emanating from the outer hair cells of the inner ear, in Pb-exposed children to determine the effects of Pb poisoning on the inner ear. DPOAE were recorded for 9 f2 frequencies from 1187 to 7625 Hz on 102 ears of 53 Pb-exposed children (aged 6–16 years) residing in Pb-contaminated environments in the Andes Mountains of Ecuador where Pb-glazing of ceramics is the primary livelihood. Blood lead (PbB) levels ranged from 4.2 to 94.3 µg/dl (mean: 37.7; SD: 25.7; median: 36.4). The median PbB level was significantly higher than the CDC and WHO’s 10 µg/dl action level. Spearman rho correlation analyses of the relation between PbB level and DPOAE amplitude, and between PbB level and DPOAE signal-to-noise ratio revealed no significant associations at any of the f2 frequencies tested. In addition, no significant correlation (Spearman rho) between PbB level and hearing sensitivity for 6 pure-tone test frequencies from 1000–8000 Hz was found. Although the study group was found to have abnormally elevated PbB levels, in contrast to some earlier reports, the results of the current study showed no consistent Pb-induced sensory effects on the cochlea of Pb-intoxicated children. PMID:21830857

  2. Identification of sources of lead exposure in French children by lead isotope analysis: a cross-sectional study

    PubMed Central

    2011-01-01

    Background The amount of lead in the environment has decreased significantly in recent years, and so did exposure. However, there is no known safe exposure level and, therefore, the exposure of children to lead, although low, remains a major public health issue. With the lower levels of exposure, it is becoming more difficult to identify lead sources and new approaches may be required for preventive action. This study assessed the usefulness of lead isotope ratios for identifying sources of lead using data from a nationwide sample of French children aged from six months to six years with blood lead levels ≥25 μg/L. Methods Blood samples were taken from 125 children, representing about 600,000 French children; environmental samples were taken from their homes and personal information was collected. Lead isotope ratios were determined using quadrupole ICP-MS (inductively coupled plasma - mass spectrometry) and the isotopic signatures of potential sources of exposure were matched with those of blood in order to identify the most likely sources. Results In addition to the interpretation of lead concentrations, lead isotope ratios were potentially of use for 57% of children aged from six months to six years with blood lead level ≥ 25 μg/L (7% of overall children in France, about 332,000 children), with at least one potential source of lead and sufficiently well discriminated lead isotope ratios. Lead isotope ratios revealed a single suspected source of exposure for 32% of the subjects and were able to eliminate at least one unlikely source of exposure for 30% of the children. Conclusions In France, lead isotope ratios could provide valuable additional information in about a third of routine environmental investigations. PMID:21871122

  3. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    SciTech Connect

    Simões, Maylla Ronacher; Aguado, Andrea; Fiorim, Jonaína; Silveira, Edna Aparecida; Azevedo, Bruna Fernandes; Toscano, Cindy Medice; Zhenyukh, Olha; Briones, Ana María; Alonso, María Jesús; Vassallo, Dalton Valentim; Salaices, Mercedes

    2015-03-01

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  4. Childhood lead exposure in an industrial town in China: coupling stable isotope ratios with bioaccessible lead.

    PubMed

    Li, Hong-Bo; Chen, Kai; Juhasz, Albert L; Huang, Lei; Ma, Lena Q

    2015-04-21

    Fingerprinting based on stable isotopes of lead (Pb) in blood and environmental media helps to identify Pb exposure pathways in children. However, previous studies used stable isotopes of total Pb in media. In this study, a wire rope production town in China (Zhuhang) was selected for investigating the effectiveness of using isotope ratios in bioaccessible Pb to identify childhood Pb exposure pathways. Blood Pb levels of 115 children in Zhuhang were 1.7-20.4 μg dL(-1), averaging 6.1 ± 3.2 μg dL(-1) (mean ± standard deviation), and were ∼1.6 times the national average in China (3.9 ± 1.8 μg dL(-1)). Among different environmental media (housedust, soil, PM10, vegetables, rice, and drinking water), housedust (695 ± 495 mg kg(-1)) and vegetables [0.36 ± 0.40 mg (kg of fresh weight)(-1)] contained elevated Pb concentrations. The isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) of total Pb were the highest in housedust (0.8587 ± 0.0039 and 2.1049 ± 0.0087) but lower than blood Pb ratios (0.8634 ± 0.0027 and 2.1244 ± 0.0061). When using bioaccessible Pb in housedust (0.8639 ± 0.0018 and 2.1171 ± 0.0036), the isotope ratios overlapped with blood Pb ratios, suggesting that incidental ingestion of housedust was the predominant contributor to children's blood Pb. Coupling the stable isotope technique with bioaccessible Pb is more reliable for identifying Pb exposure pathways than total Pb determinations. PMID:25803404

  5. Levels and source apportionment of children's lead exposure: could urinary lead be used to identify the levels and sources of children's lead pollution?

    PubMed

    Cao, Suzhen; Duan, Xiaoli; Zhao, Xiuge; Wang, Beibei; Ma, Jin; Fan, Delong; Sun, Chengye; He, Bin; Wei, Fusheng; Jiang, Guibin

    2015-04-01

    As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as (207)Pb/(206)Pb, (208)Pb/(206)Pb and (204)Pb/(206)Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis. PMID:25617855

  6. Impact of the California Lead Ammunition Ban on Reducing Lead Exposure in Golden Eagles and Turkey Vultures

    PubMed Central

    Kelly, Terra R.; Bloom, Peter H.; Torres, Steve G.; Hernandez, Yvette Z.; Poppenga, Robert H.; Boyce, Walter M.; Johnson, Christine K.

    2011-01-01

    Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites. PMID:21494329

  7. Lead exposure and growth in the early preschool child: A follow-up report from the Cincinnati Lead Study

    SciTech Connect

    Shukla, R.; Dietrich, K.N.; Bornschein, R.L.; Berger, O.; Hammond, P.B. )

    1991-11-01

    This report is a follow-up of an earlier study of the effects of low to moderate prenatal and postnatal lead exposure on children's growth in stature. Two hundred thirty-five subjects were assessed every 3 months for lead exposure (blood lead level) and stature (recumbent length) up to 33 months of age. Fetal lead exposure was indexed by maternal blood lead level during pregnancy. The adverse effects of lead on growth during the first year of life were reported previously. This analysis covers essentially the second and third years of life. The results indicate that mean blood lead level during this period was negatively associated with attained height at 33 months of age (P = .002). This association was, however, evidenced only among those children who had mean blood lead levels greater than the cohort median (greater than or equal to 10.77 micrograms/dL) during the 3- to 15-month interval. The results also suggest that the effect of lead exposure (both in utero as well as during the first year of life) are transient provided that subsequent exposure to lead is not excessive. It appears that maintaining an average blood lead level of 25 micrograms/dL or more during the second and third year of life was detrimental to the child's attained stature at 33 months of age. Approximately 15% of this cohort experienced these levels of lead exposure. Continued follow-up of this cohort will reveal whether these lead-related deficits persist and whether they continue to be dependent on the level of exposure in an earlier period.

  8. Prenatal Cigarette Exposure and Infant Learning Stimulation as Predictors of Cognitive Control in Childhood

    ERIC Educational Resources Information Center

    Mezzacappa, Enrico; Buckner, John C.; Earls, Felton

    2011-01-01

    Prenatal exposures to neurotoxins and postnatal parenting practices have been shown to independently predict variations in the cognitive development and emotional-behavioral well-being of infants and children. We examined the independent contributions of prenatal cigarette exposure and infant learning stimulation, as well as their…

  9. RELATIVE CONTRIBUTION OF LEAD FROM ANTHROPOGENIC SOURCES TO THE TOTAL HUMAN LEAD EXPOSURE IN THE U.S.

    EPA Science Inventory

    The paper evaluates human exposure to lead at a baseline level for persons living in non-urban communities away from stationary or mobile sources of lead, eating typical diets, and engaging in no lead-related occupational or avocational activities. Relative contributions of atmos...

  10. Childhood Exposure to Lead: A Common Cause of School Failure.

    ERIC Educational Resources Information Center

    Needleman, Herbert L.

    1992-01-01

    According to the U.S. Public Health Service, lead poisoning remains the most common and societally devastating environmental disease of young children. About 16 percent all American children have blood lead levels in the neurotoxic range. Being poor dramatically increases this risk. The lead industry has long camouflaged lead's toxicity.…

  11. Technical performance of percutaneous leads for spinal cord stimulation: a modeling study.

    PubMed

    Manola, Ljubomir; Holsheimer, Jan; Veltink, Peter

    2005-04-01

    Objective  To compare the technical performance of different percutaneous lead types for spinal cord stimulation. Methods  Using the ut-scs software (University of Twente's spinal cord stimulation), lead models having similar characteristics such as the 3487A PISCES-Quad (PQ), 3887 PISCES-Quad Compact (PC), 3888 PISCES-Quad Plus (PP) (Medtronic Inc., Minneapolis, MN), and the AB SC2108 (AB) (Advanced Bionics Corp., Valencia, CA) were simulated in monopolar and tripolar (guarded cathode) combinations on a single lead, placed just outside the dorsal dura mater and both centered on the spinal cord midline, and at 1 mm lateral. The influence of displacing a lead dorsally in the epidural fat was examined as well. Finally, dual leads both aligned and offset were modeled. Several parameters were calculated to allow a quantitative comparison of the performances. Results  When programmed as a guarded cathode, the AB lead recruits nerve fibers in an ~25% larger dorsal column area than the PQ. However, the AB has an ~160% higher energy consumption. The performance of the PC is between the AB and PQ, whereas the PP is suitable only for dorsal root stimulation. Displacing a single lead off midline or dorsally decreases its ability to recruit fibers in the dorsal columns. Similarly, dual lead combinations are less capable when compared to single lead centered on the spinal cord midline just outside the dura mater. Conclusions  Complex pain syndromes are treated best with lead having a small contact spacing, being programmed as a tripole (guarded cathode) and centered on the spinal cord midline just outside the dura mater. This is because dorsal column fiber recruitment is more extensive than with any other combinations, including dual leads. Improved recruitment of dorsal column fibers is accompanied by increased energy consumption. PMID:22151437

  12. Neuromuscular electrical stimulation leads to physiological gains enhancing postural balance in the pre-frail elderly

    PubMed Central

    Mignardot, Jean-Baptiste; Deschamps, Thibault; Le Goff, Camille G; Roumier, François-Xavier; Duclay, Julien; Martin, Alain; Sixt, Marc; Pousson, Michel; Cornu, Christophe

    2015-01-01

    Physiological aging leads to a progressive weakening of muscles and tendons, thereby disturbing the ability to control postural balance and consequently increasing exposure to the risks of falls. Here, we introduce a simple and easy-to-use neuromuscular electrical stimulation (NMES) training paradigm designed to alleviate the postural control deficit in the elderly, the first hallmarks of which present as functional impairment. Nine pre-frail older women living in a long-term care facility performed 4 weeks of NMES training on their plantarflexor muscles, and seven nontrained, non-frail older women living at home participated in this study as controls. Participants were asked to perform maximal voluntary contractions (MVC) during isometric plantarflexion in a lying position. Musculo-tendinous (MT) stiffness was assessed before and after the NMES training by measuring the displacement of the MT junction and related tendon force during MVC. In a standing position, the limit of stability (LoS) performance was determined through the maximal forward displacement of the center of foot pressure, and related postural sway parameters were computed around the LoS time gap, a high force requiring task. The NMES training induced an increase in MVC, MT stiffness, and LoS. It significantly changed the dynamics of postural balance as a function of the tendon property changes. The study outcomes, together with a multivariate analysis of investigated variables, highlighted the benefits of NMES as a potential tool in combating neuromuscular weakening in the elderly. The presented training-based strategy is valuable in alleviating some of the adverse functional consequences of aging by directly acting on intrinsic biomechanical and muscular properties whose improvements are immediately transferable into a functional context. PMID:26229006

  13. Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District

    USGS Publications Warehouse

    Beyer, W. Nelson; Franson, J. Christian; French, John B.; May, Thomas; Rattner, Barnett A.; Shearn-Bochsler, Valerie I.; Warner, Sarah E.; Weber, John; Mosby, David

    2013-01-01

    Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000–3,200 mg Pb/kg. Analyses of earthworms [33–4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11–3.0 (reference) and 1.3–30 (contaminated) and American robin (Turdus migratorius) = 0.43–8.5 (reference) and 7.6–72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32 %) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9 %) with systemic toxic effects, and 4 (12 %) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58–82 % in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

  14. Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District.

    PubMed

    Beyer, W Nelson; Franson, J Christian; French, John B; May, Thomas; Rattner, Barnett A; Shearn-Bochsler, Valerie I; Warner, Sarah E; Weber, John; Mosby, David

    2013-10-01

    Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000-3,200 mg Pb/kg. Analyses of earthworms [33-4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11-3.0 (reference) and 1.3-30 (contaminated) and American robin (Turdus migratorius) = 0.43-8.5 (reference) and 7.6-72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32%) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9%) with systemic toxic effects, and 4 (12%) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58-82% in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb. PMID:23771631

  15. EVIDENCE FOR EFFECTS OF CHRONIC LEAD EXPOSURE ON BLOOD PRESSURE IN EXPERIMENTAL ANIMALS: AN OVERVIEW

    EPA Science Inventory

    Information obtained in a number of experimental studies conducted over the last forty years on the effects of lead on blood pressure is reviewed. Differences in animal species, age at beginning of exposure, level of lead exposure, indices of lead burden, and blood pressure effec...

  16. A Simple Technique for Surgical Placement of Occipital Nerve Stimulators without Anchoring the Lead.

    PubMed

    Plazier, Mark; Camp, Tim Van; Mevnosky, Tomas; Ost, Jan; De Ridder, Dirk; Vanneste, Sven

    2016-09-01

    Introduction Greater occipital nerve stimulation is applied in the treatment of occipital neuralgia, headache, and fibromyalgia. Multiple techniques have been described along with their subsequent complications. The most frequent complications are related to lead migration, infection, and undesired stimulation effects. Revision surgery occurs in up to 60% of the cases. Patients and Methods A total of 92 implantations, 51 trials (6-10 weeks), and 41 permanent implantations (follow-up: 36-72 months) were performed in a single center using a simple technique without an anchoring device. The electrode is tunneled at a 45-degree angle to prevent migration. Complications and additional surgeries were recorded during the follow-up period. Results All patients had bilateral greater occipital nerve stimulation. A total of 16 complications (17.4%) occurred. Seven patients (7.6%) underwent additional surgery. The major complication was infection; lead migration made up only 3.3% of the complications. Conclusions We present a simple technique without the use of an anchoring device that is feasible in achieving bilateral occipital nerve stimulation and decreases the complications, especially lead migration. PMID:26444964

  17. Lead exposure in Laysan albatross adults and chicks in Hawaii: prevalence, risk factors, and biochemical effects.

    USGS Publications Warehouse

    Work, T.M.; Smith, M.R.

    1996-01-01

    Prevalence of lead exposure and elevated tissue lead was determined in Laysan albatross (Diomedea immutabilis) in Hawaii. The relationship between lead exposure and proximity to buildings, between elevated blood lead and droopwing status, and elevated liver lead and presence of lead-containing paint chips in the proventriculus in albatross chicks was also examined. Finally, the effects of lead on the enzyme δ-amino-levulinic acid dehydratase (ALAD) was determined. There was a significant association between lead exposure or elevated tissue lead and proximity to buildings in albatross chicks and presence of lead paint chips in the proventriculus and elevated liver lead in carcasses. Although there was a significant association between elevated blood lead and droopwing chicks, there were notable exceptions. Prevalence of elevated tissue lead in albatross chicks was highest on Sand Island Midway and much less so on Kauai and virtually nonexistent in other areas. Prevalence of lead exposure decreased as numbers of buildings to which chicks were exposed on a given island decreased. Laysan albatross adults had minimal to no lead exposure. There was a significant negative correlation between blood lead concentration and ALAD activity in chicks. Based on ALAD activity, 0.03-0.05 μg/ml was the no effect range for blood lead in albatross chicks.

  18. Effects of lead exposure before pregnancy and dietary calcium during pregnancy on fetal development and lead accumulation.

    PubMed Central

    Han, S; Pfizenmaier, D H; Garcia, E; Eguez, M L; Ling, M; Kemp, F W; Bogden, J D

    2000-01-01

    Millions of women of child-bearing age have substantial bone lead stores due to lead exposure as children. Dietary calcium ingested simultaneously with lead exposure can reduce lead absorption and accumulation. However, the effects of dietary calcium on previously accumulated maternal lead stores and transfer to the fetus have not been investigated. We studied the effects of lead exposure of female rats at an early age on fetal development during a subsequent pregnancy. We gave 5-week-old female Sprague-Dawley rats lead as the acetate in their drinking water for 5 weeks; controls received equimolar sodium acetate. This was followed by a 1-month period without lead exposure before mating. We randomly assigned pregnant rats (n = 39) to diets with a deficient (0.1%) or normal (0.5%) calcium content during pregnancy. A total of 345 pups were delivered alive. Lead-exposed dams and their pups had significantly higher blood lead concentrations than controls, but the concentrations were in the range of those found in many pregnant women. Pups born to dams fed the calcium-deficient diet during pregnancy had higher blood and organ lead concentrations than pups born to dams fed the 0. 5% calcium diet. Pups born to lead-exposed dams had significantly (p<0.0001) lower mean birth weights and birth lengths than controls. There were significant inverse univariate associations between dam or pup organ lead concentrations and birth weight or length. The 0.5% calcium diet did not increase in utero growth. Stepwise regression analysis demonstrated that greater litter size and female sex were significantly associated with reduced pup birth weight and length. However, lead exposure that ended well before pregnancy was significantly (p<0.0001) associated with reduced birth weight and length, even after litter size, pup sex, and dam weight gain during pregnancy were included in the regression analysis. The data demonstrate that an increase in dietary calcium during pregnancy can reduce

  19. Effect of occupational lead exposure on lymphocyte enzymes involved in heme biosynthesis

    SciTech Connect

    Rossi, E.; Costin, K.A.; Garcia-Webb, P. )

    1990-11-01

    Lead exposure is a well-known cause of increases in urinary coproporphyrin and erythrocyte zinc-protoporphyrin, so these compounds are often used to monitor occupational lead exposure. The increased concentrations are usually assumed to result from lead inhibition of two of the mitochondrial enzymes of heme biosynthesis, coproporphyrinogen oxidase and ferrochelatase. We studied 88 subjects in whom the degree of occupational lead exposure was established by measuring erythrocyte lead and protoporphyrin. Assay of lymphocyte coproporphyrinogen oxidase and ferrochelatase activities showed that these enzymes were unaffected by lead exposure, as was a related enzyme, lymphocyte NADH-ferricyanide reductase. We propose alternative explanations for the increased concentrations of coproporphyrin and zinc-protoporphyrin seen in lead exposure.

  20. Lead exposure in Latin America and the Caribbean. Lead Research Group of the Pan-American Health Organization.

    PubMed Central

    Romieu, I; Lacasana, M; McConnell, R

    1997-01-01

    As a result of the rapid industrialization of Latin America and the Caribbean during the second half of this century, exposure to lead has become an increasingly important problem. To obtain an estimate of the magnitude of lead exposure in the region, we carried out a survey and a literature search on potential sources of lead exposure and on blood lead concentrations. Sixteen out of 18 Latin American and 2 out of 10 Caribbean countries responded to the survey. Lead in gasoline remains a major problem, although the lead content has decreased in many countries in the last few years. The impact of leaded fuel is more important in urban settings, given their high vehicular density. Seventy-five percent of the population of the region lives in urban areas, and children younger than 15 years of age, the most susceptible group, comprise 30% of the population. Other sources of lead exposure identified in the region included industrial emissions, battery recycling, paint and varnishes, and contaminated food and water. Lead is recognized as a priority problem by national authorities in 72% of the countries that responded to the survey, and in 50% of the countries some legislation exists to regulate the lead content in certain products. However, compliance is low. There is an urgent need for a broad-based coalition between policy makers, industry, workers, unions, health care providers, and the community to take actions to reduce environmental and occupational lead exposures in all the Latin American and Caribbean countries. Images Figure 1. Figure 2. PMID:9189704

  1. Toxic lead exposure in the urban rock dove

    SciTech Connect

    DeMent, S.H.; Chisolm, J.J. Jr.; Eckhaus, M.A.; Strandberg, J.D.

    1987-04-01

    Thirteen adult urban rock doves (Columba livia), 12 captured alive and one found dead, were studied from the Baltimore zoo. The mean concentration of lead in the blood for the 12 live birds was 184.5 +/- 531.2 (range 10.5-1,870 micrograms/dl). Three of the 13 birds with high measured blood and tissue lead concentrations were found at necropsy with lead shot pellets in their gizzards. Correlations were not found between concentrations of lead in the blood and body weight or hematocrit. Conversely, high correlations were noted between concentrations of lead in the blood and measured liver and kidney concentrations (r = 0.946, P less than 0.01; r = 0.993, P less than 0.01, respectively). Numbers of intranuclear acid-fast inclusions per 10 consecutive fields (100x oil immersion lens) correlated well with measured kidney lead concentrations (r = 0.990, P less than 0.001).

  2. Investigation into Deep Brain Stimulation Lead Designs: A Patient-Specific Simulation Study.

    PubMed

    Alonso, Fabiola; Latorre, Malcolm A; Göransson, Nathanael; Zsigmond, Peter; Wårdell, Karin

    2016-01-01

    New deep brain stimulation (DBS) electrode designs offer operation in voltage and current mode and capability to steer the electric field (EF). The aim of the study was to compare the EF distributions of four DBS leads at equivalent amplitudes (3 V and 3.4 mA). Finite element method (FEM) simulations (n = 38) around cylindrical contacts (leads 3389, 6148) or equivalent contact configurations (leads 6180, SureStim1) were performed using homogeneous and patient-specific (heterogeneous) brain tissue models. Steering effects of 6180 and SureStim1 were compared with symmetric stimulation fields. To make relative comparisons between simulations, an EF isolevel of 0.2 V/mm was chosen based on neuron model simulations (n = 832) applied before EF visualization and comparisons. The simulations show that the EF distribution is largely influenced by the heterogeneity of the tissue, and the operating mode. Equivalent contact configurations result in similar EF distributions. In steering configurations, larger EF volumes were achieved in current mode using equivalent amplitudes. The methodology was demonstrated in a patient-specific simulation around the zona incerta and a "virtual" ventral intermediate nucleus target. In conclusion, lead design differences are enhanced when using patient-specific tissue models and current stimulation mode. PMID:27618109

  3. Childhood Lead Exposure After the Phaseout of Leaded Gasoline: An Ecological Study of School-Age Children in Kampala, Uganda

    PubMed Central

    Graber, Lauren K.; Asher, Daniel; Anandaraja, Natasha; Bopp, Richard F.; Merrill, Karen; Cullen, Mark R.; Luboga, Samuel; Trasande, Leonardo

    2010-01-01

    Background Tetraethyl lead was phased out of gasoline in Uganda in 2005. Recent mitigation of an important source of lead exposure suggests examination and re-evaluation of the prevalence of childhood lead poisoning in this country. Ongoing concerns persist about exposure from the Kiteezi landfill in Kampala, the country’s capital. Objectives We determined blood lead distributions among Kampala schoolchildren and identified risk factors for elevated blood lead levels (EBLLs; ≥ 10 μg/dL). Analytical approach Using a stratified, cross-sectional design, we obtained blood samples, questionnaire data, and soil and dust samples from the homes and schools of 163 4- to 8-year-old children representing communities with different risks of exposure. Results The mean blood lead level (BLL) was 7.15 μg/dL; 20.5% of the children were found to have EBLL. Multivariable analysis found participants whose families owned fewer household items, ate canned food, or used the community water supply as their primary water source to have higher BLLs and likelihood of EBLLs. Distance < 0.5 mi from the landfill was the factor most strongly associated with increments in BLL (5.51 μg/dL, p < 0.0001) and likelihood of EBLL (OR = 4.71, p = 0.0093). Dust/soil lead was not significantly predictive of BLL/EBLL. Conclusions Lead poisoning remains highly prevalent among school-age children in Kampala. Confirmatory studies are needed, but further efforts are indicated to limit lead exposure from the landfill, whether through water contamination or through another mechanism. Although African nations are to be lauded for the removal of lead from gasoline, this study serves as a reminder that other sources of exposure to this potent neurotoxicant merit ongoing attention. PMID:20194080

  4. SKELETAL EFFECTS OF DEVELOPMENTAL LEAD EXPOSURE IN RATS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To identify possible direct and indirect mechanisms underlying the effects of lead on skeletal growth, 3 studies were conducted. In the first study, 1 male and 1 female pup/litter (n = 5 litters), were exposed ad libitum to 0, 825, or 2475 ppm lead acetate in the drinking water from gestational day...

  5. Current issues in the epidemiology and toxicology of occupational exposure to lead

    SciTech Connect

    Landrigan, P.J. )

    1990-11-01

    Occupational exposure to lead is widespread in the US. Clinically evident lead poisoning as well as subclinical toxicity occur in populations with occupational lead exposure. The focus of current research on lead toxicity in industrial populations is in the definition of dose-response relationships, particularly at low levels of exposure. Major interest surrounds the development of biochemical and physiologic markers of subclinical toxicity. Need exists to better delineate the toxicity of lead on the peripheral and central nervous system, the kidneys, the cardiovascular system, and the reproductive organs using newly developed markers. To obtain more accurate information on cumulative individual exposure to lead, future research on lead toxicity will increasingly use x-ray fluorescence analysis for determination of the lead content in bone.

  6. Lead exposure: Occupational health hazards. (Latest citations from the Life Sciences Collection database). Published Search

    SciTech Connect

    Not Available

    1993-02-01

    The bibliography contains citations concerning occupational exposure to lead and its health consequences. Foundry workers, orchard workers, mechanics, industrial workers, and lumbermen are among the workers studied. The citations explore chronic effects of lead exposure on adults and present assay methods for determining blood lead levels. Mortality studies of workers exposed to lead and other synergistic toxins such as cadmium and nickel are also cited. Lead exposure in infants and children is discussed in a separate bibliography. (Contains a minimum of 199 citations and includes a subject term index and title list.)

  7. Inequitable Chronic Lead Exposure: A Dual Legacy of Social and Environmental Injustice.

    PubMed

    Leech, Tamara G J; Adams, Elizabeth A; Weathers, Tess D; Staten, Lisa K; Filippelli, Gabriel M

    2016-01-01

    Both historic and contemporary factors contribute to the current unequal distribution of lead in urban environments and the disproportionate impact lead exposure has on the health and well-being of low-income minority communities. We consider the enduring impact of lead through the lens of environmental justice, taking into account well-documented geographic concentrations of lead, legacy sources that produce chronic exposures, and intergenerational transfers of risk. We discuss the most promising type of public health action to address inequitable lead exposure and uptake: primordial prevention efforts that address the most fundamental causes of diseases by intervening in structural and systemic inequalities. PMID:27214670

  8. Uses and limits of empirical data in measuring and modeling human lead exposure.

    PubMed Central

    Mushak, P

    1998-01-01

    This paper examines the uses and limits of empirical data in evaluating measurement and modeling approaches to human lead exposure. Empirical data from experiment or observation or both have been used in studies of lead exposure. For example, experimental studies have elucidated and quantified physiologic or biokinetic parameters of lead exposure under controlled conditions. Observation, i.e., epidemiology, has been widely applied to study population exposures to lead. There is growing interest in the use of lead exposure prediction models and their evaluation before use in risk assessment. Empirical studies of lead exposure must be fully understood, especially their limits, before they are applied as "standards" or reference information for evaluation of exposure models, especially the U.S. Environmental Protection Agency's lead biokinetic model that is a focus of this article. Empirical and modeled datasets for lead exposure may not agree due to a) problems with the observational data or b) problems with the model; caution should be exercised before either a model or observational data are rejected. There are at least three sources of discordance in cases where there is lack of agreement: a) empirical data are accurate but the model is flawed; b) the model is valid but reference empirical data are inaccurate; or c) neither empirical data nor model is accurate, and each is inaccurate in different ways. This paper evaluates some of the critical empirical input to biokinetic models, especially lead bioavailability. Images Figure 3 PMID:9860906

  9. Prenatal lead exposure and relationship with maternal exposure determinants in a public maternity hospital of La Plata, Argentina.

    PubMed

    Martins, Enrique; Varea, Ana; Apezteguía, María; González, Horacio F; Girardelli, Ana; Caro, Laura Sanchez; Lobisuto, Mario; Delgado, Griselda; Disalvo, Liliana

    2014-03-01

    Prenatal lead exposure is a health hazard that may cause cognitive development impairments and other adverse effects in children. We conducted a cross sectional study analyzing cord blood lead levels (CBLL) of newborns and their relationship with maternal determinants of lead exposure. Mothers answered a questionnaire about socio-demographic, lifestyle habits and environmental characteristics. We used Mann-Whitney's test to compare CBLL geometrical means (GM) corresponding to the presence or absence of each lead exposure determinant, and Chi square test to study the relationship between CBLL and maternal lead exposure determinants. A total of 159 newborns participated in the study. CBLL GM was 2.1 μg/dL; and 25% of the participants had a measurable CBLL (LOQ=3.3 μg/dl). Although the participants had several determinants of lead exposure, we only found a significant relationship with inside household determinants, such as presence of lead piping (p=0.026), unplastered walls (p=0.046) and peeling paint (p=0.048). Our results show that CBLL GM was similar to that reported in several studies conducted around the world. However, 25% of the participants might have some degree of risk for lead poisoning. PMID:24361446

  10. Childhood lead exposure in France: benefit estimation and partial cost-benefit analysis of lead hazard control

    PubMed Central

    2011-01-01

    Background Lead exposure remains a public health concern due to its serious adverse effects, such as cognitive and behavioral impairment: children younger than six years of age being the most vulnerable population. In Europe, the lead-related economic impacts have not been examined in detail. We estimate the annual costs in France due to childhood exposure and, through a cost benefit analysis (CBA), aim to assess the expected social and economic benefits of exposure abatement. Methods Monetary benefits were assessed in terms of avoided national costs. We used results from a 2008 survey on blood-lead (B-Pb) concentrations in French children aged one to six years old. Given the absence of a threshold concentration being established, we performed a sensitivity analysis assuming different hypothetical threshold values for toxicity above 15 μg/L, 24 μg/L and 100 μg/L. Adverse health outcomes of lead exposure were translated into social burden and economic costs based on literature data from literature. Direct health benefits, social benefits and intangible avoided costs were included. Costs of pollutant exposure control were partially estimated in regard to homes lead-based paint decontamination, investments aiming at reducing industrial lead emissions and removal of all lead drinking water pipes. Results The following overall annual benefits for the three hypothetical thresholds values in 2008 are: €22.72 billion, €10.72 billion and €0.44 billion, respectively. Costs from abatement ranged from €0.9 billion to 2.95 billion/year. Finally, from a partial CBA of lead control in soils and dust the estimates of total net benefits were € 3.78 billion, € 1.88 billion and €0.25 billion respectively for the three hypothesized B-Pb effect values. Conclusions Prevention of childhood lead exposure has a high social benefit, due to reduction of B-Pb concentrations to levels below 15 μg/L or 24 μg/L, respectively. Reducing only exposures above 100 μg/L B-Pb has

  11. Tooth analyses of sources and intensity of lead exposure in children.

    PubMed Central

    Gulson, B L

    1996-01-01

    The sources and intensity of lead exposure in utero and in early childhood were determined using stable lead isotopic ratios and lead concentrations of incisal and cervical sections of deciduous teeth from 30 exposed and nonexposed children from the Broken Hill lead mining community in Australia. Incisal sections, consisting mostly of enamel, generally have low amounts of lead and isotopic compositions consistent with those expected in the mother during pregnancy. Cervical sections, consisting mostly of dentine with secondary dentine removed by resorption and reaming, generally have higher amounts of lead than the enamel and isotopic compositions consistent with the source of postnatal exposure. There are statistically significant differences in lead concentrations between incisal and cervical sections, representing within-tooth variation, for children with low and high lead exposure (p = 0.0007, 2 x 10(-6), respectively) and for those who have ingested leaded paint (p = 0.009). Statistically significant differences between incisal and cervical sections in these three exposure groups are also exhibited by the three sets of lead isotope ratios (e.g., p = 0.001 for 206Pb/204Pb ratio in the low exposure group). There are statistically significant differences between the low and high lead exposure groups for lead concentrations and isotopic ratios in incisal (p = 0.005 for lead concentration and 6 x 10(-6) for 206Pb/204Pb ratio) and cervical sections (p = 5 x 10(-5) for lead concentration and 6 x 10(-6) for 206Pb/204Pb ratio). The dentine results reflect an increased exposure to lead from the lead-zinc-silver mineral deposit (orebody lead) during early childhood, probably associated with hand-to-mouth activity. Leaded paint was identified as the source of elevated tooth lead in at least two cases. Increased exposure to lead from orebody and paint sources in utero was implicated in two cases, but there was no indication of previous exposure from the mothers' current

  12. Can realtor education reduce lead exposures for vulnerable populations?

    PubMed

    Phoenix, Janet A; Green, Rodney D; Thompson, Aisha M

    2013-01-01

    Lead is known for its devastating effects on people, particularly children under the age of six. Disturbed lead paint in homes is the most common source of lead poisoning of children. Preventive approaches including consumer education on the demand side of the housing market (purchasers and renters of housing units) and disclosure regulations on supply side of the housing market (landlords, homeowners, developers, and licensed realtors) have had mixed outcomes. The study described in this article considered whether a novel supply-side intervention that educates licensed real estate agents about the specific dangers of lead poisoning would result in better knowledge of lead hazards and improved behavior with respect to the information they convey to potential home buyers. Ninety-one licensed realtors were trained for four hours on lead hazards and their health impacts. Pre- and postsurveys and a six-month follow-up interview were conducted to assess the impact of the intervention on their knowledge and self-reported behaviors with clients. The findings suggest that supply-side education could have a salutary impact on realtor knowledge and behavior. PMID:23947286

  13. Correlation between biochemical indicators of lead exposure and semen quality in a lead-poisoned firearms instructor

    SciTech Connect

    Fisher-Fischbein, J.; Fischbein, A.; Melnick, H.D.; Bardin, C.W.

    1987-02-13

    Lead poisoning is a disease of great public health concern, particularly because of the hazards that lead can pose to children as a result of ingestion of lead-based paint and perhaps as a consequence of the effects of lead pollution of the ambient air. However, lead poisoning is also a common occupational disease among adults. Persons who work as instructors at indoor firing ranges are likewise at high risk for occupational lead poisoning. The typical biochemical features of lead poisoning include inhibition of heme synthesis manifested by elevated levels of erythrocyte protoporphyrin and decreased activity of sigma-aminolevulinic acid dehydratase. Reproductive effects of lead have been reported in both men and women, but these effects rarely present themselves as practical clinical problems in occupational medicine practice. The current Department of Labor standard for occupational exposure to inorganic lead has been promulgated with special emphasis on the protection of the worker from damage to the reproductive system. The authors had the opportunity of measuring biologic indicators of lead exposure and of assessing semen quality in a firearms instructor with lead poisoning and infertility, who was treated and who fathered a child. They report herein the results of these longitudinal observations.

  14. Prenatal cigarette exposure and infant learning stimulation as predictors of cognitive control in childhood.

    PubMed

    Mezzacappa, Enrico; Buckner, John C; Earls, Felton

    2011-07-01

    Prenatal exposures to neurotoxins and postnatal parenting practices have been shown to independently predict variations in the cognitive development and emotional-behavioral well-being of infants and children. We examined the independent contributions of prenatal cigarette exposure and infant learning stimulation, as well as their inter-relationships in predicting variations in the proficiency of executive attention, a core element of cognitive control and self-regulation. Participants were an ethnic-racially, socio-economically diverse sample of 249 children followed from birth in the Project on Human Development in Chicago Neighborhoods. We obtained histories of prenatal exposure to alcohol, cigarettes, and other drugs, and we assessed socio-economic status and learning stimulation during a home visit when the participants were infants. In childhood we utilized the Attention Networks Test to assess the proficiency of executive attention during two home visits, one year apart. Accounting for age, SES, prenatal alcohol exposure, and baseline performance, we found that prenatal cigarette exposure impaired the speed of executive attention. Infant learning stimulation mitigated these effects, and predicted better accuracy of executive attention as well, suggestive of both protective and health promoting effects. Effect sizes for these relations, whether examined independently or by their inter-relationships, were comparable to if not greater in magnitude than the effects of age on speed and accuracy, highlighting the importance of these very early experiences in shaping the proficiency of self-regulation. Since executive attention is central to cognitive control and self-regulation, previously described relations between prenatal cigarette exposure, parenting practices, and some forms of childhood psychopathology may be contingent on how early learning stimulation contributes to the proficiency of executive attention through direct and indirect effects. Furthermore

  15. Implications of new data on lead toxicity for managing and preventing exposure

    SciTech Connect

    Silbergeld, E.K. )

    1990-11-01

    Recent advances in research on low-level lead poisoning point to the need to increase efforts to prevent exposure. Current biomedical consensus accepts that blood lead levels as low as 5 to 15 mcg/dL are risky to fetuses, young children, and adults. Lead at low dose is associated with increased blood pressure in adults, and chronic exposure has been associated in cohort studies with kidney disease and cancer. Data on lead toxicokinetics also points to the hazards of low-level, chronic exposure, since the lead that is accumulated over time in bone can be released at a relatively rapid rate during pregnancy and menopause. Sources that contribute to current lead exposure of the general population include unabated lead-based paint and contaminated soils, as well as lower level but pervasive sources in drinking water, food, and consumer products.

  16. Implications of new data on lead toxicity for managing and preventing exposure.

    PubMed Central

    Silbergeld, E K

    1990-01-01

    Recent advances in research on low-level lead poisoning point to the need to increase efforts to prevent exposure. Current biomedical consensus accepts that blood lead levels as low as 5 to 15 mcg/dL are risky to fetuses, young children, and adults. Lead at low dose is associated with increased blood pressure in adults, and chronic exposure has been associated in cohort studies with kidney disease and cancer. Data on lead toxicokinetics also points to the hazards of low-level, chronic exposure, since the lead that is accumulated over time in bone can be released at a relatively rapid rate during pregnancy and menopause. Sources that contribute to current lead exposure of the general population include unabated lead-based paint and contaminated soils, as well as lower level but pervasive sources in drinking water, food, and consumer products. PMID:2088754

  17. Evaluation of preventive and control measures for lead exposure in a South African lead-acid battery recycling smelter.

    PubMed

    Dyosi, Sindiswa

    2007-10-01

    In South Africa, new lead regulations released in February 2002 served as motivation for a cross-sectional study investigating the effectiveness of preventive and control measures implemented in a lead smelter that recycles lead-acid batteries. Twenty-two workers were observed and interviewed. Structured questionnaires were used to gather workers' personal information, perception about their work environment, health risks, and work practices. Retrospective data from air monitoring and medical surveillance programs were obtained from the plant's records. The smelter implemented a number of control measures for lead exposure, including engineering controls, administrative controls, and, as a last resort, personal protective equipment. Engineering controls were rated the best control measure and included local exhaust ventilation systems and wet methods. Positive pressure systems were used in the offices and laboratory. The local exhaust ventilation system was rated the best engineering control measure. Although control measures were used, areas such as smelting and refinery had average lead in air levels above 0.15 mg/m(3), the occupational exposure limit for lead. This was a concern especially with regard to the smelting area because those workers had the second highest mean blood lead levels; workers in the battery breaking area had the highest. Regular use of personal protective equipment by some workers in the "lead exposure zones" was not observed. Although the mean blood lead levels had been below 40 micro g/dL for more than 90% of the workers since 2001, more than 70% of workers reported concerns about their health while working in the smelter. Even though control measures were implemented, they were not adequate because in some areas lead in air exceeded the occupational exposure limit. Therefore, improvement of existing measures and regular monitoring of personal protective equipment use were included in the recommendations given to the smelter. PMID

  18. MC-LR Exposure Leads to Subfertility of Female Mice and Induces Oxidative Stress in Granulosa Cells

    PubMed Central

    Wu, Jiang; Yuan, Mingming; Song, Yuefeng; Sun, Feng; Han, Xiaodong

    2015-01-01

    Health risk of human exposure to microcystin-leucine arginine (MC-LR) has aroused more and more attention over the past few decades. In the present study, MC-LR was orally administered to female mice at 0, 1, 10 and 40 μg/L for three and six months. We found that chronic exposure to MC-LR at environmental levels could stimulate follicle atresia and lead to decreased developmental follicles, accompanied by a reduction of gonadosomatic index (GSI). In line with the irregular gonadal hormone level and estrus cycles, subfertility of female mice was also confirmed by analyzing numbers of litters and pups. The in vitro study suggested that granulosa cells could uptake MC-LR and should be the target of the toxicant. Oxidative stress in granulose cells induced by MC-LR promoted follicle atresia and eventually leads to female subfertility. PMID:26633508

  19. DEVELOPMENTAL EXPOSURE TO A THYROID DISRUPTING CHEMICAL STIMULATES PHAGOCYTOSIS IN JUVENILE SPRAGUE-DAWLEY RATS

    EPA Science Inventory

    Developmental Exposure to a Thyroid Disrupting Chemical Stimulates Phagocytosis in Juvenile Sprague-Dawley Rats.
    AA Rooney1, R Matulka2, and R Luebke3. 1NCSU/US EPA CVM, Department of Anatomy, Physiological Sciences and Radiology, Raleigh, NC;2UNC Department of Toxicology, Cha...

  20. Lead exposure in American black ducks after implementation of non-toxic shot

    USGS Publications Warehouse

    Samuel, M.D.; Bowers, E. Frank

    2000-01-01

    Lead poisoning from the ingestion of spent shotgun pellets has been recognized as an important disease of North American waterfowl since Bellrose's (1959) research >40 years ago. Nation-wide regulations banning the use of lead shot for waterfowl hunting were established in 1991. We compared the prevalence of lead exposure in American black ducks (Anas rubripes) wintering on 2 areas in Tennessee before (1986-88) and after the ban (1997-99) to assess the effect of the ban on lead shot on this species. Prevalence of elevated blood lead in black ducks declined by 44% from before (11.7% prevalence) to after (6.5% prevalence) the implementation of non-toxic shot. The reduction in lead exposure was pronounced in adult black ducks (from 14.3% to 5.3%). However, prevalence in lead exposure remained similar in juvenile black ducks (from 8.2% to 8.3%). Additional evidence from lead ingestion and lead poisoning mortality events also indicates that lead exposure has declined in waterfowl in the Mississippi flyway. We believe that lead ingestion will continue to decline, despite the persistence of lead shot in some wetlands. The impact of reduced lead exposure on waterfowl populations needs to be assessed.

  1. Australia's leading public health body delays action on the revision of the public health goal for blood lead exposures.

    PubMed

    Taylor, Mark Patrick; Winder, Chris; Lanphear, Bruce P

    2014-09-01

    Globally, childhood blood lead levels have fallen precipitously in developed countries since the 1970s following action by international bodies such as the WHO and Food and Agricultural Organization (FAO) of the United Nations. These reductions have been affected by the activities of national agencies such as the US EPA and US Centers for Disease Control and Prevention in the establishment of air lead and blood lead standards, the introduction of legislation to remove lead from petrol, paint and consumer products and tighter restrictions on lead emissions. The outcome of recent major international reviews of research into the effects of low-level lead exposures (e.g. by WHO, USA health and environmental agencies, German and Canadian health bodies) has resulted in recommendations to reduce and eliminate lead exposures. By contrast, Australian policy responses to the incontrovertible evidence that adverse neurocognitive and behavioural effects that occur at levels well below the current national goal of 10μg/dL have stalled. The delayed response by Australia occurs at a time when blood lead levels in two of Australia's three primary lead mining and smelting cities: Port Pirie, South Australia and Broken Hill, New South Wales, are rising. In the third city, Mount Isa, Queensland, there is still no systematic, annual testing of childhood blood lead values. This is despite the fact that Mount Isa has the highest lead (and other toxic metals such as cadmium and arsenic) emissions to the environment (120tonnes of lead in 2011/12) from any single point source in Australia. It is clear that both state and national policy approaches to the ongoing risks of lead exposure need to be revised urgently and in line with contemporary international standards. Recommended changes should include a new lower blood lead intervention level of no more than 5μg/dL, with a national goal for all children under 5years of age to have a blood lead level of below 1μg/dL by 2020. In order to

  2. NEUROBEHAVIORAL CONSEQUENCES OF LOW LEAD EXPOSURE IN CHILDHOOD

    EPA Science Inventory

    Children attending non-remedial first and second grades were classified according to the concentration of lead in their shed deciduous teeth. Children in the lowest and highest tenth percentile were studied with a detailed neuropsychological battery under blind conditions. Thirty...

  3. Lead exposure: Public and occupational health hazards. (Latest citations from Pollution abstracts). Published Search

    SciTech Connect

    1995-12-01

    The bibliography contains citations concerning the effects of chronic lead exposure in humans and animals. The citations explore lead exposure resulting from occupational hazards, automobile emissions, and air pollution. Lead absorption in children is discussed. The clinical features of lead toxicity are noted, and biochemical assays for the quantification of blood and tissue lead levels are discussed. D-aminolevulinic acid dehydratase and its relation to blood lead levels are cited.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  4. Lead shot contribution to blood lead of First Nations people: the use of lead isotopes to identify the source of exposure.

    PubMed

    Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

    2008-11-01

    Although lead isotope ratios have been used to identify lead ammunition (lead shotshell pellets and bullets) as a source of exposure for First Nations people of Canada, the actual source of lead exposure needs to be further clarified. Whole blood samples for First Nations people of Ontario, Canada, were collected from participants prior to the traditional spring harvest of water birds, as well as post-harvest. Blood-lead levels and stable lead isotope ratios prior to, and after the harvest were determined by ICP-MS. Data were analyzed by paired t-tests and Wilcoxon Signed-Ranks tests. All participants consumed water birds harvested with lead shotshell during the period of study. For the group excluding six males who were potentially exposed to other sources of lead (as revealed through a questionnaire), paired t-tests and Wilcoxon Signed-Ranks tests showed consistent results: significant (p<0.05) increases in blood-lead concentrations and blood levels of (206)Pb/(204)Pb and (206)Pb/(207)Pb towards the mean values we previously reported for lead shotshell pellets; and a significant decrease in (208)Pb/(206)Pb values towards the mean for lead shotshell pellets. However, when we categorized the group further into a group that did not use firearms and did not eat any other traditional foods harvested with lead ammunition other than waterfowl, our predictions for (206)Pb/(204)Pb, (206)Pb/(207)Pb and (208)Pb/(206)Pb hold true, but there was not a significant increase in blood-lead level after the hunt. It appears that the activity of hunting (i.e., use of a shotgun) was also an important route of lead exposure. The banning of lead shotshell for all game hunting would eliminate a source of environmental lead for all people who use firearms and/or eat wild game. PMID:18678397

  5. Occupational Determinants of Cumulative Lead Exposure: Analysis of Bone Lead Among Men in the VA Normative Aging Study

    PubMed Central

    Ji, John S.; Schwartz, Joel; Sparrow, David; Hu, Howard; Weisskopf, Marc G.

    2014-01-01

    Objectives To examine the relation between occupation and cumulative lead exposure—assessed by measuring bone lead—in a community-dwelling population Method We measured bone lead concentration with K-shell X-Ray Fluorescence in 1,320 men in the Normative Aging Study. We categorized job titles into 14 broad US Census Bureau categories. We used ordinary least squares regression to estimate bone lead by job categories adjusted for other predictors. Results Service Workers, Construction and Extractive Craft Workers, and Installation, Maintenance and Repair Craft Workers had the highest bone lead concentrations. Including occupations significantly improved the overall model (p<0.001) and reduced by −15% to −81% the association between bone lead and education categories. Conclusion Occupation significantly predicts cumulative lead exposure in a community-dwelling population, and accounts for a large proportion of the association between education and bone lead. PMID:24709766

  6. Towards the prevention of lead exposure in South Africa: contemporary and emerging challenges.

    PubMed

    Mathee, Angela

    2014-12-01

    The prevention of lead exposure continues to constitute a major public health challenge in developed countries. In well-resourced countries major lead exposure reduction interventions have resulted in significant improvements in childhood blood lead distributions. In developing countries on the other hand, while lead exposure and poisoning remain serious public health concerns, a range of prevailing factors and circumstances, such as poverty, a large informal sector, competing public health challenges, low levels of awareness of lead hazards and weak capacity to enforce legislation, contribute to an increase in the scale and intensity of the challenge, and limit the prospects of comparable success in the foreseeable future. This paper collates available information to illustrate that despite some progress, a wide range of sources of lead exist in South Africa, and that certain settings and groups continue to be at high risk of lead exposure. Lead exposure in relation to paint, mining, lead melting in subsistence fishing communities, the consumption of Ayurvedic medicines and food production is described, and discussed with regard to the key factors hindering efforts to prevent lead poisoning and exposure in South Africa and many other developing countries. PMID:25086205

  7. [Risk assessment of lead exposure from different intake pathways for children in Wuhan City].

    PubMed

    Hao, Han-Zhou; Chen, Tong-Bin; Wu, Ji-Liang; Lei, Mei; Tian, Hui; Zu, Wen-Pu; Zhong, Xue-Bin

    2012-06-01

    70 sampling points were set in Wuhan City to collect soil, dust, air and food samples. According to the U. S. EPA recommended childhood lead exposure parameters, U. S. EPA human exposure risk assessment method was used to assess the potential health risk of different pathway exposures of children in Wuhan City to lead. The results of calculation show: Wuhan urban children's daily lead exposure is 1.20 x 10(-3) mg x (kg x d)(-1). The digestive tract is the main way for children's exposure to lead, with the exposure of 1.04 x 10(-3) mg x (kg x d)(-1), followed by the respiratory route and dermal absorption route, the exposures were 0.153 x 10(-3) mg x (kg x d)(-1) and 8.56 x 10(-7) mg x (kg x d)(-1) respectively. Pathways of the digestive tract, ingestion of soil or dust lead exposure accounted for 52.0% of the total exposure, through the digestive tract of soil or dust ingestion is the main route of exposure. Monte-Carlo method was used to simulate the pathway in the digestive tract, the amount of lead exposure through ingestion of soil was 2. 48 x 10(-2) mg x d(-1). The probability that exceeded the PTDI (Provisional Tolerable Daily Intake) specified by JECFA (The Joint FAO/WHO Expert Committee on Food Additives) was 2.1%. The results of the risk assessment indicate that lead exposure risks from the digestive tract, respiratory tract, skin absorption are less than the maximum acceptable risk level 5.0 x 10(-5) respectively and the risk associated with skin absorption of lead is less than the negligible risk level 1 x 10(-8). Application of Kriging interpolation method, Wuhan City children lead exposure value on spatial distribution were obtained, and Qingshan district and Jiangan district have a high level of children lead exposure. The aggregate risk index of Wuhan City children lead exposure was yield by using the indicator Kriging. PMID:22946198

  8. Decrements in neurobehavioral performance associated with mixed exposure to organic and inorganic lead.

    PubMed

    Schwartz, B S; Bolla, K I; Stewart, W; Ford, D P; Agnew, J; Frumkin, H

    1993-05-01

    In 1990, 222 current employees of a chemical facility in the eastern United States that manufactured tetraethyl lead were administered a neurobehavioral test battery, tests of olfactory function and peripheral vibration threshold, and questionnaires that assessed neuropsychiatric symptoms. A cumulative variable of exposure to inorganic and organic lead was derived from 12 years of personal industrial hygiene sampling data and an occupational history interview that assessed work in each of 29 exposure zones in the lead area. The range of assigned exposure intensities in these 29 zones was 4-119 micrograms/m3 for organic lead and 1-56 micrograms/m3 for inorganic lead. Cumulative lead exposure and exposure duration were defined as categorical variables (four groups) in multiple linear regression models. The adjusted mean differences in neurobehavioral test scores were estimated by comparing the average scores of the moderate, high, and highest exposure groups with the low exposure (reference) group. After adjustment for premorbid intellectual ability, age, race, and alcohol consumption, neurobehavioral test scores were poorer as measures of both cumulative lead exposure and exposure duration increased; many of the associations evidenced dose-response relations. Associations were observed in most cognitive and functional domains tested, but were most common in two domains: manual dexterity and verbal memory/learning. On the affected neuropsychologic measures, the groups with the highest exposure averaged scores 5-22% lower than those of the reference groups. Overall, the data revealed generally consistent and coherent associations between two measures of lead exposure and poorer neurobehavioral test performance. PMID:8317446

  9. Can a father's exposure lead to illness in his children

    SciTech Connect

    Stone, R.

    1992-10-02

    There is an urgent need for studies to elucidate mechanisms underlying evidence mechanisms underlying evidence that many different types of paternal exposure induce changes in sperm or semen that could affect children's health. Epidemiology, of course, is only half of the equation that describes male-mediated toxicity. The other half is the biological examination of mechanisms whereby damage to sperm might affect the next generation. In this area, geneticists and toxicologists have had a firm starting point: It's been known for decades that certain toxins and radiation can damage sperm. Research suggests that different chemicals exert their maximum damage on sperm at three stages of sperm production, with most chemicals tested affecting the stage during which early spermatozoa and late spermatids are formed. The problem, however, is that none of these defects has been linked specifically to certain types of birth defects or diseases.

  10. Environmental Lead Exposure among Preschool Children in Shanghai, China: Blood Lead Levels and Risk Factors

    PubMed Central

    Wang, Yu; Yu, Guangjun; Yan, Chonghuai

    2014-01-01

    Objective To determine blood lead levels and to identify related risk factors among children in Shanghai; to explore the lead change trend of children after industrial transformation and to provide data for policy development to control environmental lead pollution in Shanghai. Methods A stratified-clustered-random sampling method was used. A tungsten atomizer absorption spectrophotometer was employed to determine blood lead levels. Results The arithmetic mean, geometric mean and median of blood lead levels of 0- to 6-year-old children from Shanghai were 22.49 µg/L, 19.65 µg/L and 19.5 µg/L, including 0.26% (6/2291) with concentrations ≥100 µg/L and 2.7% (61/2291) with concentrations ≥50 µg/L. Boys' levels (23.57 µg/L) were greater than those of girls (21.2 µg/L). The blood lead levels increased with age. This survey showed that the Chongming district was the highest and Yangpu district was the lowest, this result is completely opposite with the earlier survey in Shanghai. Risk factors for lead contamination included housing environment, parents' education levels, social status, hobbies, and children's nutritional status. Conclusions The blood lead levels of children in Shanghai were lower than the earlier data of Shanghai and those of published studies in China, but higher than the blood lead levels of developed countries. The blood lead levels of urban districts are higher than the central districts with the industrial transformation. Society and the government should take an active interest in childhood lead poisoning of urban areas. PMID:25436459

  11. Occupational lead exposure among automotive garage workers – a case study for Jimma town, Ethiopia

    PubMed Central

    2012-01-01

    Background In Ethiopia, although there are numerous small-scale and medium industries which use lead-based raw materials that may pose health risks to workers, there are no workplace regulations for lead exposure. Moreover, there are no studies carried out on the blood lead levels (BLLs) of workers or on the contribution of common workplace practices to lead poisoning. Method A cross-sectional study on the BLLs of 45 automotive garage workers and 40 non-garage workers was carried out in the town of Jimma, Ethiopia. In addition to BLL analysis, data on some risk factors such as smoking, and chewing ‘khat’ (the leaves of Catha adulis) were gathered through structured questionnaires and interviews and data analysis was performed using SPSS (version 16). The t-test was used to compare mean BLLs of study groups. The analysis of variance (ANOVA), Kruskal-Wallis, Pearson chi-square and odds ratio tests were used to investigate the associations between specific job type, smoking and/or ‘khat’ chewing, service years and occurrence of non-specific symptoms with BLLs. Results The mean BLL of the automotive-garage workers was found to be significantly greater than that of the controls. The BLLs of all the lead-exposed individuals were found to be over 10 μg/dL, and 53% of them had BLLs ranging 12 – 20 μg/dL, with the remaining 47% having over 20 μg/dL. The BLL of the workers increased with the duration of working in an automotive garage. Individuals involved in manual car painting comprise a larger percentage (58%) of those with the highest BLLs (≥ 20 μg/dL). Lead accumulation in individuals who chew ‘khat’ in the work place was found to be faster than in those who are not used to chewing ‘khat’. ‘Khat’ is an evergreen shrub native to tropical East Africa, with dark green opposite leaves which are chewed when fresh for their stimulating effects. Conclusion The findings of the study have clearly demonstrated that the BLLs of automotive

  12. Urban gardens: lead exposure, recontamination mechanisms, and implications for remediation design.

    PubMed

    Clark, Heather F; Hausladen, Debra M; Brabander, Daniel J

    2008-07-01

    Environmental lead contamination is prevalent in urban areas where soil represents a significant sink and pathway of exposure. This study characterizes the speciation of lead that is relevant to local recontamination and to human exposure in the backyard gardens of Roxbury and Dorchester, MA, USA. One hundred forty-one backyard gardens were tested by X-ray fluorescence, and 81% of gardens have lead levels above the US EPA action limit of 400 microg/g. Raised gardening beds are the in situ exposure reduction method used in the communities to promote urban gardening. Raised beds were tested for lead and the results showed that the lead concentration increased from an initial range of 150+/-40 microg/g to an average of 336 microg/g over 4 years. The percent distribution of lead in the fine grain soil (<100 microm) and the trace metal signature of the raised beds support the conclusion that the mechanism of recontamination is wind-transported particles. Scanning electron microscopy and sequential extraction were used to characterize the speciation of lead, and the trace metal signature of the fine grain soil in both gardens and raised gardening beds is characteristic of lead-based paint. This study demonstrates that raised beds are a limited exposure reduction method and require maintenance to achieve exposure reduction goals. An exposure model was developed based on a suite of parameters that combine relevant values from the literature with site-specific quantification of exposure pathways. This model suggests that consumption of homegrown produce accounts for only 3% of children's daily exposure of lead while ingestion of fine grained soil (<100 microm) accounts for 82% of the daily exposure. This study indicates that urban lead remediation on a yard-by-yard scale requires constant maintenance and that remediation may need to occur on a neighborhood-wide scale. PMID:18456252

  13. Urban gardens: Lead exposure, recontamination mechanisms, and implications for remediation design

    SciTech Connect

    Clark, Heather F. Hausladen, Debra M.; Brabander, Daniel J.

    2008-07-15

    Environmental lead contamination is prevalent in urban areas where soil represents a significant sink and pathway of exposure. This study characterizes the speciation of lead that is relevant to local recontamination and to human exposure in the backyard gardens of Roxbury and Dorchester, MA, USA. One hundred forty-one backyard gardens were tested by X-ray fluorescence, and 81% of gardens have lead levels above the US EPA action limit of 400 {mu}g/g. Raised gardening beds are the in situ exposure reduction method used in the communities to promote urban gardening. Raised beds were tested for lead and the results showed that the lead concentration increased from an initial range of 150{+-}40 {mu}g/g to an average of 336 {mu}g/g over 4 years. The percent distribution of lead in the fine grain soil (<100 {mu}m) and the trace metal signature of the raised beds support the conclusion that the mechanism of recontamination is wind-transported particles. Scanning electron microscopy and sequential extraction were used to characterize the speciation of lead, and the trace metal signature of the fine grain soil in both gardens and raised gardening beds is characteristic of lead-based paint. This study demonstrates that raised beds are a limited exposure reduction method and require maintenance to achieve exposure reduction goals. An exposure model was developed based on a suite of parameters that combine relevant values from the literature with site-specific quantification of exposure pathways. This model suggests that consumption of homegrown produce accounts for only 3% of children's daily exposure of lead while ingestion of fine grained soil (<100 {mu}m) accounts for 82% of the daily exposure. This study indicates that urban lead remediation on a yard-by-yard scale requires constant maintenance and that remediation may need to occur on a neighborhood-wide scale.

  14. Lead Exposure in Adult Males in Urban Transvaal Province, South Africa during the Apartheid Era

    PubMed Central

    Hess, Catherine A.; Cooper, Matthew J.; Smith, Martin J.; Trueman, Clive N.; Schutkowski, Holger

    2013-01-01

    Human exposure to lead is a substantial public health hazard worldwide and is particularly problematic in the Republic of South Africa given the country’s late cessation of leaded petrol. Lead exposure is associated with a number of serious health issues and diseases including developmental and cognitive deficiency, hypertension and heart disease. Understanding the distribution of lifetime lead burden within a given population is critical for reducing exposure rates. Femoral bone from 101 deceased adult males living in urban Transvaal Province (now Gauteng Province), South Africa between 1960 and 1998 were analyzed for lead concentration by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Of the 72 black and 29 white individuals sampled, chronic lead exposure was apparent in nearly all individuals. White males showed significantly higher median bone lead concentration (ME = 10.04 µg·g−1), than black males (ME = 3.80 µg·g−1) despite higher socioeconomic status. Bone lead concentration covaries significantly, though weakly, with individual age. There was no significant temporal trend in bone lead concentration. These results indicate that long-term low to moderate lead exposure is the historical norm among South African males. Unexpectedly, this research indicates that white males in the sample population were more highly exposed to lead. PMID:23505462

  15. Mapping the spatio-temporal risk of lead exposure in apex species for more effective mitigation.

    PubMed

    Mateo-Tomás, Patricia; Olea, Pedro P; Jiménez-Moreno, María; Camarero, Pablo R; Sánchez-Barbudo, Inés S; Rodríguez Martín-Doimeadios, Rosa C; Mateo, Rafael

    2016-07-27

    Effective mitigation of the risks posed by environmental contaminants for ecosystem integrity and human health requires knowing their sources and spatio-temporal distribution. We analysed the exposure to lead (Pb) in griffon vulture Gyps fulvus-an apex species valuable as biomonitoring sentinel. We determined vultures' lead exposure and its main sources by combining isotope signatures and modelling analyses of 691 bird blood samples collected over 5 years. We made yearlong spatially explicit predictions of the species risk of lead exposure. Our results highlight elevated lead exposure of griffon vultures (i.e. 44.9% of the studied population, approximately 15% of the European, showed lead blood levels more than 200 ng ml(-1)) partly owing to environmental lead (e.g. geological sources). These exposures to environmental lead of geological sources increased in those vultures exposed to point sources (e.g. lead-based ammunition). These spatial models and pollutant risk maps are powerful tools that identify areas of wildlife exposure to potentially harmful sources of lead that could affect ecosystem and human health. PMID:27466455

  16. Screening for lead exposure using a geographic information system

    SciTech Connect

    Wartenberg, D. )

    1992-12-01

    Screening programs for lead overexposure typically target high-risk populations by identifying regions with common risk markers (older housing, poverty, etc.). While more useful than untargeted screening programs, targeted programs are limited by the geographic resolution of the risk-factor information. A geographic information system can make screening programs more effective and more cost-efficient by mapping cases of overexposure, identifying high-incidence neighborhoods warranting screening, and validating risk-factor-based prediction rules. 5 refs., 5 figs., 2 tabs.

  17. Improved spatial targeting with directionally segmented deep brain stimulation leads for treating essential tremor

    NASA Astrophysics Data System (ADS)

    Keane, Maureen; Deyo, Steve; Abosch, Aviva; Bajwa, Jawad A.; Johnson, Matthew D.

    2012-08-01

    Deep brain stimulation (DBS) in the ventral intermediate nucleus of thalamus (Vim) is known to exert a therapeutic effect on postural and kinetic tremor in patients with essential tremor (ET). For DBS leads implanted near the caudal border of Vim, however, there is an increased likelihood that one will also induce paresthesia side-effects by stimulating neurons within the sensory pathway of the ventral caudal (Vc) nucleus of thalamus. The aim of this computational study was to (1) investigate the neuronal pathways modulated by therapeutic, sub-therapeutic and paresthesia-inducing DBS settings in three patients with ET and (2) determine how much better an outcome could have been achieved had these patients been implanted with a DBS lead containing directionally segmented electrodes (dDBS). Multi-compartment neuron models of the thalamocortical, cerebellothalamic and medial lemniscal pathways were first simulated in the context of patient-specific anatomies, lead placements and programming parameters from three ET patients who had been implanted with Medtronic 3389 DBS leads. The models showed that in these patients, complete suppression of tremor was associated most closely with activating an average of 62% of the cerebellothalamic afferent input into Vim (n = 10), while persistent paresthesias were associated with activating 35% of the medial lemniscal tract input into Vc thalamus (n = 12). The dDBS lead design demonstrated superior targeting of the cerebello-thalamo-cortical pathway, especially in cases of misaligned DBS leads. Given the close proximity of Vim to Vc thalamus, the models suggest that dDBS will enable clinicians to more effectively sculpt current through and around thalamus in order to achieve a more consistent therapeutic effect without inducing side-effects.

  18. Secondhand Tobacco Smoke: A Source of Lead Exposure in US Children and Adolescents

    PubMed Central

    Apostolou, Andria; Garcia-Esquinas, Esther; Fadrowski, Jeffrey J.; McLain, RN, Pat; Weaver, Virginia M.

    2012-01-01

    Objectives. We evaluated the relationship between secondhand tobacco smoke (SHS) exposure and blood lead levels in US children and adolescents. Methods. We analyzed data from 6830 participants aged 3–19 years in the National Health and Nutrition Examination Survey (1999–2004) who were not active smokers and for whom SHS exposure information and blood lead measurements were available. Results. After multivariable adjustment, participants in the highest quartile of serum cotinine (≥ 0.44 μg/L) had 28% (95% confidence interval = 21%, 36%) higher blood lead levels than had those in the lowest quartile (< 0.03 μg/L). Similarly, blood lead levels were 14% and 24% higher in children who lived with 1 or with 2 or more smokers, respectively, than they were in children living with no smokers. Among participants for whom lead dust information was available, the associations between SHS and blood lead levels were similar before and after adjustment for lead dust concentrations. Conclusions. SHS may contribute to increased blood lead levels in US children. Lead dust does not appear to mediate this association, suggesting inhalation as a major pathway of exposure. Eliminating SHS exposure could reduce lead exposure in children. PMID:21852639

  19. Impact of developmental lead exposure on splenic factors

    SciTech Connect

    Kasten-Jolly, Jane; Heo, Yong; Lawrence, David A.

    2010-09-01

    Lead (Pb) is known to alter the functions of numerous organ systems, including the hematopoietic and immune systems. Pb can induce anemia and can lower host resistance to bacterial and viral infections. The anemia is due to Pb's inhibition of hemoglobin synthesis and Pb's induction of membrane changes, leading to early erythrocyte senescence. Pb also increases B-cell activation/proliferation and skews T-cell help (Th) toward Th2 subset generation. The specific mechanisms for many of the Pb effects are, as yet, not completely understood. Therefore, we performed gene expression analysis, via microarray, on RNA from the spleens of developmentally Pb-exposed mice, in order to gain further insight into these Pb effects. Splenic RNA microarray analysis indicated strong up-regulation of genes coding for proteolytic enzymes, lipases, amylase, and RNaseA. The data also showed that Pb affected the expression of many genes associated with innate immunity. Analysis of the microarray results via GeneSifter software indicated that Pb increased apoptosis, B-cell differentiation, and Th2 development. Direct up-regulation by Pb of expression of the gene encoding the heme-regulated inhibitor (HRI) suggested that Pb can decrease erythropoiesis by blocking globin mRNA translation. Pb's high elevation of digestive/catabolizing enzymes could generate immunogenic self peptides. With Pb's potential to induce new self-peptides and to enhance the expression of caspases, cytokines, and other immunomodulators, further evaluation of Pb's involvement in autoimmune phenomena, especially Th2-mediated autoantibody production, and alteration of organ system activities is warranted.

  20. Childhood lead toxicity and impaired release of thyrotropin-stimulating hormone

    SciTech Connect

    Huseman, C.A.; Moriarty, C.M.; Angle, C.R.

    1987-04-01

    Decreased stature of children is epidemiologically associated with increased blood lead independent of multiple socioeconomic and nutritional variables. Since endocrine dysfunction occurs in adult lead workers, they studied two girls, 2 years of age, before and after calcium disodium edetate chelation for blood leads (PbB) of 19-72 ..mu..g/dl. The height of both children had crossed from the 50th to below the 10th percentile during the course of chronic lead toxicity. Basal free T/sub 4/, T/sub 4/, T/sub 3/, cortisol, somatomedin C, and sex steroids were normal. A decrease in the growth hormone response and elevation of basal prolcatin and gonadotropins were noted in one. Both children demonstrated blunted thyrotropin-stimulating hormone (TSH) responses to thyrotropin-releasing hormone (TRH) in six of seven challenges. This prompted in vitro studies of cultured cells from rat pituitarities. After incubation of pituitary cells with 0.1-10 ..mu..M Pb/sup 2 +/ for 2 hr, followed by the addition of TRH, there was a dose-dependent inhibition of TSH release Lead did not interfere with the assay of TSH. To investigate the interaction of lead and calcium, /sup 45/Ca/sup 2 +/ kinetic analyses were done on rat pituitary slices after 1 hr incubation with 1.0 ..mu..M lead. The impaired late efflux was consistent with a decrease in the size and exchangeability of the tightly bound pool of intracellular microsomal or mitochondrial calcium. The rat pituitary cell model provides a model for the decreased TSH release of lead poisoning, supports the biological plausibility of a neuroendocrine effect on growth, and suggests that interference with calcium-mediated intracellular responses is a basic mechanism of lead toxicity.

  1. Effect of sublethal lead exposure on gastric motility of red-tailed hawks.

    PubMed

    Lawler, E M; Duke, G E; Redig, P T

    1991-07-01

    In order to determine the effects of low level lead exposure on gastric motility in raptors, strain gage transducers were surgically implanted on the serosal surface of the muscular stomach of three red-tailed hawks. The frequency and amplitude of gastric contractions during ingestion and early digestion were monitored for 1 week under control conditions and for 3 weeks while the birds were fed 0.82 or 1.64 mg lead (as lead acetate) per kg body weight each day. Exposure to these doses did not appreciably affect either the frequency or amplitude of gastric contractions in these birds. This low level lead exposure also had no consistent effect on the regular egestion of pellets of undigested material by hawks. Daily exposure to doses up to 6.55 mg lead/kg body weight did not affect the frequency or timing of pellet egestion, and exposure to 1.64 mg lead/kg did not affect the gastric contractions associated with pellet egestion. Although gastrointestinal dysfunction is often associated with clinical cases of acute lead toxicity, chronic exposure to these low levels of lead acetate did not significantly alter gastric motility in red-tailed hawks. PMID:1898121

  2. Combining datasets to predict the effects of regulation of environmental lead exposure in housing stock.

    PubMed

    Strauss, W J; Carroll, R J; Bortnick, S M; Menkedick, J R; Schultz, B D

    2001-03-01

    A model for children's blood lead concentrations as a function of environmental lead exposures was developed by combining two nationally representative sources of data that characterize the marginal distributions of blood lead and environmental lead with a third regional dataset that contains joint measures of blood lead and environmental lead. The complicating factor addressed in this article was the fact that methods for assessing environmental lead were different in the national and regional datasets. Relying on an assumption of transportability (that although the marginal distributions of blood lead and environmental lead may be different between the regional dataset and the nation as a whole, the joint relationship between blood lead and environmental lead is the same), the model makes use of a latent variable approach to estimate the joint distribution of blood lead and environmental lead nationwide. PMID:11252599

  3. The Association between Environmental Lead Exposure and Bone Density in Children

    PubMed Central

    Campbell, James R.; Rosier, Randy N.; Novotny, Leonore; Puzas, J. Edward

    2004-01-01

    Osteoporosis is a decrease in bone mineral density (BMD) that predisposes individuals to fractures. Although an elderly affliction, a predisposition may develop during adolescence if a sufficient peak BMD is not achieved. Rat studies have found that lead exposure is associated with decreased BMD. However, human studies are limited. We hypothesized that the BMD of children with high lead exposure would be lower than the BMD of children with low lead exposure. We collected data on 35 subjects; 16 had low cumulative lead exposure (mean, 6.5 μg/dL), and 19 had high exposure (mean, 23.6 μg/dL). All were African American; there was no difference between the groups by sex, age, body mass index, socioeconomic status, physical activity, or calcium intake. Significant differences in BMD between low and high cumulative lead exposure were noted in the head (1.589 vs. 1.721 g/cm2), third lumbar vertebra (0.761 vs. 0.819 g/cm2), and fourth lumbar vertebra (0.712 vs. 0.789 g/cm2). Contrary to our hypothesis, subjects with high lead exposure had a significantly higher BMD than did subjects with low lead exposure. This may reflect a true phenomenon because lead exposure has been reported to accelerate bony maturation by inhibiting the effects of parathyroid hormone–related peptide. Accelerated maturation of bone may ultimately result in a lower peak BMD being achieved in young adulthood, thus predisposing to osteoporosis in later life. Future studies need to investigate this proposed model. PMID:15289167

  4. Prenatal lead exposure modifies the impact of maternal self-esteem on children's inattention behavior

    PubMed Central

    Xu, Jian; Hu, Howard; Wright, Rosalind; Sánchez, Brisa N.; Schnaas, Lourdes; Bellinger, David C.; Park, Sung Kyun; Martínez, Sandra; Hernández-Avila, Mauricio; Téllez-Rojo, Martha Maria; Wright, Robert O.

    2015-01-01

    Objective To prospectively evaluate the association of maternal self-esteem measured when their offspring were toddlers with the subsequent development of attention-deficit-hyperactivity-disorder (ADHD)-like behavior in their school-age offspring and the potential modifying effects of prenatal lead exposure. Study design We evaluated a subsample of 192 mother-child pairs from a long-running birth-cohort project that enrolled mothers in Mexico from 1994 to 2011. Prenatal lead exposure was assessed using cord blood lead and maternal bone lead around delivery (tibia and patella lead, measured by K-x-ray-fluorescence). When children were 2 years old, maternal self-esteem was measured using the Coopersmith-Self-esteem-Inventory. When children were 7-to-15 years old, children's blood lead levels and ADHD symptoms were assessed, and Conners’ Parental-Rating-Scales-Revised (CPRS-R) and Behavior-Rating-Inventory-of-Executive-Function-Parent Form (BRIEF-P) were used as measures of ADHD-like behavior. Results Adjusting for family economic status, marital status, maternal education and age, child's age and sex, and children's current blood lead levels, increased maternal self-esteem was associated with reduced child inattention behavior. Compared with those among high prenatal lead exposure (P25-P100), this association was stronger among low prenatal lead exposure groups (P1-P25, p-values for the interaction effects between prenatal lead exposure and maternal self-esteem levels < 0.10). Each 1-point increase in maternal self-esteem scores was associated with 0.6-to-1.3-point decrease in CPRS-R and BRIEF-P T-scores among groups with low cord blood lead and patella lead (P1-P25). Conclusions Children experiencing high maternal self-esteem during toddlerhood were less likely to develop inattention behavior at school-age. Prenatal lead exposure may play a role in attenuating this protective effect. PMID:26047683

  5. Exploring Childhood Lead Exposure through GIS: A Review of the Recent Literature

    PubMed Central

    Akkus, Cem; Ozdenerol, Esra

    2014-01-01

    Childhood exposure to lead remains a critical health control problem in the US. Integration of Geographic Information Systems (GIS) into childhood lead exposure studies significantly enhanced identifying lead hazards in the environment and determining at risk children. Research indicates that the toxic threshold for lead exposure was updated three times in the last four decades: 60 to 30 micrograms per deciliter (µg/dL) in 1975, 25 µg/dL in 1985, and 10 µb/dL in 1991. These changes revealed the extent of lead poisoning. By 2012 it was evident that no safe blood lead threshold for the adverse effects of lead on children had been identified and the Center for Disease Control (CDC) currently uses a reference value of 5 µg/dL. Review of the recent literature on GIS-based studies suggests that numerous environmental risk factors might be critical for lead exposure. New GIS-based studies are used in surveillance data management, risk analysis, lead exposure visualization, and community intervention strategies where geographically-targeted, specific intervention measures are taken. PMID:24945189

  6. Recruitment and blocking properties of the CardioFit stimulation lead

    NASA Astrophysics Data System (ADS)

    Ahilea Anholt, Tamar; Ayal, Shai; Goldberg, Joshua A.

    2011-06-01

    The CardioFit vagal stimulation system has been developed as a proposed therapy for congestive heart failure (CHF). CardioFit is to be implanted in several hundred CHF patients enrolled in the INOVATE-HF clinical trial, an FDA approved study. The CardioFit stimulation lead (CSL), which is a cuff electrode that delivers stimulation pulses to the right cervical vagus, was designed to recruit efferent cardiac vagal fibers while minimizing unwanted recruitment of other fibers. This paper presents the CSL and measurements of its recruiting and blocking properties when placed on isolated porcine vagus nerves maintained at an elevated temperature in oxygenated artificial cerebrospinal fluid. Using charge balanced quasi-trapezoidal pulses driven through the CSL, we show in eight out of nine nerves a 63% ± 13% (mean ± SD) unidirectional attenuation of the A-fiber compound action potential attained at a current of 3.0 ± 0.8 mA. The threshold for the activation of A- and B-fibers was found to be 0.3 ± 0.17 mA and 2.5 ± 1.1 mA, respectively. The results presented here should help to guide the optimal parameters used in the upcoming deployment of the CardioFit system.

  7. Lead Exposure in Free-Flying Turkey Vultures Is Associated with Big Game Hunting in California

    PubMed Central

    Kelly, Terra R.; Johnson, Christine K.

    2011-01-01

    Predatory and scavenging birds are at risk of lead exposure when they feed on animals injured or killed by lead ammunition. While lead ammunition has been banned from waterfowl hunting in North America for almost two decades, lead ammunition is still widely used for hunting big game and small game animals. In this study, we evaluated the association between big game hunting and blood lead concentration in an avian scavenger species that feeds regularly on large mammals in California. We compared blood lead concentration in turkey vultures within and outside of the deer hunting season, and in areas with varying wild pig hunting intensity. Lead exposure in turkey vultures was significantly higher during the deer hunting season compared to the off-season, and blood lead concentration was positively correlated with increasing wild pig hunting intensity. Our results link lead exposure in turkey vultures to deer and wild pig hunting activity at these study sites, and we provide evidence that spent lead ammunition in carrion poses a significant risk of lead exposure to scavengers. PMID:21494326

  8. The conceptual structure of the integrated exposure uptake biokinetic model for lead in children.

    PubMed Central

    White, P D; Van Leeuwen, P; Davis, B D; Maddaloni, M; Hogan, K A; Marcus, A H; Elias, R W

    1998-01-01

    The integrated exposure uptake biokinetic model for lead in children was developed to provide plausible blood lead distributions corresponding to particular combinations of multimedia lead exposure. The model is based on a set of equations that convert lead exposure (expressed as micrograms per day) to blood lead concentration (expressed as micrograms per deciliter) by quantitatively mimicking the physiologic processes that determine blood lead concentration. The exposures from air, food, water, soil, and dust are modeled independently by several routes. Amounts of lead absorbed are modeled independently for air, food, water, and soil/dust, then combined as a single input to the blood plasma reservoir of the body. Lead in the blood plasma reservoir, which includes extracellular fluids, is mathematically allocated to all tissues of the body using age-specific biokinetic parameters. The model calculation provides the estimate for blood lead concentration for that age. This value is treated as the geometric mean of possible values for a single child, or the geometric mean of expected values for a population of children exposed to the same lead concentrations. The distribution of blood lead concentrations about this geometric mean is estimated using a geometric standard deviation, typically 1.6, derived from the analysis of well-conducted community blood studies. PMID:9860910

  9. Lead Exposure Is Associated with Decreased Serum Paraoxonase 1 (PON1) Activity and Genotypes

    PubMed Central

    Li, Wan-Fen; Pan, Mei-Hung; Chung, Meng-Chu; Ho, Chi-Kung; Chuang, Hung-Yi

    2006-01-01

    Lead exposure causes cardiac and vascular damage in experimental animals. However, there is considerable debate regarding the causal relationship between lead exposure and cardiovascular dysfunction in humans. Paraoxonase 1 (PON1), a high-density lipoprotein-associated antioxidant enzyme, is capable of hydrolyzing oxidized lipids and thus protects against atherosclerosis. Previous studies have shown that lead and several other metal ions are able to inhibit PON1 activity in vitro. To investigate whether lead exposure has influence on serum PON1 activity, we conducted a cross-sectional study of workers from a lead battery manufactory and lead recycling plant. Blood samples were analyzed for whole-blood lead levels, serum PON1 activity, and three common PON1 polymorphisms (Q192R, L55M, −108C/T). The mean blood lead level (± SD) of this cohort was 27.1 ± 15 μg/dL. Multiple linear regression analysis showed that blood lead levels were significantly associated with decreased serum PON1 activity (p < 0.001) in lead workers. This negative correlation was more evident for workers who carry the R192 allele, which has been suggested to be a risk factor for coronary heart disease. Taken together, our results suggest that the decrease in serum PON1 activity due to lead exposure may render individuals more susceptible to atherosclerosis, particularly subjects who are homozygous for the R192 allele. PMID:16882531

  10. Prospective associations between childhood low-level lead exposure and adult mental health problems: the Port Pirie cohort study.

    PubMed

    McFarlane, Alexander C; Searle, Amelia K; Van Hooff, Miranda; Baghurst, Peter A; Sawyer, Michael G; Galletly, Cherrie; Sim, Malcolm R; Clark, Levina S

    2013-12-01

    Low-level environmental lead exposure during childhood is associated with poorer emotional/behavioural functioning in later childhood and adolescence. Scarce research has examined whether these apparent effects persist into adulthood. This study is the first to examine prospective associations between lead exposure across early childhood and several common adult mental health problems. Childhood data (including blood lead concentrations) and adult data (from mental health questionnaires and psychiatric interviews) were available for 210 participants (44% males, mean age=26.3 years) from the Port Pirie cohort study (1979-1982 birth cohort). Participants had a mean childhood (to 7 years) average blood lead concentration of 17.2μg/dL. Among females, childhood blood lead showed small significant positive associations with lifetime diagnoses of drug and alcohol abuse and social phobia, and with anxiety, somatic and antisocial personality problems. For example: for a 10μg/dL blood lead increase, females were 2.84 times (95% CI 1.10, 7.30) more likely to have an alcohol abuse diagnosis. However, adjustment for childhood covariates - particularly stimulation within the home environment - rendered these associations non-significant. No significant or sizeable unadjusted or adjusted associations were seen for males. The associations between early lead exposure and emotional/behavioural functioning in children might persist into adulthood, at least for females. However, it is unclear whether such results arise from residual confounding, or other mechanisms. Interventions that focus on improving the childhood home environment may have a long-term positive impact on adult mental health outcomes. However, more prospective research using large and representative samples is needed to substantiate these results. PMID:23958641

  11. Cadmium but not lead exposure affects Xenopus laevis fertilization and embryo cleavage.

    PubMed

    Slaby, Sylvain; Lemière, Sébastien; Hanotel, Julie; Lescuyer, Arlette; Demuynck, Sylvain; Bodart, Jean-François; Leprêtre, Alain; Marin, Matthieu

    2016-08-01

    Among the toxicological and ecotoxicological studies, few have investigated the effects on germ cells, gametes or embryos, while an impact at these stages will result in serious damage at a population level. Thus, it appeared essential to characterize consequences of environmental contaminant exposures at these stages. Therefore, we proposed to assess the effects of exposure to cadmium and lead ions, alone or in a binary mixture, on early stages of Xenopus laevis life cycle. Fertilization and cell division during segmentation were the studied endpoints. Cadmium ion exposures decreased in the fertilization rates in a concentration-dependent manner, targeting mainly the oocytes. Exposure to this metal ions induced also delays or blockages in the embryonic development. For lead ion exposure, no such effect was observed. For the exposure to the mixture of the two metal ions, concerning the fertilization success, we observed results similar to those obtained with the highest cadmium ion concentration. PMID:27218424

  12. Brief oral stimulation, but especially oral fat exposure, elevates serum triglycerides in humans.

    PubMed

    Mattes, Richard D

    2009-02-01

    Oral exposure to dietary fat results in an early initial spike, followed by a prolonged elevation, of serum triglycerides in humans. The physiological and pathophysiological implications remain unknown. This study sought to determine the incidence of the effect, the required fat exposure duration, and its reliability. Thirty-four healthy adults participated in four to six response-driven trials held at least a week apart. They reported to the laboratory after an overnight fast, a catheter was placed in an antecubital vein, and a blood sample was obtained. Participants then ingested 50 g of safflower oil in capsules with 500 ml of water within 15 min to mimic a high fat meal but without oral fat exposure. Blood was collected 0, 10, 20, 30, 40, 50, 60, 120, 240, 360, and 480 min after capsule ingestion with different forms (full fat, nonfat, none) and durations of oral fat exposures (10 s, 5 min, 20 min, and/or 2 h). A triglyceride response (increase of triglyceride >10 mg/dl within 30 min) was observed in 88.2%, 70.5%, and 50% of participants with full-fat, nonfat, and no oral exposure, respectively. Test-retest reliability was 75% with full-fat exposure but only 45.4% with nonfat exposure. Full-fat and nonfat exposures led to comparable significant elevations of triglyceride over no oral stimulation with 10-s exposures, but full fat led to a greater rise than nonfat with 20 min of exposure. These data indicate that nutritionally relevant oral fat exposures reliably elevate serum triglyceride concentrations in most people. PMID:19074638

  13. A safe strategy to decrease fetal lead exposure in a woman with chronic intoxication.

    PubMed

    Leiba, Adi; Hu, Howard; Zheng, Amin; Kales, Stefanos N

    2010-08-01

    During pregnancy skeletal lead is mobilized by maternal bone turnover and can threaten fetal development. The exact strategy suggested to women of childbearing age, who were chronically exposed to lead, and, thus, have high bone lead burden, is not well established. We describe 4 years of follow-up of a 29-year-old woman with chronic lead intoxication. We (a) advised her to delay conception until 'toxicological clearance', (b) treated her with multiple courses of lead chelator, DMSA, and (c) prescribed oral calcium. Patient had low blood lead and protoporphyrin level during pregnancy until delivery. Delaying conception, lead chelation, and calcium supplementation can decrease fetal exposure. PMID:20459344

  14. Lead Exposures in U.S. Children, 2008: Implications for Prevention

    PubMed Central

    Levin, Ronnie; Brown, Mary Jean; Kashtock, Michael E.; Jacobs, David E.; Whelan, Elizabeth A.; Rodman, Joanne; Schock, Michael R.; Padilla, Alma; Sinks, Thomas

    2008-01-01

    Objective We reviewed the sources of lead in the environments of U.S. children, contributions to children’s blood lead levels, source elimination and control efforts, and existing federal authorities. Our context is the U.S. public health goal to eliminate pediatric elevated blood lead levels (EBLs) by 2010. Data sources National, state, and local exposure assessments over the past half century have identified risk factors for EBLs among U.S. children, including age, race, income, age and location of housing, parental occupation, and season. Data extraction and synthesis Recent national policies have greatly reduced lead exposure among U.S. children, but even very low exposure levels compromise children’s later intellectual development and lifetime achievement. No threshold for these effects has been demonstrated. Although lead paint and dust may still account for up to 70% of EBLs in U.S. children, the U.S. Centers for Disease Control and Prevention estimates that ≥30% of current EBLs do not have an immediate lead paint source, and numerous studies indicate that lead exposures result from multiple sources. EBLs and even deaths have been associated with inadequately controlled sources including ethnic remedies and goods, consumer products, and food-related items such as ceramics. Lead in public drinking water and in older urban centers remain exposure sources in many areas. Conclusions Achieving the 2010 goal requires maintaining current efforts, especially programs addressing lead paint, while developing interventions that prevent exposure before children are poisoned. It also requires active collaboration across all levels of government to identify and control all potential sources of lead exposure, as well as primary prevention. PMID:18941567

  15. White lead exposure among Danish police officers employed in fingerprint detection.

    PubMed

    Rabjerg, L; Jennum, P J; Mørck, H I

    1983-12-01

    White lead exposure among Danish police officers employed in fingerprint detection. Scand j work environ health 9 (1983) 511-513. White lead is often used by police officers employed in fingerprint detection (dactylography). On the basis of a case of mild lead intoxication in a police officer all 22 exposed police officers at the Bureau of Dactylographic Identification in Copenhagen were examined. All went through a clinical examination and blood lead determination. None of the participants showed any sign of lead intoxication. The median blood lead concentration was 0.97 mumol/l (10th-90th percentiles 0.72-1.44 mumol/l), a value definitely higher than the average of the general population matched for age and sex. A correlation between the weekly white lead exposure and blood lead concentration (r = 0.87, p less than 0.0001) was found among the participants. PMID:6673108

  16. Prenatal or lactational exposure of male rats to lead acetate. Effect on reproductive function

    SciTech Connect

    Thoreux-Manlay, A.; Pinon-Lataillade, G.; Coffigny, H.; Masse, R.; Soufir, J.C.

    1995-02-01

    Lead is an environmental pollutant which has received much attention, partly because of the particular sensitivity of children to this element. As regards the consequences of exposure to lead during fetal life or childhood, epidemiological studies have so far focused on its neuropsychological effects and little is known about the consequences of fetal or childhood exposure for reproduction. With respect to animals, the reproductive toxicity of lead in males exposed during prenatal life or the suckling period has only been considered in a few studies. Four such studies concerned the rat, the most current model of lead toxicity for male reproduction; two of studies considered the long term effects (i.e. during adulthood) of moderate in utero lead exposure, another covered the prenatal and neonatal periods and focused on the possible impact of lead intoxication on steriodogenesis before weaning, while the remaining study dealt with pituitary hormone level at the end of lead gavage in newborns. None of these investigations compared the effects of exposure during prenatal life to those of exposure via lactation, or the early effects (at about weaning time) to the long-term consequences during adulthood. Because of the paucity of data on these points, we conducted two experiments: in one, rats were exposed to lead prenatally, and in the other via maternal milk. In both cases male reproductive function at weaning and adulthood was examined. 12 refs., 1 fig., 2 tabs.

  17. Cumulative Lead Exposure and Age-related Hearing Loss: The VA Normative Aging Study

    PubMed Central

    Park, Sung Kyun; Elmarsafawy, Sahar; Mukherjee, Bhramar; Spiro, Avron; Vokonas, Pantel S.; Nie, Huiling; Weisskopf, Marc G.; Schwartz, Joel; Hu, Howard

    2010-01-01

    Although lead has been associated with hearing loss in occupational settings and in children, little epidemiologic research has been conducted on the impact of cumulative lead exposure on age-related hearing loss in the general population. We determined whether bone lead levels, a marker of cumulative lead exposure, are associated with decreased hearing ability in 448 men from the Normative Aging Study, seen between 1962 and 1996 (2,264 total observations). Air conduction hearing thresholds were measured at 0.25 to 8 kHz and pure tone averages (PTA) (mean of 0.5, 1, 2 and 4 kHz) were computed. Tibia and patella lead levels were measured using K x-ray fluorescence between 1991 and 1996. In cross-sectional analyses, after adjusting for potential confounders including occupational noise, patella lead levels were significantly associated with poorer hearing thresholds at 2, 3, 4, 6 and 8 kHz and PTA. The odds of hearing loss significantly increased with patella lead levels. We also found significant positive associations between tibia lead and the rate change in hearing thresholds at 1, 2, and 8 kHz and PTA in longitudinal analyses. Our results suggest that chronic low-level lead exposure may be an important risk factor for age-related hearing loss and reduction of lead exposure could help prevent or delay development of age-related hearing loss. PMID:20638461

  18. Cumulative Exposure to Lead in Relation to Cognitive Function in Older Women

    PubMed Central

    Weuve, Jennifer; Korrick, Susan A.; Weisskopf, Marc A.; Ryan, Louise M.; Schwartz, Joel; Nie, Huiling; Grodstein, Francine; Hu, Howard

    2009-01-01

    Background Recent data indicate that chronic low-level exposure to lead is associated with accelerated declines in cognition in older age, but this has not been examined in women. Objective We examined biomarkers of lead exposure in relation to performance on a battery of cognitive tests among older women. Methods Patella and tibia bone lead—measures of cumulative exposure over many years—and blood lead, a measure of recent exposure, were assessed in 587 women 47–74 years of age. We assessed their cognitive function 5 years later using validated telephone interviews. Results Mean ± SD lead levels in tibia, patella, and blood were 10.5 ± 9.7 μg/g bone, 12.6 ± 11.6 μg/g bone, and 2.9 ± 1.9 μg/dL, respectively, consistent with community-level exposures. In multivariable-adjusted analyses of all cognitive tests combined, levels of all three lead biomarkers were associated with worse cognitive performance. The association between bone lead and letter fluency score differed dramatically from the other bone lead-cognitive score associations, and exclusion of this particular score from the combined analyses strengthened the associations between bone lead and cognitive performance. Results were statistically significant only for tibia lead: one SD increase in tibia lead corresponded to a 0.051-unit lower standardized summary cognitive score (95% confidence interval: −0.099 to −0.003; p = 0.04), similar to the difference in cognitive scores we observed between women who were 3 years apart in age. Conclusions These findings suggest that cumulative exposure to lead, even at low levels experienced in community settings, may have adverse consequences for women’s cognition in older age. PMID:19440496

  19. Lead Exposure Risk from Trash Ingestion by the Endangered California Condor (Gymnogyps californianus).

    PubMed

    Finkelstein, Myra E; Brandt, Joseph; Sandhaus, Estelle; Grantham, Jesse; Mee, Allan; Schuppert, Patricia Jill; Smith, Donald R

    2015-10-01

    Lead poisoning from ingestion of spent lead ammunition is one of the greatest threats to the recovery of California Condors (Gymnogyps californianus) in the wild. Trash ingestion by condors is well documented, yet the extent that trash presents a lead exposure risk is unknown. We evaluated 1,413 trash items collected from condor nest areas and nestlings in the Transverse Range of Ventura County, California, US, from 2002 to 2008, for their potential as a lead exposure risk to condors. We visually identified 71 items suspected to contain sufficient lead to be of toxicologic concern. These items were leached with weak acid and analyzed for lead. Twenty-seven of the 71 leached items (~2% of the 1,413 items) were "lead containing" based on criteria of a leachate lead concentration >1 μg/mL, with the majority of these items (22; 81% of the 27 lead items) being ammunition related (e.g., spent bullet casings and jacketed bullets). Only three of the 1,413 items collected were lead containing but were clearly not ammunition related; the other two lead-containing items were unidentified. Our results suggest that trash ingestion of nonammunition items does not pose a significant lead exposure risk to the California Condor population in California. PMID:26251991

  20. Lead exposure and rate of change in cognitive function in older women

    PubMed Central

    Power, Melinda C; Korrick, Susan; Tchetgen Tchetgen, Eric J; Nie, Linda H; Grodstein, Francine; Hu, Howard; Weuve, Jennifer; Schwartz, Joel; Weisskopf, Marc G

    2014-01-01

    Background Higher long-term cumulative lead exposure predicts faster cognitive decline in older men, but evidence of an association in women is lacking. Objective To determine if there is an association between lead exposure and cognitive decline in women. Methods This study considers a sample of 584 women from the Nurses’ Health Study who live in or near Boston, Massachusetts. We quantified lead exposure using biomarkers of lead exposure assessed in 1993–2004 and evaluated cognitive decline by repeated performance on a telephone battery of cognitive tests primarily assessing learning, memory, executive function, and attention completed in 1995–2008. All cognitive test scores were z-transformed for use in analyses. We used linear mixed models with random effects to quantify the association between each lead biomarker and change in cognition overall and on each individual test. Results Consideration of individual tests showed greater cognitive decline with increased tibia lead concentrations, a measure of long-term cumulative exposure, for story memory and category fluency. The estimated excess annual decline in overall cognitive test z-score per SD increase in tibia bone lead concentration was suggestive, although the confidence intervals included the null (0.024 standard units, 95% confidence interval: −0.053 , 0.004 – an additional decline in function equivalent to being 0.33 years older). We found little support for associations between cognitive decline and patella or blood lead, which provide integrated measures of exposure over shorter timeframes. Conclusions Long-term cumulative lead exposure may be weakly associated with faster cognitive decline in community-dwelling women, at least in some cognitive domains. PMID:24529005

  1. Influence of occupational low-level lead exposure on renal parameters

    SciTech Connect

    Verschoor, M.; Wibowo, A.; Herber, R.; van Hemmen, J.; Zielhuis, R.

    1987-01-01

    The influence of lead exposure on renal function was examined. In 155 lead workers and 126 control workers, lead in blood (PbB) and zinc protoporphyrin in blood (ZPP) were measured as indicators of exposure to lead; various proteins in urine were measured as parameters of renal functions. Regression and matched-pair analyses suggest that tubular parameters may be more influenced by lead exposure than glomerular parameters. Changes in renal function parameters may already occur at PbB levels below 3 mumol/liter (600 micrograms/liter). The excretion of N-acetyl-beta-D-glucosaminidase appears to be the most consistent and sensitive parameter of an early effect on the tubular function.

  2. Integrated exposure uptake biokinetic model for lead in children: empirical comparisons with epidemiologic data.

    PubMed

    Hogan, K; Marcus, A; Smith, R; White, P

    1998-12-01

    The concept of model validation is evolving in the scientific community. This paper addresses the comparison of observed and predicted estimates as one component of model validation as applied to the integrated exposure uptake biokinetic (IEUBK) model for lead in children. The IEUBK model is an exposure (dose)-response model that uses children's environmental lead exposures to estimate risk of elevated blood lead (typically > 10 micrograms/dl) through estimation of lead body burdens in a mass balance framework. We used residence-specific environmental lead measurements from three epidemiologic datasets as inputs for the IEUBK model to predict blood lead levels, and compared these predictions with blood lead levels of children living at these residences. When the IEUBK modeling focused on children with representative exposure measurements, that is, children who spent the bulk of their time near the locations sampled, there was reasonably close agreement between observed and predicted blood lead distributions in the three studies considered. Geometric mean observed and predicted blood lead levels were within 0.7 microgram/dl, and proportions of study populations expected to be above 10 micrograms/dl were within 4% of those observed. PMID:9860915

  3. Integrated exposure uptake biokinetic model for lead in children: empirical comparisons with epidemiologic data.

    PubMed Central

    Hogan, K; Marcus, A; Smith, R; White, P

    1998-01-01

    The concept of model validation is evolving in the scientific community. This paper addresses the comparison of observed and predicted estimates as one component of model validation as applied to the integrated exposure uptake biokinetic (IEUBK) model for lead in children. The IEUBK model is an exposure (dose)-response model that uses children's environmental lead exposures to estimate risk of elevated blood lead (typically > 10 micrograms/dl) through estimation of lead body burdens in a mass balance framework. We used residence-specific environmental lead measurements from three epidemiologic datasets as inputs for the IEUBK model to predict blood lead levels, and compared these predictions with blood lead levels of children living at these residences. When the IEUBK modeling focused on children with representative exposure measurements, that is, children who spent the bulk of their time near the locations sampled, there was reasonably close agreement between observed and predicted blood lead distributions in the three studies considered. Geometric mean observed and predicted blood lead levels were within 0.7 microgram/dl, and proportions of study populations expected to be above 10 micrograms/dl were within 4% of those observed. PMID:9860915

  4. Evaluation, diagnosis, and treatment of lead poisoning in a patient with occupational lead exposure: a case presentation.

    PubMed

    Herman, D'souza Sunil; Geraldine, Menezes; Venkatesh, Thuppil

    2007-01-01

    Amongst toxic heavy metals, lead ranks as one of the most serious environmental poisons all over the world. Exposure to lead in the home and the workplace results in health hazards to many adults and children causing economic damage, which is due to the lack of awareness of the ill effects of lead. We report the case of a 22 year old man working in an unorganized lead acid battery manufacturing unit, complaining about a longer history of general body ache, lethargy, fatigue, shoulder joint pain, shaking of hands and wrist drop. Patient had blue line at gingivodental junction. Central nervous system (CNS) examination showed having grade 0 power of extensors of right wrist & fingers. Reflexes: Supinator- absent, Triceps- weak and other deep tendon reflexes- normal. Investigations carried out during the admission showed hemoglobin levels of 8.3 g/dl and blood lead level of 128.3 mug/dl. The patient was subjected to chelation therapy, which was accompanied by aggressive environmental intervention and was advised not to return to the same environmental exposure situation. After repeated course of chelation therapy he has shown the signs of improvement and is on follow up presently. PMID:17718907

  5. Rat hippocampal glutamate and GABA release exhibit biphasic effects as a function of chronic lead exposure level.

    PubMed

    Lasley, S M; Gilbert, M E

    2002-03-01

    Previous work has suggested that the lead (Pb) exposure-induced decrease in K(+)-evoked hippocampal glutamate (GLU) release is an important factor in the elevated threshold and diminished magnitude reported for hippocampal long-term potentiation (LTP) in exposed animals. In addition, complex dose-effect relationships between Pb exposure level and LTP have been reported. This investigation was conducted to determine the effects of Pb on hippocampal GLU and GABA release as a function of exposure level. Rats were continuously exposed to 0.1, 0.2, 0.5, or 1.0% Pb in the drinking water beginning at gestational day 15-16. Hippocampal transmitter release was induced in adult males by perfusion of 150 mM K(+) in the presence of Ca(+2) (total release) through a microdialysis probe in one test session, followed by perfusion through a contralateral probe in the absence of Ca(+2) (Ca(+2)-independent release) in the second session. Chronic exposure produced decreases in total K(+)-stimulated hippocampal GLU and GABA release at exposure levels of 0.1-0.5% Pb. Maximal effects were seen in the 0.2% group (blood Pb = 40 microg/100 ml), and changes in total release could be directly traced to alterations in the Ca(+2)-dependent component. However, these effects were less evident in the 0.5% group and were no longer present in the 1.0% Pb group, thus defining U-shaped dose-effect relationships. Moreover, in the absence of Ca(+2) in the dialysis perfusate, K(+)-induced release was elevated in the 2 highest exposure groups, suggesting a Pb(+2)-induced enhancement in evoked release. This pattern of results indicates the presence of 2 actions of Pb on in vivo transmitter release: a more potent suppression of stimulated release seen at lower exposure levels (27-62 microg/100 ml) combined with Ca+2-mimetic actions to independently induce exocytosis that is exhibited at higher exposure levels (> or =62 microg/100 ml). Furthermore, significant similarities in the dose-effect relationships

  6. Spinal cord stimulation with implanted epidural paddle lead relieves chronic axial low back pain

    PubMed Central

    Stidd, David A; Rivero, Sergio; Weinand, Martin E

    2014-01-01

    Introduction Spinal cord stimulation (SCS) provides significant relief for lumbosacral radiculopathy refractory to both medical and surgical treatment, but historically only offers limited relief for axial low back pain (LBP). We aim to evaluate the response of chronic axial LBP treated with SCS using a surgically implanted epidural paddle lead. Materials and methods This is a retrospective review of a consecutive series of patients with exclusive LBP or predominant LBP associated with lower extremity (LE) pain evaluated and treated with SCS using an implanted paddle lead within the dorsal thoracic epidural space. Baseline LBP, and if present LE pain, were recorded using the visual analogue scale (VAS) at an initial evaluation. At a follow-up visit (a minimum of 12 months later), LBP and LE pain after a spinal cord stimulator implantation were again recorded using the VAS. Patients were also asked to estimate total LBP pain relief achieved. Results Patients with either exclusive (n=7) or predominant (n=2) axial LBP were treated with SCS by implantation of a paddle lead at an average spine level of T9. The baseline VAS score for LBP was 7.2; after a follow-up of 20 months, the score decreased to 2.3 (P=0.003). The LE pain VAS score decreased from 7.5 to 0.0 (P=0.103). Patients also reported a subjective 66.4% decrease of their LBP at follow-up. There were no surgical complications. Conclusions Axial LBP is refractory to many treatments, including SCS. SCS using a surgically implanted paddle electrode provides significant pain relief for chronic axial LPB, and is a safe treatment modality. PMID:25143753

  7. Electrode alignment of transverse tripoles using a percutaneous triple-lead approach in spinal cord stimulation.

    PubMed

    Sankarasubramanian, V; Buitenweg, J R; Holsheimer, J; Veltink, P

    2011-02-01

    The aim of this modeling study is to determine the influence of electrode alignment of transverse tripoles on the paresthesia coverage of the pain area in spinal cord stimulation, using a percutaneous triple-lead approach. Transverse tripoles, comprising a central cathode and two lateral anodes, were modeled on the low-thoracic vertebral region (T10-T12) using percutaneous triple-lead configurations, with the center lead on the spinal cord midline. The triple leads were oriented both aligned and staggered. In the staggered configuration, the anodes were offset either caudally (caudally staggered) or rostrally (rostrally staggered) with respect to the midline cathode. The transverse tripolar field steering with the aligned and staggered configurations enabled the estimation of dorsal column fiber thresholds (I(DC)) and dorsal root fiber thresholds (I(DR)) at various anodal current ratios. I(DC) and I(DR) were considerably higher for the aligned transverse tripoles as compared to the staggered transverse tripoles. The aligned transverse tripoles facilitated deeper penetration into the medial dorsal columns (DCs). The staggered transverse tripoles always enabled broad and bilateral DC activation, at the expense of mediolateral steerability. The largest DC recruited area was obtained with the rostrally staggered transverse tripole. Transverse tripolar geometries, using percutaneous leads, allow for selective targeting of either medial or lateral DC fibers, if and only if the transverse tripole is aligned. Steering of anodal currents between the lateral leads of the staggered transverse tripoles cannot target medially confined populations of DC fibers in the spinal cord. An aligned transverse tripolar configuration is strongly recommended, because of its ability to provide more post-operative flexibility than other configurations. PMID:21248383

  8. Electrode alignment of transverse tripoles using a percutaneous triple-lead approach in spinal cord stimulation

    NASA Astrophysics Data System (ADS)

    Sankarasubramanian, V.; Buitenweg, J. R.; Holsheimer, J.; Veltink, P.

    2011-02-01

    The aim of this modeling study is to determine the influence of electrode alignment of transverse tripoles on the paresthesia coverage of the pain area in spinal cord stimulation, using a percutaneous triple-lead approach. Transverse tripoles, comprising a central cathode and two lateral anodes, were modeled on the low-thoracic vertebral region (T10-T12) using percutaneous triple-lead configurations, with the center lead on the spinal cord midline. The triple leads were oriented both aligned and staggered. In the staggered configuration, the anodes were offset either caudally (caudally staggered) or rostrally (rostrally staggered) with respect to the midline cathode. The transverse tripolar field steering with the aligned and staggered configurations enabled the estimation of dorsal column fiber thresholds (IDC) and dorsal root fiber thresholds (IDR) at various anodal current ratios. IDC and IDR were considerably higher for the aligned transverse tripoles as compared to the staggered transverse tripoles. The aligned transverse tripoles facilitated deeper penetration into the medial dorsal columns (DCs). The staggered transverse tripoles always enabled broad and bilateral DC activation, at the expense of mediolateral steerability. The largest DC recruited area was obtained with the rostrally staggered transverse tripole. Transverse tripolar geometries, using percutaneous leads, allow for selective targeting of either medial or lateral DC fibers, if and only if the transverse tripole is aligned. Steering of anodal currents between the lateral leads of the staggered transverse tripoles cannot target medially confined populations of DC fibers in the spinal cord. An aligned transverse tripolar configuration is strongly recommended, because of its ability to provide more post-operative flexibility than other configurations.

  9. Olfactory recognition memory is disrupted in young mice with chronic low-level lead exposure

    PubMed Central

    Flores-Montoya, Mayra Gisel; Alvarez, Juan Manuel; Sobin, Christina

    2015-01-01

    Chronic developmental lead exposure yielding very low blood lead burden is an unresolved child public health problem. Few studies have attempted to model neurobehavioral changes in young animals following very low level exposure, and studies are needed to identify tests that are sensitive to the neurobehavioral changes that may occur. Mechanisms of action are not yet known however results have suggested that hippocampus/dentate gyrus may be uniquely vulnerable to early chronic low-level lead exposure. This study examined the sensitivity of a novel odor recognition task to differences in pre-adolescent C57BL/6J mice chronically exposed from birth to PND 28, to 0 ppm (control), 30 ppm (low-dose), or 330 ppm (higher-dose) lead acetate (N = 33). Blood lead levels (BLLs) determined by ICP-MS ranged from 0.02 to 20.31 µg/dL. Generalized linear mixed model analyses with litter as a random effect showed a significant interaction of BLL × sex. As BLLs increased olfactory recognition memory decreased in males. Among females, non-linear effects were observed at lower but not higher levels of lead exposure. The novel odor detection task is sensitive to effects associated with early chronic low-level lead exposure in young C57BL/6J mice. PMID:25936521

  10. The effect of age of exposure on lead-induced testicular toxicity.

    PubMed

    Sokol, R Z; Berman, N

    1991-01-01

    The present study was designed to assess the significance of age of exposure on the expression of lead toxicity on the male gonad. Male Wistar rats, age 42 days, 52 days and 70 days were treated with lead acetate in their water for 30 days prior to sacrifice. The lead treated groups in all cases had blood lead values significantly greater than control animals. Blood lead levels in control animal groups were less than 7 micrograms/dl. Serum testosterone and sperm concentration and production rate were significantly suppressed in those animals that were exposed to lead acetate starting at age 52 days and 70 days, but not 42 days. These data indicate that prepubertal rats may be less sensitive to the toxic effects of lead than are rats whose exposure begins after puberty has been initiated. PMID:1949051

  11. Failure of EPA`s IEUBK model to identify children at risk from lead exposure

    SciTech Connect

    Coomes, R.M.

    1996-12-31

    Modeled blood lead concentrations derived from EPA`s Integrated Exposure Uptake Biokinetic Model LEAD99 (Model) were compared to measured blood lead concentrations for two populations of children living in Colorado mining communities. The study areas were Clear Creek and California Gulch. Both studies presented paired blood lead level measurements and environmental media lead concentrations. The data for this paper were obtained from the Colorado Department of Health and publicly-available submissions made to EPA Region VIII. EPA has used the Model to identify soil lead concentrations that are protective of individual children.

  12. An ecological risk assessment of lead shot exposure in upland game birds and raptors

    SciTech Connect

    Kendall, R.I.; Lacher, T.E. Jr.; Bunck, C.

    1995-12-31

    There is concern about exposure of birds in terrestrial ecosystems to spent lead shot. Upland birds, particularly mourning doves, ingest spent lead shot; raptors ingest lead shot by consuming wounded game. Mortality, neurological dysfunction, immune suppression and reproductive impairment are effects of exposure to lead. The authors conducted an ecological risk assessment (using the new USEPA Ecological Risk Assessment Paradigm) on the impact of lead shot exposure in upland birds. Large amounts of lead shot are released into the environment each year from shooting and hunting. Doves collected from fields cultivated to attract mourning doves for hunting contain ingested spent lead shot. This might underestimate risk because doves ingesting shot may experience lead toxicosis and not be collected by hunters. Because lead can cause both acute and chronic toxicity if ingested and there is evidence of widespread liberation of lead shot in terrestrial ecosystems, concern for impacts on upland game birds and raptors is warranted. Although this ecological risk assessment does not clearly define a significant risk of upland game birds to lead shot, there is little evidence to rebut the presumption of risk. This issue merits continued scrutiny to protect upland game bird and raptor resources.

  13. Gender differences in blood lead and hemoglobin levels in Andean adults with chronic lead exposure.

    PubMed

    Counter, S A; Buchanan, L H; Ortega, F

    2001-01-01

    A field study of the prevalence of lead (Pb) intoxication was conducted in 158 adults (67 men and 91 women) living at 2,500-2,800 meters in Ecuadorian Andean villages with high Pb contamination from local small-scale Pb-glazing cottage industries. Venous blood samples showed mean blood lead (PbB) levels of 34.5 microg/dL (SD 22.2) for men and 27.0 microg/dL (SD 18.4) for women; this difference was significant (t-test, p = 0.022; Mann-Whitney U, p = 0.044). An ANOVA showed no significant main effect for gender (F = 0.118, p = 0.782) or age (F = 2.479, p = 0.117), and no significant gender-by-age interaction (F = 0.273, p = 0.602). In the Pb-glazing study group, 39% of the men had PbB levels > or = 40 microg/dL, while 41% of the women had PbB levels > or = 30 microg/dL (the WHO health-based biological limits). A reference group of 39 adults (24 men and 15 women) had a mean PbB level of 5.9 microg/dL (SD 2.8; range: 1.8-16.8), significantly different from that of the 158 subjects in the study group (t-test, p < 0.0001). The difference in mean PbB levels of men (6.8 microg/dL) and women (4.7 microg/dL) in the reference group was significant (t-test, p = 0.026; Mann-Whitney U, p = 0.019). The mean altitude-corrected hemoglobin levels in the study group were lower than normal, 11.3 g/dL for men and 10.9 g/dL for women. PMID:11373041

  14. Sex-based differences in gene expression in hippocampus following postnatal lead exposure

    SciTech Connect

    Schneider, J.S. Anderson, D.W.; Sonnenahalli, H.; Vadigepalli, R.

    2011-10-15

    The influence of sex as an effect modifier of childhood lead poisoning has received little systematic attention. Considering the paucity of information available concerning the interactive effects of lead and sex on the brain, the current study examined the interactive effects of lead and sex on gene expression patterns in the hippocampus, a structure involved in learning and memory. Male or female rats were fed either 1500 ppm lead-containing chow or control chow for 30 days beginning at weaning.Blood lead levels were 26.7 {+-} 2.1 {mu}g/dl and 27.1 {+-} 1.7 {mu}g/dl for females and males, respectively. The expression of 175 unique genes was differentially regulated between control male and female rats. A total of 167 unique genes were differentially expressed in response to lead in either males or females. Lead exposure had a significant effect without a significant difference between male and female responses in 77 of these genes. In another set of 71 genes, there were significant differences in male vs. female response. A third set of 30 genes was differentially expressed in opposite directions in males vs. females, with the majority of genes expressed at a lower level in females than in males. Highly differentially expressed genes in males and females following lead exposure were associated with diverse biological pathways and functions. These results show that a brief exposure to lead produced significant changes in expression of a variety of genes in the hippocampus and that the response of the brain to a given lead exposure may vary depending on sex. - Highlights: > Postnatal lead exposure has a significant effect on hippocampal gene expression patterns. > At least one set of genes was affected in opposite directions in males and females. > Differentially expressed genes were associated with diverse biological pathways.

  15. Effects of chronic exposure to sublethal concentrations of lead acetate on heme synthesis and immune function in red-tailed hawks.

    PubMed

    Redig, P T; Lawler, E M; Schwartz, S; Dunnette, J L; Stephenson, B; Duke, G E

    1991-07-01

    Red-tailed hawks were exposed to sublethal levels of lead acetate for periods of 3 or 11 weeks. Alterations in the heme biosynthetic pathway were demonstrated after the first week of exposure to 0.82 mg lead per kilogram body weight per day. Activity of erythrocyte porphobilinogen synthase (aminolevulinic acid dehydratase) was depressed significantly and did not return to normal levels until 5 weeks after the termination of lead treatments. A rapid and relatively brief increase in erythrocyte free protoporphyrin and a slower but more prolonged increase in its zinc complex were also demonstrated with exposure to this dose of lead for 3 weeks. Less substantial decreases in hematocrit and hemoglobin levels occurred but only in the longer experiment with exposure to higher lead levels. Short term, low level lead exposure did not effect immune function significantly in the hawks, as measured by antibody titers to foreign red blood cells or by the mitogenic stimulation of T-lymphocytes. Increased lead exposure produced a significant decrease in the mitogenic response but had no effect on antibody titers. PMID:1898120

  16. Lead exposure affects health indices in free-ranging ducks in Argentina.

    PubMed

    Ferreyra, Hebe; Beldomenico, Pablo M; Marchese, Krysten; Romano, Marcelo; Caselli, Andrea; Correa, Ana I; Uhart, Marcela

    2015-05-01

    Numerous experiments under controlled conditions and extensive investigation of waterfowl die-offs have demonstrated that exposure to lead from spent gunshot is highly detrimental to the health of waterfowl. However, few studies have focused on examining the more subtle sub-lethal effects of lead toxicity on ducks in non-experimental settings. In our study, the health of ducks exposed to varying amounts of lead under natural conditions was assessed by correlating individual lead exposure with relevant indices of health. Based on hunter-killed wild ducks in Argentina, we measured spleen mass, body condition, examined bone marrow smears, and determined Ca and P in bone tissue. In free-ranging live-trapped ducks we determined basic hematology and aminolevulinic acid dehydratase activity. Using multivariate analyses, we found that, when controlling for the potential confounding effect of site type, year, duck species, body mass and age, lead levels in the liver were negatively associated with body condition and spleen mass. Spleen mass was also lower in ducks with higher lead levels in their bones. In live ducks, high blood lead levels were associated with low packed cell volume and red cell morphologic abnormalities. These findings suggest that, despite the lack of recorded lead-induced mortality in the region, lead exposure results in less conspicuous but still significant impacts on the health of ducks, which could have serious implications for their conservation. Moreover, this evidence further supports the need for urgently banning lead shot in the region. PMID:25634770

  17. Response of cardiac autonomic modulation after a single exposure to musical auditory stimulation.

    PubMed

    Ferreira, Lucas L; Vanderlei, Luiz Carlos M; Guida, Heraldo L; de Abreu, Luiz Carlos; Garner, David M; Vanderlei, Franciele M; Ferreira, Celso; Valenti, Vitor E

    2015-01-01

    The acute effects after exposure to different styles of music on cardiac autonomic modulation assessed through heart rate variability (HRV) analysis have not yet been well elucidated. We aimed to investigate the recovery response of cardiac autonomic modulation in women after exposure to musical auditory stimulation of different styles. The study was conducted on 30 healthy women aged between 18 years and 30 years. We did not include subjects having previous experience with musical instruments and those who had an affinity for music styles. The volunteers remained at rest for 10 min and were exposed to classical baroque (64-84 dB) and heavy metal (75-84 dB) music for 10 min, and their HRV was evaluated for 30 min after music cessation. We analyzed the following HRV indices: Standard deviation of normal-to-normal (SDNN) intervals, root mean square of successive differences (RMSSD), percentage of normal-to-normal 50 (pNN50), low frequency (LF), high frequency (HF), and LF/HF ratio. SDNN, LF in absolute units (ms 2 ) and normalized (nu), and LF/HF ratio increased while HF index (nu) decreased after exposure to classical baroque music. Regarding the heavy metal music style, it was observed that there were increases in SDNN, RMSSD, pNN50, and LF (ms 2 ) after the musical stimulation. In conclusion, the recovery response of cardiac autonomic modulation after exposure to auditory stimulation with music featured an increased global activity of both systems for the two musical styles, with a cardiac sympathetic modulation for classical baroque music and a cardiac vagal tone for the heavy metal style. PMID:25774614

  18. Response of cardiac autonomic modulation after a single exposure to musical auditory stimulation

    PubMed Central

    Ferreira, Lucas L.; Vanderlei, Luiz Carlos M.; Guida, Heraldo L.; de Abreu, Luiz Carlos; Garner, David M.; Vanderlei, Franciele M.; Ferreira, Celso; Valenti, Vitor E.

    2015-01-01

    The acute effects after exposure to different styles of music on cardiac autonomic modulation assessed through heart rate variability (HRV) analysis have not yet been well elucidated. We aimed to investigate the recovery response of cardiac autonomic modulation in women after exposure to musical auditory stimulation of different styles. The study was conducted on 30 healthy women aged between 18 years and 30 years. We did not include subjects having previous experience with musical instruments and those who had an affinity for music styles. The volunteers remained at rest for 10 min and were exposed to classical baroque (64-84 dB) and heavy metal (75-84 dB) music for 10 min, and their HRV was evaluated for 30 min after music cessation. We analyzed the following HRV indices: Standard deviation of normal-to-normal (SDNN) intervals, root mean square of successive differences (RMSSD), percentage of normal-to-normal 50 (pNN50), low frequency (LF), high frequency (HF), and LF/HF ratio. SDNN, LF in absolute units (ms2) and normalized (nu), and LF/HF ratio increased while HF index (nu) decreased after exposure to classical baroque music. Regarding the heavy metal music style, it was observed that there were increases in SDNN, RMSSD, pNN50, and LF (ms2) after the musical stimulation. In conclusion, the recovery response of cardiac autonomic modulation after exposure to auditory stimulation with music featured an increased global activity of both systems for the two musical styles, with a cardiac sympathetic modulation for classical baroque music and a cardiac vagal tone for the heavy metal style. PMID:25774614

  19. [ALAD polymorphism and indicators of dose and effects of occupational exposure to inorganic lead].

    PubMed

    De Palma, G; Scotti, E; Mozzoni, P; Alinovi, R; Apostoli, P; Neri, G; Soleo, L; Cassano, F; Carta, P; Murgia, N; Muzi, G; Muttil, A

    2005-01-01

    The delta-aminolevulinate dehydrase (ALAD) genetic polymorphism was investigated along with biomarkers of lead exposure and effect on 333 male workers, occupationally exposed to lead, with blood lead levels (PbB) higher than 100 microg/l. ALAD genotype frequencies were distributed as expected among Caucasians. Workers bearing at least one ALAD-2 allele showed PbB values slightly higher than those from ALAD-1-1 subjects, who also exhibited higher urinary delta-aminolevulinic acid (ALAU) and blood zinc protoporphyrin (ZPP) levels. The plasmatic lead (PbP)/PbB ratio was similar in both groups. Exposure and effect biomarkers were significantly each other correlated among ALAD-1-1 subjects only, who showed also a significant inverse relationship between ALAD activity and ZPP values. Results confirm previous studies, supporting the hypothesis that ALAD polymorphism may interfere with toxico-kinetic and toxico-dynamic parameters of occupational exposure to Pb. PMID:15915653

  20. Lead exposure in bald eagles from big game hunting, the continental implications and successful mitigation efforts.

    PubMed

    Bedrosian, Bryan; Craighead, Derek; Crandall, Ross

    2012-01-01

    Studies suggest hunter discarded viscera of big game animals (i.e., offal) is a source of lead available to scavengers. We investigated the incidence of lead exposure in bald eagles in Wyoming during the big game hunting season, the influx of eagles into our study area during the hunt, the geographic origins of eagles exposed to lead, and the efficacy of using non-lead rifle ammunition to reduce lead in eagles. We tested 81 blood samples from bald eagles before, during and after the big game hunting seasons in 2005-2010, excluding 2008, and found eagles had significantly higher lead levels during the hunt. We found 24% of eagles tested had levels indicating at least clinical exposure (>60 ug/dL) during the hunt while no birds did during the non-hunting seasons. We performed driving surveys from 2009-2010 to measure eagle abundance and found evidence to suggest that eagles are attracted to the study area during the hunt. We fitted 10 eagles with satellite transmitters captured during the hunt and all migrated south after the cessation of the hunt. One returned to our study area while the remaining nine traveled north to summer/breed in Canada. The following fall, 80% returned to our study area for the hunting season, indicating that offal provides a seasonal attractant for eagles. We fitted three local breeding eagles with satellite transmitters and none left their breeding territories to feed on offal during the hunt, indicating that lead ingestion may be affecting migrants to a greater degree. During the 2009 and 2010 hunting seasons we provided non-lead rifle ammunition to local hunters and recorded that 24% and 31% of successful hunters used non-lead ammunition, respectively. We found the use of non-lead ammunition significantly reduced lead exposure in eagles, suggesting this is a viable solution to reduce lead exposure in eagles. PMID:23284837

  1. Lead Exposure in Bald Eagles from Big Game Hunting, the Continental Implications and Successful Mitigation Efforts

    PubMed Central

    Bedrosian, Bryan; Craighead, Derek; Crandall, Ross

    2012-01-01

    Studies suggest hunter discarded viscera of big game animals (i.e., offal) is a source of lead available to scavengers. We investigated the incidence of lead exposure in bald eagles in Wyoming during the big game hunting season, the influx of eagles into our study area during the hunt, the geographic origins of eagles exposed to lead, and the efficacy of using non-lead rifle ammunition to reduce lead in eagles. We tested 81 blood samples from bald eagles before, during and after the big game hunting seasons in 2005–2010, excluding 2008, and found eagles had significantly higher lead levels during the hunt. We found 24% of eagles tested had levels indicating at least clinical exposure (>60 ug/dL) during the hunt while no birds did during the non-hunting seasons. We performed driving surveys from 2009–2010 to measure eagle abundance and found evidence to suggest that eagles are attracted to the study area during the hunt. We fitted 10 eagles with satellite transmitters captured during the hunt and all migrated south after the cessation of the hunt. One returned to our study area while the remaining nine traveled north to summer/breed in Canada. The following fall, 80% returned to our study area for the hunting season, indicating that offal provides a seasonal attractant for eagles. We fitted three local breeding eagles with satellite transmitters and none left their breeding territories to feed on offal during the hunt, indicating that lead ingestion may be affecting migrants to a greater degree. During the 2009 and 2010 hunting seasons we provided non-lead rifle ammunition to local hunters and recorded that 24% and 31% of successful hunters used non-lead ammunition, respectively. We found the use of non-lead ammunition significantly reduced lead exposure in eagles, suggesting this is a viable solution to reduce lead exposure in eagles. PMID:23284837

  2. Reducing lead exposure from drinking water: recent history and current status.

    PubMed Central

    Maas, Richard P.; Patch, Steven C.; Morgan, Diane M.; Pandolfo, Tamara J.

    2005-01-01

    This article discusses the issue of lead contamination of drinking water, noting the various regulatory-driven measures that have been adopted in the U.S. since 1986 to address this public health issue. The article summarizes the literature on the dynamics of tap water lead contamination and discusses this widespread source of lead exposure in the context of the latest research evidence. PMID:16134575

  3. Brainstem auditory evoked potentials in children with low level cumulative lead exposure

    PubMed Central

    Alvarenga, Kátia F.; Morata, Thais C.; Lopes, Andréa Cintra; Feniman, Mariza Ribeiro; Corteletti, Lilian Cássia Bórnia Jacob

    2015-01-01

    Introduction Earlier studies have demonstrated an auditory effect of lead exposure in children,but information on the effects of low chronic exposures needs to be further elucidated. Objective To investigate the effect of low chronic exposures of the auditory system in childrenwith a history of low blood lead levels, using an auditory electrophysiological test. Methods Contemporary cross-sectional cohort. Study participants underwent tympanometry, pure tone and speech audiometry, transient evoked otoacoustic emissions, and brainstem auditory evoked potentials, with blood lead monitoring over a period of 35.5 months. The study included 130 children, with ages ranging from 18 months to 14 years, 5 months (mean age 6years, 8 months ± 3 years, 2 months). Results The mean time-integrated cumulative blood lead index was 12 g/dL (SD ± 5.7, range:2.433). All participants had hearing thresholds equal to or below 20 dBHL and normal amplitudes of transient evoked otoacoustic emissions. No association was found between the absolute latencies of waves I, III, and V, the interpeak latencies I---III, III---V, and I---V, and the cumulative lead values. Conclusion No evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area. PMID:25458254

  4. Lead exposure in passerines inhabiting lead-contaminated floodplains in the Coeur d'Alene River Basin, Idaho, USA

    SciTech Connect

    Johnson, G.D.; Kern, J.W.; Strickland, M.D.; McDonald, L.L. ); Audet, D.J.; LeCaptain, L.J. ); Hoffman, D.J. )

    1999-06-01

    Blood collected from song sparrows (Melospiza melodia) and American robins (Turdus migratorius) captured with mist nets in a lead-contaminated (assessment) area and nearby uncontaminated (reference) areas within the Coeur d'Alene Basin in northern Idaho was analyzed for [delta]-aminolevulinic acid dehydratase activity (ALAD) and hematocrit levels, and livers were analyzed for lead. Mean ALAD inhibition in the assessment area was 51% in song sparrows and 75% in American robins. The proportion of the sampled population with ALAD inhibition > 50% was calculated to be 43% for song sparrows and 83% for American robins. Assessment area hematocrit values for song sparrows and American robins were lower than in reference areas; however, differences were not statistically significant. Significantly higher levels of lead (wet weight) were found in livers from song sparrows captured on the assessment area ([bar x] = 1.93 ppm) than on reference areas. Study results indicate that 43% of the song sparrows and 83% of the American robins inhabiting the floodplain along the Coeur d'Alene River in the assessment area are being exposed to lead at levels sufficient to inhibit ALAD by > 50%. Variability in lead exposure indicators was attributed to high variability in environmental lead concentrations in the Coeur d'Alene River Basin.

  5. Relationship between increased blood lead and pregnancy hypertension in women without occupational lead exposure in Tehran, Iran.

    PubMed

    Vigeh, Mohsen; Yokoyama, Kazuhito; Mazaheri, Maria; Beheshti, Sasan; Ghazizadeh, Shirin; Sakai, Tadashi; Morita, Yoko; Kitamura, Fumihiko; Araki, Shunichi

    2004-02-01

    This study was conducted to assess the relationship between blood lead levels and pregnancy-induced hypertension. Participants were 110 pregnant women, of whom 55 were hypertensive, 27 +/- 5.6 yr of age (mean +/- standard deviation) (range = 17-40 yr); the other 55 women were age- and gravidity-matched normotensive controls. Participants were selected on the basis of their medical history and the results of a questionnaire-based interview. Subjects were at gestational ages 37 +/- 2.5 wk (range = 30-41 wk) and were not occupationally exposed to lead. Blood samples were collected within 24 hr after delivery, and blood lead levels were measured. For the hypertensive cases, blood lead levels were 5.7 +/- 2 microg/dl (range = 2.2-12.6 microg/dl [0.27 +/- 0.10 micromol/l; range = 0.11-0.60 micromol/l]), which were significantly higher than those of the control group (i.e., 4.8 +/- 1.9 microg/dl; range = 1.9-10.6 microg/dl [0.23 +/- 0.09 micromol/l; range = 0.09-0.51 micromol/l]). There were no significant differences in blood lead concentrations among hypertensive subjects with proteinuria (n = 30) and those without proteinuria (n = 25). Results of this study indicated that low-level lead exposure may be a risk factor for pregnancy hypertension. PMID:16075900

  6. Evidence for effects of chronic lead exposure on blood pressure in experimental animals: an overview

    SciTech Connect

    Victery, W.

    1988-06-01

    Information obtained in a number of experimental studies conducted over the last 40 years on the effects of lead on blood pressure is reviewed. Differences in animal species, age at beginning of exposure, level of lead exposure, indices of lead burden, and blood pressure effects on each study are reported. In several of the high-dose experiments, hypertension was observed, but nephrotoxicity of lead may have contributed to its development. Moreover, in other high-dose experiments, no hypertension was observed, and in at least one experiment, the evidence suggested that lead could reduce an elevated blood pressure. In contrast, the lower dose experiments consistently demonstrated a hypertensive effect. Overall, the data suggest a biphasic dose response. Establishment of an appropriate animal model to study blood pressure effects of lead will require careful assessment of dietary interactions with lead, unstressed blood pressure monitoring with standardized techniques, and documentation of biologically effective lead burden. Future research should examine lead exposure at more environmentally appropriate levels in order to determine the validity of associating this pollutant with blood pressure effects in human population.

  7. Profiling Private Water Systems to Identify Patterns of Waterborne Lead Exposure.

    PubMed

    Pieper, Kelsey J; Krometis, Leigh-Anne; Gallagher, Daniel; Benham, Brian; Edwards, Marc

    2015-11-01

    Although extensive literature documents corrosion in municipal water systems, only minimal data is available describing corrosion in private water systems (e.g., wells), which serve as a primary source of drinking water for approximately 47 million Americans. This study developed a profiling technique specifically tailored to evaluate lead release in these systems. When applied in an intensive field study of 15 private systems, three patterns of lead release were documented: no elevated lead or lead elevated in the first draw only (Type I), erratic spikes of particulate lead (Type II), and sustained detectable lead concentrations (Type III). While flushing protocols as short as 15-30 s may be sufficient to reduce lead concentrations below 15 μg/L for Types I and III exposure, flushing may not be an appropriate remediation strategy for Type II exposure. In addition, the sustained detectable lead concentrations observed with Type III exposure likely result from corrosion of components within the well and therefore cannot be reduced with increased flushing. As profiling techniques are labor- and sample-intensive, we discuss recommendations for simpler sampling schemes for initial private system surveys aimed at quantifying lead and protecting public health. PMID:26426487

  8. Benzene and lead exposure assessment among occupational bus drivers in Bangkok traffic.

    PubMed

    Muttamara, S; Leong, Shing Tet; Arayasiri, M

    2004-01-01

    Four environmental and biological monitoring sites were strategically established to evaluate benzene and lead exposure assessment at various traffic zones of Bangkok Metropolitan Region(BMR). Biological measurement of 48 non air-conditioned, male bus drivers was carried to study the relationship between individual exposure levels and exposure biomarkers. The study group was further subdivided into four age groups(16-25, 26-35, 36-45 and 46-55 years old) to monitor the age-related exposure effects. A total of 12 unexposed persons were deliberately chosen as the control group. Measurement of unmetobolized benzene in blood and analysis of urinary tt-Muconic acid urine and urinary creatinine are recommended as biomarkers of benzene exposure. Measurement of lead in blood and urine is also recommended for the biological monitoring of lead exposure. During the monitoring period, benzene and lead levels at Yaowarat Road was C6H6: 42.46 +/- 3.88 microg/m3 , Pb: 0.29 +/- 0.03 microg/m3 and decreased to C6H6: 33.5 +/- 1.35 microg/m3, Pb: 0.13 +/- 0.01 microg/m3 at Phahonyothin Road. Significant difference was established between the nonsmoking exposed group and nonsmoking control group for blood benzene concentrations (P < 0.001, two-tailed, Mann-Whiteney U test). Strong correlations were also found between trans-trans-Muconic acid concentrations in post shift samples and atmospheric benzene concentrations. Similarly, good correlation between all of biomarkers and lead level in air is established from automobile emissions. The analysis revealed that among the occupational population in the urban sites, the driver groups were found to have the highest risk of benzene and lead exposures derived from automobile emission. PMID:14971454

  9. The burden of disease from pediatric lead exposure at hazardous waste sites in 7 Asian countries.

    PubMed

    Caravanos, Jack; Chatham-Stephens, Kevin; Ericson, Bret; Landrigan, Philip J; Fuller, Richard

    2013-01-01

    Identification and systematic assessment of hazardous wastes sites in low and middle-income countries has lagged. Hazardous waste problems are especially severe in lower income Asian countries where environmental regulations are non-existent, nonspecific or poorly enforced. In these countries extensive unregulated industrial development has created waste sites in densely populated urban areas. These sites appear to pose significant risks to public health, and especially to the health of children. To assess potential health risks from chemical contamination at hazardous waste sites in Asia, we assessed 679 sites. A total of 169 sites in 7 countries were classified as contaminated by lead. Eighty-two of these sites contained lead at levels high enough to produce elevated blood lead levels in surrounding populations. To estimate the burden of pediatric lead poisoning associated with exposure to lead in soil and water at these 82 lead-contaminated sites, we used standard toxicokinetic models that relate levels of lead in soil and water to blood lead levels in children. We calculated blood lead levels, and we quantified losses of intelligence (reductions in IQ scores) that were attributable to lead exposure at these sites. We found that 189,725 children in the 7 countries are at risk of diminished intelligence as a consequence of exposure to elevated levels of lead in water and soil at hazardous waste sites. Depending on choice of model, these decrements ranged from 4.94 to 14.96 IQ points. Given the restricted scope of this survey and the conservative estimation procedures employed, this number is almost certainly an underestimate of the full burden of disease. Exposure to toxic chemicals from hazardous waste sites is an important and heretofore insufficiently examined contributor to the Global Burden of Disease. PMID:22999658

  10. Effect of occupational exposure to benzene on phytohaemagglutinin (PHA) stimulated lymphocytes in man.

    PubMed Central

    Yardley-Jones, A; Anderson, D; Jenkinson, P

    1988-01-01

    This study was carried out to investigate the effects of potential low level exposure to benzene on phytohaemagglutinin (PHA) stimulated lymphocytes. Sixty six male workers of a refinery population were studied and compared with 33 control workers in the same refinery who were not known to have been exposed to benzene. The responsiveness of the lymphocyte to PHA as a measure of blastogenesis was measured by the incorporation of radio labelled thymidine by the stimulated lymphocytes in vitro. Questionnaires were used to determine various lifestyle factors such as smoking, drinking, and exposure to ionising radiation. The results showed that there was no difference between the exposed group (mean 28928 + 1524 SE (decays per minute (DPM] as compared with the control group (mean 28304 + 2483 SE DPM). Furthermore, it was not possible to determine any effects attributable to various social factors. There was, however, a suggestion of a decrease in mitogenic response with age in both exposed and control workers that was consistent with other studies. It has been shown that products of benzene metabolism may affect the mitogenic response of lymphocytes in a similar way to known promoting agents. This study was unable to show these effects, probably as a result of the low exposures encountered by the individuals. PMID:3415917

  11. Thyroid toxicity due to subchronic exposure to a complex mixture of 16 organochlorines, lead, and cadmium.

    PubMed

    Wade, Michael G; Parent, Sophie; Finnson, Kenneth W; Foster, Warren; Younglai, Edward; McMahon, Avril; Cyr, Daniel G; Hughes, Claude

    2002-06-01

    The human population in the industrialized world is ubiquitously exposed to complex mixtures of persistent pollutants that contaminate food, water, and air. A large number of these contaminants have been shown to cause significant toxicity to the hypothalamic-pituitary-thyroid (HPT) axis in laboratory animal studies, through a variety of mechanisms, although these effects occur at levels of exposure greatly in excess of common human exposure. While many of the mechanisms of thyroid toxicity of these substances are potentially complementary, little is known of the degree of interaction of common persistent contaminants on responses of the HPT axis. To investigate the potential effects of a complex, environmentally relevant mixture on the HPT axis, sexually mature male rats were administered a mixture of 16 common organochlorines (dichlorodiphenoxytrichloroethane [DDT], p,p'-dichlorodiphenoxydichloroethylene [p,p'-DDE], hexachlorobenzene [HCB], tetrachlorodibenzo-p-dioxin [TCDD], polychlorinated biphenyls [PCBs], methoxychlor, endosulfan, heptachlor, hexachlorocyclohexane, dieldrin, aldrin, mirex, and several chlorinated benzenes, and metal contaminants [lead, cadmium]). The doses of the mixture that were administered were related to minimum risk levels or tolerable daily intakes of these substances, as derived by risk assessment with the 1x, 10x, 100x, and 1000x groups receiving mixture components at doses equivalent to 1x, 10x, 100x, or 1000x the minimum risk level (or tolerable daily intake, reference dose), respectively. After 70 daily treatments by gavage, endpoints related to circulating thyroid hormone (serum thyroxine [T(4)], triiodothyronine [T(3)], thyroid stimulating hormone [TSH], and serum T(3) uptake [T(3)-up]), thyroid gland histomorphology (thyroid follicle cross sectional area, epithelial height, follicle roundness or aspect ratio, colloid/epithelial ratio) and hepatic metabolism of thyroid hormone (UDP-glucuronyl transferase [UGT] and outer

  12. Human lead exposure in a late 19th century mental asylum population.

    PubMed

    Bower, Nathan W; McCants, Sarah A; Custodio, Joseph M; Ketterer, Michael E; Getty, Stephen R; Hoffman, J Michael

    2007-01-01

    Lead isotope ratios and lead (Pb) levels were analyzed in 33 individuals from a forgotten cemetery at the Colorado Mental Health Institute at Pueblo, Colorado dating to 1879-1899. Isotopic ratios from healing bone fractures, cortical bone, and tooth dentine provide information about sources of Pb exposures over a range of time that illuminates individual's life histories and migration patterns. Historical records and Pb production data from the 19th century were used to create a database for interpreting Pb exposures for these African, Hispanic and European Americans. The analysis of these individuals suggests that Pb exposure noticeably impacted the mental health of 5-10% of the asylum patients in this frontier population, a high number by standards today, and that differences exist in the three ancestral groups' exposure histories. PMID:17126382

  13. Economic Costs of Childhood Lead Exposure in Low- and Middle-Income Countries

    PubMed Central

    Trasande, Leonardo

    2013-01-01

    Background: Children’s blood lead levels have declined worldwide, especially after the removal of lead in gasoline. However, significant exposure remains, particularly in low- and middle-income countries. To date, there have been no global estimates of the costs related to lead exposure in children in developing countries. Objective: Our main aim was to estimate the economic costs attributable to childhood lead exposure in low- and middle-income countries. Methods: We developed a regression model to estimate mean blood lead levels in our population of interest, represented by each 1-year cohort of children < 5 years of age. We used an environmentally attributable fraction model to estimate lead-attributable economic costs and limited our analysis to the neurodevelopmental impacts of lead, assessed as decrements in IQ points. Our main outcome was lost lifetime economic productivity due to early childhood exposure. Results: We estimated a total cost of $977 billions of international dollars in low- and middle-income countries, with economic losses equal to $134.7 billion in Africa [4.03% of gross domestic product (GDP)], $142.3 billion in Latin America and the Caribbean (2.04% of GDP), and $699.9 billion in Asia (1.88% of GDP). Our sensitivity analysis indicates a total economic loss in the range of $728.6–1162.5 billion. Conclusions: We estimated that, in low- and middle-income countries, the burden associated with childhood lead exposure amounts to 1.20% of world GDP in 2011. For comparison, in the United States and Europe lead-attributable economic costs have been estimated at $50.9 and $55 billion, respectively, suggesting that the largest burden of lead exposure is now borne by low- and middle-income countries. Citation: Attina TM, Trasande L. 2013. Economic costs of childhood lead exposure in low- and middle-income countries. Environ Health Perspect 121:1097–1102; http://dx.doi.org/10.1289/ehp.1206424 PMID:23797342

  14. Environmental urban lead exposure and blood levels in children of Mexico City

    SciTech Connect

    Romieu, I.; Carreon, T.; Lopez, L.

    1995-11-01

    Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil water, and glazed ceramics were obtained from the participants` households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 {mu}g/dl with a mean of 9.9 {mu}g/dl (SD 5.8 {mu}/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 {mu}g/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used or prepare children`s food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children`s hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics. 18 refs., 5 tabs.

  15. Ultrastructural effects on gill tissues induced in red tilapia Oreochromis sp. by a waterborne lead exposure.

    PubMed

    Aldoghachi, Mohammed A; Azirun, Mohd Sofian; Yusoff, Ismail; Ashraf, Muhammad Aqeel

    2016-09-01

    Experiments on hybrid red tilapia Oreochromis sp. were conducted to assess histopathological effects induced in gill tissues of 96 h exposure to waterborne lead (5.5 mg/L). These tissues were investigated by light and scanning electron microscopy. Results showed that structural design of gill tissues was noticeably disrupted. Major symptoms were changes of epithelial cells, fusion in adjacent secondary lamellae, hypertrophy and hyperplasia of chloride cells and coagulate necrosis in pavement cells with disappearance of its microridges. Electron microscopic X-ray microanalysis of fish gills exposed to sublethal lead revealed that lead accumulated on the surface of the gill lamella. This study confirmed that lead exposure incited a difference of histological impairment in fish, supporting environmental watch over aquatic systems when polluted by lead. PMID:27579014

  16. Developmental lead acetate exposure induces embryonic toxicity and memory deficit in adult zebrafish.

    PubMed

    Chen, Jiangfei; Chen, Yuanhong; Liu, Wei; Bai, Chenglian; Liu, Xuexia; Liu, Kai; Li, Rong; Zhu, Jian-Hong; Huang, Changjiang

    2012-01-01

    Lead is a persistent metal and commonly present in our living environment. The present study was aimed to investigate lead-induced embryonic toxicity, behavioral responses, and adult learning/memory deficit in zebrafish. Lead acetate (PbAc) induced malformations such as uninflated swim bladder, bent spine and yolk-sac edema with an EC₅₀ of 0.29 mg/L at 120 h post fertilization (hpf). Spontaneous movement as characterized by tail bend frequency was significantly altered in zebrafish embryos following exposure to PbAc. Behavior assessment demonstrated that lead exposure changed behavioral responses in zebrafish larvae, as hyperactivity was detected within the first minute of light-to-dark transition in the fish exposed to PbAc from 6 to 96 hpf, and a different dose-dependent change was found in swimming speeds in the dark and in the light at 120 hpf following lead exposure. Learning/memory task assay showed that embryos exposed to PbAc from 6 to 120 hpf developed learning/memory deficit at adulthood as exhibited by a significant decrease in accuracy rate to find the food and a significant increase in finding time. Overall, our results suggested that low dose of developmental lead exposure resulted in embryonic toxicity, behavioral alteration, and adult learning/memory deficit in zebrafish. PMID:22975620

  17. Chronic lead exposure is epidemic in obligate scavenger populations in eastern North America.

    PubMed

    Behmke, Shannon; Fallon, Jesse; Duerr, Adam E; Lehner, Andreas; Buchweitz, John; Katzner, Todd

    2015-06-01

    Lead is a prominent and highly toxic contaminant with important impacts to wildlife. To understand the degree to which wildlife populations are chronically exposed, we quantified lead levels within American black vultures (Coragyps atratus; BLVU) and turkey vultures (Cathartes aura; TUVU), two species that are useful as environmental sentinels in eastern North America. Every individual sampled (n=108) had bone lead levels indicative of chronic exposure to anthropogenic lead (BLVU: x¯=36.99 ± 55.21 mg Pb/kg tissue (±SD); TUVU: x¯=23.02 ± 18.77 mg/kg). Only a few showed evidence of recent lead exposure (BLVU liver: x¯=0.78 ± 0.93 mg/kg; TUVU liver: x¯=0.55 ± 0.34 mg/kg). Isotopic ratios suggested multiple potential sources of lead including ammunition, gasoline, coal-fired power plants, and zinc smelting. Black and turkey vultures range across eastern North America, from Quebec to Florida and individuals may traverse thousands of kilometers annually. The extent to which vultures are exposed suggests that anthropogenic lead permeates eastern North American ecosystems to a previously unrecognized degree. Discovery of an epidemic of chronic lead exposure in such widespread and common species and the failure of soft-tissue sampling to diagnose this pattern has dramatic implications for understanding modern wildlife and human health concerns. PMID:25795925

  18. Delayed blood regeneration in lead exposure: An effect on reserve capacity

    SciTech Connect

    Grandjean, P.; Jensen, B.M.; Sando, S.H.; Jogensen, P.J.; Antonsen, S. )

    1989-10-01

    Twenty-five lead-exposed Danish battery production workers and 25-age-matched controls were examined to evaluate subclinical effects on blood formation. Blood lead levels averaged 2.14 mumol/L and 0.35 mumol/L in the two groups; the lead workers also showed high levels of erythrocyte protoporphyrin, as compared to the controls. Otherwise, the hematological parameters indicated an appropriate iron status and no other deviations. From all subjects, 0.45 L of blood was bled as part of a normal blood donation. Five and 11 days later, reticulocyte counts were significantly higher in the control group than in the lead-exposed workers. On day 15, the lead workers showed a significant delay in blood regeneration, as evidenced by lower hemoglobin concentration, and erythrocyte and reticulocyte counts. The lead exposure in the present study was within legal limits, and lead-induced anemia would be expected only at much higher exposure levels. Thus, despite the normal hematological findings in the initial examination, the lead exposure caused a decreased reserve capacity for blood formation, and this effect became evident only after the blood loss.

  19. Lead poisoning from art restoration and pottery work: unusual exposure source and household risk.

    PubMed

    Fischbein, A; Wallace, J; Sassa, S; Kappas, A; Butts, G; Rohl, A; Kaul, B

    1992-01-01

    Two cases of lead poisoning following exposures in the arts and crafts environment are presented. The first illustrates the impact of an unusual exposure source experienced by a female art conservator while restoring an antique Peruvian tapestry from the Chancay Period (A.D. 1000-1500). The second demonstrates the extension to the artist's family members of a lead hazard associated with pottery work. Noted were a wide spectrum of clinical and biochemical abnormalities, ranging from severe neurological and gastrointestinal symptoms to subtle alterations in the biosynthetic pathway of heme. Marked elevation of the blood lead level (up to 130 mcg/100 mL) was found in the most severe case of lead poisoning. The cases illustrate the need for industrial hygiene measures in this type of work in order to prevent lead intoxication, both in the adult artist and children in the household. However, in some instances of increased lead absorption in persons with lead-related hobbies, sources other than those associated with arts and crafts should be investigated. This alternative is illustrated by a third case, in which firearms training was the more likely source of excessive exposure. Multiple occupational factors must occasionally be considered in evaluating increased lead absorption. PMID:1740771

  20. Pre- and postnatal lead exposure and behavior problems in school-aged children

    SciTech Connect

    Bellinger, D.; Leviton, A.; Allred, E.; Rabinowitz, M. )

    1994-07-01

    The association between early lead exposure and later problem behaviors was evaluated prospectively in a cohort of 8-year-old children born during a 12-month period at one hospital. Lead levels in umbilical cord blood ([bar X] = 6.8 [mu]g/dl, SD = 3.1) and the dentin of a shed deciduous tooth ([bar X] = 3.4 [mu]g/g, SD = 2.4) provided measures of prenatal and postnatal exposure, respectively. Ratings on the Teacher Report Form of the Child Behavior Profile provided information about children's problem behaviors. Cord blood lead level was not associated with the overall prevalence or nature of problem behaviors. In both crude and adjusted analyses, tooth lead level was significantly associated with total problem behavior scores (approximately 2 points in T score per log unit increase in tooth lead). Significant tooth lead-associated increases in both internalizing and externalizing scores were also observed (approximately 1.5 points in T score per log unit increase). Weaker associations were noted between tooth lead level and the prevalence of [open quotes]extreme[close quotes] problem behavior scores. The extent to which these associations reflect residual confounding is uncertain. These data suggest, however, that social and emotional dysfunctions are correlates and may be expressions of increased lead exposure. 64 refs., 2 figs., 9 tabs.

  1. E-Waste Informal Recycling: An Emerging Source of Lead Exposure in South America

    PubMed Central

    Pascale, Antonio; Sosa, Adriana; Bares, Cristina; Battocletti, Alejandra; Moll, María José; Pose, Darío; Laborde, Amalia; González, Hugo; Feola, Gabriella

    2016-01-01

    BACKGROUND Primitive electronic waste (e-waste) recycling creates exposures to several hazardous substances including lead. In Uruguay, primitive recycling procedures are a significant source of lead exposure. OBJECTIVES The aim of this study was to examine lead exposure in blood lead levels (BLLs) in low-income children exposed to lead through burning cables. METHODS A sample of children and adolescents exposed to lead through burning cable activities were assessed at the Department of Toxicology in Montevideo, Uruguay, between 2010 and 2014. Soil lead levels of residences were taken shortly after their assessment. FINDINGS The final sample included 69 children and adolescents (mean age 7.89 years). More than 66% of participants had an additional source of lead exposure—manual gathering of metals—and <5% were exposed to lead through landfills or paint. Average BLLs at first consultation were 9.19 ug/dL and lower at the second measurement (5.86 μg/dL). Data from soil lead levels ranged from 650 to 19,000 mg of lead/kg of soil. The interventions conducted after the assessment included family education in the clinic and at home, indoor and outdoor remediation. We found a decrease in BLLs of 6.96 μg/dL. Older children had lower BLLs (r = −0.24; P =0.05). Statistical analyses also showed that children living in areas with higher soil lead levels had significantly higher BLLs (r = 0.50; P < 0.01). Additionally, we found greater BLLs from burning cable activities when children had been exposed to lead-based paint (r = 0.23; P < 0.1). CONCLUSION Among children exposed to e-waste recycling, the most common additional source of lead exposure was the manual gathering of metals. The average BLL among children and adolescents in this study is higher than the BLLs currently suggested in medical intervention. Future research should focus on exploring effective interventions to reduce lead exposure among this vulnerable group. PMID:27325077

  2. Perinatal taurine exposure programs patterns of autonomic nerve activity responses to tooth pulp stimulation in adult male rats

    PubMed Central

    Khimsuksri, Sawita; Wyss, J. Michael; Thaeomor, Atcharaporn; Paphangkorakit, Jarin; Jirakulsomchok, Dusit; Roysommuti, Sanya

    2016-01-01

    Perinatal taurine excess or deficit influences adult health and disease, especially relative to the autonomic nervous system. This study tests the hypothesis that perinatal taurine exposure influences adult autonomic nervous system control of arterial pressure in response to acute electrical tooth pulp stimulation. Female Sprague-Dawley rats were fed normal rat chow with 3% β-alanine (taurine depletion, TD), 3% taurine (taurine supplementation, TS) or water alone (control, C) from conception to weaning. Their male offspring were fed normal rat chow and tap water throughout the experiment. At 8–10 weeks of age, blood chemistry, arterial pressure, heart rate and renal sympathetic nerve activity were measured in anesthetized rats. Age, body weight, mean arterial pressure, heart rate, plasma electrolytes, blood urea nitrogen, plasma creatinine and plasma cortisol were not significantly different among the three groups. Before tooth pulp stimulation, low (0.3–0.5 Hz) and high frequency (0.5–4.0 Hz) power spectral densities of arterial pressure were not significantly different among groups, while the power spectral densities of renal sympathetic nerve activity were significantly decreased in TD compared to control rats. Tooth pulp stimulation did not change arterial pressure, heart rate, renal sympathetic nerve and arterial pressure power spectral densities in the 0.3–4.0 Hz spectrum or renal sympathetic nerve firing rate in any group. In contrast, perinatal taurine imbalance disturbed very low frequency power spectral densities of both arterial pressure and renal sympathetic nerve activity (below 0.1 Hz), both before and after the tooth pulp stimulation. The power densities of TS were most sensitive to ganglionic blockade and central adrenergic inhibition, while those of TD were sensitive to both central and peripheral adrenergic inhibition. The present data indicate that perinatal taurine imbalance can lead to aberrant autonomic nervous system responses in

  3. Stimulation of estrous behavior in grazing female goats by continuous or discontinuous exposure to males.

    PubMed

    Rivas-Muñoz, R; Fitz-Rodríguez, G; Poindron, P; Malpaux, B; Delgadillo, J A

    2007-05-01

    Two experiments were conducted during the anestrous period to determine: (1) whether males rendered sexually active by exposure to artificial long days stimulate estrous activity of female goats under grazed conditions (Exp. 1); and (2) whether continuous presence of the buck is necessary to stimulate this estrous activity (Exp. 2). In Exp. 1, 2 groups of females (n = 20/group), one in confinement and another under grazing conditions, were exposed to 4 bucks subjected to natural photoperiod (2 males/group). Two other groups of females (n = 20/group), in confinement or grazing, were exposed to 4 males treated with artificial long days (2 males/group). All groups were exposed to males for 15 d. The percentage of does detected in estrus during these 15 d was greater (P < 0.001) in the 2 groups exposed to males sexually prepared by long days (confined, 95%; grazed, 90%) than in groups exposed to males in natural photoperiod (confined, 15%; grazed, 45%). Does in Exp. 2 were allowed to graze and were exposed continuously (n = 26) or discontinuously (from 1700 to 0900; n = 26) for 18 d to males that had been stimulated to enter the breeding season by exposure to long days. The proportion of does that displayed estrous behavior in 18 d did not differ (P = 0.55) between groups (96.2 and 92.3% for continuous and discontinuous groups, respectively). The results indicate that anestrous goats managed under grazing conditions can be stimulated to express estrus by joining with males previously exposed to artificial long days. Continuous presence of the male is not necessary for this male effect. PMID:17085732

  4. Lead exposure of waterfowl ingesting Coeur d?Alene River Basin sediments

    USGS Publications Warehouse

    Beyer, W.N.; Audet, D.J.; Morton, Alexandra; Campbell, J.K.; LeCaptain, L.

    1998-01-01

    Feces from tundra swans (Cygnus columbianus [Ord]), Canada geese (Branta canadensis [L.]) and mallards (Anas platyrhynchos [L.]) were collected from the Coeur d?Alene River Basin and two reference areas to estimate exposure to lead from mining activities and to relate that exposure to the ingestion of contaminated sediments. The average acid-insoluble ash content of the feces, a measure of sediment, was 18% for Canada geese and tundra swans, and 12% for ducks. The 18% value corresponded to an estimated 9% sediment ingestion rate (dry weight). The 90th percentile for acid-insoluble ash in feces of tundra swans corresponds to an estimated 22% sediment in the diet. The average lead concentration (dry weight) of tundra swan feces from all Coeur d?Alene River Basin wetlands sampled was 880 mg/kg, compared to 2.1 mg kg1 from reference wetlands. The 90th percentile of lead in tundra swan feces from the Coeur d?Alene River Basin sites was 2700 mg kg1. Fecal lead concentrations of tundra swans from Harrison Slough, the wetland studied in most detail, were correlated (Spearman?s rho = 0.74, p < 0.05) with the acid-insoluble ash content of the feces. The very low lead concentrations in feces having low acid-insoluble ash contents established that the sediment was the primary source of the lead ingested by waterfowl. Sediment lead concentrations at 11 wetland sites were closely correlated (r = 0.91, p < 0.05) with average fecal lead concentrations for all waterfowl, corrected for the average percent acid-insoluble ash in the feces. The regression equation describing this relation, along with estimates of sediment ingestion, provides a straight-forward means of estimating the current exposure of waterfowl to lead and of predicting the potential exposure of waterfowl to lead under plans to clean up the contaminated sites.

  5. Sex-Based Differences in Gene Expression in Hippocampus Following Postnatal Lead Exposure

    PubMed Central

    Schneider, J.S.; Anderson, D.W.; Sonnenahalli, H.; Vadigepalli, R.

    2011-01-01

    The influence of sex as an effect modifier of childhood lead poisoning has received little systematic attention. Considering the paucity of information available concerning the interactive effects of lead and sex on the brain, the current study examined the interactive effects of lead and sex on gene expression patterns in the hippocampus, a structure involved in learning and memory. Male or female rats were fed either 1500 ppm lead-containing chow or control chow for 30 days beginning at weaning. Blood lead levels were 26.7 ± 2.1 μg/dl and 27.1 ± 1.7 μg/dl for females and males, respectively. The expression of 175 unique genes was differentially regulated between control male and female rats. A total of 167 unique genes were differentially expressed in response to lead in either males or females. Lead exposure had a significant effect without a significant difference between male and female responses in 77 of these genes. In another set of 71 genes, there were significant differences in male vs. female response. A third set of 30 genes was differentially expressed in opposite directions in males vs. females, with the majority of genes expressed at a lower level in females than in males. Highly differentially expressed genes in males and females following lead exposure were associated with diverse biological pathways and functions. These results show that a brief exposure to lead produced significant changes in expression a variety of genes in the hippocampus and that the response of the brain to a given lead exposure may vary depending on sex. PMID:21864555

  6. Lead, arsenic and manganese metal mixture exposures: focus on biomarkers of effect

    PubMed Central

    Andrade, VL; Mateus, ML; Batoréu, MC; Aschner, M; Marreilha dos Santos, AP

    2015-01-01

    Summary The increasing exposure of human populations to excessive levels of metals continues to represent a matter of public health concern. Several biomarkers have been studied and proposed for the detection of adverse health effects induced by lead (Pb), arsenic (As) and manganese (Mn); however, these studies have relied on exposures to each single metal, which fails to replicate real-life exposure scenarios. These 3 metals are commonly detected in different environmental, occupational and food contexts and they share common neurotoxic effects, which are progressive and once clinically apparent may be irreversible. Thus, chronic exposure to low levels of a mixture of these metals represents an additive risk of toxicity. Building upon their shared mechanisms of toxicity, such as oxidative stress, interference with neurotransmitters and effects on hematopoietic system, we address putative biomarkers, which may be assist in assessing onset of neurological diseases associated with exposure to this metal mixture. PMID:25693681

  7. An integrated exposure/pharmacokinetic based approach to the assessment of complex exposures. Lead: a case study

    SciTech Connect

    DeRosa, C.T.; Choudhury, H.; Peirano, W.B. )

    1991-07-01

    A problem in evaluating the hazard represented by an environmental toxicant is that exposures can occur via multiple media such as water, land, and air. Lead is one of the toxicants of concern that has been associated with adverse effects on heme metabolism, serum vitamin D levels, and the mental and physical development of infants and children exposed at very low environmental levels. Effects of lead on development are particularly disturbing in that the consequences of early delays or deficits in physical or mental development may have long-term consequences over the lifetime of affected individuals. Experimental and epidemiologic studies have indicated that blood lead levels in the range of 10-15 micrograms/dl, or possibly lower, are likely to produce subclinical toxicity. Since a discernible threshold has not been demonstrated, it is prudent to preclude development of a Reference Dose (RfD) for lead. As an alternate, the U.S. Environmental Protection Agency (U.S. EPA) has developed the uptake/biokinetic lead model that provides a means for evaluating the relative contribution of various media to establishing blood lead levels in children. This approach will allow for the identification of site- and situation-specific abatement strategies based on projected blood lead levels in vulnerable human populations exposed to lead in air, diet, water, soil/dust, and paint; thus making it possible to evaluate regulatory decisions concerning each medium on blood levels and potential health effects.35 references.

  8. Preimplantation Exposure to Bisphenol A and Triclosan May Lead to Implantation Failure in Humans

    PubMed Central

    Yuan, Mu; Bai, Ming-Zhu; Huang, Xu-Feng; Zhang, Yue; Liu, Jing; Hu, Min-Hao; Zheng, Wei-Qian; Jin, Fan

    2015-01-01

    Endocrine disrupting chemicals (EDCs) are chemicals that have the capacity to interfere with normal endocrine systems. Two EDCs, bisphenol A (BPA) and triclosan (TCS), are mass-produced and widespread. They both have estrogenic properties and similar chemical structures and pharmacokinetic features and have been detected in human fluids and tissues. Clinical evidence has suggested a positive association between BPA exposure and implantation failure in IVF patients. Studies in mouse models have suggested that preimplantation exposure to BPA and TCS can lead to implantation failure. This paper reviews the relationship between preimplantation exposure to BPA and TCS and implantation failure and discusses the remaining problems and possible solutions. PMID:26357649

  9. Shaped, lead-loaded acrylic filters for patient exposure reduction and image-quality improvement

    SciTech Connect

    Gray, J.E.; Stears, J.G.; Frank, E.D.

    1983-03-01

    Shaped filters that are constructed of lead-loaded acrylic material for use in patient radiography are discussed. Use of the filters will result in improved overall image quality with significant exposure reduction to the patient (approximately a 2X reduction in breast exposure and a 3X reduction in thyroid gland exposure). Detailed drawings of the shaped filters for scoliosis radiography, cervical spine radiography, and for long film changers in special procedures are provided. The use of the scoliosis filters is detailed and includes phantom and patient radiographs and dose reduction information.

  10. Sex and Rearing Condition Modify the Effects of Perinatal Lead Exposure on Learning and Memory

    PubMed Central

    Anderson, D. W.; Pothakos, K.; Schneider, J.S.

    2012-01-01

    Developmental lead (Pb) exposure is associated with cognitive impairments in humans and rodents alike. In particular, impaired spatial learning and memory, as assessed using the Morris water maze (MWM), has been noted in developmentally Pb –exposed rats. Although sex and rearing environment can influence MWM performance in normal animals, the interactions of sex and rearing environment on the impact of developmental Pb exposure on hippocampal-dependent processes has not been well characterized. The present study examined the effects of perinatal exposure (i.e., gestation through weaning) to different levels of Pb (250, 750 and 1,500 ppm Pb acetate in food) in males and females raised in a non-enriched environment (standard cage with 3 animals and no toys) or an enriched environment (large cage containing a variety of toys that were changed twice weekly). Testing in the MWM began at postnatal day 55. Behavioral outcomes were influenced by sex and rearing environment, with complex interactions with Pb exposure. In non-Pb exposed control animals, beneficial effects of environmental enrichment on spatial learning and memory were observed in males and females, with greater effects in females. Pb exposure in females mitigated at least some of the benefits of enrichment on learning, particularly at the lowest and highest exposure levels. In males, enrichment conferred a modest learning advantage and for the most part, Pb exposure did not affect this. However, in males with the highest Pb exposure, enrichment did help to overcome detrimental effects of Pb on learning. In females, any potential benefit to reference memory contributed by enrichment was muted by exposure to Pb and for the most part, this was not reproduced in males. Thus, there are complex interactions between sex, environment, and Pb exposure on spatial learning and memory. Environmental manipulation is a potential risk modifier of developmental Pb exposure and interacts with other factors including sex

  11. Developmental lead exposure alters gene expression of metabotropic glutamate receptors in rat hippocampal neurons.

    PubMed

    Xu, Jian; Yan, Chong-Huai; Wu, Sheng-Hu; Yu, Xiao-Dan; Yu, Xiao-Gang; Shen, Xiao-Ming

    2007-02-21

    Exposure to lead in utero and in infancy is associated with a risk of impaired cognitive development. Increasing evidence suggests that the family of metabotropic glutamate receptors (mGluRs) plays an important role in synaptic plasticity and memory formation. We determined whether mGluRs subtypes 1, 3, and 7 (mGluR1, mGluR3, and mGluR7) were involved in developmental neurotoxicity due to lead. Embryonic rat hippocampal neurons were cultured for 21 days and exposed to lead chloride beginning on the fourth day of incubation. We investigated levels of mGluR1, mGluR3, and mGluR7 mRNA expression by using quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR) with lead exposure at 10 nM, 1 microM, and 100 microM. Lead exposure in vitro downregulated the expression of mGluR1 mRNA and upregulated the expression of mGluR3 and mGluR7 mRNA in a dose-dependent manner. We speculate that mGluRs may be involved in lead neurotoxicity. Pathways that likely contribute to lead neurotoxicity by means of mGluRs are impairment of long-term potentiation, effects on N-methyl-D-aspartate (NMDA) receptor functions, and depotentiation. PMID:17267122

  12. Cumulative exposure to lead and cognition in persons with Parkinson’s disease

    PubMed Central

    Weuve, Jennifer; Press, Daniel Z.; Grodstein, Francine; Wright, Robert O.; Hu, Howard; Weisskopf, Marc G.

    2012-01-01

    Background Dementia is an important consequence of Parkinson’s disease (PD), with few known modifiable risk factors. Cumulative exposure to lead, at levels experienced in the community, may exacerbate PD-related neural dysfunction, resulting in impaired cognition. Methods Among 101 persons with PD (“cases”) and, separately, 50 persons without PD (“controls”), we evaluated cumulative lead exposure, gauged via tibia and patella bone lead concentrations, in relation to cognitive function, assessed using a telephone battery developed and validated in a separate sample of PD patients. We also assessed the interaction between lead and case-control status. Results After multivariable adjustment, higher tibia bone lead concentration among PD cases was associated with worse performance on all of the individual telephone tests. In particular, tibia lead levels corresponded to significantly worse performance on a telephone analogue of the Mini-Mental State Examination and tests of working memory and attention. Moreover, higher tibia bone lead concentration was associated with significantly worse global composite score encompassing all the cognitive tests (P=0.04). The magnitude of association per standard deviation increment in tibia bone lead level was equivalent to the difference in global scores among controls in our study who were about seven years apart in age. The tibia lead-cognition association was notably stronger within cases than within controls (Pdifference=0.06). Patella bone lead concentration was not consistently associated with performance on the tests. Conclusions These data provide evidence suggesting that cumulative exposure to lead may result in worsened cognition among persons with PD. PMID:23143985

  13. Hemograms for and nutritional condition of migrant bald eagles tested for exposure to lead.

    PubMed

    Miller, M J; Wayland, M E; Bortolotti, G R

    2001-07-01

    Plasma proteins, hematocrit, differential blood counts were examined and nutritional condition was estimated for bald eagles (Haliaeetus leucocephalus) trapped (n = 66) during antumn migration, 1994-95 at Galloway Bay (Saskatchewan, Canada), for the purposes of estimating prevalence of exposure to lead. Sex and age differences in hematocrit and plasma proteins were not observed; however, female eagles exhibited larger median absolute heterophil counts than males. Hematologic values were similar to those previously reported from eagles in captivity. Departures from expected hematological values from a healthy population of eagles were not observed in birds with elevated levels of blood lead (> or =0.200 microg/ml). Similarly, nutritional condition was not related to blood-lead concentrations. Therefore, it appears that lead exposure in this population was below a threshold required to indicate toxicological alteration in the hematological values and index of nutritional condition that we measured. PMID:11504222

  14. Lead Paint Exposure Assessment in High Bays of Johnson Space Center

    NASA Technical Reports Server (NTRS)

    Stanch, Penney; Plaza, Angel; Keprta, Sean

    2008-01-01

    This slide presentation reviews the program to assess the possibility of lead paint exposure in the high bays of some of the Johnson Space Center buildings. Some of the buildings in the Manned Space Flight Center (MSC) were built in 1962 and predate any considerations to reduce lead in paints and coatings. There are many of these older buildings that contain open shops and work areas that have open ceilings, These shops include those that had operations that use leaded gasoline, batteries, and lead based paints. Test were planned to be conducted in three phases: (1) Surface Dust sampling, (2) personal exposure montioring, and (3) Ceiling paint Sampling. The results of the first two phases were reviewed. After considering the results of the first two phases, and the problems associated with the retrieval of samples from high ceilings, it was determined that the evaluation of ceiling coatings would be done on a project by project and in response to a complaint.

  15. Evaluation of the hepatotoxic risk caused by lead acetate via skin exposure using a proteomic approach.

    PubMed

    Fang, Jia-You; Wang, Pei-Wen; Huang, Chun-Hsun; Hung, Yi-Yun; Pan, Tai-Long

    2014-11-01

    Lead compounds exhibit a high degree of cytotoxicity and carcinogenicity. We evaluated the impact of lead acetate on the liver by skin exposure as well as the changes in protein profiles reflecting pathogenic processes. Functional proteomic tools showed that the most meaningful protein changes were involved in protein folding, ER stress, and apoptosis in the presence of an organic lead compound. Treatment with lead acetate also elicits intracellular ROS levels as well as carbonyl modification of chaperone proteins, suggesting that lead might trigger the unfolded protein response due to oxidative stress. Lead application induced ER stress, as indicated by the promotion of GRP78 and by increased expression of the transcription factors ATF6, IRE1α, and PERK. Moreover, upregulation of GRP75 may participate in lead-caused hepatic cytotoxicity while abrogation of GRP75 appears to attenuate the inhibition of cell growth. Our findings demonstrate that accumulation of organic lead in the liver can induce oxidative imbalance and protein impairment that may result in ER stress followed by liver injuries. Hepatic proteome profiles delineate a finer picture of protein networks and metabolic pathways primarily involved in lead-initiated hepatic toxicity via skin exposure. PMID:25210813

  16. Mortality and lead exposure: a retrospective cohort study of Swedish smelter workers.

    PubMed Central

    Gerhardsson, L; Lundström, N G; Nordberg, G; Wall, S

    1986-01-01

    The study is based on the work histories and mortality data for 3832 male workers first employed before 1967 at a copper smelter in northern Sweden and followed up from 1950 to 1981. From the 3832 workers a lead cohort consisting of 437 workers employed for at least three years at sites with considerable lead exposure during 1950-74 was selected. These workers had regularly had blood lead measurements performed since 1950. Based on the cumulative blood lead dose 1950-74 and peak blood lead values, the cohort was subdivided into high mean, low mean, high peak, and low peak groups. Standardised mortality ratios (SMR) were calculated for the six groups using general and local reference populations. The original cohort of 3832 workers showed considerable excess of deaths for total mortality, malignant neoplasms especially lung and stomach cancer, ischaemic heart diseases, and cerebrovascular diseases when compared with the general population. In the lead cohort where the workers had been subjected to a considerable lead exposure only the raised SMR for lung cancer was sustained (SMR = 162; not significant). No significant differences were found between high lead and low lead exposed smelter workers. PMID:3778840

  17. Lead exposure in passerines inhabiting lead-contaminated floodplains in the Coeur d'Alene River Basin, Idaho, USA

    USGS Publications Warehouse

    Johnson, G.D.; Audet, D.J.; Kern, J.W.; LeCaptain, L.J.; Strickland, M.D.; Hoffman, D.J.; McDonald, L.L.

    1999-01-01

    Blood collected from song sparrows (Melospiza melodia) and American robins (Turdus migratorius) captured with mist nets in a lead-contaminated (assessment) area and nearby uncontaminated (reference) areas within the Coeur d'Alene Basin in northern Idaho was analyzed for d-aminolevulinic acid dehydratase activity (ALAD) and hematocrit levels, and livers were analyzed for lead. Mean ALAD inhibition in the assessment area was 51% in song sparrows and 75% in American robins. The proportion of the sampled population with ALAD inhibition >50% was calculated to be 43% for song sparrows and 83% for American robins. Assessment area hematocrit values for song sparrows (0 = 39.9) and American robins (0 = 39.5) were lower than in reference areas (0 = 42.4 for song sparrows and 40.2 for American robins); however, differences were not statistically significant (p > 0.05). Significantly higher levels of lead (wet weight) were found in livers from song sparrows captured on the assessment area (0 = 1.93 ppm) than on reference areas (0 = 0.10 ppm) (p = 0.0079). Study results indicate that 43% (95% confidence interval [CI] = 12.9-77.5%) of the song sparrows and 83% (95% CI = 41.8-99.2%) of the American robins inhabiting the floodplain along the Coeur d'Alene River in the assessment area are being exposed to lead at levels sufficient to inhibit ALAD by > 50%. Variability in lead exposure indicators was attributed to high variability in environmental lead concentrations in the Coeur d'Alene River Basin.

  18. Neonatal lead exposure changes quality of sperm and number of macrophages in testes of BALB/c mice.

    PubMed

    Pace, Beata M; Lawrence, David A; Behr, Melissa J; Parsons, Patrick J; Dias, James A

    2005-06-01

    BALB/c mice were exposed to 0.1 ppm lead acetate in the drinking water from postnatal day (PND) 1 for 6 weeks. Until PND21, lead exposure was from mother's milk; thereafter, it was directly from the drinking water. The blood lead levels were the highest in pups before weaning (59.5+/-0.9 microg/dL) and significantly lower between PND21 and PND42 (20.3+/-4.7 microg/dL). At PND42, lead-exposed male mice were tested for fertility, sperm DNA, and macrophage number. Mating of lead-treated males with non-treated females confirmed the reduction of fertility in the exposed males. Flow cytometric studies of testicular preparations indicated that the sperm count was not different between lead-exposed and control males; however, the lead-treated mice had a significant increase in the number of testicular cells having a < 1n amount of DNA, which coincided with a decrease in the number of testicular cells with a 2n and 4n amount of DNA. The number of testicular macrophages also was decreased in lead-exposed males, which could reflect altered levels of CSF-1 or response to CSF-1, as previously reported [Kowolenko, M., Tracy, L., Lawrence, D.A., 1989. Lead-induced alterations of in vitro bone marrow cell responses to colony stimulating factor-1. J. Leukoc. Biol. 45, 198-206]. Our study showed that exposure to 0.1 ppm of lead during the neonatal and adolescent period is sufficient to reduce fertility in adult male mice; however, it did not affect sperm count on PND42. The presence of an increased number of apoptotic (< 1n amount of DNA) testicular cells may be diagnostic of defective sperm function. Thus, an administered dose of 0.1 ppm via drinking water ingestion by neonatal male BALB/c mice sufficient to produce PbB of 20-60 mg/dL compromised reproductive function in these mice as adults. PMID:15840438

  19. Cumulative Lead Exposure and Age at Menopause in the Nurses’ Health Study Cohort

    PubMed Central

    Eum, Ki-Do; Nie, Linda H.; Hu, Howard; Korrick, Susan A.

    2014-01-01

    Background: Early menopause has been associated with many adverse health outcomes, including increased risk of cardiovascular disease morbidity and mortality. Lead has been found to be adversely associated with female reproductive function, but whether exposures experienced by the general population are associated with altered age at menopause has not been explored. Objective: Our goal was to assess the association between cumulative lead exposure and age at natural menopause. Methods: Self-reported menopausal status and bone lead concentration measured with K-shell X-ray fluorescence—a biomarker of cumulative lead exposure—were obtained from 434 women participants in the Nurses’ Health Study. Results: The mean (± SD) age at natural menopause was 50.8 ± 3.6 years. Higher tibia lead level was associated with younger age at menopause. In adjusted analyses, the average age of menopause for women in the highest tertile of tibia lead was 1.21 years younger (95% CI: –2.08, –0.35) than for women in the lowest tertile (p-trend = 0.006). Although the number of cases was small (n = 23), the odds ratio for early menopause (< 45 years of age) was 5.30 (95% CI: 1.42, 19.78) for women in the highest tertile of tibia lead compared with those in the lowest tertile (p-trend = 0.006). There was no association between patella or blood lead and age at menopause. Conclusions: Our results support an association between low-level cumulative lead exposure and an earlier age at menopause. These data suggest that low-level lead exposure may contribute to menopause-related health outcomes in older women through effects on age at menopause. Citation: Eum KD, Weisskopf MG, Nie LH, Hu H, Korrick SA. 2014. Cumulative lead exposure and age at menopause in the Nurses’ Health Study Cohort. Environ Health Perspect 122:229–234; http://dx.doi.org/10.1289/ehp.1206399 PMID:24398113

  20. Multimedia exposures to arsenic and lead for children near an inactive mine tailings and smelter site.

    PubMed

    Loh, Miranda M; Sugeng, Anastasia; Lothrop, Nathan; Klimecki, Walter; Cox, Melissa; Wilkinson, Sarah T; Lu, Zhenqiang; Beamer, Paloma I

    2016-04-01

    Children living near contaminated mining waste areas may have high exposures to metals from the environment. This study investigates whether exposure to arsenic and lead is higher in children in a community near a legacy mine and smelter site in Arizona compared to children in other parts of the United States and the relationship of that exposure to the site. Arsenic and lead were measured in residential soil, house dust, tap water, urine, and toenail samples from 70 children in 34 households up to 7 miles from the site. Soil and house dust were sieved, digested, and analyzed via ICP-MS. Tap water and urine were analyzed without digestion, while toenails were washed, digested and analyzed. Blood lead was analyzed by an independent, certified laboratory. Spearman correlation coefficients were calculated between each environmental media and urine and toenails for arsenic and lead. Geometric mean arsenic (standard deviation) concentrations for each matrix were: 22.1 (2.59) ppm and 12.4 (2.27)ppm for soil and house dust (<63μm), 5.71 (6.55)ppb for tap water, 14.0 (2.01)μg/L for specific gravity-corrected total urinary arsenic, 0.543 (3.22)ppm for toenails. Soil and vacuumed dust lead concentrations were 16.9 (2.03)ppm and 21.6 (1.90) ppm. The majority of blood lead levels were below the limit of quantification. Arsenic and lead concentrations in soil and house dust decreased with distance from the site. Concentrations in soil, house dust, tap water, along with floor dust loading were significantly associated with toenail and urinary arsenic but not lead. Mixed models showed that soil and tap water best predicted urinary arsenic. In our study, despite being present in mine tailings at similar levels, internal lead exposure was not high, but arsenic exposure was of concern, particularly from soil and tap water. Naturally occurring sources may be an additional important contributor to exposures in certain legacy mining areas. PMID:26803211

  1. Anterior hypothalamic vasopressin modulates the aggression-stimulating effects of adolescent cocaine exposure in Syrian hamsters.

    PubMed

    Jackson, D; Burns, R; Trksak, G; Simeone, B; DeLeon, K R; Connor, D F; Harrison, R J; Melloni, R H

    2005-01-01

    Repeated low-dose cocaine treatment (0.5 mg/kg/day) during adolescence induces offensive aggression in male Syrian hamsters (Mesocricetus auratus). This study examines the hypothesis that adolescent cocaine exposure predisposes hamsters to heightened levels of aggressive behavior by increasing the activity of the anterior hypothalamic-vasopressinergic neural system. In a first experiment, adolescent male hamsters were treated with low-dose cocaine and then scored for offensive aggression in the absence or presence of vasopressin receptor antagonists applied directly to the anterior hypothalamus. Adolescent cocaine-treated hamsters displayed highly escalated offensive aggression that could be reversed by blocking the activity of vasopressin receptors within the anterior hypothalamus. In a second set of experiments, adolescent hamsters were administered low-dose cocaine or vehicle, tested for offensive aggression, and then examined for differences in vasopressin innervation patterns and expression levels in the anterior hypothalamus, as well as the basal- and stimulated-release of vasopressin in this same brain region. Aggressive, adolescent cocaine-treated hamsters showed no differences in vasopressin afferent innervation and/or peptide levels in the anterior hypothalamus compared with non-aggressive, saline-treated littermates. Conversely, significant increases in stimulated, but not basal, vasopressin release were detected from the anterior hypothalamus of aggressive, cocaine-treated animals compared with non-aggressive, saline-treated controls. Together, these data suggest that adolescent cocaine exposure increases aggression by increasing stimulated release of vasopressin in the anterior hypothalamus, providing direct evidence for a causal role of anterior hypothalamic-vasopressin activity in adolescent cocaine-induced offensive aggression. A model for how alterations in anterior hypothalamic-vasopressin neural functioning may facilitate the development of the

  2. Using Behavior Change to Reduce Child Lead Exposure in Resource-Poor Settings: A Formative Study

    ERIC Educational Resources Information Center

    Feit, M. N.; Mathee, A.; Harpham, T.; Barnes, B. R.

    2014-01-01

    The objective of this formative research was to explore the acceptability and feasibility of changing housekeeping behaviors as a low-cost approach that may reduce childhood lead exposure in Johannesburg, South Africa. Using the Trials of Improved Practices (TIPs) methodology, modified housekeeping behaviors were negotiated with participants who…

  3. Ultrasonographic measurement of the femoral cartilage thickness in patients with occupational lead exposure.

    PubMed

    Yıldızgören, Mustafa T; Baki, Ali E; Kara, Murat; Ekiz, Timur; Tiftik, Tülay; Tutkun, Engin; Yılmaz, Hınç; Özçakar, Levent

    2015-01-01

    The objective of the present study is to compare distal femoral cartilage thicknesses of patients with occupational lead exposure with those of healthy subjects by using ultrasonography. A total of 48 male workers (a mean age of 34.8±6.8 years and mean body mass index (BMI) of 25.8±3.1 kg/m(2)) with a likely history of occupational lead exposure and age- and BMI-matched healthy male subjects were enrolled. Demographic and clinical characteristics of the patients, that is, age, weight, height, occupation, estimated duration of lead exposure, and smoking habits were recorded. Femoral cartilage thickness was assessed from the midpoints of right medial condyle (RMC), right lateral condyle (RLC), right intercondylar area (RIA), left medial condyle (LMC), left lateral condyle (LLC), and left intercondylar area (LIA) by using ultrasonography. Although the workers had higher femoral cartilage thickness values at all measurement sites when compared with those of the control subjects, the difference reached statistical significance at RLC (P=0.010), LMC (P=0.001), and LIA (P=0.039). There were no correlations between clinical parameters and cartilage-thickness values of the workers. Subjects with a history of lead exposure had higher femoral cartilage thickness as compared with the healthy subjects. Further studies, including histological evaluations, are awaited to clarify the clinical relevance of this increase in cartilage thickness and to explore the long-term follow-up especially with respect to osteoarthritis development. PMID:25248935

  4. BIOLOGICAL ASSESSMENT OF CONTINUOUS EXPOSURE TO TRITIUM AND LEAD IN THE RAT

    EPA Science Inventory

    In an attempt to contribute information on the effects of simultaneous exposure to two potentially synergistic environmental pollutants the authors have chronically administered tritiated water (HTO) and lead (Pb) to rats. HTO and Pb were selected because they are ubiquitous in t...

  5. Quantile regression in environmental health: Early life lead exposure and end-of-grade exams.

    PubMed

    Magzamen, Sheryl; Amato, Michael S; Imm, Pamela; Havlena, Jeffrey A; Coons, Marjorie J; Anderson, Henry A; Kanarek, Marty S; Moore, Colleen F

    2015-02-01

    Conditional means regression, including ordinary least squares (OLS), provides an incomplete picture of exposure-response relationships particularly if the primary interest resides in the tail ends of the distribution of the outcome. Quantile regression (QR) offers an alternative methodological approach in which the influence of independent covariates on the outcome can be specified at any location along the distribution of the outcome. We implemented QR to examine heterogeneity in the influence of early childhood lead exposure on reading and math standardized fourth grade tests. In children from two urban school districts (n=1,076), lead exposure was associated with an 18.00 point decrease (95% CI: -48.72, -3.32) at the 10th quantile of reading scores, and a 7.50 point decrease (95% CI: -15.58, 2.07) at the 90th quantile. Wald tests indicated significant heterogeneity of the coefficients across the distribution of quantiles. Math scores did not show heterogeneity of coefficients, but there was a significant difference in the lead effect at the 10th (β=-17.00, 95% CI: -32.13, -3.27) versus 90th (β=-4.50, 95% CI: -10.55, 4.50) quantiles. Our results indicate that lead exposure has a greater effect for children in the lower tail of exam scores, a result that is masked by conditional means approaches. PMID:25531815

  6. LONG-TERM EFFECTS OF LEAD EXPOSURE ON THREE GENERATIONS OF BROOK TROUT ('SALVELINUS FONTINALIS')

    EPA Science Inventory

    Exposure of three generations of brook trout (Salvelinus fontinalis) to mean total lead concentrations (0.9-474 microg/l) showed that all second-generation trout exposed to 235 and 474 microg Pb/l and 34% of those exposed to 119 microg Pb/l developed severe spinal deformities (sc...

  7. Epigenetic histone modification regulates developmental lead exposure induced hyperactivity in rats.

    PubMed

    Luo, Man; Xu, Yi; Cai, Rong; Tang, Yuqing; Ge, Meng-Meng; Liu, Zhi-Hua; Xu, Li; Hu, Fan; Ruan, Di-Yun; Wang, Hui-Li

    2014-02-10

    Lead (Pb) exposure was commonly considered as a high environmental risk factor for the development of attention-deficit/hyperactivity disorder (ADHD). However, the molecular basis of this pathological process still remains elusive. In light of the role of epigenetics in modulating the neurological disease and the causative environment, the alterations of histone modifications in the hippocampus of rats exposed by various doses of lead, along with concomitant behavioral deficits, were investigated in this study. According to the free and forced open field test, there showed that in a dosage-dependent manner, lead exposure could result in the increased locomotor activity of rats, that is, hyperactivity: a subtype of ADHD. Western blotting assays revealed that the levels of histone acetylation increased significantly in the hippocampus by chronic lead exposure, while no dramatic changes were detected in terms of expression yields of ADHD-related dopaminergic proteins, indicating that histone acetylation plays essential roles in this toxicant-involved pathogenesis. In addition, the increased level of histone acetylation might be attributed to the enzymatic activity of p300, a typical histone acetyltransferase, as the transcriptional level of p300 was significantly increased upon higher-dose Pb exposure. In summary, this study first discovered the epigenetic mechanism bridging the environmental influence (Pb) and the disease itself (ADHD) in the histone modification level, paving the way for the comprehensive understanding of ADHD's etiology and in further steps, establishing the therapy strategy of this widespread neurological disorder. PMID:24291742

  8. Evaluation of exposure to lead from drinking water in large buildings.

    PubMed

    Deshommes, Elise; Andrews, Robert C; Gagnon, Graham; McCluskey, Tim; McIlwain, Brad; Doré, Evelyne; Nour, Shokoufeh; Prévost, Michèle

    2016-08-01

    Lead results from 78,971 water samples collected in four Canadian provinces from elementary schools, daycares, and other large buildings using regulatory and investigative sampling protocols were analyzed to provide lead concentration distributions. Maximum concentrations reached 13,200 and 3890 μg/L following long and short stagnation periods respectively. High lead levels were persistent in some large buildings, reflected by high median values considering all taps, or specific to a few taps in the building. Simulations using the Integrated Uptake Biokinetic (IEUBK) model and lead concentrations after 30 min of stagnation in the dataset showed that, for most buildings, exposure to lead at the tap does not increase children's blood lead levels (BLLs). However, buildings or taps with extreme concentrations represent a significant health risk to young children attending school or daycare, as the estimated BLL far exceeded the 5 μg/dL threshold. Ingestion of water from specific taps could lead to acute exposure. Finally, for a few taps, the total daily lead intake reached the former World Health Organization (WHO) tolerable level for adults, suggesting potential health risks. PMID:27132198

  9. Lead exposure in battery-factory workers is not associated with anemia.

    PubMed

    Froom, P; Kristal-Boneh, E; Benbassat, J; Ashkanazi, R; Ribak, J

    1999-02-01

    Anemia is a manifestation of lead toxicity. However, there are conflicting reports of its prevalence among lead-exposed workers, and it is uncertain whether they should be monitored by periodic hemoglobin (Hb) examinations. To explore the relationship between Hb and lead exposure, we examined the correlation between Hb, blood lead (PbB), and zinc protoporphyrin (ZPP) levels in 961 blood samples obtained from 94 workers in a lead-acid battery plant in Israel between 1980 and 1993. Blood lead levels exceeded 60 micrograms/dL (2.90 mumol/L) in 105 (14%) of the blood samples. The correlation between PbB and logZPP was 0.594. Hb levels did not correlate with PbB or ZPP. We conclude that (a) periodic Hb determinations are not a useful indicator of lead exposure in Israeli industrial workers; (b) the discrepancies between the reported correlation between PbB and Hb levels remain unexplained and in need of further study; and (c) a finding of anemia in a person with PbB levels of up to 80 micrograms/dL should be considered to be due to lead toxicity only after other causes for anemia have been excluded. PMID:10029957

  10. Effect of the exposure to metal lead on the regenerative ability of Lumbriculus variegatus (Oligochaeta).

    PubMed

    Sardo, Ana Margarida; Pereira, Lourdes; Gerhardt, Almut; Soares, Amadeu M V M

    2011-01-01

    Lumbriculus variegatus is a recommended species for use in sediment toxicity tests and is known to have a remarkable power of segmental regeneration. Here, we tested the effects of a chemical stressor on the regenerative ability of L. variegatus and investigated the potential of regenerative ability as an additional new parameter in standard toxicity tests. The worms were cut into two equal segments, and exposed to various concentrations of lead. Two assays were performed: one with sediment spiked with lead and the other with water spiked with lead. The endpoints were segmental regeneration, survival and behaviour. Regenerative ability was clearly affected by exposure to lead-contaminated sediment and lead-contaminated water. Organisms exposed to lead grew more slowly than those not exposed; worms exposed to contaminated water showed higher mortalities than those exposed to contaminated sediment. Results showed that L. variegatus' regenerative ability, as a developmental test parameter, is more sensitive than mortality. PMID:21787687

  11. Developmental Ethanol Exposure Leads to Dysregulation of Lipid Metabolism and Oxidative Stress in Drosophila

    PubMed Central

    Logan-Garbisch, Theresa; Bortolazzo, Anthony; Luu, Peter; Ford, Audrey; Do, David; Khodabakhshi, Payam; French, Rachael L.

    2014-01-01

    Ethanol exposure during development causes an array of developmental abnormalities, both physiological and behavioral. In mammals, these abnormalities are collectively known as fetal alcohol effects (FAE) or fetal alcohol spectrum disorder (FASD). We have established a Drosophila melanogaster model of FASD and have previously shown that developmental ethanol exposure in flies leads to reduced expression of insulin-like peptides (dILPs) and their receptor. In this work, we link that observation to dysregulation of fatty acid metabolism and lipid accumulation. Further, we show that developmental ethanol exposure in Drosophila causes oxidative stress, that this stress is a primary cause of the developmental lethality and delay associated with ethanol exposure, and, finally, that one of the mechanisms by which ethanol increases oxidative stress is through abnormal fatty acid metabolism. These data suggest a previously uncharacterized mechanism by which ethanol causes the symptoms associated with FASD. PMID:25387828

  12. Developmental ethanol exposure leads to dysregulation of lipid metabolism and oxidative stress in Drosophila.

    PubMed

    Logan-Garbisch, Theresa; Bortolazzo, Anthony; Luu, Peter; Ford, Audrey; Do, David; Khodabakhshi, Payam; French, Rachael L

    2014-01-01

    Ethanol exposure during development causes an array of developmental abnormalities, both physiological and behavioral. In mammals, these abnormalities are collectively known as fetal alcohol effects (FAE) or fetal alcohol spectrum disorder (FASD). We have established a Drosophila melanogaster model of FASD and have previously shown that developmental ethanol exposure in flies leads to reduced expression of insulin-like peptides (dILPs) and their receptor. In this work, we link that observation to dysregulation of fatty acid metabolism and lipid accumulation. Further, we show that developmental ethanol exposure in Drosophila causes oxidative stress, that this stress is a primary cause of the developmental lethality and delay associated with ethanol exposure, and, finally, that one of the mechanisms by which ethanol increases oxidative stress is through abnormal fatty acid metabolism. These data suggest a previously uncharacterized mechanism by which ethanol causes the symptoms associated with FASD. PMID:25387828

  13. Maternal exposure to arsenic, cadmium, lead, and mercury and neural tube defects in offspring

    SciTech Connect

    Brender, Jean D. . E-mail: jdbrender@aol.com; Suarez, Lucina; Felkner, Marilyn; Gilani, Zunera; Stinchcomb, David; Moody, Karen; Henry, Judy; Hendricks, Katherine

    2006-05-15

    Arsenic, cadmium, lead, and mercury are neurotoxins, and some studies suggest that these elements might also be teratogens. Using a case-control study design, we investigated the relation between exposure to these heavy metals and neural tube defects (NTDs) in offspring of Mexican-American women living in 1 of the 14 Texas counties bordering Mexico. A total of 184 case-women with NTD-affected pregnancies and 225 control-women with normal live births were interviewed about their environmental and occupational exposures during the periconceptional period. Biologic samples for blood lead and urinary arsenic, cadmium, and mercury were also obtained for a subset of these women. Overall, the median levels of these biomarkers for heavy metal exposure did not differ significantly (P>0.05) between case- and control-women. However, among women in the highest income group, case-women were nine times more likely (95% confidence interval (CI) 1.4-57) than control-women to have a urinary mercury >=5.62{mu}g/L. Case-women were 4.2 times more likely (95% CI 1.1-16) to report burning treated wood during the periconceptional period than control-women. Elevated odds ratios (ORs) were observed for maternal and paternal occupational exposures to arsenic and mercury, but the 95% CIs were consistent with unity. The 95% CIs of the ORs were also consistent with unity for higher levels of arsenic, cadmium, lead, and mercury in drinking water and among women who lived within 2 miles at the time of conception to industrial facilities with reported emissions of any of these heavy metals. Our findings suggest that maternal exposures to arsenic, cadmium, or lead are probably not significant risk factors for NTDs in offspring. However, the elevated urinary mercury levels found in this population and exposures to the combustion of treated wood may warrant further investigation.

  14. Effects of maternal lead exposure on central nervous system maturation in postnatal rats

    SciTech Connect

    Coleman, J.C.

    1984-01-01

    Pups from female rats exposed to 40-to-80 mg of lead per liter in their drinking water (low-lead group) and 160-to-320 mg of lead per liter water (high-lead group) were examined at 1 to 18 days of age. Maximal electroshock seizure (MES) patterns were determined and, upon recovery, whole blood, plasma, cerebrospinal fluid (CSF) and cerebral cortex samples were collected. Approximately one-half of the pups was used to determine the cerebral cortical extracellular water space (ECS). The other half was used to determine whole blood lead concentrations, plasma electrolytes (Na/sup +/, K/sup +/ and Cl/sup -/), CSF electrolytes, and cerebral cortical lead content, electrolytes, total water spaces, protein content, DNA content, carbonic anhydrase (CA) activity, and sodium- potassium-activated adenosinetriphosphatase (Na/sup +//K/sup +/-ATPase) activity. Neither the low- nor the high-lead groups had significant changes in body weight, body length, hematocrit or cerebral wet weight at any age studied. Whole blood and cerebral cortical lead contents were increased, dose-dependently, at each day of age. Hyperexcitability as measured by MES was observed in lead-exposed pups at 6, 9 and 12 days of age. These observations demonstrate that prenatal and postnatal exposure to lead causes increased susceptibility to MES and alterations in normal developmental patterns of the cerebral cortex. Such alterations appear to result from the greater vulnerability of the glial population to the adverse effects of lead than are neutrons. Thus, effects on the glia can account for the electrolyte imbalances, cellular edema and hyperexcitability resulting from exposure to lead.

  15. Lead exposure and intelligence in 7-year-old children: the Yugoslavia Prospective Study.

    PubMed Central

    Wasserman, G A; Liu, X; Lolacono, N J; Factor-Litvak, P; Kline, J K; Popovac, D; Morina, N; Musabegovic, A; Vrenezi, N; Capuni-Paracka, S; Lekic, V; Preteni-Redjepi, E; Hadzialjevic, S; Slavkovich, V; Graziano, J H

    1997-01-01

    For a prospective study of lead exposure and early development, we recruited pregnant women from a lead smelter town and from an unexposed town in Yugoslavia and followed their children through 7 years of age. In this paper we consider associations between lifetime lead exposure, estimated by the area under the blood lead (BPb) versus time curve (AUC7), and intelligence, with particular concern for identifying lead's behavioral signature. The Wechsler Intelligence Scales for Children-Version III (WISC-III) was administered to 309 7-year-old children, 261 of whom had complete data on intelligence, blood lead, and relevant sociodemographic covariates (i.e., Home Observation for the Measurement of the Environment (HOME), birth weight, gender, sibship size, and maternal age, ethnicity, intelligence, and education). These showed anticipated associations with 7-year intelligence, explaining 41-4% of the variance in Full Scale, Performance, and Verbal IQ. Before covariate adjustment, AUC7 was unrelated to intelligence; after adjustment, AUC7 explained a significant 2.8%-4.2% of the variance in IQ. After adjustment, a change in lifetime BPb from 10 to 30 micro/dl related to an estimated decrease of 4.3 Full Scale IQ points; estimated decreases for Verbal and Performance IQ were 3.4 and 4.5 points, respectively. AUC7 was significantly and negatively related to three WISC-III factor scores: Freedom from Distractibility, Perceptual Organization, and Verbal Comprehension; the association with Perceptual Organization was the strongest. Consistent with previous studies, the IQ/lead association is small relative to more powerful social factors. Findings offer support for lead's behavioral signature; perceptual-motor skills are significantly more sensitive to lead exposure than are the language-related aspects of intelligence. Images Figure 1. A Figure 1. B Figure 1. C Figure 1. D Figure 2. PMID:9410739

  16. Maternal Blood, Plasma, and Breast Milk Lead: Lactational Transfer and Contribution to Infant Exposure

    PubMed Central

    Roy, Ananya; Amarasiriwardena, Chitra J.; Smith, Donald; Lupoli, Nicola; Mercado-García, Adriana; Lamadrid-Figueroa, Hector; Tellez-Rojo, Martha Maria; Hu, Howard; Hernández-Avila, Mauricio

    2013-01-01

    Background: Human milk is a potential source of lead exposure. Yet lactational transfer of lead from maternal blood into breast milk and its contribution to infant lead burden remains poorly understood. Objectives: We explored the dose–response relationships between maternal blood, plasma, and breast milk to better understand lactational transfer of lead from blood and plasma into milk and, ultimately, to the breastfeeding infant. Methods: We measured lead in 81 maternal blood, plasma, and breast milk samples at 1 month postpartum and in 60 infant blood samples at 3 months of age. Milk-to-plasma (M/P) lead ratios were calculated. Multivariate linear, piecewise, and generalized additive models were used to examine dose–response relationships between blood, plasma, and milk lead levels. Results: Maternal lead levels (mean ± SD) were as follows: blood: 7.7 ± 4.0 μg/dL; plasma: 0.1 ± 0.1 μg/L; milk: 0.8 ± 0.7 μg/L. The average M/P lead ratio was 7.7 (range, 0.6–39.8) with 97% of the ratios being > 1. The dose–response relationship between plasma lead and M/P ratio was nonlinear (empirical distribution function = 6.5, p = 0.0006) with the M/P ratio decreasing by 16.6 and 0.6 per 0.1 μg/L of plasma lead, respectively, below and above 0.1 μg/L plasma lead. Infant blood lead level (3.4 ± 2.2 μg/dL) increased by 1.8 μg/dL per 1 μg/L milk lead (p < 0.0001, R2 = 0.3). Conclusions: The M/P ratio for lead in humans is substantially higher than previously reported, and transfer of lead from plasma to milk may be higher at lower levels of plasma lead. Breast milk is an important determinant of lead burden among breastfeeding infants. Citation: Ettinger AS, Roy A, Amarasiriwardena CJ, Smith DR, Lupoli N, Mercado-García A, Lamadrid-Figueroa H, Tellez-Rojo MM, Hu H, Hernández-Avila M. 2014. Maternal blood, plasma, and breast milk lead: lactational transfer and contribution to infant exposure. Environ Health Perspect 122:87–92; http://dx.doi.org/10.1289/ehp

  17. The Developmental Competence of Oocytes Retrieved from The Leading Follicle in Controlled Ovarian Stimulated Cycles

    PubMed Central

    Braga, Daniela Paes de Almeida Ferreira; Bonetti, Tatiana Carvalho de Souza; da Silva, Ismael Dale Cotrim Guerreiro; Setti, Amanda Souza; Iaconelli, Assumpto Jr; Borges, Edson Jr

    2013-01-01

    Background: This study compares the developmental capacity of gametes retrieved from the largest follicle with small follicles of a cohort in controlled ovarian stimulated cycles. Materials and Methods: This prospective study performed in a private assisted fertilization center included 1016 follicles collected from 96 patients who underwent intra cytoplasmic sperm injection (ICSI). After follicular aspiration, oocytes were assigned to two groups according to the diameter of the derived follicle. The large follicle group (n=96) comprised oocytes derived from the leading follicle of the cohort and the small follicle group (n=920) consisted oocytes derived from the smaller follicles of the cohort. The fertilization and percentage of topquality embryos were compared between groups by Chi-square or Fisher’s exact test, where appropriate. The effect of the follicular diameter on oocyte dimorphism was assessed by binary logistic regression. Results: A significantly higher percentage of oocytes derived from the leading follicle were in the metaphase II (MII) stage (100 vs. 70.0%, p<0.001). However we observed no significant differences regarding the percentage of degenerated oocytes between the large (6.25%) and small follicle (5.0%) groups (p=0.550). Regression analysis demonstrated a nearly two-fold increase in the incidence of vacuoles in oocytes derived from the largest follicle of the cohort (OR: 1.81, p=0.046). The fertilization rate (50.0 vs. 38.8%, p=0.038) and the percentage of top quality embryos (84.7 vs. 76.4%, p=0.040) were significantly higher for oocytes derived from the largest follicle. However, the percentage of abnormal fertilized oocytes was equally distributed between the large follicle (15.0%) and small follicle (12. 8%) groups (p=0.550). Conclusion: Our data suggest that intrafollicular mechanisms within the larger follicle of the cohort may allow for these follicles to amplify the responsiveness to exogenous gonadotropin, which leads to the

  18. Lead Exposure and Tremor among Older Men: The VA Normative Aging Study

    PubMed Central

    Power, Melinda C.; Sparrow, David; Spiro, Avron; Hu, Howard; Louis, Elan D.; Weisskopf, Marc G.

    2015-01-01

    Background: Tremor is one of the most common neurological signs, yet its etiology is poorly understood. Case–control studies suggest an association between blood lead and essential tremor, and that this association is modified by polymorphisms in the δ-aminolevulinic acid dehydrogenase (ALAD) gene. Objective: We aimed to examine the relationship between lead and tremor, including modification by ALAD, in a prospective cohort study, using both blood lead and bone lead—a biomarker of cumulative lead exposure. Methods: We measured tibia (n = 670) and patella (n = 672) bone lead and blood lead (n = 807) among older men (age range, 50–98 years) in the VA Normative Aging Study cohort. A tremor score was created based on an approach using hand-drawing samples. ALAD genotype was dichotomized as ALAD-2 carriers or not. We used linear regression adjusted for age, education, smoking, and alcohol intake to estimate the associations between lead biomarkers and tremor score. Results: In unadjusted analyses, there was a marginal association between quintiles of all lead biomarkers and tremor scores (p-values < 0.13), which did not persist in adjusted models. Age was the strongest predictor of tremor. Among those younger than the median age (68.9 years), tremor increased significantly with blood lead (p = 0.03), but this pattern was not apparent for bone lead. We did not see modification by ALAD or an association between bone lead and change in tremor score over time. Conclusion: Our results do not strongly support an association between lead exposure and tremor, and suggest no association with cumulative lead biomarkers, although there is some suggestion that blood lead may be associated with tremor among the younger men in our cohort. Citation: Ji JS, Power MC, Sparrow D, Spiro A III, Hu H, Louis ED, Weisskopf MG. 2015. Lead exposure and tremor among older men: the VA Normative Aging Study. Environ Health Perspect 123:445–450; http://dx.doi.org/10.1289/ehp.1408535

  19. Exposure to lead induces hypoxia-like responses in bullfrog larvae (Rana catesbeiana)

    SciTech Connect

    Rice, T.M.; Blackstone, B.J.; Nixdorf, W.L.; Taylor, D.H.

    1999-10-01

    Amphibians collected around mining sites, areas with extensive automobile traffic, and shooting ranges have been documented to contain high levels of lead. Lead-exposed amphibians might respond as if in hypoxic conditions because exposure is known to decrease hemoglobin levels, damage erythrocytes, and alter respiratory surfaces. Therefore, the authors exposed bullfrog larvae to either 0 or 780 {micro}g/L Pb and either 3.50 or 7.85 mg/L oxygen for 7 d and monitored activity, trips to the surface, and buccal ventilation rates. Activity was significantly decreased in larvae exposed to low oxygen, Pb, or both compared to activity of larvae in high oxygen with no Pb. Larvae exposed to both Pb and low oxygen displayed higher buccal ventilation rates than larvae exposed to either treatment separately. Lead-exposed larvae surfaced significantly more often than unexposed larvae even under high-oxygen conditions. Lead-exposed larvae decreased in mass during the exposure period, whereas unexposed larvae increased in mass. Lead exposure could decrease survival of larvae in the field not only because of physiological problems due to decreased oxygen uptake but also because of greater predation pressure due to increased presence at the surface and reduced growth rates.

  20. Evaluation of four sampling methods for determining exposure of children to lead-contaminated household dust

    SciTech Connect

    Sterling, D.A.; Roegner, K.C.; Lewis, R.D.; Luke, D.A. . Div. of Environmental and Occupational Health); Wilder, L.C. . Div. of Health Assessment and Consultation); Burchette, S.M. )

    1999-08-01

    Childhood exposure to lead has been demonstrated to result in health effects and lead-contaminated household dust is a primary exposure source. There is a need to establish reliable methods for sampling surfaces to determine levels of lead contamination. Three vacuums (HVS3, GS80, and MVM) and one wipe method were evaluated for the collection of household floor dust under field sampling conditions within a Superfund site and demographically similar control area. Side-by-side floor samples were taken from three locations within 41 randomly selected households between August and September 1995: a child's bedroom, primary play area, and primary entrance. Analysis was performed to assess the relative collection performance of each sampler, spatial distribution of lead within a household, and correlation of lead loading with observed blood lead level, and to determine if discrete or composites samples were more predictive of blood lead levels. Approximately 90% of the floor surfaces were carpeted. The rank order of sampling methods from greatest to lowest collection efficiency was HVS3 > G80 > wipe > MVM. The HVS3 had the highest level of precision (CV = 0.05), with the GS80 and wipe precisions 0.48 and 0.053, respectively.

  1. Long-Term Exposure of Lead Acetate on Rabbit Renal Tissue

    PubMed Central

    Karimfar, Mohammad Hassan; Bargahi, Afshar; Moshtaghi, Darab; Farzadinia, Parviz

    2016-01-01

    Background: Lead has been widely used in different industries for ages. It is one of the heavy metals, highly poisonous even at low doses, and has biochemical, physiological and behavioral side effects on human and animals. It has been shown that lead has toxic effects on different tissues such as neural and genitourinary tissues, cardiovascular systems and blood. Therefore, high attention has been paid to its environmental pollutions. Objectives: Although many histological and biochemical studies have reported about the effects of lead on the renal tissue, there are a few studies about the ultrastructure and morphometric effects of lead on the kidney. Hence, the aim of this study was the evaluation of morphology and morphometrics of rabbit renal urinary barrier ultrastructure following long-term exposure to lead acetate. Materials and Methods: In this experimental study, 20 male New Zealand rabbits were divided into control and test groups (10 in each). The test group was injected intraperitoneally with chronic dose (8.5 mg/kg of body weight) of lead acetate and for the control group the same volume of normal saline was used, every other day for 10 weeks. After anesthetizing, the biopsies of renal tissues were taken for light and electron microscopic morphometric and morphologic analyses. Results: Long-term exposure to lead acetate caused histopathology effects including dilatation, congestion, nuclei heterochromatic effects, increase in diameter of renal tubules and urinary barrier thickness in rabbit renal tissue. Conclusions: Quantitative and qualitative results of long-term lead acetate exposure showed many histopathology side-effects, especially in the urinary barrier. PMID:27195142

  2. Lead concentration in the blood of the general population living near a lead-zinc mine site, Nigeria: Exposure pathways.

    PubMed

    Bello, Olanrewaju; Naidu, Ravi; Rahman, Mohammad Mahmudur; Liu, Yanju; Dong, Zhaomin

    2016-01-15

    Lead (Pb) poisoning in children is a major public health catastrophe worldwide. This report summarises both exposure pathways and blood Pb levels in children below 7 years of age and adults (above 18 years) from the Adudu community living near a lead-zinc mine in Nasawara, Nigeria. The average and median blood Pb levels in children and adults were 2.1 and 1.3 μg/dL, 3.1 and 1.8 μg/dL, respectively. However, Pb in 14% of adults' blood exceeded 5 μg/dL, which is the recommended threshold blood Pb concentration in adults as established by the Centers for Disease Control and Prevention (CDC). Furthermore 68% of adults' blood exceeded blood Pb action level of 2 μg/dL. For children, 11.4% and 31% of the blood samples exceeded 5 μg/dL and 2 μg/dL, respectively, while no safe blood Pb level in children has been recommended. In Nasawara, a significant difference (p<0.05) was observed between the various age groups in children with 2-4 years old having the highest levels and 6 year old children having the lowest Pb levels. Although this study did not detect elevated levels of Pb in children's blood in regions such as Zamfara, Nigeria and Kabwe, Zambia, a high percentage of samples exceeded 2 μg/dL. Soils, floor dusts, water and crops also reveal that Pb contamination in the study area could potentially be the major cause of blood Pb in the community exposed to mining. This study also observed a significant correlation between water Pb levels of adults and blood Pb levels, suggesting that water is the major exposure pathway. This analysis highlights the need to properly manage mining activities so that the health of communities living in the vicinity of a Pb-Zn mine is not compromised. PMID:26556755

  3. Methods for reducing lead exposure in young children and other risk groups: an integrated summary of a report to the U.S. Congress on childhood lead poisoning.

    PubMed Central

    Mushak, P; Crocetti, A F

    1990-01-01

    As part of a Congressionally mandated report on U.S. childhood lead poisoning prepared by the Federal government (U.S. Agency for Toxic Substances and Disease Registry [ATSDR]), the authors have analyzed the relative effectiveness of measures to reduce source-specific lead exposure of U.S. children. An integrated overview of this analysis is presented in this article. Two national actions, the Federally mandated phasedown of lead in gasoline by the U.S. Environmental Protection Agency and the voluntary phasedown of lead use in domestic food can production, are examples of centrally directed initiatives that have been relatively successful in limiting childhood lead exposure in the U.S. Efforts to abate lead-based paint exposure of children have largely failed. This is especially true for the nation's 21 million residential units with the highest lead content paint. Similarly, abatement of lead exposure from contaminated dusts and soils has generally been unsuccessful. Comprehensive measures to reduce lead exposure from drinking water in residences and public facilities, e.g., elementary schools, are only now being promulgated or implemented. The full extent of their effectiveness remains to be demonstrated. There are many miscellaneous but potentially severe exposure sources that are difficult to control but require attention, such as poorly glazed foodware and ethno-specific preparations. PMID:2088738

  4. An exposure and health risk assessment of lead (Pb) in lipstick.

    PubMed

    Monnot, Andrew D; Christian, Whitney V; Abramson, Matthew M; Follansbee, Mark H

    2015-06-01

    Lead (Pb) content in lipstick and other consumer products has become an increasing concern. In 2010, the United States Food and Drug Administration tested 400 lipstick samples and found a maximum Pb concentration of 7.19 ppm. To assess the safety of lipstick in adults that chronically apply lipstick as well as instances where children might incidentally ingest lipstick products, the United States Environmental Protection Agency's (US EPA) Adult Lead Model and Integrated Exposure Uptake Biokinetic Model for Lead in Children were used to determine the blood Pb concentrations of adults and children ingesting varying amounts of lipstick of different Pb concentrations. Modeled blood Pb concentrations were compared with oral ingestion guidelines and to the Centers for Disease Control and the US EPA's actionable blood Pb levels of 5 and 10 µg/dL. Background Pb exposure was the primary contributor to estimated blood Pb levels (BLLs) in children and adults, and Pb exposure from lipstick did not significantly increase estimated BLLs. These results suggest that the safety of consumer products and cosmetics should be assessed not only by the presence and amounts of hazardous contents, but also in conjunction with an assessment of estimated background exposures and comparison to health-based standards. PMID:25839902

  5. Indicators of lead, zinc and cadmium exposure in cattle. I. Results in a polluted area

    SciTech Connect

    Milhaud, G.E.; Mehennaoui, S.

    1988-12-01

    Dairy cattle on a farm located in the vicinity of a lead and zinc-ore processing factory were studied over 21 mo and compared with cattle on a control farm. Mean daily intakes of lead from the diet were 4.3 mg/kg body weight, with great variations; mean daily zinc intakes were 5.6 mg/kg body weight; and mean daily cadmium intakes were 0.064 mg/kg body weight. The 3 major indicators of contamination were blood lead concentrations, with mean values of 50 micrograms/100 ml of blood, zinc protoporphyrin with mean values of 165 micrograms/100 ml blood, and lead concentrations in hair which averaged 10 micrograms/g. Blood zinc concentrations and zinc concentrations were not significantly increased. One cow developed fatal post-partum paralysis. Liver, kidney and bone lead concentrations and kidney cadmium concentrations were good ''post-mortem'' indicators of exposure.

  6. [Influence of chronic lead exposure on resistence to bacterial infection (author's transl)].

    PubMed

    Ewers, U; Weisser, L; Wegner, A

    1980-01-01

    Suppression by lead of resistance to bacterial or viral infections has been reported by several authors. We have studied, if a decrease of resistance to bacterial infection could be evaluated at blood lead concentrations (PbB), which correspond to the upper levels of environmental or occupational lead exposure regarded as tolerable (PbB = 35 resp. 60 microgram/100 ml). NMRI mice were chronically exposed to lead by feeding with lead acetate containing diets and given a challenge with Salmonella typhimurium. No increase of susceptibility to bacterial infection could be demonstrated at PbB < 90 microgram/100 g. At PbB > 100 microgram/100 g, however, an increase of lethality and a decrease of 50% survival times could be observed after bacterial infection. PMID:6999813

  7. Boys, not girls, are negatively affected on cognitive tasks by lead exposure: a pilot study.

    PubMed

    Khanna, Maya M

    2015-01-01

    The study described in this article provides behavioral evidence that boys experience the deleterious cognitive effects of lead more than girls do. In fact, girls with elevated blood lead levels (BLLs - 10 μg/dL) performed as well as girls without elevated BLLs on behavioral measures of cognition. This was shown by testing executive function and reading readiness skills of 40 young children (aged three to six years; 23 with elevated blood lead levels, 17 without) residing within a U.S. Environmental Protection Agency-designated lead Superfund site. The results also indicate that elevated BLLs are related to a more pronounced negative impact on executive function than on reading readiness. These findings support recent research on adults indicating that lead exposure is related to atrophy within the prefrontal cortex and other work suggesting that estrogen and estradiol may act as neuroprotectants against the negative impact of neurotoxins. PMID:25619039

  8. Lead, mercury, and cadmium exposure and attention deficit hyperactivity disorder in children

    SciTech Connect

    Kim, Stephani; Arora, Monica; Fernandez, Cristina; Landero, Julio; Caruso, Joseph; Chen, Aimin

    2013-10-15

    Background: There is limited research examining the relationship between lead (Pb) exposure and medically diagnosed attention deficit hyperactivity disorder (ADHD) in children. The role of mercury (Hg) and cadmium (Cd) exposures in ADHD development is even less clear. Objectives: To examine the relationship between Pb, Hg, and Cd and ADHD in children living inside and outside a Lead Investigation Area (LIA) of a former lead refinery in Omaha, NE. Methods: We carried out a case-control study with 71 currently medically diagnosed ADHD cases and 58 controls from a psychiatric clinic and a pediatric clinic inside and outside of the LIA. The participants were matched on age group (5–8, 9–12 years), sex, race (African American or Caucasians and others), and location (inside or outside LIA). We measured whole blood Pb, total Hg, and Cd using inductively coupled plasma mass spectrometry. Results: Inside the LIA, the 27 cases had blood Pb geometric mean (GM) 1.89 µg/dL and the 41 controls had 1.51 µg/dL. Outside the LIA, the 44 cases had blood Pb GM 1.02 µg/dL while the 17 controls had 0.97 µg/dL. After adjustment for matching variables and maternal smoking, socioeconomic status, and environmental tobacco exposure, each natural log unit blood Pb had an odds ratio of 2.52 with 95% confidence interval of 1.07–5.92. Stratification by the LIA indicated similar point estimate but wider CIs. No associations were observed for Hg or Cd. Conclusions: Postnatal Pb exposure may be associated with higher risk of clinical ADHD, but not the postnatal exposure to Hg or Cd. -- Highlights: • Blood Pb levels are associated with ADHD diagnosis in children. • No association was found between blood Cd or Hg levels and ADHD. • Children living close to hazardous waste site need to reduce metal exposure.

  9. Association of lead and cadmium exposure with frailty in US older adults

    SciTech Connect

    García-Esquinas, Esther; Navas-Acien, Ana; Pérez-Gómez, Beatriz; Artalejo, Fernando Rodríguez

    2015-02-15

    Background: Environmental lead and cadmium exposure is associated with higher risk of several age-related chronic diseases, including cardiovascular disease, chronic kidney disease and osteoporosis. These diseases may lead to frailty, a geriatric syndrome characterized by diminished physiologic reserve in multiple systems with decreased ability to cope with acute stressors. However, no previous study has evaluated the association between lead or cadmium exposure and frailty. Methods: Cross-sectional study among individuals aged ≥60 years who participated in the third U.S. National Health and Nutrition Examination Survey and had either blood lead (N=5272) or urine cadmium (N=4887) determinations. Frailty was ascertained with a slight modification of the Fried criteria, so that individuals meeting ≥3 of 5 pre-defined criteria (exhaustion, low body weight, low physical activity, weakness and slow walking speed), were considered as frail. The association between lead and cadmium with frailty was evaluated using logistic regression with adjustment for relevant confounders. Results: Median (intertertile range) concentrations of blood lead and urine cadmium were 3.9 µg/dl (2.9–4.9) and 0.62 µg/l (0.41–0.91), respectively. The prevalence of frailty was 7.1%. The adjusted odds ratios (95% confidence interval) of frailty comparing the second and third to the lowest tertile of blood lead were, respectively, 1.40 (0.96–2.04) and 1.75 (1.33–2.31). Lead concentrations were also associated with the frequency of exhaustion, weakness and slowness. The corresponding odds ratios (95% confidence interval) for cadmium were, respectively, 0.97 (0.68–1.39) and 1.55 (1.03–2.32), but this association did not hold after excluding participants with reduced glomerular filtration rate: 0.70 (0.43–1.14) and 1.09 (0.56–2.11), respectively. Conclusions: In the US older adult population, blood lead but not urine cadmium concentrations showed a direct dose

  10. Endocrine mechanisms underlying the growth effects of developmental lead exposure in the rat.

    PubMed

    Ronis, M J; Badger, T M; Shema, S J; Roberson, P K; Templer, L; Ringer, D; Thomas, P E

    1998-05-22

    A dose-response study was conducted to examine the growth suppression associated with developmental lead exposure in a rat model and to determine the endocrine mechanisms underlying these effects. Ad libitum intake of lead acetate (0.05% to 0.45% w/v) was initiated in time-impregnated female Sprague-Dawley rats (n = 10-15/group) at gestational day 5. At birth, pups were culled to four male and four females per litter. Lead exposure of dams continued until weaning, following which lead exposure of pups was continued until sacrifice at age 2 , 35, 55, and 85 days. Birth weight and prepubertal and pubertal growth rates were significantly suppressed. Growth rates were suppressed to a much greater degree in male as compared to female pups. Decreased growth rates were accompanied by a significant decrease in plasma insulin-like growth factor 1 (IGF1) concentrations and (1) a significant increase in pituitary growth hormone (GH) content during puberty in pups of both sexes, (2) a delay in the developmental profiles of the GH-dependent male-specific liver enzymes cytochrome P-450 CYP2C11 and N-hydroxy-2-acetylaminofluorene sulfotransferase, and (3) continued suppression of these enzymes in lead-exposed adult male pups. In addition, significant decreases in plasma sex steroids, testosterone (male) and 17beta-estradiol (female), were observed during puberty. Postpuberty, at age 85 d, both IGF1 and sex steroid levels were indistinguishable from control pups despite continued lead exposure. Growth rates were also similar in control and lead-exposed pups between age 57 and 85 d. Data suggest that the mechanism underlying lead-induced sex-independent suppression of growth observed in these studies involves disruption of GH secretion during puberty. It is possible that the mechanisms underlying the greater suppression of somatic growth observed at puberty in lead-exposed male offspring may be due to the additional hypoandrogenization produced by the action of lead on the

  11. Constraining Paleo-Glacier Dynamics Using Optically Stimulated Luminescence (OSL) Bedrock Exposure Dating

    NASA Astrophysics Data System (ADS)

    Brun, F.; Valla, P.; King, G. E.; Herman, F.

    2014-12-01

    Quantifying glacier dynamics over the late-Pleistocene remains an important challenge for understanding glacial response to climate change. Historical glacier reconstructions are spatially limited (e.g. the European Alps) and cover only the last ~100 yrs, restricting their use as paleoclimatic proxies. Bedrock dating methods such as Terrestrial Cosmogenic Nuclides (TCN) dating or lichenometry allows glacier fluctuations to be reconstructed over longer timescales. However, these methods have limited temporal resolution, and therefore do not enable accurate dating of recent glacier fluctuations (e.g. short glacier re-advances). Here, we use a novel in situ dating method based on Optically Stimulated Luminescence (OSL) to fill this temporal/spatial gap. OSL dating is based on the time-accumulation of trapped electrons in the lattice defects of minerals. OSL-exposure dating is based on the bleaching (i.e. resetting) of the minerals' luminescence signal when they are exposed to light (Sohbati et al., 2012 JGR-Solid Earth), which depends on exposure time, effective photon flux and light attenuation by minerals. We analyzed 10 samples in the Val d'Hérens (Swiss Alps) where post-LGM glacier dynamics remain poorly constrained and short glacier re-advances are thought to occur during the Holocene. Bedrock samples were drilled and small cores were sliced into 1-mm thick discs from which natural luminescence profiles were measured. We calibrated the luminescence model parameters using historically-exposed bedrock samples (~100 yr) near the Mont-Miné glacier, and used this on-site calibration to date surface exposure of glacial bedrock at various elevations along the valley; initial relative dating results are promising. Although OSL-exposure dating appears an efficient tool for historical glacier reconstructions, OSL bleaching over longer timescales (i.e. late-Pleistocene to Holocene) requires more investigation before use as a chronometer.

  12. Elevated Blood Lead Levels in Infants and Mothers in Benin and Potential Sources of Exposure

    PubMed Central

    Bodeau-Livinec, Florence; Glorennec, Philippe; Cot, Michel; Dumas, Pierre; Durand, Séverine; Massougbodji, Achille; Ayotte, Pierre; Le Bot, Barbara

    2016-01-01

    Lead in childhood is well known to be associated with poor neurodevelopment. As part of a study on maternal anemia and offspring neurodevelopment, we analyzed blood lead level (BLL) with no prior knowledge of lead exposure in 225 mothers and 685 offspring 1 to 2 years old from Allada, a semi-rural area in Benin, sub-Saharan Africa, between May 2011 and May 2013. Blood samples were analyzed by inductively coupled plasma mass spectrometry. Environmental assessments in households and isotopic ratio measurements were performed for eight children with BLL > 100 µg/L. High lead levels (BLL > 50 µg/L) were found in 44% of mothers and 58% of children. The median BLL was 55.1 (interquartile range 39.2–85.0) and 46.6 (36.5–60.1) µg/L, respectively. Maternal BLL was associated with offspring’s consumption of piped water and animals killed by ammunition. Children’s BLL was associated with presence of paint chips in the house and consumption of animals killed by ammunition. In this population, with 98% of children still breastfed, children’s BLL was highly associated with maternal BLL on multivariate analyses. Environmental measures and isotopic ratios supported these findings. Offspring may be highly exposed to lead in utero and probably via breastfeeding in addition to lead paint exposure. PMID:26978384

  13. Elevated Blood Lead Levels in Infants and Mothers in Benin and Potential Sources of Exposure.

    PubMed

    Bodeau-Livinec, Florence; Glorennec, Philippe; Cot, Michel; Dumas, Pierre; Durand, Séverine; Massougbodji, Achille; Ayotte, Pierre; Le Bot, Barbara

    2016-03-01

    Lead in childhood is well known to be associated with poor neurodevelopment. As part of a study on maternal anemia and offspring neurodevelopment, we analyzed blood lead level (BLL) with no prior knowledge of lead exposure in 225 mothers and 685 offspring 1 to 2 years old from Allada, a semi-rural area in Benin, sub-Saharan Africa, between May 2011 and May 2013. Blood samples were analyzed by inductively coupled plasma mass spectrometry. Environmental assessments in households and isotopic ratio measurements were performed for eight children with BLL > 100 µg/L. High lead levels (BLL > 50 µg/L) were found in 44% of mothers and 58% of children. The median BLL was 55.1 (interquartile range 39.2-85.0) and 46.6 (36.5-60.1) µg/L, respectively. Maternal BLL was associated with offspring's consumption of piped water and animals killed by ammunition. Children's BLL was associated with presence of paint chips in the house and consumption of animals killed by ammunition. In this population, with 98% of children still breastfed, children's BLL was highly associated with maternal BLL on multivariate analyses. Environmental measures and isotopic ratios supported these findings. Offspring may be highly exposed to lead in utero and probably via breastfeeding in addition to lead paint exposure. PMID:26978384

  14. Cognitive disparities, lead plumbing, and water chemistry: prior exposure to water-borne lead and intelligence test scores among World War Two U.S. Army enlistees.

    PubMed

    Ferrie, Joseph P; Rolf, Karen; Troesken, Werner

    2012-01-01

    Higher prior exposure to water-borne lead among male World War Two U.S. Army enlistees was associated with lower intelligence test scores. Exposure was proxied by urban residence and the water pH levels of the cities where enlistees lived in 1930. Army General Classification Test scores were six points lower (nearly 1/3 standard deviation) where pH was 6 (so the water lead concentration for a given amount of lead piping was higher) than where pH was 7 (so the concentration was lower). This difference rose with time exposed. At this time, the dangers of exposure to lead in water were not widely known and lead was ubiquitous in water systems, so these results are not likely the effect of individuals selecting into locations with different levels of exposure. PMID:22014834

  15. Human health risk assessment of lead from mining activities at semi-arid locations in the context of total lead exposure.

    PubMed

    Zheng, Jiajia; Huynh, Trang; Gasparon, Massimo; Ng, Jack; Noller, Barry

    2013-12-01

    Lead from historical mining and mineral processing activities may pose potential human health risks if materials with high concentrations of bioavailable lead minerals are released to the environment. Since the Joint Expert Committee on Food Additives of Food and Agriculture Organization/World Health Organization withdrew the Provisional Tolerable Weekly Intake of lead in 2011, an alternative method was required for lead exposure assessment. This study evaluated the potential lead hazard to young children (0-7 years) from a historical mining location at a semi-arid area using the U.S. EPA Integrated Exposure Uptake Biokinetic (IEUBK) Model, with selected site-specific input data. This study assessed lead exposure via the inhalation pathway for children living in a location affected by lead mining activities and with specific reference to semi-arid conditions and made comparison with the ingestion pathway by using the physiologically based extraction test for gastro-intestinal simulation. Sensitivity analysis for major IEUBK input parameters was conducted. Three groups of input parameters were classified according to the results of predicted blood concentrations. The modelled lead absorption attributed to the inhalation route was lower than 2 % (mean ± SE, 0.9 % ± 0.1 %) of all lead intake routes and was demonstrated as a less significant exposure pathway to children's blood, compared with ingestion. Whilst dermal exposure was negligible, diet and ingestion of soil and dust were the dominant parameters in terms of children's blood lead prediction. The exposure assessment identified the changing role of dietary intake when house lead loadings varied. Recommendations were also made to conduct comprehensive site-specific human health risk assessment in future studies of lead exposure under a semi-arid climate. PMID:24122159

  16. Poisoning of wild birds from exposure to anticholinesterase compounds and lead: diagnostic methods and selected cases

    USGS Publications Warehouse

    Franson, J.C.; Smith, M.R.

    1999-01-01

    Organophosphorus and carbamate compounds have largely replaced chlorinated hydrocarbons for pesticidal use in the United States, and many cases of poisoning resulting from exposure to these anticholinesterase agents have occurred in free-living birds. Although lead shot has been prohibited for waterfowl hunting throughout the United States since 1991, lead poisoning from the ingestion of spent lead shot is still occasionally seen in wild birds, and lead poisoning from the ingestion of fishing sinkers is an emerging issue of concern. A thorough history, a complete necropsy evaluation, and appropriate laboratory analysis of tissues are required to diagnose toxicoses in wild birds, including those caused by anticholinesterase compounds and lead. The interpretation of brain cholinesterase (ChE) activity results depends on the methods of analysis and comparison with expected normal enzyme activities in brain tissue from the same species. Although lead residues in tissues vary among species, many lead poisoned birds have tissue residues that are much higher than the lower threshold commonly accepted for a diagnosis of lead poisoning. We review histories, necropsy findings, and analytical methodologies and results for selected anticholinesterase and lead poisoning cases diagnosed in wild raptors, waterfowl, and loons.

  17. Assessment of lead exposure in Spanish imperial eagle (Aquila adalberti) from spent ammunition in central Spain

    USGS Publications Warehouse

    Fernandez, Julia Rodriguez-Ramos; Hofle, Ursula; Mateo, Rafael; de Francisco, Olga Nicolas; Abbott, Rachel; Acevedo, Pelayo; Blanco, Juan-Manuel

    2011-01-01

    The Spanish imperial eagle (Aquila adalberti) is found only in the Iberian Peninsula and is considered one of the most threatened birds of prey in Europe. Here we analyze lead concentrations in bones (n = 84), livers (n = 15), primary feathers (n = 69), secondary feathers (n = 71) and blood feathers (n = 14) of 85 individuals collected between 1997 and 2008 in central Spain. Three birds (3.6%) had bone lead concentration > 20 (mu or u)g/g and all livers were within background lead concentration. Bone lead concentrations increased with the age of the birds and were correlated with lead concentration in rachis of secondary feathers. Spatial aggregation of elevated bone lead concentration was found in some areas of Montes de Toledo. Lead concentrations in feathers were positively associated with the density of large game animals in the area where birds were found dead or injured. Discontinuous lead exposure in eagles was evidenced by differences in lead concentration in longitudinal portions of the rachis of feathers.

  18. Heat exposure and the toxicity of one number four lead shot in Mallards, Anas platyrhynchos

    SciTech Connect

    Srebocan, E.; Rattner, B.A.

    1988-02-01

    Lead poisoning from ingested shot is a major cause of mortality in waterfowl throughout the world. In North America, most waterfowl that die from lead poisoning succumb following the hunting season. Cold and harsh winter weather is generally thought to exacerbate lead toxicity in birds. Although largely undocumented, there is considerable opportunity for birds to ingest lead shot in the summer during periods of extreme heat. Substantial lead exposure in over 50% of the American black ducks (Anas rubripes) captured in late summer has been observed in areas of the Chesapeake Bay. Moreover, investigations with rodents, rabbits, and man have demonstrated that the toxicity of lead is increased by high environmental temperature, possibly caused by elevated metabolic rate, dehydration, and impaired lead excretion. A recent study in which black ducks were dosed with a single number 4 lead shot suggested that toxicity may be enhanced during periods of extreme hot weather. To further investigate this finding, the authors examined lead toxicity in mallards maintained at thermoneutral temperature (21/sup 0/C) and at an elevated temperature (35/sup 0/C) approaching the upper critical limit.

  19. BEAM EXPOSURE DEPENDENCE AND MECHANISMS OF PHOTON-STIMULATED DESORPTION FROM ALKALI FLUORIDES

    SciTech Connect

    Parks, C.C.; Shirley, D.A.; Loubriel, G.

    1983-11-01

    Photon-stimulated desorption experiments were performed on the (001) face of LiF for photon energies near the F(2s) and Li(ls) edges (from 37 to 72 eV). There are structures in the F{sup +} yield above the F(2s) edge which are absent in the Li{sup +} spectrum, differences in detail in the Li{sup +} and F{sup +} yields near the Li(1s) edge, and considerable broadening of the desorption yields as compared to the bulk photoabsorption spectrum. The first observation of a strong x-ray, and visible, beam exposure dependence of ion yields from LiF and NaF is also presented. These results are discussed in terms of electronic and defect properties of alkali halides.

  20. Exposure of Unwounded Plants to Chemical Cues Associated with Herbivores Leads to Exposure-Dependent Changes in Subsequent Herbivore Attack

    PubMed Central

    Orrock, John L.

    2013-01-01

    Although chemical predator cues often lead to changes in the anti-predator behavior of animal prey, it is not clear whether non-volatile herbivore kairomones (i.e. incidental chemical cues produced by herbivore movement or metabolism but not produced by an attack) trigger the induction of defense in plants prior to attack. I found that unwounded plants (Brassica nigra) that were regularly exposed to kairomones from snails (mucus and feces produced during movement of Helix aspersa) subsequently experienced reduced rates of attack by snails, unlike unwounded plants that received only one initial early exposure to snail kairomones. A follow-up experiment found that mucus alone did not affect snail feeding on previously harvested B. oleracea leaves, suggesting that changes in herbivory on B. nigra were due to changes in plant quality. The finding that chemicals associated with herbivores leads to changes in palatability of unwounded plants suggests that plants eavesdrop on components of non-volatile kairomones of their snail herbivores. Moreover, this work shows that the nature of plant exposure matters, supporting the conclusion that plants that have not been attacked or wounded nonetheless tailor their use of defenses based on incidental chemical information associated with herbivores and the timing with which cues of potential attack are encountered. PMID:24278210

  1. Exposure of unwounded plants to chemical cues associated with herbivores leads to exposure-dependent changes in subsequent herbivore attack.

    PubMed

    Orrock, John L

    2013-01-01

    Although chemical predator cues often lead to changes in the anti-predator behavior of animal prey, it is not clear whether non-volatile herbivore kairomones (i.e. incidental chemical cues produced by herbivore movement or metabolism but not produced by an attack) trigger the induction of defense in plants prior to attack. I found that unwounded plants (Brassica nigra) that were regularly exposed to kairomones from snails (mucus and feces produced during movement of Helix aspersa) subsequently experienced reduced rates of attack by snails, unlike unwounded plants that received only one initial early exposure to snail kairomones. A follow-up experiment found that mucus alone did not affect snail feeding on previously harvested B. oleracea leaves, suggesting that changes in herbivory on B. nigra were due to changes in plant quality. The finding that chemicals associated with herbivores leads to changes in palatability of unwounded plants suggests that plants eavesdrop on components of non-volatile kairomones of their snail herbivores. Moreover, this work shows that the nature of plant exposure matters, supporting the conclusion that plants that have not been attacked or wounded nonetheless tailor their use of defenses based on incidental chemical information associated with herbivores and the timing with which cues of potential attack are encountered. PMID:24278210

  2. Lead exposure and visual-motor abilities in children from Chennai, India.

    PubMed

    Palaniappan, Kavitha; Roy, Ananya; Balakrishnan, Kalpana; Gopalakrishnan, Lakshmi; Mukherjee, Bhramar; Hu, Howard; Bellinger, David C

    2011-08-01

    Lead exposure poses a major environmental hazard in India, but little information is available on the impact of lead exposure on visuo-motor development in Indian children. We hypothesize that higher blood lead levels are associated with poorer visual-motor, visual-spatial and fine motor functioning among children. We conducted a cross-sectional study of 814 school children, aged 3-7 years. Lead in whole blood was measured using the LeadCare Analyzer. The Wide Range of Visual Motor Abilities Test (WRAVMA) was administered to each child by trained examiners. The mean blood lead level was 11.4±5.3 μg/dL. In multivariate analyses adjusting for mother's education level, father's education level, average monthly income, hemoglobin and sex, WRAVMA scores were inversely related to blood lead level. An increase of 10 μg/dL was associated with a decrease of 2.6 points (95% CI: -4.5 to -0.7, P=0.006) in the Visual Motor Composite score and a decrease of 2.9 points (95% CI: -5.1 to -0.7, P=0.011) in the Drawing subtest. Exploration of the shape of the dose-effect relationships using spline functions indicated some non-linearities, with the steepest declines in visual-motor skills occurring at higher blood lead levels. Among urban Indian children, higher blood lead levels are associated with decreased visual-motor abilities, particularly visual-motor integration. PMID:21510976

  3. Chronic Nicotine Exposure Stimulates Biliary Growth and Fibrosis in Normal Rats

    PubMed Central

    Jensen, Kendal; Afroze, Syeda; Ueno, Yoshiyuki; Rahal, Kinan; Frenzel, Amber; Sterling, Melanie; Guerrier, Micheleine; Nizamutdinov, Damir; Dostal, David E.; Meng, Fanyin; Glaser, Shannon S.

    2013-01-01

    Background: Epidemiological studies have indicated smoking to be a risk factor for the progression of liver diseases. Nicotine is the chief addictive substance in cigarette smoke and has powerful biological properties throughout the body. Nicotine has been implicated in a number of disease processes, including increased cell proliferation and fibrosis in several organ systems. Aims: The aim of this study was to evaluate the effects of chronic administration of nicotine on biliary proliferation and fibrosis in normal rats. Methods: In vivo, rats were treated with nicotine by osmotic minipumps for two weeks. Proliferation, α7-nicotinic receptor (α7-nAChR) and profibrotic expression were evaluated in liver tissue, cholangiocytes and a polarized cholangiocyte cell line (NRIC). Nicotine-dependent activation of the Ca2+/IP3/ERK 1/2 intracellular signaling pathway was also evaluated in NRIC. Results: Cholangiocytes express α7-nAChR. Chronic administration of nicotine to normal rats stimulated biliary proliferation and profibrotic gene and protein expression such as alpha-smooth muscle actin (α-SMA) and fibronectin 1 (FN-1). Activation of α7-nAChR stimulated Ca2+/ERK1/2-dependent cholangiocyte proliferation. Conclusion: Chronic exposure to nicotine contributes to biliary fibrosis by activation of cholangiocyte proliferation and expression of profibrotic genes. Modulation of α7-nAChR signaling axis may be useful for the management of biliary proliferation and fibrosis during cholangiopathies. PMID:23587498

  4. Do electrically stimulated sensory inputs and movements lead to long-term plasticity and rehabilitation gains?

    PubMed

    Dobkin, Bruce H

    2003-12-01

    Peripheral and cortical magnetic and electrical stimulation may find a therapeutic niche as augmentative rehabilitation interventions for lessening impairments and disabilities after brain and spinal cord injury. The momentum for these approaches arose from recent physiological studies that examined the effects of paradigms of stimulation on synaptic and biological adaptations within the cortex and lumbar cord. A case report about improvements made by Christopher Reeve is driving requests by patients with profound spinal cord injury for interventions that include resistance pedaling facilitated by electrical neuromuscular stimulation. Although the evidence for this particular approach is less than convincing, reorganization-inducing cortical and peripheral afferent stimulation protocols offer insights into the steps needed for scientific designs of these potential rehabilitation interventions. PMID:14624077

  5. Cancer and occupational exposure to inorganic lead compounds: a meta-analysis of published data.

    PubMed Central

    Fu, H; Boffetta, P

    1995-01-01

    OBJECTIVES--To review and summarise the epidemiological evidence on the carcinogenicity of occupational exposure to inorganic lead. METHODS--Case-control and cohort studies were reviewed and combined for meta-analysis. Fixed and random effect methods were used to estimate the summary effects. RESULTS--The combined results show a significant excess risk of overall cancer, stomach cancer, lung cancer, and bladder cancer, with relative risk ratios (RRs) and 95% confidence intervals (95% CIs) in the meta-analysis of 1.11 (1.05-1.17), 1.33 (1.18-1.49), 1.29 (1.10-1.50), and 1.41 (1.16-1.71) respectively. The RR (95% CI) for kidney cancer was also high, but did not reach significance (1.19 (0.96-1.48)). A separate analysis of studies of heavily exposed workers provided slightly increased RRs for cancers of the stomach (1.50) and lung (1.42). CONCLUSIONS--The findings from the workers with heavy exposure to lead provided some evidence to support the hypothesis of an association between stomach and lung cancer and exposure to lead. The main limitation of the present analysis is that the excess risks do not take account of potential confounders, because little information was available for other occupational exposures, smoking, and dietary habits. To some extent, the risk of lung cancer might be explained by confounders such as tobacco smoking and exposure to other occupational carcinogens. The excess risk of stomach cancer may also be explained, at least in part, by non-occupational factors. For bladder and kidney cancers, the excess risks are only suggestive of a true effect because of possible publication bias. PMID:7757170

  6. Lead, Mercury, and Cadmium Exposure and Attention Deficit Hyperactivity Disorder in Children

    PubMed Central

    Kim, Stephani; Arora, Monica; Fernandez, Cristina; Caruso, Joseph; Landero, Julio; Chen, Aimin

    2013-01-01

    Background There is limited research examining the relationship between lead (Pb) exposure and medically diagnosed Attention Deficit Hyperactivity Disorder (ADHD) in children. The role of mercury (Hg) and cadmium (Cd) exposures in ADHD development is even less clear. Objectives To examine the relationship between Pb, Hg, and Cd and ADHD in children living inside and outside a Lead Investigation Area (LIA) of a former lead refinery in Omaha, NE. Methods We carried out a case-control study with 71 currently medically diagnosed ADHD cases and 58 controls from a psychiatric clinic and a pediatric clinic inside and outside of the LIA. The participants were matched on age group (5–8, 9–12 years), sex, race (African American or Caucasians and Others), and location (inside or outside LIA). We measured whole blood Pb, total Hg, and Cd using Inductively Coupled Plasma Mass Spectrometry. Results Inside the LIA, the 27 cases had blood Pb Geometric Mean (GM) 1.89 µg/dL and the 41 controls had 1.51 µg/dL. Outside the LIA, the 44 cases had blood Pb GM 1.02 µg/dL while the 17 controls had 0.97 µg/dL. After adjustment for matching variables and maternal smoking, socioeconomic status, and environmental tobacco exposure, each natural log unit blood Pb had an odds ratio of 2.52 with 95% confidence interval of 1.07–5.92. Stratification by the LIA indicated similar point estimate but wider CIs. No associations were observed for Hg or Cd. Conclusions Postnatal Pb exposure may be associated with higher risk of clinical ADHD, but not the postnatal exposure to Hg or Cd. PMID:24034783

  7. Chronic Lead Exposure Increases Blood Pressure and Myocardial Contractility in Rats

    PubMed Central

    Fioresi, Mirian; Simões, Maylla Ronacher; Furieri, Lorena Barros; Broseghini-Filho, Gilson Brás; Vescovi, Marcos Vinícius A.; Stefanon, Ivanita; Vassallo, Dalton Valentim

    2014-01-01

    We investigated the cardiovascular effects of lead exposure, emphasising its direct action on myocardial contractility. Male Wistar rats were sorted randomly into two groups: control (Ct) and treatment with 100 ppm of lead (Pb) in the drinking water. Blood pressure (BP) was measured weekly. At the end of the treatment period, the animals were anaesthetised and haemodynamic parameters and contractility of the left ventricular papillary muscles were recorded. Blood and tissue samples were properly stored for further biochemical investigations. Statistical analyses were considered to be significant at p<0.05. The lead concentrations in the blood reached approximately 13 µg/dL, while the bone was the site of the highest deposition of this metal. BP in the Pb-treated group was higher from the first week of lead exposure and remained at the same level over the next four weeks. Haemodynamic evaluations revealed increases in systolic (Ct: 96±3.79 vs. Pb: 116±1.37 mmHg) and diastolic blood pressure (Ct: 60±2.93 vs. Pb: 70±3.38 mmHg), left ventricular systolic pressure (Ct: 104±5.85 vs. Pb: 120±2.51 mmHg) and heart rate (Ct: 307±10 vs. Pb: 348±16 bpm). Lead treatment did not alter the force and time derivatives of the force of left ventricular papillary muscles that were contracting isometrically. However, our results are suggestive of changes in the kinetics of calcium (Ca++) in cardiomyocytes increased transarcolemmal Ca++ influx, low Ca++ uptake by the sarcoplasmic reticulum and high extrusion by the sarcolemma. Altogether, these results show that despite the increased Ca++ influx that was induced by lead exposure, the myocytes had regulatory mechanisms that prevented increases in force, as evidenced in vivo by the increased systolic ventricular pressure. PMID:24841481

  8. Lead Bullet Fragments in Venison from Rifle-Killed Deer: Potential for Human Dietary Exposure

    PubMed Central

    Hunt, W. Grainger; Watson, Richard T.; Oaks, J. Lindsay; Parish, Chris N.; Burnham, Kurt K.; Tucker, Russell L.; Belthoff, James R.; Hart, Garret

    2009-01-01

    Human consumers of wildlife killed with lead ammunition may be exposed to health risks associated with lead ingestion. This hypothesis is based on published studies showing elevated blood lead concentrations in subsistence hunter populations, retention of ammunition residues in the tissues of hunter-killed animals, and systemic, cognitive, and behavioral disorders associated with human lead body burdens once considered safe. Our objective was to determine the incidence and bioavailability of lead bullet fragments in hunter-killed venison, a widely-eaten food among hunters and their families. We radiographed 30 eviscerated carcasses of White-tailed Deer (Odocoileus virginianus) shot by hunters with standard lead-core, copper-jacketed bullets under normal hunting conditions. All carcasses showed metal fragments (geometric mean = 136 fragments, range = 15–409) and widespread fragment dispersion. We took each carcass to a separate meat processor and fluoroscopically scanned the resulting meat packages; fluoroscopy revealed metal fragments in the ground meat packages of 24 (80%) of the 30 deer; 32% of 234 ground meat packages contained at least one fragment. Fragments were identified as lead by ICP in 93% of 27 samples. Isotope ratios of lead in meat matched the ratios of bullets, and differed from background lead in bone. We fed fragment-containing venison to four pigs to test bioavailability; four controls received venison without fragments from the same deer. Mean blood lead concentrations in pigs peaked at 2.29 µg/dL (maximum 3.8 µg/dL) 2 days following ingestion of fragment-containing venison, significantly higher than the 0.63 µg/dL averaged by controls. We conclude that people risk exposure to bioavailable lead from bullet fragments when they eat venison from deer killed with standard lead-based rifle bullets and processed under normal procedures. At risk in the U.S. are some ten million hunters, their families, and low-income beneficiaries of

  9. Increased concanavalin A-induced suppressor cell activity in humans with occupational lead exposure

    SciTech Connect

    Cohen, N.; Modai, D.; Golik, A.; Weissgarten, J.; Peller, S.; Katz, A.; Averbukh, Z.; Shaked, U.

    1989-02-01

    E-rosette-forming cells (E-RFC), mitogen-induced blast transformation, OKT4+, OKT8+ cells, and their ratio were found to be normal in 10 subjects chronically exposed to lead with blood levels of 40-51 micrograms%. However, concanavalin A (Con A)-induced suppressor cell activity (SCA) in these subjects was significantly greater than in normal matched controls. The clinical relevance of this observation is not clear, but it may have some bearing on the various immunologic defects described in lead exposure.

  10. Lead Exposure during Early Human Development and DNA Methylation of Imprinted Gene Regulatory Elements in Adulthood

    PubMed Central

    Li, Yue; Xie, Changchun; Murphy, Susan K.; Skaar, David; Nye, Monica; Vidal, Adriana C.; Cecil, Kim M.; Dietrich, Kim N.; Puga, Alvaro; Jirtle, Randy L.; Hoyo, Cathrine

    2015-01-01

    Background: Lead exposure during early development causes neurodevelopmental disorders by unknown mechanisms. Epidemiologic studies have focused recently on determining associations between lead exposure and global DNA methylation; however, such approaches preclude the identification of loci that may alter human disease risk. Objectives: The objective of this study was to determine whether maternal, postnatal, and early childhood lead exposure can alter the differentially methylated regions (DMRs) that control the monoallelic expression of imprinted genes involved in metabolism, growth, and development. Methods: Questionnaire data and serial blood lead levels were obtained from 105 participants (64 females, 41 males) of the Cincinnati Lead Study from birth to 78 months. When participants were adults, we used Sequenom EpiTYPER assays to test peripheral blood DNA to quantify CpG methylation in peripheral blood leukocytes at DMRs of 22 human imprinted genes. Statistical analyses were conducted using linear regression. Results: Mean blood lead concentration from birth to 78 months was associated with a significant decrease in PEG3 DMR methylation (β = –0.0014; 95% CI: –0.0023, –0.0005, p = 0.002), stronger in males (β = –0.0024; 95% CI: –0.0038, –0.0009, p = 0.003) than in females (β = –0.0009; 95% CI: –0.0020, 0.0003, p = 0.1). Elevated mean childhood blood lead concentration was also associated with a significant decrease in IGF2/H19 (β = –0.0013; 95% CI: –0.0023, –0.0003, p = 0.01) DMR methylation, but primarily in females, (β = –0.0017; 95% CI: –0.0029, –0.0006, p = 0.005) rather than in males, (β = –0.0004; 95% CI: –0.0023, 0.0015, p = 0.7). Elevated blood lead concentration during the neonatal period was associated with higher PLAGL1/HYMAI DMR methylation regardless of sex (β = 0.0075; 95% CI: 0.0018, 0.0132, p = 0.01). The magnitude of associations between cumulative lead exposure and CpG methylation remained unaltered from

  11. Study of lead exposure to children residing near a lead–zinc mine

    PubMed Central

    Choudhari, Ranjana; Sathwara, N. G.; Shivgotra, V. K.; Patel, Shruti; Rathod, R. A.; Shaikh, Shagufta; Shaikh, M. Idrish; Dodia, Shaswat; Parikh, D. J.; Saiyed, H. N.

    2010-01-01

    This lead exposure study was conducted in a total of 452 school children in the age group of 9–14 years. Two hundred and ninety-eight exposed children came from the villages situated within a 2.5 km radius of the lead–zinc mine whereas the comparative group children were selected from the villages at least 10 km away from mine. Environmental monitoring study suggested that lead levels in air and water samples near the mining areas were within the Central Pollution Control Board prescribed standards. Lead levels in about 80% of the children were less than 10 μg/dl. Medical examination of all children did not show any signs related to lead toxicity but central nervous system-related symptoms, as reported by the subjects during medical examination, were found to be higher in the exposed group when compared with the comparative group. The values of physical growth parameters of the exposed group were comparable with that of the comparative group for both girls and boys. Hence, the physical growth of children was found to be unaffected by the observed level of lead exposure. To safeguard the health of the children residing near the mining area, various preventive and control measures were suggested. PMID:21120083

  12. Incidence of nephrolithiasis in relation to environmental exposure to lead and cadmium in a population study.

    PubMed

    Hara, Azusa; Yang, Wen-Yi; Petit, Thibault; Zhang, Zhen-Yu; Gu, Yu-Mei; Wei, Fang-Fei; Jacobs, Lotte; Odili, Augustine N; Thijs, Lutgarde; Nawrot, Tim S; Staessen, Jan A

    2016-02-01

    Whether environmental exposure to nephrotoxic agents that potentially interfere with calcium homeostasis, such as lead and cadmium, contribute to the incidence of nephrolithiasis needs further clarification. We investigated the relation between nephrolithiasis incidence and environmental lead and cadmium exposure in a general population. In 1302 participants randomly recruited from a Flemish population (50.9% women; mean age, 47.9 years), we obtained baseline measurements (1985-2005) of blood lead (BPb), blood cadmium (BCd), 24-h urinary cadmium (UCd) and covariables. We monitored the incidence of kidney stones until October 6, 2014. We used Cox regression to calculate multivariable-adjusted hazard ratios for nephrolithiasis. At baseline, geometric mean BPb, BCd and UCd was 0.29µmol/L, 9.0nmol/L, and 8.5nmol per 24h, respectively. Over 11.5 years (median), nephrolithiasis occurred in 40 people. Contrasting the low and top tertiles of the distributions, the sex- and age-standardized rates of nephrolithiasis expressed as events per 1000 person-years were 0.68 vs. 3.36 (p=0.0016) for BPb, 1.80 vs. 3.28 (p=0.11) for BCd, and 1.65 vs. 2.95 (p=0.28) for UCd. In continuous analysis, with adjustments applied for sex, age, serum magnesium, and 24-h urinary volume and calcium, the hazard ratios expressing the risk associated with a doubling of the exposure biomarkers were 1.35 (p=0.015) for BPb, 1.13 (p=0.22) for BCd, and 1.23 (p=0.070) for UCd. In conclusion, our results suggest that environmental lead exposure is a risk factor for nephrolithiasis in the general population. PMID:26613344

  13. Lead exposure of waterfowl ingesting Coeur d`Alene River Basin sediments

    SciTech Connect

    Beyer, W.N.; Morton, A.; Audet, D.J.; Campbell, J.K.; LeCaptain, L.

    1998-11-01

    Feces from tundra swans [Bygnus columbianus (Ord)], Canada geese [Branta canadensis (L.)], and mallards [Anas platrhynchos (L.)] were collected from the Coeur d`Alene River Basin and two reference areas in Idaho to estimate exposure to lead from mining activities and relate that exposure to the ingestion of contaminated sediments. The average acid-insoluble ash content of the feces, a measure of sediment ingestion, was 18% for Canada geese and tundra swans, and 12% for ducks. The 18% value corresponded to an estimated 9% sediment ingestion rate (dry weight). The 90th percentile for acid-insoluble ash in feces of tundra swans-corresponded to an estimated 22% sediment in the diet. The average lead concentration (dry weight) of tundra swan feces from all Coeur d`Alene River Basin wetlands sampled was 880 mg/kg, compared to 2.1 mg kg{sup {minus}1} from reference areas. the 90th percentile of lead in tundra swan feces from the Coeur d`Alene River Basin sites was 2700 mg kg{sup {minus}1}. Fecal lead concentrations of tundra swans were correlated with the acid-insoluble ash content of the feces. The very low lead concentrations in feces having low acid-insoluble ash contents established that the sediment was the primary source of the lead ingested by waterfowl. Sediment lead concentrations at 11 wetland sites were closely correlated with average fecal lead concentrations for all waterfowl, corrected for the average percent acid-insoluble ash in the feces.

  14. Gestational lead exposure selectively decreases retinal dopamine amacrine cells and dopamine content in adult mice

    SciTech Connect

    Fox, Donald A.; Hamilton, W. Ryan; Johnson, Jerry E.; Xiao, Weimin; Chaney, Shawntay; Mukherjee, Shradha; Miller, Diane B.; O'Callaghan, James P.

    2011-11-15

    Gestational lead exposure (GLE) produces supernormal scotopic electroretinograms (ERG) in children, monkeys and rats, and a novel retinal phenotype characterized by an increased number of rod photoreceptors and bipolar cells in adult mice and rats. Since the loss of dopaminergic amacrine cells (DA ACs) in GLE monkeys and rats contributes to supernormal ERGs, the retinal DA system was analyzed in mice following GLE. C57BL/6 female mice were exposed to low (27 ppm), moderate (55 ppm) or high (109 ppm) lead throughout gestation and until postnatal day 10 (PN10). Blood [Pb] in control, low-, moderate- and high-dose GLE was {<=} 1, {<=} 10, {approx} 25 and {approx} 40 {mu}g/dL, respectively, on PN10 and by PN30 all were {<=} 1 {mu}g/dL. At PN60, confocal-stereology studies used vertical sections and wholemounts to characterize tyrosine hydroxylase (TH) expression and the number of DA and other ACs. GLE dose-dependently and selectively decreased the number of TH-immunoreactive (IR) DA ACs and their synaptic plexus without affecting GABAergic, glycinergic or cholinergic ACs. Immunoblots and confocal revealed dose-dependent decreases in retinal TH protein expression and content, although monoamine oxidase-A protein and gene expression were unchanged. High-pressure liquid chromatography showed that GLE dose-dependently decreased retinal DA content, its metabolites and DA utilization/release. The mechanism of DA selective vulnerability is unknown. However, a GLE-induced loss/dysfunction of DA ACs during development could increase the number of rods and bipolar cells since DA helps regulate neuronal proliferation, whereas during adulthood it could produce ERG supernormality as well as altered circadian rhythms, dark/light adaptation and spatial contrast sensitivity. -- Highlights: Black-Right-Pointing-Pointer Peak [BPb] in control, low-, moderate- and high-dose newborn mice with gestational lead exposure: {<=} 1, {<=} 10, 25 and 40 {mu}g/dL Black

  15. Exposure of the mouse perinatal testis to radiation leads to hypospermia at sexual maturity.

    PubMed

    Forand, A; Messiaen, S; Habert, R; Bernardino-Sgherri, J

    2009-03-01

    The first round of mouse spermatogenesis begins from 3 to 4 days after birth through differentiation of gonocytes into spermatogonial-stem cells and type A spermatogonia. Consequently, this step of differentiation may determine generation of the original population of stem cells and the fertility potential of the adult mouse. We aimed to determine the effect of perinatal exposure to ionizing radiation on the testis at the end of the first wave of spermatogenesis and at sexual maturity. Our results show that, radiation sensitivity of the testis substantially decreases from late foetal life to the end of the first week after birth. In addition, partial or full recovery from radiation induced testicular weight loss occurred between the first round of spermatogenesis and sexual maturity, and this was associated with the stimulation of spermatogonial proliferation. Exposure of mice at 17.5 days after conception or at 1 day after birth to gamma-rays decreased the sperm counts at sexual maturity, while exposure of 8 day-old mice had no effect. This suggests that irradiation of late foetal or early neonatal testes has a direct impact on the generation of the neonatal spermatogonial-stem cell pool. PMID:19109333

  16. Human exposure pathways of heavy metals in a lead-zinc mining area, Jiangsu Province, China.

    PubMed

    Qu, Chang-Sheng; Ma, Zong-Wei; Yang, Jin; Liu, Yang; Bi, Jun; Huang, Lei

    2012-01-01

    Heavy metal pollution is becoming a serious issue in developing countries such as China, and the public is increasingly aware of its adverse health impacts in recent years. We assessed the potential health risks in a lead-zinc mining area and attempted to identify the key exposure pathways. We evaluated the spatial distributions of personal exposure using indigenous exposure factors and field monitoring results of water, soil, food, and indoor and outdoor air samples. The risks posed by 10 metals and the contribution of inhalation, ingestion and dermal contact pathways to these risks were estimated. Human hair samples were also analyzed to indicate the exposure level in the human body. Our results show that heavy metal pollution may pose high potential health risks to local residents, especially in the village closest to the mine (V1), mainly due to Pb, Cd and Hg. Correspondingly, the residents in V1 had higher Pb (8.14 mg/kg) levels in hair than those in the other two villages. Most of the estimated risks came from soil, the intake of self-produced vegetables and indoor air inhalation. This study highlights the importance of site-specific multipathway health risk assessments in studying heavy-metal exposures in China. PMID:23152752

  17. Lead exposure in pheochromocytoma cells induces persistent changes in amyloid precursor protein gene methylation patterns.

    PubMed

    Li, Yuan-Yuan; Chen, Tian; Wan, Yanjian; Xu, Shun-qing

    2012-08-01

    It has been suggested that lead (Pb) exposure in early life may increase amyloid precursor protein (APP) expression and promote the pathogenesis of Alzheimer's disease in old age. The current study examined whether the DNA methylation patterns of APP gene in rat pheochromocytoma (PC12) cells changed after Pb acetate exposure. Undifferentiated PC12 cells were exposed to three doses of Pb acetate (50, 250, and 500 nM) and one control for 2 days or 1 week. The methylation patterns of APP promoter and global DNA methylation were analyzed. The DNA methyltransferase 1 (DNMT1) expression and the level of amyloid β peptide (Aβ) were also investigated. The results showed that the exposure of the three concentrations of Pb acetate could make the APP promoter hypomethylated. The global DNA methylation level and the expression of DNMT1 were changed in the 500 nM group after 2 days exposure and in the 250 and 500 nM group after 7 days exposure. Thus, Pb may exert neurotoxic effects through mechanisms that alter the global and promoter methylation patterns of APP gene. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012. PMID:22764079

  18. Human Exposure Pathways of Heavy Metals in a Lead-Zinc Mining Area, Jiangsu Province, China

    PubMed Central

    Qu, Chang-Sheng; Ma, Zong-Wei; Yang, Jin; Liu, Yang; Bi, Jun; Huang, Lei

    2012-01-01

    Heavy metal pollution is becoming a serious issue in developing countries such as China, and the public is increasingly aware of its adverse health impacts in recent years. We assessed the potential health risks in a lead-zinc mining area and attempted to identify the key exposure pathways. We evaluated the spatial distributions of personal exposure using indigenous exposure factors and field monitoring results of water, soil, food, and indoor and outdoor air samples. The risks posed by 10 metals and the contribution of inhalation, ingestion and dermal contact pathways to these risks were estimated. Human hair samples were also analyzed to indicate the exposure level in the human body. Our results show that heavy metal pollution may pose high potential health risks to local residents, especially in the village closest to the mine (V1), mainly due to Pb, Cd and Hg. Correspondingly, the residents in V1 had higher Pb (8.14 mg/kg) levels in hair than those in the other two villages. Most of the estimated risks came from soil, the intake of self-produced vegetables and indoor air inhalation. This study highlights the importance of site-specific multipathway health risk assessments in studying heavy-metal exposures in China. PMID:23152752

  19. Dorchester Lead-Safe Yard project: a pilot program to demonstrate low-cost, on-site techniques to reduce exposure to lead-contaminated soil.

    PubMed

    Hynes, H P; Maxfield, R; Carroll, P; Hillger, R

    2001-03-01

    Despite a general reduction in blood lead levels in children after lead was banned in gasoline and paint, lead poisoning remains an important health problem in many older urban areas. One factor that increases risk in these places is the high levels of lead in certain residential areas. A major intervention study found that reducing lead levels in urban soils results in a reduction in exposed children's blood lead levels. Removing lead from inner-city soils or reducing exposures to lead-contaminated soils typically is expensive, technologically challenging, or beyond the ability of low-income households to undertake. This project, in conjunction with residents and community-based institutions, developed a series of in situ, low-cost, low-technology measures that worked to reduce the exposure to lead-contaminated soils in one Boston, Massachusetts, neighborhood. The project demonstrated several important results. Government, universities, residents, and community based organizations can work together effectively to reduce exposures to lead in soil. Lead-contaminated soil can be mitigated at a fraction of the cost of conventional methods in ways that increase the ability of residents, community health centers, and others to have a positive impact on their neighborhoods. A lead-safe yard program can be replicated and institutionalized by municipal home de-leading programs and other community organizations. PMID:11368198

  20. Optically stimulated luminescence (OSL) as a chronometer for surface exposure dating

    NASA Astrophysics Data System (ADS)

    Sohbati, Reza; Murray, Andrew S.; Chapot, Melissa S.; Jain, Mayank; Pederson, Joel

    2012-09-01

    We pioneer a technique of surface-exposure dating based upon the characteristic form of an optically stimulated luminescence (OSL) bleaching profile beneath a rock surface; this evolves as a function of depth and time. As a field illustration of this new method, the maximum age of a premier example of Barrier Canyon Style (BCS) rock art in Canyonlands National Park, Utah, USA, is constrained. The natural OSL signal from quartz grains is measured from the surface to a depth of >10 mm in three different rock samples of the Jurassic Navajo Sandstone. Two samples are from talus with unknown daylight exposure histories; one of these samples was exposed at the time of sampling and one was buried and no longer light exposed. A third sample is known to have been first exposed 80 years ago and was still exposed at the time of sampling. First, the OSL-depth profile of the known-age sample is modeled to estimate material-dependent and environmental parameters. These parameters are then used to fit the model to the corresponding data for the samples of unknown exposure history. From these fits we calculate that the buried sample was light exposed for ˜700 years before burial and that the unburied sample has been exposed for ˜120 years. The shielded surface of the buried talus sample is decorated with rock art; this rock fell from the adjacent Great Gallery panel. Related research using conventional OSL dating suggests that this rockfall event occurred ˜900 years ago, and so we deduce that the rock art must have been created between ˜1600 and 900 years ago. Our results are the first credible estimates of exposure ages based on luminescence bleaching profiles. The strength of this novel OSL method is its ability to establish both ongoing and prior exposure times, at decadal to millennial timescales or perhaps longer (depending on the environmental dose rate) even for material subsequently buried. This has considerable potential in many archeological, geological and geo

  1. In vivo measurements of lead in bone at four anatomical sites: long term occupational and consequent endogenous exposure.

    PubMed Central

    Erkkilä, J; Armstrong, R; Riihimäki, V; Chettle, D R; Paakkari, A; Scott, M; Somervaille, L; Starck, J; Kock, B; Aitio, A

    1992-01-01

    Measurements of bone lead concentrations in the tibia, wrist, sternum, and calcaneus were performed in vivo by x ray fluorescence on active and retired lead workers from two acid battery factories, office personnel in the two factories under study, and control subjects. Altogether 171 persons were included. Lead concentrations in the tibia and ulna (representative of cortical bone) appeared to behave similarly with respect to time but the ulnar measurement was much less precise. In an analogous fashion, lead in the calcaneus and sternum (representative of trabecular bone) behaved in the same way, but sternal measurement was less precise. Groups occupationally exposed to lead were well separated from the office workers and the controls on the basis of calculated skeletal lead burdens, whereas the differences in blood lead concentrations were not as great, suggesting that the use of concentrations of lead in blood might seriously underestimate lead body burden. The exposures encountered in the study were modest, however. The mean blood lead value among active lead workers was 1.45 mumol l-1 and the mean tibial lead concentration 21.1 micrograms (g bone mineral)-1. The kinetics of lead in the tibia appeared to be noticeably different from that in the calcaneus. Tibial lead concentration increased consistently both as a function of intensity of exposure and of duration of exposure. Calcaneal lead concentration, by contrast, was strongly dependent on the intensity rather than duration of exposure. This indicated that the biological half life of lead in calcaneus was less than the seven to eight year periods into which the duration of exposure was split. Findings for retired workers clearly showed that endogenous exposure to lead arising from skeletal burdens accumulated over a working lifetime can easily produce the dominant contribution to systemic lead concentrations once occupational exposure has ceased. PMID:1390269

  2. Neurochemical and neurobehavioral effects of low lead exposure on the developing brain.

    PubMed

    Bijoor, Anita R; Sudha, S; Venkatesh, T

    2012-04-01

    Lead is found in small but appreciable quantities in air, soil drinking water and food. Exposure to such amounts of lead does not cause acute lead toxicity, but produces subtle effects, particularly in children. The CDC advocates "safe" or "acceptable" levels of blood lead up to 10 μg/dl, while OSHA declares blood lead levels up to 40 μg/dl as "safe" or "acceptable" in the occupationally exposed. The objective of the study was to see if blood levels considered "safe" can cause changes in the biogenic neurotransmitters in the developing brain which may cause neurobehavioral defects like hyperactivity and other cognitive disorders. Albino Wistar rats were divided into the control and lead-treated groups. The control group was given unleaded water, while the lead-treated group was fed with 50 ppm lead acetate in drinking water. On day 45 the animals were subjected to a passive avoidance test, their blood analysed for ZPP and lead. They were then sacrificed and the neurotransmitters-Norepinephrine (NE) and its metabolite-methoxyhydroxyphenylglycol (MHPG) estimated in the brain areas associated with learning and memory-the frontal cortex, hippocampus and the striatum by HPLC-ECD. Our results showed significant increases in blood lead, NE and MHPG, while ZPP increase was insignificant. The rats showed neurobehavioral abnormalities as assessed by the passive avoidance test. We concluded that low blood levels of lead cannot be considered "safe" or "acceptable" as it causes neurotransmitter alterations. Increased NE turnover is implicated in hyperactivity disorders such as ADHD and Tourette syndrome. PMID:23543765

  3. An optically stimulated luminescence dosimeter for measuring patient exposure from imaging guidance procedures.

    PubMed

    Ding, George X; Malcolm, Arnold W

    2013-09-01

    There is a growing interest in patient exposure resulting from an x-ray imaging procedure used in image-guided radiation therapy. This study explores a feasibility to use a commercially available optically stimulated luminescence (OSL) dosimeter, nanoDot, for estimating imaging radiation exposure to patients. The kilovoltage x-ray sources used for kV-cone-beam CT (CBCT) imaging acquisition procedures were from a Varian on-board imager (OBI) image system. An ionization chamber was used to determine the energy response of nanoDot dosimeters. The chamber calibration factors for x-ray beam quality specified by half-value layer were obtained from an Accredited Dosimetry Calibration Laboratory. The Monte Carlo calculated dose distributions were used to validate the dose distributions measured by using the nanoDot dosimeters in phantom and in vivo. The range of the energy correction factors for the nanoDot as a function of photon energy and bow-tie filters was found to be 0.88-1.13 for different kVp and bow-tie filters. Measurement uncertainties of nanoDot were approximately 2-4% after applying the energy correction factors. The tests of nanoDot placed on a RANDO phantom and on patient's skin showed consistent results. The nanoDot is suitable dosimeter for in vivo dosimetry due to its small size and manageable energy dependence. The dosimeter placed on a patient's skin has potential to serve as an experimental method to monitor and to estimate patient exposure resulting from a kilovoltage x-ray imaging procedure. Due to its large variation in energy response, nanoDot is not suitable to measure radiation doses resulting from mixed beams of megavoltage therapeutic and kilovoltage imaging radiations. PMID:23920245

  4. An optically stimulated luminescence dosimeter for measuring patient exposure from imaging guidance procedures

    NASA Astrophysics Data System (ADS)

    Ding, George X.; Malcolm, Arnold W.

    2013-09-01

    There is a growing interest in patient exposure resulting from an x-ray imaging procedure used in image-guided radiation therapy. This study explores a feasibility to use a commercially available optically stimulated luminescence (OSL) dosimeter, nanoDot, for estimating imaging radiation exposure to patients. The kilovoltage x-ray sources used for kV-cone-beam CT (CBCT) imaging acquisition procedures were from a Varian on-board imager (OBI) image system. An ionization chamber was used to determine the energy response of nanoDot dosimeters. The chamber calibration factors for x-ray beam quality specified by half-value layer were obtained from an Accredited Dosimetry Calibration Laboratory. The Monte Carlo calculated dose distributions were used to validate the dose distributions measured by using the nanoDot dosimeters in phantom and in vivo. The range of the energy correction factors for the nanoDot as a function of photon energy and bow-tie filters was found to be 0.88-1.13 for different kVp and bow-tie filters. Measurement uncertainties of nanoDot were approximately 2-4% after applying the energy correction factors. The tests of nanoDot placed on a RANDO phantom and on patient's skin showed consistent results. The nanoDot is suitable dosimeter for in vivo dosimetry due to its small size and manageable energy dependence. The dosimeter placed on a patient's skin has potential to serve as an experimental method to monitor and to estimate patient exposure resulting from a kilovoltage x-ray imaging procedure. Due to its large variation in energy response, nanoDot is not suitable to measure radiation doses resulting from mixed beams of megavoltage therapeutic and kilovoltage imaging radiations.

  5. Tracing fetal and childhood exposure to lead using isotope analysis of deciduous teeth.

    PubMed

    Shepherd, Thomas J; Dirks, Wendy; Roberts, Nick M W; Patel, Jaiminkumar G; Hodgson, Susan; Pless-Mulloli, Tanja; Walton, Pamela; Parrish, Randall R

    2016-04-01

    We report progress in using the isotopic composition and concentration of Pb in the dentine and enamel of deciduous teeth to provide a high resolution time frame of exposure to Pb during fetal development and early childhood. Isotope measurements (total Pb and (208)Pb/(206)Pb, (207)Pb/(206)Pb ratios) were acquired by laser ablation inductively coupled mass spectrometry at contiguous 100 micron intervals across thin sections of the teeth; from the outer enamel surface to the pulp cavity. Teeth samples (n=10) were selected from two cohorts of children, aged 5-8 years, living in NE England. By integrating the isotope data with histological analysis of the teeth, using the daily incremental lines in dentine, we were able to assign true estimated ages to each ablation point (first 2-3 years for molars, first 1-2 years for incisors+pre-natal growth). Significant differences were observed in the isotope composition and concentration of Pb between children, reflecting differences in the timing and sources of exposure during early childhood. Those born in 2000, after the withdrawal of leaded petrol in 1999, have the lowest dentine Pb levels (<0.2µgPb/g) with (208)Pb/(206)Pb (mean ±2σ: 2.126-2.079) (208)Pb/(206)Pb (mean ±2σ: 0.879-0.856) ratios that correlate very closely with modern day Western European industrial aerosols (PM10, PM2.5) suggesting that diffuse airborne pollution was probably the primary source and exposure pathway. Legacy lead, if present, is insignificant. For those born in 1997, dentine lead levels are typically higher (>0.4µgPb/g) with (208)Pb/(206)Pb (mean ±2σ: 2.145-2.117) (208)Pb/(206)Pb (mean ±2σ: 0.898-0.882) ratios that can be modelled as a binary mix between industrial aerosols and leaded petrol emissions. Short duration, high intensity exposure events (1-2 months) were readily identified, together with evidence that dentine provides a good proxy for childhood changes in the isotope composition of blood Pb. Our pilot study confirms that

  6. Exposure of children to lead and cadmium from a mining area of Brazil.

    PubMed

    Paoliello, Monica Maria Bastos; De Capitani, Eduardo Mello; da Cunha, Fernanda Gonçalves; Matsuo, Tiemi; Carvalho, Maria de Fátima; Sakuma, Alice; Figueiredo, Bernardino Ribeiro

    2002-02-01

    During the past 50 years the Ribeira river valley, in the southern part of the state of São Paulo, Brazil, had been under the influence of the full activity of a huge lead refinery and mine working by the side of the river. The plant completely stopped all kinds of industrial activities at the end of 1995, and part of the worker population and their families still remain living nearby in small communities. The objective of the study was to assess the exposure of children to lead and cadmium in these areas, where residual environmental contamination from the past industrial activity still exists. Blood samples of 295 children aged 7 to 14 years, residing in rural and urban areas around the mine and the refinery, were collected. A questionnaire was given to gather information on food habits, leisure activities, father's past employment, current and former residential places, and other variables. Blood lead and cadmium concentrations were analyzed by graphite furnace atomic absorption spectrometry using Zeeman background correction. Cadmium values obtained in this population were mostly below established quantification limits (0.5 microg/dl). The median of blood lead level (BLL) obtained in children living close to the lead refinery was 11.25 microg/dl, and the median in other mining regions far from the refinery was 4.4 microg/dl. Logistic regression analysis was conducted to examine the independent contribution of selected variables in predicting BLL in these children. The following variables showed significant association with high BLL: residential area close to the lead refinery [odds ratio (OR)=10.38 (95% confidence interval (Cl)=4.86-23.25)], former father's occupational lead exposure [OR=4.07 (95% Cl=1.82-9.24)], and male gender [OR=2.60 (95% Cl=1.24-5.62)]. PMID:11908937

  7. Paraoccupational exposures to lead and tin carried by electric-cable splicers

    SciTech Connect

    Rinehart, R.D.; Yanagisawa, Y. )

    1993-10-01

    To test the hypothesis that electric-cable splicers contaminate their homes with lead and tin, nine splicers were matched with nine of their neighbors. House dust samples were collected in two areas within each home: a laundry room/dirty clothes area, and a composite sample from other areas in the house. Samples were analyzed by energy dispersive X-ray fluorescence for lead and tin (tin is a tracer to the occupational source of lead). The difference in the geometric mean lead concentrations in the laundry areas between the splicers' and neighbors' homes (1021 ppm and 390 ppm) was statistically significant (p < 0.025). The difference in concentrations from the other areas of the house (585 ppm and 329 ppm) was also significant (p < 0.05). Tin concentrations in house dust were very different between the two groups (p < 0.0005), suggesting that electric-cable splicers were contaminating their homes with lead and tin from work. Recommendations are included to prevent paraoccupational lead exposures by eliminating the pathways into the home. Another recommendation suggests that blood-lead levels be screened in children under the age of seven who live with electric-cable splicers.

  8. Changes in exposure temperature lead to changes in pesticide toxicity to earthworms: A preliminary study.

    PubMed

    Velki, Mirna; Ečimović, Sandra

    2015-11-01

    The occurring climate changes will have direct consequences to all ecosystems, including the soil ecosystems. The effects of climate change include, among other, the changes in temperature and greater frequency and intensity of extreme weather conditions. Temperature is an important factor in ecotoxicological investigations since it can act as a stressor and influence the physiological status of organisms, as well as affect the fate and transport of pollutants present in the environment. However, most of so far conducted (eco)toxicological investigations neglected the possible effects of temperature and focused solely on the effects of toxicants on organisms. Considering that temperature can contribute to the toxicity of pollutants, it is of immense importance to investigate whether the change in the exposure temperature will impact the strength of the toxic effects of pollutants present in soil ecosystems. Therefore, in the present study the toxicity of several commonly used pesticides to earthworms was assessed under different exposure temperatures (15, 20 and 25°C). The results showed that changes in exposure temperature lead to changes in susceptibility of earthworms to particular pesticides. Namely, exposures to the same pesticide concentration at different temperatures lead to different toxicity responses. Increase in exposure temperature in most cases caused increase in toxicity, whereas decrease in temperature mostly caused decrease in toxicity. This preliminary study points to need for an in-depth investigation of mechanisms by which temperature affects the toxicity of pesticides and also provides important data for future research on the effects of temperature change on the soil ecosystems. PMID:26436694

  9. Studies of lead exposure on reproductive system: a review of work in China.

    PubMed

    Xuezhi, J; Youxin, L; Yilan, W

    1992-09-01

    This paper, based on a review of a series studies conducted in China from 1978 through 1991, describes the possible links between low level lead exposure and the adverse effects on reproductive system. Effects on menstrual status and pregnancy outcome manifested mainly as higher prevalences of menstrual disturbance, spontaneous abortion and threatened abortion in exposed females. Transfer of lead via placenta and human milk was shown by higher lead levels in milk and blood of infant. Impairment of male reproductive function was observed as decreased volume of ejaculation, prolonged latency of semen melting, reduced total sperm count and alive spermatozoa, retarded sperm activity as well as lowered density of semen fluid in exposed male workers with Pb-B over 40 micrograms.dl-1. In addition, poorer performance of WISC-R test was revealed in children with Pb-B level over 30 micrograms.dl-1, and retarded physical development was observed in children with Pb-B over 20 micrograms.dl-1. Therefore, health surveillance including the assessment of adverse effects on reproductive system of both female and male lead exposed workers should not be ignored. Furthermore, safety exposure limit of work place, particularly for female workers of child-bearing age, should be developed. PMID:1449662

  10. Cadmium, lead, and mercury exposure assessment among croatian consumers of free-living game.

    PubMed

    Lazarus, Maja; Prevendar Crnić, Andreja; Bilandžić, Nina; Kusak, Josip; Reljić, Slaven

    2014-09-01

    Free-living game can be an important source of dietary cadmium and lead; the question is whether exposure to these two elements is such that it might cause adverse health effects in the consumers. The aim of this study was to estimate dietary exposure to cadmium, lead, and mercury from free-living big game (fallow deer, roe deer, red deer, wild boar, and brown bear), and to mercury from small game (pheasant and hare), hunted in Croatia from 1990 to 2012. The exposure assessment was based on available literature data and our own measurements of metal levels in the tissues of the game, by taking into account different consumption frequencies (four times a year, once a month and once a week). Exposure was expressed as percentage of (provisional) tolerable weekly intake [(P)TWI] values set by the European Food Safety Authority (EFSA). Consumption of game meat (0.002-0.5 % PTWI) and liver (0.005-6 % PTWI) assumed for the general population (four times a year) does not pose a health risk to consumers from the general population, nor does monthly (0.02-6 % PTWI) and weekly (0.1-24 % PTWI) consumption of game meat. However, because of the high percentage of free-living game liver and kidney samples exceeding the legislative limits for cadmium (2-99 %) and lead (1-82 %), people should keep the consumption of certain game species' offal as low as possible. Children and pregnant and lactating women should avoid eating game offal altogether. Free-living game liver could be an important source of cadmium if consumed on a monthly basis (3-74 % TWI), and if consumed weekly (11-297 % TWI), it could even give rise to toxicological concern. PMID:25205692

  11. Exposure to PM2.5 and Blood Lead Level in Two Populations in Ulaanbaatar, Mongolia

    PubMed Central

    Enkhbat, Undarmaa; Rule, Ana M.; Resnick, Carol; Ochir, Chimedsuren; Olkhanud, Purevdorj; Williams, D’Ann L.

    2016-01-01

    Approximately 60% of the households in Ulaanbaatar live in gers (a traditional Mongolian dwelling) in districts outside the legal limits of the city, without access to basic infrastructure, such as water, sewage systems, central heating, and paved roads, in contrast to apartment residents. This stark difference in living conditions creates different public health challenges for Ulaanbaatar residents. Through this research study we aim to test our hypothesis that women living in gers burning coal in traditional stoves for cooking and heating during the winter are exposed to higher concentrations of airborne PM2.5 than women living in apartments in Ulaanbaatar, Mongolia, and this exposure may include exposures to lead in coal with effects on blood lead levels. This cross-sectional study recruited a total of 50 women, 40–60 years of age, from these two settings. Air sampling was carried out during peak cooking and heating times, 5:00 p.m.–11:00 p.m., using a direct-reading instrument (TSI SidePak™) and integrated polytetrafluoroethylene (PTFE) filters using the SKC Personal Environmental Monitor. Blood lead level (BLL) was measured using a LeadCare II rapid field test method. In our study population, measured PM2.5 geometric mean (GM) concentrations using the SidePak™ in the apartment group was 31.5 (95% CI:17–99) μg/m3, and 100 (95% CI: 67–187) μg/m3 in ger households (p < 0.001). The GM integrated gravimetric PM2.5 concentrations in the apartment group were 52.8 (95% CI: 39–297) μg/m3 and 127.8 (95% CI: 86–190) μg/m3 in ger households (p = 0.004). The correlation coefficient for the SidePak™ PM2.5 concentrations and filter based PM2.5 concentrations was r = 0.72 (p < 0.001). Blood Lead Levels were not statistically significant different between apartment residents and ger residents (p = 0.15). The BLL is statistically significant different (p = 0.01) when stratified by length of exposures outside of the home. This statistically significant

  12. Exposure to PM2.5 and Blood Lead Level in Two Populations in Ulaanbaatar, Mongolia.

    PubMed

    Enkhbat, Undarmaa; Rule, Ana M; Resnick, Carol; Ochir, Chimedsuren; Olkhanud, Purevdorj; Williams, D'Ann L

    2016-02-01

    Approximately 60% of the households in Ulaanbaatar live in gers (a traditional Mongolian dwelling) in districts outside the legal limits of the city, without access to basic infrastructure, such as water, sewage systems, central heating, and paved roads, in contrast to apartment residents. This stark difference in living conditions creates different public health challenges for Ulaanbaatar residents. Through this research study we aim to test our hypothesis that women living in gers burning coal in traditional stoves for cooking and heating during the winter are exposed to higher concentrations of airborne PM2.5 than women living in apartments in Ulaanbaatar, Mongolia, and this exposure may include exposures to lead in coal with effects on blood lead levels. This cross-sectional study recruited a total of 50 women, 40-60 years of age, from these two settings. Air sampling was carried out during peak cooking and heating times, 5:00 p.m.-11:00 p.m., using a direct-reading instrument (TSI SidePak™) and integrated polytetrafluoroethylene (PTFE) filters using the SKC Personal Environmental Monitor. Blood lead level (BLL) was measured using a LeadCare II rapid field test method. In our study population, measured PM2.5 geometric mean (GM) concentrations using the SidePak™ in the apartment group was 31.5 (95% CI:17-99) μg/m³, and 100 (95% CI: 67-187) μg/m³ in ger households (p < 0.001). The GM integrated gravimetric PM2.5 concentrations in the apartment group were 52.8 (95% CI: 39-297) μg/m³ and 127.8 (95% CI: 86-190) μg/m³ in ger households (p = 0.004). The correlation coefficient for the SidePak™ PM2.5 concentrations and filter based PM2.5 concentrations was r = 0.72 (p < 0.001). Blood Lead Levels were not statistically significant different between apartment residents and ger residents (p = 0.15). The BLL is statistically significant different (p = 0.01) when stratified by length of exposures outside of the home. This statistically significant difference

  13. Get the Lead Out: Facts about Childhood Lead Poisoning [and] Housekeeping Tips To Reduce Lead Exposure [and] Nutrition and Lead Poisoning [and] The Medical Consequences of Lead Poisoning [and] Lead Poisoning for Health Care Providers.

    ERIC Educational Resources Information Center

    Illinois State Dept. of Public Health, Springfield.

    This document is comprised of five fact sheets from the Illinois Department of Public Health regarding childhood lead poisoning. Recent studies claim that childhood lead poisoning can contribute to problems later in life, such as academic failure, juvenile delinquency, and high blood pressure. Directed to parents, caregivers, and health care…

  14. Lead Exposure Disrupts Global DNA Methylation in Human Embryonic Stem Cells and Alters Their Neuronal Differentiation

    PubMed Central

    Senut, Marie-Claude; Sen, Arko; Cingolani, Pablo; Shaik, Asra; Land, Susan J.; Ruden, Douglas M.

    2014-01-01

    Exposure to lead (Pb) during childhood can result in learning disabilities and behavioral problems. Although described in animal models, whether Pb exposure also alters neuronal differentiation in the developing brains of exposed children is unknown. Here, we investigated the effects of physiologically relevant concentrations of Pb (from 0.4 to 1.9μM) on the capacity of human embryonic stem cells (hESCs) to progress to a neuronal fate. We found that neither acute nor chronic exposure to Pb prevented hESCs from generating neural progenitor cells (NPCs). NPCs derived from hESCs chronically exposed to 1.9μM Pb throughout the neural differentiation process generated 2.5 times more TUJ1-positive neurons than those derived from control hESCs. Pb exposure of hESCs during the stage of neural rosette formation resulted in a significant decrease in the expression levels of the neural marker genes PAX6 and MSI1. Furthermore, the resulting NPCs differentiated into neurons with shorter neurites and less branching than control neurons, as assessed by Sholl analysis. DNA methylation studies of control, acutely treated hESCs and NPCs derived from chronically exposed hESCs using the Illumina HumanMethylation450 BeadChip demonstrated that Pb exposure induced changes in the methylation status of genes involved in neurogenetic signaling pathways. In summary, our study shows that exposure to Pb subtly alters the neuronal differentiation of exposed hESCs and that these changes could be partly mediated by modifications in the DNA methylation status of genes crucial to brain development. PMID:24519525

  15. Lead exposure disrupts global DNA methylation in human embryonic stem cells and alters their neuronal differentiation.

    PubMed

    Senut, Marie-Claude; Sen, Arko; Cingolani, Pablo; Shaik, Asra; Land, Susan J; Ruden, Douglas M

    2014-05-01

    Exposure to lead (Pb) during childhood can result in learning disabilities and behavioral problems. Although described in animal models, whether Pb exposure also alters neuronal differentiation in the developing brains of exposed children is unknown. Here, we investigated the effects of physiologically relevant concentrations of Pb (from 0.4 to 1.9μM) on the capacity of human embryonic stem cells (hESCs) to progress to a neuronal fate. We found that neither acute nor chronic exposure to Pb prevented hESCs from generating neural progenitor cells (NPCs). NPCs derived from hESCs chronically exposed to 1.9μM Pb throughout the neural differentiation process generated 2.5 times more TUJ1-positive neurons than those derived from control hESCs. Pb exposure of hESCs during the stage of neural rosette formation resulted in a significant decrease in the expression levels of the neural marker genes PAX6 and MSI1. Furthermore, the resulting NPCs differentiated into neurons with shorter neurites and less branching than control neurons, as assessed by Sholl analysis. DNA methylation studies of control, acutely treated hESCs and NPCs derived from chronically exposed hESCs using the Illumina HumanMethylation450 BeadChip demonstrated that Pb exposure induced changes in the methylation status of genes involved in neurogenetic signaling pathways. In summary, our study shows that exposure to Pb subtly alters the neuronal differentiation of exposed hESCs and that these changes could be partly mediated by modifications in the DNA methylation status of genes crucial to brain development. PMID:24519525

  16. Exposure to sodium butyrate leads to functional downregulation of calcium-activated potassium channels in human airway epithelial cells.

    PubMed

    Roy, Jeremy; Denovan-Wright, Eileen M; Linsdell, Paul; Cowley, Elizabeth A

    2006-11-01

    Cystic fibrosis (CF) is caused by genetic mutations that lead to dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel. The most common mutation, DeltaF508, causes inefficient trafficking of mutant CFTR protein from the endoplasmic reticulum to the cell membrane. Therapeutic efforts have been aimed at increasing the level of DeltaF508-CFTR protein in the membrane using agents such as sodium butyrate. In this study, we investigated the effects of culturing a human airway epithelial cell line, Calu-3, in the presence of 5 mM sodium butyrate. Within 24 h, butyrate exposure caused a significant decrease in the basal, as well as Ca(2+)-activated, anion secretion by Calu-3 cell monolayers, determined by the change in transepithelial short-circuit current in response to the Ca(2+)-elevating agent thapsigargin. The secretory response to 1-ethyl-2-benzimidazolinone, an activator of the basolateral Ca(2+)-activated K(+) channel KCNN4, was similarly reduced by butyrate treatment. Quantitative PCR revealed that these functional effects were associated with dramatic decreases in mRNA for both KCNN4 and CFTR. Furthermore, the KCNQ1 K(+) channel was upregulated after butyrate treatment. We suggest that prolonged exposure to sodium butyrate downregulates the expression of both KCNN4 and CFTR, leading to a functional loss of Ca(2+)-activated anion secretion. Thus, butyrate may inhibit, rather than stimulate, the anion secretory capacity of human epithelial cells that express wild-type CFTR, particularly in tissues that normally exhibit robust Ca(2+)-activated secretion. PMID:17047984

  17. A Meta-Analysis of Observational Studies of the Association Between Chronic Occupational Exposure to Lead and Amyotrophic Lateral Sclerosis

    PubMed Central

    Gomes, James; Cashman, Neil R.; Little, Julian; Krewski, Daniel

    2014-01-01

    Objective: The association between occupational exposure to lead and amyotrophic lateral sclerosis (ALS) was examined through systematic review and meta-analyses of relevant epidemiological studies and reported according to PRISMA guidelines. Methods: Relevant studies were searched in multiple bibliographic databases through September 2013; additional articles were tracked through PubMed until submission. All records were screened in DistillerSR, and the data extracted from included articles were synthesized with meta-analysis. Results: The risk of developing ALS among individuals with a history of exposure to lead was almost doubled (odds ratio, 1.81; 95% confidence interval, 1.39 to 2.36) on the basis of nine included case-control studies with specific lead exposure information, with no apparent heterogeneity across included studies (I2 = 14%). The attributable risk of ALS because of exposure to lead was estimated to be 5%. Conclusions: Previous exposure to lead may be a risk factor for ALS. PMID:25479292

  18. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration

    PubMed Central

    Clunes, Lucy A.; Davies, Catrin M.; Coakley, Raymond D.; Aleksandrov, Andrei A.; Henderson, Ashley G.; Zeman, Kirby L.; Worthington, Erin N.; Gentzsch, Martina; Kreda, Silvia M.; Cholon, Deborah; Bennett, William D.; Riordan, John R.; Boucher, Richard C.; Tarran, Robert

    2012-01-01

    Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB.—Clunes, L. A., Davies, C. M., Coakley, R. D., Aleksandrov, A. A., Henderson, A. G., Zeman, K. L., Worthington, E. N., Gentzsch, M., Kreda, S. M., Cholon, D., Bennett, W. D., Riordan, J. R., Boucher, R. C., Tarran, R. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration. PMID:21990373

  19. Lead exposure in children: levels in blood, prevalence of intoxication and related factors.

    PubMed

    Solé, E; Ballabriga, A; Domínguez, C

    1998-09-01

    Lead is a highly toxic metal, the main source of which is contamination from combustion of unleaded petrol. The aims of this work were to detect the degree of lead exposure in a large sample of children; determine the relationship between blood lead levels (BPb) and age, sex, habitat and season of the year; and correlate BPb with zinc protoporphyrin (ZPP) values. A cross-sectional study was carried out. Blood from routine extractions drawn at our centre was used. BPb and ZPP were measured by atomic absorption spectrophotometry and haematofluorimetry, respectively. We analysed 1158 blood samples from children. BPb (mean +/- SEM): 0.22 +/- 0.04 mumol l-1. Correlation BPb-age: BPb = 0.19 + 0.086 x age (months), r = 0.129, P < 0.0001. BPb was greater in boys (0.23 +/- 0.007 versus 0.20 +/- 0.006 mumol l-1, P < 0.0002). No differences were observed between habitats (urban versus rural). BPb were higher in the warm months (0.24 +/- 0.013 versus 0.21 +/- 0.007 mumol l-1, P < 0.0001). Prevalence of lead intoxication (BPb > 0.48 mumol l-1) was 4.2%. No differences in prevalence were found among the different groups. The correlation between BPb and ZPP showed r = 0.0969, P = 0.0024. Utility for screening: sensitivity of 53.7% and specificity of 59.3% (cut-off point of 60 mumol ZPP mol-1 haem). We can conclude that lead exposure in children in our sample was in the range reported in similar studies in other areas and countries, and below the toxic limit. None of the factors analysed significantly influenced lead intoxication prevalence. There was no good correlation between ZPP and BPb in our samples and the ZPP cut-off point used did not present good specificity and sensitivity values. PMID:9850561

  20. The relation between occupational exposure to lead and blood pressure among employed normotensive men

    PubMed Central

    Taheri, Ladan; Sadeghi, Masoumeh; Sanei, Hamid; Rabiei, Katayoun; Arabzadeh, Somayeh; Golshahi, Jafar; Afshar, Hamid; Sarrafzadegan, Nizal

    2014-01-01

    Background: Lead is a pollutant with numerous adverse effects on health. Since it can affect blood pressure, peripheral blood vessels, and the heart, the present study aimed to evaluate the relation between occupational exposure to lead and blood pressure. Materials and Methods: This cross-sectional study included male individuals working in battery firms in Isfahan. A questionnaire covering demographic characteristics and the history of different diseases and occupational exposure to lead was completed. Each participant's blood pressure was also measured and recorded. After obtaining blood samples and determining lead levels, mean and frequency analyses were performed. In addition, Pearson's correlation test and linear regression were used to assess the relation between blood lead levels (BLLs) and systolic and diastolic blood pressure. All analyses were performed in SPSS.19 Results: The mean age of the 182 studied workers was 42.85 ± 13.65 years. They had worked in battery firms for a mean period of 23.67 ± 14.72 years. Moreover, the mean value of BLLs among the participants was 7.92 ± 3.44 μg/dL. Correlation between BLL and systolic and diastolic blood pressure was not significant. The effects of lead on systolic and diastolic blood pressure after stepwise regression were B = –0.327 [confidence interval (CI) 95%: –0.877 to 0.223] and B = –0.094 (CI 95%: –0.495 to 0.307), respectively. Conclusion: This study revealed that BLLs in battery firm workers to be normal. Additionally, BLLs were not significantly related with either systolic or diastolic blood pressure which might have been the result of normal BLLs. PMID:25197288

  1. Maternal lead exposure during lactation persistently impairs testicular development and steroidogenesis in male offspring.

    PubMed

    Wang, Hua; Ji, Yan-Li; Wang, Qun; Zhao, Xian-Feng; Ning, Huan; Liu, Ping; Zhang, Cheng; Yu, Tao; Zhang, Ying; Meng, Xiu-Hong; Xu, De-Xiang

    2013-12-01

    Lead (Pb) is a testicular toxicant. In the present study, we investigated the effects of maternal Pb exposure during lactation on testicular development and steroidogenesis in male offspring. Maternal mice were exposed to different concentration of lead acetate (200 or 2000 ppm) through drinking water from postnatal day (PND) 0 to PND21. As expected, a high concentration of Pb was measured in the kidneys and liver of pups whose mothers were exposed to Pb during lactation. In addition, maternal Pb exposure during lactation elevated, to a less extent, Pb content in testes of weaning pups. Testis weight in weaning pups was significantly decreased when maternal mice were exposed to Pb during lactation. The level of serum and testicular T was reduced in Pb-exposed pups. The expression of P450scc, P450(17α) and 17β-HSD, key enzymes for T synthesis, was down-regulated in testes of weaning pups whose mothers were exposed to Pb during lactation. Interestingly, the level of serum and testicular T remained decreased in adult offspring whose mothers were exposed to Pb during lactation. Importantly, the number of spermatozoa was significantly reduced in Pb-exposed male offspring. Taken together, these results suggest that Pb could be transported from dams to pups through milk. Maternal Pb exposure during lactation persistently disrupts testicular development and steroidogenesis in male offspring. PMID:22806249

  2. Lead

    MedlinePlus

    ... Lead Share Facebook Twitter Google+ Pinterest Contact Us Lead Poisoning is Preventable If your home was built before ... of the RRP rule. Read more . Learn about Lead Poisoning Prevention Week . Report Uncertified Contractors and Environmental Violations ...

  3. Effects of sublethal exposure to lead on levels of energetic compounds in Procambarus clarkii (Girard, 1852)

    SciTech Connect

    Martinez, M.; Torreblanca, A.; Del Ramo, J.; Diaz-Mayans, J. )

    1994-05-01

    Lead is neither essential nor beneficial to living organisms; all existing data show that its metabolic effects are adverse. Lead is toxic to all phyla of aquatic biota. Most of the lead discharged into surface water is rapidly incorporated into suspended and bottom sediments. The American red crayfish, Procambarus clarkii, lives in a wide range of environmental conditions that include highly polluted waters. Lead present in take sediments can be available to aquatic animals such as P. clarkii because it is a detritivor and burrow into the sediment. In fact, we found remarkable levels of lead in tissues of P. clarkii caught in Albufera Lake and kept 15 days in clean water (e. g. 223 [mu]g/g dry weight in gills). Furthermore, P. clarkii has a high capacity for lead accumulation from water, and gills were the most important tissue of lead accumulation. Among effects that contaminants have on the physiology of the organisms, energetic state variables are important, since they will alter both survival and reproduction. Hepatopancreas is a major site for the energetic reserve in crayfish and is a site of lead accumulation, although metal concentration in this organ is not as high as gills. The purpose of this study was to examine changes in energy reserves in hepatopancreas and gills of the crayfish P. clarkii, in response to sublethal exposure to lead. Gills are directly exposed to contaminants in the environment, and they are the first organ showing alterations by the action of the contaminants. Hepatopancreas was also chosen due to both, its relevance in the energetic metabolism and its role in heavy metal detoxification mechanisms.

  4. Lead toxicity in a family as a result of occupational exposure.

    PubMed

    Raviraja, Aryapu; Babu, Gaja Narayanamurthy Vishal; Bijoor, Anita Raghuveer; Menezes, Geraldine; Venkatesh, Thuppil

    2008-06-01

    This article describes an entire family manufacturing lead acid batteries who all suffered from lead poisoning. The family of five lived in a house, part of which had been used for various stages of battery production for 14 years. Open space was used for drying batteries. They all drank water from a well located on the premises. Evaluation of biomarkers of lead exposure and/or effect revealed alarming blood lead levels [(3.92+/-0.94) micromol L-1], 50 % reduction in the activity of delta-aminolevulinic acid dehydratase [(24.67+/-5.12) U L-1] and an increase in zinc protoporphyrin [(1228+/-480) microg L-1]. Liver function tests showed an increase in serum alkaline phosphatase [(170.41+/-41.82) U L-1]. All other liver function test parameters were normal. Renal function tests showed an increase in serum uric acid [(515.81+/-86.29) micromol L-1] while urea and creatinine were normal. Serum calcium was low [(1.90+/-0.42) mmol L-1 in women and (2.09+/-0.12) mmol L-1 in men], while blood pressure was high in the head of the family and his wife and normal in children. Lead concentration in well water was estimated to 180 microg L-1. The family was referred to the National Referral Centre for Lead Poisoning in India, were they were received treatment and were informed about the hazards of lead poisoning. A follow up three months later showed a slight decrease in blood lead levels and a significant increase in haemoglobin. These findings can be attributed to behavioural changes adopted by the family, even though they continued producing lead batteries. PMID:18573750

  5. Evaluation of the potential role of chelation therapy in treatment of low to moderate lead exposures

    SciTech Connect

    Chisolm, J.J. Jr. )

    1990-11-01

    In the overall long-term management of lead poisoning, chelation therapy can have short-term benefits; however, these benefits must be accompanied by drastic reduction in environmental exposure to lead if therapy is to have any long-term benefit. This discussion is limited to calcium disodium ethylenediaminetetraacetate (CaNa{sub 2}EDTA), the chelating agent that has been the mainstay of treatment of lead poisoning for the past 38 years, and to meso-2,3-dimercaptosuccinic acid (DMSA), a new and promising oral chelating agent, which is an orphan drug and is currently classified as an investigational new drug by the US Food and Drug Administration. With both drugs, multiple courses of treatment will be needed if any substantial reduction in body lead burden is to be achieved. A major limitation of CaNa{sub 2}EDTA is the enormous diuresis of zinc that it produces. DMSA produces a comparable diuresis of lead, a greater decrease in blood lead, and has negligible influence on the urinary losses of zinc, copper, iron, and calcium. Limited experience to date in man has revealed no significant adverse side effects of DMSA. In animals, DMSA will promptly reduce the concentration of lead in brain and kidney, in particular. By contrast, similar 5-day courses of CaNa{sub 2}EDTA do not produce any net reduction in brain lead. This is important, as the brain is the critical organ of the adverse effects of lead in children. If the efficacy of DMSA is to be comprehensively evaluated ethically in children, new and more sensitive neurochemical, electrophysiologic, or other markers must be developed.

  6. Fetal death and reduced birth rates associated with exposure to lead-contaminated drinking water.

    PubMed

    Edwards, Marc

    2014-01-01

    This ecologic study notes that fetal death rates (FDR) during the Washington DC drinking water "lead crisis" (2000-2004) peaked in 2001 when water lead levels (WLLs) were highest, and were minimized in 2004 after public health interventions were implemented to protect pregnant women. Changes in the DC FDR vs neighboring Baltimore City were correlated to DC WLL (R(2) = 0.72). Birth rates in DC also increased versus Baltimore City and versus the United States in 2004-2006, when consumers were protected from high WLLs. The increased births in DC neighborhoods comparing 2004 versus 2001 was correlated to the incidence of lead pipes (R(2) = 0.60). DC birth rates from 1999 to 2007 correlated with proxies for maternal blood lead including the geometric mean blood lead in DC children (R(2) = 0.68) and the incidence of lead poisoning in children under age 1.3 years (R(2) = 0.64). After public health protections were removed in 2006, DC FDR spiked in 2007-2009 versus 2004-2006 (p < 0.05), in a manner consistent with high WLL health risks to consumers arising from partial lead service line replacements, and DC FDR dropped to historically low levels in 2010-2011 after consumers were protected and the PSLR program was terminated. Re-evaluation of a historic construction-related miscarriage cluster in the USA Today Building (1987-1988), demonstrates that high WLLs from disturbed plumbing were a possible cause. Overall results are consistent with prior research linking increased lead exposure to higher incidence of miscarriages and fetal death, even at blood lead elevations (≈5 μg/dL) once considered relatively low. PMID:24321041

  7. Environmental Exposure to Arsenic, Lead, and Cadmium in People Living near Janghang Copper Smelter in Korea.

    PubMed

    Kim, Yong-Dae; Eom, Sang-Yong; Yim, Dong-Hyuk; Kim, In-Soo; Won, Hee-Kwan; Park, Choong-Hee; Kim, Guen-Bae; Yu, Seung-Do; Choi, Byung-Sun; Park, Jung-Duck; Kim, Heon

    2016-04-01

    Concentrations of heavy metals exceed safety thresholds in the soil near Janghang Copper Refinery, a smelter in Korea that operated from 1936 to 1989. This study was conducted to evaluate the level of exposure to toxic metals and the potential effect on health in people living near the smelter. The study included 572 adults living within 4 km of the smelter and compared them with 413 controls group of people living similar lifestyles in a rural area approximately 15 km from the smelter. Urinary arsenic (As) level did not decrease according to the distance from the smelter, regardless of gender and working history in smelters and mines. However, in subjects who had no occupational exposure to toxic metals, blood lead (Pb) and cadmium (Cd) and urinary Cd decreased according to the distance from the smelter, both in men and women. Additionally, the distance from the smelter was a determinant factor for a decrease of As, Pb, and Cd in multiple regression models, respectively. On the other hands, urinary Cd was a risk factor for renal tubular dysfunction in populations living near the smelter. These results suggest that Janghang copper smelter was a main contamination source of As, Pb, and Cd, and populations living near the smelter suffered some adverse health effects as a consequence. The local population should be advised to make efforts to reduce exposure to environmental contaminants, in order to minimize potential health effects, and to pay close attention to any health problems possibly related to toxic metal exposure. PMID:27051230

  8. Environmental Exposure to Arsenic, Lead, and Cadmium in People Living near Janghang Copper Smelter in Korea

    PubMed Central

    2016-01-01

    Concentrations of heavy metals exceed safety thresholds in the soil near Janghang Copper Refinery, a smelter in Korea that operated from 1936 to 1989. This study was conducted to evaluate the level of exposure to toxic metals and the potential effect on health in people living near the smelter. The study included 572 adults living within 4 km of the smelter and compared them with 413 controls group of people living similar lifestyles in a rural area approximately 15 km from the smelter. Urinary arsenic (As) level did not decrease according to the distance from the smelter, regardless of gender and working history in smelters and mines. However, in subjects who had no occupational exposure to toxic metals, blood lead (Pb) and cadmium (Cd) and urinary Cd decreased according to the distance from the smelter, both in men and women. Additionally, the distance from the smelter was a determinant factor for a decrease of As, Pb, and Cd in multiple regression models, respectively. On the other hands, urinary Cd was a risk factor for renal tubular dysfunction in populations living near the smelter. These results suggest that Janghang copper smelter was a main contamination source of As, Pb, and Cd, and populations living near the smelter suffered some adverse health effects as a consequence. The local population should be advised to make efforts to reduce exposure to environmental contaminants, in order to minimize potential health effects, and to pay close attention to any health problems possibly related to toxic metal exposure. PMID:27051230

  9. Reduction of radiation exposure by lead curtain shielding in dedicated extremity cone beam CT

    PubMed Central

    Lee, C-H; Ryu, J H; Lee, Y-H

    2015-01-01

    Objective: A dedicated extremity cone beam CT (CBCT) was introduced recently, and is rapidly becoming an attractive modality for extremity imaging. This study aimed to evaluate the effectiveness of a curtain-shaped lead shielding in reducing the exposure of patients to scattered radiation in dedicated extremity CBCT. Methods: A dedicated extremity CBCT scanner was used. The lead shielding curtain was 42 × 60 cm with 0.5-mm lead equivalent. Scattered radiation dose from CBCT was measured using thermoluminescence dosimetry chips at 20 points, at different distances and directions from the CT gantry. Two sets of scattered radiation dose measurements were performed before and after installation of curtain-shaped lead shield, and the percentage reduction in dose in air was calculated. Results: Mean radiation exposure dose at measured points was 34.46 ± 48.40 μGy without curtains and 9.67 ± 4.53 μGy with curtains, exhibiting 71.94% reduction (p = 0.000). The use of lead shielding curtains significantly reduced scattered radiation at 0.5, 1.0 and 1.5 m from the CT gantry, with percent reductions of 84.8%, 58.0% and 35.5%, respectively (p = 0.000, 0.000 and 0.002). The percent reduction in the diagonal (+45°, −45°) and vertical forward (0°) directions were 86.3%, 83.1% and 77.7%, respectively, and were statistically significant (p = 0.029, 0.020 and 0.041). Conclusion: Shielding with lead curtains suggests an easy and effective method for reducing patient exposure to radiation in extremity CBCT imaging. Advances in knowledge: Lead shielding curtains are an effective technique to reduce scattered radiation dose in dedicated extremity CBCT, with higher dose reduction closer to the gantry opening. PMID:25811096

  10. Prevalence of lead exposure among age and sex cohorts of Canada geese

    USGS Publications Warehouse

    DeStefano, S.; Brand, C.J.; Rusch, D.H.

    1992-01-01

    We examined the prevalence of lead exposure from ingestion of waste lead shot among age and sex cohorts of Canada geese (Branta canadensis) on the breeding, migration, and wintering grounds of the Eastern Prairie Population. Blood samples from 6963 geese were assayed for lead concentration by atomic absorption spectrophotometry. On the breeding grounds, no goslings and < 1 % of adults showed evidence of recent exposure to lead shot (i.e., concentrations in the blood elevated above the threshold value of 0. 18 ppm lead). However, median background blood lead concentrations (i.e., blood samples with < 0.18 ppm lead) were higher in adults than goslings, indicating that exposure of adults to lead had occurred during previous seasons. Waste lead shot was available on the migration and wintering grounds, where a larger proportion of the blood samples from immatures (< 1 year old) than adults (> 1 year old) had lead concentrations greater-than-or-equal-to 0.18 ppm. Median background lead levels remained higher in adults than in immatures throughout fall and winter. We also found that more immature males than immature females had elevated lead concentrations. Higher rates of intake of food and grit (including shot) probably partially account for the higher prevalence of elevated lead concentrations in immature Canada geese.//Nous avons ??tudi?? l'importance des expositions au plomb par ingestion de plombs de chasse chez les diff??rentes cohortes (??ge et sexe) de Bernaches du Canada (Branta canadensis) dans les zones de reproduction et de migration et dans les territoires d'hiver chez la population de la Prairie de l'Est. Des ??chantillons de sang ont ??t?? pr??lev??s chez 6963 bernaches et analys??s au sphectrophotom??tre ? absorption atomique pour en d??terminer le contenu en plomb. Dans les zones de reproduction, les traces d'exposition r??cente ? des plombs (i.e. concentrations de plomb dans le sang au-dessus de la valeur seuil de 0,18 ppm) ??taient apparentes chez

  11. Lead exposures and biological responses in military weapons systems: Aerosol characteristics and acute lead effects among US Army artillerymen: Final report

    SciTech Connect

    Bhattacharyya, M.H.; Stebbings, J.H.; Peterson, D.P.; Johnson, S.A.; Kumar, R.; Goun, B.D.; Janssen, I.; Trier, J.E.

    1993-03-01

    This study was to determine the concentration and chemical nature of lead (Pb) aerosols produced during the firing of artillery and to determine the exposures and biological responses of crew members exposed to lead aerosols during such firing. The concentrations of lead-containing aerosols at crew positions depended on wind conditions, with higher concentrations when firing into a head wind. Aerosol concentrations were highest in the muzzle blast zone. Concentrations of lead in the blood of crew members rose during the first 12 days of exposure to elevated airborne lead concentrations and then leveled off. There was no rapid decrease in blood lead concentrations after completion of firing. Small decreases in hematocrit and small increases in free erythrocyte porphyrin were correlated with increasing exposure to airborne lead. These changes were reversed by seven weeks after firing. Changes in nerve conduction velocity had borderline statistical significance to airborne lead exposure. In measuring nerve conduction velocity, differences in skin temperature must be taken into account.

  12. Calibrating a population-based job-exposure matrix using inspection measurements to estimate historical occupational exposure to lead for a population-based cohort in Shanghai, China.

    PubMed

    Koh, Dong-Hee; Bhatti, Parveen; Coble, Joseph B; Stewart, Patricia A; Lu, Wei; Shu, Xiao-Ou; Ji, Bu-Tian; Xue, Shouzheng; Locke, Sarah J; Portengen, Lutzen; Yang, Gong; Chow, Wong-Ho; Gao, Yu-Tang; Rothman, Nathaniel; Vermeulen, Roel; Friesen, Melissa C

    2014-01-01

    The epidemiologic evidence for the carcinogenicity of lead is inconsistent and requires improved exposure assessment to estimate risk. We evaluated historical occupational lead exposure for a population-based cohort of women (n=74,942) by calibrating a job-exposure matrix (JEM) with lead fume (n=20,084) and lead dust (n=5383) measurements collected over four decades in Shanghai, China. Using mixed-effect models, we calibrated intensity JEM ratings to the measurements using fixed-effects terms for year and JEM rating. We developed job/industry-specific estimates from the random-effects terms for job and industry. The model estimates were applied to subjects' jobs when the JEM probability rating was high for either job or industry; remaining jobs were considered unexposed. The models predicted that exposure increased monotonically with JEM intensity rating and decreased 20-50-fold over time. The cumulative calibrated JEM estimates and job/industry-specific estimates were highly correlated (Pearson correlation=0.79-0.84). Overall, 5% of the person-years and 8% of the women were exposed to lead fume; 2% of the person-years and 4% of the women were exposed to lead dust. The most common lead-exposed jobs were manufacturing electronic equipment. These historical lead estimates should enhance our ability to detect associations between lead exposure and cancer risk in the future epidemiologic analyses. PMID:22910004

  13. Calibrating a population-based job-exposure matrix using inspection measurements to estimate historical occupational exposure to lead for a population-based cohort in Shanghai, China

    PubMed Central

    Koh, Dong-Hee; Bhatti, Parveen; Coble, Joseph B.; Stewart, Patricia A; Lu, Wei; Shu, Xiao-Ou; Ji, Bu-Tian; Xue, Shouzheng; Locke, Sarah J.; Portengen, Lutzen; Yang, Gong; Chow, Wong-Ho; Gao, Yu-Tang; Rothman, Nathaniel; Vermeulen, Roel; Friesen, Melissa C.

    2012-01-01

    The epidemiologic evidence for the carcinogenicity of lead is inconsistent and requires improved exposure assessment to estimate risk. We evaluated historical occupational lead exposure for a population-based cohort of women (n=74,942) by calibrating a job-exposure matrix (JEM) with lead fume (n=20,084) and lead dust (n=5,383) measurements collected over four decades in Shanghai, China. Using mixed-effect models, we calibrated intensity JEM ratings to the measurements using fixed-effects terms for year and JEM rating. We developed job/industry-specific estimates from the random-effects terms for job and industry. The model estimates were applied to subjects’ jobs when the JEM probability rating was high for either job or industry; remaining jobs were considered unexposed. The models predicted that exposure increased monotonically with JEM intensity rating and decreased 20–50-fold over time. The cumulative calibrated JEM estimates and job/industry-specific estimates were highly correlated (Pearson correlation=0.79–0.84). Overall, 5% of the person-years and 8% of the women were exposed to lead fume; 2% of the person-years and 4% of the women were exposed to lead dust. The most common lead-exposed jobs were manufacturing electronic equipment. These historical lead estimates should enhance our ability to detect associations between lead exposure and cancer risk in future epidemiologic analyses. PMID:22910004

  14. Occupational and environmental lead and PCB exposure at a scrap metal dealer

    SciTech Connect

    Malkin, R.

    1995-07-01

    Blood lead levels (BPb) and serum polychlorinated biphenyl levels (PCB) were obtained from 17 employees at two adjacent scrap metal dealers. One facility was located outdoors, directly on top of soil known to be contaminated with lead and PCBs, and the other was located indoors with a concrete floor. BPbs ranged from 4.0 to 39.8 {mu}g/dl (mean 19.9 {mu}g/dl, geometric mean 17.5 {mu}g/dl) and PCB levels ranged from <1 to 65.3 ppb (mean 7.5 ppb). There was no significant difference in either BPb or serum PCB between the two sites. BPb was significantly correlated with the number of cigarettes smoked at work, and both BPb and serum PCB were significantly related to eating lunch outside the lunchroom, suggesting hand-to-mouth contact as a source of exposure. The lack of difference in BPb between employees of the two scrap metal dealers suggests an ongoing source of lead exposure at the sites, other than the soil. 10 refs., 2 tabs.

  15. Effect of in vitro exposure to lead chloride on semen quality and sperm DNA fragmentation.

    PubMed

    Gomes, M; Gonçalves, A; Rocha, E; Sá, R; Alves, A; Silva, J; Barros, A; Pereira, M L; Sousa, M

    2015-06-01

    Exposure to lead may cause changes in the male reproductive system. We evaluated the effect of lead chloride (PbCl2) in vitro on semen quality from 31 individuals. Samples were incubated at room temperature for two exposure times (4 h and 8 h) and with two concentrations of PbCl2 (15 μg/ml or 30 μg/ml). Results showed that PbCl2 significantly inhibited rapid progressive motility and caused an increase in the percentage of tail anomalies in both times and concentrations assessed, as well as a decrease in vitality in the group exposed to 30 μg/ml PbCl2. A significant increase in immotile sperm was also observed between the group control and the groups submitted to lead. Total motility and DNA fragmentation also showed a significant decrease and increase, respectively, after 4 h of incubation in the group exposed to 30 μg/ml and in both groups after 8 h of incubation. In conclusion, PbCl2 affected sperm parameters and DNA integrity, which are essential for male fertility. PMID:24521979

  16. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration.

    PubMed

    Clunes, Lucy A; Davies, Catrin M; Coakley, Raymond D; Aleksandrov, Andrei A; Henderson, Ashley G; Zeman, Kirby L; Worthington, Erin N; Gentzsch, Martina; Kreda, Silvia M; Cholon, Deborah; Bennett, William D; Riordan, John R; Boucher, Richard C; Tarran, Robert

    2012-02-01

    Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB. PMID:21990373

  17. Effect of environmental exposures to lead and cadmium on human lymphocytic detoxifying enzymes

    SciTech Connect

    D'Souza, S.J.; Narurkar, L.M.; Narurkar, M.V. )

    1994-09-01

    Lead (Pb) is among the most toxic heavy elements in the atmosphere. Aerosol lead enters the human blood stream by way of the respiratory tract and indirectly, by surface disposition in the alimentary tract followed by adsorption. Lead pollution is also known to occur through its presence in petrol, pain, glazed vessels and solder. Atmospheric lead pollution may be predominantly high around factories manufacturing Pb alloys. Lead toxicity is associated with inhibition of [alpha]-aminolevulinic acid dehydrase (ALAD) activity, rise in the blood porphyrin, inhibition of ATPase in erthrocytes, decreased blood haemoglobin and anemia. Elevated lead concentrations in pregnant women have been shown to cause hypertension and birth defects. Lead is also known to interact with other elements such as Fe, Zn, Ca and Cu in biological systems. Cadmium (Cd) is not essential for human body. It enters the human environment as a contaminant. Human intake of Cd is chiefly through the food chain (about 400-500 [mu]g/wk). Analysis of neuropsy material shows that smokers accumulate much more Cd than nonsmokers. Chronic Cd poisoning produces proteinuere and affects the proximal tubules of kidney, causing the formation of kidney stones. The reported hypertensive effect of Cd in man has been associated with high Cd/Zn ratio in kidney. Studies on air pollution have shown that Cd concentration in air could be positively correlated with heart disease, hypertension and arteriosclerosis. The present investigation was aimed at assessing the usefulness of human lymphocytic detoxicating enzyme activities and their ratios in an assessment of human health-risks during environmental exposures to Pb and Cd. The human subjects investigated comprised those exposed to highly contaminated lead and cadmium areas in the state of Maharashtra, India. 17 refs., 2 figs.

  18. Electrophysiologic and behavioral effects of perinatal and acute exposure of rats to lead and polychlorinated biphenyls.

    PubMed Central

    Carpenter, David O; Hussain, Rifat J; Berger, David F; Lombardo, John P; Park, Hye-Youn

    2002-01-01

    Lead and polychlorinated biphenyls (PCBs) both cause a reduction of intelligence quotient and behavioral abnormalities in exposed children that have features in common with attention deficit hyperactivity disorder. We have used rats as a model to study the effects of both perinatal and acute exposure to lead or PCBs in an effort to compare and understand the mechanisms of these nervous system decrements. Long-term potentiation (LTP) is an electrophysiologic measurement that correlates well with cognitive ability. We have determined the effects of chronic perinatal exposure to lead or PCB 153 as well as acute application of these substances to isolated brain slices, with recordings in two areas of the hippocampus, CA1 and CA3. Both substances, whether chronically or acutely applied, significantly reduced LTP in CA1 in animals at age 30 and 60 days. In CA3, they reduced LTP in 30-day animals but potentiated it in 60-day animals. Although neither lead nor PCB 153 alters baseline synaptic transmission at low stimulus strengths, at higher levels they induce changes in the same direction as those of LTP. These results show surprisingly similar actions of these quite different chemicals, and the similarity of effects on chronic and acute application indicates that effects are both pharmacologic and developmental. Behavioral studies of rats exposed to PCBs from contaminated fish show hyperactivity, impulsiveness, and increased frustration relative to unexposed controls. These results demonstrate that lead and PCBs have similar effects on synaptic plasticity and behavior and suggest that the compounds may act through a common mechanism. PMID:12060832

  19. Lead

    MedlinePlus

    ... obvious symptoms, it frequently goes unrecognized. CDC’s Childhood Lead Poisoning Prevention Program is committed to the Healthy People ... Lead Levels Information for Parents Tips for preventing lead poisoning About Us Overview of CDC’s Childhood Lead Poisoning ...

  20. Blood lead exposure concentrations in mottled ducks (Anas fulvigula) on the upper Texas coast

    USGS Publications Warehouse

    McDowell, Stephen K.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.; Hung, I-Kuai

    2015-01-01

    The mottled duck (Anas fulvigula) is a non-migratory waterfowl species dependent upon coastal marsh systems, including those on the Texas Chenier Plain National Wildlife Refuge (NWR) Complex, and considered a regional indicator species of marsh habitat quality. Research from the early 1970s, 1990s, and early-2000s indicated that mottled ducks continued to exhibit elevated wing-bone lead (Pb) concentrations, decades after implementation of non-toxic shot regulations. However, wing-bone concentrations reflect lifetime accumulation of Pb, whereas blood Pb concentrations reflect more recent exposure. To identify current potentially relevant temporal windows of Pb exposure, we collected 260 blood samples from mottled ducks during summer (n=124) and winter (n=136) from 2010–2012 on the Texas Chenier Plain NWR Complex. We quantified baseline blood Pb concentrations for all ages of mottled ducks, and hypothesized that blood lead concentrations would remain elevated above background levels (200 µg L–1) despite the 1983 and 1991 lead shot bans. Blood Pb concentrations ranged from below detection limits to >12,000 µg L–1, where >200 µg L–1 was associated with exposure levels above background concentrations. Male mottled ducks had the greatest blood Pb concentrations (30 times greater than females) with concentrations greater during winter than summer. Likewise, the proportion of exposed (>200 µg L–1) females increased from 14%–47% from summer to winter, respectively. Regardless of sex, adult mottled duck blood Pb concentrations were five times greater than juveniles, particularly during winter. We identified five plausible models that influenced blood Pb levels where year, site, and interactions among age*sex*season and between age*season were included in the top-ranked models. Frequency of exposure was greatest during winter, increasing from 12% in summer to 55% in winter, indicating that a temporal exposure window to environmental Pb exists between nesting

  1. Developmental alcohol exposure leads to a persistent change on astrocyte secretome.

    PubMed

    Trindade, Pablo; Hampton, Brian; Manhães, Alex C; Medina, Alexandre E

    2016-06-01

    Fetal alcohol spectrum disorder is the most common cause of mental disabilities in the western world. It has been quite established that acute alcohol exposure can dramatically affect astrocyte function. Because the effects of early alcohol exposure on cell physiology can persist into adulthood, we tested the hypothesis that ethanol exposure in ferrets during a period equivalent to the last months of human gestation leads to persistent changes in astrocyte secretome in vitro. Animals were treated with ethanol (3.5 g/kg) or saline between postnatal day (P)10-30. At P31, astrocyte cultures were made and cells were submitted to stable isotope labeling by amino acids. Twenty-four hour conditioned media of cells obtained from ethanol- or saline-treated animals (ET-CM or SAL-CM) were collected and analyzed by quantitative mass spectrometry in tandem with liquid chromatography. Here, we show that 65 out of 280 quantifiable proteins displayed significant differences comparing ET-CM to SAL-CM. Among the 59 proteins that were found to be reduced in ET-CM we observed components of the extracellular matrix such as laminin subunits α2, α4, β1, β2, and γ1 and the proteoglycans biglycan, heparan sulfate proteoglycan 2, and lumican. Proteins with trophic function such as insulin-like growth factor binding protein 4, pigment epithelium-derived factor, and clusterin as well as proteins involved on modulation of proteolysis such as metalloproteinase inhibitor 1 and plasminogen activator inhibitor-1 were also reduced. In contrast, pro-synaptogeneic proteins like thrombospondin-1, hevin as well as the modulator of extracelular matrix expression, angiotensinogen, were found increased in ET-CM. The analysis of interactome maps through ingenuity pathway analysis demonstrated that the amyloid beta A4 protein precursor, which was found reduced in ET-CM, was previously shown to interact with ten other proteins that exhibited significant changes in the ET-CM. Taken together our results

  2. Exposure Evaluation for Benzene, Lead and Noise in Vehicle and Equipment Repair Shops

    SciTech Connect

    Sweeney, Lynn C.

    2013-04-01

    An exposure assessment was performed at the equipment and vehicle maintenance repair shops operating at the U. S. Department of Energy Hanford site, in Richland, Washington. The maintenance shops repair and maintain vehicles and equipment used in support of the Hanford cleanup mission. There are three general mechanic shops and one auto body repair shop. The mechanics work on heavy equipment used in construction, cranes, commercial motor vehicles, passenger-type vehicles in addition to air compressors, generators, and farm equipment. Services include part fabrication, installation of equipment, repair and maintenance work in the engine compartment, and tire and brake services. Work performed at the auto body shop includes painting and surface preparation which involves applying body filler and sanding. 8-hour time-weighted-average samples were collected for benzene and noise exposure and task-based samples were collected for lead dust work activities involving painted metal surfaces. Benzene samples were obtained using 3M™ 3520 sampling badges and were analyzed for additional volatile organic compounds. These compounds were selected based on material safety data sheet information for the aerosol products used by the mechanics for each day of sampling. The compounds included acetone, ethyl ether, toluene, xylene, VM&P naphtha, methyl ethyl ketone, and trichloroethylene. Laboratory data for benzene, VM&P naphtha, methyl ethyl ketone and trichloroethylene were all below the reporting detection limit. Airborne concentrations for acetone, ethyl ether, toluene and xylene were all less than 10% of their occupational exposure limit. The task-based samples obtained for lead dusts were submitted for a metal scan analysis to identify other metals that might be present. Laboratory results for lead dusts were all below the reporting detection limit and airborne concentration for the other metals observed in the samples were less than 10% of the occupational exposure limit

  3. Cadmium, mercury, and lead in kidney cortex of living kidney donors: Impact of different exposure sources,

    SciTech Connect

    Barregard, Lars; Fabricius-Lagging, Elisabeth; Lundh, Thomas; Moelne, Johan; Wallin, Maria; Olausson, Michael; Modigh, Cecilia; Sallsten, Gerd

    2010-01-15

    Background: Most current knowledge on kidney concentrations of nephrotoxic metals like cadmium (Cd), mercury (Hg), or lead (Pb) comes from autopsy studies. Assessment of metal concentrations in kidney biopsies from living subjects can be combined with information about exposure sources like smoking, diet, and occupation supplied by the biopsied subjects themselves. Objectives: To determine kidney concentrations of Cd, Hg, and Pb in living kidney donors, and assess associations with common exposure sources and background factors. Methods: Metal concentrations were determined in 109 living kidney donors aged 24-70 years (median 51), using inductively coupled plasma-mass spectrometry (Cd and Pb) and cold vapor atomic fluorescence spectrometry (Hg). Smoking habits, occupation, dental amalgam, fish consumption, and iron stores were evaluated. Results: The median kidney concentrations were 12.9 {mu}g/g (wet weight) for cadmium, 0.21 {mu}g/g for mercury, and 0.08 {mu}g/g for lead. Kidney Cd increased by 3.9 {mu}g/g for a 10 year increase in age, and by 3.7 {mu}g/g for an extra 10 pack-years of smoking. Levels in non-smokers were similar to those found in the 1970s. Low iron stores (low serum ferritin) in women increased kidney Cd by 4.5 {mu}g/g. Kidney Hg increased by 6% for every additional amalgam surface, but was not associated with fish consumption. Lead was unaffected by the background factors surveyed. Conclusions: In Sweden, kidney Cd levels have decreased due to less smoking, while the impact of diet seems unchanged. Dental amalgam is the main determinant of kidney Hg. Kidney Pb levels are very low due to decreased exposure.

  4. Sources of potential lead exposure among pregnant women in New Mexico.

    PubMed

    Bakhireva, Ludmila N; Rowland, Andrew S; Young, Bonnie N; Cano, Sandra; Phelan, Sharon T; Artyushkova, Kateryna; Rayburn, William F; Lewis, Johnnye

    2013-01-01

    The objectives of this study were to ascertain the prevalence and potential sources of lead exposure among pregnant women residing in a socially-disadvantaged immigrant community in Albuquerque, New Mexico. Pregnant women (n = 140) receiving prenatal care through a community clinic participated in a structured interview and screening to measure their blood lead levels (BLLs). Potential sources of lead exposure were ascertained by the CDC and New Mexico Department of Health questionnaires. Self-reported risk factors were examined as predictors of BLLs using multiple linear regression and partial least squares discriminant analysis. Most patients were Spanish-speaking (88.6%), Latina (95%), foreign-born (87.1%), lacked health insurance (86.4%), and had a high school education or lower (84.3%). While risk factors were prevalent in this population, only three women (2.1%) had BLLs ≥3 μg/dL. Results of multivariate analyses demonstrated that pica symptoms in pregnancy, history of elevated BLLs before pregnancy, use of non-commercial pottery, and living in older houses were important predictors of elevated BLLs. Although the prevalence of other risk factors relevant to immigrant communities (i.e., use of traditional/folk remedies and cosmetics, seasonings and food products from Mexico) was high, they were not predictive of elevated BLLs. Clinics providing prenatal care to immigrant Hispanic communities should carefully assess patients' pica symptoms, use of non-commercial pottery, and a history of elevated BLLs. Moreover, additional efforts need to focus on the development of screening questionnaires which better reflect exposures of concern in this population. PMID:22362260

  5. Foliar or root exposures to smelter particles: consequences for lead compartmentalization and speciation in plant leaves.

    PubMed

    Schreck, Eva; Dappe, Vincent; Sarret, Géraldine; Sobanska, Sophie; Nowak, Dorota; Nowak, Jakub; Stefaniak, Elżbieta Anna; Magnin, Valérie; Ranieri, Vincent; Dumat, Camille

    2014-04-01

    In urban areas with high fallout of airborne particles, metal uptake by plants mainly occurs by foliar pathways and can strongly impact crop quality. However, there is a lack of knowledge on metal localization and speciation in plants after pollution exposure, especially in the case of foliar uptake. In this study, two contrasting crops, lettuce (Lactuca sativa L.) and rye-grass (Lolium perenne L.), were exposed to Pb-rich particles emitted by a Pb-recycling factory via either atmospheric or soil application. Pb accumulation in plant leaves was observed for both ways of exposure. The mechanisms involved in Pb uptake were investigated using a combination of microscopic and spectroscopic techniques (electron microscopy, laser ablation, Raman microspectroscopy, and X-ray absorption spectroscopy). The results show that Pb localization and speciation are strongly influenced by the type of exposure (root or shoot pathway) and the plant species. Foliar exposure is the main pathway of uptake, involving the highest concentrations in plant tissues. Under atmospheric fallouts, Pb-rich particles were strongly adsorbed on the leaf surface of both plant species. In lettuce, stomata contained Pb-rich particles in their apertures, with some deformations of guard cells. In addition to PbO and PbSO4, chemical forms that were also observed in pristine particles, new species were identified: organic compounds (minimum 20%) and hexagonal platy crystals of PbCO3. In rye-grass, the changes in Pb speciation were even more egregious: Pb-cell wall and Pb-organic acid complexes were the major species observed. For root exposure, identified here as a minor pathway of Pb transfer compared to foliar uptake, another secondary species, pyromorphite, was identified in rye-grass leaves. Finally, combining bulk and spatially resolved spectroscopic techniques permitted both the overall speciation and the minor but possibly highly reactive lead species to be determined in order to better assess the

  6. Effect of subacute exposure to lead and estrogen on immature pre-weaning rat leukocytes

    SciTech Connect

    Villagra, R.; Tchernitchin, N.N.; Tchernitchin, A.N.

    1997-02-01

    Lead is an environmental pollutant known to cause damage to human health, affecting specially the central nervous system, reproductive organs, the immune system and kidney. From the perspective or reproduction, lead affects both men and women. Reported effects in women include infertility, miscarriage, pre-eclampsia, pregnancy hypertension and premature delivery. In experimental animals, lead affects female reproductive organs through different mechanisms. The heavy metal may interact at the enzyme level. It may interfere with the action of reproductive hormones at the target organ, modifying the activity of estrogen receptors in the pregnant uterus and inhibiting responses where estrogens play a role. Lead may induce imprinting mechanism, causing persistent changes in uterine estrogen receptors and ovary LH receptors following perinatal exposure. Finally, it may interfere at the level of hypothalamus-pituitary, decreasing pituitary response to growth hormone releasing factor, affecting levels of FSH and LH and increasing blood levels of glucocorticoids, which modify the action of estrogens in the uterus. This study examines the mechanisms of lead-induced interference with female reproductive and immune functions. 33 refs., 2 figs., 2 tabs.

  7. Early postnatal lead exposure: behavioral effects in common tern chicks (Sterna Hirundo)

    SciTech Connect

    Burger, J.; Gochfeld, M.

    1985-01-01

    Exposure to lead early in life is known to affect behavioral and intellectual development. To develop an animal model the authors chose the common tern, Sterna hirundo, a species whose early developmental landmarks are well known. One potential for avian models lies in the reliance of birds on visual and acoustic rather than olfactory (and ultrasonic) modes of communication. One randomly chosen member from each of 8 pairs of young common tern chicks was injected with lead nitrate solution at a concentration of 0.2 mg/g. The pairs were not siblings but were matched for age (+/-1 d) and weight (+/-3 g). The second member of each pair was injected with an equal volume of sterile saline. Behavioral tests performed examined locomotion, balance and righting response, feeding tasks and begging, depth perception and response on a visual cliff, and behavioral thermoregulation. In each pair the control chick was heavier at 4 wk of age. For most behavioral measures, except begging and movement on a stationary incline, the lead-injected chicks performed less well than the control chicks. When presented with a novel feeding situation (reversal of fish position), the lead-injected chicks required significantly more time to eat the same number of fish. The single injection of lead, thus, affected a variety of behavioral patterns, with effects apparent within 5 d after injection.

  8. Surface exposure to sunlight stimulates CO2 release from permafrost soil carbon in the Arctic

    PubMed Central

    Cory, Rose M.; Crump, Byron C.; Dobkowski, Jason A.; Kling, George W.

    2013-01-01

    Recent climate change has increased arctic soil temperatures and thawed large areas of permafrost, allowing for microbial respiration of previously frozen C. Furthermore, soil destabilization from melting ice has caused an increase in thermokarst failures that expose buried C and release dissolved organic C (DOC) to surface waters. Once exposed, the fate of this C is unknown but will depend on its reactivity to sunlight and microbial attack, and the light available at the surface. In this study we manipulated water released from areas of thermokarst activity to show that newly exposed DOC is >40% more susceptible to microbial conversion to CO2 when exposed to UV light than when kept dark. When integrated over the water column of receiving rivers, this susceptibility translates to the light-stimulated bacterial activity being on average from 11% to 40% of the total areal activity in turbid versus DOC-colored rivers, respectively. The range of DOC lability to microbes seems to depend on prior light exposure, implying that sunlight may act as an amplification factor in the conversion of frozen C stores to C gases in the atmosphere. PMID:23401500

  9. Investigation of Childhood Lead Poisoning from Parental Take-Home Exposure from an Electronic Scrap Recycling Facility — Ohio, 2012.

    PubMed

    Newman, Nick; Jones, Camille; Page, Elena; Ceballos, Diana; Oza, Aalok

    2015-07-17

    Lead affects the developing nervous system of children, and no safe blood lead level (BLL) in children has been identified. Elevated BLLs in childhood are associated with hyperactivity, attention problems, conduct problems, and impairment in cognition. Young children are at higher risk for environmental lead exposure from putting their hands or contaminated objects in their mouth. Although deteriorating lead paint in pre-1979 housing is the most common source of lead exposure in children, data indicate that ≥30% of children with elevated BLLs were exposed through a source other than paint. Take-home contamination occurs when lead dust is transferred from the workplace on employees' skin, clothing, shoes, and other personal items to their car and home. Recycling of used electronics (e-scrap) is a relatively recent source of exposure to developmental neurotoxicants, including lead. In 2010, the Cincinnati Health Department and Cincinnati Children's Hospital Pediatric Environmental Health Specialty Unit (PEHSU) investigated two cases of childhood lead poisoning in a single family. In 2012, CDC's National Institute for Occupational Safety and Health (NIOSH) learned about the lead poisonings during an evaluation of the e-scrap recycling facility where the father of the two children with lead poisoning worked. This report summarizes the case investigation. Pediatricians should ask about parents' occupations and hobbies that might involve lead when evaluating elevated BLLs in children, in routine lead screening questionnaires, and in evaluating children with signs or symptoms of lead exposure. PMID:26182192

  10. Potential health risks to adults and children in the UK from exposure to dietary lead in gamebirds shot with lead ammunition.

    PubMed

    Green, R E; Pain, D J

    2012-11-01

    We estimate potential risks to human health in the UK from dietary exposure to lead from wild gamebirds killed by shooting. The main source of exposure to lead in Europe is now dietary. We used data on lead concentrations in UK gamebirds, from which gunshot had been removed following cooking to simulate human exposure to lead. We used UK food consumption and lead concentration data to evaluate the number of gamebird meals consumed weekly that would be expected, based upon published studies, to result in changes, over and above those resulting from exposure to lead in the base diet, in intelligence quotient (IQ), Systolic Blood Pressure and chronic kidney disease (CKD) considered in a recent opinion of the European Food Safety Authority (EFSA) to be significant at a population level and also in SAT test scores and in rates of spontaneous abortion. We found the consumption of <1 meal of game a week may be associated with a one point reduction in IQ in children and 1.2-6.5 gamebird meals per week may be associated with the other effects. These results should help to inform the development of appropriate responses to the risks from ingesting lead from ammunition in game in the UK and European Union (EU). PMID:22939931

  11. Lead exposure through consumption of big game meat in Quebec, Canada: risk assessment and perception.

    PubMed

    Fachehoun, Richard Coovi; Lévesque, Benoit; Dumas, Pierre; St-Louis, Antoine; Dubé, Marjolaine; Ayotte, Pierre

    2015-01-01

    Game meat from animals killed by lead ammunition may expose consumers to lead. We assessed the risk related to lead intake from meat consumption of white-tailed deer and moose killed by lead ammunition and documented the perception of hunters and butchers regarding this potential contamination. Information on cervid meat consumption and risk perception were collected using a mailed self-administrated questionnaire which was addressed to a random sample of Quebec hunters. In parallel, 72 samples of white-tailed deer (n = 35) and moose (n = 37) meats were collected from voluntary hunters and analysed for lead content using inductively coupled plasma-mass spectrometry. A risk assessment for people consuming lead shot game meat was performed using Monte Carlo simulations. Mean lead levels in white-tailed deer and moose killed by lead ammunition were 0.28 and 0.17 mg kg(-1) respectively. Risk assessment based on declared cervid meat consumption revealed that 1.7% of the surveyed hunters would exceed the dose associated with a 1 mmHg increase in systolic blood pressure (SBP). For consumers of moose meat once, twice or three times a week, simulations predicted that 0.5%, 0.9% and 1.5% of adults would be exposed to a dose associated with a 1 mmHg increase in SBP, whereas 0.9%, 1.9% and 3.3% of children would be exposed to a dose associated with 1 point intelligence quotient (IQ) decrease, respectively. For consumers of deer meat once, twice or three times a week, the proportions were 1.6%, 2.9% and 4% for adults and 2.9%, 5.8% and 7.7% for children, respectively. The consumption of meat from cervids killed with lead ammunition may increase lead exposure and its associated health risks. It would be important to inform the population, particularly hunters, about this potential risk and promote the use of lead-free ammunition. PMID:26161681

  12. The integrated exposure uptake biokinetic model for lead in children: independent validation and verification.

    PubMed Central

    Zaragoza, L; Hogan, K

    1998-01-01

    The U.S. Environmental Protection Agency employs a model, the integrated exposure biokinetic (IEUBK) model for lead in children, for the assessment of risks to children posed by environmental lead at hazardous waste sites. This paper describes results of an effort to verify the consistency of the documentation with the computer model and to test the computer code using a group that is independent from those involved in the model development. This review concluded that the IEUBK model correctly calculates the equations specified in the IEUBK model theory documentation. However, several issues were identified on model documentation, model performance, and the C++ programming language code (i.e., IEUBK model source code) documentation. These issues affect the ability of an independent reviewer to understand the workings of the IEUBK model but not the model's reliability. As a result of these findings, recommendations have been provided for updating documentation to the model as well as associated adjustments to the model documentation. PMID:9860914

  13. NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS): ANALYSIS OF EXPOSURE PATHWAYS AND ROUTES FOR ARSENIC AND LEAD IN EPA REGION 5

    EPA Science Inventory

    The National Human Exposure Assessment Survey (NHEXAS) Phase I field study conducted in EPA Region 5 (Great Lakes Area) provides extensive exposure data on a representative sample of approximately 250 residents of the region. Associated environmental media and biomarker (blood...

  14. Lead exposure reduces carotenoid-based coloration and constitutive immunity in wild mallards.

    PubMed

    Vallverdú-Coll, Núria; Mougeot, François; Ortiz-Santaliestra, Manuel E; Rodriguez-Estival, Jaime; López-Antia, Ana; Mateo, Rafael

    2016-06-01

    The ingestion of spent lead (Pb) from ammunition is a known cause of mortality in waterfowl, but little is known about sublethal effects produced by Pb poisoning on birds, especially in wild populations. The authors studied potential sublethal effects associated with Pb exposure in mallards (Anas platyrhynchos) from the Ebro delta (northeastern Spain) after a ban on Pb ammunition. They analyzed the relationships between blood Pb levels and oxidative stress, immune response, and carotenoid-based coloration, which are known to be influenced by oxidative stress. Levels of Pb were reduced by half from 6 yr to 9 yr after the ban. Lipid peroxidation was positively related to Pb levels in females. The δ-aminolevulinic acid dehydratase activity was suppressed by Pb exposure and negatively associated with the activity of antioxidant enzymes. Carotenoid levels were positively associated with blood Pb concentration in both sexes, and males with higher Pb levels presented a less intense coloration in legs and beak. Levels of Pb were positively related to hemolytic activity of circulating immune system components and negatively related to lysozyme levels. In summary, Pb exposure was associated in a gender-specific way with increased oxidative stress, consequences on color expression, and impaired constitutive immunity. In females, antioxidants seemed to be allocated mostly in reproduction rather than in self-maintenance, whereas males seemed to better maintain oxidative balance to the detriment of coloration. Environ Toxicol Chem 2016;35:1516-1525. © 2015 SETAC. PMID:26551027

  15. Autophagy plays a protective role in cell death of osteoblasts exposure to lead chloride.

    PubMed

    Lv, Xiao-hua; Zhao, Da-hang; Cai, Shi-zhong; Luo, Shi-ying; You, Tingting; Xu, Bi-lian; Chen, Ke

    2015-12-01

    Lead (Pb) is a toxic heavy metal widespreadly used in industrial field. Prior studies showed that Pb exposure had detrimental effects on osteoblasts. The mechanisms underlying Pb-induced damage are complex. Autophagy can protect cells from various cytotoxic stimuli. In the present study, the aim of our research was to investigate whether Pb could activate autophagy to play a protective role against osteoblasts apoptosis. Our results indicated that PbCl2 induced autophagy and autophagic flux in MC3T3-E1 murine osteoblastic cell by RT-PCR, western blot, as well as fluorescence microscopy analysis of GFP-LC3, AO and MDC staining. Pb increased the apoptosis of osteoblasts, evidenced by western blot and Hoechst 33258 staining assessment. In addition, inhibiting autophagy by 3-MA further increased the osteoblasts apoptosis after Pb exposure, showed by flow cytometry and Hoechst 33258 staining. Furthermore, phosphorylation of mTOR and p70S6K was inhibited by Pb exposure, indicating that Pb might induce autophagy in osteoblasts via inhibiting mTOR pathway. Altogether, these evidence suggested that Pb exporsure promoted autophagy flux in osteoblasts. The activation of autophagy by Pb played a protective role in osteoblasts apoptosis, which might be mediated through the mTOR pathway. PMID:26383630

  16. Estimated lead (Pb) exposures for a population of urban community gardeners.

    PubMed

    Spliethoff, Henry M; Mitchell, Rebecca G; Shayler, Hannah; Marquez-Bravo, Lydia G; Russell-Anelli, Jonathan; Ferenz, Gretchen; McBride, Murray

    2016-08-01

    Urban community gardens provide affordable, locally grown, healthy foods and many other benefits. However, urban garden soils can contain lead (Pb) that may pose risks to human health. To help evaluate these risks, we measured Pb concentrations in soil, vegetables, and chicken eggs from New York City community gardens, and we asked gardeners about vegetable consumption and time spent in the garden. We then estimated Pb intakes deterministically and probabilistically for adult gardeners, children who spend time in the garden, and adult (non-gardener) household members. Most central tendency Pb intakes were below provisional total tolerable intake (PTTI) levels. High contact intakes generally exceeded PTTIs. Probabilistic estimates showed approximately 40 % of children and 10 % of gardeners exceeding PTTIs. Children's exposure came primarily from dust ingestion and exposure to higher Pb soil between beds. Gardeners' Pb intakes were comparable to children's (in µg/day) but were dominated by vegetable consumption. Adult household members ate less garden-grown produce than gardeners and had the lowest Pb intakes. Our results suggest that healthy gardening practices to reduce Pb exposure in urban community gardens should focus on encouraging cultivation of lower Pb vegetables (i.e., fruits) for adult gardeners and on covering higher Pb non-bed soils accessible to young children. However, the common practice of replacement of root-zone bed soil with clean soil (e.g., in raised beds) has many benefits and should also continue to be encouraged. PMID:26753554

  17. Alterations induced by chronic lead exposure on the cells of circadian pacemaker of developing rats

    PubMed Central

    Rojas-Castañeda, Julio César; Vigueras-Villaseñor, Rosa María; Rojas, Patricia; Chávez-Saldaña, Margarita; Pérez, Oscar Gutiérrez; Montes, Sergio; Ríos, Camilo

    2011-01-01

    Lead (Pb) exposure alters the temporal organization of several physiological and behavioural processes in which the suprachiasmatic nucleus (SCN) of the hypothalamus plays a fundamental role. In this study, we evaluated the effects of chronic early Pb exposure (CePbe) on the morphology, cellular density and relative optical density (OD) in the cells of the SCN of male rats. Female Wistar rats were exposed during gestation and lactation to a Pb solution containing 320 ppm of Pb acetate through drinking water. After weaning, the pups were maintained with the same drinking water until sacrificed at 90 days of age. Pb levels in the blood, hypothalamus, hippocampus and prefrontal cortex were significantly increased in the experimental group. Chronic early Pb exposure induced a significant increase in the minor and major axes and somatic area of vasoactive intestinal polypeptide (VIP)- and vasopressin (VP)-immunoreactive neurons. The density of VIP-, VP- and glial fibrillary acidic protein (GFAP)-immunoreactive cells showed a significant decrease in the experimental group. OD analysis showed a significant increase in VIP neurons of the experimental group. The results showed that CePbe induced alterations in the cells of the SCN, as evidenced by modifications in soma morphology, cellular density and OD in circadian pacemaker cells. These findings provide a morphological and cellular basis for deficits in circadian rhythms documented in Pb-exposed animals. PMID:21324006

  18. The effect of lead exposure on expression of SIRT1 in the rat hippocampus.

    PubMed

    Feng, Chang; Gu, Junwang; Zhou, Fankun; Li, Jiaoyang; Zhu, Gaochun; Guan, Linfu; Liu, Haizhen; Du, Guihua; Feng, Jiangao; Liu, Dong; Zhang, Shuyun; Fan, Guangqin

    2016-06-01

    Based on how the silent information regulator 2 homolog 1 (SIRT1) regulates the cyclic AMP response element binding protein (CREB), which is the molecular switch of long-term memory that maintains cognitive function, it is postulated that the impact of lead (Pb) on SIRT1 is one of the mechanisms leading to Pb-induced cognitive and learning deficits. Hence, the purpose of this study was to investigate the effect of Pb exposure on the expression of SIRT1, and the reversion effect of resveratrol, which is an activator of SIRT1. We examined the effects of maternal rat ingestion of Pb in drinking water during gestation and lactation on the expression of SIRT1 and CREB in the hippocampus of their offspring at postnatal week 3 (PNW3) and 52 (PNW52), and then reexamined these effects in offspring after intragastric administration of resveratrol for 4 weeks. Pb exposure decreased SIRT1 and CREB phosphorylation in a dose-dependent manner in the rat hippocampus at both PNW3 and 52, and resveratrol reversed those losses. These results indicated that SIRT1 might be a novel target to prevent Pb neurotoxicity. PMID:27131751

  19. Monitoring of zinc protoporphyrin levels in blood following occupational lead exposure

    SciTech Connect

    Wildt, K.; Berlin, M.; Isberg, P.E.

    1987-01-01

    The value of measurements of zinc protoporphyrin in blood (ZPP) in the surveillance of workers occupationally exposed to lead has been studied. From a group of referents, consisting of 1,088 men and 511 women, it has been established that the normal mean ZPP is in the region of 25 micrograms/100 ml, and only rarely do values exceed 45 micrograms/100 ml. The higher ZPP values are frequently associated with low blood hemoglobin concentrations and appear to be manifestations of an iron-deficiency anemia. Women have higher ZPP values than men; smoking has no influence. Measurements of ZPP and blood lead concentration (PbB) have been made every other month for 2.5 years on a group of around 200 men and 40 women exposed to lead in a storage battery factory. The mean ZPP of the group throughout the period was 70.9 micrograms/100 ml blood, and a linear relation between log ZPP and PbB in the PbB range of 10-80 micrograms/100 ml has been established. ZPP thresholds in the control of excessive occupational lead exposure, and the economic advantage of ZPP measurements over PbB, are discussed.

  20. Biomarkers of metals exposure in fish from lead-zinc mining areas of southeastern Missouri, USA.

    PubMed

    Schmitt, Christopher J; Whyte, Jeffrey J; Roberts, Aaron P; Annis, Mandy L; May, Thomas W; Tillitt, Donald E

    2007-05-01

    The potential effects of proposed lead-zinc mining in an ecologically sensitive area were assessed by studying a nearby mining district that has been exploited for about 30 y under contemporary environmental regulations and with modern technology. Blood and liver samples representing fish of three species (largescale stoneroller, Campostoma oligolepis, n=91; longear sunfish, Lepomis megalotis, n=105; and northern hog sucker, Hypentelium nigricans, n=20) from 16 sites representing a range of conditions relative to mining activities were collected. Samples were analyzed for metals (also reported in a companion paper) and for biomarkers of metals exposure [erythrocyte delta-aminolevulinic acid dehydratase (ALA-D) activity; concentrations of zinc protoporphyrin (ZPP), iron, and hemoglobin (Hb) in blood; and hepatic metallothionein (MT) gene expression and lipid peroxidation]. Blood lead concentrations were significantly higher and ALA-D activity significantly lower in all species at sites nearest to active lead-zinc mines and in a stream contaminated by historical mining than at reference or downstream sites. ALA-D activity was also negatively correlated with blood lead concentrations in all three species but not with other metals. Iron and Hb concentrations were positively correlated in all three species, but were not correlated with any other metals in blood or liver in any species. MT gene expression was positively correlated with liver zinc concentrations, but neither MT nor lipid peroxidase differences among fish grouped according to lead concentrations were statistically significant. ZPP was not detected by hematofluorometry in most fish, but fish with detectable ZPP were from sites affected by mining. Collectively, these results confirm that metals are released to streams from active lead-zinc mining sites and are accumulated by fish. PMID:17335901

  1. Studies on lead exposure in patients of a neighborhood health center: Part I. Pediatric patients.

    PubMed Central

    Blumenthal, H. T.; Flanigan, G. D.; Mayfield, R.

    1991-01-01

    A sharply focused study is presented defining the demographic characteristics of the catchment area of a St Louis health center and determining the blood lead (PbB) levels in children from 1977 to 1989. The sources of lead exposure are examined, and the adequacy of erythroprotoporphyrin (EP) determinations are evaluated to identify children with toxic levels. Mean PbB levels and prevalence rates at higher ranges were not only substantially higher in the catchment area population than in white children, but also significantly higher than in black children nationally. Since 1980, mean PbB declined progressively in the catchment area children, but it was not until 1989 that the mean PbB had declined to the 1980 level in white children nationally. PbB parameters in the catchment area children were not only higher than in children in other St Louis neighborhoods, but also higher than in children living in towns adjacent to a lead smelting operation. The environmental sources of lead considered here do not appear to fully account for the higher PbB levels in the children in the catchment area. Nutritional factors also need to be considered. Furthermore, the EP lacks both sensitivity and specificity for identifying children with PbB levels greater than or equal to 25 micrograms/dL and greater than or equal to 15 micrograms/dL. While this study identifies a community that has experiences a high prevalence of lead toxicity in its children, it also suggests that nationwide and even citywide estimates of the prevalence of lead toxicity based on EP screening may be significantly lower than actual prevalences. PMID:1813636

  2. Biomarkers of metals exposure in fish from lead-zinc mining areas of Southeastern Missouri, USA

    USGS Publications Warehouse

    Schmitt, C.J.; Whyte, J.J.; Roberts, A.P.; Annis, M.L.; May, T.W.; Tillitt, D.E.

    2007-01-01

    The potential effects of proposed lead-zinc mining in an ecologically sensitive area were assessed by studying a nearby mining district that has been exploited for about 30 y under contemporary environmental regulations and with modern technology. Blood and liver samples representing fish of three species (largescale stoneroller, Campostoma oligolepis, n=91; longear sunfish, Lepomis megalotis, n=105; and northern hog sucker, Hypentelium nigricans, n=20) from 16 sites representing a range of conditions relative to mining activities were collected. Samples were analyzed for metals (also reported in a companion paper) and for biomarkers of metals exposure [erythrocyte ??-aminolevulinic acid dehydratase (ALA-D) activity; concentrations of zinc protoporphyrin (ZPP), iron, and hemoglobin (Hb) in blood; and hepatic metallothionein (MT) gene expression and lipid peroxidation]. Blood lead concentrations were significantly higher and ALA-D activity significantly lower in all species at sites nearest to active lead-zinc mines and in a stream contaminated by historical mining than at reference or downstream sites. ALA-D activity was also negatively correlated with blood lead concentrations in all three species but not with other metals. Iron and Hb concentrations were positively correlated in all three species, but were not correlated with any other metals in blood or liver in any species. MT gene expression was positively correlated with liver zinc concentrations, but neither MT nor lipid peroxidase differences among fish grouped according to lead concentrations were statistically significant. ZPP was not detected by hematofluorometry in most fish, but fish with detectable ZPP were from sites affected by mining. Collectively, these results confirm that metals are released to streams from active lead-zinc mining sites and are accumulated by fish. ?? 2007 Elsevier Inc. All rights reserved.

  3. Studies on lead exposure in patients of a neighborhood health center: Part I. Pediatric patients

    SciTech Connect

    Blumenthal, H.T.; Flanigan, G.D. Jr.; Mayfield, R. )

    1991-12-01

    A sharply focused study is presented defining the demographic characteristics of the catchment area of a St Louis health center and determining the blood lead (PbB) levels in children from 1977 to 1989. The sources of lead exposure are examined, and the adequacy of erythroprotoporphyrin (EP) determinations are evaluated to identify children with toxic levels. Mean PbB levels and prevalence rates at higher ranges were not only substantially higher in the catchment area population than in white children, but also significantly higher than in black children nationally. Since 1980, mean PbB declined progressively in the catchment area children, but it was not until 1989 that the mean PbB had declined to the 1980 level in white children nationally. PbB parameters in the catchment area children were not only higher than in children in other St Louis neighborhoods, but also higher than in children living in towns adjacent to a lead smelting operation. The environmental sources of lead considered here do not appear to fully account for the higher PbB levels in the children in the catchment area. Nutritional factors also need to be considered. Furthermore, the EP lacks both sensitivity and specificity for identifying children with PbB levels greater than or equal to 25 micrograms/dL and greater than or equal to 15 micrograms/dL. While this study identifies a community that has experiences a high prevalence of lead toxicity in its children, it also suggests that nationwide and even citywide estimates of the prevalence of lead toxicity based on EP screening may be significantly lower than actual prevalences.

  4. Chemical form of selenium differentially influences DNA repair pathways following exposure to lead nitrate.

    PubMed

    McKelvey, Shauna M; Horgan, Karina A; Murphy, Richard A

    2015-01-01

    Lead, an environmental toxin is known to induce a broad range of physiological and biochemical dysfunctions in humans through a number of mechanisms including the deactivation of antioxidants thus leading to generation of reactive oxygen species (ROS) and subsequent DNA damage. Selenium on the other hand has been proven to play an important role in the protection of cells from free radical damage and oxidative stress, though its effects are thought to be form and dose dependent. As the liver is the primary organ required for metabolite detoxification, HepG2 cells were chosen to assess the protective effects of various selenium compounds following exposure to the genotoxic agent lead nitrate. Initially DNA damage was quantified using a comet assay, gene expression patterns associated with DNA damage and signalling were also examined using PCR arrays and the biological pathways which were most significantly affected by selenium were identified. Interestingly, the organic type selenium compounds (selenium yeast and selenomethionine) conferred protection against lead induced DNA damage in HepG2 cells; this is evident by reduction in the quantity of DNA present in the comet tail of cells cultured in their presence with lead. This trend also followed through the gene expression changes noted in DNA damage pathways analysed. These results were in contrast with those of inorganic sodium selenite which promoted lead induced DNA damage evident in both the comet assay results and the gene expression analysis. Over all this study provided valuable insights into the effects which various selenium compounds had on the DNA damage and signalling pathway indicating the potential for using organic forms of selenium such as selenium enriched yeast to protect against DNA damaging agents. PMID:25023848

  5. Combined exposure of Japanese quails to cyanotoxins, Newcastle virus and lead: oxidative stress responses.

    PubMed

    Paskova, Veronika; Veronika, Paskova; Paskerova, Hana; Hana, Paskerova; Pikula, Jiri; Jiri, Pikula; Bandouchova, Hana; Hana, Bandouchova; Sedlackova, Jana; Jana, Sedlackova; Hilscherova, Klara; Klara, Hilscherova

    2011-10-01

    Wild birds are continually exposed to many anthropogenic and natural stressors in their habitats. Over the last decades, mass mortalities of wild birds constitute a serious problem and may possibly have more causations such as natural toxins including cyanotoxins, parasitic diseases, industrial chemicals and other anthropogenic contaminants. This study brings new knowledge on the effects of controlled exposure to multiple stressors in birds. The aim was to test the hypothesis that influence of cyanobacterial biomass, lead and antigenic load may combine to enhance the effects on birds, including modulation of antioxidative and detoxification responses. Eight treatment groups of model species Japanese quail (Coturnix coturnix japonica) were exposed to various combinations of these stressors. The parameters of detoxification and oxidative stress were studied in liver and heart after 30 days of exposure. The antioxidative enzymatic defense in birds seems to be activated quite efficiently, which was documented by the elevated levels and activities of antioxidative and detoxification compounds and by the low incidence of damage to lipid membranes. The greatest modulations of glutathione level and activities of glutathione-S-transferase, glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase and lipid peroxidation were shown mostly in the groups with combined multiple exposures. The results indicate that the antioxidative system plays an important role in the protective response of the tissues to applied stressors and that its greater induction helps to protect the birds from more serious damage. Most significant changes of these "defense" parameters in case of multiple stressors suggest activation of this universal mechanism in situation with complex exposure and its crucial role in protection of the bird health in the environment. PMID:21855999

  6. History of Inuit Community Exposure to Lead, Cadmium, and Mercury in Sewage Lake Sediments

    PubMed Central

    Hermanson, Mark H.; Brozowski, James R.

    2005-01-01

    Exposure to lead, cadmium, and mercury is known to be high in many arctic Inuit communities. These metals are emitted from industrial and urban sources, are distributed by long-range atmospheric transport to remote regions, and are found in Inuit country foods. Current community exposure to these metals can be measured in food, but feces and urine are also excellent indicators of total exposure from ingestion and inhalation because a high percentage of each metal is excreted. Bulk domestic sewage or its residue in a waste treatment system is a good substitute measure. Domestic waste treatment systems that accumulate metals in sediment provide an accurate historical record of changes in ingestion or inhalation. We collected sediment cores from an arctic lake used for facultative domestic sewage treatment to identify the history of community exposure to Pb, Cd, and Hg. Cores were dated and fluxes were measured for each metal. A nearby lake was sampled to measure combined background and atmospheric inputs, which were subtracted from sewage lake data. Pb, Cd, and Hg inputs from sewage grew rapidly after the onset of waste disposal in the late 1960s and exceeded the rate of population growth in the contributing community from 1970 to 1990. The daily per-person Pb input in 1990 (720,000 ng/person per day) exceeded the tolerable daily intake level. The Cd input (48,000 ng/person per day) and Hg input (19,000 ng/person per day) were below the respective TDI levels at the time. PMID:16203239

  7. Structural equation modeling and nested ANOVA: Effects of lead exposure on maternal and fetal growth in rats

    SciTech Connect

    Hamilton, J.D. ); O'Flaherty, E.J.; Shukla, R.; Gartside, P.S. ); Ross, R. )

    1994-01-01

    This study provided an assessment of the effects of lead on early growth in rats based on structural equation modeling and nested analysis of variance (ANOVA). Structural equation modeling showed that lead in drinking water (250, 500, or 1000 ppm) had a direct negative effect on body weight and tail length (i.e., growth) in female rats during the first week of exposure. During the following 2 weeks of exposure, high correlation between growth measurements taken over time resulted in reduced early postnatal growth. By the fourth week of exposure, reduced growth was not evident. Mating began after 8 weeks of exposure, and exposure continued during gestation. Decreased fetal body weight was detected when the effects of litter size, intrauterine position, and sex were controlled in a nested ANOVA. Lead exposure did not appear to affect fetal skeletal development, possibly because lead did not alter maternal serum calcium and phosphorus levels. The effect of lead on individual fetal body weight suggests that additional studies are needed to examine the effect of maternal lead exposure on fetal development and early postnatal growth. 24 refs., 4 figs., 6 tabs.

  8. Immediate screening of lead exposure in the workplace using portable X-ray fluorescence.

    PubMed

    Gorce, Jean-Philippe; Roff, Martin

    2016-01-01

    The use of a portable X-ray fluorescence spectrometer (PXRF) equipped with a miniaturised X-ray tube producing a small 8 mm diameter X-ray beam required the validation of two new sampling protocols for the immediate screening of occupational lead exposure. First, lead in dust and fumes, collected by Institute of Occupational Medicine (IOM) inhalable samplers on 25 mm diameter membrane filters, is quantified using PXRF. To account for irregular dust deposition, the filters are rotated manually by quarter turns. Multiple PXRF readings are collected from the central region and from two locations in the outer region. The inner region is distinguishable from the outer region, but the two outer region locations are indistinguishable. High correlations (R(2) > 0.99) are found between the PXRF results and historical results obtained using a reference method based on a laboratory wavelength-dispersive sequential XRF instrument (WDXRF) for lead loadings between 1-161 μg. The PXRF results from the outer regions of the filters show a bias of -13% with respect to the WDXRF. Once this bias is allowed for, 95% of all PXRF results lie within -28% and +38% of the WDXRF results. Neither instrument accounts for potential dust accumulation on the walls of the IOM sampler. Therefore, methods based on their use can only be considered semi-quantitative. Second, a protocol combining direct PXRF measurements on workplace surfaces with surface wipes is designed for immediate on-site quantification of removable surface lead residues. The quantification of such residues by this method is compared with subsequent off-site wet chemistry analysis of the surface wipes. The two methods show a good correlation (R(2) ∼ 0.88). The ratio of the amount of removable residues determined by PXRF and wipe sampling is close to one with range 0.26-3.94. It is demonstrated that PXRF can be used as an effective tool for the immediate screening of occupational lead exposure. Although this article focused on

  9. Immediate screening of lead exposure in the workplace using portable X-ray fluorescence

    PubMed Central

    Gorce, Jean-Philippe; Roff, Martin

    2016-01-01

    ABSTRACT The use of a portable X-ray fluorescence spectrometer (PXRF) equipped with a miniaturised X-ray tube producing a small 8 mm diameter X-ray beam required the validation of two new sampling protocols for the immediate screening of occupational lead exposure. First, lead in dust and fumes, collected by Institute of Occupational Medicine (IOM) inhalable samplers on 25 mm diameter membrane filters, is quantified using PXRF. To account for irregular dust deposition, the filters are rotated manually by quarter turns. Multiple PXRF readings are collected from the central region and from two locations in the outer region. The inner region is distinguishable from the outer region, but the two outer region locations are indistinguishable. High correlations (R2 > 0.99) are found between the PXRF results and historical results obtained using a reference method based on a laboratory wavelength-dispersive sequential XRF instrument (WDXRF) for lead loadings between 1–161 μg. The PXRF results from the outer regions of the filters show a bias of −13% with respect to the WDXRF. Once this bias is allowed for, 95% of all PXRF results lie within −28% and +38% of the WDXRF results. Neither instrument accounts for potential dust accumulation on the walls of the IOM sampler. Therefore, methods based on their use can only be considered semi-quantitative. Second, a protocol combining direct PXRF measurements on workplace surfaces with surface wipes is designed for immediate on-site quantification of removable surface lead residues. The quantification of such residues by this method is compared with subsequent off-site wet chemistry analysis of the surface wipes. The two methods show a good correlation (R2 ∼ 0.88). The ratio of the amount of removable residues determined by PXRF and wipe sampling is close to one with range 0.26–3.94. It is demonstrated that PXRF can be used as an effective tool for the immediate screening of occupational lead exposure. Although this

  10. BIOLOGICAL INDICATOR OF SUMMATIONAL EXPOSURES TO LEAD. TOOTH LEAD IN CHILDREN LIVING IN CLEVELAND AND ITS SUBURBS

    EPA Science Inventory

    An epidemiologic study of the distribution of lead absorption in the Cleveland Metropolitan Area was carried out by analyzing the lead content of shed or extracted deciduous teeth of 11,241 children. Mean amounts of lead in teeth of children living in some suburbs were as high as...

  11. Occupational Lead Exposure and Associations with Selected Cancers: The Shanghai Men’s and Women’s Health Study Cohorts

    PubMed Central

    Liao, Linda M.; Friesen, Melissa C.; Xiang, Yong-Bing; Cai, Hui; Koh, Dong-Hee; Ji, Bu-Tian; Yang, Gong; Li, Hong-Lan; Locke, Sarah J.; Rothman, Nathaniel; Zheng, Wei; Gao, Yu-Tang; Shu, Xiao-Ou; Purdue, Mark P.

    2015-01-01

    Background Epidemiologic studies of occupational lead exposure have suggested increased risks of cancers of the stomach, lung, kidney, brain, and meninges; however, the totality of the evidence is inconsistent. Objective We investigated the relationship between occupational lead exposure and cancer incidence at the five abovementioned sites in two prospective cohorts in Shanghai, China. Methods Annual job/industry-specific estimates of lead fume and lead dust exposure, derived from a statistical model combining expert lead intensity ratings with inspection measurements, were applied to the lifetime work histories of participants from the Shanghai Women’s Health Study (SWHS; n = 73,363) and the Shanghai Men’s Health Study (SMHS; n = 61,379) to estimate cumulative exposure to lead fume and lead dust. These metrics were then combined into an overall occupational lead exposure variable. Cohort-specific relative hazard rate ratios (RRs) and 95% confidence intervals (CIs) comparing exposed and unexposed participants were estimated using Cox proportional hazards regression and combined by meta-analysis. Results The proportions of SWHS and SMHS participants with estimated occupational lead exposure were 8.9% and 6.9%, respectively. Lead exposure was positively associated with meningioma risk in women only (n = 38 unexposed and 9 exposed cases; RR = 2.4; 95% CI: 1.1, 5.0), particularly with above-median cumulative exposure (RR = 3.1; 95% CI: 1.3, 7.4). However, all 12 meningioma cases among men were classified as unexposed to lead. We also observed non-significant associations with lead exposure for cancers of the kidney (n = 157 unexposed and 17 ever exposed cases; RR = 1.4; 95% CI: 0.9, 2.3) and brain (n = 67 unexposed and 10 ever exposed cases; RR = 1.8; 95% CI: 0.7, 4.8) overall. Conclusions Our findings, though limited by small numbers of cases, suggest that lead is associated with the risk of several cancers in women and men. Citation Liao LM, Friesen MC, Xiang YB

  12. Stimulation of TRPC5 cationic channels by low micromolar concentrations of lead ions (Pb{sup 2+})

    SciTech Connect

    Sukumar, Piruthivi; Beech, David J.

    2010-02-26

    Lead toxicity is long-recognised but continues to be a major public health problem. Its effects are wide-ranging and include induction of hyper-anxiety states. In general it is thought to act by interfering with Ca{sup 2+} signalling but specific targets are not clearly identified. Transient receptor potential canonical 5 (TRPC5) is a Ca{sup 2+}-permeable ion channel that is linked positively to innate fear responses and unusual amongst ion channels in being stimulated by trivalent lanthanides, which include gadolinium. Here we show investigation of the effect of lead, which is a divalent ion (Pb{sup 2+}). Intracellular Ca{sup 2+} and whole-cell patch-clamp recordings were performed on HEK 293 cells conditionally over-expressing TRPC5 or other TRP channels. Extracellular application of Pb{sup 2+} stimulated TRPC5 at concentrations greater than 1 {mu}M. Control cells without TRPC5 showed little or no response to Pb{sup 2+} and expression of other TRP channels (TRPM2 or TRPM3) revealed partial inhibition by 10 {mu}M Pb{sup 2+}. The stimulatory effect on TRPC5 depended on an extracellular residue (E543) near the ion pore: similar to gadolinium action, E543Q TRPC5 was resistant to Pb{sup 2+} but showed normal stimulation by the receptor agonist sphingosine-1-phosphate. The study shows that Pb{sup 2+} is a relatively potent stimulator of the TRPC5 channel, generating the hypothesis that a function of the channel is to sense metal ion poisoning.

  13. Screening of lead exposure among workers in Selangor and Federal Territory in Malaysia.

    PubMed

    Surif, S; Chai, C Y

    1995-01-01

    The study of lead exposure among workers in Selangor and the Federal Territory was carried out based on the delta-aminolevulinic acid (ALA) level in urine. Occupations which are expected to have higher lead exposure were chosen in this research. The ALA level in the workers' urine was linked to a few variables which may contribute to the lead level in the body. The result of this study showed that the ALA level of the urine of university students (0.352 +/- 0.038 mg/100 ml) < clerical staff (0.560 +/- 0.043 mg/100 ml) < traffic police (0.612 +/- 0.064 mg/100 ml) < vehicle workshop workers (0.673 +/- 0.099 mg/100 ml) < petrol kiosk workers (0.717 +/- 0.069 mg/100 ml) < bus drivers/conductors (0.850 +/- 0.055 mg/100 ml) which was similar to workers in the printing industry (0.852 +/- 0.110 mg/100 ml). The ALA levels in the urine of the exposed workers were significantly different from the control group (university students). However, results obtained from clerical staff revealed that they were also in the exposed group category. Analysis of variance showed that the exposed groups are in a population which is different from the control population. Correlation tests suggest that there is no significant connection between the ALA level in the urine and the variables tested. Furthermore, Duncan's Multiple Range Test showed no significant differences between the smoking/non smoking group, alcoholic/non-alcoholic group, race and sex (p > 0.05). PMID:15091558

  14. Lead exposure from soil in Peruvian mining towns: a national assessment supported by two contrasting examples

    PubMed Central

    Bravo, Carolina; Gil, Vladimir; Sherpa, Shaky; Jack, Darby

    2012-01-01

    Abstract Objective To estimate the population of Peru living in the vicinity of active or former mining operations that could be exposed to lead from contaminated soil. Methods Geographic coordinates were compiled for 113 active mines, 138 ore processing plants and 3 smelters, as well as 7743 former mining sites. The population living within 5 km of these sites was calculated from census data for 2000. In addition, the lead content of soil in the historic mining town of Cerro de Pasco and around a recent mine and ore processing plant near the city of Huaral was mapped in 2009 using a hand-held X-ray fluorescence analyser. Findings Spatial analysis indicated that 1.6 million people in Peru could be living within 5 km of an active or former mining operation. Two thirds of the population potentially exposed was accounted for by 29 clusters of mining operations, each with a population of over 10 000 each. These clusters included 112 active and 3438 former mining operations. Soil lead levels exceeded 1200 mg/kg, a reference standard for residential soil, in 35 of 74 sites tested in Cerro de Pasco but in only 4 of 47 sites tested around the newer operations near Huaral. Conclusion Soil contamination with lead is likely to be extensive in Peruvian mining towns but the level of contamination is spatially far from uniform. Childhood exposure by soil ingestion could be substantially reduced by mapping soil lead levels, making this information public and encouraging local communities to isolate contaminated areas from children. PMID:23284193

  15. EFFECT OF LOW-LEVEL LEAD EXPOSURE ON PEDIATRIC NEUROBEHAVIORAL AND PHYSICAL DEVELOPMENT: CURRENT FINDINGS AND FUTURE DIRECTIONS

    EPA Science Inventory

    Studies of the relationship between lead exposure and the physical and neurobehavioral development of children constitute an important part of the scientific foundation for regulatory policies in many countries. The United States Environmental Protection Agency (U.S. EPA) recentl...

  16. Health status of cable splicers with low-level exposure to lead: results of a clinical survey

    SciTech Connect

    Fischbein, A.; Thornton, J.; Blumberg, W.E.

    1980-07-01

    The results of a cross-sectional clinical field survey of 90 telephone cable splicers are presented. Despite the rare occurrence of clinically overt lead poisoning among cable splicers, the observed prevalence of symptoms was 29% for lead-associated central nervous system symptoms and 21% for gastrointestinal symptoms. These two groups of symptoms were directly related to zinc protoporphyrin (ZPP) levels but no relationship was found between them and blood lead concentrations. Only 5% of the workers had significantly elevated blood lead levels (> 40 ..mu..g/100 ml). Because of the intermittent lead exposure encountered in this trade, individuals were identified with normal blood lead levels associated with elevated zinc protoporphyrin concentrations, indicating the difference in biological significance between exposure-(blood lead) and biological-response tests (ZPP). Suggestion is made that both types of diagnostic tests be utilized in the medical surveillance of lead-exposed workers.

  17. Hand Self-Wiping Protocol for the Investigation of Lead Exposure in the Workplace

    PubMed Central

    Gorce, Jean-Philippe; Roff, Martin

    2015-01-01

    The purpose of this project was to develop and validate a hand wiping protocol to be used by occupational hygienists, scientists, or other competent persons, measuring skin exposure to lead in workplaces. Inadvertent lead ingestion is likely to occur once the hands of employees have become contaminated. Ideally, a hand wiping protocol should maximize the recovery of lead-based residues present on employees’ hands in a cost-effective and reproducible manner. This article describes an effective and practical hand wiping procedure. Here, two standardized protocols (A and B) are designed. Protocol A is a self-wiping protocol requiring employees to wipe their own hands using four separate and successive wipes. Protocol B involves a scientist wiping the hands of employees using four wipes, followed by employees self-wiping their hands using two wipes (total of six wipes). Both protocols are defined by four wipe passes over each hand using Ghost wipes. Because this study took place in the workplace rather than in a simulated laboratory environment, only the relative (i.e., not absolute) removal efficiencies of the hand wiping protocols have been assessed. The two protocols were first evaluated at a double glazing panel manufacturing site where between 248 μg and 4544 μg of lead was found on employees’ hands. A statistical analysis (t-test) on the mean relative lead levels recovered in the first parts of the protocols indicated that Protocol A was more efficient than Protocol B (73% for Protocol A vs. 65% for Protocol B). The relative recovery of the combined first two passes against the combined first three passes also confirmed the greater efficiency of Protocol A (83.3% for Protocol A vs. 76.5% for Protocol B). However, lead levels recovered on the fourth pass remain significant at more than 10% of the total recovered loadings. Nonetheless, Protocol A was preferred and further evaluated at a lead battery manufacturing site where between 149 μg and 18,784

  18. Risks to children from exposure to lead in air during remedial or removal activities at Superfund sites: a case study of the RSR lead smelter Superfund site.

    PubMed

    Khoury, Ghassan A; Diamond, Gary L

    2003-01-01

    Superfund sites that are contaminated with lead and undergoing remedial action generate lead-enriched dust that can be released into the air. Activities that can emit lead-enriched dust include demolition of lead smelter buildings, stacks, and baghouses; on-site traffic of heavy construction vehicles; and excavation of soil. Typically, air monitoring stations are placed around the perimeter of a site of an ongoing remediation to monitor air lead concentrations that might result from site emissions. The National Ambient Air Quality (NAAQ) standard, established in 1978 to be a quarterly average of 1.5 microg/m(3), is often used as a trigger level for corrective action to reduce emissions. This study explored modeling approaches for assessing potential risks to children from air lead emissions from the RSR Superfund site in West Dallas, TX, during demolition and removal of a smelter facility. The EPA Integrated Exposure Uptake Biokinetic (IEUBK) model and the International Commission of Radiologic Protection (ICRP) lead model were used to simulate blood lead concentrations in children, based on monitored air lead concentrations. Although air lead concentrations at monitoring stations located in the downwind community intermittently exceeded the NAAQ standard, both models indicated that exposures to children in the community areas did not pose a significant long-term or acute risk. Long-term risk was defined as greater than 5% probability of a child having a long-term blood lead concentration that exceeded 10 microg/dl, which is the CDC and the EPA blood lead concern level. Short-term or acute risk was defined as greater than 5% probability of a child having a blood lead concentration on any given day that exceeded 20 microg/dl, which is the CDC trigger level for medical evaluation (this is not intended to imply that 20 microg/dl is a threshold for health effects in children exposed acutely to airborne lead). The estimated potential long-term and short-term exposures

  19. Lead exposure, begun in utero, decreases renin and angiotensin II in adult rats

    SciTech Connect

    Victery, W.; Vander, A.J.; Markel, H.; Katzman, L.; Shulak, J.M.; Germain, C.

    1982-05-01

    Male rats were exposed continously to Pb in utero and after birth by giving their mothers, during pregnancy and lactation, drinking water containing 0, 5, or 25 ppm Pb (as Pb acetate) and then continuing this regimen after weaning for approximately 5 months. At the time of sacrifice (5 months) the 5- and 25-ppm groups had mean blood Pb concentrations of 5.6 and 18.2 ..mu..g/dl, respectively. No differences in systolic blood pressure occurred between groups. Rats exposed to 25 ppm manifested a significant decrease in basal plasma renin activity (PRA) but a significant increase in PRA during stimulation of renin release by acute volume depletion. In this latter state, the ratio of angiotensin II to PRA was significantly reduced in the 25-ppm group. Groups exposed to 5 and 25 ppm both had significant decreases in renal renin concentration. We conclude that chronic exposure of rats to doses of Pb which produce blood Pb concentrations similar to those generally present in urban human populations does not induce hypertension but does inhibit renin synthesis and release, as well as reducing plasma angiotension II concentration at any given PRA, either by inhibiting conversion of AI to AII or by enhancing AII catabolism.

  20. Human exposure to mercury, lead and cadmium through consumption of canned mackerel, tuna, pilchard and sardine.

    PubMed

    Okyere, H; Voegborlo, R B; Agorku, S E

    2015-07-15

    Total mercury (Hg), cadmium (Cd) and lead (Pb) concentrations were determined in canned fish on the Ghanaian market. Total mercury was determined using an automatic mercury analyzer while cadmium and lead levels were determined by flame atomic absorption spectrophotometry. The metal contents in the samples, expressed in μg g(-1) (wet weight), varied from <0.01 to 0.20 with an average value of 0.03 for mercury, from <0.01 to 0.45 with an average value of 0.34 for cadmium, and from <0.01 to 1.44 with an average value of 0.72 for lead. The results indicate that canned fish from the Ghanaian market have concentrations well below the permissible FAO/WHO for these toxic metals. Thus considering the Provisional Tolerable Weekly Intake (PTWI) of Hg, Pb and Cd the levels obtained in this study are unlikely to constitute a significant exposure to the public through consumption of moderate amounts. PMID:25722173

  1. The efficacy of protoporphyrin as a predictive biomarker for lead exposure in canvasback ducks: effect of sample storage time

    USGS Publications Warehouse

    Franson, J.C.; Hohman, W.L.; Moore, J.L.; Smith, M.R.

    1996-01-01

    We used 363 blood samples collected from wild canvasback ducks (Aythya valisineria) at Catahoula Lake, Louisiana, U.S.A. to evaluate the effect of sample storage time on the efficacy of erythrocytic protoporphyrin as an indicator of lead exposure. The protoporphyrin concentration of each sample was determined by hematofluorometry within 5 min of blood collection and after refrigeration at 4 °C for 24 and 48 h. All samples were analyzed for lead by atomic absorption spectrophotometry. Based on a blood lead concentration of ≥0.2 ppm wet weight as positive evidence for lead exposure, the protoporphyrin technique resulted in overall error rates of 29%, 20%, and 19% and false negative error rates of 47%, 29% and 25% when hematofluorometric determinations were made on blood at 5 min, 24 h, and 48 h, respectively. False positive error rates were less than 10% for all three measurement times. The accuracy of the 24-h erythrocytic protoporphyrin classification of blood samples as positive or negative for lead exposure was significantly greater than the 5-min classification, but no improvement in accuracy was gained when samples were tested at 48 h. The false negative errors were probably due, at least in part, to the lag time between lead exposure and the increase of blood protoporphyrin concentrations. False negatives resulted in an underestimation of the true number of canvasbacks exposed to lead, indicating that hematofluorometry provides a conservative estimate of lead exposure.

  2. Lead exposure and toxicity bioassays: Public health and occupational health. (Latest citations from the Biobusiness database). Published Search

    SciTech Connect

    Not Available

    1993-05-01

    The bibliography contains citations concerning the effects of chronic lead exposure on the job and at home on both children and adults. Biochemical assays for the measurement of blood and tissue lead levels are presented. Synergistic effects of lead and other pollutants such as cigarette smoke, other metals, and sulfer dioxide are examined. Natural and manmade sources of lead in the environment are discussed. (Contains 250 citations and includes a subject term index and title list.)

  3. Effects of dietary lead exposure on vitamin levels in great tit nestlings - An experimental manipulation.

    PubMed

    Ruiz, Sandra; Espín, Silvia; Rainio, Miia; Ruuskanen, Suvi; Salminen, Juha-Pekka; Lilley, Thomas M; Eeva, Tapio

    2016-06-01

    Exposure to metal pollution negatively affects animal physiology, including nutrient metabolism, but in the wild an effect can seldom be attributed to a single metal. Moreover, little is known about how the metabolism of vitamins, essential micronutrients for developing juveniles, is affected by toxic metals. Therefore we experimentally investigated the effects of lead (Pb), a widespread toxic metal, on four fat-soluble vitamins A (total and retinol), D3, E (total and α-tocopherol) and K and carotenoids (lutein, zeaxanthin and unidentified) in great tit (Parus major) nestlings. In addition to a control group where no Pb was provided, two Pb-dosed groups were compared to a metal exposed group in the vicinity of a Ni-Cu smelter. We examined whether Pb treatment affects vitamin homeostasis and how the response of Pb-treated birds relates to that of a population under industrial exposure of Pb and other metals. For this purpose, vitamin and carotenoid levels were quantified with UPLC-MS from plasma of 7 days-old nestlings. All metal exposed groups showed increased vitamin A and retinol levels. However, vitamin levels were not directly associated with fecal Pb levels, with the exception of retinol, which was positively correlated with fecal Pb. Alpha-tocopherol, lutein and zeaxanthin levels were positively associated with body mass and wing growth rate. To conclude, Pb exposure increased plasma vitamin A and retinol levels while the levels of other vitamins and carotenoids rather reflected secondary pollution effects via differences in habitat and diet quality at the smelter site. Our findings suggest Pb exposed nestlings may allocate the vitamins needed for growth and development to fight the physiological stress thus compromising their fitness. PMID:27023278

  4. Exposure of C. elegans eggs to a glyphosate-containing herbicide leads to abnormal neuronal morphology.

    PubMed

    McVey, Kenneth A; Snapp, Isaac B; Johnson, Megan B; Negga, Rekek; Pressley, Aireal S; Fitsanakis, Vanessa A

    2016-01-01

    Recent data demonstrate that chronic exposure of Caenorhabditis elegans (C. elegans) to a high-use glyphosate-containing herbicide, Touchdown (TD), potentially damages the adult nervous system. It is unknown, however, whether unhatched worms exposed to TD during the egg stage show abnormal neurodevelopment post-hatching. Therefore, we investigated whether early treatment with TD leads to aberrant neuronal or neurite development in C. elegans. Studies were completed in three different worm strains with green fluorescent protein (GFP)-tagged neurons to facilitate visual neuronal assessment. Initially, eggs from C. elegans with all neurons tagged with GFP were chronically exposed to TD. Visual inspection suggested decreased neurite projections associated with ventral nerve cord neurons. Data analysis showed a statistically significant decrease in overall green pixel numbers at the fourth larval (L4) stage (*p<0.05). We further investigated whether specific neuronal populations were preferentially vulnerable to TD by treating eggs from worms that had all dopaminergic (DAergic) or γ-aminobutyric acid (GABAergic) neurons tagged with GFP. As before, green pixel number associated with these discrete neuronal populations was analyzed at multiple larval stages. Data analysis indicated statistically significant decreases in pixel number associated with DAergic, but not GABAergic, neurons (***p<0.001) at all larval stages. Finally, statistically significant decreases (at the first larval stage, L1) or increases (at the fourth larval stage, L4) in superoxide levels, a developmental signaling molecule, were detected (*p<0.05). These data suggest that early exposure to TD may impair neuronal development, perhaps through superoxide perturbation. Since toxic insults during development may late render individuals more vulnerable to neurodegenerative diseases in adulthood, these studies provide some of the first evidence in this model organism that early exposure to TD may adversely

  5. Updated estimates of earnings benefits from reduced exposure of children to environmental lead

    SciTech Connect

    Salkever, D.S.

    1995-07-01

    The recent and important study by Schwartz found that almost three-fourths of the benefits of reduced lead exposure in children are in the form of earnings gains (earnings losses avoided). New data on recent trends in returns to education and cognitive skills in the labor market suggest a need to revise this estimate upward. Based on an analysis of data from the National Longitudinal Survey of Youth, the present study estimates that an upward revision of at least 50% (or $2.5 billion per annual birth cohort) is indicated. The study also finds evidence that percentage earnings gains are considerably larger for females than for males. 21 refs., 1 fig., 2 tabs.

  6. Occupational and environmental lead exposure to adolescent workers in battery recycling workshops.

    PubMed

    Kazi, Tasneem Gul; Shah, Faheem; Afridi, Hassan Imran; Naeemullah

    2015-12-01

    Lead (Pb), as other environmental neurotoxicant substances, has the capability to interfere with many biochemical events present in cells throughout the body. In the present study, the environmental and occupational exposure to Pb has been assessed by analyzing the scalp hair samples of male adolescents aged 12-15 years, who have worked for the last 12-36 months in Pb battery recycling workshops (BRWs). For comparative purposes, gender and age-matched subjects living in the vicinity of recycling workshops as well as in areas without industrial activity were used as controls. The scalp hair samples were oxidized by acid in a microwave oven prior to determination of Pb by electrothermal atomic absorption spectrometry. The results indicated that both workers and nonworking exposed subjects had higher levels of Pb than nonexposed controls. The contents of Pb in scalp hair of adolescent workers in the present study were compared with those reported in other studies. PMID:23823616

  7. The pros and cons of intraoperative CT scan in evaluation of deep brain stimulation lead implantation: A retrospective study

    PubMed Central

    Servello, Domenico; Zekaj, Edvin; Saleh, Christian; Pacchetti, Claudio; Porta, Mauro

    2016-01-01

    Background: Deep brain stimulation (DBS) is an established therapy for movement disorders, such as Parkinson's disease (PD), dystonia, and tremor. The efficacy of DBS depends on the correct lead positioning. The commonly adopted postoperative radiological evaluation is performed with computed tomography (CT) scan and/or magnetic resonance imaging (MRI). Methods: We conducted a retrospective study on 202 patients who underwent DBS from January 2009 to October 2013. DBS indications were PD, progressive supranuclear palsy, tremor, dystonia, Tourette syndrome, obsessive compulsive disorder, depression, and Huntington's disease. Preoperatively, all patients underwent brain MRI and brain CT scan with the stereotactic frame positioned. The lead location was confirmed intraoperatively with CT. The CT images were subsequently transferred to the Stealth Station Medtronic and merged with the preoperative planning. On the first or second day after, implantation we performed a brain MRI to confirm the correct position of the lead. Results: In 14 patients, leads were in suboptimal position after intraoperative CT scan positioning. The cases with alteration in the Z-axis were corrected immediately under fluoroscopic guidance. In all the 14 patients, an immediate repositioning was done. Conclusions: Based on our data, intraoperative CT scan is fast, safe, and a useful tool in the evaluation of the position of the implanted lead. It also reduces the patient's discomfort derived from the transfer of the patient from the operating room to the radiological department. However, intraoperative CT should not be considered as a substitute for postoperative MRI. PMID:27583182

  8. Effect of combined exposure to lead and decabromodiphenyl ether on neurodevelopment of zebrafish larvae.

    PubMed

    Zhu, Biran; Wang, Qiangwei; Shi, Xiongjie; Guo, Yongyong; Xu, Tao; Zhou, Bingsheng

    2016-02-01

    The effect of combined exposure to decabromodiphenyl ether (BDE-209) and lead (Pb) on neurodevelopment of zebrafish (Danio rerio) larvae was investigated. Zebrafish embryos were exposed to Pb (0, 5, 10, 20 µg/L) and BDE-209 (0, 50, 100, 200 µg/L), either alone or in combination (Mix1: 5 + 50 µg/L, Mix2: 10 + 100 µg/L, Mix3: 20 + 200 µg/L) for up to 144 h post-fertilization. Growth of secondary motoneuron axons and expression of genes related to central nervous system development was significantly inhibited in Mix3 co-exposure group. A significant increase in reactive oxygen species (ROS), lipid peroxidation, DNA damage, and perturbation of the antioxidant system was detected in the Mix3 group compared to single-toxicant treatments or control. Depressed locomotor activity was recorded in the Mix2 and Mix3 groups. Addition of N-acetyl cysteine to Mix3 eliminated excessive ROS, and protected against lipid peroxidation, DNA damage, and locomotor dysfunction. Pb uptake was increased in the presence of BDE-209, but BDE-209 bioconcentration and the ability to metabolize BDE-209 were decreased in the presence of Pb. These results suggest that BDE-209 and Pb have a synergistic disruptive effect on neurodevelopment in zebrafish larvae by enhanced generation of ROS, which is a major factor that contributes to developmental neurotoxicity. PMID:26519795

  9. Physiological effects of waterborne lead exposure in spiny dogfish (Squalus acanthias).

    PubMed

    Eyckmans, Marleen; Lardon, Isabelle; Wood, Chris M; De Boeck, Gudrun

    2013-01-15

    To broaden our knowledge about the toxicity of metals in marine elasmobranchs, cannulated spiny dogfish (Squalus acanthias) were exposed to 20 μM and 100 μM lead (Pb). Since we wanted to focus on sub lethal ion-osmoregulatory and respiratory disturbances, arterial blood samples were analysed for pH(a), PaO(2), haematocrit and total CO(2) values at several time points. Plasma was used to determine urea, TMAO, lactate and ion concentrations. After 96 h, Pb concentrations were determined in a number of tissues, such as gill, rectal gland, skin and liver. To further investigate ion and osmoregulation, Na(+)/K(+)-ATPase activities in gill and rectal gland were analysed as well as rates of ammonia and urea excretion. Additionally, we studied the energy reserves in muscle and liver. Pb strongly accumulated in gills and especially in skin. Lower accumulation rates occurred in gut, kidney and rectal gland. A clear disturbance in acid-base status was observed after one day of exposure indicating a transient period of hyperventilation. The increase in pH(a) was temporary at 20 μM, but persisted at 100 μM. After 2 days, plasma Na and Cl concentrations were reduced compared to controls at 100 μM Pb and urea excretion rates were elevated. Pb caused impaired Na(+)/K(+)-ATPase activity in gills, but not in rectal gland. We conclude that spiny dogfish experienced relatively low ion-osmoregulatory and respiratory distress when exposed to lead, particularly when compared to effects of other metals such as silver. These elasmobranchs appear to be able to minimize the disturbance and maintain physiological homeostasis during an acute Pb exposure. PMID:23063001

  10. Metabolic model of lead kinetics based upon measured organ burdens during chronic exposure experiments with infant and juvenile baboons

    SciTech Connect

    Mallon, R.P.

    1983-01-01

    A mathematical model of the kinetics of lead metabolism in the infant and juvenile baboon has been developed based upon data from chronic exposure experiments in this non-human primate. The model of lead metabolism presents in quantitative terms the rates of uptake, distribution and elimination that lead may undergo during its passage through the organism. The organs of accumulation are defined as compartments, each of which is defined as a quantity of tissue that behaves kinetically like a distinct, homogeneous, well mixed pool in terms of lead concentration. The flow of lead between the compartments of accumulation is described by a series of differential equations. Elimination rate coefficients, expressed in terms of the biological half-life for each compartment have been estimated. The model describes the observed build-up and accumulation of lead in the major body compartments of the infant and juvenile baboon. The model indicates that: the biological half-life of lead in blood of the very young animals is shorter than that of the older animals; there is a higher rate of uptake of lead in the soft tissues and in the bones of rapidly growing animals; and there is an inverse relationship between the quality of lead administered and the amount of lead absorbed, i.e., as exposure increases the rate of absorption decreases. The model derived for the older animals accurately predicts the accumulation and retention of lead in adult humans under normal exposure conditions.

  11. Stimulated Raman scattering in lead vapor heat pipe for tunable and narrow-linewidth XeCl excimer laser

    SciTech Connect

    Rieger, H.

    1989-05-01

    Narrow-linewidth and high-efficiency conversion of stimulated Raman scattering (SRS) in a lead vapor heat pipe was observed using a narrow-linewidth and injection-locked XeCl excimer laser system as the pump source. The XeCl laser was continuously tuned over its entire B-X gain curve, from the (0-0) transition to the (0-3) transition, giving it a range of 0.8 nm (307.65-308.45 nm). The laser linewidth was narrowed down to 0.002 A (0.02 cm/sup -1/). The output energy was 310 mJ/pulse, with a repetition rate up to 50 pps and good beam quality. A lead vapor heat pipe operating at 1225/sup 0/C was used as a single-pass stimulated Raman converter, shifting the radiation from 308 to 459 nm. Photon conversion efficiency as high as 80 percent was achieved, using a pump linewidth of 0.01 A.

  12. [Social conditions of the exposure to environmental lead observed in children from Piekary Slaskie].

    PubMed

    Szymik, Ewa

    2004-01-01

    The aim of the paper was to evaluate the social conditions of the exposure to environmental lead observed in children from Piekary Slaskie, the patients of The Environmental Health Outpatient Department. The examinations were conducted in 1995, in 183 children: 95 (52%) girls and 88 (48%) boys, which is 5.3% of the total population of children aged 3-12 living in the districts of Piekary Slaskie with the higher risk of lead intoxication: Brzeziny Slaskie, Dabrówka Wielka and Brzozowice-Kamień. The examinations were conducted in the period of April and May. They comprised the following parameters: environmental and paediatric interview, physical examination--evaluation of total condition of the child, and laboratory determination of lead concentration in blood with the method of atomic flameless spectrophotometry. The collected data was statistically elaborated with the use of the "STATISTICA 5.1 PL" programme in the Computer Laboratory at the Silesian Engineering College in Katowice. In 1995 the average lead concentration in blood of 183 children from Piekary Slaskie aged 3-12 ranged from 2.2 to 39.6 microg/dl, and the average population concentration was of 8.22 microg/dl SD: 4.7 microg/dl. Significantly higher average lead concentration in blood was observed in nursery children aged 3-4 (9.56 microg/dl SD: 4.2 microg/dl) when compared to school children (7.4 microg/dl SD: 3.8 microg/dl). In the examined population 19.8% of children crossed the level of 10.0 microg/dl. The conclusions of the examinations may be as follows: bad social-economic conditions (especially unemployment and pathology of families), hygienic customs and nutrition habits of the native population of Piekary Slaskie as well as only the primary or professional education of parents influence the rise in average lead concentration in blood at nursery and school children. PMID:15682943

  13. Genetical Toxicogenomics in Drosophila Identifies Master Modulatory Loci that are Regulated by Developmental Exposure to Lead

    PubMed Central

    Ruden, Douglas M.; Chen, Lang; Possidente, Debra; Possidente, Bernard; Rasouli, Parsa; Wang, Luan; Lu, Xiangyi; Garfinkel, Mark D.; Hirsch, Helmut V. B.; Page, Grier P.

    2009-01-01

    The genetics of gene expression in recombinant inbred lines (RILs) can be mapped as expression quantitative trait loci (eQTLs). So-called “genetical genomics” studies have identified locally-acting eQTLs (cis-eQTLs) for genes that show differences in steady state RNA levels. These studies have also identified distantly-acting master-modulatory trans-eQTLs that regulate tens or hundreds of transcripts (hotspots or transbands). We expand on these studies by performing genetical genomics experiments in two environments in order to identify trans-eQTL that might be regulated by developmental exposure to the neurotoxin lead. Flies from each of 75 RIL were raised from eggs to adults on either control food (made with 250 µM sodium acetate), or lead-treated food (made with 250 µM lead acetate, PbAc). RNA expression analyses of whole adult male flies (5–10 days old) were performed with Affymetrix DrosII whole genome arrays (18,952 probesets). Among the 1,389 genes with cis-eQTL, there were 405 genes unique to control flies and 544 genes unique to lead-treated ones (440 genes had the same cis-eQTLs in both samples). There are 2,396 genes with trans-eQTL which mapped to 12 major transbands with greater than 95 genes. Permutation analyses of the strain labels but not the expression data suggests that the total number of eQTL and the number of transbands are more important criteria for validation than the size of the transband. Two transbands, one located on the 2nd chromosome and one on the 3rd chromosome, co-regulate 33 lead-induced genes, many of which are involved in neurodevelopmental processes. For these 33 genes, rather than allelic variation at one locus exerting differential effects in two environments, we found that variation at two different loci are required for optimal effects on lead-induced expression. PMID:19737576

  14. Lead risk assessment for children in Hungary by predicting their blood lead levels using US EPA integrated Exposure Uptake Biokinetic model.

    PubMed

    Hassanien, M A; Horváth, A

    1999-08-01

    The US EPA integrated Exposure Uptake Biokinetic (IEUBK 0.99d) lead exposure for children was validated, updated, and applied to predict mean blood lead levels based on lead uptake from multiple sources and provide assessment of risk. Surveys were carried out around houses in a polluted area (Heves, Hungary) in 1995. The collected data from that area have shown very high levels of lead in soil. In some cases the level of lead in soil has reached more than 1000 times the allowable limit value used (100 mg/kg) in Hungary. Moreover, the concentration of lead in air was measured and the concentration of lead in air varied from 0.05-1.83 micrograms/m3. The environmental data within the community were used to predict the children blood lead levels and to compare the observed estimates with the other predicted ones. The age of the investigated group of children varied from 0-60 months. The estimated blood lead levels have illustrated variation according to age, sex, and the specific site. It can be concluded from this study that the model can be used on a wide range to give us an excellent picture for site cleanup, to decision makers, and finally to use the environmental data to predict blood lead level for the community or population. Results of several validation exercises utilizing the IEUBK model comparing predicted and measured blood lead levels with international guidelines and the percent of risk of exceeding a specific blood lead level (i.e., 10 micrograms/dl) are presented in this paper. PMID:10499150

  15. Condition and type of housing as an indicator of potential environmental lead exposure and pediatric blood lead levels

    SciTech Connect

    Clark, C.S.; Bornschein, R.L.; Succop, P.; Que Hee, S.S.; Hammond, P.B.; Peace, B.

    1985-10-01

    Environmental evaluations in a prospective behavior study of children with blood lead levels up to about 50 g/dl were performed by an intensive environmental survey and by exterior visual evaluations of housing quality. Serial blood lead values for infants in the study were compared to exterior housing type and quality, which itself was also compared with results of the intensive environmental evaluation. Five housing condition and type categories were defined: public housing; private housing (satisfactory, deteriorated, and dilapidated); and rehabilitated private housing. In this interim report on the first subset of available data, the housing categories were found to differ in paint and environment dust lead levels, with public and rehabilitated housing having lowest values. Blood lead concentrations of children differed across housing categories as early as 6 months of age, with children residing in public housing having lowest levels, followed by those in rehabilitated housing. The spread in mean blood lead concentrations among the housing quality categories increased with increasing age of the children. Housing category accounted for over one-half of the blood lead variability in 18-month-old children.

  16. No delayed behavioral and phenotypic responses to experimental early-life lead exposure in great tits (Parus major).

    PubMed

    Ruuskanen, Suvi; Eeva, Tapio; Kotitalo, Päivi; Stauffer, Janina; Rainio, Miia

    2015-02-01

    Early-life exposure to pollutants, such as lead, may have long-lasting consequences on health, behavior, and cognition. However, experiments on delayed effects of specific pollutants are very rare in wild animals. We experimentally exposed wild nestling great tits (Parus major) to dietary lead (high, low, or control group) in levels relevant to exposure levels of wild populations in Europe and studied delayed effects on phenotypic and behavioral traits in captivity. We also included a group of birds from a vicinity of a copper smelter, exposed to a mixture of toxic metals and altered food supply during development. This experimental setup allowed us to compare the strength of direct (exposure to lead per se) and indirect (pollution-related changes in diet) effects of pollutants. Our experimental lead treatment significantly increased lead levels in bone and feces compared with controls. However, we found no carry-over effect of early-life dietary lead on morphology, plumage coloration, or heat shock proteins. Treatment did not affect activity, exploration, neophobia, or success in learning and spatial memory task. We conclude that with the exposure levels and relatively short exposure period used, delayed effects on the measured traits were not found. However, it is important to further study other types of behavioral traits and ultimately fitness effects. PMID:25194842

  17. An ecological risk assessment of lead shot exposure in non-waterfowl avian species: Upland game birds and raptors

    SciTech Connect

    Kendall, R.J.; Lacher, T.E. Jr.; Bunck, C.

    1996-01-01

    There is increasing concern that birds in terrestrial ecosystems may be exposed to spent lead shot. Evidence exists that upland birds, particularly mourning doves (Zenaida macroura), ingest spent lead shot and that raptors ingest lead shot by consuming wounded game. Mortality, neurological dysfunction, immune suppression, and reproductive impairment are documented effects of exposure to lead in birds. An ecological risk assessment on the impact of lead shot exposure in upland birds was conducted and is presented in the context of the new United States Environmental Protection Agency`s Ecological Risk Assessment Paradigm. A considerable amount of spent lead shot is released into the environment each year from shooting and hunting. Doves collected from fields that are cultivated to attract mourning doves for hunting activities show evidence of ingestion of spent lead shot. Because lead can cause both acute and chronic toxicity if ingested by birds, and because there is evidence of widespread deposition of lead shot in terrestrial ecosystems, concern for impacts on upland game birds and raptors seems warranted. Although this ecological risk assessment does not clearly define a significant risk of lead shot exposure to upland game birds, this issue merits continued scrutiny to protect upland game bird and raptor resources.

  18. Using a mobile transparent plastic-lead-boron shielding barrier to reduce radiation dose exposure in the work place

    SciTech Connect

    Parra, S A; Mecozzi, J M

    2001-01-11

    Moveable radiation shielding barriers made of plastic material containing lead and boron can be used to reduce radiation exposure near the work place. Personnel can maneuver and position the transparent radiation shielding barriers anywhere within the work place. The lead in the shielding barrier provides an effective shielding material against radiation exposure (approximately a 1.0 mm lead equivalent protection) while the boron in the shielding barrier provides neutron absorption to reduce the moderation/reflection effects of the shielding materials (approximately a 2% {Delta}k/k reduction).

  19. Effects of copper and lead exposure on the ecophysiology of the brown seaweed Sargassum cymosum.

    PubMed

    Costa, Giulia Burle; de Felix, Marthiellen R L; Simioni, Carmen; Ramlov, Fernanda; Oliveira, Eva Regina; Pereira, Débora T; Maraschin, Marcelo; Chow, Fungyi; Horta, Paulo Antunes; Lalau, Cristina Moreira; da Costa, Cristina H; Matias, William Gerson; Bouzon, Zenilda L; Schmidt, Éder C

    2016-01-01

    The effects of the heavy metals copper (Cu) and lead (Pb) on Sargassum cymosum were evaluated by determining uptake capacity, growth rates, photosynthetic efficiency, contents of photosynthetic pigments and phenolic compounds, 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity, and morphological and cellular changes. S. cymosum was cultivated with Cu and Pb separately and combined at concentrations of 10, 25, and 50 μM for 7 days in laboratory-controlled conditions. Seaweeds under Cu treatment showed the highest biosorption capacity, and growth rates were significantly reduced compared to the control. The photosynthesis/irradiance curves showed alterations in kinetic patterns in the metal-treated samples. Specifically, Cu treatment alone inhibited electron transport rate (ETR) response, while Pb alone induced it. However, samples treated with both Cu and Pb (Cu + Pb) showed inhibition in ETR. The total amount of pigments increased relative to control. Light microscopy showed an increase in phenolic compounds, with physodes migrating towards cortical cells. Scanning electronic microscopy revealed alterations in the typical rough surface of thallus, when compared with control, especially for Pb treatments. Based on these results, it could be concluded that Cu and Pb are stress factors for S. cymosum, promoting alterations in seaweed metabolism and stimulating protective mechanisms against oxidative stress. However, the high bioaccumulation capacity of both heavy metals indicates a possible application for S. cymosum as a biosorbent agent for contaminated wastewater when metals are in low concentrations. PMID:25772683

  20. Evaluation of lead exposure in workers at secondary lead smelters in South Korea: with focus on activity of erythrocyte pyrimidine 5'-nucleotidase (P5N).

    PubMed

    Kim, Yangho; Lee, Hun; Lee, Choong Ryed; Park, Dong Uk; Yang, Jeong Sun; Park, In Jeong; Lee, Kwang Yong; Lee, MiYoung; Kim, Tae-Kyun; Sohn, Nam-Seok; Cho, Young Sook; Lee, NaRoo; Chung, Ho Keun

    2002-03-01

    To evaluate lead exposure among secondary lead-smelting workers with a focus on erythrocyte pyrimidine 5'-nucleotidase (P5N) activity, blood lead concentration (PbB), activity of P5N and other biological variables were examined in 88 exposed workers in five secondary lead smelters and in 24 non-exposed workers in Korea. All of the mean values of air lead concentration (PbA) in the three processes, scrap pretreatment, blast furnace smelting, and refining and casting of the secondary lead smelters, markedly exceeded 0.05 mg/m3. In this survey, 29 (97%) of 30 air samples for lead exceeded 0.05 mg/m3. The highest mean PbA and PbB values were found in the section of blast furnace smelting. All of the mean PbB values in all the sections were higher than 30 microg/dl. PbB of 71 (81%) of the 88 exposed workers exceeded 30 microg/dl. In 31 (35%) of the exposed workers, PbB was above 60 microg/dl. Compared with the non-exposed group, zinc protoporphyrin (ZPP) in the exposed group was significantly increased, whereas erythrocyte P5N activity and activity of erythrocyte delta-aminolevulinic acid dehydratase (ALAD) were significantly inhibited. Erythrocyte P5N activity had valid biological correlation with PbB and with other biological variables, such as ALAD activity or ZPP. Lead exposure affected hemoglobin levels via inhibition of P5N activity, as well as the heme biosynthetic pathway, in the high-exposure state. PMID:11886093

  1. MULTICOMPARTMENT KINETIC MODELS FOR LEAD. 2. LINEAR KINETICS AND VARIABLE ABSORPTION IN HUMANS WITHOUT EXCESSIVE LEAD EXPOSURES

    EPA Science Inventory

    Multicompartment models with constant fractional transfer rates have been fitted to experimental data on lead metabolism in four subjects studied by M. B. Rabinowitz, G. W. Wetherill, and J. D. Kopple (Science 182, 725-727, 1973; Environ. Health Perspect. 7, 145-153, 1974; Arch. ...

  2. Histological study on hippocampus, amygdala and cerebellum following low lead exposure during prenatal and postnatal brain development in rats.

    PubMed

    Barkur, Rajashekar Rao; Bairy, Laxminarayana K

    2016-06-01

    Neuropsychological studies in children who are exposed to lead during their early brain development have shown to develop behavioural and cognitive deficit. The aim of the present study was to assess the cellular damage in hippocampus, amygdala and cerebellum of rat pups exposed to lead during different periods of early brain development. Five groups of rat pups were investigated. (a) Control group (n = 8) (mothers of these rats were given normal drinking water throughout gestation and lactation), (b) pregestation lead-exposed group (n = 8) (mothers of these rats were exposed to 0.2% lead acetate in the drinking water for one month before conception), (c) gestation lead-exposed group (n = 8) (exposed to 0.2% lead acetate in the drinking water through the mother throughout gestation [gestation day 01 to day 21]), (d) lactation lead-exposed group (n = 8) (exposed to 0.2% lead acetate in the drinking water through the mother throughout lactation [postnatal day 01 to day 21]) and (e) gestation and lactation lead-exposed group (n = 8) (exposed to 0.2% lead acetate throughout gestation and lactation). On postnatal day 30, rat pups of all the groups were killed. Numbers of surviving neurons in the hippocampus, amygdala and cerebellum regions were counted using cresyl violet staining technique. Histological data indicate that lead exposure caused significant damage to neurons of hippocampus, amygdala and cerebellum regions in all lead-exposed groups except lactation lead-exposed group. The extent of damage to neurons of hippocampus, amygdala and cerebellum regions in lactation lead-exposed group was comparable to gestation and lactation groups even though the duration of lead exposure was much less in lactation lead-exposed group. To conclude, the postnatal period of brain development seems to be more vulnerable to lead neurotoxicity compared to prenatal period of brain development. PMID:25147304

  3. Effects of Lead Exposure and Genetic Polymorphisms on ALAD and GPx Activities in Brazilian Battery Workers.

    PubMed

    da Cunha Martins, Airton; Mazzaron Barcelos, Gustavo Rafael; Jacob Ferreira, Anna Laura Bechara; de Souza, Marilesia Ferreira; de Syllos Cólus, Ilce Mara; Antunes, Lusânia Maria Greggi; Bastos Paoliello, Monica Maria; Adeyemi, Joseph A; Barbosa, Fernando

    2015-01-01

    Lead (Pb) is a toxic metal that is widely used by metallurgical industries such as car battery recycling. Exposure to the metal may modify the redox status of the cells and consequently result in changes in activities of important enzymes such as delta-aminolevulinic acid dehydratase (ALAD) and glutathione peroxidase (GPx). Similarly, genetic polymorphisms may modulate the activities of enzymes related to detoxification processes of the metal and may modify Pb body burden. Therefore, the aims of the present study were (i) to evaluate the correlation between blood lead levels (BLL) and activities of the enzymes ALAD and GPx, and (ii) to determine whether activities of these enzymes may be influenced by polymorphisms in ALAD and GPx genes in Brazilian automotive battery workers chronically exposed to Pb, as well as the effects of these polymorphisms on BLL. Our study included 257 participants; BLL were determined by inductively couple plasma-mass spectrometry (ICP-MS), and the activities of the enzymes ALAD and GPx were quantified spectrophotometrically; and genotyping of ALAD (rs1800435) and GPx-1 (rs1800668) polymorphisms was performed by TaqMan assays (real-time polymerase chain reaction, RT-PCR). Significant negative correlations were found between BLL and ALAD activity. Subjects who carried at least one polymorphic allele for ALAD gene displayed markedly lower ALAD activities, while no significant effect was observed regarding GPx-1 polymorphism and activity of the same enzyme. Further, ALAD and GPx-1 polymorphisms exerted no marked influence on BLL. Taken together, our results showed that BLL affected ALAD but not GPx activities, and these were not modulated by polymorphisms in ALAD and GPx gene. Further, the rs1800435 SNP showed a tendency to modulate ALAD activity, while the rs1800668 SNP did not modulate GPx activity in Brazilian automotive battery workers exposed to Pb. PMID:26275098

  4. Prolonged exposure to low levels of aluminum leads to changes associated with brain aging and neurodegeneration.

    PubMed

    Bondy, Stephen C

    2014-01-01

    Aluminum is one of the most common metal elements in the earth's crust. It is not an essential element for life and has commonly been thought of as a rather inert and insoluble mineral. Therefore, it has often been regarded as not posing a significant health hazard. In consequence, aluminum-containing agents been used in many food processing steps and also in removal by flocculation of particulate organic matter from water. In recent years, acid rain has tended to mobilize aluminum-containing minerals into a more soluble form, ionic Al(3+), which has found their way into many reservoirs that constitute residential drinking water resources. As a result, the human body burden of aluminum has increased. Epidemiological studies suggest that aluminum may not be as innocuous as was previously thought and that aluminum may actively promote the onset and progression of Alzheimer's disease. Epidemiological data is strengthened by experimental evidence of aluminum exposure leading to excess inflammatory activity within the brain. Such apparently irrelevant immune activity unprovoked by an exogenous infectious agent characterizes the aging brain and is even more pronounced in several neurodegenerative diseases. The causation of most of these age-related neurological disorders is not understood but since they are generally not genetic, one must assume that their development is underlain by unknown environmental factors. There is an increasing and coherent body of evidence that implicates aluminum as being one such significant factor. Evidence is outlined supporting the concept of aluminum's involvement in hastening brain aging. This acceleration would then inevitably lead to increased incidence of specific age-related neurological diseases. PMID:24189189

  5. Long-term behavioral and electrophysiological changes associated with lead exposure at different stages of brain development in the rat.

    PubMed

    Burdette, L J; Goldstein, R

    1986-09-01

    The present investigation was conducted to assess the behavioral and electrophysiological impairments exhibited by adult male rats as a function of the developmental stage during which lead exposure occurred. Dams were given either a lead acetate (0.3%) or a control drinking solution during days 16-23 of gestation, days 1-8 or days 9-16 of nursing. The temporal and spatial activity patterns exhibited by gestationally exposed offspring in the open field between 42-45 days of age was distinguished from all other groups by the absence of a decrement in peripheral field activity across days and by increased exploration of the center field. Although open field activity proved sensitive to the timing of lead exposure, power spectral analyses of hippocampal and cortical EEG activity at 70-72 days of age revealed that lead selectively depressed 6-7 Hz energy in the hippocampus, independent of the developmental stage of exposure; cortical EEG and other hippocampal theta frequencies were unaffected. The differential sensitivity of open field activity and select hippocampal theta frequencies to the timing of lead administration suggests that the identification of toxic consequences depends on the function assessed and the developmental stage during which lead exposure occurred. PMID:3756529

  6. The protective role of ascorbic acid on hippocampal CA1 pyramidal neurons in a rat model of maternal lead exposure.

    PubMed

    Sepehri, Hamid; Ganji, Farzaneh

    2016-07-01

    Oxidative stress is a major pathogenic mechanism of lead neurotoxicity. The antioxidant ascorbic acid protects hippocampal pyramidal neurons against cell death during congenital lead exposure; however, critical functions like synaptic transmission, integration, and plasticity depend on preservation of dendritic and somal morphology. This study was designed to examine if ascorbic acid also protects neuronal morphology during developmental lead exposure. Timed pregnant rats were divided into four treatment groups: (1) control, (2) 100mg/kg ascorbic acid once a day via gavage, (3) 0.05% lead acetate in drinking water, and (4) 0.05% lead+100mg/kg oral ascorbic acid. Brains of eight male pups (P25) per treatment group were processed for Golgi staining. Changes in hippocampal CA1 pyramidal neurons' somal size were estimated by cross-sectional area and changes in dendritic arborization by Sholl's analysis. One-way ANOVA was used to compare results among treatment groups. Lead-exposed pups exhibited a significant decrease in somal size compared to controls (P<0.01) that was reversed by cotreatment with ascorbic acid. Sholl's analysis revealed a significant increase in apical dendritic branch points near cell body (P<0.05) and a decreased total dendritic length in both apical and basal dendritic trees of CA1 neurons (P<0.05). Ascorbic acid significantly but only partially reversed the somal and dendritic damage caused by developmental lead exposure. Oxidative stress thus contributes to lead neurotoxicity but other pathogenic mechanisms are also involved. PMID:26783884

  7. Lifetime exposure to environmental lead and children's intelligence at 11-13 years: the Port Pirie cohort study.

    PubMed Central

    Tong, S.; Baghurst, P.; McMichael, A.; Sawyer, M.; Mudge, J.

    1996-01-01

    OBJECTIVE--To examine the association between environmental exposure to lead and children's intelligence at age 11-13 years, and to assess the implications of exposure in the first seven years of life for later childhood development. DESIGN--Prospective cohort study. SUBJECTS--375 children born in or around the lead smelting town of Port Pirie, Australia, between 1979 and 1982. MAIN OUTCOME MEASURE--Children's intelligence quotient (IQ) measured at 11-13 years of age. RESULTS--IQ was inversely associated with both antenatal and postnatal blood lead concentrations. Verbal, performance, and full scale IQ were inversely related to blood lead concentration with no apparent threshold. Multivariate analyses indicated that after adjustment for a wide range of confounders, the postnatal blood lead concentrations (particularly within the age range 15 months to 7 years) exhibited inverse associations with IQ. Strong associations with IQ were observed for lifetime average blood lead concentrations at various ages. The expected mean full scale IQ declined by 3.0 points (95% confidence interval 0.07 to 5.93) for an increase in lifetime average blood lead concentration from 0.48 to 0.96 mumol/l (10 to 20 micrograms/dl). CONCLUSION--Exposure to environmental lead during the first seven years of life is associated with cognitive deficits that seem to persist into later childhood. PMID:8664666

  8. Stimulation of Mucin, Mucus, and Viscosity during Lubiprostone in Patients with Chronic Constipation may Potentially Lead to Increase of Lubrication

    PubMed Central

    Majewski, Marek; Sarosiek, Irene; Wallner, Grzegorz; Edlavitch, Stanley A; Sarosiek, Jerzy

    2014-01-01

    . 57.5 ml/h) (P<0.001) in basal conditions and increased by 25% (210.0 vs. 167.6 ml/h) (P=0.024) during stimulation with pentagastrin. The rate of gastric mucus secretion during therapy with lubiprostone was 91% higher (257.3 vs. 135 mg/h) (P=0.001) in basal conditions and 28% higher (348.1 vs. 270.8 mg/h) (NS) in stimulated conditions, although the latter was not statistically significant. The rate of gastric mucin secretion during lubiprostone therapy was 85% higher (98.4 vs. 65.5 mg/h) (P=0.011) in basal conditions and 38% (98.3 vs. 71.7 mg/h) (NS) higher in stimulated conditions. In basal conditions, the viscosity of gastric secretion during administration of lubiprostone increased by 240% at the lowest (P<0.001) and by 106% at the highest shear rate (P<0.001). In stimulated conditions, it increased by 226% (P<0.01) at the lowest shear rate and by 67% (P<0.01) at the highest shear rate. Conclusions: The significantly higher content of gastric mucus and mucin during therapy in basal conditions with lubiprostone in patients with CC suggests and supports the potentially leading role of lubiprostone and ClC-2 stimulation in their secretion. This increased stimulation results in profoundly increased viscosity, which in turn facilitates and/or accelerates the transit and evacuation of non-digestible food components. Although increases in mucus and mucin were observed in stimulated conditions, neither increase was statistically significant. Based on this experiment, we hypothesize that, in CC patients, the significantly increased rate of mucus and its major component, mucin secretion, during lubiprostone administration may partially explain its clinical effectiveness and also have additional clinically important effects. We propose that since the increased mucus production enhances the protective quality of the mucosal barrier, it also boosts its potential to withstand luminal aggressive components such as acid/pepsin duet, Helicobacter pylori and

  9. Lead, nickel and vanadium in seafood: an exposure assessment for Kuwaiti consumers.

    PubMed

    Bu-Olayan, A H; al-Yakoob, S

    1998-11-10

    Human exposure to lead (Pb), nickel (Ni) and vanadium (V) through the ingestion of six species of fish and two species of shrimp in Kuwait are determined. The study on seafood consumed by the Kuwaiti residents was analyzed by conducting a survey in five districts of the country, namely, Kuwait city (Capital), Farwaniya, Jahra, Hawaly and Ahmedi. Samples consisting of fish and shrimp were purchased from the local fish market during November 1995 and June 1996. Based on the survey, three major factors were investigated: (i) Pb, Ni and V concentration in the fish of locally consumed fish and shrimp; (ii) daily dietary intake of these elements in humans through consumption of seafood; and (iii) characterizing potential health risks associated with the estimated daily intakes. The risk associated with Pb, Ni and V in seafood was estimated based on a Hazard Index (HI). Although the highest HI (using the 95th percentiles of the daily intake of the element as the dose of concern) was observed for zobaidy, hamoor and shrimp, it is always < 1. This indicated that no serious health threats are associated with oil-related elements in fish and shrimp. PMID:9861729

  10. Characterization of proteome alterations in Phanerochaete chrysosporium in response to lead exposure

    PubMed Central

    2011-01-01

    Background Total soluble proteome alterations of white rot fungus Phanerochaete chrysosporium in response to different doses (25, 50 and 100 μM) of Pb (II) were characterized by 2DE in combination with MALDI-TOF-MS. Results Dose-dependent molecular response to Pb (II) involved a total of 14 up-regulated and 21 down-regulated proteins. The induction of an isoform of glyceraldehyde 3-phosphate dehydrogenase, alcohol dehydrogenase class V, mRNA splicing factor, ATP-dependent RNA helicase, thioredoxin reductase and actin required a Pb (II) dose of at least 50 μM. Analysis of the proteome dynamics of mid-exponential phase cells of P. chrysosporium subjected to 50 μM lead at exposure time intervals of 1, 2, 4 and 8 h, identified a total of 23 proteins in increased and 67 proteins in decreased amount. Overall, the newly induced/strongly up-regulated proteins involved in (i) amelioration of lipid peroxidation products, (ii) defense against oxidative damage and redox metabolism, (iii) transcription, recombination and DNA repair (iv) a yet unknown function represented by a putative protein. Conclusion The present study implicated the particular role of the elements of DNA repair, post-tanscriptional regulation and heterotrimeric G protein signaling in response to Pb (II) stress as shown for the first time for a basidiomycete. PMID:21388532

  11. Alzheimer’s Disease and Environmental Exposure to Lead: The Epidemiologic Evidence and Potential Role of Epigenetics

    PubMed Central

    Bakulski, Kelly M.; Rozek, Laura S.; Dolinoy, Dana C.; Paulson, Henry L.; Hu, Howard

    2013-01-01

    Several lines of evidence indicate that the etiology of late-onset Alzheimer’s disease (LOAD) is complex, with significant contributions from both genes and environmental factors. Recent research suggests the importance of epigenetic mechanisms in defining the relationship between environmental exposures and LOAD. In epidemiologic studies of adults, cumulative lifetime lead (Pb) exposure has been associated with accelerated declines in cognition. In addition, research in animal models suggests a causal association between Pb exposure during early life, epigenetics, and LOAD. There are multiple challenges to human epidemiologic research evaluating the relationship between epigenetics, LOAD, and Pb exposure. Epidemiologic studies are not well-suited to accommodate the long latency period between exposures during early life and onset of Alzheimer’s disease. There is also a lack of validated circulating epigenetics biomarkers and retrospective biomarkers of Pb exposure. Members of our research group have shown bone Pb is an accurate measurement of historical Pb exposure in adults, offering an avenue for future epidemiologic studies. However, this would not address the risk of LOAD attributable to early-life Pb exposures. Future studies that use a cohort design to measure both Pb exposure and validated epigenetic biomarkers of LOAD will be useful to clarify this important relationship. PMID:22272628

  12. Environmental exposure and lifestyle predictors of lead, cadmium, PCB, and DDT levels in Great Lakes fish eaters

    SciTech Connect

    Hovinga, M.E.; Sowers, M.; Humphrey, H.E. )

    1993-03-01

    A previously characterized cohort of 115 Great Lakes fish eaters and 95 non-fish-eating regional controls was reexamined in 1989. Levels of blood lead and cadmium and serum PCB and DDT were measured. Lifestyle characteristics, including recent and historic fish consumption, were evaluated as predictors of contaminant levels using multivariate regression analysis. Significantly elevated serum PCB and DDT levels were observed in fish eaters, compared with controls. Historic fish consumption, rather than recent consumption, was identified as the primary predictor of current serum levels. Mean blood lead and cadmium were also significantly higher in fish eaters than in controls. However, the primary predictors of lead and cadmium were behavioral exposures--specifically smoking and self-reported occupational and recreational exposure-rather than fish consumption. These findings illustrate the importance of evaluating a variety of possible sources when investigating human exposure to environmental contaminants.

  13. Exposure to arsenic and lead of children living near a copper-smelter in San Luis Potosi, Mexico: Importance of soil contamination for exposure of children.

    PubMed

    Carrizales, Leticia; Razo, Israel; Téllez-Hernández, Jesús I; Torres-Nerio, Rocío; Torres, Arturo; Batres, Lilia E; Cubillas, Ana-Cristina; Díaz-Barriga, Fernando

    2006-05-01

    The objective of this study was to assess the levels of soil contamination and child exposure in areas next to a primary smelter (arsenic-copper metallurgical) located in the community of Morales in San Luis Potosi, Mexico. In Morales, 90% of the soil samples studied in this work were above 400 mg/kg of lead, and above 100 mg/kg of arsenic, which are guidelines recommended by the United States Environmental Protection Agency (EPA). Bioaccessibility of these metals was studied in vitro in 10 soil samples; the median values of bioaccessibility obtained in these samples were 46.5% and 32.5% for arsenic and lead. Since the concentrations of arsenic and lead in soil were above normal values, and taking into account the bioaccessibility results, exposure to these metals was evaluated in children. Regarding lead, children aged 3-6 years had the highest mean blood lead levels; furthermore, 90% of them had concentrations above 10 microg/dl (CDC's action level). Total urinary arsenic was higher in children aged 8-9 yr; however, the percentage of children with concentrations above 50 microg/g creatinine (CDC's action level) or 100 microg/g creatinine (World Health Organization [WHO] action level) was similar among different age groups. Using the EPAs integrated exposure uptake biokinetic model for lead in children (IEUBK), we estimated that 87% of the total lead in blood is obtained from the soil/dust pathway. The exposure dose to arsenic, estimated for the children living in Morales using Monte Carlo analysis and the arsenic concentrations found in soil, was above the EPA's reference dose. With all these results, it is evident that studies are needed in order to identify adverse health effects in children living in Morales; nevertheless, it is more important to develop a risk reduction program as soon as possible. PMID:16171795

  14. Effects of Lead Exposure, Environmental Conditions, and Metapopulation Processes on Population Dynamics of Spectacled Eiders.

    USGS Publications Warehouse

    Flint, Paul L.; Grand, James B.; Petersen, Margaret; Robert Rockwell

    2016-01-01

    Spectacled eider Somateria fischeri numbers have declined and they are considered threatened in accordance with the US Endangered Species Act throughout their range. We synthesized the available information for spectacled eiders to construct deterministic, stochastic, and metapopulation models for this species that incorporated current estimates of vital rates such as nest success, adult survival, and the impact of lead poisoning on survival. Elasticities of our deterministic models suggested that the populations would respond most dramatically to changes in adult female survival and that the reductions in adult female survival related to lead poisoning were locally important. We also examined the sensitivity of the population to changes in lead exposure rates. With the knowledge that some vital rates vary with environmental conditions, we cast stochastic models that mimicked observed variation in productivity. We also used the stochastic model to examine the probability that a specific population will persist for periods of up to 50 y. Elasticity analysis of these models was consistent with that for the deterministic models, with perturbations to adult female survival having the greatest effect on population projections. When used in single population models, demographic data for some localities predicted rapid declines that were inconsistent with our observations in the field. Thus, we constructed a metapopulation model and examined the predictions for local subpopulations and the metapopulation over a wide range of dispersal rates. Using the metapopulation model, we were able to simulate the observed stability of local subpopulations as well as that of the metapopulation. Finally, we developed a global metapopulation model that simulates periodic winter habitat limitation, similar to that which might be experienced in years of heavy sea ice in the core wintering area of spectacled eiders in the central Bering Sea. Our metapopulation analyses suggested that no

  15. Lead exposure from the use of Lawsonia inermis (henna) in temporary paint-on-tattooing and hair dying.

    PubMed

    Jallad, Karim N; Espada-Jallad, Cyntia

    2008-07-01

    This study reports the evaluation of a number of spectroscopic techniques used in identifying and quantifying the presence of lead in twelve commercial and traditional henna samples. The lead levels found in henna were low with concentrations ranging from 2.29 ppm to 65.98 ppm. Henna is used as a traditional cosmetic and remedy in the Middle East, Far East, and North Africa. The very low concentrations of lead measured in these henna samples were reassuring; however, the cumulative effects of prolonged lead exposure may be of concern. Thus, the use of henna especially among children may constitute a public health risk. PMID:18407319

  16. Longitudinal changes in blood lead level in children and their relationship to season, age, and exposure to paint or plaster.

    PubMed Central

    McCusker, J

    1979-01-01

    Children screened for lead poisoning in the Brownsville district of New York City in either summer or winter were followed with blood lead tests for approximately six months to one year from screening to measure longitudinal changes in blood lead level and to identify some determinants of the changes. Only minimal evidence was found of the hypothesized summer rise in blood lead level, while the predominant trend seemed to be for blood lead levels to display statistical regression to the mean. In children found to have low to intermediate blood lead levels (less than 55 microgram/100ml) at screening, variables which were found to predict a rise in blood lead level of 10 microgram/100ml or greater from winter to summer were under age three and/or exposure to paint or plaster. PMID:426160

  17. Dose-Response Relationship between Cumulative Occupational Lead Exposure and the Associated Health Damages: A 20-Year Cohort Study of a Smelter in China

    PubMed Central

    Wu, Yue; Gu, Jun-Ming; Huang, Yun; Duan, Yan-Ying; Huang, Rui-Xue; Hu, Jian-An

    2016-01-01

    Long-term airborne lead exposure, even below official occupational limits, has been found to cause lead poisoning at higher frequencies than expected, which suggests that China’s existing occupational exposure limits should be reexamined. A retrospective cohort study was conducted on 1832 smelting workers from 1988 to 2008 in China. These were individuals who entered the plant and came into continuous contact with lead at work for longer than 3 months. The dose-response relationship between occupational cumulative lead exposure and lead poisoning, abnormal blood lead, urinary lead and erythrocyte zinc protoporphyrin (ZPP) were analyzed and the benchmark dose lower bound confidence limits (BMDLs) were calculated. Statistically significant positive correlations were found between cumulative lead dust and lead fumes exposures and workplace seniority, blood lead, urinary lead and ZPP values. A dose-response relationship was observed between cumulative lead dust or lead fumes exposure and lead poisoning (p < 0.01). The BMDLs of the cumulative occupational lead dust and fumes doses were 0.68 mg-year/m3 and 0.30 mg-year/m3 for lead poisoning, respectively. The BMDLs of workplace airborne lead concentrations associated with lead poisoning were 0.02 mg/m3 and 0.01 mg/m3 for occupational exposure lead dust and lead fume, respectively. In conclusion, BMDLs for airborne lead were lower than occupational exposure limits, suggesting that the occupational lead exposure limits need re-examination and adjustment. Occupational cumulative exposure limits (OCELs) should be established to better prevent occupational lead poisoning. PMID:26999177

  18. Dose-Response Relationship between Cumulative Occupational Lead Exposure and the Associated Health Damages: A 20-Year Cohort Study of a Smelter in China.

    PubMed

    Wu, Yue; Gu, Jun-Ming; Huang, Yun; Duan, Yan-Ying; Huang, Rui-Xue; Hu, Jian-An

    2016-03-01

    Long-term airborne lead exposure, even below official occupational limits, has been found to cause lead poisoning at higher frequencies than expected, which suggests that China's existing occupational exposure limits should be reexamined. A retrospective cohort study was conducted on 1832 smelting workers from 1988 to 2008 in China. These were individuals who entered the plant and came into continuous contact with lead at work for longer than 3 months. The dose-response relationship between occupational cumulative lead exposure and lead poisoning, abnormal blood lead, urinary lead and erythrocyte zinc protoporphyrin (ZPP) were analyzed and the benchmark dose lower bound confidence limits (BMDLs) were calculated. Statistically significant positive correlations were found between cumulative lead dust and lead fumes exposures and workplace seniority, blood lead, urinary lead and ZPP values. A dose-response relationship was observed between cumulative lead dust or lead fumes exposure and lead poisoning (p < 0.01). The BMDLs of the cumulative occupational lead dust and fumes doses were 0.68 mg-year/m³ and 0.30 mg-year/m³ for lead poisoning, respectively. The BMDLs of workplace airborne lead concentrations associated with lead poisoning were 0.02 mg/m³ and 0.01 mg/m³ for occupational exposure lead dust and lead fume, respectively. In conclusion, BMDLs for airborne lead were lower than occupational exposure limits, suggesting that the occupational lead exposure limits need re-examination and adjustment. Occupational cumulative exposure limits (OCELs) should be established to better prevent occupational lead poisoning. PMID:26999177

  19. Calculating the interindividual geometric standard deviation for use in the integrated exposure uptake biokinetic model for lead in children.

    PubMed Central

    Griffin, S; Marcus, A; Schulz, T; Walker, S

    1999-01-01

    The integrated exposure uptake biokinetic (IEUBK) model, recommended for use by the U.S. Environmental Protection Agency at residential Superfund sites to predict potential risks to children from lead exposure and to establish lead remediation levels, requires an interindividual geometric standard deviation (GSDi) as an essential input parameter. The GSDi quantifies the variability of blood lead concentrations for children exposed to similar environmental concentrations of lead. Estimates of potential risks are directly related to the GSDi, and therefore the GSDi directly impacts the scope of remediation at Superfund sites. Site-specific GSDi can be calculated for sites where blood lead and environmental lead have been measured. This paper uses data from blood and environmental lead studies conducted at the Bingham Creek and Sandy, Utah, Superfund sites to calculate GSDi using regression modeling, box modeling, and structural equation modeling. GSDis were calculated using various methods for treating values below the analytical method detection and quantitation limits. Treatment of nonquantifiable blood lead concentrations affected the GSDi more than the statistical method used to calculate the GSDi. For any given treatment, the different statistical methods produced similar GSDis. Because of the uncertainties associated with data in the blood lead studies, we recommend that a range of GSDis be used when analyzing site-specific risks associated with exposure to environmental lead instead of a single estimate. Because the different statistical methods produce similar GSDis, we recommend a simple procedure to calculate site-specific GSDi from a scientifically sound blood and environmental lead study. Images Figure 1 PMID:10339449

  20. The conjoint influence of home enriched environment and lead exposure on children's cognition and behaviour in a Mexican lead smelter community.

    PubMed

    Moodie, Sue; Ialongo, Nick; López, Patricia; Rosado, Jorge; García-Vargas, Gonzalo; Ronquillo, Dolores; Kordas, Katarzyna

    2013-01-01

    A range of studies has been conducted on the detrimental effects of lead in mining and smelting communities. The neurocognitive and behavioural health effects of lead on children are well known. This research characterized the conjoint influence of lead exposure and home enriched environment on neurocognitive function and behaviour for first-grade children living in a Mexican lead smelter community. Structural equation models were used for this analysis with latent outcome variables, Cognition and Behaviour, constructed based on a battery of assessments administered to the first-grade children, their parents, and teachers. Structural equation modelling was used to describe complex relationships of exposure and health outcomes in a manner that permitted partition of both direct and indirect effects of the factors being measured. Home Environment (a latent variable constructed from information on mother's edu