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Sample records for hair methylmercury levels

  1. Hair methylmercury levels of mummies of the Aleutian Islands, Alaska

    SciTech Connect

    Egeland, G.M. Ponce, Rafael Bloom, Nicolas S. Knecht, Rick Loring, Stephen Middaugh, John P.

    2009-04-15

    Ancient human hair specimens can shed light on the extent of pre-historic exposures to methylmercury and provide valuable comparison data with current-day exposures, particularly for Indigenous Peoples who continue to rely upon local traditional food resources. Human hair from ancient Aleutian Island Native remains were tested for total and methylmercury (Hg, MeHg) and were radiocarbon dated. The remains were approximately 500 years old (1450 A.D.). For four adults, the mean and median total hair mercury concentration was 5.8 ppm (SD=0.9). In contrast, MeHg concentrations were lower with a mean of 1.2 ppm (SD=1.8) and a median of 0.54 ppm (0.12-3.86). For the five infants, the mean and median MeHg level was 1.2 ppm (SD=1.8) and 0.20 ppm (0.007-4.61), respectively. Segmental analyses showed variations in MeHg concentrations in 1-cm segments, consistent with fluctuations in naturally occurring exposure to mercury through dietary sources. The levels are comparable to or lower than those found in fish and marine mammal-eating populations today who rely far less on subsistence food than pre-historic humans. The findings are, therefore, compatible with increased anthropogenic release of trace metals during the past several centuries.

  2. Methylmercury in hair fisherman for Turkish coasts

    SciTech Connect

    Vural, N.; Uenlue, H.

    1996-10-01

    Environmental methylmercury mainly arises from the methylation of inorganic mercury. The change in speciation of mercury from inorganic to methylated forms is the first step in the aquatic bioaccumulation processes. The bioconcentration factor of methylmercury in fish tissue to that in water is usually between 10{sup 4} and 10{sup 5}. Among seafood, fish products are the main source of methylmercury absorbed by men from the environment. Since Minimata epidemic health injuries and deaths in relation to mercury pollution, environmental and biological monitoring of inorganic and organic mercury species has gained importance through out the world and many reports have been published on the health effects and biological monitoring of mercury compounds including some Mediterranean countries. This study focuses on methylmercury in hair of fisherman living in different geographical Turkish coasts and relationship to eating fish habit. 17 refs., 1 fig., 2 tabs.

  3. Uptake of mercury by the hair of methylmercury-treated newborn mice

    SciTech Connect

    Shi, Chenyang; Lane, A.T.; Clarkson, T.W. )

    1990-04-01

    Human hair has unique advantages in monitoring environmental exposures to methyl-mercury. Using newborn Balb/c mice as a model system, the incorporation of methylmercury into the hair was studied and compared with methylmercury distributions in other tissues. Newborn mice were given intraperitoneal injections of {sup 203}Hg-labeled methylmercury at designated times according to hair growth stages of the mouse. Animals were sacrificed 2 days after dosing. Distribution of mercury in pelt and other tissues was measured. The level of mercury in pelt was found to correlate with hair growth. The amount of mercury in pelt peaked when hair growth was most rapid and the total amount of mercury in pelt was significantly higher than that in other tissues, constituting 40% of the whole body burden. However, when the hair ceased growing, the amount of mercury in pelt dramatically dropped to 4% of whole body burden and mercury concentrations in other tissues except brain were elevated. Autoradiographic studies with tritium-labeled methylmercury demonstrated that methylmercury concentrated in hair follicles in the skin. Within hair follicles and hairs, methylmercury accumulated in regions that are rich in high-sulfur proteins. The uptake of inorganic mercury (administered as HgCl{sub 2}) by pelt was also compared with that of methylmercury. The amount of inorganic mercury found in pelt was less than one-half that of methylmercury in animals with growing hair. Cessation of hair growth did not decrease the inorganic mercury level in pelt to the same extent as in the case of methylmercury.

  4. Methylmercury in fish and hair samples from the Balbina Feservoir, Brazilian Amazon.

    PubMed

    Kehrig, H A; Malm, O; Akagi, H; Guimarães, J R; Torres, J P

    1998-05-01

    The present study aimed to evaluate methylmercury in fish and human hair samples from an important hydroelectrical reservoir, Balbina (Brazil, Amazon). It presents a quite intense fishing activity and there is no known goldmining activity in its watershed. Fish and human hair were analyzed with a new extraction technique and measured by GC-ECD. Analytical quality was checked through intercomparisons between two laboratories with local samples and certified standards from IAEA. Methylmercury in hair ranged from 2.0 to 21.6 microg . g-1 with a mean of 8.76+/-5.20 microg . g-1 (N=20), while the methylmercury percentages were above 90. Fish presented methylmercury levels ranging from 0.03 to 0.9 microg small middle dot g-1 wet wt with a mean of 0.24+/-0.18 microg small middle dot g-1 wet wt (N=32), which is below the limit established for food by Brazilian legislation (0.5 microg small middle dot g-1 wet wt) and methylmercury mean percentages were above 95%. The total mean daily methylmercury intake ranged from 11 to 55 microg for 70% of the sampled population from the village based on a daily consumption of about 110 g of fish with methylmercury concentrations in the range of 0.1 to 0.5 microg . g-1. This calculation is consistent with methylmercury concentrations in hair samples in the range of 2.6 to 13.1 microg . g-1. Copyright 1998 Academic Press.

  5. Interrelationships of blood and hair mercury concentrations in a North American population exposed to methylmercury

    SciTech Connect

    Phelps, R.W.; Clarkson, T.W.

    1980-05-01

    Samples of blood and head hair were analyzed for organic and inorganic mercury from a population which consumed large amonts of fish contaminated with methylmercury. Mercury levels in newly formed hair were found to reflect those in blood with the concentration in hair being approximately 300 times that in blood. Organic and inorganic mercury levels were linearly related in both hair and blood samples, with a mean inorganic/organic ratio of 0.05 in blood and 0.21 in hair, but individual differences were found to exist. In addition, the total mercury concentration and inorganic/organic ratio in hair remained constant with time. Thus, longitudinal analysis of hair samples can provide a simple and accurate method of monitoring continuing exposure and an estimation of peak blood levels months to years after exposure.

  6. Hair mercury levels of residents in China, Indonesia, and Japan.

    PubMed

    Feng, Q; Suzuki, Y; Hisashige, A

    1998-01-01

    The authors used gold-amalgamation cold-vapor atomic absorption spectrometry and ECD-gas chromatography to analyze total mercury and methylmercury levels in hair samples obtained from 362 residents in Harbin, China; Medan, Indonesia; and Tokushima, Japan. In this study, the authors initially questioned whether mercury levels in hair differed among different study areas, and if there were differences, they questioned the contributing factors. In the three countries surveyed, total mercury and methylmercury levels in hair were lowest in residents of China and were highest in residents of Japan. In the district of Tokushima, Japan, total mercury and methylmercury levels were highest in the coastal district, followed by the middle district; the lowest levels occurred in the mountainous district. In Japan, an individual's total mercury level correlated very closely with that person's methylmercury level; in China and Indonesia, the correlation between these 2 parameters was low. No subjects in China or Indonesia had high levels of methylmercury in hair; this was true even if their total mercury levels were high. This finding suggests that the high total mercury levels observed in some residents of China and Indonesia reflected exposure to inorganic mercury. In Japan, mercury (especially methylmercury) levels in hair samples were quite high. Fish and shellfish, caught in seas uncontaminated by human activity, appeared to be major sources of the high levels of hair mercury in Japanese subjects.

  7. Public health benefits of hair-mercury analysis and dietary advice in lowering methylmercury exposure in pregnant women.

    PubMed

    Kirk, Line E; Jørgensen, Jan S; Nielsen, Flemming; Grandjean, Philippe

    2017-06-01

    To evaluate whether a public health intervention using focused dietary advice combined with a hair-mercury analysis can lower neurotoxic methylmercury exposure among pregnant women without decreasing their overall intake of seafood. A total of 146 pregnant women were consecutively recruited from the antenatal clinic at a Danish university hospital at their initial ultrasound scan. Dietary advice was provided on avoiding methylmercury exposure from large predatory fish and a hair sample from each participant was analysed for mercury, with the results being communicated shortly thereafter to the women. A dietary questionnaire was filled in. Follow-up three months later included a dietary questionnaire and a repeat hair-mercury analysis. In the follow-up group, 22% of the women had hair-mercury concentrations above a safe limit of 0.58 µg/g at enrolment, decreasing to 8% three months later. Average hair-mercury concentrations decreased by 21%. However, the total seafood intake remained at the same level after three months. Increased exposure to methylmercury among pregnant women is an important public health concern in Denmark. The observed lowering of hair-mercury concentrations associated with dietary advice corresponds to a substantial public health benefit that probably makes such an intervention highly profitable.

  8. Methylmercury levels in predatory fish species marketed in Canada.

    PubMed

    Forsyth, Don S; Casey, V; Dabeka, R W; McKenzie, A

    2004-09-01

    Mercury was detected in all analysed samples of swordfish, marlin, shark and tuna purchased from major supermarket outlets and fish retailers in three cities across Canada. Total mercury and methylmercury levels ranged up to 3845 and 2346 ng g(-1), respectively. Swordfish contained the highest levels, followed by shark, fresh/frozen tuna and marlin. Levels in canned tuna were considerably less than the other examined samples. Methylmercury was extracted with toluene from enzymatically hydrolysed samples after the addition of sulphuric acid and potassium bromide. An L-cysteine back-extraction was used to separate the methylmercury from most organic co-extractives. Analysis of methylmercury (as methylmercury bromide) was by gas chromatography with pulsed discharge detection.

  9. Neurotoxic effects of low-level methylmercury contamination in the Amazonian basin

    SciTech Connect

    Lebel, J.; Mergler, D.; Lucotte, M.; Larribe, F.; Dolbec, J.; Branches, F.; Amorim, M.

    1998-10-01

    Many studies have demonstrated mercury contamination in the Amazonian ecosystem, particularly in fish, a dietary mainstay of populations in this region. The present study focused on potential health effects of this low-level methylmercury exposure. The study was carried out in a village on the Tapajos River, a tributary of the Amazon, on 91 adults inhabitants whose hair mercury levels were inferior to 50 {micro}/g. Performance on a neurofunctional test battery and clinical manifestations of nervous system dysfunction were examined in relation to hair mercury concentrations. Near visual contrast sensitivity and manual dexterity, adjusted for age, decreased significantly with hair mercury levels (P < 0.05), while there was a tendency for muscular fatigue to increase and muscular strength to decrease in women. For the most part, clinical examinations were normal, however, hair mercury levels were significantly higher (P < 0.05) for persons who presented disorganized movements on an alternating movement task and for persons with restricted visual fields. These results suggest dose-dependent nervous system alterations at hair mercury levels below 50 {micro}g/g, previously considered a threshold for clinical effects. The profile of dysfunction in this adult population is consistent with the current knowledge on methylmercury poisoning. The long-term implications of these findings are unknown and need to be addressed.

  10. Neurotoxic effects of low-level methylmercury contamination in the Amazonian Basin.

    PubMed

    Lebel, J; Mergler, D; Branches, F; Lucotte, M; Amorim, M; Larribe, F; Dolbec, J

    1998-10-01

    Many studies have demonstrated mercury contamination in the Amazonian ecosystem, particularly in fish, a dietary mainstay of populations in this region. The present study focused on potential health effects of this low-level methylmercury exposure. The study was carried out in a village on the Tapajós River, a tributary of the Amazon, on 91 adults inhabitants (15-81 years), whose hair mercury levels were inferior to 50 mu/g. Performance on a neurofunctional test battery and clinical manifestations of nervous system dysfunction were examined in relation to hair mercury concentrations. Near visual contrast sensitivity and manual dexterity, adjusted for age, decreased significantly with hair mercury levels (P < 0.05), while there was a tendency for muscular fatigue to increase and muscular strength to decrease in women. For the most part, clinical examinations were normal, however, hair mercury levels were significantly higher (P < 0.05) for persons who presented disorganized movements on an alternating movement task and for persons with restricted visual fields. These results suggest dose-dependent nervous system alterations at hair mercury levels below 50 micrograms/g, previously considered a threshold for clinical effects. The profile of dysfunction in this adult population is consistent with the current knowledge on methyl-mercury poisoning. The long-term implications of these findings are unknown and need to be addressed.

  11. Low level methylmercury exposure affects neuropsychological function in adults

    PubMed Central

    Yokoo, Edna M; Valente, Joaquim G; Grattan, Lynn; Schmidt, Sérgio Luís; Platt, Illeane; Silbergeld, Ellen K

    2003-01-01

    Background The neurotoxic effects of methylmercury (MeHg) have been demonstrated in both human and animal studies. Both adult and fetal brains are susceptible to the effects of MeHg toxicity. However, the specific effects of adult exposures have been less well-documented than those of children with prenatal exposures. This is largely because few studies of MeHg exposures in adults have used sensitive neurological endpoints. The present study reports on the results of neuropsychological testing and hair mercury concentrations in adults (>17 yrs) living in fishing communities of Baixada Cuiabana (Mato Grosso) in the Pantanal region of Brazil. Methods A cross-sectional study was conducted in six villages on the Cuiaba River. Participants included 129 men and women older than 17 years of age. They were randomly selected in proportion to the age range and number of inhabitants in each village. Questionnaire information was collected on demographic variables, including education, occupation, and residence history. Mercury exposure was determined by analysis of hair using flameless atomic absorption spectrophotometry. The neurocognitive screening battery included tests from the Wechsler Memory Scale and the Wechsler Adult Intelligence Scale, Concentrated Attention Test of the Toulouse-Pierron Factorial Battery, the Manual Ability Subtests of the Tests of Mechanical Ability, and the Profile of Mood States. Results Mercury exposures in this population were associated with fish consumption. The hair mercury concentration in the 129 subjects ranged from 0.56 to 13.6 μg/g; the mean concentration was 4.2 ± 2.4 micrograms/g and the median was 3.7 μg/g. Hair mercury levels were associated with detectable alterations in performance on tests of fine motor speed and dexterity, and concentration. Some aspects of verbal learning and memory were also disrupted by mercury exposure. The magnitude of the effects increased with hair mercury concentration, consistent with a dose

  12. Hollow fiber liquid phase microextraction combined with graphite furnace atomic absorption spectrometry for the determination of methylmercury in human hair and sludge samples

    NASA Astrophysics Data System (ADS)

    Jiang, Hongmei; Hu, Bin; Chen, Beibei; Zu, Wanqing

    2008-07-01

    Two methods, based on hollow fiber liquid-liquid-liquid (three phase) microextraction (HF-LLLME) and hollow fiber liquid phase (two phase) microextraction (HF-LPME), have been developed and critically compared for the determination of methylmercury content in human hair and sludge by graphite furnace atomic absorption spectrometry (GFAAS). In HF-LPME, methylmercury was extracted into the organic phase (toluene) prior to its determination by GFAAS, while inorganic mercury remained as a free species in the sample solution. In HF-LLLME, methylmercury was first extracted into the organic phase (toluene) and then into the acceptor phase (4% thiourea in 1 mol L - 1 HCl) prior to its determination by GFAAS, while inorganic mercury remained in the sample solution. The total mercury was determined by inductively coupled plasma-mass spectrometry (ICP-MS), and the levels of inorganic mercury in both HF-LLLME and HF-LPME were obtained by subtracting methylmercury from total mercury. The factors affecting the microextraction of methylmercury, including organic solvent, extraction time, stirring rate and ionic strength, were investigated and the optimal extraction conditions were established for both HF-LLLPME and HF-LPME. With a consumption of 3.0 mL of the sample solution, the enrichment factors were 204 and 55 for HF-LLLPME and HF-LPME, respectively. The limits of detection (LODs) for methylmercury were 0.1 μg L - 1 and 0.4 μg L - 1 (as Hg) with precisions (RSDs (%), c = 5 μg L - 1 (as Hg), n = 5) of 13% and 11% for HF-LLLPME-GFAAS and HF-LPME-GFAAS, respectively. For ICP-MS determination of total mercury, a limit of detection of 39 ng L - 1 was obtained. Finally, HF-LLLME-GFAAS was applied to the determination of methylmercury content in human hair and sludge, and the recoveries for the spiked samples were in the range of 99-113%. In order to validate the method, HF-LLLME-GFAAS was also applied to the analysis of a certified reference material of NRCC DORM-2 dogfish

  13. Biological variables in the hair uptake of methylmercury from blood in the Macaque monkey

    SciTech Connect

    Mottet, N.K.; Body, R.L.; Wilkens, V.; Burbacher, T.M.

    1987-04-01

    The total mercury (Hg) in hair and blood of 45 young healthy adult female Macaque fascicularis given 0, 50, 70, or 90 ..mu..g MeHg/kg body wt orally in apple juice daily revealed a close and constant ratio between blood Hg and hair. The amount of hair Hg does not increase with time (maximum period of observation 490 days) at a given dose level. Also the ratio was unchanged between background and subtoxic dose levels. Individuals at a given dose level with a higher-than-average blood level had a proportionately higher hair level. The Macaque blood/hair ratio is markedly lower than that reported for humans. Pregnancy did not have an appreciable effect on the hair mercury level. Review of the known variables in human and Macaque hair growth and structures does not provide an explanation for the difference. They suggest that an as yet unidentified biological variable(s), possibly circumfollicular blood flow, could account for the difference. This ratio difference notwithstanding, controlled studies on Macaque hair such as this add support for the validity of terminal hair as a trace metal exposure indicator.

  14. Changes in mercury concentrations of segmental maternal hair during gestation and their correlations with other biomarkers of fetal exposure to methylmercury in the Japanese population.

    PubMed

    Sakamoto, Mineshi; Kubota, Machi; Murata, Katsuyuki; Nakai, Kunihiko; Sonoda, Ikuko; Satoh, Hiroshi

    2008-02-01

    Methylmercury (MeHg) is one of the most hazardous substances that affects the fetus through fish consumption. The objective of this study was to evaluate the changes in the level of exposure to MeHg by assessing the mercury (Hg) concentrations of the segmental hair at parturition and 3 months after parturition, and to study their correlations with the total Hg concentrations of maternal and cord red blood cells (RBCs) and neonatal hair as biomarkers of fetal exposure to MeHg at parturition. In total, 40 paired samples of maternal hair from the scalp, maternal and cord RBCs, and 21 samples of neonatal hair from the scalp were collected at parturition. In addition, 19 samples of maternal hair from the scalp were collected at 3 months after parturition. The maternal hair samples were cut into 1cm segments from the scalp end toward the tip. The geometric mean of the Hg concentrations in cord RBCs was approximately 1.6 times higher than that in the maternal RBCs, and a strong correlation coefficient (r=0.91) was found between them. The increase or decrease in the Hg concentrations of the segmental hair during gestation differed largely among individuals. The correlation coefficients between the Hg concentrations of the segmental hair and cord RBCs were the strongest (r=0.90) in the hair segment 1cm from the scalp and decreased gradually with the distance from the scalp. The correlation coefficients between the Hg concentrations of the segmental hair collected at 3 months after parturition and maternal RBCs were over 0.9 in the hair segments 5 and 6 cm from the scalp, suggesting that the time required for the incorporation of Hg from the blood into a growing hair was very short. The geometric mean of Hg concentrations in the neonatal hair at parturition was similar to that in the maternal hair 1cm from the scalp at parturition, and they exhibited a strong correlation (r=0.95). The findings of this study indicate that maternal hair close to the scalp at parturition and

  15. Hair mercury levels in relation to fish consumption in a community of the Moroccan Mediterranean coast.

    PubMed

    Elhamri, Hecham; Idrissi, Larbi; Coquery, Marina; Azemard, Sabine; El Abidi, Abdellah; Benlemlih, Mohamed; Saghi, Mohamed; Cubadda, Francesco

    2007-11-01

    Coastal populations with high seafood consumption in the Mediterranean have a significant exposure to dietary methylmercury, and areas where environmental mercury pollution is an issue due to industrial activities are of special concern. The study was undertaken with the aim of assessing methylmercury exposure through fish consumption in a community of north Morocco and characterizing the relevant health risk. Concentrations of total mercury were determined in human hair, a biomarker of methylmercury exposure, and in locally consumed fish by cold vapour atomic absorption spectrophotometry. Based on consumption frequencies reported by the 108 subjects included in the study the weekly intake of methylmercury was estimated and biomarker data were evaluated in relation to the estimated intake and the sociodemographic characteristics of the population. Multiple regression analysis was employed for the interpretation of hair mercury data in relation to fish consumption frequency, gender and the age of individuals. Mercury concentrations in hair ranged from 0.22 to 9.56 microg g(-1) (geometric mean = 1.79 microg g(-1)) and were closely related to fish intake. Fisherman and their families consumed fish three to five times per week and were the most exposed population subgroup. A high proportion of women of child-bearing age (50%) had relatively high levels of mercury in their hair (3.08-7.88 microg g(-1)).

  16. Mercury speciation in hair by headspace injection-gas chromatography-atomic fluorescence spectrometry (methylmercury) and combustion-atomic absorption spectrometry (total Hg).

    PubMed

    Gao, Y; De Galan, S; De Brauwere, A; Baeyens, W; Leermakers, M

    2010-10-15

    The speciation of Hg in human hair was carried out with combustion-atomic absorption spectrometry for total Hg (THg) and headspace-gas chromatography-atomic fluorescence spectrometry (HS-GC-AFS) for methylmercury (MMHg). The determination of total Hg in hair was carried out with the AMA analyzer (Advanced Mercury Analyser 254). Accuracy and reproducibility were assessed on a Certified Reference hair sample (IAEA-086 CRM), yielding, respectively, a recovery of 97.5% and a RSD of 3.2%. Analyses of 10 blank measurements resulted in a detection limit of 1.5 ng g(-1) of THg for a 20mg sample of human hair. MMHg concentrations in hair were assessed with HS-GC-AFS in a single analysis step. Either acid or alkaline extraction can be applied because they yielded very similar results on a IAEA-086 CRM: we observed a recovery of 103% and a RSD of 7% with acid extraction and a recovery of 110% and a RSD of 9% with alkaline extraction. Optimization of the headspace vial, injection and GC parameters is described. The detection limit of the MMHg determination in human hair, which amounts to 0.04 ng g(-1) for a 20mg sample, is far below the concentrations observed in natural samples. The number of samples that can be analyzed per hour, respectively, amounts to 8 for THg and 4 for MMHg. Finally, Hg speciation in natural human hair samples was carried out by combining both AMA and HS-GC-AFS analysis methods. THg levels were at the μg g(-1), level, with an average MMHg fraction of about 70%.

  17. Hair mercury levels in Amazonian populations: spatial distribution and trends

    PubMed Central

    2009-01-01

    Background Mercury is present in the Amazonian aquatic environments from both natural and anthropogenic sources. As a consequence, many riverside populations are exposed to methylmercury, a highly toxic organic form of mercury, because of their intense fish consumption. Many studies have analysed this exposure from different approaches since the early nineties. This review aims to systematize the information in spatial distribution, comparing hair mercury levels by studied population and Amazonian river basin, looking for exposure trends. Methods The reviewed papers were selected from scientific databases and online libraries. We included studies with a direct measure of hair mercury concentrations in a sample size larger than 10 people, without considering the objectives, approach of the study or mercury speciation. The results are presented in tables and maps by river basin, displaying hair mercury levels and specifying the studied population and health impact, if any. Results The majority of the studies have been carried out in communities from the central Amazonian regions, particularly on the Tapajós River basin. The results seem quite variable; hair mercury means range from 1.1 to 34.2 μg/g. Most studies did not show any significant difference in hair mercury levels by gender or age. Overall, authors emphasized fish consumption frequency as the main risk factor of exposure. The most studied adverse health effect is by far the neurological performance, especially motricity. However, it is not possible to conclude on the relation between hair mercury levels and health impact in the Amazonian situation because of the relatively small number of studies. Conclusions Hair mercury levels in the Amazonian regions seem to be very heterogenic, depending on several factors. There is no obvious spatial trend and there are many areas that have never been studied. Taking into account the low mercury levels currently handled as acceptable, the majority of the Amazonian

  18. Sulfate threshold target to control methylmercury levels in wetland ecosystems

    USGS Publications Warehouse

    Corrales, J.; Naja, G.M.; Dziuba, C.; Rivero, R.G.; Orem, W.

    2011-01-01

    Sulfate contamination has a significant environmental implication through the stimulation of toxic hydrogen sulfide and methylmercury (MeHg) production. High levels of MeHg are a serious problem in many wetland ecosystems worldwide. In the Florida Everglades, it has been demonstrated that increasing MeHg occurrence is due to a sulfate contamination problem. A promising strategy of lowering the MeHg occurrence is to reduce the amount of sulfate entering the ecosystem. High surface water sulfate concentrations in the Everglades are mainly due to discharges from the Everglades Agricultural Area (EAA) canals. Water and total sulfur mass balances indicated that total sulfur released by soil oxidation, Lake Okeechobee and agricultural application were the major sources contributing 49,169, 35,217 and 11,775mtonsyear-1, respectively. Total sulfur loads from groundwater, levees, and atmospheric deposition contributed to a lesser extent: 4055; 5858 and 4229mtonsyear-1, respectively. Total sulfur leaving the EAA into Water Conservation Areas (WCAs) through canal discharge was estimated at 116,360mtonsyear-1, and total sulfur removed by sugarcane harvest accounted for 23,182mtonsyear-1. Furthermore, a rise in the mineral content and pH of the EAA soil over time, suggested that the current rates of sulfur application would increase as the buffer capacity of the soil increases. Therefore, a site specific numeric criterion for sulfate of 1mgL-1 was recommended for the protection of the Everglades; above this level, mercury methylation is enhanced. In parallel, sulfide concentrations in the EAA exceeded the 2??gL-1 criterion for surface water already established by the U.S. Environmental Protection Agency (EPA). ?? 2011 Elsevier B.V.

  19. Sulfate threshold target to control methylmercury levels in wetland ecosystems.

    PubMed

    Corrales, Juliana; Naja, Ghinwa M; Dziuba, Catherine; Rivero, Rosanna G; Orem, William

    2011-05-01

    Sulfate contamination has a significant environmental implication through the stimulation of toxic hydrogen sulfide and methylmercury (MeHg) production. High levels of MeHg are a serious problem in many wetland ecosystems worldwide. In the Florida Everglades, it has been demonstrated that increasing MeHg occurrence is due to a sulfate contamination problem. A promising strategy of lowering the MeHg occurrence is to reduce the amount of sulfate entering the ecosystem. High surface water sulfate concentrations in the Everglades are mainly due to discharges from the Everglades Agricultural Area (EAA) canals. Water and total sulfur mass balances indicated that total sulfur released by soil oxidation, Lake Okeechobee and agricultural application were the major sources contributing 49,169, 35,217 and 11,775mtonsyear(-1), respectively. Total sulfur loads from groundwater, levees, and atmospheric deposition contributed to a lesser extent: 4055; 5858 and 4229mtonsyear(-1), respectively. Total sulfur leaving the EAA into Water Conservation Areas (WCAs) through canal discharge was estimated at 116,360mtonsyear(-1), and total sulfur removed by sugarcane harvest accounted for 23,182mtonsyear(-1). Furthermore, a rise in the mineral content and pH of the EAA soil over time, suggested that the current rates of sulfur application would increase as the buffer capacity of the soil increases. Therefore, a site specific numeric criterion for sulfate of 1mgL(-1) was recommended for the protection of the Everglades; above this level, mercury methylation is enhanced. In parallel, sulfide concentrations in the EAA exceeded the 2μgL(-1) criterion for surface water already established by the U.S. Environmental Protection Agency (EPA). Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Implications of mercury concentrations in umbilical cord tissue in relation to maternal hair segments as biomarkers for prenatal exposure to methylmercury.

    PubMed

    Sakamoto, Mineshi; Murata, Katsuyuki; Domingo, José L; Yamamoto, Megumi; Oliveira, Ricardo B; Kawakami, Shoichi; Nakamura, Masaaki

    2016-08-01

    In this study, we investigated how mercury (Hg) concentrations in umbilical cord tissue are correlated with those in biomarkers for prenatal exposure to methylmercury (MeHg). Total Hg (T-Hg) concentrations were measured in 54 mother-child paired samples of maternal blood, umbilical cord tissue, cord blood, and maternal hair segments (1-cm incremental segments from the scalp) collected at parturition. MeHg concentrations were also measured in the cord tissue. Median T-Hg and MeHg concentrations in cord tissue on a dry-weight basis (d.w.) were 62.2ng/g and 56.7ng/g, respectively. Proportions of MeHg to T-Hg were approximately 95%. Both T-Hg and MeHg in cord tissue (d.w.) showed better correlations with T-Hg in cord blood than did T-Hg in cord tissue on a wet-weight basis (w.w.). Median T-Hg concentrations in maternal blood, cord blood, and maternal hair (0-1cm from the scalp) were 3.79ng/g, 7.26ng/g, and 1.35 μg/g, respectively. Median T-Hg concentration in cord blood was 1.92 times higher than that in maternal blood. T-Hg in cord tissue (d.w.) showed a strong correlation with that in cord blood (r=0.912, p<0.01). Among the hair segments, T-Hg in cord tissue (d.w.) showed the strongest correlation (r=0.854, p<0.01) with that in maternal hair at 0-1cm from the scalp, reflecting growth for approximately 1 month before parturition. Based on the present results, T-Hg and MeHg concentrations in cord tissue may be useful biomarkers for prenatal MeHg exposure of the fetus, especially reflecting the maternal MeHg body burden during late gestation. The conversion factors for T-Hg and MeHg concentrations in cord tissue (d.w.) to T-Hg concentrations in maternal hair (0-1cm from the scalp) were calculated to be 22.37 and 24.09, respectively. This information will be useful for evaluating maternal MeHg exposure levels in retrospective studies using preserved umbilical cord tissue. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Freshwater discharges drive high levels of methylmercury in Arctic marine biota

    PubMed Central

    Schartup, Amina T.; Balcom, Prentiss H.; Soerensen, Anne L.; Gosnell, Kathleen J.; Calder, Ryan S. D.; Mason, Robert P.; Sunderland, Elsie M.

    2015-01-01

    Elevated levels of neurotoxic methylmercury in Arctic food-webs pose health risks for indigenous populations that consume large quantities of marine mammals and fish. Estuaries provide critical hunting and fishing territory for these populations, and, until recently, benthic sediment was thought to be the main methylmercury source for coastal fish. New hydroelectric developments are being proposed in many northern ecosystems, and the ecological impacts of this industry relative to accelerating climate changes are poorly characterized. Here we evaluate the competing impacts of climate-driven changes in northern ecosystems and reservoir flooding on methylmercury production and bioaccumulation through a case study of a stratified sub-Arctic estuarine fjord in Labrador, Canada. Methylmercury bioaccumulation in zooplankton is higher than in midlatitude ecosystems. Direct measurements and modeling show that currently the largest methylmercury source is production in oxic surface seawater. Water-column methylation is highest in stratified surface waters near the river mouth because of the stimulating effects of terrestrial organic matter on methylating microbes. We attribute enhanced biomagnification in plankton to a thin layer of marine snow widely observed in stratified systems that concentrates microbial methylation and multiple trophic levels of zooplankton in a vertically restricted zone. Large freshwater inputs and the extensive Arctic Ocean continental shelf mean these processes are likely widespread and will be enhanced by future increases in water-column stratification, exacerbating high biological methylmercury concentrations. Soil flooding experiments indicate that near-term changes expected from reservoir creation will increase methylmercury inputs to the estuary by 25–200%, overwhelming climate-driven changes over the next decade. PMID:26351688

  2. Freshwater discharges drive high levels of methylmercury in Arctic marine biota.

    PubMed

    Schartup, Amina T; Balcom, Prentiss H; Soerensen, Anne L; Gosnell, Kathleen J; Calder, Ryan S D; Mason, Robert P; Sunderland, Elsie M

    2015-09-22

    Elevated levels of neurotoxic methylmercury in Arctic food-webs pose health risks for indigenous populations that consume large quantities of marine mammals and fish. Estuaries provide critical hunting and fishing territory for these populations, and, until recently, benthic sediment was thought to be the main methylmercury source for coastal fish. New hydroelectric developments are being proposed in many northern ecosystems, and the ecological impacts of this industry relative to accelerating climate changes are poorly characterized. Here we evaluate the competing impacts of climate-driven changes in northern ecosystems and reservoir flooding on methylmercury production and bioaccumulation through a case study of a stratified sub-Arctic estuarine fjord in Labrador, Canada. Methylmercury bioaccumulation in zooplankton is higher than in midlatitude ecosystems. Direct measurements and modeling show that currently the largest methylmercury source is production in oxic surface seawater. Water-column methylation is highest in stratified surface waters near the river mouth because of the stimulating effects of terrestrial organic matter on methylating microbes. We attribute enhanced biomagnification in plankton to a thin layer of marine snow widely observed in stratified systems that concentrates microbial methylation and multiple trophic levels of zooplankton in a vertically restricted zone. Large freshwater inputs and the extensive Arctic Ocean continental shelf mean these processes are likely widespread and will be enhanced by future increases in water-column stratification, exacerbating high biological methylmercury concentrations. Soil flooding experiments indicate that near-term changes expected from reservoir creation will increase methylmercury inputs to the estuary by 25-200%, overwhelming climate-driven changes over the next decade.

  3. Reservoir stratification affects methylmercury levels in river water, plankton, and fish downstream from Balbina hydroelectric dam, Amazonas, Brazil.

    PubMed

    Kasper, Daniele; Forsberg, Bruce R; Amaral, João H F; Leitão, Rafael P; Py-Daniel, Sarah S; Bastos, Wanderley R; Malm, Olaf

    2014-01-21

    The river downstream from a dam can be more contaminated by mercury than the reservoir itself. However, it is not clear how far the contamination occurs downstream. We investigated the seasonal variation of methylmercury levels in the Balbina reservoir and how they correlated with the levels encountered downstream from the dam. Water, plankton, and fishes were collected upstream and at sites between 0.5 and 250 km downstream from the dam during four expeditions in 2011 and 2012. Variations in thermal stratification of the reservoir influenced the methylmercury levels in the reservoir and in the river downstream. Uniform depth distributions of methylmercury and oxygen encountered in the poorly stratified reservoir during the rainy season collections coincided with uniformly low methylmercury levels along the river downstream from the dam. During dry season collections, the reservoir was strongly stratified, and anoxic hypolimnion water with high methylmercury levels was exported downstream. Methylmercury levels declined gradually to 200 km downstream. In general, the methylmercury levels in plankton and fishes downstream from the dam were higher than those upstream. Higher methylmercury levels observed 200-250 km downstream from the dam during flooding season campaigns may reflect the greater inflow from tributaries and flooding of natural wetlands that occurred at this time.

  4. Influence of Methylmercury from Tributary Streams on Mercury Levels in Savannah River Asiatic Clams

    SciTech Connect

    Paller, M.H.

    2004-03-01

    Average methylmercury levels in five Savannah River tributary streams sampled 11 times over two years were nearly twice as high as in the Savannah River. Total mercury levels in the tributaries did not differ significantly from the river. All of the tributaries drained extensive wetlands that would be expected to support comparatively high rates of methylation. Mercury concentrations in Asiatic clams (Corbicula fluminea) collected from the discharge plumes of Savannah River tributaries were significantly higher than in Asiatic clams collected from the Savannah River upstream from the tributary mouths . These results indicate that streams draining wetlands into coastal plain rivers can create localized areas of elevated methylmercury with resulting increases in the mercury levels of river biota.

  5. Evaluating the potential efficacy of mercury total maximum daily loads on aqueous methylmercury levels in four coastal watersheds.

    PubMed

    Rothenberg, Sarah E; Ambrose, Richard F; Jay, Jennifer A

    2008-08-01

    Of the approximately 780 U.S. EPA approved mercury total maximum daily loads (TMDLs), most specify a reduction in total mercury (Hg(T)) loads to reduce methylmercury levels in fish tissue, assuming a 1:1 correspondence. However, mercury methylation is more complex, and therefore, proposed load reductions may not be adequate. Using multiple regression with microlevel and macrolevel variables, the potential efficacy of mercury TMDLs on decreasing aqueous methylmercury levels was investigated in four coastal watersheds: Mugu Lagoon (CA), San Francisco Bay Estuary, Long Island Sound, and south Florida. Hg(T) and methylmercury levels were positively correlated in all watersheds except in Long Island Sound, where spatial differences explained over 40% of the variability in methylmercury levels. A mercury TMDL would be least effective in Long Island Sound due to spatial heterogeneity but most effective in south Florida, where the ratio between aqueous Hg(T) and methylmercury levels was close to 1 and the 95% confidence interval was narrow, indicating a probable reduction in aqueous methylmercury levels if Hg(T) loads were reduced.

  6. Methylmercury in fish: a review of residue levels, fish consumption and regulatory action in the United States

    SciTech Connect

    Tollefson, L.; Cordle, F.

    1986-09-01

    The dangers associated with the consumption of large amounts of methylmercury in fish are well recognized, and there is some evidence to suggest that methylmercury may be the cause of subtle neurological impairments when ingested at even low to moderate levels, particularly the prenatal and early childhood periods. This concern has prompted a continuing assessment of the risk of methylmercury toxicity among fish consumers in the US as well as other countries. The toxicokinetics of methylmercury in humans are reviewed and used to estimate body burdens associated with toxic effects. To determine seafood consumption patterns among the continental US population the Food and Drug Administration (FDA) has analyzed data from a diary study commissioned by the Tuna Research Foundation. Mercury residue levels in domestic fish sampled by the FDA were used to determine the level of exposure to methylmercury. Until evidence is presented that substantially lowers the known body burden of methylmercury which causes toxicity, calculations indicate that the current 1.0 ppm regulatory level provides adequate protection for the average fish consumer, for young children, and for a significant number of consumers exceeding the acceptable daily intake. However, additional studies are being carried out in a continuing process to ensure that safe levels of prenatal exposure to mercury residues in fish are maintained.

  7. Hair Nicotine Levels in Children With Bronchopulmonary Dysplasia

    PubMed Central

    Aherrera, Angela D.; Breysse, Patrick N.; Winickoff, Jonathan P.; Klein, Jonathan D.; McGrath-Morrow, Sharon A.

    2015-01-01

    BACKGROUND: Tobacco smoke exposure (TSE) may increase respiratory morbidities in young children with bronchopulmonary dysplasia (BPD). Rapid respiratory rates, close proximity to a smoking caregiver, and increased dermal absorption of tobacco smoke components can contribute to systemic exposure. In this study, hair nicotine levels were used as a biomarker of chronic TSE in young children with BPD to determine if hair nicotine levels correlate with caregiver self-report of TSE and respiratory morbidities. METHODS: From 2012 to 2014, hair nicotine levels were measured from consecutive children seen in a BPD outpatient clinic and compared with caregiver questionnaires on household smoking. The relationship between respiratory morbidities and self-reported TSE or hair nicotine level was assessed. RESULTS: The mean hair nicotine level from 117 children was 3.1 ± 13.2 ng/mg. Hair nicotine levels were significantly higher in children from smoking households by caregiver self-report compared with caregivers who reported no smoking (8.2 ± 19.7 ng/mg vs 1.8 ± 10.7; P < .001). In households that reported smoking, hair nicotine levels were higher in children with a primary caregiver who smoked compared with a primary caregiver who did not smoke. Among children with BPD who required respiratory support (n = 50), a significant association was found between higher log hair nicotine levels and increased hospitalizations and limitation of activity. CONCLUSIONS: Chronic TSE is common in children with BPD, with hair nicotine levels being more likely to detect TSE than caregiver self-report. Hair nicotine levels were also a better predictor of hospitalization and activity limitation in children with BPD who required respiratory support at outpatient presentation. PMID:25647675

  8. Environmental influence on trace element levels in human hair

    SciTech Connect

    Limic, N.; Valkovic, V.

    1986-12-01

    Trace element content of human hair depends on many factors. It has been shown by a large number of investigators that environmental factors play an important role. Elements from air particulates, water, shampoo or other media get incorporated into the hair structure. Here a model is proposed in which different contributions to trace element levels in human hair are factorized and the environmental contribution to the radial and longitudinal concentration profiles can be calculated. With the proper understanding of environmental contamination, hair analysis has better chances of being used as a diagnostic tool.

  9. Serum Biotin Levels in Women Complaining of Hair Loss.

    PubMed

    Trüeb, Ralph M

    2016-01-01

    Biotin is a coenzyme for carboxylase enzymes that assist various metabolic reactions involved in fatty acid synthesis, branched-chain amino acid catabolism, and gluconeogenesis important for maintenance of healthy skin and hair. Due to its availability, affordability, and effective marketing for this purpose, biotin is a popular nutritional supplement for treatment of hair loss. However, there are little data on the frequency of biotin deficiency in patients complaining of hair loss and on the value of oral biotin for treatment of hair loss that is not due to an inborn error of biotin metabolism or deficiency. The aim of this study was to determine the frequency and significance of biotin deficiency in women complaining of hair loss. Biotin deficiency was found in 38% of women complaining of hair loss. Of those showing diffuse telogen effluvium in trichograms (24%), 35% had evidence of associated seborrheic-like dermatitis. About 11% of patients with biotin deficiency had a positive personal history for risk factors for biotin deficiency. The custom of treating women complaining of hair loss in an indiscriminate manner with oral biotin supplementation is to be rejected, unless biotin deficiency and its significance for the complaint of hair loss in an individual has been demonstrated on the basis of a careful patient history, clinical examination, determination of serum biotin levels, and exclusion of alternative factors responsible for hair loss.

  10. Serum Biotin Levels in Women Complaining of Hair Loss

    PubMed Central

    Trüeb, Ralph M

    2016-01-01

    Biotin is a coenzyme for carboxylase enzymes that assist various metabolic reactions involved in fatty acid synthesis, branched-chain amino acid catabolism, and gluconeogenesis important for maintenance of healthy skin and hair. Due to its availability, affordability, and effective marketing for this purpose, biotin is a popular nutritional supplement for treatment of hair loss. However, there are little data on the frequency of biotin deficiency in patients complaining of hair loss and on the value of oral biotin for treatment of hair loss that is not due to an inborn error of biotin metabolism or deficiency. The aim of this study was to determine the frequency and significance of biotin deficiency in women complaining of hair loss. Biotin deficiency was found in 38% of women complaining of hair loss. Of those showing diffuse telogen effluvium in trichograms (24%), 35% had evidence of associated seborrheic-like dermatitis. About 11% of patients with biotin deficiency had a positive personal history for risk factors for biotin deficiency. The custom of treating women complaining of hair loss in an indiscriminate manner with oral biotin supplementation is to be rejected, unless biotin deficiency and its significance for the complaint of hair loss in an individual has been demonstrated on the basis of a careful patient history, clinical examination, determination of serum biotin levels, and exclusion of alternative factors responsible for hair loss. PMID:27601860

  11. Chronic atrophic gastritis in association with hair mercury level.

    PubMed

    Xue, Zeyun; Xue, Huiping; Jiang, Jianlan; Lin, Bing; Zeng, Si; Huang, Xiaoyun; An, Jianfu

    2014-11-01

    The objective of this study was to explore hair mercury level in association with chronic atrophic gastritis, a precancerous stage of gastric cancer (GC), and thus provide a brand new angle of view on the timely intervention of precancerous stage of GC. We recruited 149 healthy volunteers as controls and 152 patients suffering from chronic gastritis as cases. The controls denied upper gastrointestinal discomforts, and the cases were diagnosed as chronic superficial gastritis (n=68) or chronic atrophic gastritis (n=84). We utilized Mercury Automated Analyzer (NIC MA-3000) to detect hair mercury level of both healthy controls and cases of chronic gastritis. The statistic of measurement data was expressed as mean ± standard deviation, which was analyzed using Levene variance equality test and t test. Pearson correlation analysis was employed to determine associated factors affecting hair mercury levels, and multiple stepwise regression analysis was performed to deduce regression equations. Statistical significance is considered if p value is less than 0.05. The overall hair mercury level was 0.908949 ± 0.8844490 ng/g [mean ± standard deviation (SD)] in gastritis cases and 0.460198 ± 0.2712187 ng/g (mean±SD) in healthy controls; the former level was significantly higher than the latter one (p=0.000<0.01). The hair mercury level in chronic atrophic gastritis subgroup was 1.155220 ± 0.9470246 ng/g (mean ± SD) and that in chronic superficial gastritis subgroup was 0.604732 ± 0.6942509 ng/g (mean ± SD); the former level was significantly higher than the latter level (p<0.01). The hair mercury level in chronic superficial gastritis cases was significantly higher than that in healthy controls (p<0.05). The hair mercury level in chronic atrophic gastritis cases was significantly higher than that in healthy controls (p<0.01). Stratified analysis indicated that the hair mercury level in healthy controls with eating seafood was significantly higher than that in healthy

  12. Trace-elements, methylmercury and metallothionein levels in Magellanic penguin (Spheniscus magellanicus) found stranded on the Southern Brazilian coast.

    PubMed

    Kehrig, Helena A; Hauser-Davis, Rachel A; Seixas, Tércia G; Fillmann, Gilberto

    2015-07-15

    Magellanic penguins have been reported as good biomonitors for several types of pollutants, including trace-elements. In this context, selenium (Se), total mercury, methylmercury, inorganic mercury (Hg(inorg)), cadmium (Cd) and lead (Pb), as well as metallothionein (MT) levels, were evaluated in the feathers, liver and kidney of juvenile Magellanic penguins found stranded along the coast of Southern Brazil. The highest concentrations of all trace-elements and methylmercury were found in internal organs. Concentrations of Cd and Se in feathers were extremely low in comparison with their concentrations in soft tissues. The results showed that both Se and MT are involved in the detoxification of trace-elements (Cd, Pb and Hg(inorg)) since statistically significant relationships were found in liver. Conversely, hepatic Se was shown to be the only detoxifying agent for methylmercury. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Methylmercury Exposure and Health Effects

    PubMed Central

    Hong, Young-Seoub; Kim, Yu-Mi

    2012-01-01

    Methylmercury is a hazardous substance that is of interest with regard to environmental health, as inorganic mercury circulating in the general environment is dissolved into freshwater and seawater, condensed through the food chain, ingested by humans, and consequently affects human health. Recently, there has been much interest and discussion regarding the toxicity of methylmercury, the correlation with fish and shellfish intake, and methods of long-term management of the human health effects of methylmercury. What effects chronic exposure to a low concentration of methylmercury has on human health remains controversial. Although the possibility of methylmercury poisoning the heart and blood vessel system, the reproductive system, and the immune system is continuously raised and discussed, and the carcinogenicity of methylmercury is also under discussion, a clear conclusion regarding the human health effects according to exposure level has not yet been drawn. The Joint FAO/WHO Expert Committee on Food Additives proposed to prepare additional fish and shellfish intake recommendations for consumers based on the quantified evaluation of the hazardousness of methylmercury contained in fish and shellfish, methylmercury management in the Korea has not yet caught up with this international trend. Currently, the methylmercury exposure level of Koreans is known to be very high. The starting point of methylmercury exposure management is inorganic mercury in the general environment, but food intake through methylation is the main exposure source. Along with efforts to reduce mercury in the general environment, food intake management should be undertaken to reduce the human exposure to methylmercury in Korea. PMID:23230465

  14. Methylmercury exposure and health effects.

    PubMed

    Hong, Young-Seoub; Kim, Yu-Mi; Lee, Kyung-Eun

    2012-11-01

    Methylmercury is a hazardous substance that is of interest with regard to environmental health, as inorganic mercury circulating in the general environment is dissolved into freshwater and seawater, condensed through the food chain, ingested by humans, and consequently affects human health. Recently, there has been much interest and discussion regarding the toxicity of methylmercury, the correlation with fish and shellfish intake, and methods of long-term management of the human health effects of methylmercury. What effects chronic exposure to a low concentration of methylmercury has on human health remains controversial. Although the possibility of methylmercury poisoning the heart and blood vessel system, the reproductive system, and the immune system is continuously raised and discussed, and the carcinogenicity of methylmercury is also under discussion, a clear conclusion regarding the human health effects according to exposure level has not yet been drawn. The Joint FAO/WHO Expert Committee on Food Additives proposed to prepare additional fish and shellfish intake recommendations for consumers based on the quantified evaluation of the hazardousness of methylmercury contained in fish and shellfish, methylmercury management in the Korea has not yet caught up with this international trend. Currently, the methylmercury exposure level of Koreans is known to be very high. The starting point of methylmercury exposure management is inorganic mercury in the general environment, but food intake through methylation is the main exposure source. Along with efforts to reduce mercury in the general environment, food intake management should be undertaken to reduce the human exposure to methylmercury in Korea.

  15. Mercury levels in human hair and sex factors

    SciTech Connect

    Shimomura, S.; Kimura, A.; Nakagawa, H.; Takao, M.

    1980-06-01

    Evidence has been presented: (1) that the geometric mean is essential to the statistical analysis of the result of the amount of Hg in hair, and (2) that the individual Hg level in hair must be evaluated by the standard deviation of logarithmic values. The Hg level in hair obtained from 1324 inhabitants on Shikoku Island showed logarithmic-normal distribution curves, with higher values in males than in females. To verify such a sexual difference, hair samples were obtained from male and female children (N = 346), teenagers (N = 300), and adults (N = 354) living in an agricultural area of Tokushima Prefecture on the island. As the result, males were found to have more Hg than females in sexually mature teenagers and adults (P < 0.05 by F test) but not in younger children.

  16. Intraperitoneal injections as a possible means of generating varied levels of methylmercury in the eggs of birds in field studies.

    PubMed

    Heinz, Gary H; Hoffman, David J; Klimstra, Jon D; Stebbins, Katherine R

    2010-05-01

    The ideal study of the effects of methylmercury on the reproductive success of a species of bird would be one in which eggs contained mercury concentrations ranging from controls to very heavily contaminated, all at the same site. Such a study cannot be realized at a Hg-contaminated area or under laboratory conditions but could be achieved by introducing methylmercury into breeding females and allowing them to deposit Hg in their eggs. Female mallards (Anas platyrhynchos) were intraperitoneally injected with solutions of methylmercury chloride dissolved in corn oil, propylene glycol, dimethyl sulfoxide, mineral oil, Olestra, Crisco, lard, hard paraffin, and a combination of hard and soft paraffin. In some cases, egg laying was delayed, as a result of either the solvent itself (in the case of Olestra, Crisco, and lard) or the highest concentration of methylmercury chloride (500 microg/g) in some of the solvents. Mercury in eggs ranged from a control level (<0.1 microg/g) to approximately 14 microg/g on a wet weight basis, which more than covers the range of concentrations reported in wild bird eggs. Mercury concentrations in a series of eggs from the same female declined mostly as a result of excretion of Hg in prior eggs and not because of the length of time since the injection. Intraperitoneal injections hold promise in field studies in which one would like to study the reproductive effects of a wide range of methylmercury levels in the eggs of a wild bird and under the natural conditions that exist in the field. Copyright (c) 2010 SETAC.

  17. Intraperitoneal injections as a possible means of generating varied levels of methylmercury in the eggs of birds in field studies

    USGS Publications Warehouse

    Heinz, Gary H.; Hoffman, David J.; Klimstra, Jon D.; Stebbins, Katherine R.

    2010-01-01

    The ideal study of the effects of methylmercury on the reproductive success of a species of bird would be one in which eggs contained mercury concentrations ranging from controls to very heavily contaminated, all at the same site. Such a study cannot be realized at a mercury contaminated area or under laboratory conditions, but could be achieved by introducing methylmercury into breeding females and allowing them to deposit mercury in their eggs. Female mallards (Anas platyrhynchos) were intraperitoneally injected with solutions of methylmercury chloride dissolved in corn oil, propylene glycol, dimethyl sulfoxide, mineral oil, Olestra, Crisco, lard, hard paraffin, and a combination of hard and soft paraffin. In some cases, egg laying was delayed, either due to the solvent itself (in the case of Olestra, Crisco, and lard) or to the highest concentration of methylmercury chloride (500 μg/g) in some of the solvents. Mercury in eggs ranged from a control level (< 0.1 μg/g) to approximately 14 μg/g on a wet weight basis, which more than covers the range of concentrations reported in wild bird eggs. Mercury concentrations in a series of eggs from the same female declined mostly due to excretion of mercury in prior eggs and not because of the length of time since the injection. Intraperitoneal injections hold promise in field studies where one would like to study the reproductive effects of a wide range of methylmercury levels in the eggs of a wild bird and under the natural conditions that exist in the field.

  18. Total mercury and methylmercury levels in fish from hydroelectric reservoirs in Tanzania.

    PubMed

    Ikingura, J R; Akagi, H

    2003-03-20

    Total mercury (THg) and methylmercury (MeHg) levels have been determined in fish species representing various tropic levels in four major hydroelectric reservoirs (Mtera, Kidatu, Hale-Pangani, Nyumba ya Mungu) located in two distinct geographical areas in Tanzania. The Mtera and Kidatu reservoirs are located along the Great Ruaha River drainage basin in the southern central part of the country while the other reservoirs are located within the Pangani River basin in the north eastern part of Tanzania. Fish mercury levels ranged from 5 to 143 microg/kg (mean 40 microg/kg wet weight) in the Mtera Reservoir, and from 7 to 119 microg/kg (mean 21 microg/kg) in the Kidatu Reservoir downstream of the Great Ruaha River. The lowest THg levels, in the range 1-10 microg/kg (mean 5 microg/kg), were found in fish from the Nyumba ya Mungu (NyM) Reservoir, which is one of the oldest reservoirs in the country. Fish mercury levels in the Pangani and Hale mini-reservoirs, downstream of the NyM Reservoir, were in the order of 3-263 microg/kg, with an average level of 21 microg/kg. These THg levels are among the lowest to be reported in freshwater fish from hydroelectric reservoirs. Approximately 56-100% of the total mercury in the fish was methylmercury. Herbivorous fish species contained lower THg levels than the piscivorous species; this was consistent with similar findings in other fish studies. In general the fish from the Tanzanian reservoirs contained very low mercury concentrations, and differed markedly from fish in hydroelectric reservoirs of similar age in temperate and other regions, which are reported to contain elevated mercury concentrations. The low levels of mercury in the fish correlated with low background concentrations of THg in sediment and flooded soil (mean 2-8 microg/kg dry weight) in the reservoir surroundings. This suggested a relatively clean reservoir environment that has not been significantly impacted by mercury contamination from natural or anthropogenic

  19. Allergen Levels in the Hair of Different Cattle Breeds.

    PubMed

    Zahradnik, Eva; Sander, Ingrid; Brüning, Thomas; Raulf, Monika

    2015-01-01

    Cattle are well-known sources of respiratory allergens in agricultural environments. Breed-specific differences in Bos d 2 (a major bovine allergen) levels in cattle hair have been previously suggested but not fully characterized. Therefore, the aim of the current study was to determine whether hair from common cattle breeds differs in protein and allergen content. In total, 80 hair samples from 16 different cattle breeds were analyzed. The protein concentration was determined using the Bradford assay. The allergen content was measured using a sandwich ELISA based on polyclonal antibodies against a bovine hair protein extract and a commercial immunoassay based on monoclonal antibodies against Bos d 2. Results are given in micrograms per gram of hair. Statistical analysis was performed using the Kruskal-Wallis test and Spearman's rank correlation. A wide variability in all 3 tested parameters was observed between the individual samples. The protein content differed by about 35-fold (0.3-12 mg/g), the bovine hair allergen content differed by about 500-fold (37-18,553 µg/g), and the Bos d 2 content differed by about 1,200-fold (5-6,323 µg/g). Protein, bovine hair allergen, and Bod d 2 values correlated strongly and significantly with one another. The median Bos d 2/bovine hair allergen ratio was 0.28. No significant differences were found between the most common breeds in Germany (Simmental, Holstein, and Braunvieh) and a group of rare breeds or between female and male animals. The results confirm a high variability in allergen levels between individual animals but also indicate that allergen production is related neither to the breed nor to gender. © 2015 S. Karger AG, Basel.

  20. Mercury and docosahexaenoic acid levels in maternal and cord blood in relation to segmental maternal hair mercury concentrations at parturition.

    PubMed

    Sakamoto, Mineshi; Chan, Hing Man; Domingo, José L; Kawakami, Shoichi; Murata, Katsuyuki

    2012-09-01

    Fish is a major source of harmful methylmercury (MeHg) and beneficial docosahexaenoic acid (DHA) in the developing brain. In this study, we investigated the correlations among maternal and umbilical cord (cord) MeHg and DHA levels at parturition, and mercury (Hg) concentration in 1-cm incremental segments hair samples which grew during gestation representing monthly MeHg exposure levels throughout the period. Whole blood Hg and plasma DHA levels were measured in blood sample pairs collected from 54 mothers at early gestation and parturition, and in cord blood. Maternal hair samples were collected at parturition, and Hg concentrations were measured in 1-cm incremental segments. Hg level in mothers at parturition was slightly lower than that at early gestation and the level in cord blood were approximately 1.9 times higher than that in mothers at parturition. On the other hand, DHA level in mothers at parturition was approximately 2.3 and 1.6 times higher than those in mothers at early gestation and in cord plasma, respectively. These results indicate that kinetics of these chemicals in mothers during gestation and placental transfer are completely different. However, Hg and DHA levels had significant positive correlation in fetal circulation. The cord blood Hg showed the strongest correlation with maternal hair Hg in the first 1-cm segment from the scalp at parturition (r=0.87), indicating that fetal MeHg level reflects maternal MeHg burden at late gestation. In contrast, maternal and cord plasma DHA concentrations at parturition showed the highest correlation coefficients with Hg in the fifth (r=0.43) and fourth (r=0.38) 1-cm hair segments, suggesting that maternal and fetal DHA levels reflects maternal fish intake during mid-gestation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Brain and tissue levels of mercury after chronic methylmercury exposure in the monkey

    SciTech Connect

    Rice, D.C.

    1989-01-01

    Estimated half-lives of mercury following methylmercury exposure in humans are 52-93 d for whole body and 49-164 d for blood. In its most recent 1980 review, the World Health Organization concluded that there was no evidence to suggest that brain half-life differed from whole-body half-life. In the present study, female monkeys (Macaca fascicularis) were dosed for at least 1.7 yr with 10, 25, or 50 micrograms/kg.d of mercury as methylmercuric chloride. Dosing was discontinued, and blood half-life was determined to be about 14 d. Approximately 230 d after cessation of dosing, monkeys were sacrificed and organ and regional brain total mercury levels determined. One monkey that died while still being dosed had brain mercury levels three times higher than levels in blood. Theoretical calculations were performed assuming steady-state brain:blood ratios of 3, 5, or 10. Brain mercury levels were at least three orders of magnitude higher than those predicted by assuming the half-life in brain to be the same as that in blood. Estimated half-lives in brain were between 56 (brain:blood ratio of 3) and 38 (brain:blood ratio of 10) d. In addition, there was a dose-dependent difference in half-lives for some brain regions. These data clearly indicate that brain half-life is considerably longer than blood half-life in the monkey under conditions of chronic dosing.

  2. Exposures of dental professionals to elemental mercury and methylmercury.

    PubMed

    Goodrich, Jaclyn M; Chou, Hwai-Nan; Gruninger, Stephen E; Franzblau, Alfred; Basu, Niladri

    2016-01-01

    Mercury (Hg) exposure, a worldwide public health concern, predominantly takes two forms--methylmercury from fish consumption and elemental Hg from dental amalgam restorations. We recruited 630 dental professionals from an American Dental Association meeting to assess Hg body burden and primary sources of exposure in a dually exposed population. Participants described occupational practices and fish consumption patterns via questionnaire. Hg levels in biomarkers of elemental Hg (urine) and methylmercury (hair and blood) were measured with a Direct Mercury Analyzer-80 and were higher than the general US population. Geometric means (95% CI) were 1.28 (1.19-1.37) μg/l in urine, 0.60 (0.54-0.67) μg/g in hair and 3.67 (3.38-3.98) μg/l in blood. In multivariable linear regression, personal amalgams predicted urine Hg levels along with total years in dentistry, amalgams handled, working hours and sex. Fish consumption patterns predicted hair and blood Hg levels, which were higher among Asians compared with Caucasians. Five species contributed the majority of the estimated Hg intake from fish--swordfish, fresh tuna, white canned tuna, whitefish and king mackerel. When studying populations with occupational exposure to Hg, it is important to assess environmental exposures to both elemental Hg and methylmercury as these constitute a large proportion of total exposure.

  3. Exposures of Dental Professionals to Elemental Mercury and Methylmercury

    PubMed Central

    Goodrich, Jaclyn M.; Chou, Hwai-Nan; Gruninger, Stephen E.; Franzblau, Alfred; Basu, Niladri

    2015-01-01

    Mercury (Hg) exposure, a worldwide public health concern, predominantly takes two forms – methylmercury from fish consumption and elemental Hg from dental amalgam restorations. We recruited 630 dental professionals from an American Dental Association meeting to assess Hg body burden and primary sources of exposure in a dually-exposed population. Participants described occupational practices and fish consumption patterns via questionnaire. Mercury levels in biomarkers of elemental Hg (urine) and methylmercury (hair, blood) were measured with a Direct Mercury Analyzer-80 and were higher than the general U.S. population. Geometric means (95% CI) were 1.28 (1.19–1.37) µg/L in urine, 0.60 (0.54–0.67) µg/g in hair, and 3.67 (3.38–3.98) µg/L in blood. In multivariable linear regression, personal amalgams predicted urine Hg levels along with total years in dentistry, amalgams handled, working hours, and sex. Fish consumption patterns predicted hair and blood Hg levels which were higher among Asians compared with Caucasians. Five species contributed the majority of the estimated Hg intake from fish - swordfish, fresh tuna, white canned tuna, whitefish, and king mackerel. When studying populations with occupational exposure to Hg, it is important to assess environmental exposures to both elemental Hg and methylmercury as these constitute a large proportion of total exposure. PMID:26329138

  4. Mercury and methylmercury levels in the main traded fish species in Hong Kong.

    PubMed

    Chung, S W C; Kwong, K P; Tang, A S P; Xiao, Y; Ho, P Y Y

    2008-01-01

    Levels of total mercury (tHg) and mono-methylmercury (MeHg) were measured in 280 different fish, including fresh/frozen raw whole fish of 89 different species and canned tuna fish of three different species, that are traded mainly in Hong Kong, China. These samples were purchased from different commercial outlets between April and August 2007. All samples of raw whole fish were identified at species level by the Agriculture, Fisheries and Conservation Department. The range for tHg and MeHg of all samples were 3-1370 and 3-1010 µg kg(-1), respectively, with medians of 63 and 48 µg kg(-1), respectively. The results show that, according to Hong Kong legislation, the products on the market are generally 'safe'. A total of 277 samples (99?) contained tHg and MeHg below the legal limit of 500 µg kg(-1). The remaining three samples of alfonsino (species: Beryx splendens) were found to contain tHg and MeHg at levels higher than 500 µg kg(-1) (tHg: 609-1370 µg kg(-1); MeHg: 509-1010 µg kg(-1)). The ratios of MeHg to tHg in the different fish species ranged from 0.46 to 0.99.

  5. Methylmercury level in umbilical cords from patients with congenital Minamata disease.

    PubMed

    Harada, M; Akagi, H; Tsuda, T; Kizaki, T; Ohno, H

    1999-08-30

    A total of 151 umbilical cords during the period from 1950 to 1969 were collected from the residents of the Minamata area (including 25 patients with congenital Minamata disease) for methylmercury (MeHg) analysis. When the MeHg discharge from the Chisso Company's Minamata factory into the Minamata Bay is compared with the incidence of congenital Minamata disease, the abrupt increase of the former in 1952 [Nishimura H. Chem. Today 1998;323:60-66] was found to precede that of the latter by approximately 2 years, thereby indicating that MeHg is the cause of the disaster. This was confirmed by the elevated levels of MeHg in the umbilical cords from residents of the Minamata area [from 0.35 +/- 0.30 (S.D.) ppm in 1952 to 0.96 +/- 0.75 ppm in 1955], the MeHg levels (1.60 +/- 1.00 ppm) in the cords from patients with congenital Minamata disease showing the highest values [P < 0.01 vs. acquired Minamata disease (0.72 +/- 0.65 ppm), mental retardation (0.74 +/- 0.64 ppm), other diseases (0.22 +/- 0.15 ppm), and no symptoms (0.28 +/- 0.20 ppm), respectively]. Thus, in order to fill a gap, which extends over a long period of time, in studies on environmental Hg pollution, umbilical cord samples were considered to be a useful tool.

  6. Re-evaluation of the reference dose for methylmercury and assessment of current exposure levels

    SciTech Connect

    Stern, A.H. )

    1993-06-01

    Methylmercury (Me-Hg) is widely distributed through freshwater and saltwater food chains and human consumption of fish and shellfish has lead to widespread exposure. Both the US EPA Reference Dose (0.3 [mu]g/kg/day) and the FAO/WHO Permissible Tolerable Weekly Intake (3.3 [mu]g/kg/week) are currently based on the prevention of paraesthesia in adult and older children. However, Me-Hg exposure in utero is known to result in a range of developmental neurologic effects including clinical CNS symptoms and delayed onset of walking. Based on a critical review of development toxicity data from human and animal studies, it is concluded that current guidelines for the prevention of paraesthesia are not adequate to address developmental effects. A dose of 0.07 [mu]g/kg/day is suggested as the best estimate of a potential reference dose for developmental effects. Data on nationwide fish consumption rates and Me-Hg levels in fish/seafood weighted by proportion of the catch intended for human consumption are analyzed in a Monte Carlo simulation to derive a probability distribution of background Me-Hg exposure. While various uncertainties in the toxicologic and exposure data limit the precision with which health risk can be estimated, this analysis suggests that at current levels of Me-Hg exposure, a significant fraction of women of childbearing age have exposures above this suggested reference dose.

  7. Differentiated availability of geochemical mercury pools controls methylmercury levels in estuarine sediment and biota.

    PubMed

    Jonsson, Sofi; Skyllberg, Ulf; Nilsson, Mats B; Lundberg, Erik; Andersson, Agneta; Björn, Erik

    2014-08-20

    Neurotoxic methylmercury (MeHg) formed from inorganic divalent mercury (Hg(II)) accumulates in aquatic biota and remains at high levels worldwide. It is poorly understood to what extent different geochemical Hg pools contribute to these levels. Here we report quantitative data on MeHg formation and bioaccumulation, in mesocosm water-sediment model ecosystems, using five Hg(II) and MeHg isotope tracers simulating recent Hg inputs to the water phase and Hg stored in sediment as bound to natural organic matter or as metacinnabar. Calculations for an estuarine ecosystem suggest that the chemical speciation of Hg(II) solid/adsorbed phases control the sediment Hg pool's contribution to MeHg, but that input of MeHg from terrestrial and atmospheric sources bioaccumulates to a substantially greater extent than MeHg formed in situ in sediment. Our findings emphasize the importance of MeHg loadings from catchment runoff to MeHg content in estuarine biota and we suggest that this contribution has been underestimated.

  8. Methylmercury and Pregnancy

    MedlinePlus

    ... is methylmercury? Methylmercury is a toxic form of mercury found mostly in water, soil, plants and animals. Methylmercury (organic mercury) is different from elemental mercury (thermometers, dental amalgams). ...

  9. Cutaneous Retinoic Acid Levels Determine Hair Follicle Development and Downgrowth*

    PubMed Central

    Okano, Junko; Levy, Clara; Lichti, Ulrike; Sun, Hong-Wei; Yuspa, Stuart H.; Sakai, Yasuo; Morasso, Maria I.

    2012-01-01

    Retinoic acid (RA) is essential during embryogenesis and for tissue homeostasis, whereas excess RA is well known as a teratogen. In humans, excess RA is associated with hair loss. In the present study, we demonstrate that specific levels of RA, regulated by Cyp26b1, one of the RA-degrading enzymes, are required for hair follicle (hf) morphogenesis. Mice with embryonic ablation of Cyp26b1 (Cyp26b1−/−) have excessive endogenous RA, resulting in arrest of hf growth at the hair germ stage. The altered hf development is rescued by grafting the mutant skin on immunodeficient mice. Our results show that normalization of RA levels is associated with reinitiation of hf development. Conditional deficiency of Cyp26b1 in the dermis (En1Cre;Cyp26b1f/−) results in decreased hair follicle density and specific effect on hair type, indicating that RA levels also influence regulators of hair bending. Our results support the model of RA-dependent dermal signals regulating hf downgrowth and bending. To elucidate target gene pathways of RA, we performed microarray and RNA-Seq profiling of genes differentially expressed in Cyp26b1−/− skin and En1Cre;Cyp26b1f/− tissues. We show specific effects on the Wnt-catenin pathway and on members of the Runx, Fox, and Sox transcription factor families, indicating that RA modulates pathways and factors implicated in hf downgrowth and bending. Our results establish that proper RA distribution is essential for morphogenesis, development, and differentiation of hfs. PMID:23007396

  10. Methylmercury levels and bioaccumulation in the aquatic food web of a highly mercury-contaminated reservoir.

    PubMed

    Carrasco, Luis; Benejam, Lluís; Benito, Josep; Bayona, Josep M; Díez, Sergi

    2011-10-01

    The low Ebro River basin (NE Spain) represents a particular case of chronic and long-term mercury pollution due to the presence of an industrial waste (up to 436 μg/g of Hg) coming from a chlor-alkali plant Albeit high total mercury (THg) levels have been previously described in several aquatic species from the surveyed area, methylmercury (MeHg) values in fish individuals have never been reported. Accordingly, in order to investigate bioaccumulation patterns at different levels of the aquatic food web of such polluted area, crayfish and various fish species, were analysed for THg and MeHg content. At the hot spot, THg mean values of crayfish muscle tissue and hepatopancreas were 10 and 15 times, respectively, greater than the local background level. Higher mean THg concentrations were detected in piscivorous (THg=0.848 ± 0.476 μg/g wet weight (ww); MeHg=0.672 ± 0.364 μg/g ww) than in non-piscivorous fish (THg=0.305 ± 0.163 μg/g ww; MeHg=0.278 ± 0.239 μg/g ww). Although these results indicated that THg in fish increased significantly with increasing trophic position, the percentage of the methylated form of Hg was not strongly influenced by differences in relative trophic position. This is an important finding, since the fraction of THg as MeHg in the top fish predator was unexpectedly lower than for other species of the aquatic food chain. Moreover, mean THg concentrations in piscivorous fish exceed the maximum level recommended for human consumption. From our findings, it is clear that for this specific polluted system, speciation becomes almost mandatory when risk assessment is based on MeHg, since single measurements of THg are inadequate and could lead to an over- or under-estimation of contamination levels.

  11. Cortisol levels in hair of East Greenland polar bears.

    PubMed

    Bechshøft, T Ø; Sonne, C; Dietz, R; Born, E W; Novak, M A; Henchey, E; Meyer, J S

    2011-01-15

    To demonstrate the ability to assess long-term hypothalamic-pituitary-adrenocortical (HPA) axis activity in polar bears (Ursus maritimus), a pilot study was conducted in which cortisol concentrations was analyzed in hair from 7 female (3-19 years) and 10 male (6-19 years) East Greenland polar bears sampled in 1994-2006. The hair was chosen as matrix as it is non-invasive, seasonally harmonized, and has been validated as an index of long-term changes in cortisol levels. The samples were categorized according to contamination: eight were clean (2 females, 6 males), 5 had been contaminated with bear blood (2 F, 3 M), and 4 with bear fat (3 F, 1 M). There was no significant difference in cortisol concentration between the three categories after external contamination was removed. However, contaminated hair samples should be cleaned before cortisol determination. Average hair cortisol concentration was 8.90 pg/mg (range: 5.5 to 16.4 pg/mg). There was no significant correlation between cortisol concentration and age (p=0.81) or sampling year (p=0.11). However, females had higher mean cortisol concentration than males (females mean: 11.0 pg/mg, males: 7.3 pg/mg; p=0.01). The study showed that polar bear hair contains measurable amounts of cortisol and that cortisol in hair may be used in studies of long-term stress in polar bears. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Oxidative Modification in Human Hair: The Effect of the Levels of Cu (II) Ions, UV Exposure and Hair Pigmentation.

    PubMed

    Grosvenor, Anita J; Marsh, Jennifer; Thomas, Ancy; Vernon, James A; Harland, Duane P; Clerens, Stefan; Dyer, Jolon M

    2016-01-01

    Protein oxidative degradation is implicated in a wide range of deleterious effects. For human hair, this oxidative damage can lead to significant observable changes in fiber physical and visual properties. A redox proteomic approach was applied to map molecular modification in human hair proteins and correlate this modification with the abundance of copper (II) ions, the levels of UV exposure and the general level of hair pigmentation. An increase in oxidative modification was observed with increasing copper (II) ion levels, regardless of the pigmentation level. Significantly, increased protein oxidative modification was also observed to occur in both lightly and darkly pigmented hair tresses even in the absence of irradiation, albeit at lower relative levels. Modification levels increased with increased copper (II) ion concentration. This new finding indicates that the level of copper (II) ions in human hair plays a key role in mediating protein oxidation, with or without exposure to UV light. Overall, these results strongly suggest that minimization of the level of copper (II) ions in human hair will mitigate and/or slow protein oxidative modification and therefore lower overall hair damage. © 2015 The American Society of Photobiology.

  13. Coat and hair color: hair cortisol and serotonin levels in lactating Holstein cows under heat stress conditions.

    PubMed

    Ghassemi Nejad, Jalil; Kim, Byong-Wan; Lee, Bae-Hun; Sung, Kyung-Il

    2017-01-01

    The deleterious effects of heat stress on animal health are being increasingly recognized. This study aimed to determine hair cortisol (HC) and serotonin levels in lactating Holstein cows under heat stress conditions with different coat and hair-cut color. Forty-five multiparous lactating Holstein cows (days in milk = 130 ± 47, body weight = 753 ± 85 kg) were divided to two main groups of over 80% black coat color (BC) and over 85% white coat color (WC) visually observed based on registry certificates and subdividing to black hair sample (BH) and white hair samples (WH) in 2 × 2 factorial arrangements. Hair samples were taken from the forehead of the individuals. Higher HC levels were observed in BC than WC cows (P < 0.05). No differences were found in HC levels between BH and WH groups (P > 0.05). Serotonin levels showed no difference between BC and WC (P > 0.05). Interaction between coat color and hair color was not significant (P > 0.05). The cortisol levels in hair are not affected by pigmentation. However, pigmentation within the coat alters cortisol levels. In conclusion, white coat color retains less cortisol than the black coat. Therefore, white coats are preferable for dairy cows under heat stress conditions.

  14. Total mercury levels in hair, toenail, and urine among women free from occupational exposure and their relations to renal tubular function

    SciTech Connect

    Ohno, Tomoko; Sakamoto, Mineshi; Kurosawa, Tomoko; Dakeishi, Miwako; Iwata, Toyoto; Murata, Katsuyuki . E-mail: winestem@med.akita-u.ac.jp

    2007-02-15

    To investigate the relations among total mercury levels in hair, toenail, and urine, together with potential effects of methylmercury intake on renal tubular function, we determined their levels, and urinary N-acetyl-{beta}-d-glucosaminidase activity (NAG) and {alpha}{sub 1}-microglobulin (AMG) in 59 women free from occupational exposures, and estimated daily mercury intakes from fish and other seafood using a food frequency questionnaire. Mercury levels (mean+/-SD) in the women were 1.51+/-0.91{mu}g/g in hair, 0.59+/-0.32{mu}g/g in toenail, and 0.86+/-0.66{mu}g/g creatinine in urine; and, there were positive correlations among them (P<0.001). The daily mercury intake of 9.15+/-7.84{mu}g/day was significantly correlated with total mercury levels in hair, toenail, and urine (r=0.551, 0.537, and 0.604, P<0.001). Among the women, the NAG and AMG were positively correlated with both the daily mercury intake and mercury levels in hair, toenail, and urine (P<0.01); and, these relations were almost similar when using multiple regression analysis to adjust for possible confounders such as urinary cadmium (0.47+/-0.28{mu}g/g creatinine) and smoking status. In conclusion, mercury resulting from fish consumption can explain total mercury levels in hair, toenail, and urine to some degree (about 30%), partly through the degradation into the inorganic form, and it may confound the renal tubular effect of other nephrotoxic agents. Also, the following equation may be applicable to the population neither with dental amalgam fillings nor with occupational exposures: [hair mercury ({mu}g/g)]=2.44x[toenail mercury ({mu}g/g)].

  15. [Regeneration of photoreceptor organs in freshwater planarians at different levels of accumulation of natural methylmercury compounds].

    PubMed

    Medvedev, I V; Gremiachikh, V A; Zheltov, S V; Bogdanenko, O V; Aksenova, I A

    2006-01-01

    The effects of natural methylmercury compounds on regeneration of photoreceptor organs were studied in three freshwater planarians: Polycelis tenuis, Dugesia lugubris, and D. tigrina. Accumulation of methyl mercury in the planarian body suppressed regeneration of P. tenuis with numerous photoreceptor organs to a greater extent than in two other planarians that have only two eyes. High methyl mercury concentrations inhibited the restoration of photoreceptor organs in asexual and sexual D. tigrina races.

  16. Hair loss in females after sleeve gastrectomy: predictive value of serum zinc and iron levels.

    PubMed

    Ruiz-Tovar, Jaime; Oller, Inmaculada; Llavero, Carolina; Zubiaga, Lorea; Diez, María; Arroyo, Antonio; Calero, Alicia; Calpena, Rafael

    2014-05-01

    A common complication after bariatric surgery is hair loss, which is related to rapid weight reduction, but zinc, iron, and other micronutrient deficiencies can also be involved. Little is studied after laparoscopic sleeve gastrectomy (LSG). A prospective observational study was performed of 42 morbidly obese females undergoing LSG. Incidence of hair loss was monitored. Micronutrients were investigated preoperatively and three, six, and 12 months after surgery. Sixteen patients (41%) reported hair loss in the postoperative course. A significant association was observed between hair loss and zinc levels (P = 0.021) but mean zinc levels were within the normal range in patients reporting hair loss. Only three patients (7.7%) presented low zinc levels, all of them reporting hair loss. There was also a significant association between iron levels and alopecia (P = 0.017), but mean values of the patients with hair loss were within normal range. Only four patients (10.2%) presented low iron levels, all of them presenting hair loss. A variable consisting of the addition of zinc + iron showed a significant association with hair loss (P = 0.013). A cutoff point was established in 115 (odds ratio, 4; P = 0.006). All the patients but two reporting hair loss presented addition levels under 115. This variable showed sensibility 88 per cent, specificity 84 per cent, positive predictive value 79 per cent, and negative predictive value 91 per cent to predict hair loss. Hair loss is a frequent condition after sleeve gastrectomy. In most cases, iron and zinc levels are within the normal range. The variable addition (zinc + iron) is a good predictor of hair loss. Patients with addition levels below 115 are fourfold more susceptible to present hair loss. In these cases, zinc supplements achieve the stop of hair loss in most cases.

  17. Fish consumption patterns and hair mercury levels in children and their mothers in 17 EU countries.

    PubMed

    Castaño, Argelia; Cutanda, Francisco; Esteban, Marta; Pärt, Peter; Navarro, Carmen; Gómez, Silvia; Rosado, Montserrat; López, Ana; López, Estrella; Exley, Karen; Schindler, Birgit K; Govarts, Eva; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Fiddicke, Ulrike; Koch, Holger; Angerer, Jürgen; Den Hond, Elly; Schoeters, Greet; Sepai, Ovnair; Horvat, Milena; Knudsen, Lisbeth E; Aerts, Dominique; Joas, Anke; Biot, Pierre; Joas, Reinhard; Jiménez-Guerrero, José A; Diaz, Gema; Pirard, Catherine; Katsonouri, Andromachi; Cerna, Milena; Gutleb, Arno C; Ligocka, Danuta; Reis, Fátima M; Berglund, Marika; Lupsa, Ioana-Rodica; Halzlová, Katarína; Charlier, Corinne; Cullen, Elizabeth; Hadjipanayis, Adamos; Krsková, Andrea; Jensen, Janne F; Nielsen, Jeanette K; Schwedler, Gerda; Wilhelm, Michael; Rudnai, Peter; Középesy, Szilvia; Davidson, Fred; Fischer, Mark E; Janasik, Beata; Namorado, Sónia; Gurzau, Anca E; Jajcaj, Michal; Mazej, Darja; Tratnik, Janja Snoj; Larsson, Kristin; Lehmann, Andrea; Crettaz, Pierre; Lavranos, Giagkos; Posada, Manuel

    2015-08-01

    The toxicity of methylmercury (MeHg) in humans is well established and the main source of exposure is via the consumption of large marine fish and mammals. Of particular concern are the potential neurodevelopmental effects of early life exposure to low-levels of MeHg. Therefore, it is important that pregnant women, children and women of childbearing age are, as far as possible, protected from MeHg exposure. Within the European project DEMOCOPHES, we have analyzed mercury (Hg) in hair in 1799 mother-child pairs from 17 European countries using a strictly harmonized protocol for mercury analysis. Parallel, harmonized questionnaires on dietary habits provided information on consumption patterns of fish and marine products. After hierarchical cluster analysis of consumption habits of the mother-child pairs, the DEMOCOPHES cohort can be classified into two branches of approximately similar size: one with high fish consumption (H) and another with low consumption (L). All countries have representatives in both branches, but Belgium, Denmark, Spain, Portugal and Sweden have twice as many or more mother-child pairs in H than in L. For Switzerland, Czech Republic, Hungary, Poland, Romania, Slovenia and Slovakia the situation is the opposite, with more representatives in L than H. There is a strong correlation (r=0.72) in hair mercury concentration between the mother and child in the same family, which indicates that they have a similar exposure situation. The clustering of mother-child pairs on basis of their fish consumption revealed some interesting patterns. One is that for the same sea fish consumption, other food items of marine origin, like seafood products or shellfish, contribute significantly to the mercury levels in hair. We conclude that additional studies are needed to assess and quantify exposure to mercury from seafood products, in particular. The cluster analysis also showed that 95% of mothers who consume once per week fish only, and no other marine products

  18. Enhanced reproduction in mallards fed a low level of methylmercury: an apparent case of hormesis.

    PubMed

    Heinz, Gary H; Hoffman, David J; Klimstra, Jon D; Stebbins, Katherine R

    2010-03-01

    Breeding pairs of mallards (Anas platyrhynchos) were fed a control diet or a diet containing 0.5 microg/g mercury (Hg) in the form of methylmercury chloride. There were no effects of Hg on adult weights and no overt signs of Hg poisoning in adults. The Hg-containing diet had no effect on fertility of eggs, but hatching success of eggs was significantly higher for females fed 0.5 microg/g Hg (71.8%) than for controls (57.5%). Survival of ducklings through 6 d of age was the same (97.8%) for controls and mallards fed 0.5 microg/g mercury. However, the mean number of ducklings produced per female was significantly higher for the pairs fed 0.5 microg/g Hg (21.4) than for controls (16.8). Although mercury in the parents' diet had no effect on mean duckling weights at hatching, ducklings from parents fed 0.5 microg/g Hg weighed significantly more (mean = 87.2 g) at 6 d of age than did control ducklings (81.0 g). The mean concentration of Hg in eggs laid by parents fed 0.5 microg/g mercury was 0.81 microg/g on a wet-weight basis. At this time, one cannot rule out the possibility that low concentrations of Hg in eggs may be beneficial, and this possibility should be considered when setting regulatory thresholds for methylmercury.

  19. Enhanced reproduction in mallards fed a low level of methylmercury: An apparent case of hormesis

    USGS Publications Warehouse

    Heinz, G.H.; Hoffman, D.J.; Klimstra, J.D.; Stebbins, K.R.

    2010-01-01

    Breeding pairs of mallards (Anas platyrhynchos) were fed a control diet or a diet containing 0.5 mg/g mercury (Hg) in the form of methylmercury chloride. There were no effects of Hg on adult weights and no overt signs of Hg poisoning in adults. The Hg-containing diet had no effect on fertility of eggs, but hatching success of eggs was significantly higher for females fed 0.5 ??g/g Hg (71.8%) than for controls (57.5%). Survival of ducklings through 6 d of age was the same (97.8%) for controls and mallards fed 0.5 ??g/g mercury. However, the mean number of ducklings produced per female was significantly higher for the pairs fed 0.5 ??g/g Hg (21.4) than for controls (16.8). Although mercury in the parents' diet had no effect on mean duckling weights at hatching, ducklings from parents fed 0.5 mg/g Hg weighed significantly more (mean = 87.2 g) at 6 d of age than did control ducklings (81.0 g). The mean concentration of Hg in eggs laid by parents fed 0.5 ??g/g mercury was 0.81 ??g/g on a wet-weight basis. At this time, one cannot rule out the possibility that low concentrations of Hg in eggs may be beneficial, and this possibility should be considered when setting regulatory thresholds for methylmercury. ?? 2009 SETAC.

  20. Higher hair nicotine level in children compared to mother living with smoking father in Malaysia.

    PubMed

    Mohamed, Nur Nadia; Loy, See Ling; Man, Che Nin; Al-Mamun, Abdullah; Jan Mohamed, Hamid Jan

    2016-11-01

    The objectives of this study are to determine parental and children's hair nicotine levels, their relationships as well as to investigate the association of smoking status of the fathers with mothers' and children's hair nicotine. A cross-sectional study design was conducted among 124 families who were participants of the Universiti Sains Malaysia Pregnancy Cohort Study. Both parents with their 2 years old children joined this study. A total of 92 hair samples of fathers, 124 hair samples of mothers and 111 hair samples of children were collected and analyzed by gas chromatography-mass spectrometry. Of total, 52.4 % of the fathers reported smoking. None of the mothers were smokers. Hair nicotine levels of fathers were found to be significantly correlated with mothers (r = 0.233, p = 0.026) and children (r = 0.508, p < 0.001). Children living with smoking fathers had significantly higher median hair nicotine level compared to the children of non-smoking fathers (6.08 vs 0.22 ng/mg, p = 0.046). However, this association was not seen in the mothers. Quantile regression showed significant association between fathers' and children's hair nicotine. There is a positive relationship between fathers' hair nicotine with mother's and children's hair nicotine. Living with smoking fathers can contribute to higher hair nicotine levels in children but not in mothers.

  1. Hair Analysis Provides a Historical Record of Cortisol Levels in Cushing’s Syndrome

    PubMed Central

    Thomson, S.; Koren, G.; Fraser, L.-A.; Rieder, M.; Friedman, T. C.; Van Uum, S. H. M.

    2010-01-01

    The severity of Cushing’s Syndrome (CS) depends on the duration and extent of the exposure to excess glucocorticoids. Current measurements of cortisol in serum, saliva and urine reflect systemic cortisol levels at the time of sample collection, but cannot assess past cortisol levels. Hair cortisol levels may be increased in patients with CS, and, as hair grows about 1 cm/month, measurement of hair cortisol may provide historical information on the development of hypercortisolism. We attempted to measure cortisol in hair in relation to clinical course in six female patients with CS and in 32 healthy volunteers in 1 cm hair sections. Hair cortisol content was measured using a commercially available salivary cortisol immune assay with a protocol modified for use with hair. Hair cortisol levels were higher in patients with CS than in controls, the medians (ranges) were 679 (279–2500) and 116 (26–204) ng/g respectively (P <0.001). Segmental hair analysis provided information for up to 18 months before time of sampling. Hair cortisol concentrations appeared to vary in accordance with the clinical course. Based on these data, we suggest that hair cortisol measurement is a novel method for assessing dynamic systemic cortisol exposure and provides unique historical information on variation in cortisol, and that more research is required to fully understand the utility and limits of this technique. PMID:19609841

  2. Methylmercury and elemental mercury differentially associate with blood pressure among dental professionals

    PubMed Central

    Goodrich, Jaclyn M.; Wang, Yi; Gillespie, Brenda; Werner, Robert; Franzblau, Alfred; Basu, Niladri

    2013-01-01

    Methylmercury-associated effects on the cardiovascular system have been documented though discrepancies exist, and most studied populations experience elevated methylmercury exposures. No paper has investigated the impact of low-level elemental (inorganic) mercury exposure on cardiovascular risk in humans. The purpose of this study was to increase understanding of the association between mercury exposure (methylmercury and elemental mercury) and blood pressure measures in a cohort of dental professionals that experience background exposures to both mercury forms. Dental professionals were recruited during the 2010 Michigan Dental Association Annual Convention. Mercury levels in hair and urine samples were analyzed as biomarkers of methylmercury and elemental mercury exposure, respectively. Blood pressure (systolic, diastolic) was measured using an automated device. Distribution of mercury in hair (mean, range: 0.45, 0.02–5.18 μg/g) and urine (0.94, 0.03–5.54 μg/L) correspond well with the US National Health and Nutrition Examination Survey. Linear regression models revealed significant associations between diastolic blood pressure (adjusted for blood pressure medication use) and hair mercury (n = 262, p = 0.02). Urine mercury results opposed hair mercury in many ways. Notably, elemental mercury exposure was associated with a significant systolic blood pressure decrease (n = 262, p = 0.04) that was driven by the male population. Associations between blood pressure and two forms of mercury were found at exposure levels relevant to the general population, and associations varied according to type of mercury exposure and gender. PMID:22494934

  3. Association of hair dye use with circulating levels of sex hormones in premenopausal Japanese women.

    PubMed

    Nagata, Chisato; Wada, Keiko; Tsuji, Michiko; Hayashi, Makoto; Takeda, Noriyuki; Yasuda, Keigo

    2015-10-01

    Substances identified as animal carcinogens are no longer used as ingredients of hair dyes. However, hair dyes are diverse groups of chemicals, and certain compounds may affect endogenous sex hormone levels. We examined the association between hair dye use and sex hormone levels among premenopausal women. Study subjects were 431 premenopausal Japanese women who had regular menstrual cycles less than 40 days long. Information on the use of hair dyes or hair bleach, the type of hair coloring used, the duration of use and the frequency of application was collected using a self-administered questionnaire. Fasting plasma samples were obtained to measure estradiol, testosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin, follicle-stimulating hormone and luteinizing hormone. After controlling for covariates, the mean plasma total testosterone level was about 14% higher in women who had used hair dyes for 10 or more years than that among women who had never used them (P for trend = 0.02). A similar association was observed when the type of hair dye was restricted to permanent hair dyes. A higher frequency of applying non-permanent hair dyes was marginally significantly associated with higher total and free estradiol levels. Data suggest that long-term use of hair dyes may be associated with an increase in circulating testosterone levels. As this is, to our knowledge, the first study examining the association between hair dye use and sex hormone levels, replication of the results is required. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  4. Hair mercury levels and food consumption in residents from the Pearl River Delta: South China.

    PubMed

    Shao, Dingding; Kang, Yuan; Cheng, Zhang; Wang, Hongsheng; Huang, Minjuan; Wu, Shengchun; Chen, Kunci; Wong, Ming H

    2013-01-15

    The Pearl River Delta (PRD) is located in the Southern part of China and is the main region for fish culture in Guangdong Province. In order to assess the potential health risks associated with dietary consumption of mercury, hair samples from 91 urban, town and fishing village residents, 37 species of fish, cereal, vegetables, and meat samples were collected. The average total mercury (THg) and methylmercury (MeHg) concentrations in hair were 1.08 ± 0.94 and 0.58 ± 0.59 μg/g, respectively. Daily Hg intake via fish consumption is significantly correlated with THg and MeHg accumulated in human hair (r=0.48, p<0.01; r=0.43, p<0.01). The estimated daily intake of Hg via different food types showed that both fish and cereal consumption were the two main routes of Hg exposure for residents in the sampling areas. Besides food intake, smoking was also an important source for daily THg intake in the smoke group, contributing 11-18% to EDI of THg.

  5. Hair Zinc Level Analysis and Correlative Micronutrients in Children Presenting with Malnutrition and Poor Growth.

    PubMed

    Han, Tae Hwan; Lee, Jin; Kim, Yong Joo

    2016-12-01

    Zinc deficiency can induce serious clinical problems in the gastrointestinal (GI) system and immune system and can affect growth and development. It is more severe in younger patients. Chronic zinc deficiency is reflected more precisely in hair than in serum. We studied hair zinc levels and other hair and serum micronutrients in chronic malnourished children to identify which micronutrients are affected or correlated with the other ones. Hair mineral analyses were performed in 56 children (age, 1-15 years) presenting with malnutrition, poor growth, poor appetite, anorexia, with/without other GI symptoms (diarrhea, abdominal pain, constipation) from August 2012 to March 2015. Biochemical studies for macronutrients and major micronutrients were also conducted. Hair zinc deficiency was diagnosed in 88%, and serum zinc deficiency was diagnosed in 55% of the children. There was no statistical correlation between serum and tissue zinc level. Hair zinc levels were highly correlated with serum vitamin D (r=-0.479, p=0.001), which also showed correlation with hair levels of magnesium and calcium. (r=0.564, 0.339, p=0.001, 0.011). Hair calcium level was correlated with serum pre-albumin (r=0.423, p=0.001). These correlations may explain the phenomenon that the major clinical manifestation of zinc deficiency is poor body growth. Clinical symptoms were resolved in most children after zinc supplementation. Hair zinc and mineral analyses are useful as a therapeutic guide in the clinical investigation of children with malnutrition and poor growth.

  6. Relationship between nutritional habits and hair calcium levels in young women.

    PubMed

    Jeruszka-Bielak, Marta; Brzozowska, Anna

    2011-12-01

    The present study was conducted to investigate whether hair calcium levels are related to nutritional habits, selected status parameters, and life-style factors in young women. Eighty-five healthy female students neither pregnant nor lactating, using no hair dyes or permanents were recruited for the study. Food consumption data, including fortified products and dietary supplements were collected with 4-day records. The calcium levels in hair and serum were analyzed by atomic absorption spectroscopy. Serum osteocalcin and the C-terminal telopeptide of type I collagen were assayed by ELISA. The women were divided into four groups according to their total vitamin D and calcium intakes and hair calcium levels. At adequate calcium intake and comparable serum bone biomarker levels, supplemental vitamin D increased the hair calcium levels. On the other hand, at lower than estimated adequate requirement of vitamin D intake the hair calcium levels were comparable in women with low calcium intakes but consuming high amounts of meat products or those whose diets were rich in dairy products, possibly due to homeostatic mechanisms. Elevated hair calcium was seen in 25% of subjects and could not be related to nutritional or life-style factors. The results show that the hair calcium levels were weakly related to the quality of diet, with some synergistic interactions between nutrients, especially vitamin D and magnesium.

  7. Developmental neurotoxicity of methylmercury: the role of microtubules

    SciTech Connect

    Sager, P.R.

    1982-01-01

    The purpose of this research was to investigate the interaction of methylmercury with microtubules as a possible mechanism for methylmercury-caused developmental neurotoxicity. Methylmercury effects on developing cerebellar cortex, an area of rapid proliferation, were examined. This model was used to test the hypothesis that microtubules of the mitotic spindle are sensitive to methylmercury in vivo as well as in cultured cells. The effect of methylmercury on non-spindle microtubules was studied in cultured cells. Cellular levels of methylmercury were determined and were used to construct a dose-response relationship. The direct effects of methylmercury on microtubule assembly in vitro were also documented. The data from these three systems have been integrated to form a hypothesis for the role of microtubules in developmental neurotoxicity caused by methylmercury. 159 references, 23 figures, 16 tables.

  8. Serum drug level-related sodium valproate-induced hair loss.

    PubMed

    Ramakrishnappa, Suresh K; Belhekar, Mahesh N

    2013-01-01

    Sodium valproate is a well-established treatment in epilepsy and mood disorders. Its utility is compromised by its adverse effects such as tremor, weight gain, hair loss, and liver dysfunction. Hair loss may occur when drug is used in higher dose. Drug-induced hair loss is diffused and non-scarring, which is reversible upon withdrawal. But there are no case reports showing relation between serum levels of valproate and occurrence of hair loss. So we took interest in reporting this case report.

  9. Temporal variation of blood and hair mercury levels in pregnancy in relation to fish consumption history in a population living along the St. Lawrence River.

    PubMed

    Morrissette, Joëlle; Takser, Larissa; St-Amour, Genevieve; Smargiassi, Audrey; Lafond, Julie; Mergler, Donna

    2004-07-01

    Fish consumption from the Great Lakes and the St. Lawrence River has been decreasing over the last years due to advisories and increased awareness of the presence of several contaminants. Methylmercury (MeHg), a well-established neurotoxicant even at low levels of exposure, bioaccumulates to differing degrees in various fish species and can have serious adverse effects on the development and functioning of the human central nervous system, especially during prenatal exposure. Most studies on MeHg exposure have focussed on high-level consumers from local fish sources, although mercury (Hg) is also present in fresh, frozen, and canned market fish. Moreover, little information exists on the temporal variation of blood and hair Hg in pregnant women, particularly in populations with low levels of Hg. The aim of the present study was to characterize the temporal variation of Hg during pregnancy and to investigate the relation between fish consumption from various sources prior to and during pregnancy and maternal cord blood and mother's hair Hg levels. We recruited 159 pregnant women from Southwest Quebec through two prenatal clinics of the Quebec Public Health System. All women completed two detailed questionnaires concerning their fish consumption (species and frequency) prior to and during pregnancy. The women also provided blood samples for all three trimesters of pregnancy and hair samples after delivery of up to 9 cm in length. Blood and hair Hg levels were analyzed by cold-vapor atomic-absorption and -fluorescence spectrometry methods, respectively. Results showed that maternal blood and hair Hg levels decreased significantly between the second and third trimesters of pregnancy. However, cord blood Hg was significantly higher than maternal blood at birth. Maternal hair was correlated with Hg blood concentration and was highly predictive of the organic fraction in cord blood. A strong dose relation was observed between the frequency of fish consumption before and

  10. Prenatal exposure to low-level methylmercury alters the child's fine motor skills at the age of 18 months.

    PubMed

    Prpić, Igor; Milardović, Ana; Vlašić-Cicvarić, Inge; Špiric, Zdravko; Radić Nišević, Jelena; Vukelić, Petar; Snoj Tratnik, Janja; Mazej, Darja; Horvat, Milena

    2017-01-01

    To compare motor, cognitive and language characteristics in children aged 18 months who were prenatally exposed to low-level methyl-mercury (MeHg), and to analyze the eventual differences in these characteristics in relation to cord blood THg concentration. The total number of 205 child-mother pairs was included in the study, and total cord blood mercury was measured in 198 of them. Out of the 198 already measured samples, 47 of them have also been tested for methyl-mercury in cord blood. Data regarding the 47 samples of MeHg levels has been used for calculating the correlation between cord blood THg and cord blood MeHg. MeHg and THg showed a significant correlation (r=0.95, p<0.05). One month after the delivery, mothers were asked to complete the questionnaire regarding socioeconomic factors, breastfeeding of their infants, and dietary habits during pregnancy. Neurodevelopmental assessment of motor, cognitive and language skills were conducted on 168 children using The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Regarding the cord blood THg concentration, 135 children were divided in 4 quartile groups. Their neurodevelopmental characteristics have been compared. The cord blood THg concentration median and inter-quartile range was 2.98ng/g (1.41-5.61ng/g). There was a negative correlation between cord blood THg concentration and fine motor skills (rho=-0.22, p=0.01). It is evident that children grouped in 2nd ,3rd and 4th quartile had statistically significant lower fine motor skills assessment related to those grouped in 1st quartile (2nd quartile -1.24, p=0.03; 3rd quartile -1.28, p=0.03; 4th quartile -1.45, p=0.01). The differences in fine motor skills assessments between children in 2nd and 3rd and 3rd and 4th quartile were not statistically significant. Intrauterine exposure to low-level THg (MeHg) is associated with alterations in fine motor skills at the age of 18 months. Copyright © 2016. Published by Elsevier Inc.

  11. Hair as a Meaningful Measure of Baseline Cortisol Levels over Time in Dogs

    PubMed Central

    Bryan, Heather M; Adams, Amanda G; Invik, Rosemary M; Wynne-Edwards, Katherine E; Smits, Judit EG

    2013-01-01

    Cortisol measurements of hair are becoming a valuable tool in monitoring chronic stress. To further validate this approach in domestic dogs, we compared the variability of cortisol immunoreactivity in hair with that in saliva and feces of dogs housed under constant social and physical conditions. Fecal (n = 268), and hair (n = 21) samples were collected over 3 mo from 7 dogs housed in a kennel and kept for training veterinary students in minimally invasive procedures. Salivary samples (n = 181) were collected 3 times daily twice weekly during the last month of the study. Hair and salivary samples were analyzed by enzyme immunoassay and feces by radioimmunoassay. HPLC coupled with tandem mass spectrometry was used to confirm the presence of cortisol in 3 hair samples. Variability of cortisol was compared across sample types by using repeated-measures ANOVA followed by paired t tests. Within dogs, cortisol immunoreactivity was less variable in hair than in saliva or feces. Averaged over time, the variability of fecal samples approached that of hair when feces were collected at least 4 times monthly. As predicted, the stable social and environmental condition of the dogs maintained repeatability over time and supported the hypothesis that data from hair samples reflect baseline cortisol levels. These findings indicate that determining cortisol immunoreactivity in hair is a more practical approach than is using samples of saliva or feces in monitoring the effects of long-term stressors such as social or physical environments and disease progression. PMID:23562104

  12. Methylmercury production in the marine water column

    NASA Astrophysics Data System (ADS)

    Topping, G.; Davies, I. M.

    1981-03-01

    Although the biosynthesis of methylmercury in sediments is well established1, this is not necessarily the exclusive natural source of methylmercury entering the marine food chain, particularly commercial fish and shellfish species for human consumption. An examination of mercury levels in freshwater fish2, collected from a lake with a history of industrial mercury contamination, suggested that levels in fish are controlled in part by mercury in suspension and it followed that methylation should occur in the water column. Although methylmercury is present in seawater in coastal areas receiving discharges of waste containing either inorganic mercury3 or methylmercury4 there is no evidence that methylmercury is actually formed in the water column. We now present data which demonstrate that inorganic mercury can be methylated in the water column and we compare this production with that known to occur in marine sediments.

  13. Human hair mercury levels in the Wanshan mercury mining area, Guizhou Province, China.

    PubMed

    Li, Ping; Feng, Xinbin; Qiu, Guangle; Shang, Lihai; Li, Guanghui

    2009-12-01

    The total mercury (T-Hg) and methyl mercury (Me-Hg) concentrations in the hair were measured to evaluate mercury (Hg) exposure for the residents in Da-shui-xi Village (DSX) and Xia-chang-xi Village (XCX) in the Wanshan Hg mining area, Guizhou Province, Southwestern China. The mean concentrations in the hair of DSX residents were 5.5 ± 2.7 μg/g and 1.9 ± 0.9 μg/g for T-Hg and Me-Hg, respectively. The concentrations in the hair of XCX residents were 3.3 ± 1.4 μg/g and 1.2 ± 0.5 μg/g for T-Hg and Me-Hg, respectively. Hair Me-Hg concentrations were significantly correlated to T-Hg (r = 0.42, P < 0.01) in the two sites; on average, hair Me-Hg concentration accounted for 40 and 44% of T-Hg for DSX and XCX residents, respectively. Age has no obvious correlation with hair Hg and the hair Hg levels showed a significant gender difference, with higher T-Hg and Me-Hg concentrations in the hair from males than females. The rice collected from the two sites showed high levels of T-Hg and Me-Hg concentration. The results indicated a certain Hg exposure for the residents in DSX and XCX in the Wanshan Hg mining area.

  14. High Methylmercury in Arctic and Subarctic Ponds is Related to Nutrient Levels in the Warming Eastern Canadian Arctic.

    PubMed

    MacMillan, Gwyneth A; Girard, Catherine; Chételat, John; Laurion, Isabelle; Amyot, Marc

    2015-07-07

    Permafrost thaw ponds are ubiquitous in the eastern Canadian Arctic, yet little information exists on their potential as sources of methylmercury (MeHg) to freshwaters. They are microbially active and conducive to methylation of inorganic mercury, and are also affected by Arctic warming. This multiyear study investigated thaw ponds in a discontinuous permafrost region in the Subarctic taiga (Kuujjuarapik-Whapmagoostui, QC) and a continuous permafrost region in the Arctic tundra (Bylot Island, NU). MeHg concentrations in thaw ponds were well above levels measured in most freshwater ecosystems in the Canadian Arctic (>0.1 ng L(-1)). On Bylot, ice-wedge trough ponds showed significantly higher MeHg (0.3-2.2 ng L(-1)) than polygonal ponds (0.1-0.3 ng L(-1)) or lakes (<0.1 ng L(-1)). High MeHg was measured in the bottom waters of Subarctic thaw ponds near Kuujjuarapik (0.1-3.1 ng L(-1)). High water MeHg concentrations in thaw ponds were strongly correlated with variables associated with high inputs of organic matter (DOC, a320, Fe), nutrients (TP, TN), and microbial activity (dissolved CO2 and CH4). Thawing permafrost due to Arctic warming will continue to release nutrients and organic carbon into these systems and increase ponding in some regions, likely stimulating higher water concentrations of MeHg. Greater hydrological connectivity from permafrost thawing may potentially increase transport of MeHg from thaw ponds to neighboring aquatic ecosystems.

  15. Impact of land use and physicochemical settings on aqueous methylmercury levels in the Mobile-Alabama River System.

    PubMed

    Bonzongo, Jean-Claude J; Lyons, W Berry

    2004-08-01

    Mercury (Hg) concentrations above levels that could pose health risks have been measured recently in predatory fish from many aquatic systems in the southeastern region of the United States. Based on hypotheses derived from published experimental data on the aqueous geochemistry of Hg, we investigated the effect of certain natural and human-imposed conditions on in situ levels of methylmercury (MeHg) in the Mobile-Alabama River System (MARS). Water samples were collected from different types of environments, hypothesized to have contrasting levels of MeHg in the aqueous phase, and were analyzed for total-Hg (THg) and MeHg concentrations, as well as some key geochemical parameters. The results showed the following. i) Overall, total Hg concentrations in waters of the MARS are quite uniformly distributed and vary from 0.2 to 6 ng L(-1), suggesting that besides geological sources, atmospheric deposition is certainly the main source of Hg inputs in the studied system. ii) In locations with comparable THg levels, the Hg fraction present as MeHg was consistently higher in samples collected from the Coastal Plain portion of the MARS as compared to those from other geological provinces. iii) Our in situ observations confirmed conclusions derived from laboratory experiments, in that, MeHg abundance in aquatic systems correlates with sulfate (but only within a narrow range of concentrations); decreasing pH; and has no direct relationships with either nitrate or phosphate. iv) The investigation of Hg accumulation in biota at a single site showed that an aquatic system with low THg concentrations but a high MeHg:THg ratios, could have organisms with Hg content above safe levels. Therefore, potential health risks to fish eating populations can exist even when the aqueous phase does not show signs of significant Hg enrichment.

  16. Water-level fluctuations influence sediment porewater chemistry and methylmercury production in a flood-control reservoir.

    PubMed

    Eckley, Chris S; Luxton, Todd P; Goetz, Jennifer; McKernan, John

    2017-03-01

    Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluctuations impact Hg cycling, particularly the formation of the more toxic and bioaccumulative methylmercury (MeHg). Total-Hg (THg), MeHg, stable isotope methylation rates and several ancillary parameters were measured in reservoir sediments (including some in porewater and overlying water) that are seasonally and permanently inundated. The results showed that sediment and porewater MeHg concentrations were over 3-times higher in areas experiencing water-level fluctuations compared to permanently inundated sediments. Analysis of the data suggest that the enhanced breakdown of organic matter in sediments experiencing water-level fluctuations has a two-fold effect on stimulating Hg methylation: 1) it increases the partitioning of inorganic Hg from the solid phase into the porewater phase (lower log Kd values) where it is more bioavailable for methylation; and 2) it increases dissolved organic carbon (DOC) in the porewater which can stimulate the microbial community that can methylate Hg. Sulfate concentrations and cycling were enhanced in the seasonally inundated sediments and may have also contributed to increased MeHg production. Overall, our results suggest that reservoir management actions can have an impact on the sediment-porewater characteristics that affect MeHg production. Such findings are also relevant to natural water systems that experience wetting and drying cycles, such as floodplains and ombrotrophic wetlands.

  17. Neurotoxicity of methylmercury in the pigeon

    SciTech Connect

    Evans, H.L.; Garman, R.H.; Laties, V.G.

    1982-11-01

    Pigeons repeatedly exposed to sublethal doses of methylmercury (5-10 mg Hg/kg/wk, po, for 34-77 days) exhibited marked behavioral changes that were accompanied by only minor evidence of neuropathologic changes at the light microscopic level. Accuracy and rate of pecking for grain declined while food intake remained unchanged. Methylmercury produced permanent changes in posture and in motor coordination. The regional distribution of methylmercury within the nervous system was poorly correlated with the distribution of pathologic changes. Overt behavioral signs appeared after the brain accumulated more than about 12 to 16 ppm Hg. Data with pigeons support earlier evidence that the dose-response function for methylmercury is modulated by dose rate and duration of exposure, since the pattern of blood and tissue distribution of Hg is established in advance of the appearance of signs. The pigeon is more sensitive to methylmercury than are mice and rats, but less sensitive than primates.

  18. Methylmercury in water samples at the pg/L level by online preconcentration liquid chromatography cold vapor-atomic fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Brombach, Christoph-Cornelius; Chen, Bin; Corns, Warren T.; Feldmann, Jörg; Krupp, Eva M.

    2015-03-01

    Ultra-traces of methylmercury at the sub-ppt level can be magnified in the foodweb and is of concern. In environmental monitoring a routine robust analytical method is needed to determine methylmercury in water. The development of an analytical method for ultra-trace speciation analysis of methylmercury (MeHg) in water samples is described. The approach is based on HPLC-CV-AFS with on-line preconcentration of water samples up to 200 mL, resulting in a detection limit of 40 pg/L (ppq) for MeHg, expressed as Hg. The unit consists of an optimized preconcentration column filled with a sulfur-based sorption material, on which mercury species are preconcentrated and subsequently eluted, separated and detected via HPLC-CV-AFS (high performance liquid chromatography-cold vapor atomic fluorescence spectrometry). During the method development a type of adsorbate material, the pH dependence, the sample load rate and the carry-over were investigated using breakthrough experiments. The method shows broad pH stability in the range of pH 0 to 7, without the need for buffer addition and shows limited matrix effects so that MeHg is quantitatively recovered from sewage, river and seawater directly in the acidified samples without sample preparation.

  19. Negative regulation of Shh levels by Kras and Fgfr2 during hair follicle development.

    PubMed

    Mukhopadhyay, Anandaroop; Krishnaswami, Suguna Rani; Cowing-Zitron, Christopher; Hung, Nai-Jung; Reilly-Rhoten, Heather; Burns, Julianne; Yu, Benjamin D

    2013-01-15

    Activating mutations in the KRAS oncogene are associated with three related human syndromes, which vary in hair and skin phenotypes depending on the involved allele. How variations in RAS signals are interpreted during hair and skin development is unknown. In this study, we investigated the developmental and transcriptional response of skin and hair to changes in RAS activity, using mouse genetic models and microarray analysis. While activation of Kras (Kras(G12D)) in the skin had strong effects on hair growth and hair shape, steady state changes in downstream RAS/MAPK effectors were subtle and detected only by transcriptional responses. To model the transcriptional response of multiple developmental pathways to active RAS, the effects of growth factor stimulation were studied in skin explants. Here FGF acutely suppressed Shh transcription within 90 min but had significantly less effect on Eda, WNT, Notch or BMP pathways. Furthermore, in vivo Fgfr2 loss-of-function in the ectoderm caused derepression of Shh, revealing a role for FGF in Shh regulation in the hair follicle. These studies define both dosage sensitive effects of RAS signaling on hair morphogenesis and reveal acute mechanisms for fine-tuning Shh levels in the hair follicle. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. New Evidence on Variations of Human Body Burden of Methylmercury from Fish Consumption

    PubMed Central

    Canuel, René; de Grosbois, Sylvie Boucher; Atikessé, Laura; Lucotte, Marc; Arp, Paul; Ritchie, Charles; Mergler, Donna; Chan, Hing Man; Amyot, Marc; Anderson, Robin

    2006-01-01

    Epidemiologic studies commonly use mercury (Hg) level in hair as a valid proxy to estimate human exposure to methylmercury (MeHg) through fish consumption. This study presents the results yielded by a complete data set on fish consumption habits, Hg levels in edible fish resources, and corresponding Hg accumulation in hair, gathered in three distinct communities of eastern Canada. For one of these communities, the average hair Hg concentration was 14 times less than the expected value based on calculated daily oral exposure and current knowledge of MeHg metabolism. This finding could be explained by differences in specific genetic characteristics and/or interactive effects of other dietary components. PMID:16451872

  1. Serum and hair zinc levels in breast cancer: a meta-analysis

    PubMed Central

    Wu, Xiujuan; Tang, Jing; Xie, Mingjun

    2015-01-01

    Many studies have investigated the association between serum/hair zinc levels and breast cancer, but the results were inconsistent. To compare the serum and hair zinc levels in women with breast cancer and controls, we conducted a systematic literature search of PubMed, Web of Science, Cochrane Library and Embase to identify relevant studies with publication dates up through November 2014. Based on a random effects model, summary standard mean differences (SMDs) and the corresponding 95% confidence intervals (CIs) were used to compare the serum and hair zinc levels in women with breast cancer and controls. Fourteen studies that investigated serum zinc levels and seven studies that assessed hair zinc levels were included. Our study observed no difference in serum zinc levels between breast cancer cases and controls (SMD (95%CI): −0.65[−1.42,0.13]). However, we determined that hair zinc levels were lower in women with breast cancer compared with those of controls (SMD (95%CI): −1.99[−3.46, −0.52]). In conclusion, this study was the first to provide evidence that hair zinc levels in female breast cancer patients are lower than in controls; however, there was no significant difference in serum zinc levels between female breast cancer patients and controls. PMID:26179508

  2. Hair Zinc Level Analysis and Correlative Micronutrients in Children Presenting with Malnutrition and Poor Growth

    PubMed Central

    Han, Tae Hwan; Lee, Jin

    2016-01-01

    Purpose Zinc deficiency can induce serious clinical problems in the gastrointestinal (GI) system and immune system and can affect growth and development. It is more severe in younger patients. Chronic zinc deficiency is reflected more precisely in hair than in serum. We studied hair zinc levels and other hair and serum micronutrients in chronic malnourished children to identify which micronutrients are affected or correlated with the other ones. Methods Hair mineral analyses were performed in 56 children (age, 1-15 years) presenting with malnutrition, poor growth, poor appetite, anorexia, with/without other GI symptoms (diarrhea, abdominal pain, constipation) from August 2012 to March 2015. Biochemical studies for macronutrients and major micronutrients were also conducted. Results Hair zinc deficiency was diagnosed in 88%, and serum zinc deficiency was diagnosed in 55% of the children. There was no statistical correlation between serum and tissue zinc level. Hair zinc levels were highly correlated with serum vitamin D (r=−0.479, p=0.001), which also showed correlation with hair levels of magnesium and calcium. (r=0.564, 0.339, p=0.001, 0.011). Hair calcium level was correlated with serum pre-albumin (r=0.423, p=0.001). These correlations may explain the phenomenon that the major clinical manifestation of zinc deficiency is poor body growth. Clinical symptoms were resolved in most children after zinc supplementation. Conclusion Hair zinc and mineral analyses are useful as a therapeutic guide in the clinical investigation of children with malnutrition and poor growth. PMID:28090471

  3. Methylmercury Poisoning in Iraq

    ERIC Educational Resources Information Center

    Bakir, F.; And Others

    1973-01-01

    Discusses incidence of methylmercury poisoning throughout the world with increasing industrial and agricultural use of mercury compounds. Describes recent epidemic in Iraq resulting from use of wheat treated with methylmercurial fungicide. New data are presented on the toxicity of methylmercury and its metabolic fate in the human body. (JR)

  4. Methylmercury Poisoning in Iraq

    ERIC Educational Resources Information Center

    Bakir, F.; And Others

    1973-01-01

    Discusses incidence of methylmercury poisoning throughout the world with increasing industrial and agricultural use of mercury compounds. Describes recent epidemic in Iraq resulting from use of wheat treated with methylmercurial fungicide. New data are presented on the toxicity of methylmercury and its metabolic fate in the human body. (JR)

  5. Elevated iron levels in hair from steel mill workers in Karachi, Pakistan

    SciTech Connect

    Jamall, I.S.; Jaffer, R.A.

    1987-10-01

    Over the last two decades, much interest has been focused on the use of trace metals in human hair to diagnose nutritional deficiencies of these metals or toxicities of metals such as lead or organic mercury. Although the diagnostic value of zinc (Zn), copper (Cu), lead and mercury levels in human hair have been well established, little information is available on the significance of iron (Fe) levels in hair to diagnose nutritional deficiency or toxicity of this metal. The present study was conducted to determine if occupational exposure in the steel industry resulted in alterations i the levels of Fe, Zn, and Cu in hair and could thus serve as a simple tool for monitoring exposure to potentially hazardous levels of these metals.

  6. Hair shaft miRNA-221 levels as a new tumor marker of malignant melanoma.

    PubMed

    Inada, Taisuke; Fukushima, Satoshi; Murai, Masayuki; Jinnin, Masatoshi; Miyashita, Azusa; Nakahara, Satoshi; Yamashita, Junji; Aoi, Jun; Masuguchi, Shinichi; Ihn, Hironobu

    2015-02-01

    miRNA-221 (miR-221) is known to be abnormally expressed in many human cancers. The serum levels of miR-221 have been reported as a tumor marker for malignant melanoma (MM). We hypothesized that the hair shaft miR-221 levels may be increased in patients with MM. We therefore assessed the possibility that hair shaft miR-221 levels could be a marker for MM. The hair shaft miR-221 levels were significantly higher in patients with MM than controls. The rates of increased hair shaft miR-221 levels above the cut-off value were comparable to those of serum 5-S-CD, which is a tumor marker commonly used for MM. Measurements of the hair shaft miR-221 levels could have potential clinical value in the detection of MM. This is the first report investigating the hair shaft levels of an miRNA in patients with MM. Our investigations offer new insight into the relationship between miR-221 and MM, and may provide a new, non-invasive way to screen for melanoma.

  7. Cortisol levels in hair reflect behavioural reactivity of dogs to acoustic stimuli.

    PubMed

    Siniscalchi, M; McFarlane, J R; Kauter, K G; Quaranta, A; Rogers, L J

    2013-02-01

    Cortisol levels in hair samples were examined in fourteen domestic dogs and related to the dogs' responses to different acoustic stimuli. Stimuli were playbacks of species-typical vocalizations recorded during three different situations ("disturbance", "isolation" and "play" barks) and the sounds of a thunderstorm. Hair samples were collected at 9:00 h and 17:00 h two weeks after the behavioural tests. Results showed that behavioural reactivity to playback of the various stimuli correlates with cortisol levels in hair samples collected at 9:00 h, and the same was the case for the separate measures of behaviour (i.e. hiding, running away, seeking attention from the tester, panting and lowering of the body posture). Hence, levels of cortisol in hair appear to reflect the dog's chronic state of emotional reactivity, or temperament.

  8. Influence of Reservoir Water Level Fluctuations on Sediment Methylmercury Concentrations Downstream of the Historical Black Butte Mercury Mine, OR

    EPA Science Inventory

    Mercury (Hg) is a pollutant of global concern due to its ability to accumulate as methylmercury (MeHg) in biota. Mercury is methylated by anaerobic microorganisms such as sulfate reducing bacteria (SRB) in water and sediment. Throughout North America, reservoirs tend to have e...

  9. Influence of Reservoir Water Level Fluctuations on Sediment Methylmercury Concentrations Downstream of the Historical Black Butte Mercury Mine, OR

    EPA Science Inventory

    Mercury (Hg) is a pollutant of global concern due to its ability to accumulate as methylmercury (MeHg) in biota. Mercury is methylated by anaerobic microorganisms such as sulfate reducing bacteria (SRB) in water and sediment. Throughout North America, reservoirs tend to have e...

  10. Association Between Human Hair Loss and the Expression Levels of Nucleolin, Nucleophosmin, and UBTF Genes.

    PubMed

    Tasdemir, Sener; Eroz, Recep; Dogan, Hasan; Erdem, Haktan Bagis; Sahin, Ibrahim; Kara, Murat; Engin, Ragip Ismail; Turkez, Hasan

    2016-04-01

    Nucleolar organizer regions, also known as argyrophilic nucleolar organizer regions, are associated with ribosomal genes. The main function of the nucleolus is the rapid production of ribosomal subunits, a process that must be highly regulated to provide the appropriate levels for cellular proliferation and cell growth. There are no studies in the literature addressing the expression and function of nucleolar component proteins, including nucleophosmin, nucleolin and the upstream binding transcription factor (UBTF), in human follicular hair cells. Nineteen healthy males who had normal and sufficient hair follicles on the back of the head, but exhibited hair loss on the frontal/vertex portions of the head and 14 healthy males without hair loss were included in the current study. Gene expression levels were measured by relative quantitative real time polymerase chain reaction. In the individuals suffering from alopecia, the total expression levels of nucleolin, nucleophosmin, and UBTF were lower in normal sites than in hair loss sites. Strong expression level correlations were detected between: nucleophosmin and nucleolin; nucleophosmin and UBTF, and nucleolin and UBTF for both groups. There was an association between human hair loss and the expression levels of nucleolin, nucleophosmin, and UBTF genes.

  11. Low-level laser (light) therapy (LLLT) for treatment of hair loss.

    PubMed

    Avci, Pinar; Gupta, Gaurav K; Clark, Jason; Wikonkal, Norbert; Hamblin, Michael R

    2014-02-01

    Alopecia is a common disorder affecting more than half of the population worldwide. Androgenetic alopecia, the most common type, affects 50% of males over the age of 40 and 75% of females over 65. Only two drugs have been approved so far (minoxidil and finasteride) and hair transplant is the other treatment alternative. This review surveys the evidence for low-level laser therapy (LLLT) applied to the scalp as a treatment for hair loss and discusses possible mechanisms of actions. Searches of PubMed and Google Scholar were carried out using keywords alopecia, hair loss, LLLT, photobiomodulation. Studies have shown that LLLT stimulated hair growth in mice subjected to chemotherapy-induced alopecia and also in alopecia areata. Controlled clinical trials demonstrated that LLLT stimulated hair growth in both men and women. Among various mechanisms, the main mechanism is hypothesized to be stimulation of epidermal stem cells in the hair follicle bulge and shifting the follicles into anagen phase. LLLT for hair growth in both men and women appears to be both safe and effective. The optimum wavelength, coherence and dosimetric parameters remain to be determined. © 2013 Wiley Periodicals, Inc.

  12. Expansion of methylmercury poisoning outside of Minamata: an epidemiological study on chronic methylmercury poisoning outside of Minamata.

    PubMed

    Ninomiya, T; Ohmori, H; Hashimoto, K; Tsuruta, K; Ekino, S

    1995-07-01

    The first methylmercury poisoning by consumption of fish arose in Minamata, Japan, in 1953. Methylmercury dispersed from Minamata to the Shiranui Sea until 1968. Mercury concentration in the hair of residents on the coast of the Shiranui Sea was 10 to 20 times higher than that in nonpolluted people in Kumamoto Prefecture in 1960. People on the coast of the Shiranui Sea have consumed fish containing low-dose methylmercury without a ban over decades until 1968. We studied the effect of long-term consumption of methylmercury on those people 10 years later after the end of methylmercury dispersion. Our epidemiological study clarified that people in a fishing village (Ooura) on the coast of the Shiranui Sea showed a significantly higher frequency of neurological signs characteristic of methylmercury poisoning (hypoesthesia, ataxia, impairment of hearing, visual change, and dysarthria) in comparison with people in a nonpolluted fishing village (Ichiburi). The neurological disorders were still detected 10 years later in Ooura after the end of methylmercury dispersion from Minamata; hypoesthesia showed the highest frequency in Ooura. These results suggest that people on the coast of the Shiranui Sea were afected by long-term dietary exposure to methylmercury.

  13. Expansion of methylmercury poisoning outside of Minamata: An epidemiological study on chronic methylmercury poisoning outside of Minamata

    SciTech Connect

    Ninomiya, Tadashi; Ohmori, Hiroyuki; Hashimoto, Kiyomi

    1995-07-01

    The first methylmercury poisoning by consumption of fish arose in Minamata, Japan, in 1953. Methylmercury dispersed from Minamata to the to the Shiranui Sea until 1968. Mercury concentration in the hair of residents on the coast of the Shiranui Sea was 10 to 20 times higher than in nonpolluted people in Kumamoto Prefecture in 1960. People on the coast of the Shiranui Sea have consumed fish containing low-dose methylmercury without a ban over decades until 1968. We studied the effect of long-term consumption of methylmercury on those people 10 years later after the end of methylmercury dispersion. Our epidemiological study clarified that people in a fishing village (Ooura) on the coast of the Shiranui Sea showed a significantly higher frequency of neurological signs characteristics of methylmercury poisoning (hypoesthesia, ataxia, impairment of hearing, visual change, and dysarthria) in comparison with people in a nonpolluted fishing village (Ichiburi). The neurological disorders were still detected 10 years later in Ooura after the end of methylmercury dispersion from Minamata: hypoesthesia showed the highest frequency in Ooura. These results suggest that people on the coast of the Shiranui Sea were affected by long-term dietary exposure to methylmercury. 14 refs., 1 fig., 1 tab.

  14. Protease Inhibitor Levels in Hair Samples Strongly Predict Virologic Responses to HIV Treatment

    PubMed Central

    Gandhi, Monica; Ameli, Niloufar; Bacchetti, Peter; Gange, Stephen J.; Anastos, Kathryn; Levine, Alexandra; Hyman, Charles L.; Cohen, Mardge; Young, Mary; Huang, Yong; Greenblatt, Ruth M.

    2009-01-01

    Objective Antiretroviral (ARV) therapies fail when behavioral or biologic factors lead to inadequate medication exposure. Currently available methods to assess ARV exposure are limited. Levels of ARVs in hair reflect plasma concentrations over weeks to months and may provide a novel method for predicting therapeutic responses. Design/methods The Women's Interagency HIV Study, a prospective cohort of HIV-infected women, provided the basis for developing and assessing methods to measure commonly-prescribed protease inhibitors (PIs) - lopinavir (LPV) and atazanavir (ATV) - in small hair samples. We examined the association between hair PI levels and initial virologic responses to therapy in multivariate logistic regression models. Results ARV concentrations in hair were strongly and independently associated with treatment response for 224 women starting a new PI-based regimen. For participants initiating LPV/RTV, the odds ratio (OR) for virologic suppression was 39.8 (95%CI 2.8–564) for those with LPV hair levels in the top tertile (>1.9ng/mg) compared to the bottom (≤0.41ng/mg) when controlling for self-reported adherence, age, race, starting viral load and CD4, and prior PI experience. For women starting ATV, the adjusted OR for virologic success was 7.7 (95%CI 2.0-29.7) for those with hair concentrations in the top tertile (>3.4ng/mg) compared to the lowest (≤1.2ng/mg). Conclusions PI levels in small hair samples were the strongest independent predictor of virologic success in a diverse group of HIV-infected adults. This noninvasive method for determining ARV exposure may have particular relevance for the epidemic in resource-poor settings due to the ease of collecting and storing hair. PMID:19165084

  15. The use of low-level light for hair growth: part I.

    PubMed

    Avram, Marc R; Rogers, Nicole E

    2009-06-01

    Low-level laser therapy (LLLT) is a new therapy for the treatment of hair loss. It has received enormous media attention and tremendous marketing budgets from companies that sell the devices, but no independent, peer-reviewed studies have demonstrated its efficacy in this application. Here we investigate the efficacy of LLLT in enhancing hair growth. A total of seven patients were exposed to LLLT twice weekly for 20 minutes each time over a period of 3-6 months. Five patients were treated for a total of 3 months and two were treated for 6 months. Videomicroscopic images were taken at baseline, 3 months, and 6 months, and analyzed for changes in vellus hair counts, terminal hair counts, and shaft diameter. Both videomicroscopic and global images underwent blinded review for evidence of subjective improvement. Patients also answered questionnaires assessing hair growth throughout the study. Neither patients nor physicians conducting the study received any financial compensation. The results indicate that on average patients had a decrease in the number of vellus hairs, an increase in the number of terminal hairs, and an increase in shaft diameter. However, paired i-testing indicated that none of these changes was statistically significant. Also, blinded evaluation of global images did not support an improvement in hair density or caliber. LLLT may be a promising treatment option for patients who do not respond to either finasteride or minoxidil, and who do not want to undergo hair transplantation. This technology appears to work better for some people than for others. Factors predicting who will most benefit are yet to be determined. Larger, longer-term placebo-controlled studies are needed to confirm these findings, and demonstrate statistical significance, or refute them altogether.

  16. Hair mercury levels in pregnant women in Mahshahr, Iran: fish consumption as a determinant of exposure.

    PubMed

    Salehi, Zohreh; Esmaili-Sari, Abbas

    2010-09-15

    MeHg is a well-documented neurotoxicant even at low levels of exposure. Developing brain, in particular, is vulnerable to that. Through bioaccumulating to differing degrees in various fish species, it can have serious adverse effects on the development and functioning of the human central nervous system, especially during prenatal exposure. Therefore, the purpose of this study was to investigate mercury concentration in hair samples of pregnant women living in Mahshahr located in Khuzestan province, Iran. It assessed the association between fish consumption and specific characteristics that can influence exposure. From April to June 2008, 149 pregnant women were invited to participate in this study. An interview administered questionnaire was used to collect information about age, body weight, height, fish (fresh, canned and shrimp) consumption, pregnancy stage, residence duration, education level, family income and number of dental amalgam fillings. The obtained results showed that the geometric mean and range for hair total Hg concentration was 3.52 microg/g (0.44-53.56 microg/g). About 5.4% of mothers had hair total Hg levels in excess of 10 microg/g. Maternal hair mercury level was less than threshold level of WHO (5 microg/g). As expected, there was a clear increase in hair Hg with reported fresh marine fish consumption (p=0.04). The highest mean for hair mercury level in a group who consumed fish several times per week, was 4.93 microg/g. Moreover, a significant effect of age and residential time on Hg concentration in the hair of the women was found. Pregnant women in Mahshahr consumed large amounts of fish; consequently, most of their offspring were prenatally exposed to moderately high levels of mercury. The results found suggest that pregnant women should decrease their fish consumption.

  17. Hormone levels in neonatal hair reflect prior maternal stress exposure during pregnancy.

    PubMed

    Kapoor, Amita; Lubach, Gabriele R; Ziegler, Toni E; Coe, Christopher L

    2016-04-01

    Hormones present in hair provide summative information about endocrine activity while the hair was growing. Therefore, it can be collected from an infant after birth and still provide retrospective information about hormone exposure during prenatal development. We employed this approach to determine whether a delimited period of maternal stress during pregnancy affected the concentrations of glucocorticoids and gonadal hormones in the hair of neonatal rhesus monkeys. Hair from 22 infant monkeys exposed to 5 weeks of gestational disturbance was compared to specimens from 13 infants from undisturbed control pregnancies. Using an LC/MS/MS based technique, which permitted seven steroid hormones to be quantified simultaneously, we found 2 hormones were significantly different in infants from disturbed pregnancies. Cortisol and testosterone levels were lower in the hair of both male and female neonates. Maternal hair hormone levels collected on the same day after delivery no longer showed effects of the disturbance earlier during pregnancy. This study documents that a period of acute stress, lasting for 20% of gestation, has sustained effects on the hormones to which a developing fetus is exposed.

  18. Hormone levels in neonatal hair reflect prior maternal stress exposure during pregnancy

    PubMed Central

    Kapoor, Amita; Lubach, Gabriele R.; Ziegler, Toni E.; Coe, Christopher L.

    2016-01-01

    Hormones present in hair provide summative information about endocrine activity while the hair was growing. Therefore, it can be collected from an infant after birth and still provide retrospective information about hormone exposure during prenatal development. We employed this approach to determine whether a delimited period of maternal stress during pregnancy affected the concentrations of glucocorticoids and gonadal hormones in the hair of neonatal rhesus monkeys. Hair from 22 infant monkeys exposed to 5 weeks of gestational disturbance was compared to specimens from 13 infants from undisturbed control pregnancies. Using an LC/MS/MS based technique, which permitted seven steroid hormones to be quantified simultaneously, we found 2 hormones were significantly different in infants from disturbed pregnancies. Cortisol and testosterone levels were lower in the hair of both male and female neonates. Maternal hair hormone levels collected on the same day after delivery no longer showed effects of the disturbance earlier during pregnancy. This study documents that a period of acute stress, lasting for 20% of gestation, has sustained effects on the hormones to which a developing fetus is exposed. PMID:26802598

  19. Assessment of arsenic level in the hair of the nonoccupational Egyptian population: pilot study.

    PubMed

    Saad, A; Hassanien, M A

    2001-12-01

    Arsenic level of hair samples of apparently healthy Egyptian was measured by means of hydride atomic absorption spectrophotometery. It ranged between 0.04 and 1.04 mg As/kg hair, about 55% of the analysed hair samples were within the range of allowable values (0.08-0.25 mg As/kg hair), but 45% were not. There were no considerable sex-related differences (0.303 and 0.292 mg As/kg hair for males and females, respectively). Different educational levels did not influence it either, when the effect of the age had been excluded. Children and adolescents proved to be more susceptible to arsenic as their mean levels (0.353 microg/g), and were significantly higher than those in the adults (0.233 microg/g). Smoking and some dietary habits had an important role in the elevation of arsenic levels among the nonoccupational Egyptian population: 60% of smokers and 66.7% of indoor passive smokers had arsenic levels >0.25 mg As/kg hair. Arsenic levels were also dependent on the kind of smoking, as hair arsenic of the subject smoking molasses tobacco was found to be significantly higher than that of cigarette smokers (0.459 and 0.209 mg As/kg hair, respectively). The frequency of meat and fish consumption per week was also found to be positively, significantly correlated with arsenic levels. On the other hand, the frequency of consumption of fruits, fresh and cooked vegetables, milk and milk products per week beneficially influenced the arsenic level of the hair samples examined. Arsenic content of the consumed water in Egypt was 0.001 mg/l, which is below the maximum drinking water level allowed by World Health Organisation (WHO). Therefore, the arsenic content of domestic tap water hardly contributed to the arsenic exposure of the Egyptian population in the regions of the study. It is likely that exposure routes by smoking, fish and animal protein consumption are the principal cause of arsenic accumulation in the general Egyptian population.

  20. Strong Relationship between Oral Dose and Tenofovir Hair Levels in a Randomized Trial: Hair as a Potential Adherence Measure for Pre-Exposure Prophylaxis (PrEP)

    PubMed Central

    Liu, Albert Y.; Yang, Qiyun; Huang, Yong; Bacchetti, Peter; Anderson, Peter L.; Jin, Chengshi; Goggin, Kathy; Stojanovski, Kristefer; Grant, Robert; Buchbinder, Susan P.; Greenblatt, Ruth M.; Gandhi, Monica

    2014-01-01

    Background Pre-exposure prophylaxis (PrEP) trials using tenofovir-based regimens have demonstrated that high levels of adherence are required to evaluate efficacy; the incorporation of objective biomarkers of adherence in trial design has been essential to interpretation, given the inaccuracy of self-report. Antiretroviral measurements in scalp hair have been useful as a marker of long-term exposure in the HIV treatment setting, and hair samples are relatively easy and inexpensive to collect, transport, and store for analysis. To evaluate the relationship between dose and tenofovir concentrations in hair, we examined the dose proportionality of tenofovir in hair in healthy, HIV-uninfected adults. Methods A phase I, crossover pharmacokinetic study was performed in 24 HIV-negative adults receiving directly-observed oral tenofovir tablets administered 2, 4, and 7 doses/week for 6 weeks, with a ≥3-week break between periods. Small samples of hair were collected after each six-week period and analyzed for tenofovir concentrations. Geometric-mean-ratios compared levels between each pair of dosing conditions. Intensive plasma pharmacokinetic studies were performed during the daily-dosing period to calculate areas-under-the-time-concentration curves (AUCs). Results Over 90% of doses were observed per protocol. Median tenofovir concentrations in hair increased monotonically with dose. A log-linear relationship was seen between dose and hair levels, with an estimated 76% (95% CI 60–93%) increase in hair level per 2-fold dose increase. Tenofovir plasma AUCs modestly predicted drug concentrations in hair. Conclusions This study found a strong linear relationship between frequency of dosing and tenofovir levels in scalp hair. The analysis of quantitative drug levels in hair has the potential to improve adherence measurement in the PrEP field and may be helpful in determining exposure thresholds for protection and explaining failures in PrEP trials. Hair measures for

  1. Human milk as a source of methylmercury exposure in infants

    SciTech Connect

    Grandjean, P. ); Jorgensen, P.J. ); Weihe, P. )

    1994-01-01

    As methylmercury is excreted in human milk and infants are particularly susceptible to toxicity due to this compound, the purpose of this study was to evaluate the possible transfer of methylmercury to infants via breast-feeding. In a community with a high intake of seafood, 583 children from a birth cohort were followed. The duration of nursing was recorded, and hair samples were obtained for mercury analysis at approximately 12 months of age. The hair mercury concentrations increased with the length of the nursing period, and those nursed throughout the first year showed the highest geometric mean (9.0 nmol/g or 1.8 [mu]g/g). Human milk therefore seems to be an important source of methylmercury exposure in infants. As increasing time interval from weaning to hair sample collection was not associated with any detectable decrease in mercury concentrations. A slow or absent elimination of methylmercury during the first year after birth could explain this finding. In certain fishing communities, infants nursed for long periods may be at increased risk of developing methylmercury toxicity. 25 refs., 2 figs., 3 tabs.

  2. Human Milk as a Source of Methylmercury Exposure in Infants.

    PubMed Central

    Grandjean, P; Jørgensen, PJ; Weihe, P

    1994-01-01

    As methylmercury is excreted in human milk and infants are particularly susceptible to toxicity due to this compound, the purpose of this study was to evaluate the possible transfer of methylmercury to infants via breast-feeding. In a community with a high intake of seafood, 583 children from a birth cohort were followed. The duration of nursing was recorded, and hair samples were obtained for mercury analysis at approximately 12 months of age. The hair mercury concentrations increased with the length of the nursing period, and those nursed throughout the first year showed the highest geometric mean (9.0 nmol/g or 1.8 microg/g). Human milk therefore seems to be an important source of methylmercury exposure in infants. An increasing time interval from weaning to hair sample collection was not associated with any detectable decrease in mercury concentrations. A slow or absent elimination of methylmercury during the first year after birth could explain this finding. In certain fishing communities, infants nursed for long periods may be at increased risk of developing methylmercury toxicity. Images p74-a Figure 1. Figure 2. PMID:9719671

  3. Hair cadmium level of smoker and non-smoker human volunteers in and around Calcutta City

    SciTech Connect

    Chattopadhyay, P.K.; Samaddar, K.R. ); Joshi, H.C. )

    1990-08-01

    In recent years considerable interest has arisen concerning cadmium accumulation in man. In general, the body burden of cadmium of an urban population is due to occupational exposure, as well as non-occupational contamination. Several reports indicate that cadmium body burden of cigarette smokers or tobacco users is more than of non-smokers. Measurement of cadmium in human hair has been suggested as an indicator of body burden. Most industrialized countries have regular monitoring programs for measuring cadmium accumulation in humans. There has been little or no work done thus far in India regarding the level of cadmium in humans. The objective of this investigation was to survey the levels of cadmium in hair of random samples of human volunteers. The influences of smoking habits, urban or rural life and age of the volunteers on the level of cadmium in hair were examined.

  4. Trace element levels in hair of eight-year-old children.

    PubMed

    Herber, R F; Wibowo, A A; Das, H A; Egger, R J; van Deyck, W; Zielhuis, R L

    1983-01-01

    A study of trace element levels in hair was performed on 183 eight-year-old schoolchildren living in Bijlmermeer, a suburb of Amsterdam, the Netherlands. Microlevel-elements, such as Au, Co, Ag, Se and Cd, and macrolevel-elements, such as Pb, Cu, Fe and Zn, were analyzed using the NAA and AAS methods. The total group of children was divided into subgroups, according to ethnic origins: Caucasian boys and girls, Hindustani children and a Surinamese rest group. The relation between element levels in hair and nutritional status, anthropometric and haematological variables were studied. Most levels corresponded reasonably with literature data. The iron in hair may be positively related to daily dietary intake of iron.

  5. Hair Selenium Levels of School Children in Kashin-Beck Disease Endemic Areas in Tibet, China.

    PubMed

    Chen, Zhuo; Li, Hairong; Yang, Linsheng; Wang, Wuyi; Li, Yonghua; Gong, Hongqiang; Guo, Min; Nima, Cangjue; Zhao, Shengcheng; Wang, Jing; Ye, Bixiong; Danzeng, Sangbu; Deji, Yangzong

    2015-11-01

    Previous studies have shown that the selenium (Se) deficiency is an important factor for the etiology of Kashin-Beck disease (KBD). Although KBD is presently controlled in most regions of China, it is still active in the Tibetan Plateau. The present study aimed to assess the nutritional status of selenium in school children by using the Se level in hair as a biomarker in KBD endemic areas of Lhasa in Tibet, China. Hair samples of 155 school children aged 6-15 years were collected in both KBD areas and non-KBD areas of Lhasa in 2013. The Se level in the hair samples was determined by inductive coupled plasma mass spectrometry (ICP-MS). The average concentration of Se in children's hair was 0.232 μg/g in KBD areas of Lhasa, which was significantly higher than the data reported decades ago. A significant difference in hair Se was observed between the boys (0.255 μg/g) and the girls (0.222 μg/g) in the studied KBD areas (P < 0.01, Mann-Whitney U test), but hair Se did not vary by age or region. School children in KBD endemic areas in Lhasa likely have improved Se status as a result of high Se content staple food substitution with the enforcement of Free Education Policy and Nutrition Improvement Plan in Tibet. Nevertheless, there were still 20.3 % of students with low Se status (hair Se <0.20 μg/g), which showed that Se status of school children was also partly affected by low Se environment in KBD endemic areas of Lhasa.

  6. Ethyl Glucuronide Elimination Kinetics in Fingernails and Comparison to Levels in Hair.

    PubMed

    Fosen, Jan Toralf; Morini, Luca; Sempio, Cristina; Giarratana, Nefele; Enger, Asle; Mørland, Jørg; Høiseth, Gudrun

    2017-09-01

    Measurement of ethyl glucuronide (EtG) in nail, as a biomarker for alcohol intake, has recently been suggested as alternative to measurement in hair. The aim of this study was to compare levels of EtG in nail and hair, and to investigate the elimination kinetics of EtG in fingernails during an alcohol abstinent period. Overall, 40 subjects (median estimated daily intake of ethanol (EDI) 92.5 g/day) were recruited from an alcohol rehabilitation clinic. Nail and hair samples were collected at inclusion and nail clippings were collected every 7-10th day for up to 12 weeks. All patients showed higher nail EtG/EDI ratios compared to hair EtG/EDI ratios (P < 0.001). The median value of the ratios between EtG in nail and EtG in hair was 5.0 (range: 1.07-56.1). There was a significant correlation between nail EtG/EDI and hair EtG/EDI (Spearman's ρ = 0.638, P < 0.001). EtG disappeared from nails after ~2 months of abstinence and the median calculated EtG half-life in nail clippings was 13.3 days (range: 5.5-29.0). There was a significant correlation between the time elapsed to last positive sample for nail EtG and nail EtG levels at time of inclusion (Spearman's ρ = 0.449, P = 0.004). The present data indicate that EtG cut-off levels in nails should be higher compared to the established 30 pg/mg EtG cut-off in hair representing heavy drinking. EtG may disappear faster from nail than expected from nail growth physiology. Nails are an alternative matrix to hair when measuring ethyl glucuronide (EtG). The present study indicate that EtG cut-off levels in nails should be higher compared to the established 30 pg/mg EtG cut-off in hair representing heavy drinking, and EtG may disappear faster from nail than expected.

  7. Childhood abuse is associated with increased hair cortisol levels among urban pregnant women

    PubMed Central

    Schreier, Hannah M C; Enlow, Michelle Bosquet; Ritz, Thomas; Gennings, Chris; Wright, Rosalind J

    2015-01-01

    Background Hypothalamic–pituitary–adrenal (HPA) axis activity is known to be altered following events such as childhood abuse. However, despite potential adverse consequences for the offspring of women who have experienced abuse, very little is known about altered HPA axis activity during pregnancy. Methods During pregnancy, 180 women from diverse racial/ethnic backgrounds reported on their exposure to emotional, physical and/or sexual abuse before the age of 11, and general post-traumatic stress symptoms (ie, not limited to childhood years or abuse experiences). Around delivery, they provided hair samples for the assessment of cortisol levels during pregnancy. Hair cortisol was assessed for each pregnancy trimester. The effect of childhood abuse on hair cortisol was assessed using mixed-effects analyses of covariance models allowing for within-subject correlated observations, and were first performed in the entire sample and subsequently stratified by race/ethnicity. Results Controlling for post-traumatic stress symptoms, hair cortisol levels varied by history of child abuse, F(2,166)=3.66, p=0.028. Childhood physical and/or sexual abuse was associated with greater hair cortisol levels, t(166)=2.65, p=0.009, compared with no history of abuse. Because childhood rates of abuse and hair cortisol levels varied by race/ethnicity, analyses were stratified by race/ethnicity. The associations between history of abuse and cortisol levels were only significant among black women, F(2,23)=5.37, p=0.012. Conclusions Childhood abuse, especially physical and/or sexual abuse, is associated with differences in cortisol production during pregnancy, particularly among black women. Future research should investigate how these differences impact physical and mental health outcomes among offspring of affected women. PMID:26219886

  8. Childhood abuse is associated with increased hair cortisol levels among urban pregnant women.

    PubMed

    Schreier, Hannah M C; Enlow, Michelle Bosquet; Ritz, Thomas; Gennings, Chris; Wright, Rosalind J

    2015-12-01

    Hypothalamic-pituitary-adrenal (HPA) axis activity is known to be altered following events such as childhood abuse. However, despite potential adverse consequences for the offspring of women who have experienced abuse, very little is known about altered HPA axis activity during pregnancy. During pregnancy, 180 women from diverse racial/ethnic backgrounds reported on their exposure to emotional, physical and/or sexual abuse before the age of 11, and general post-traumatic stress symptoms (ie, not limited to childhood years or abuse experiences). Around delivery, they provided hair samples for the assessment of cortisol levels during pregnancy. Hair cortisol was assessed for each pregnancy trimester. The effect of childhood abuse on hair cortisol was assessed using mixed-effects analyses of covariance models allowing for within-subject correlated observations, and were first performed in the entire sample and subsequently stratified by race/ethnicity. Controlling for post-traumatic stress symptoms, hair cortisol levels varied by history of child abuse, F(2,166)=3.66, p=0.028. Childhood physical and/or sexual abuse was associated with greater hair cortisol levels, t(166)=2.65, p=0.009, compared with no history of abuse. Because childhood rates of abuse and hair cortisol levels varied by race/ethnicity, analyses were stratified by race/ethnicity. The associations between history of abuse and cortisol levels were only significant among black women, F(2,23)=5.37, p=0.012. Childhood abuse, especially physical and/or sexual abuse, is associated with differences in cortisol production during pregnancy, particularly among black women. Future research should investigate how these differences impact physical and mental health outcomes among offspring of affected women. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  9. The diagnostics of diabetes mellitus based on ensemble modeling and hair/urine element level analysis.

    PubMed

    Chen, Hui; Tan, Chao; Lin, Zan; Wu, Tong

    2014-07-01

    The aim of the present work focuses on exploring the feasibility of analyzing the relationship between diabetes mellitus and several element levels in hair/urine specimens by chemometrics. A dataset involving 211 specimens and eight element concentrations was used. The control group was divided into three age subsets in order to analyze the influence of age. It was found that the most obvious difference was the effect of age on the level of zinc and iron. The decline of iron concentration with age in hair was exactly consistent with the opposite trend in urine. Principal component analysis (PCA) was used as a tool for a preliminary evaluation of the data. Both ensemble and single support vector machine (SVM) algorithms were used as the classification tools. On average, the accuracy, sensitivity and specificity of ensemble SVM models were 99%, 100%, 99% and 97%, 89%, 99% for hair and urine samples, respectively. The findings indicate that hair samples are superior to urine samples. Even so, it can provide more valuable information for prevention, diagnostics, treatment and research of diabetes by simultaneously analyzing the hair and urine samples.

  10. Hair cortisol levels as a retrospective marker of hypothalamic-pituitary axis activity throughout pregnancy: Comparison to salivary cortisol

    PubMed Central

    D’Anna-Hernandez, Kimberly L.; Ross, Randal G.; Natvig, Crystal L.; Laudenslager, Mark L.

    2011-01-01

    Maternal stress during pregnancy is associated with negative maternal/child outcomes. One potential biomarker of the maternal stress response is cortisol, a product of activity of the hypothalamic-pituitary-adrenal axis. This study evaluated cortisol levels in hair throughout pregnancy as a marker of total cortisol release. Cortisol levels in hair have been shown to be easily quantifiable and may be representative of total cortisol release more than single saliva or serum measures. Hair cortisol provides a simple way to monitor total cortisol release over an extended period of time. Hair cortisol levels were determined from each trimester (15, 26 and 36 wks gestation) and 3 months postpartum. Hair cortisol levels were compared to diurnal salivary cortisol collected over 3 days (3 times/day) at 14, 18, 23, 29, and 34 wks gestational age and 6 wks postpartum from 21 pregnant women. Both salivary and hair cortisol levels rose during pregnancy as expected. Hair cortisol and diurnal salivary cortisol area under the curve with respect to ground (AUCg) were also correlated throughout pregnancy. Levels of cortisol in hair are a valid and useful tool to measure long-term cortisol activity. Hair cortisol avoids methodological problems associated with collection other cortisol measures such as plasma, urine, or saliva and is a reliable metric of HPA activity throughout pregnancy reflecting total cortisol release over an extended period. PMID:21397617

  11. Transport of pyruvate into mitochondria is involved in methylmercury toxicity.

    PubMed

    Lee, Jin-Yong; Ishida, Yosuke; Takahashi, Tsutomu; Naganuma, Akira; Hwang, Gi-Wook

    2016-02-22

    We have previously demonstrated that the overexpression of enzymes involved in the production of pyruvate, enolase 2 (Eno2) and D-lactate dehydrogenase (Dld3) renders yeast highly sensitive to methylmercury and that the promotion of intracellular pyruvate synthesis may be involved in intensifying the toxicity of methylmercury. In the present study, we showed that the addition of pyruvate to culture media in non-toxic concentrations significantly enhanced the sensitivity of yeast and human neuroblastoma cells to methylmercury. The results also suggested that methylmercury promoted the transport of pyruvate into mitochondria and that the increased pyruvate concentrations in mitochondria were involved in intensifying the toxicity of methylmercury without pyruvate being converted to acetyl-CoA. Furthermore, in human neuroblastoma cells, methylmercury treatment alone decreased the mitochondrial membrane potential, and the addition of pyruvate led to a further significant decrease. In addition, treatment with N-acetylcysteine (an antioxidant) significantly alleviated the toxicity of methylmercury and significantly inhibited the intensification of methylmercury toxicity by pyruvate. Based on these data, we hypothesize that methylmercury exerts its toxicity by raising the level of pyruvate in mitochondria and that mitochondrial dysfunction and increased levels of reactive oxygen species are involved in the action of pyruvate.

  12. Transport of pyruvate into mitochondria is involved in methylmercury toxicity

    PubMed Central

    Lee, Jin-Yong; Ishida, Yosuke; Takahashi, Tsutomu; Naganuma, Akira; Hwang, Gi-Wook

    2016-01-01

    We have previously demonstrated that the overexpression of enzymes involved in the production of pyruvate, enolase 2 (Eno2) and D-lactate dehydrogenase (Dld3) renders yeast highly sensitive to methylmercury and that the promotion of intracellular pyruvate synthesis may be involved in intensifying the toxicity of methylmercury. In the present study, we showed that the addition of pyruvate to culture media in non-toxic concentrations significantly enhanced the sensitivity of yeast and human neuroblastoma cells to methylmercury. The results also suggested that methylmercury promoted the transport of pyruvate into mitochondria and that the increased pyruvate concentrations in mitochondria were involved in intensifying the toxicity of methylmercury without pyruvate being converted to acetyl-CoA. Furthermore, in human neuroblastoma cells, methylmercury treatment alone decreased the mitochondrial membrane potential, and the addition of pyruvate led to a further significant decrease. In addition, treatment with N-acetylcysteine (an antioxidant) significantly alleviated the toxicity of methylmercury and significantly inhibited the intensification of methylmercury toxicity by pyruvate. Based on these data, we hypothesize that methylmercury exerts its toxicity by raising the level of pyruvate in mitochondria and that mitochondrial dysfunction and increased levels of reactive oxygen species are involved in the action of pyruvate. PMID:26899208

  13. Determination of ethyl glucuronide levels in hair for the assessment of alcohol abstinence.

    PubMed

    Pirro, V; Di Corcia, D; Seganti, F; Salomone, A; Vincenti, M

    2013-10-10

    This study examined the potential of a highly sensitive LC-MS/MS method for the determination of EtG in head hair (i) to ascertain alcohol abstinence, (ii) to estimate the basal level of EtG (sub-ppb concentrations) in head hair in a population of alcohol abstainers and (iii) to suggest a revision of cut-off values for assessing alcohol abstinence. An UHPLC-MS/MS protocol previously developed was modified and validated again to detect low EtG levels in head hair samples from a population of 44 certain abstainers and teetotalers. Basal level of EtG in hair was determined by a standard addition quantification method. The validated UHPLC-MS/MS method allowed detecting and quantifying 0.5 and 1.0 pg/mg of EtG in hair, respectively. EtG concentrations lower than 1.0 pg/mg were determined for 95% of abstainers; 30% of them had non-detectable (<0.5 pg/mg) EtG values. Two samples evidenced EtG concentrations higher than 1.0 pg/mg that were subsequently explained by unintentional ethanol exposure. The method's feature of high analytical sensitivity makes it particularly suitable for alcohol abstinence ascertainment and, in the same time, allows to tentatively estimate basal EtG concentrations in hair around 0.8±0.4 pg/mg. This finding opens a discussion on the possible origin of basal EtG concentration and potential sources of bias in the evaluation of alcohol abstinence. Cut-off value in the range of 1.0-2.0 pg/mg can be reliably proposed to support alcohol abstinence. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Levels of selected trace metals in hair of urban and rural adult male population of Pakistan

    SciTech Connect

    Ashraf, W.; Jaffar, M.; Mohammad, D.

    1995-02-01

    Human scalp hair as a biopsy material may well serve the purpose of estimating the degree of human exposure to environmental contaminants, especially trace metals. To this effect, the levels of trace metals in hair of various groups of population living in areas with varying extent of environmental exposure are generally compared together. Such comparative evaluations are important since they are unique for each group of population and probably reflect not only a number of factors of genetical, nutritional and environmental origin, but also indicate relationship with factors such as food, ambient air, drinking water, occupational exposure, age, race, sex and metabolic condition etc. Also there are some elements which are selectively deposited in hair and may thus provide clinical information on the level of exposure and toxication. The aim of the present study was two-fold: to collect base-line trace metal data on hair and to evaluate the metal levels as measure of the nutritional status of the relevant groups of urban and rural population in terms of industrial, agricultural and occupation exposure. For this purpose, scalp hair samples were obtained from donors belonging to urban adult male population from the city of Peshawer and a rural town, Jamrood and were investigated for three essential metals (Na, K and Zn) and four non-essential metals (Co, Hg, As and Ag) by AAS technique. The impact of urban and rural environments, including the food habits of individuals, on trace metal distribution in scalp hair of the two classes of population is then reviewed with reference to the literature data available from other parts of the world. 16 refs., 5 tabs.

  15. Organ-level quorum sensing directs regeneration in hair stem cell populations

    PubMed Central

    Chen, Chih-Chiang; Wang, Lei; Plikus, Maksim V.; Jiang, Ting Xin; Murray, Philip J.; Ramos, Raul; Guerrero-Juarez, Christian F.; Hughes, Michael W; Lee, Oscar K.; Shi, Songtao; Widelitz, Randall B.; Lander, Arthur D.; Chuong, Cheng Ming

    2015-01-01

    SUMMARY Coordinated organ behavior is crucial for an effective response to environmental stimuli. By studying regeneration of hair follicles in response to patterned hair removal, we demonstrate that organ-level quorum sensing allows coordinated responses to skin injury. Removing hair at different densities leads to a regeneration of up to 5 times more neighboring, unplucked resting hairs, indicating activation of a collective decision-making process. Through data modeling, the range of the quorum signal was estimated to be on the order of 1 mm, greater than expected for a diffusible molecular cue. Molecular and genetic analysis uncovered a two-step mechanism, where release of CCL2 from injured hairs leads to recruitment of TNF-α secreting macrophages, which accumulate and signal to both plucked and unplucked follicles. By coupling immune response with regeneration, this mechanism allows skin to respond predictively to distress, disregarding mild injury, while meeting stronger injury with full-scale cooperative activation of stem cells. PMID:25860610

  16. Hair zinc levels and the efficacy of oral zinc supplementation in patients with atopic dermatitis.

    PubMed

    Kim, Jeong Eun; Yoo, Seo Rye; Jeong, Myeong Gil; Ko, Joo Yeon; Ro, Young Suck

    2014-09-01

    Zinc deficiency in patients with atopic dermatitis (AD) and the use of zinc supplementation is still controversial. We measured hair zinc levels in 58 children with AD and 43 controls (age range 2-14 years). We also investigated the efficacy of oral zinc supplementation in AD patients with low hair zinc levels by comparing eczema assessment severity index (EASI), transepidermal water loss (TEWL), and visual analogue scales for pruritus and sleep disturbance in patients receiving zinc supplementation (Group A) and others not receiving supplementation (Group B). At baseline, the mean zinc level was significantly reduced in AD patients (113.1 μg/g vs. 130.9 μg/g, p = 0.012). After 8 weeks of supplement, hair zinc level increased significantly in Group A (p < 0.001), and EASI scores, TEWL, and visual analogue scales for pruritus improved more in Group A than in Group B (p = 0.044, 0.015 and < 0.001, respectively). Thus, oral zinc supplementation may be effective in AD patients with low hair zinc levels.

  17. Determinants of hair cortisol and hair cortisone concentrations in adults.

    PubMed

    Staufenbiel, Sabine M; Penninx, Brenda W J H; de Rijke, Yolanda B; van den Akker, Erica L T; van Rossum, Elisabeth F C

    2015-10-01

    The analysis of hair cortisol concentrations (HairF) is a promising new tool for the assessment of long-term cortisol. With the development of multiple steroid analyses by means of liquid chromatography tandem-mass spectrometry (LC-MS/MS), the analysis of cortisone in hair (HairE) has also been facilitated. However, the influence of various types of determinants on HairF and HairE is still largely unknown. This study systematically assesses the influence of sociodemographic, health, lifestyle, and hair (treatment) characteristics on HairF and HairE. Data of 760 psychiatrically healthy participants (71.8% female, mean age 45.89 years) of the Netherlands Study of Depression and Anxiety (NESDA) were used. HairF and HairE were measured in the proximal 3 cm of scalp hair, using LC-MS/MS. HairF and HairE strongly correlated. In simple linear regressions, HairF and HairE were higher in older age, in presence of diabetes mellitus, and in men compared to women. More frequent washing of the hair was associated with lower HairF and HairE. Darker hair colours were associated with higher HairF and HairE. An effect of season and of use of oral contraceptives was found for HairF. After full mutual adjustment, only age, presence of diabetes mellitus, hair washing frequency, and season remained significant determinants of HairF. This large-scale study shows that HairF and HairE are upregulated in older age and in the presence of diabetes mellitus. This suggests that these levels are important for somatic health and should be taken into account when using hair corticosteroid analysis in future studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. BMI and levels of zinc, copper in hair, serum and urine of Turkish male patients with androgenetic alopecia.

    PubMed

    Ozturk, Perihan; Kurutas, Ergul; Ataseven, Arzu; Dokur, Neslihan; Gumusalan, Yakup; Gorur, Ayşegul; Tamer, Lulufer; Inaloz, Serhat

    2014-07-01

    Male pattern androgenetic alopecia is characterized by progressive hair loss from the scalp. It is known that imbalances of some trace elements play a role in the pathomechanism of many forms of alopecia. The aim of this study was to evaluate the levels of zinc and copper in hair, serum and urine samples of Turkish males with male pattern androgenetic alopecia and to compare with healthy controls. 116 males with male pattern androgenetic alopecia and 100 controls were involved in this study. Levels of zinc and copper in hair were decreased significantly in the patients (p<0.05), although zinc and copper levels of serum and urine were not different between patients and controls (p>0.05). Body mass index of patients were higher than control group. In addition, in the group with body mass index of 25 and lower zinc level in hair and urine, copper level in serum were significantly higher (p<0.05). Body mass index was negatively correlated with hair zinc levels. We thought that decreased zinc and copper levels in hair may play a role in the etiology of male pattern androgenetic alopecia. In addition, obesity by making changes in the balance of the trace elements in hair, serum and urine may play a role in male pattern androgenetic alopecia. Hence, assessing the levels of trace elements in hair of male pattern androgenetic alopecia patients may be more valuable compared to serum and urine for treatment planning. Copyright © 2014 Elsevier GmbH. All rights reserved.

  19. Low level laser therapy and hair regrowth: an evidence-based review.

    PubMed

    Zarei, Mina; Wikramanayake, Tongyu C; Falto-Aizpurua, Leyre; Schachner, Lawrence A; Jimenez, Joaquin J

    2016-02-01

    Despite the current treatment options for different types of alopecia, there is a need for more effective management options. Recently, low-level laser therapy (LLLT) was evaluated for stimulating hair growth. Here, we reviewed the current evidence on the LLLT effects with an evidence-based approach, focusing more on randomized controlled studies by critically evaluating them. In order to investigate whether in individuals presenting with hair loss (male pattern hair loss (MPHL), female pattern hair loss (FPHL), alopecia areata (AA), and chemotherapy-induced alopecia (CIA)) LLLT is effective for hair regrowth, several databases including PubMed, Google Scholar, Medline, Embase, and Cochrane Database were searched using the following keywords: Alopecia, Hair loss, Hair growth, Low level laser therapy, Low level light therapy, Low energy laser irradiation, and Photobiomodulation. From the searches, 21 relevant studies were summarized in this review including 2 in vitro, 7 animal, and 12 clinical studies. Among clinical studies, only five were randomized controlled trials (RCTs), which evaluated LLLT effect on male and female pattern hair loss. The RCTs were critically appraised using the created checklist according to the Critical Appraisal for Therapy Articles Worksheet created by the Center of Evidence-Based Medicine, Oxford. The results demonstrated that all the performed RCTs have moderate to high quality of evidence. However, only one out of five studies performed intention-to-treat analysis, and only another study reported the method of randomization and subsequent concealment of allocation clearly; all other studies did not include this very important information in their reports. None of these studies reported the treatment effect of factors such as number needed to treat. Based on this review on all the available evidence about effect of LLLT in alopecia, we found that the FDA-cleared LLLT devices are both safe and effective in patients with MPHL and FPHL

  20. Hair cortisol levels, psychological stress and psychopathological symptoms as predictors of postpartum depression.

    PubMed

    Caparros-Gonzalez, Rafael A; Romero-Gonzalez, Borja; Strivens-Vilchez, Helen; Gonzalez-Perez, Raquel; Martinez-Augustin, Olga; Peralta-Ramirez, Maria Isabel

    2017-01-01

    Postpartum depression affects a huge number of women and has detrimental consequences. Knowing the factors associated with postpartum depression during pregnancy can help its prevention. Although there is evidence surrounding behavioral or psychological predictors of postpartum depression, there is a lack of evidence of biological forecasters. The aim of this study was to analyze the sociodemographic, obstetric, and psychological variables along with hair cortisol levels during the first, second, and third trimesters of pregnancy that could predict postpartum depression symptoms. A sample of 44 pregnant women was assessed during 3 trimesters of pregnancy and the postpartum period using psychological questionnaires and hair cortisol levels. Participants were divided into 2 groups: a group with postpartum depression symptoms and a group with no postpartum depression symptoms. Results showed significant positive differences between groups in the first trimester regarding the Somatization subscale of the SCL-90-R (p < .05). In the second trimester, significant differences were found in the Somatization, Depression, Anxiety, and GSI subscales (p < .05). In the third trimester significant differences between both groups were found regarding pregnancy-specific stress. We found significant positive differences between groups regarding hair cortisol levels in the first and the third trimester. Hair cortisol levels could predict 21.7% of the variance of postpartum depression symptoms. In conclusion, our study provided evidence that psychopathological symptoms, pregnancy-specific stress, and hair cortisol levels can predict postpartum depression symptoms at different time-points during pregnancy. These findings can be applied in future studies and improve maternal care in clinical settings.

  1. Hair cortisol levels, psychological stress and psychopathological symptoms as predictors of postpartum depression

    PubMed Central

    Caparros-Gonzalez, Rafael A.; Strivens-Vilchez, Helen; Gonzalez-Perez, Raquel; Martinez-Augustin, Olga; Peralta-Ramirez, Maria Isabel

    2017-01-01

    Postpartum depression affects a huge number of women and has detrimental consequences. Knowing the factors associated with postpartum depression during pregnancy can help its prevention. Although there is evidence surrounding behavioral or psychological predictors of postpartum depression, there is a lack of evidence of biological forecasters. The aim of this study was to analyze the sociodemographic, obstetric, and psychological variables along with hair cortisol levels during the first, second, and third trimesters of pregnancy that could predict postpartum depression symptoms. A sample of 44 pregnant women was assessed during 3 trimesters of pregnancy and the postpartum period using psychological questionnaires and hair cortisol levels. Participants were divided into 2 groups: a group with postpartum depression symptoms and a group with no postpartum depression symptoms. Results showed significant positive differences between groups in the first trimester regarding the Somatization subscale of the SCL-90-R (p < .05). In the second trimester, significant differences were found in the Somatization, Depression, Anxiety, and GSI subscales (p < .05). In the third trimester significant differences between both groups were found regarding pregnancy-specific stress. We found significant positive differences between groups regarding hair cortisol levels in the first and the third trimester. Hair cortisol levels could predict 21.7% of the variance of postpartum depression symptoms. In conclusion, our study provided evidence that psychopathological symptoms, pregnancy-specific stress, and hair cortisol levels can predict postpartum depression symptoms at different time-points during pregnancy. These findings can be applied in future studies and improve maternal care in clinical settings. PMID:28846691

  2. Nanotribological effects of silicone type, silicone deposition level, and surfactant type on human hair using atomic force microscopy.

    PubMed

    La Torre, Carmen; Bhushan, Bharat

    2006-01-01

    The atomic/friction force microscope (AFM/FFM) has recently become an important tool for studying the micro/nanoscale structure and tribological properties of human hair. Of particular interest to hair and beauty care science is how common hair-care materials, such as conditioner, deposit onto and change hair's tribological properties, since these properties are closely tied to product performance. Since a conditioner is a complex network of many different ingredients (including silicones for lubrication and cationic surfactants for static control and gel network formulation), studying the effects of these individual components can give insight into the significance each has on hair properties. In this study, AFM/FFM is used to conduct nanotribological studies of surface roughness, friction force, and adhesive forces as a function of silicone type, silicone deposition level, and cationic surfactant type. Changes in the coefficient of friction as a result of soaking hair in de-ionized water are also discussed.

  3. A new mass screening method for methylmercury poisoning using mercury-volatilizing bacteria from Minamata Bay.

    PubMed

    Nakamura, K; Naruse, I; Takizawa, Y

    1999-09-01

    A simplified mass screening method for methylmercury exposure was developed using methylmercury-volatilizing bacteria from Minamata Bay. Some bacteria can transform methylmercury into mercury vapor. Most mercury in the hair is methylmercury, which is readily extracted with HCl solution. Black spots are formed on X-ray film due to the reduction of Ag(+) emulsion with mercury vapor produced by methylmercury-volatilizing bacteria. By exploiting these characteristics, a screening method was developed, whereby the fur of rats injected with methylmercury chloride formed clear black spots on X-ray film, whereas the fur of rats injected with saline did not. Subsequently, 50 human hair samples were examined using this mass screening method. The method identified people who had high mercury concentration, over 20 microg/g. A few thousand hair samples may be screened in a day using this method because it is rapid, simple, and economical. This method, therefore, enables screening of persons with methylmercury poisoning in mercury-polluted areas.

  4. The role of gut microbiota in fetal methylmercury exposure: Insights from a pilot study

    DOE PAGES

    Rothenberg, Sarah E.; Keiser, Sharon; Ajami, Nadim J.; ...

    2016-02-01

    The mechanisms by which gut microbiota contribute to methylmercury metabolism remain unclear. Among a cohort of pregnant mothers, the main objectives of our pilot study were to determine 1) associations between gut microbiota and mercury concentrations in biomarkers (stool, hair and cord blood) and 2) the contributions of gut microbial mercury methylation/demethylation to stool methylmercury. Moreover, for pregnant women (36-39 weeks gestation, n=17) donated hair and stool specimens, and cord blood was collected for a subset (n=7). The diversity of gut microbiota was determined using 16S rRNA gene profiling (n=17). For 6 stool samples with highest/lowest methylmercury concentrations, metagenomic wholemore » genome shotgun sequencing was employed to search for one mercury methylation gene (hgcA), and two mer operon genes involved in methylmercury detoxification (merA and merB). There were seventeen bacterial genera that were significantly correlated (increasing or decreasing) with stool methylmercury, stool inorganic mercury, or hair total mercury; however, aside from one genus, there was no overlap between biomarkers. No definitive matches for hgcA or merB, while merA were detected at low concentrations in all six samples. Proportional differences in stool methylmercury were not likely attributed to gut microbiota through methylation/demethylation. Gut microbiota potentially altered methylmercury metabolism using indirect pathways.« less

  5. The role of gut microbiota in fetal methylmercury exposure: Insights from a pilot study

    SciTech Connect

    Rothenberg, Sarah E.; Keiser, Sharon; Ajami, Nadim J.; Wong, Matthew C.; Gesell, Jonathan; Petrosino, Joseph F.; Johs, Alexander

    2016-02-01

    The mechanisms by which gut microbiota contribute to methylmercury metabolism remain unclear. Among a cohort of pregnant mothers, the main objectives of our pilot study were to determine 1) associations between gut microbiota and mercury concentrations in biomarkers (stool, hair and cord blood) and 2) the contributions of gut microbial mercury methylation/demethylation to stool methylmercury. Moreover, for pregnant women (36-39 weeks gestation, n=17) donated hair and stool specimens, and cord blood was collected for a subset (n=7). The diversity of gut microbiota was determined using 16S rRNA gene profiling (n=17). For 6 stool samples with highest/lowest methylmercury concentrations, metagenomic whole genome shotgun sequencing was employed to search for one mercury methylation gene (hgcA), and two mer operon genes involved in methylmercury detoxification (merA and merB). There were seventeen bacterial genera that were significantly correlated (increasing or decreasing) with stool methylmercury, stool inorganic mercury, or hair total mercury; however, aside from one genus, there was no overlap between biomarkers. No definitive matches for hgcA or merB, while merA were detected at low concentrations in all six samples. Proportional differences in stool methylmercury were not likely attributed to gut microbiota through methylation/demethylation. Gut microbiota potentially altered methylmercury metabolism using indirect pathways.

  6. Ethyl glucuronide in hair: Is it a reliable marker of chronic high levels of alcohol consumption?

    PubMed

    Politi, Lucia; Morini, Luca; Leone, Fabio; Polettini, Aldo

    2006-10-01

    This study aims to investigate the relationship between ethanol daily intake (EDI) and the levels of ethyl glucuronide in hair. Ethyl glucuronide concentration was determined in hair samples from different classes of ethanol drinkers and results were compared with the reported information about drinking habits. Pavia, Italy. Twenty-two known alcoholics, 21 volunteers self-reporting an EDI from 2 to 60 g, and seven teetotallers were involved in this study. Ethyl glucuronide determination in hair samples was performed by liquid chromatography-tandem mass spectrometry (limit of detection: 2 pg/mg, lower limit of quantification: 3 pg/mg). Current known alcoholics (n = 21) had ethyl glucuronide hair concentration in the range 4.0-434.7 pg/mg (average: 62.8, median 37.4 pg/mg); ethyl glucuronide was not detected in hair samples from teetotallers (n = 7); all volunteers reporting an EDI of at least 30 g ('non-moderate drinkers' according to the US Department of Health and Human Services) tested positive for ethyl glucuronide (cut-off: 4 pg/mg). All volunteers declaring an ethanol daily intake higher than 40 g ('heavy drinkers' according to the World Health Organization, Regional Committee for Europe) tested positive for this compound (cut-off: 5 pg/mg). The application of a cut-off of either 4 pg/mg or 5 pg/mg resulted in one false positive, coming from a volunteer asserting an ethanol daily intake of 30 g. No false negatives were found. The concentration of ethyl glucuronide in hair appears to correlate with EDI.

  7. The level of toxic and essential trace elements in hair of petrochemical workers involved in different technological processes.

    PubMed

    Skalny, Anatoly V; Kaminskaya, Galina A; Krekesheva, Tatyana I; Abikenova, Sholpan K; Skalnaya, Margarita G; Berezkina, Elena S; Grabeklis, Andrei R; Tinkov, Alexey A

    2017-02-01

    The objective of the investigation is comparative analysis of hair trace element content in workers of different departments of petrochemical plant. A total of 75 men working in office (engineers), and departments 1 (D1), 3 (D3), and 4 (D4) of the petrochemical plant, as well as occupationally non-exposed persons, were examined. Hair trace element levels were analyzed using inductively coupled plasma mass spectrometry. The office workers were characterized by the highest hair As, Hg, Sn, I, and Si content as compared to the workers of other departments, whereas the level of those elements did not differ significantly from the control values. It is notable that hair Be levels in all employees of petrochemical plant were significantly lower, whereas Se content was significantly higher than that in unexposed controls. Hair toxic trace element content in workers directly involved in industrial processes did not differ significantly or was lower than that in the control group. At the same time, the highest levels of essential trace elements (Cr, Fe, and I) were observed in employees working in primary oil refining (D1). Hair levels of Co, I, and Li were maximal in persons of sulfur and bitumen-producing division (D4). The lowest levels of both essential and toxic trace elements in hair were detected in employees involved in production of liquefied gas, kerosene, and diesel fuel (D3). The obtained data demonstrate that involvement in different technological processes in petrochemical complex differentially affect hair trace element content in workers.

  8. Neurotoxicity from prenatal and postnatal exposure to methylmercury

    PubMed Central

    Grandjean, Philippe; Weihe, Pal; Debes, Frodi; Choi, Anna L.; Budtz-Jørgensen, Esben

    2014-01-01

    The extent to which postnatal methylmercury exposure contributes to neurobehavioral delays is uncertain. Confounding may occur because the child's dietary exposure likely correlates with the mother's. This conundrum was examined in the Faroese birth cohort 1 born in 1986–1987. Exposure parameters included mercury concentrations in maternal hair at parturition, cord blood, and child blood and hair at the age-7 clinical examination (N = 923). In regression analyses, the child's current blood-mercury at age 7 (N = 694) showed only weak associations with the neuropsychological test variables, but visuospatial memory revealed a significant negative association. Mutual adjustment caused decreases of the apparent effect of the prenatal exposure. However, such adjustment may lead to underestimations due to the presence of correlated, error-prone exposure variables. In structural equation models, all methylmercury exposure parameters were instead entered into a latent exposure variable that reflected the total methylmercury load. This latent exposure showed significant associations with neurodevelopmental deficits, with prenatal exposure providing the main information. However, postnatal methylmercury exposure appeared to contribute to neurotoxic effects, in particular in regard to visuospatial processing and memory. Thus, addition in the regression analysis of exposure information obtained at a different point in time was not informative and should be avoided. Further studies with better information on exposure profiles are needed to characterize the effects of postnatal methylmercury exposure. PMID:24681285

  9. An exploratory study of total mercury levels in archaeological caribou hair from northwest Alaska.

    PubMed

    Gerlach, S Craig; Duffy, Lawrence K; Murray, Maribeth S; Bowers, Peter M; Adams, Rachel; Verbrugge, David A

    2006-12-01

    Over the past ten years, total mercury (THg) levels have been surveyed in Alaskan wildlife and fish as part of the Arctic Monitoring and Assessment (AMAP). Beyond these studies there is little historical data on THg levels in important subsistence species for people in Alaska. A survey of THg in caribou hair from archaeological deposits would provide data to develop temporal trends for this region of the Arctic. Caribou hair from a Western Thule settlement beneath the Alaska native village of Deering (ca. AD 1150) show variability in hair THg values, with a mean level (86 ng/g) which is in the range that is observed in modern Rangifer sp. (caribou and reindeer). Hair from House 1 had a THg mean level of 99.6 ng/g and hair from House 2 had a THg mean of 64.2 ng/g. This is the earliest reported record of mercury in caribou associated with human subsistence activities in the western North American Arctic, and is a first step toward compilation of a needed database through which to measure and evaluate exposure to mercury by people who rely heavily on caribou as a food source. We hypothesize that similarity in mercury values in archaeological samples of caribou and in contemporary samples would give an additional perspective on human exposure to mercury through caribou harvest and consumption today. Since this hypothesis will be more useful if evaluated at a regional rather than global scale, further studies will be needed at different archaeological sites across Alaska to determine the generality of this observation in relation to geographic scale.

  10. Association of Hair Manganese Level with Symptoms in Attention-Deficit/Hyperactivity Disorder

    PubMed Central

    Shin, Dong-Won; Kim, Eun-Ji; Lim, Se-Won; Shin, Young-Chul; Oh, Kang-Seob

    2015-01-01

    Objective The study examined the association between hair manganese level and symptoms of attention-deficit/hyperactivity disorder (ADHD) in Korean children. Methods Forty clinic-referred children with ADHD and 43 normal control children participated in this study. The participants were 6-15 years old and were mainly from the urban area of Seoul, Korea. ADHD was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition and Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version-Korean Version. The severity and symptoms of ADHD was evaluated according to the ADHD Diagnostic System, and parent's Korean ADHD Rating Scale (K-ARS). All participants completed intelligence test and hair mineral analysis. We divided the data of hair Mn into two groups to determine whether a deficit or excess of Mn are associated with ADHD. Multiple logistic regression analyses were performed to identify hair manganese levels associated with ADHD, controlling for age, sex, and full scale intelligence quotient (IQ). Results The proportion of abnormal range Mn group was significantly high in ADHD compared to controls. However, after statistical control for covariates including age and sex, abnormal range Mn group was significantly associated with ADHD (OR=6.40, 95% CI=1.39-29.41, p=0.017). Conclusion The result of this study suggests that excess exposure or deficiency of Mn were associated with ADHD among children in Korea. Further investigation is needed to evaluate the effects of hair manganese levels on symptoms in ADHD. PMID:25670948

  11. Increased cortisol levels in hair of recent Ecstasy/MDMA users.

    PubMed

    Parrott, A C; Sands, H R; Jones, L; Clow, A; Evans, P; Downey, L A; Stalder, T

    2014-03-01

    Previous research has revealed an acute 8-fold increase in salivary cortisol following self-administrated Ecstasy/MDMA in dance clubbers. It is currently not known to what extent repeated usage impacts upon activity of the hypothalamic-pituitary-adrenal axis over a more prolonged period of time. This study investigated the integrated cortisol levels in 3-month hair samples from recent Ecstasy/MDMA users and non-user controls. One hundred and one unpaid participants (53 males, 48 females; mean age 21.75 years) completed the University of East London recreational drug use questionnaire, modified to cover the past 3-months of usage. They comprised 32 light recent Ecstasy/MDMA users (1-4 times in last 3 months), 23 recent heavy MDMA users (+5 times in last 3 months), and 54 non-user controls. Volunteers provided 3 cm hair samples for cortisol analysis. Hair cortisol levels were observed to be significantly higher in recent heavy MDMA users (mean = 55.0 ± 80.1 pg/mg), compared to recent light MDMA users (19.4 ± 16.0 pg/mg; p=0.015), and to non-users (13.8 ± 6.1 pg/mg; p<0.001). Hence the regular use of Ecstasy/MDMA was associated with almost 4-fold raised hair cortisol levels, in comparison with non-user controls. The present results are consistent with the bio-energetic stress model for Ecstasy/MDMA, which predicts that repeated stimulant drug use may increase cortisol production acutely, and result in greater deposits of the hormone in hair. These data may also help explain the neurocognitive, psychiatric, and other psychobiological problems of some abstinent users. Future study design and directions for research concerning the psychoneuroendocrinological impact of MDMA are also discussed.

  12. Visual Evoked Potentials in Children Prenatally Exposed to Methylmercury

    PubMed Central

    Yorifuji, Takashi; Murata, Katsuyuki; Bjerve, Kristian S.; Choi, Anna L; Weihe, Pal; Grandjean, Philippe

    2013-01-01

    Prenatal exposure to methylmercury can cause both neurobehavioral deficits and neurophysiological changes. However, evidence of neurotoxic effects within the visual nervous system is inconsistent, possibly due to incomplete statistical adjustment for beneficial nutritional factors. We evaluated the effect of prenatal methylmercury exposure on visual evoked potential (VEP) latencies in Faroese children with elevated prenatal methylmercury exposure. A cohort of 182 singleton term births was assembled in the Faroe Islands during 1994–1995. At age 7 years, VEP tracings were obtained from 139 cohort subjects after exclusion of subjects with abnormal vision conditions. We used multiple regression analysis to evaluate the association of mercury concentrations in cord blood and maternal hair at parturition with VEP latencies after adjustment for potential confounders that included the cord-serum phospholipid concentration of n-3 polyunsaturated fatty acids (PUFAs) and the duration of breastfeeding. Unadjusted correlations between mercury exposure and VEP latencies were equivocal. Multiple regression models showed that increased mercury concentrations, especially in maternal hair, were associated with delayed latencies for VEP peak N145. After covariate adjustment, a delay of 2.22 ms (p=0.02) was seen for each doubling of the mercury concentration in maternal hair. In agreement with neuropsychological findings, the present study suggests that prenatal methylmercury exposure may have an adverse effect on VEP findings despite the absence of clinical toxicity to the visual system. However, this association was apparent only after adjustment for n-3 PUFA status. PMID:23548974

  13. Recent evidence from epidemiological studies on methylmercury toxicity.

    PubMed

    Murata, Katsuyuki; Yoshida, Minoru; Sakamoto, Mineshi; Iwai-Shimada, Miyuki; Yaginuma-Sakurai, Kozue; Tatsuta, Nozomi; Iwata, Toyoto; Karita, Kanae; Nakai, Kunihiko

    2011-09-01

    More than fifty years have passed since the outbreak of Minamata disease, and large-scale methylmercury poisoning due to industrial effluents or methylmercury-containing fungicide intoxication has scarcely happened in developed countries. On the other hand, widespread environmental mercury contamination has occurred in gold and mercury mining areas of developing countries. In this article, we provided an overview of recent studies addressing human health effects of methylmercury, which we searched using the PubMed of the US National Library of Medicine. The following suggestions were obtained for low-level methylmercury exposure: (1) In recent years, the proportion of human studies addressing methylmercury has tended to decrease. (2) Prenatal exposure to methylmercury through fish intake, even at low levels, adversely affects child development after adjusting for polychlorinated biphenyls and maternal fish intake during pregnancy, whereas maternal seafood intake has some benefits. (3) Long-term methylmercury exposure through consumption of fish such as bigeye tuna and swordfish may pose a potential risk of cardiac events involving sympathovagal imbalance. (4) In measuring methylmercury levels in preserved umbilical cord collected from inhabitants born in Minamata areas between 1945 and 1989, the elevated concentrations (≥1 mg/g) were observed mainly in inhabitants born between 1947 and 1968, and the peak coincided with the peak of acetaldehyde production in Minamata. (5) Since some developing countries appear to be in similar situations to Japan in the past, attention should be directed toward early recognition of a risky agent and precautions should be taken against it.

  14. Comparative observations on levels of mercury in scalp hair of humans from different Islands

    NASA Astrophysics Data System (ADS)

    Renzoni, Aristeo

    1992-09-01

    Following the Minamata events, an extraordinary number of studies concerning mercury toxicity and human health have been undertaken. Particular attention has been given to the evaluation of the dose-response relationship, i.e., the body burden at which (evaluated through the mercury analyses in blood or hair) the risk of poisoning begins. The results of a comparative study concerning levels of mercury in the hair of fishermen living in small islands who eat seafood more than four times per week show that in two areas only, and only in a few cases in these areas, the mercury in the hair exceeds the limit at which a possible risk could exist. In fact, the limit of 50 mg/g of total mercury in the hair (indicated as the lower limit above which a possible risk could occur) is surpassed by nine fishermen out of a total of 39 at station 1 and by four fishermen out of a total of 26 at station 3. The average value at station 1 is 36.38 mg/g and that at station 3 is 30.31 mg. Many countries have set legal limits of mercury for seafood, but evidently the system does not offer a true protection for man. Only the provisional tolerable weekly intake (PTWI), as repeatedly suggested by WHO, should be considered the best guideline to prevent possibly harmful consequences.

  15. Women with Fibromyalgia Have Lower Levels of Calcium, Magnesium, Iron and Manganese in Hair Mineral Analysis

    PubMed Central

    Kim, Young-Sang; Kim, Kwang-Min; Lee, Duck-Joo; Kim, Bom-Taeck; Park, Sat-Byul; Cho, Doo-Yeoun; Suh, Chang-Hee; Kim, Hyoun-Ah; Park, Rae-Woong

    2011-01-01

    Little is known about hair mineral status in fibromyalgia patients. This study evaluated the characteristics of hair minerals in female patients with fibromyalgia compared with a healthy reference group. Forty-four female patients diagnosed with fibromyalgia according to the American College of Rheumatology criteria were enrolled as the case group. Ageand body mass index-matched data were obtained from 122 control subjects enrolled during visit for a regular health check-up. Hair minerals were analyzed and compared between the two groups. The mean age was 43.7 yr. General characteristics were not different between the two groups. Fibromyalgia patients showed a significantly lower level of calcium (775 µg/g vs 1,093 µg/g), magnesium (52 µg/g vs 72 µg/g), iron (5.9 µg/g vs 7.1 µg/g), copper (28.3 µg/g vs 40.2 µg/g) and manganese (140 ng/g vs 190 ng/g). Calcium, magnesium, iron, and manganese were loaded in the same factor using factor analysis; the mean of this factor was significantly lower in fibromyalgia group in multivariate analysis with adjustment for potential confounders. In conclusion, the concentrations of calcium, magnesium, iron, and manganese in the hair of female patients with fibromyalgia are lower than of controls, even after adjustment of potential confounders. PMID:22022174

  16. High mercury levels in hair samples from residents of Taiji, a Japanese whaling town.

    PubMed

    Endo, Tetsuya; Haraguchi, Koichi

    2010-05-01

    We investigated the mercury concentrations in red meat from pilot whales consumed by some residents of the Japanese whaling town, Taiji, and in hair samples from 50 residents for their maker of mercury burden. The methyl mercury (M-Hg) level in the red meat was 5.9 microg/wet g, markedly higher than the US FDA action level and Cordex Alimentarius guideline level for predatory fish (1.0 microg/wet g). The average level of total mercury (T-Hg) in the hair from residents who ate whale meat more than once a month was 24.6 microg/g, whereas the average from the residents who did not consume any whale meat was 4.3 microg/g. The T-Hg concentrations in the hair from three donors exceeded 50 microg/g, the level for NOAEL set by WHO. The T-Hg level found in the Taiji whale meat consumers was markedly higher than that observed in the Japanese population overall (about 2 microg/g). (c) 2009 Elsevier Ltd. All rights reserved.

  17. Serum and Hair Mineral Levels in Children with Failure to Thrive According to the Type of Feeding Difficulties.

    PubMed

    Lee, Eun Hye; Yang, Hye Ran

    2017-01-01

    This study evaluated serum and hair mineral and trace element levels as well as levels of other nutritional factors affecting growth and appetite in young children with non-organic failure to thrive (NOFTT) based on the presence or types of feeding difficulty (FD). Between August 2012 and July 2015, 136 children less than 6 years of age with NOFTT were included. FD was diagnosed based on Wolfson criteria and divided into subtypes according to Chatoor's classification. Clinical data were reviewed, and serum and hair mineral levels were measured. Of all assessed serum and hair minerals, only hair sulfur contents differed significantly between subjects with and without infantile anorexia (39,392 ± 2211 vs. 40,332 ± 2551 μg/g, P = 0.034). There were no differences in serum and hair mineral levels between children with and without sensory food aversion. Hair copper contents were significantly lower in children with FD of reciprocity (12.3 ± 6.0 vs. 22.4 ± 25.1 μg/g, P = 0.049). While hair zinc contents were also lower, the difference was not statistically significant (49.2 ± 26.8 vs. 70.6 ± 41.0 μg/g, P = 0.055). Only hair manganese contents were significantly lower in children with posttraumatic FD (0.12 ± 0.04 vs. 0.26 ± 0.73 μg/g, P = 0.037). In conclusion, there were no differences in most serum and hair mineral levels in children with NOFTT, except for relatively lower hair levels of sulfur, copper and possibly zinc, and manganese in infantile anorexia, reciprocity, and posttraumatic types of FD, respectively.

  18. Mercury accumulation in fish species from the Persian Gulf and in human hair from fishermen.

    PubMed

    Agah, Homira; Leermakers, Martine; Gao, Yue; Fatemi, S M R; Katal, M Mohseni; Baeyens, Willy; Elskens, Marc

    2010-10-01

    Total and methylmercury concentrations were assessed in muscle and liver of 141 fish samples from the northern part of the Persian Gulf. All fish samples belonged to five different species: grunt, flathead, greasy grouper, tiger-tooth croaker, and silver pomfret. In addition, Hg and methylmercury were analyzed in scalp hair of 19 fishermen living in the same coastal stations of the Persian Gulf and consuming several fish meals a week. Total mercury concentrations in fish muscle and liver ranged from 0.01 to 1.35 microg g(-1) w.w. and from 0.02 to 1.30 microg g(-1) w.w., respectively. In fish muscle, 3% of the Hg concentrations were higher than 0.5 microg g(-1) w.w., which corresponds to the maximum acceptable WHO level, while 9% were in the range of polluted fish (between 0.3 and 0.5 microg g(-1) w.w.). The highest mercury concentrations in fish muscle were observed in flathead fish at Abadan (average of 0.68 microg g(-1) w.w.). Methylmercury fractions in fish muscle and liver amount to 34-99% (median 64%) and 24-70% (median 43%), respectively. The mean total Hg concentration in the fishermen's scalp hair amounted to 2.9 +/- 2.2 microg g(-1), with 68% in the form of methylmercury. Ninety-five percent of the Hg levels in the fishermen's hair were below 10 microg g(-1), which is the WHO warning limit. In addition, relationships between the mercury levels in hair, on the one hand, and exposure-related factors such as Hg levels in specific fish species, regional differences, and number of fish meals, on the other hand, are discussed. It appears that a significant correlation for example exists between Hg levels human hair and fish muscle or human hair and age and that mean mercury levels in fish muscle and human hair decreased from western (Abadan) to eastern (Abbas port) coastal sites.

  19. Types of hair loss and treatment options, including the novel low-level light therapy and its proposed mechanism.

    PubMed

    Ghanaat, Mahyar

    2010-09-01

    Androgenetic alopecia (AGA) is the most common form of hair loss in men, and female pattern hair loss (FPHL) is the most common form of hair loss in women. Traditional methods of treating hair loss have included minoxidil, finasteride, and surgical transplantation. Currently there is a myriad of new and experimental treatments. In addition, low-level light therapy (LLLT) has recently been approved by the United States Food and Drug Administration (FDA) for the treatment of hair loss. There are several theories and minimal clinical evidence of the safety and efficacy of LLLT, although most experts agree that it is safe. More in vitro studies are necessary to elucidate the mechanism and effectiveness at the cellular level, and more controlled studies are necessary to assess the role of this new treatment in the general population.

  20. Human Body Burden and Dietary Methylmercury Intake: The Relationship in a Rice-Consuming Population.

    PubMed

    Li, Ping; Feng, Xinbin; Chan, Hing-Man; Zhang, Xiaofeng; Du, Buyun

    2015-08-18

    Rice can be the main route of methylmercury (MeHg) exposure for rice-consuming populations living in area where mercury (Hg) is mined. However, the current risk assessment paradigm for MeHg exposure is based on epidemiological data collected from fish-consuming populations. This study was designed to evaluate the relationship between dietary MeHg intake and human body burden in a rice -consuming population from the Wanshan Hg mining area in China. Hair MeHg concentrations averaged 2.07 ± 1.79 μg/g, and the average blood MeHg concentration across the study area ranged from 2.20 to 9.36 μg/L. MeHg constituted 52.8 ± 17.5% and 71.7 ± 18.2% of total Hg (THg) on average in blood and hair samples, respectively. Blood and hair MeHg concentrations, rather than THg, can be used as a proxy of human MeHg exposure. Hair MeHg levels showed no significant monthly variation; however, hair THg can be impacted by inorganic Hg exposure. The toxicokinetic model of MeHg exposure based on fish consumption underestimated the human hair MeHg levels, and this may be a consequence of the high hair-to-blood MeHg ratio (361 ± 105) in the studied rice-consuming population. The use of risk assessment models based on fish consumption may not be appropriate for inland mining areas where rice is the staple food.

  1. Rice Methylmercury Exposure and Mitigation: A Comprehensive Review

    PubMed Central

    Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

    2014-01-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effect of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, which minimize methylmercury exposure through rice ingestion. PMID:24972509

  2. Rice methylmercury exposure and mitigation: a comprehensive review.

    PubMed

    Rothenberg, Sarah E; Windham-Myers, Lisamarie; Creswell, Joel E

    2014-08-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion.

  3. Rice methylmercury exposure and mitigation: a comprehensive review

    USGS Publications Warehouse

    Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

    2014-01-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion.

  4. Methylmercury: a new look at the risks.

    PubMed Central

    Mahaffey, K R

    1999-01-01

    In the US, exposure to methylmercury, a neurotoxin, occurs primarily through consumption of fish. Data from recent studies assessing the health impact of methylmercury exposure due to consumption of fish and other sources in the aquatic food web (shellfish, crustacea, and marine mammals) suggest adverse effects at levels previously considered safe. There is substantial variation in human methylmercury exposure based on differences in the frequency and amount of fish consumed and in the fish's mercury concentration. Although virtually all fish and other seafood contain at least trace amounts of methylmercury, large predatory fish species have the highest concentrations. Concerns have been expressed about mercury exposure levels in the US, particularly among sensitive populations, and discussions are underway about the standards used by various federal agencies to protect the public. In the 1997 Mercury Study Report to Congress, the US Environmental Protection Agency summarized the current state of knowledge on methylmercury's effects on the health of humans and wildlife; sources of mercury; and how mercury is distributed in the environment. This article summarizes some of the major findings in the Report to Congress and identifies issues of concern to the public health community. Images p396-a p397-a p399-a p406-a p408-a p410-a PMID:10590759

  5. Correlation between serum testosterone level and concentrations of copper and zinc in hair tissue.

    PubMed

    Chang, Chung Soo; Choi, Jong Bo; Kim, Hae Jin; Park, Sat Byul

    2011-12-01

    Testosterone deficiency is associated with late-onset hypogonadism. Micronutrients including copper (Cu) and zinc (Zn) influence testosterone synthesis. The association between micronutrient concentrations in hair tissue and serum testosterone was studied in Korean men. The subjects were 88 men 40-60 years of age who visited the health promotion center and an outpatient clinic of family medicine at a university hospital from March 2006 to February 2008. Population sociological features of the subjects were acquired by self-administered surveys and interview, height and weight were measured, serum total testosterone was determined in the morning, and Cu and Zn were quantified from hair tissue collected in the morning. Subjects with normal testosterone group had a significantly higher Zn level compared to low testosterone group (P = 0.003). Significant negative correlations were evident between total testosterone and Cu level (r = -0.252, P = 0.022), and the Cu/Zn ratio (r = -0.288, P = 0.008). Normal testosterone is associated with a higher Zn level. Decreased serum testosterone is significantly associated with a high level of Cu and elevated Cu/Zn ratio in hair tissue.

  6. Levels of metals in hair of young children as an indicator of environmental pollution

    SciTech Connect

    Wibowo, A.A.; Herber, R.F.; Das, H.A.; Roeleveld, N.; Zielhuis, R.L.

    1986-08-01

    In 1982 the levels of lead (Pb), cadmium (Cd), vanadium (V), copper (Cu), and selenium (Se) were determined in hair of 231 four- to five-year-old children. The objective was to explore the feasibility of using metal-in-hair levels in groups of children as an indicator of environmental pollution. The study was carried out in four areas, which were assumed to differ in ambient pollution by metals. A questionnaire on personal data, socioeconomic status, intake of beverages, and life-style was completed by the parents. The metal-in-hair levels covered a large range. The variables pertaining to location together with sex, presence of a garden, and drinking of coffee and/or tea explained 32% of the variance of Pb, 24% of the variance of Cd, and 21% of the variance of V. The total variance explained by all measured questionnaire items was at best 38%. The location was the most important factor. Cu and Se levels did not differ between the locations.

  7. Effects of fixed orthodontic treatment on hair nickel and chromium levels: a 6-month prospective preliminary study.

    PubMed

    Amini, Fariborz; Mollaei, Mobina; Harandi, Saghar; Rakhshan, Vahid

    2015-03-01

    Although nickel and chromium are known as allergen and cytotoxic orthodontic metals, very few and controversial studies have assessed the effect of orthodontic treatment on their systemic levels reflected by their best biomarker of exposure, hair. This prospective preliminary study was conducted to evaluate hair nickel and chromium levels in fixed orthodontic patients. Scalp hair nickel/chromium concentrations of 12 female and 12 male fixed orthodontic patients were measured before treatment and 6 months later, using atomic absorption spectrophotometry. The effects of treatment, gender, and age on hair ions were analyzed statistically (α = 0.05). The patients' mean age was 18.38 ± 3.98 years. The mean nickel levels were 0.1380 ± 0.0570 and 0.6715 ± 0.1785 μg/g dry hair mass, respectively, in the baseline and sixth month of treatment. Chromium concentrations were 0.1455 ± 0.0769 and 0.1683 ± 0.0707 μg/g dry hair mass, respectively. After 6 months, nickel increased for 387 % (paired t test P = 0.0000) and chromium increased for 16 % (P = 0.0002). No significant correlations were observed between any ion levels with age or gender (Spearman P > 0.2). Within the limitations of this preliminary study, it seems that 6 months of fixed orthodontic treatment might increase levels of hair nickel and chromium. Future larger studies are necessary to validate these results.

  8. Reducing uncertainty in risk modeling for methylmercury exposure

    SciTech Connect

    Ponce, R.; Egeland, G.; Middaugh, J.; Lee, R.

    1995-12-31

    The biomagnification and bioaccumulation of methylmercury in marine species represents a challenge for risk assessment related to the consumption of subsistence foods in Alaska. Because of the profound impact that food consumption advisories have on indigenous peoples seeking to preserve a way of life, there is a need to reduce uncertainty in risk assessment. Thus, research was initiated to reduce the uncertainty in assessing the health risks associated with the consumption of subsistence foods. Because marine subsistence foods typically contain elevated levels of methylmercury, preliminary research efforts have focused on methylmercury as the principal chemical of concern. Of particular interest are the antagonistic effects of selenium on methylmercury toxicity. Because of this antagonism, methylmercury exposure through the consumption of marine mammal meat (with high selenium) may not be as toxic as comparable exposures through other sources of dietary intake, such as in the contaminated bread episode of Iraq (containing relatively low selenium). This hypothesis is supported by animal experiments showing reduced toxicity of methylmercury associated with marine mammal meat, by the antagonistic influence of selenium on methylmercury toxicity, and by negative clinical findings in adult populations exposed to methylmercury through a marine diet not subject to industrial contamination. Exploratory model development is underway to identify potential improvements and applications of current deterministic and probabilistic models, particularly by incorporating selenium as an antagonist in risk modeling methods.

  9. Assessment of gender and age effects on serum and hair trace element levels in children with autism spectrum disorder.

    PubMed

    Skalny, Anatoly V; Simashkova, Natalia V; Skalnaya, Anastasia A; Klyushnik, Tatiana P; Bjørklund, Geir; Skalnaya, Margarita G; Tinkov, Alexey A

    2017-06-29

    The primary objective of the present study was to investigate the levels of essential trace elements in hair and serum in children with autism spectrum disorder (ASD) and investigate the age and gender effects. Children with ASD were characterized by significantly higher levels of copper (Cu) (+8%), iron (Fe) (+5%), and selenium (Se) (+13%) levels in hair and only 8% higher serum Cu levels. After stratification for gender, ASD boys were characterized by significantly increased hair Cu (+ 25%), Fe (+ 25%), and Se (+ 9%) levels, whereas in girls only Se content was elevated (+ 15%). Boys and girls suffering from ASD were characterized by significantly higher serum manganese (Mn) (+20%) and Cu (+18%) as compared to the control values, respectively. In the group of younger children (2-5 years), no significant group difference in hair trace element levels was detected, whereas serum Cu levels were significantly higher (+7%). In turn, the serum concentration of Se in ASD children was 11% lower than that in neurotypical children. In the group of older children with ASD (6-10 years), hair Fe and Se levels were 21% and 16% higher, whereas in serum only Cu levels were increased (+12%) as compared to the controls. Correlation analysis also revealed a different relationship between serum and hair trace element levels with respect to gender and age. Therefore, it is highly recommended to assess several bioindicative matrices for critical evaluation of trace element status in patients with ASD in order to develop adequate personalized nutritional correction.

  10. Hair arsenic levels and prevalence of arsenicosis in three Cambodian provinces.

    PubMed

    Hashim, Jamal Hisham; Radzi, Rozhan Syariff Mohamed; Aljunid, Syed Mohamed; Nur, Amrizal Muhammad; Ismail, Aniza; Baguma, David; Sthiannopkao, Suthipong; Phan, Kongkea; Wong, Ming Hung; Sao, Vibol; Yasin, Mohamed Salleh Mohamed

    2013-10-01

    Natural, inorganic arsenic contamination of groundwater threatens the health of more than 100 million people worldwide, including residents of the densely populated river deltas of South and Southeast Asia. Contaminated groundwater from tube wells in Cambodia was discovered in 2001 leading to the detection of the first cases of arsenicosis in 2006. The most affected area was the Kandal Province. The main objective of this study was to determine the prevalence of arsenicosis in Cambodia based on acceptable criteria, and to investigate the use of hair arsenic as a biomarker not only for arsenicosis-related signs but also for associated symptoms. A cross-sectional epidemiological study of 616 respondents from 3 purposely selected provinces within the Mekong River basin of Cambodia was conducted. The Kandal Province was chosen as a high arsenic-contaminated area, while the Kratie Province and Kampong Cham Province were chosen as moderate and low arsenic-contaminated areas, respectively. The most prevalent sign of arsenicosis was hypomelanosis with a prevalence of 14.5% among all respondents and 32.4% among respondents with a hair arsenic level of ≥1 μg/g. This was followed by hyperkeratosis, hyperpigmentation and mee's lines. Results also suggest a 1.0 μg/g hair arsenic level to be a practical cut off point for an indication of an arsenic contaminated individual. This hair arsenic level, together with the presence of one or more of the classical signs of arsenicosis, seems to be a practical criteria for a confirmed diagnosis. Based on these criteria, the overall prevalence of arsenicosis for all provinces was found to be 16.1%, with Kandal Province recording the highest prevalence of 35.5%. This prevalence is comparatively high when compared to that of other affected countries. The association between arsenicosis and the use of Chinese traditional medicine also needs further investigation. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Molecular composition of organic matter controls methylmercury formation in boreal lakes

    NASA Astrophysics Data System (ADS)

    Bravo, Andrea G.; Bouchet, Sylvain; Tolu, Julie; Björn, Erik; Mateos-Rivera, Alejandro; Bertilsson, Stefan

    2017-02-01

    A detailed understanding of the formation of the potent neurotoxic methylmercury is needed to explain the large observed variability in methylmercury levels in aquatic systems. While it is known that organic matter interacts strongly with mercury, the role of organic matter composition in the formation of methylmercury in aquatic systems remains poorly understood. Here we show that phytoplankton-derived organic compounds enhance mercury methylation rates in boreal lake sediments through an overall increase of bacterial activity. Accordingly, in situ mercury methylation defines methylmercury levels in lake sediments strongly influenced by planktonic blooms. In contrast, sediments dominated by terrigenous organic matter inputs have far lower methylation rates but higher concentrations of methylmercury, suggesting that methylmercury was formed in the catchment and imported into lakes. Our findings demonstrate that the origin and molecular composition of organic matter are critical parameters to understand and predict methylmercury formation and accumulation in boreal lake sediments.

  12. Molecular composition of organic matter controls methylmercury formation in boreal lakes

    PubMed Central

    Bravo, Andrea G.; Bouchet, Sylvain; Tolu, Julie; Björn, Erik; Mateos-Rivera, Alejandro; Bertilsson, Stefan

    2017-01-01

    A detailed understanding of the formation of the potent neurotoxic methylmercury is needed to explain the large observed variability in methylmercury levels in aquatic systems. While it is known that organic matter interacts strongly with mercury, the role of organic matter composition in the formation of methylmercury in aquatic systems remains poorly understood. Here we show that phytoplankton-derived organic compounds enhance mercury methylation rates in boreal lake sediments through an overall increase of bacterial activity. Accordingly, in situ mercury methylation defines methylmercury levels in lake sediments strongly influenced by planktonic blooms. In contrast, sediments dominated by terrigenous organic matter inputs have far lower methylation rates but higher concentrations of methylmercury, suggesting that methylmercury was formed in the catchment and imported into lakes. Our findings demonstrate that the origin and molecular composition of organic matter are critical parameters to understand and predict methylmercury formation and accumulation in boreal lake sediments. PMID:28181492

  13. Molecular composition of organic matter controls methylmercury formation in boreal lakes.

    PubMed

    Bravo, Andrea G; Bouchet, Sylvain; Tolu, Julie; Björn, Erik; Mateos-Rivera, Alejandro; Bertilsson, Stefan

    2017-02-09

    A detailed understanding of the formation of the potent neurotoxic methylmercury is needed to explain the large observed variability in methylmercury levels in aquatic systems. While it is known that organic matter interacts strongly with mercury, the role of organic matter composition in the formation of methylmercury in aquatic systems remains poorly understood. Here we show that phytoplankton-derived organic compounds enhance mercury methylation rates in boreal lake sediments through an overall increase of bacterial activity. Accordingly, in situ mercury methylation defines methylmercury levels in lake sediments strongly influenced by planktonic blooms. In contrast, sediments dominated by terrigenous organic matter inputs have far lower methylation rates but higher concentrations of methylmercury, suggesting that methylmercury was formed in the catchment and imported into lakes. Our findings demonstrate that the origin and molecular composition of organic matter are critical parameters to understand and predict methylmercury formation and accumulation in boreal lake sediments.

  14. Levels of cadmium and mercury in the hair of Atlantic walruses (Odobenus rosmarus rosmarus) from Svalbard, Norway

    SciTech Connect

    Wiig, O.; Renzoni, A.; Gjertz, I.

    1999-08-01

    Hair samples of 15 adult male Atlantic walruses (Odobenus rosmarus rosmarus) collected from anesthetized individuals at Svalbard, Norway, were analyzed for cadmium and total mercury. The mean level of cadmium was 0.860 {+-} 0.321 {micro}g/g dry weight and the mean level of mercury was 0.235 {+-} 0.100 {micro}g/g dry weight. Levels of cadmium and mercury in hair of walruses from other areas are not known. Both cadmium and mercury levels in hair of walruses from Svalbard are relatively low compared to the levels found in the hair of other marine mammal species. It has been documented from a number of marine species, including marine mammals such as ringed seals and polar bears, that both cadmium and mercury levels of Svalbard are lower than in other areas. It is uncertain as to what degree levels in hair reflect levels in internal organs in walruses. In rare and highly endangered species or populations tissue samples can be difficult to collect. In walruses, it is possible to collect hair from anesthetized individuals or at the haul-out sites during molt, to monitor heavy metal levels of the population.

  15. Levels and risk factors of antimony contamination in human hair from an electronic waste recycling area, Guiyu, China.

    PubMed

    Huang, Yue; Ni, Wenqing; Chen, Yaowen; Wang, Xiaoling; Zhang, Jingwen; Wu, Kusheng

    2015-05-01

    The primitive electronic waste (e-waste) recycling has brought a series of environmental pollutants in Guiyu, China. Antimony is one of the important metal contaminants and has aroused the global concerns recently. We aimed to investigate concentrations of antimony in human hair from Guiyu and compared them with those from a control area where no e-waste recycling exists, and assessed the potential risk factors. A total of 205 human hair samples from Guiyu and 80 samples from Jinping were collected for analysis. All volunteers were asked to complete a questionnaire including socio-demographic characteristics and other possible factors related to hair antimony exposure. The concentrations of hair antimony were analyzed using atomic absorption spectrophotometer. Our results indicated that the level of hair antimony in volunteers from Guiyu (median, 160.78; range, 6.99-4412.59 ng/g) was significantly higher than those from Jinping (median, 61.74; range, 2.98-628.43 ng/g). The residents who engaged in e-waste recycling activities in Guiyu had higher hair antimony concentrations than others (P < 0.001). There was no significant difference of hair antimony concentrations among different occupation types in e-waste recycling. Multiple stepwise regression analysis indicated that hair antimony concentrations were associated with education level (β = -0.064), the time of residence in Guiyu (β = 0.112), living house also served as e-waste workshop (β = 0.099), the work related to e-waste (β = 0.169), and smoking (β = 0.018). The elevated hair antimony concentrations implied that the residents in Guiyu might be at high risk of antimony contamination, especially the e-waste recycling workers. Work related to e-waste recycling activities and long-time residence in Guiyu contributed to the high hair antimony exposure.

  16. Benchmark concentrations for methylmercury obtained from the Seychelles Child Development Study.

    PubMed Central

    Crump, K S; Van Landingham, C; Shamlaye, C; Cox, C; Davidson, P W; Myers, G J; Clarkson, T W

    2000-01-01

    Methylmercury is a neurotoxin at high exposures, and the developing fetus is particularly susceptible. Because exposure to methylmercury is primarily through fish, concern has been expressed that the consumption of fish by pregnant women could adversely affect their fetuses. The reference dose for methylmercury established by the U.S. Environmental Protection Agency was based on a benchmark analysis of data from a poisoning episode in Iraq in which mothers consumed seed grain treated with methylmercury during pregnancy. However, exposures in this study were short term and at much higher levels than those that result from fish consumption. In contrast, the Agency for Toxic Substances and Disease Registry (ATSDR) based its proposed minimal risk level on a no-observed-adverse-effect level (NOAEL) derived from neurologic testing of children in the Seychelles Islands, where fish is an important dietary staple. Because no adverse effects from mercury were seen in the Seychelles study, the ATSDR considered the mean exposure in the study to be a NOAEL. However, a mean exposure may not be a good indicator of a no-effect exposure level. To provide an alternative basis for deriving an appropriate human exposure level from the Seychelles study, we conducted a benchmark analysis on these data. Our analysis included responses from batteries of neurologic tests applied to children at 6, 19, 29, and 66 months of age. We also analyzed developmental milestones (age first walked and first talked). We explored a number of dose-response models, sets of covariates to include in the models, and definitions of background response. Our analysis also involved modeling responses expressed as both continuous and quantal data. The most reliable analyses were considered to be represented by 144 calculated lower statistical bounds on the benchmark dose (BMDLs; the lower statistical bound on maternal mercury hair level corresponding to an increase of 0.1 in the probability of an adverse response

  17. Levels of Hair Ethyl Glucuronide in Patients with Decreased Kidney Function: Possibility of Misclassification of Social Drinkers.

    PubMed

    Fosen, Jan Toralf; Morini, Luca; Sempio, Cristina; Ganss, Rudiger; Mørland, Jørg; Høiseth, Gudrun

    2016-03-01

    The use of hair ethyl glucuronide (EtG) levels as a biomarker for chronic high intake of ethanol (EtOH) is increasing, and misclassification of alcohol consumption may have large implications for the patient. The aim of this study was to compare levels of hair EtG in patients with reduced kidney function to levels seen in a comparable control group and to investigate whether the hair EtG levels among kidney failure patients who are social drinkers may lead to a false-positive diagnosis of heavy drinking. A total of 41 patients with reduced kidney function and 42 healthy volunteers were included in the study. Both patients and the healthy volunteers reported moderate alcohol intake. The levels of EtG in hair (corrected for estimated daily intake of EtOH [EDI]) were compared between the 2 groups. There was no significant difference between the groups regarding EDI. Despite this, there were significant higher levels of hair EtG (corrected for EDI) in the patient group compared to the control group (p < 0.001). Eight subjects (20%) in the patient group showed EtG levels in hair above 30 pg/mg, in contrast to no subjects among healthy volunteers (p = 0.002). In the patient group, there was significant correlation between levels of EtG in hair and both estimated glomerulus filtration rate and serum creatinine levels. This study documents an increased risk of obtaining a false-positive diagnosis of heavy drinking among renal disease patients who are social drinkers. Interpretation of EtG levels in hair among patients with reduced kidney function must be performed with caution. Copyright © 2016 by the Research Society on Alcoholism.

  18. Hair-zinc levels determination in Algerian psoriatics using Instrumental Neutron Activation Analysis (INAA).

    PubMed

    Mansouri, A; Hamidatou Alghem, L; Beladel, B; Mokhtari, O E K; Bendaas, A; Benamar, M E A

    2013-02-01

    Psoriasis is a multifactorial skin disease with an unknown etiology. Zinc has a positive impact on psoriasis. The aim of this study is to determine hair-zinc concentration in Algerian psoriatics. 58 psoriatics and 31 normal controls of both genders were selected. Hair zinc levels were determined using Instrumental Neutron Activation Analysis technique (INAA). Student's t-test and One-Way ANOVA were applied. The average zinc concentration for controls and patients were 152 ± 53 μg/g and 167 ± 52 μg/g respectively. They are not significantly different (p>0.05). Zn concentration for males and females controls and patients were 171±27 μg/g, 151±37 μg/g and 145 ± 59 μg/g, 178 ± 58 μg/g respectively. However, for females we have observed a significant difference (p<0.05).

  19. Background values for essential and toxic elements in children's nails and correlation with hair levels.

    PubMed

    Carneiro, Maria Fernanda Hornos; Grotto, Denise; Batista, Bruno Lemos; Rhoden, Claudia Ramos; Barbosa, Fernando

    2011-12-01

    Human nails are an attractive matrix for assessing environmental exposures to toxic elements as well as the deficiency of essential elements since it is noninvasively collected and can be stored at room temperature. However, reference or baseline levels in nonexposed and healthy populations are not yet established. Then, the aims of this study were (a) to estimate background values for essential and toxic elements in nails from a healthy young population in southern Brazil and (b) to evaluate possible correlations between essential and toxic elements in nails. Furthermore, this report took part of a recent study of background values in the hair of a young population. Thus, correlations between chemical elements in nails and hair were also evaluated. Nails were collected from healthy children (n = 126), and element concentrations were determined by inductively coupled plasma mass spectrometry. This study provides new and reliable reference concentrations for toxic and essential elements in children's nails. The results can be used as reference values for epidemiological or clinical investigations based on trace elements in nails. Additionally, we also showed weak to strong correlations between Cu, Mg, Mn, Se, and Zn levels in nails and hair.

  20. Mercury in hair as an indicator of total body burden

    PubMed Central

    Al-Shahristani, H.; Shihab, K.; Al-Haddad, I. K.

    1976-01-01

    Hair is known to concentrate mercury, and in general the concentration of mercury in hair is proportional to and many times higher than its concentration in the blood. The variation of the mercury concentration in human head hair was used to follow the history of poisoning in people who ingested grain treated with methylmercury. Instrumental neutron activation analysis was used for mercury determination. The initial rising slope of mercury concentration along the hair was proportional to the daily intake of methylmercury per kg of body weight. The ratio of the concentration of methylmercury in human head hair to the average body concentration was found to be about 137. By using this ratio and measuring mercury concentration in hair, the total body burden can be calculated. In the patients studied, the peak body burden ranged from 0.8 to 4.4 mg/kg in cases showing mild symptoms, from 1.5 to 6 mg/kg in cases with moderate symptoms, and from 3 to 12 mg/kg in cases with severe symptoms. The curve of the variation in mercury concentrations along the hair was also used to calculate the biological half-life of methylmercury in man. Forty-eight cases were studied and it was found that the frequency curve (population distribution curve) was grouped into two distinct regions. In about 90% of the population the biological half-life of methylmercury was 35-100 days, and 10% showed high values of 110-120 days. PMID:1086158

  1. Histopathological alterations of juvenile green (Acipenser medirostris) and white sturgeon (Acipenser transmontanus) exposed to graded levels of dietary methylmercury.

    PubMed

    Lee, Jang-Won; Kim, Jae-Won; De Riu, Nicola; Moniello, Giuseppe; Hung, Silas S O

    2012-03-01

    Triplicate groups of juvenile green and white sturgeon (average weight of 30 ± 2 g) were exposed to one of four concentrations of dietary methylmercury (MeHg; 0, 25, 50, and 100 mg MeHg/kg diet) for 8 weeks to determine and compare the sensitivity of the two sturgeon species from a histopathological perspective. After 4- and 8-week exposure, histological changes were examined in the kidney, liver, gill, skeletal muscle, and heart muscle of both species using light microscopy. Marked abnormalities were observed in the kidney and liver of both sturgeon species after each exposure period; the abnormalities showed progressive histological alterations in severity with increasing doses and duration of exposure. Renal lesions included tubular epithelium degeneration and necrosis, renal corpuscular disintegration, and interstitial tissue degeneration. The changes observed in the livers of both sturgeon species were glycogen depletion and vacuolar degeneration. In the gill and skeletal and heart muscle of green and white sturgeon fed MeHg-added diets, mild histological changes were observed but did not show pronounced difference between the two species. Although the lowest observed effect concentration in both species was the 25 mg MeHg/kg diet, the histological changes in the kidney and liver were more pronounced at all treatments groups of green sturgeon than those of white sturgeon. The current results on structural changes of kidney and liver (i.e., more severe glycogen depletion and tubular epithelium degeneration in green sturgeon) confirmed our previous results, in that green sturgeon exhibited a higher mortality, lower growth rate, and lower protein, lipid, and energy contents in their whole body than white sturgeon under the same MeHg exposures.

  2. Serum Vitamin D3 Level in Patients with Female Pattern Hair Loss

    PubMed Central

    Banihashemi, Mahnaz; Nahidi, Yalda; Meibodi, Naser Tayyebi; Jarahi, Lida; Dolatkhah, Mojgan

    2016-01-01

    Background: Female pattern hair loss (FPHL) is the most common cause of alopecia in women, characterized by diffuse nonscarring hair loss in frontal, central, and parietal areas of the scalp. Pathophysiology of FPHL is still not well known, and it is probably a multifactorial genetic trait. FPHL is also observed in women without increased androgen levels, which raises the likelihood of androgen-independent mechanisms and explains the lack of response to antiandrogen treatments in some patients. Vitamin D is a factor that has recently been considered in dealing with these patients. The purpose of this study was to evaluate the serum levels of Vitamin D in patients with FPHL and compare it with healthy controls. Methods: In this case-control study, 45 women with FPHL were evaluated as well as the same number of healthy women matched for age, hours spent under sunlight per day, and body mass index. Serum 25(OH) D3 level was measured using ELISA. Results: 60% of FPHL patients were in 15–30 years old age group with the mean standard deviation (SD) age of 29.11 (7.30) years. In the majority of patients (66.7%), severity of hair loss was Ludwig I. Mean (SD) serum Vitamin D3 level in patient and control group was 13.45 (8.40) and 17.16 (8.96), respectively. T-test showed a significant difference between the two groups in terms of Vitamin D3 serum levels (P = 0.04). Conclusions: This study indicated the correlation between the incidence of FPHL and decreased serum levels of Vitamin D3. It is recommended to evaluate serum Vitamin D3 levels as well as other hormone assays in these patients. PMID:27625563

  3. Serum Vitamin D3 Level in Patients with Female Pattern Hair Loss.

    PubMed

    Banihashemi, Mahnaz; Nahidi, Yalda; Meibodi, Naser Tayyebi; Jarahi, Lida; Dolatkhah, Mojgan

    2016-01-01

    Female pattern hair loss (FPHL) is the most common cause of alopecia in women, characterized by diffuse nonscarring hair loss in frontal, central, and parietal areas of the scalp. Pathophysiology of FPHL is still not well known, and it is probably a multifactorial genetic trait. FPHL is also observed in women without increased androgen levels, which raises the likelihood of androgen-independent mechanisms and explains the lack of response to antiandrogen treatments in some patients. Vitamin D is a factor that has recently been considered in dealing with these patients. The purpose of this study was to evaluate the serum levels of Vitamin D in patients with FPHL and compare it with healthy controls. In this case-control study, 45 women with FPHL were evaluated as well as the same number of healthy women matched for age, hours spent under sunlight per day, and body mass index. Serum 25(OH) D3 level was measured using ELISA. 60% of FPHL patients were in 15-30 years old age group with the mean standard deviation (SD) age of 29.11 (7.30) years. In the majority of patients (66.7%), severity of hair loss was Ludwig I. Mean (SD) serum Vitamin D3 level in patient and control group was 13.45 (8.40) and 17.16 (8.96), respectively. T-test showed a significant difference between the two groups in terms of Vitamin D3 serum levels (P = 0.04). This study indicated the correlation between the incidence of FPHL and decreased serum levels of Vitamin D3. It is recommended to evaluate serum Vitamin D3 levels as well as other hormone assays in these patients.

  4. Levels of five metals in male hair from urban and rural areas of Chongqing, China.

    PubMed

    He, Ming-Jing; Wei, Shi-Qiang; Sun, Yu-Xin; Yang, Ting; Li, Qi; Wang, Deng-Xiang

    2016-11-01

    Heavy metals were measured by flame atomic absorption in male hair from residents in urban and rural areas in Chongqing. The median values of the Cd, Cu, Ni, Pb and Zn were 2.90, 23.9, 9.31, 39.3 and 203 μg/g in urban areas and 0.84, 13.4, 5.56, 14.5 and 169 μg/g in rural area, respectively. The levels of Cd, Ni and Pb both in urban and rural areas lie at the high end of the worldwide figures. The differences in heavy metal distribution pattern indicated that there were more sources of Cd and Pb in urban areas. The levels of Cd were increasing along with the growth of age except for the aged people in urban areas, and no significant relationship was observed between the levels of the heavy metal and the age. It is noticed that the hair of smokers exhibited more heavy metal levels than that of non-smokers both in urban and rural areas. In addition, the hair metal levels of the smokers and non-smokers in urban areas were significantly higher than those in rural area, respectively. Significant pairwise correlations (p < 0.01) were observed among Cd, Cu, Ni and Pb in rural area and only between Cu and Ni and between Pb and Ni in urban areas, indicating the elements in these two areas might originate from different sources. The elevated levels of Cd, Pb and Ni implied that the residents both in urban and rural areas might be at high risk of toxic metal exposure, especially for the children.

  5. Selenium status and hair mercury levels in riverine children from Rondônia, Amazonia.

    PubMed

    Vieira Rocha, Ariana; Cardoso, Bárbara Rita; Cominetti, Cristiane; Bueno, Rafael Barofaldi; de Bortoli, Maritsa Carla; Farias, Luciana Aparecida; Favaro, Déborah Inês Teixeira; Camargo, Luís Marcelo Aranha; Cozzolino, Silvia Maria Franciscato

    2014-01-01

    Riverine communities in Rondônia State are exposed to high selenium (Se) content in their diet because of the high-selenium soils identified in the Amazon. However, the Amazonian population has a high mercury (Hg) exposure because this metal accumulates in the soil. Because children are more vulnerable to Hg toxicity, the aim of this study was to evaluate and correlate Se status and hair Hg levels in riverine children (aged 3-9 y) living in two different locations in Rondônia State: Demarcação area (DA) and Gleba do Rio Preto (GRP). Se levels were assessed using hydride generation quartz tube atomic absorption spectroscopy; total hair Hg levels were assessed using cold vapor atomic absorption spectrometry. Dietary intake was evaluated through a 24-h food record and a food frequency questionnaire. Forty-two children participated in this study. Eighty-four percent of the children from DA showed low plasma Se. Conversely, all children from GRP presented plasma Se levels above the reference values. Forty-five percent of the children from DA presented low erythrocyte levels, and 55% of the children from GRP showed concentration in erythrocyte above the reference values. The mean Se intake was 41.8 μg/d in DA and 179.0 μg/d in GRP. High hair Hg levels were observed in children from both the DA and GRP (3.57 ± 1.86 and 6.24 ± 5.89, respectively). Children from both riverine communities are likely to present altered Se status according to their dietary intake. Additionally, these children are highly exposed to Hg, mainly through fish consumption, and the toxicity of this metal may cause metabolic damage. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Negative Confounding by Essential Fatty Acids in Methylmercury Neurotoxicity Associations

    PubMed Central

    Choi, Anna L; Mogensen, Ulla B.; Bjerve, Kristian S.; Debes, Frodi; Weihe, Pal; Grandjean, Philippe; Budtz-Jørgensen, Esben

    2014-01-01

    Background Methylmercury, a worldwide contaminant of fish and seafood, can cause adverse effects on the developing nervous system. However, long-chain n-3 polyunsaturated fatty acids in seafood provide beneficial effects on brain development. Negative confounding will likely result in underestimation of both mercury toxicity and nutrient benefits unless mutual adjustment is included in the analysis. Methods We examined these associations in 176 Faroese children, in whom prenatal methylmercury exposure was assessed from mercury concentrations in cord blood and maternal hair. The relative concentrations of fatty acids were determined in cord serum phospholipids. Neuropsychological performance in verbal, motor, attention, spatial, and memory functions was assessed at 7 years of age. Multiple regression and structural equation models (SEMs) were carried out to determine the confounder-adjusted associations with methylmercury exposure. Results A short delay recall (in percent change) in the California Verbal Learning Test (CVLT) was associated with a doubling of cord blood methylmercury (−18.9, 95% confidence interval [CI] = −36.3, −1.51). The association became stronger after the inclusion of fatty acid concentrations in the analysis (−22.0, 95% confidence interval [CI] = −39.4, −4.62). In structural equation models, poorer memory function (corresponding to a lower score in the learning trials and short delay recall in CVLT) was associated with a doubling of prenatal exposure to methylmercury after the inclusion of fatty acid concentrations in the analysis (−1.94, 95% CI = −3.39, −0.49). Conclusions Associations between prenatal exposure to methylmercury and neurobehavioral deficits in memory function at school age were strengthened after fatty acid adjustment, thus suggesting that n-3 fatty acids need to be included in analysis of similar studies to avoid underestimation of the associations with methylmercury exposure. PMID:24561639

  7. Methylmercury exposure and neurological outcomes in Taiji residents accustomed to consuming whale meat.

    PubMed

    Nakamura, Masaaki; Hachiya, Noriyuki; Murata, Ken-ya; Nakanishi, Ichiro; Kondo, Tomoyoshi; Yasutake, Akira; Miyamoto, Ken-ichiro; Ser, Ping Han; Omi, Sanae; Furusawa, Hana; Watanabe, Chiho; Usuki, Fusako; Sakamoto, Mineshi

    2014-07-01

    Methylmercury (MeHg) is a major environmental neurotoxicant that causes damage to the central nervous system. In Japan, industrial emission of MeHg has resulted in MeHg intoxication in Minamata and Niigata, the so-called Minamata disease. Humans are exposed to MeHg derived from natural sources, primarily fish and fish predators. Therefore, MeHg continues to be an environmental risk to human health, particularly in susceptible populations that frequently consume substantial amounts of fish or fish predators such as whale. This study aimed to investigate the health effects of MeHg exposure in adults. The subjects were 194 residents (117 males, 77 females; age 20-85 years) who resided in the coastal town of Taiji, the birthplace of traditional whaling in Japan. We analyzed hair for mercury content and performed detailed neurological examinations and dietary surveys. Audiometry, magnetic resonance imaging, and electromyography were performed to diagnose neurological defects. Whole blood mercury and selenium (Se) levels were measured in 23 subjects. The geometric mean of the hair mercury levels was 14.9 μg/g. Twelve subjects revealed hair mercury levels >50 μg/g (NOAEL) set by WHO. Hair mercury levels significantly correlated with daily whale meat intake. These results suggested that residents in Taiji were highly exposed to MeHg by ingesting MeHg-contaminated whale meat. Multivariate regression analysis demonstrated no significant correlations between hair mercury levels and neurological outcomes, whereas some of the findings significantly correlated with age. A significantly positive correlation between whole blood mercury and Se levels was observed and the whole blood mercury/Se molar ratios of all subjects were <1. These findings suggested that sufficient Se intake might be one of causes of the absence of adverse effects of MeHg exposure in this study.

  8. Hair removal.

    PubMed

    Haedersdal, Merete; Haak, Christina S

    2011-01-01

    Hair removal with optical devices has become a popular mainstream treatment that today is considered the most efficient method for the reduction of unwanted hair. Photothermal destruction of hair follicles constitutes the fundamental concept of hair removal with red and near-infrared wavelengths suitable for targeting follicular and hair shaft melanin: normal mode ruby laser (694 nm), normal mode alexandrite laser (755 nm), pulsed diode lasers (800, 810 nm), long-pulse Nd:YAG laser (1,064 nm), and intense pulsed light (IPL) sources (590-1,200 nm). The ideal patient has thick dark terminal hair, white skin, and a normal hormonal status. Currently, no method of lifelong permanent hair eradication is available, and it is important that patients have realistic expectations. Substantial evidence has been found for short-term hair removal efficacy of up to 6 months after treatment with the available systems. Evidence has been found for long-term hair removal efficacy beyond 6 months after repetitive treatments with alexandrite, diode, and long-pulse Nd:YAG lasers, whereas the current long-term evidence is sparse for IPL devices. Treatment parameters must be adjusted to patient skin type and chromophore. Longer wavelengths and cooling are safer for patients with darker skin types. Hair removal with lasers and IPL sources are generally safe treatment procedures when performed by properly educated operators. However, safety issues must be addressed since burns and adverse events do occur. New treatment procedures are evolving. Consumer-based treatments with portable home devices are rapidly evolving, and presently include low-level diode lasers and IPL devices.

  9. Association of hair iron levels with creativity and psychological variables related to creativity

    PubMed Central

    Takeuchi, Hikaru; Taki, Yasuyuki; Sekiguchi, Atsushi; Nouchi, Rui; Kotozaki, Yuka; Nakagawa, Seishu; Miyauchi, Carlos M.; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Hashizume, Hiroshi; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

    2013-01-01

    Creativity generally involves the conception of original and valuable ideas. Previous studies have suggested an association between creativity and the dopaminergic system, and that physical activity facilitates creativity. Iron plays a key role in the dopaminergic system and physical activity. Here, we newly investigated the associations between hair iron levels and creativity, dopamine-related traits and states [novelty seeking, extraversion, and vigor (motivational state)], as well as the physical activity level. In the present study, we addressed this issue by performing a hair mineral analysis to determine iron levels and a behavioral creativity test of divergent thinking and related psychological measures among young adults (254 men, 88 women; mean age 20.79 ± 2.03 years). Iron levels did not show any significant association with creativity but displayed significant positive associations with novelty seeking, extraversion, and physical activity level. These results may be partly congruent with the notion that iron plays a key role in the dopaminergic system and imply that iron is important for traits and physical activity, which facilitate creativity. Future interventional or longitudinal studies are warranted to identify any causal effects. PMID:24385960

  10. The Effect of One Session Low Level Laser Therapy of Extracted Follicular Units on the Outcome of Hair Transplantation

    PubMed Central

    Tabaie, Seyed Mehdi; Berenji Ardestani, Hoda; Azizjalali, Mir Hadi

    2016-01-01

    Introduction: Photobiostimulation with low level laser (LLL) has been used in medicine for a long time and its effects have been shown in many diseases. Some studies have evaluated the effect of LLL on androgenic alopecia. One of the most important limitations of the use of LLL in the treatment of alopecia is the requirement for multiple sessions, which is hardly accepted by patients. This study was conducted to evaluate the effect of the irradiation of extracted follicular hair units by LLL on the outcome of hair transplantation. Methods: We enrolled 10 patients with androgenic alopecia and after screening tests for infections and other diseases, we extracted hair follicular units. The hair units were divided in two groups. One group was irradiated by LLL 20 minutes before transplantation (660 nm, 80 Hz, 100 mW) and the other one was used as control. The containing plates were labeled as A and B and sent to the operation room. The surgeon was unaware of the therapy assigned to the plates and transplanted them randomly on the right or left side of the head. One hundred follicular units on each sides of the scalp were transplanted symmetrically. The follicles on both sides were evaluated at 3 and 6 months of transplantation for hair growth rate by another physician, blinded to the treatment assigned to each side. Results: Ten patient with androgenic alopecia and mean (SD) age of 31.5 (6.6) years (range 25-45 years) completed the study. All patients had 100% hair growth at 3 and 6 months follow-up except one who had hair growth of 20% at three months of transplantation, which changed to 100% at sixth months. There was no significant difference between the groups regarding hair growth (P > 0.8). Conclusion: One session of LLL irradiation has no significant effect on the outcome of transplanted hair follicles. Studies with larger sample size are needed to draw a definite conclusion. PMID:27330694

  11. Is the hair nicotine level a more accurate biomarker of environmental tobacco smoke exposure than urine cotinine?

    PubMed Central

    Al-Delaimy, W; Crane, J; Woodward, A

    2002-01-01

    Study objective: The aim of this study was to compare the two biomarkers of exposure to environmental tobacco smoke (ETS); urine cotinine and hair nicotine, using questionnaires as the standard. Design: A cross sectional study of children consecutively admitted to hospital for lower respiratory illnesses during the period of the study. Settings: Three regional hospitals in the larger Wellington area, New Zealand. Participants: Children aged 3–27 months and admitted to the above hospitals during August 1997 to October 1998. A total of 322 children provided 297 hair samples and 158 urine samples. Main results: Hair nicotine levels were better able to discriminate the groups of children according to their household's smoking habits at home (no smokers, smoke only outside the home, smoke inside the house) than urine cotinine (Kruskall-Wallis; χ2=142.14, and χ2=49.5, respectively (p<0.0001)). Furthermore, hair nicotine levels were more strongly correlated with number of smokers in the house, and the number of cigarettes smoked by parents and other members of the child's households. Hair nicotine was better related to the questionnaire variables of smoking in a multivariate regression model (r2=0.55) than urine cotinine (r2=0.31). Conclusions: In this group of young children, hair nicotine was a more precise biomarker of exposure to ETS than urine cotinine levels, using questionnaire reports as the reference. Both biomarkers indicate that smoking outside the house limits ETS exposure of children but does not eliminate it. PMID:11801622

  12. Hair Mercury Levels Detection in Fishermen from Sicily (Italy) by ICP-MS Method after Microwave-Assisted Digestion

    PubMed Central

    Giangrosso, Giuseppe; Cammilleri, Gaetano; Macaluso, Andrea; Vella, Antonio; D'Orazio, Nicolantonio; Graci, Stefania; Lo Dico, Gianluigi Maria; Galvano, Fabio; Giangrosso, Margherita; Ferrantelli, Vincenzo

    2016-01-01

    A number of ninety-six hair samples from Sicilian fishermen were examined for total mercury detection by an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method. The mercury levels obtained were compared with mercury levels of 96 hair samples from a control group, in order to assess potential exposure to heavy metals of Sicilian fishermen due to fish consumption and closeness to industrial activities. Furthermore, the mercury levels obtained from hair samples were sorted by sampling area in order to verify the possible risks linked to the different locations. The overall mean concentration in the hair of the population of fishermen was 6.45 ± 7.03 μg g−1, with a highest value in a fisherman of Sciacca (16.48 μg g−1). Hair mercury concentration in fishermen group was significantly higher than in control group (p < 0.01). There was no significant difference in hair total mercury concentrations between sampling areas (p > 0.05). The results of this study indicate a greater risk of exposure to mercury in Sicilian fishermen, in comparison to the control population, due to the high consumption of fish and the close relationship with sources of exposure (ports, dumps, etc.). PMID:27127456

  13. Seasonal plasticity of auditory hair cell frequency sensitivity correlates with plasma steroid levels in vocal fish

    PubMed Central

    Rohmann, Kevin N.; Bass, Andrew H.

    2011-01-01

    SUMMARY Vertebrates displaying seasonal shifts in reproductive behavior provide the opportunity to investigate bidirectional plasticity in sensory function. The midshipman teleost fish exhibits steroid-dependent plasticity in frequency encoding by eighth nerve auditory afferents. In this study, evoked potentials were recorded in vivo from the saccule, the main auditory division of the inner ear of most teleosts, to test the hypothesis that males and females exhibit seasonal changes in hair cell physiology in relation to seasonal changes in plasma levels of steroids. Thresholds across the predominant frequency range of natural vocalizations were significantly less in both sexes in reproductive compared with non-reproductive conditions, with differences greatest at frequencies corresponding to call upper harmonics. A subset of non-reproductive males exhibiting an intermediate saccular phenotype had elevated testosterone levels, supporting the hypothesis that rising steroid levels induce non-reproductive to reproductive transitions in saccular physiology. We propose that elevated levels of steroids act via long-term (days to weeks) signaling pathways to upregulate ion channel expression generating higher resonant frequencies characteristic of non-mammalian auditory hair cells, thereby lowering acoustic thresholds. PMID:21562181

  14. Maternal hair selenium levels as a possible long-term nutritional indicator of recurrent pregnancy loss

    PubMed Central

    2013-01-01

    Background Approximately 1% of all couples trying to conceive will suffer from recurrent pregnancy loss (RPL). Nutritional deficiencies have been postulated as a possible cause of RPL and in particular, selenium deficiency has been associated with reproductive failure in animal studies and more recently, in some human studies. This study was undertaken to assess the maternal hair selenium levels in women with RPL without an identified cause and to compare these results with those of women with successful reproductive histories. Methods Twenty four patients with RPL and twenty four control subjects with at least one successful pregnancy and no pregnancy failures, who were matched for age and ethnicity, were recruited. A questionnaire was completed, which included demographic and social information and a dietary history. Hair samples were collected and analyzed for selenium content by inductively coupled plasma mass spectrometry. Results The control subjects had a higher mean income and had completed more years of education compared with the RPL patients. There was no significant difference in the intake of selenium rich foods between the 2 groups. The patients, however, consumed significantly more fruit, cheese, potatoes and chocolate than the controls. The median (range) selenium content was 0.80 ppm (0.19-4.15) and 0.68 ppm (0.43-3.76) in patients and controls respectively (Mann Whitney U test 209.5 p = 0.74). Conclusions While there were significant differences in the 2 groups with regard to resources, education and diet our results show that hair selenium concentrations and dietary selenium intake, were similar in the two groups. Both groups had low levels of this important element. PMID:24148900

  15. Levels of hormones and cytokines associated with growth in Honamlı and native hair goats.

    PubMed

    Devrim, A K; Elmaz, O; Mamak, N; Sudagidan, M

    2015-01-01

    This study was designed to assess alterations of hormone and cytokine levels associated with growth period during puberty in Honamlı goats which were identified as a new goat breed and had one of the highest meat production potential among the other goat breeds in Turkey. Honamlı goats are originated from native hair goats, so parallel studies of sampling and analyzing were conducted also in native hair goats which have moderate meat production. Blood serum samples of Honamlı (n=90) and native hair goats (n=90) were obtained from the pure herds in Korkuteli and Ka districts of Anatolia. Concentrations of growth hormone (GH), myostatin (MSTN), insulin-like growth factor (IGF), growth hormone releasing hormone (GHRH), growth hormone releasing peptide (GHRP), leptin, transforming growth factor-betal (TGF-β1) and vascular endothelial cell growth factor (VEGF) levels were measured by ELISA in each breed in the age groups of 4, 8 and 12 months. The present results indicate interesting correlations among the age groups and all the examined hormone and cytokine parameters exhibited significant (P<0.05 and P<0.001) differences. The parameters investigated were usually begun to increase after 4 months of age in the both breeds and sexes. Therefore, this paper supported the view that the beginning of hormonal alterations of goats could occur at 4th month of age. The results reported here emphasize the primary role played by GH, MSTN, IGF-1, leptin, GHRH, GHRP, TGF-βi and VEGF in the first year growth period of goats.

  16. Maternal hair selenium levels as a possible long-term nutritional indicator of recurrent pregnancy loss.

    PubMed

    Thomas, Viju V; Knight, Robert; Haswell, Stephen J; Lindow, Stephen W; van der Spuy, Zephne M

    2013-10-22

    Approximately 1% of all couples trying to conceive will suffer from recurrent pregnancy loss (RPL). Nutritional deficiencies have been postulated as a possible cause of RPL and in particular, selenium deficiency has been associated with reproductive failure in animal studies and more recently, in some human studies. This study was undertaken to assess the maternal hair selenium levels in women with RPL without an identified cause and to compare these results with those of women with successful reproductive histories. Twenty four patients with RPL and twenty four control subjects with at least one successful pregnancy and no pregnancy failures, who were matched for age and ethnicity, were recruited. A questionnaire was completed, which included demographic and social information and a dietary history. Hair samples were collected and analyzed for selenium content by inductively coupled plasma mass spectrometry. The control subjects had a higher mean income and had completed more years of education compared with the RPL patients. There was no significant difference in the intake of selenium rich foods between the 2 groups. The patients, however, consumed significantly more fruit, cheese, potatoes and chocolate than the controls. The median (range) selenium content was 0.80 ppm (0.19-4.15) and 0.68 ppm (0.43-3.76) in patients and controls respectively (Mann Whitney U test 209.5 p = 0.74). While there were significant differences in the 2 groups with regard to resources, education and diet our results show that hair selenium concentrations and dietary selenium intake, were similar in the two groups. Both groups had low levels of this important element.

  17. Methylmercury (MeHg)

    Integrated Risk Information System (IRIS)

    Methylmercury ( MeHg ) ; CASRN 22967 - 92 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  18. Marine biogeochemistry: Methylmercury manufacture

    NASA Astrophysics Data System (ADS)

    Cossa, Daniel

    2013-10-01

    The neurotoxin methylmercury can accumulate in marine food webs, contaminating seafood. An analysis of the isotopic composition of fish in the North Pacific suggests that much of the mercury that enters the marine food web originates from low-oxygen subsurface waters.

  19. Relationships between hair melanization, glutathione levels, and senescence in wild boars.

    PubMed

    Galván, Ismael; Alonso-Alvarez, Carlos; Negro, Juan J

    2012-01-01

    The synthesis of melanins, which are the most common animal pigments, is influenced by glutathione (GSH), a key intracellular antioxidant. At high GSH levels, pheomelanin (the lightest melanin form) is produced, whereas production of eumelanin (the darkest melanin form) does not require GSH. Oxidative damage typically increases with age, and age-related decreases in GSH have accordingly been found in diverse organisms. Therefore, there should be positive associations between the capacity to produce eumelanic traits, GSH levels, and senescence, whereas there should be negative associations between the capacity to produce pheomelanic traits, GSH levels, and senescence. We explored this hypothesis in a free-ranging population of wild boars Sus scrofa of different ages. As expected from the fact that pheomelanogenesis consumes GSH, levels of this antioxidant in muscle tended to be negatively related to pheomelanization and positively related to eumelanization in pelage, and the degree of pelage pheomelanization was positively related to oxidative damage as reflected by levels of thiobarbituric-acid-reactive substances (TBARS), which is consistent with the hypothesis that pheomelanin synthesis has physiological costs. In our cross-sectional sample, GSH levels did not show senescence effects, and we did not detect senescence effects in pelage melanization. Prime body condition and low TBARS levels were also associated with hair graying, which is attributable to a loss of melanin produced by oxidative stress, thus raising the possibility that hair graying constitutes a signal of resistance to oxidative stress in wild boars. Our results suggest that the degree of melanization is linked to GSH levels in wild boars and that their antioxidant damage shows senescence effects.

  20. Hair cosmetics.

    PubMed

    O'Donoghue, M N

    1987-07-01

    Porosity, elasticity, and texture influence the hair's ability to be changed. The types of color--temporary, gradual, natural, semipermanent, and permanent--depend upon the size of the "coloring" molecule to determine whether they penetrate the cortex (permanent) or precipitate on the cuticle. Different types of hair--thick or coarse, fine or thin--have varying affinity for different products and coloring/waving methods. Damaged hair is treated differently from hair with healthy, less porous shafts. Because so many people have color-treated hair today, dermatologists should be aware of all the latest changes and improvements, in order to assist patients with damaged or congenitally deformed hair. Acid-based permanents are becoming the most commonly used. Daily care with shampooing and conditioning has attained its most sophisticated level with the use of anionic and cationic surfactants in all hair-care products. It is also important for the dermatologist to be aware of what help is available for his or her patients. Cosmetic companies are eager to help any patient with severe problems with texture, dullness, over-fine or congenitally defective hair. The physician should send the patient with a severe problem directly to the nearest company headquarters or major city office to have a hair analysis, and receive suggestions from the experts of that company. For patients with moderate to mild problems, the dermatologist should be able to recommend three or four good salons in the local area with which he or she is familiar. Our main goal as physicians is to take care of the entire patient and to enable him or her to have a good self-image.

  1. microRNA level is raised in the hair shafts of patients with dematomyositis in comparison with normal subjects and patients with scleroderma.

    PubMed

    Inoue, Minami; Jinnin, Masatoshi; Wang, Zhongzhi; Nakamura, Kayo; Inoue, Kuniko; Ichihara, Asako; Moriya, Chikako; Sakai, Keisuke; Fukushima, Satoshi; Ihn, Hironobu

    2016-07-01

    The diagnosis of dermatomyositis is sometimes difficult. We tried to evaluate the possibility that levels of Homo sapiens microRNA-214 (hsa-miR-214) in hair roots or hair shafts can be a useful marker of the disease. A single hair root and five pieces of hair shafts were obtained from nine patients with dermatomyositis, 15 normal subjects, and 18 patients with scleroderma before treatment. RNAs were purified from the hair roots and hair shafts using commercially available kits. cDNA was synthesized from the RNA, and miR-214 levels were measured with quantitative real-time polymerase chain reaction. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of hair microRNA levels. The levels of miR-214 in hair shafts of patients with dermatomyositis were significantly higher than those of normal subjects and patients with scleroderma. By receiver operator curve analysis of hair shaft miR-214 levels to distinguish patients with dermatomyositis from normal subjects, the area under the curve was 0.90. The duration between symptom onset and the first visit to the hospital was significantly shorter in patients with elevated hair shafts miR-214 levels, suggesting that they have more severe subjective symptoms. On the other hand, we could not find significant differences in hair root miR-214 levels among normal subjects and patients with dermatomyositis and scleroderma. Hair shaft miR-214 levels are useful for diagnosis and evaluating the disease severity of dermatomyositis. Hair microRNA levels may have potential to be a novel and less invasive biomarker. © 2015 The International Society of Dermatology.

  2. Elevated Hair Cortisol Levels among Heroin Addicts on Current Methadone Maintenance Compared to Controls.

    PubMed

    Yang, Jin; Li, Jifeng; Xu, Guanyi; Zhang, Jing; Chen, Zheng; Lu, Zuhong; Deng, Huihua

    2016-01-01

    Whether methadone maintenance treatment (MMT) can improve the basal function of the hypothalamic-pituitary-adrenal (HPA) axis, which is suppressed by long-term heroin consumption, is a matter of debate. The stress state and depression and anxiety symptoms may affect the basal activity of the HPA axis in MMT patients. However, the effect of psychological factors on HPA activity was not simultaneously controlled in previous studies. This study investigated differences in HPA basal activity between MMT patients and controls using psychological variables as covariates. The participants included 52 MMT patients and 41 age-matched, non-heroin-dependent controls. Psychological states were self-reported with the Perceived Stress Scale, Self-Rating Depression Scale and Self-Rating Anxiety Scale. The hair cortisol level was adopted as a biomarker of HPA basal activity and was determined with liquid chromatography tandem mass spectrometry. The results revealed that MMT patients had significantly higher hair cortisol levels than the controls (p<0.05), but the difference was not significant (p>0.05) when the perceived stress, depression and anxiety scores were used as covariates. We concluded that patients with long-term MMT showed higher basal activity of the HPA axis. The high chronic stress state and increase in depression and anxiety symptoms may mask the suppression effect of methadone on the HPA activity.

  3. Elevated Hair Cortisol Levels among Heroin Addicts on Current Methadone Maintenance Compared to Controls

    PubMed Central

    Yang, Jin; Li, Jifeng; Xu, Guanyi; Zhang, Jing; Chen, Zheng; Lu, Zuhong; Deng, Huihua

    2016-01-01

    Whether methadone maintenance treatment (MMT) can improve the basal function of the hypothalamic–pituitary–adrenal (HPA) axis, which is suppressed by long-term heroin consumption, is a matter of debate. The stress state and depression and anxiety symptoms may affect the basal activity of the HPA axis in MMT patients. However, the effect of psychological factors on HPA activity was not simultaneously controlled in previous studies. This study investigated differences in HPA basal activity between MMT patients and controls using psychological variables as covariates. The participants included 52 MMT patients and 41 age-matched, non-heroin-dependent controls. Psychological states were self-reported with the Perceived Stress Scale, Self-Rating Depression Scale and Self-Rating Anxiety Scale. The hair cortisol level was adopted as a biomarker of HPA basal activity and was determined with liquid chromatography tandem mass spectrometry. The results revealed that MMT patients had significantly higher hair cortisol levels than the controls (p<0.05), but the difference was not significant (p>0.05) when the perceived stress, depression and anxiety scores were used as covariates. We concluded that patients with long-term MMT showed higher basal activity of the HPA axis. The high chronic stress state and increase in depression and anxiety symptoms may mask the suppression effect of methadone on the HPA activity. PMID:27010803

  4. Levels and sources of brominated flame retardants in human hair from urban, e-waste, and rural areas in South China.

    PubMed

    Zheng, Jing; Luo, Xiao-Jun; Yuan, Jian-Gang; Wang, Jing; Wang, Yu-Tao; Chen, Shen-Jun; Mai, Bi-Xian; Yang, Zhong-Yi

    2011-12-01

    Human hair and indoor dust from urban, e-waste, and rural areas in south China were collected and analyzed for brominated flame retardants (BFRs). BFRs concentrations in hair from occupational e-waste recycling workers were higher than those from non-occupational exposed residents in other sampling areas. Polybrominated diphenyl ethers (PBDEs) and decabromodiphenyl ethane (DBDPE) are two major BFRs in hair samples. The PBDE congener profiles in hair from the e-waste area are different from those from urban and rural areas with relatively higher contribution of lower brominated congeners. DBDPE, instead of BDE209, has become the major BFR in non-e-waste recycling areas. Significant correlations were found between hair level and dust level for DBDPE and BTBPE but not for PBDEs. The different PBDE congener profiles between dust and hair may suggest that exogenous exposure to the PBDE adsorbed on dust is not a major source of hair PBDEs.

  5. Mercury contamination in fish and human hair from Hainan Island, South China Sea: Implication for human exposure.

    PubMed

    Liu, Jin-Ling; Xu, Xiang-Rong; Yu, Shen; Cheng, Hefa; Peng, Jia-Xi; Hong, Yi-Guo; Feng, Xin-Bin

    2014-11-01

    Hair has long been recognized as a good biomarker for human exposure to Hg. The mercury concentrations in 14 species of marine fish and hair samples from 177 coastal residents in Hainan, South China Sea were investigated to assess the status of mercury exposure associated with marine fish consumption. Concentrations of total Hg (THg) and methylmercury (MeHg) in the fish muscles were 0.094 ± 0.008 and 0.066 ± 0.006 μg/gww, respectively, which were far below the limit considered safe for consumption (0.5 μg/g). The average THg concentrations in hair of adults (1.02 ± 0.92 μg/g) were lower than the provisional tolerable weekly intake (PTWI) level of 2.2 μg/g. However, 23.7% of children had a hair THg level exceeding the RfD level of 1μg/g, indicating a great risk of Hg exposure to children via fish consumption. The concentration of THg in hair was significantly correlated with fish consumption but not with gender-specific fish intake. With higher fish consumption frequency, the fishermen had significantly elevated hair Hg levels compared to the students and the other general public, who had similar hair THg levels but different fish consumption patterns, indicating the existence of other sources of Hg exposure to the residents of Hainan Island.

  6. Photodegradation of methylmercury in lakes

    NASA Astrophysics Data System (ADS)

    Seller, P.; Kelly, C. A.; Rudd, J. W. M.; Machutchon, A. R.

    1996-04-01

    METHYLMERCURY can accumulate in fish to concentrations that threaten human health1. Fish methylmercury concentrations are high in many reservoirs2 and acidic lakes3, and also in many remote lakes4,5-a fact that may be related to increased atmospheric deposition of anthropogenically mobilized mercury during the past few decades6. Although sources of methylmercury to lakes and reservoirs are known7, in-lake destruction has not been demonstrated to occur at the low concentrations found in most water bodies. Here we report in situ incubations of lake water that show that methylmercury is decomposed by photo- degradation in surface waters. This process is abiotic and the rate is first-order with respect to methylmercury concentration and the intensity of solar radiation. In our study lake, the calculated annual rates of methylmercury photodegradation are almost double the estimated external inputs of methylmercury from rain, snow, streamflow and land runoff, implying the existence of a large source of methylmercury from bottom sediments. Photodegradation could also be an important process in the mercury cycle of other aquatic systems. This discovery fundamentally changes our understanding of aquatic mercury cycling, and challenges the long-accepted view that microbial demethylation dominates methylmercury degradation in natural fresh waters.

  7. A molecular level prototype for mechanoelectrical transducer in mammalian hair cells

    PubMed Central

    Park, Jinkyoung

    2013-01-01

    The mechanoelectrical transducer (MET) is a crucial component of mammalian auditory system. The gating mechanism of the MET channel remains a puzzling issue, though there are many speculations, due to the lack of essential molecular building blocks. To understand the working principle of mammalian MET, we propose a molecular level prototype which constitutes a charged blocker, a realistic ion channel and its surrounding membrane. To validate the proposed prototype, we make use of a well-established ion channel theory, the Poisson-Nernst-Planck equations, for three-dimensional (3D) numerical simulations. A wide variety of model parameters, including bulk ion concentration, applied external voltage, blocker charge and blocker displacement, are explored to understand the basic function of the proposed MET prototype. We show that our prototype prediction of channel open probability in response to blocker relative displacement is in a remarkable accordance with experimental observation of rat cochlea outer hair cells. Our results appear to suggest that tip links which connect hair bundles gate MET channels. PMID:23625048

  8. Relationship between mercury levels in hair and fish consumption in a population living near a hydroelectric tropical dam.

    PubMed

    Marrugo-Negrete, José Luis; Ruiz-Guzmán, Javier Alonso; Díez, Sergi

    2013-02-01

    In the present study, total mercury (T-Hg) concentrations were assessed in human hair samples (n = 76) and fish muscle (n = 33) collected at Urrá dam, upstream Sinú river, northwestern Colombia. Based on interviews with study participants, weekly intakes of total mercury (WIT-Hg) and methylmercury (WIMeHg) by fish consumption were also estimated. T-Hg concentrations in hair samples ranged from 0.40 to 24.56 μg/g dw. The highest concentrations were recorded in children (CH) (2-15 years old, n = 24) with significant differences (p < 0.05) with respect to women of childbearing age (WCHA) (16-49 years old, n = 29) and the rest of the population (RP) (n = 23), which were not significantly different. The highest T-Hg concentrations in muscle tissue were recorded in the carnivorous fish (0.65-2.25 μg/g wet weight, ww), with significant differences (p < 0.05) compared to non-carnivorous fish (0.16-0.54 μg/g ww). WIT-Hg recorded the highest values in CH (2.18-50.41 μg/kg/week), with significant differences (p < 0.05) with respect to WCHA (2.02-23.54 μg/kg/week) and RP (1.09-24.71 μg/kg/week), which were not significantly different. Correlation analysis showed a significant relationship between weekly fish consumption and hair T-Hg in CH (r = 0.37, p < 0.05) and WCHA (r = 0.44, p < 0.05). This association was also observed with the number of days per week with fish consumption in CH (r = 0.37, p < 0.05) and WCHA (r = 0.45, p < 0.05). These results suggest that Hg exposure in people inhabiting the Urrá dam should be carefully monitored, particularly in vulnerable groups such as CH and WCHA.

  9. Mercury accumulation in mallards fed methylmercury with or without added DDE

    USGS Publications Warehouse

    Heinz, G.H.

    1987-01-01

    Adult female mallards (Anas platyrhynchos) were fed a control diet or diets containing 1 ppm methylmercury chloride, 5 ppm methylmercury chloride, 1 ppm methylmercury chloride plus 5 ppm DDE, or 5 ppm methylmercury chloride plus 5 ppm DDE. The presence of DDE in the diet did not affect retention of mercury in breast muscle or eggs. There was a good correlation between the levels of mercury in the breast muscle of females and their eggs, and this correlation was unaffected by the presence of DDE in the diet. This correlation suggests that one could predict mercury levels in female mallards in the field when only eggs have been collected and vice versa.

  10. Quantitative analysis of the endogenous GHB level in the hair of the Chinese population using GC/MS/MS.

    PubMed

    Shi, Yan; Cui, Xiaopei; Shen, Min; Xiang, Ping

    2016-04-01

    Endogenous production complicates interpretation when gamma-hydroxybutyrate (GHB) is measured in hair for forensic purposes. A method capable of quantifying the endogenous concentration of GHB in human head hair was developed and validated using GC/MS/MS. Hair was digested under alkaline conditions (1 mol/L NaOH, 90 °C 10 min), and GHB-d6 was used as an internal standard. Before derivatization with BSTFA and ethyl acetate, a liquid-liquid extraction with ethyl acetate under acidic conditions was performed. GHB-TMS derivatives were detected using GC/MS/MS in the multiple-reaction monitoring mode. This method exhibited good linearity (y = 0.018x + 0.038, R(2) = 0.9998), and the limit of detection was 0.02 ng/mg. The extraction recoveries were more than 60%, and the inter-day and intra-day relative standard deviations (RSD) were less than 15%. This method has been applied for the analysis of the endogenous GHB in hair samples from 66 drug-free Chinese donors. The mean measured concentration for 0-3 cm hair was 1.93 ± 1.40 ng/mg (n = 66), and extreme values were in the range of 0.28-4.91 ng/mg. The mean male endogenous GHB level was 2.95 ng/mg (0.92-4.91 ng/mg, n = 35), while the mean female level was 0.77 ng/mg (0.28-1.95 ng/mg, n = 31). This method was applied to a forensic case for the determination of GHB in hair samples but it is hard to make a reasonable "cut off" in hair. The solution is to use each subject as his own control.

  11. Low level postnatal methylmercury exposure in vivo alters developmental forms of short-term synaptic plasticity in the visual cortex of rat

    SciTech Connect

    Dasari, Sameera; Yuan, Yukun

    2009-11-01

    Methylmercury (MeHg) has been previously shown to affect neurotransmitter release. Short-term synaptic plasticity (STP) is primarily related to changes in the probability of neurotransmitter release. To determine if MeHg affects STP development, we examined STP forms in the visual cortex of rat following in vivo MeHg exposure. Neonatal rats received 0 (0.9% NaCl), 0.75 or 1.5 mg/kg/day MeHg subcutaneously for 15 or 30 days beginning on postnatal day 5, after which visual cortical slices were prepared for field potential recordings. In slices prepared from rats treated with vehicle, field excitatory postsynaptic potentials (fEPSPs) evoked by paired-pulse stimulation at 20-200 ms inter-stimulus intervals showed a depression (PPD) of the second fEPSP (fEPSP2). PPD was also seen in slices prepared from rats after 15 day treatment with 0.75 or 1.5 mg/kg/day MeHg. However, longer duration treatment (30 days) with either dose of MeHg resulted in paired-pulse facilitation (PPF) of fEPSP2 in the majority of slices examined. PPF remained observable in slices prepared from animals in which MeHg exposure had been terminated for 30 days after completion of the initial 30 day MeHg treatment, whereas slices from control animals still showed PPD. MeHg did not cause any frequency- or region-preferential effect on STP. Manipulations of [Ca{sup 2+}]{sub e} or application of the GABA{sub A} receptor antagonist bicuculline could alter the strength and polarity of MeHg-induced changes in STP. Thus, these data suggest that low level postnatal MeHg exposure interferes with the developmental transformation of STP in the visual cortex, which is a long-lasting effect.

  12. Mercury and selenium levels, and their molar ratios in several species of commercial shrimp in Japan regarding the health risk of methylmercury exposure.

    PubMed

    Hoang, Van Anh Thi; Sakamoto, Mineshi; Yamamoto, Megumi

    2017-01-01

    The Japanese shrimp industry depends on importing shrimp from other countries. However, little information is available on mercury speciation and selenium (Se) concentrations in commercial shrimp available in Japan. The present study determined the concentrations of total mercury (T-Hg), methylmercury (MeHg), and Se in the muscles (wet weight) of imported and domestic commercial shrimp from Kumamoto and Kagoshima prefectures to obtain information for assessing the risk of MeHg exposure. The median concentrations of T-Hg, MeHg and Se in shrimp imported from three different countries were, respectively: black tiger shrimp (n = 18), 15.8, 14.4, and 415 ng/g; Vannamei shrimp (n = 25), 11.4, 11.2, and 292 ng/g; and white shrimp (n = 26), 26.8, 26.1, and 396 ng/g. There were significant differences in T-Hg and MeHg concentrations between shrimp imported from different countries. The median concentrations of T-Hg, MeHg and Se in shrimp of Japanese origin were, respectively: Shiba shrimp (n = 10), 15.9, 15.0, and 270 ng/g; Kuruma shrimp (n = 10), 79.9, 75.9, and 390 ng/g; and Ashiaka shrimp (n = 10), 36.1, 34.1, and 303 ng/g. The percentages of MeHg in T-Hg were between 90% and 99%, with MeHg levels in the imported and domestic commercial shrimp lower than the Japanese regulation of 300 ng/g for fish. The mean Se/T-Hg molar ratios (16-160) were comparatively higher than those previously reported in fish. Overall, this survey suggests that shrimp commercially available in Japan will not pose a particularly high risk regarding MeHg exposure to consumers.

  13. Methylmercury concentrations in broiler's meat and hen's meat and eggs

    SciTech Connect

    Kambamanoli-Dimou, A. ); Kilikidis, S.; Kamarianos, A. )

    1989-05-01

    The concentration of mercury in food has been considered to present the greatest toxicological danger to the average citizen. The presence of mercury in foods has been reported in several studies. Much of the research has been carried out on total mercury concentration in foods and not on methylmercury concentration and as it is known methylmercury is the most dangerous form of mercury. Methylmercury, which is highly resistant to biodegradation, can be synthesized from any other form of mercury in the aquatic biosphere, can be bioconcentrated in the aquatic food chain and through fish-meals can be transported and concentrated in animals and their products. Such food chains, together with the various terrestrial food chains would represent a serious risk for man. This study was undertaken to determine the methylmercury levels in broiler's meat, hen's meat and eggs.

  14. Water-level fluctuations influence sediment porewater chemistry and methylmercury production in a flood-control reservoir.

    EPA Science Inventory

    Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluct...

  15. Water-level fluctuations influence sediment porewater chemistry and methylmercury production in a flood-control reservoir.

    EPA Science Inventory

    Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluct...

  16. Minamata disease: methylmercury poisoning in Japan caused by environmental pollution.

    PubMed

    Harada, M

    1995-01-01

    Minamata disease (M. d.) is methylmercury (MeHg) poisoning that occurred in humans who ingested fish and shellfish contaminated by MeHg discharged in waste water from a chemical plant (Chisso Co. Ltd.). It was in May 1956, that M. d. was first officially "discovered" in Minamata City, south-west region of Japan's Kyushu Island. The marine products in Minamata Bay displayed high levels of Hg contamination (5.61 to 35.7 ppm). The Hg content in hair of patients, their family and inhabitants of the Shiranui Sea coastline were also detected at high levels of Hg (max. 705 ppm). Typical symptoms of M. d. are as follows: sensory disturbances (glove and stocking type), ataxia, dysarthria, constriction of the visual field, auditory disturbances and tremor were also seen. Further, the fetus was poisoned by MeHg when their mothers ingested contaminated marine life (named congenital M. d.). The symptom of patients were serious, and extensive lesions of the brain were observed. While the number of grave cases with acute M. d. in the initial stage was decreasing, the numbers of chronic M. d. patients who manifested symptoms gradually over an extended period of time was on the increase. For the past 36 years, of the 2252 patients who have been officially recognized as having M. d., 1043 have died. This paper also discusses the recent remaining problems.

  17. Aggressive behavior and hair cortisol levels in captive Dorcas gazelles (Gazella dorcas) as animal-based welfare indicators.

    PubMed

    Salas, Marina; Temple, Déborah; Abáigar, Teresa; Cuadrado, Mariano; Delclaux, Maria; Enseñat, Conrad; Almagro, Vanessa; Martínez-Nevado, Eva; Quevedo, Miguel Ángel; Carbajal, Annaïs; Tallo-Parra, Oriol; Sabés-Alsina, Maria; Amat, Marta; Lopez-Bejar, Manel; Fernández-Bellon, Hugo; Manteca, Xavier

    2016-11-01

    Ensuring welfare in captive wild animal populations is important not only for ethical and legal reasons, but also to maintain healthy individuals and populations. An increased level of social behaviors such as aggression can reduce welfare by causing physical damage and chronic stress to animals. Recently, cortisol in hair has been advanced as a non-invasive indicator to quantify long-lasting stress in many species. The sensitivity of social behavior and hair cortisol concentration was evaluated in several groups of dorcas gazelles (Gazella dorcas). Four different groups of gazelles from three different zoos were observed and the expression of intra-specific affiliative and negative social behaviors was assessed across the different groups. Hair samples were taken from sub-groups of animals and analyzed for cortisol concentrations. Significant differences between groups of dorcas gazelles were found in frequency of negative social behavior and hair cortisol concentration. Despite the low sample size, these two parameters had a positive Spearman correlation coefficient (rs  = +0.80, P = 0.20). These results suggest that hair cortisol levels are sensitive to differences in the social structure of dorcas gazelles. Zoo Biol. 35:467-473, 2016. © 2016 Wiley Periodicals, Inc.

  18. Low-level laser treatment accelerated hair regrowth in a rat model of chemotherapy-induced alopecia (CIA).

    PubMed

    Wikramanayake, Tongyu Cao; Villasante, Alexandra C; Mauro, Lucia M; Nouri, Keyvan; Schachner, Lawrence A; Perez, Carmen I; Jimenez, Joaquin J

    2013-05-01

    Chemotherapy-induced alopecia (CIA) is one of the most distressing side effects of antineoplastic chemotherapy for which there is no effective interventional approach. A low-level laser (LLL) device, the HairMax LaserComb®, has been cleared by the FDA to treat androgenetic alopecia. Its effects may be extended to other settings; we have demonstrated that LaserComb treatment induced hair regrowth in a mouse model for alopecia areata. In the current study, we tested whether LLL treatment could promote hair regrowth in a rat model for CIA. Chemotherapy agents cyclophosphamide, etoposide, or a combination of cyclophosphamide and doxorubicin were administered in young rats to induce alopecia, with or without LLL treatment. As expected, 7-10 days later, all the rats developed full body alopecia. However, rats receiving laser treatment regrew hair 5 days earlier than rats receiving chemotherapy alone or sham laser treatment (with the laser turned off). The accelerated hair regrowth in laser-treated rats was confirmed by histology. In addition, LLL treatment did not provide local protection to subcutaneously injected Shay chloroleukemic cells. Taken together, our results demonstrated that LLL treatment significantly accelerated hair regrowth after CIA without compromising the efficacy of chemotherapy in our rat model. Our results suggest that LLL should be explored for the treatment of CIA in clinical trials because LLL devices for home use (such as the HairMax LaserComb®) provide a user-friendly and noninvasive approach that could be translated to increased patient compliance and improved efficacy.

  19. A Novel Atoh1 “Self-Terminating” Mouse Model Reveals the Necessity of Proper Atoh1 Level and Duration for Hair Cell Differentiation and Viability

    PubMed Central

    Pan, Ning; Jahan, Israt; Kersigo, Jennifer; Duncan, Jeremy S.; Kopecky, Benjamin; Fritzsch, Bernd

    2012-01-01

    Atonal homolog1 (Atoh1) is a bHLH transcription factor essential for inner ear hair cell differentiation. Targeted expression of Atoh1 at various stages in development can result in hair cell differentiation in the ear. However, the level and duration of Atoh1 expression required for proper hair cell differentiation and maintenance remain unknown. We generated an Atoh1 conditional knockout (CKO) mouse line using Tg(Atoh1-cre), in which the cre expression is driven by an Atoh1 enhancer element that is regulated by Atoh1 protein to “self-terminate” its expression. The mutant mice show transient, limited expression of Atoh1 in all hair cells in the ear. In the organ of Corti, reduction and delayed deletion of Atoh1 result in progressive loss of almost all the inner hair cells and the majority of the outer hair cells within three weeks after birth. The remaining cells express hair cell marker Myo7a and attract nerve fibers, but do not differentiate normal stereocilia bundles. Some Myo7a-positive cells persist in the cochlea into adult stages in the position of outer hair cells, flanked by a single row of pillar cells and two to three rows of disorganized Deiters cells. Gene expression analyses of Atoh1, Barhl1 and Pou4f3, genes required for survival and maturation of hair cells, reveal earlier and higher expression levels in the inner compared to the outer hair cells. Our data show that Atoh1 is crucial for hair cell mechanotransduction development, viability, and maintenance and also suggest that Atoh1 expression level and duration may play a role in inner vs. outer hair cell development. These genetically engineered Atoh1 CKO mice provide a novel model for establishing critical conditions needed to regenerate viable and functional hair cells with Atoh1 therapy. PMID:22279587

  20. FISH CONSUMPTION, METHYLMERCURY, AND HUMAN HEART DISEASE.

    SciTech Connect

    LIPFERT, F.W.; SULLIVAN, T.M.

    2005-09-21

    Environmental mercury continues to be of concern to public health advocates, both in the U.S. and abroad, and new research continues to be published. A recent analysis of potential health benefits of reduced mercury emissions has opened a new area of public health concern: adverse effects on the cardiovascular system, which could account for the bulk of the potential economic benefits. The authors were careful to include caveats about the uncertainties of such impacts, but they cited only a fraction of the applicable health effects literature. That literature includes studies of the potentially harmful ingredient (methylmercury, MeHg) in fish, as well as of a beneficial ingredient, omega-3 fatty acids or ''fish oils''. The U.S. Food and Drug Administration (FDA) recently certified that some of these fat compounds that are primarily found in fish ''may be beneficial in reducing coronary heart disease''. This paper briefly summarizes and categorizes the extensive literature on both adverse and beneficial links between fish consumption and cardiovascular health, which are typically based on studies of selected groups of individuals (cohorts). Such studies tend to comprise the ''gold standard'' of epidemiology, but cohorts tend to exhibit a great deal of variability, in part because of the limited numbers of individuals involved and in part because of interactions with other dietary and lifestyle considerations. Note that eating fish will involve exposure to both the beneficial effects of fatty acids and the potentially harmful effects of contaminants like Hg or PCBs, all of which depend on the type of fish but tend to be correlated within a population. As a group, the cohort studies show that eating fish tends to reduce mortality, especially due to heart disease, for consumption rates up to about twice weekly, above which the benefits tend to level off. A Finnish cohort study showed increased mortality risks in the highest fish-consuming group ({approx}3 times

  1. Effect of low-level laser treatment on cochlea hair-cell recovery after ototoxic hearing loss

    NASA Astrophysics Data System (ADS)

    Rhee, Chung-Ku; He, Peijie; Jung, Jae Yun; Ahn, Jin-Chul; Chung, Phil-Sang; Lee, Min Young; Suh, Myung-Whan

    2013-12-01

    The primary cause of hearing loss includes damage to cochlear hair cells. Low-level laser therapy (LLLT) has become a popular treatment for damaged nervous systems. Based on the idea that cochlea hair cells and neural cells are from same developmental origin, the effect of LLLT on hearing loss in animal models is evaluated. Hearing loss animal models were established, and the animals were irradiated by 830-nm diode laser once a day for 10 days. Power density of the laser treatment was 900 mW/cm2, and the fluence was 162 to 194 J. The tympanic membrane was evaluated after LLLT. Thresholds of auditory brainstem responses were evaluated before treatment, after gentamicin, and after 10 days of LLLT. Quantitative scanning electron microscopic (SEM) observations were done by counting remaining hair cells. Tympanic membranes were intact at the end of the experiment. No adverse tissue reaction was found. On SEM images, LLLT significantly increased the number of hair cells in middle and basal turns. Hearing was significantly improved by laser irradiation. After LLLT treatment, both the hearing threshold and hair-cell count significantly improved.

  2. Surveying Mercury Levels in Hair, Blood and Urine of under 7-Year Old Children from a Coastal City in China

    PubMed Central

    Chen, Guixia; Chen, Xiaoxin; Yan, Chonghuai; Wu, Xingdong; Zeng, Guozhang

    2014-01-01

    Aim: The average mercury load in children under 7-years old was determined in a populated but not overly industrial coastal area in China. Methods: 395 blood samples, 1072 urine samples, and 581 hair samples were collected from 1076 children, aged 0 to 6 years, from eight representative communities of Xiamen, China. Mercury levels in the samples were surveyed. Results: The 95% upper limits of mercury in blood, urine, and hair for the children were 2.30, 1.50 and 2100.00 μg/kg, respectively. Levels tended to increase with age. Correlation analyses showed that mercury levels in blood and urine correlated with those in hair (n = 132), r = 0.49, p < 0.0001 and r = 0.20, p = 0.0008; however, blood mercury levels did not correlate with urine levels (n = 284), r = 0.07, p = 0.35. Conclusions: Surveying the average mercury load in children 0 to 6 years, and the 95% upper limit value of mercury in their blood, urine, and hair should help guide risk assessment and health management for children. PMID:25419876

  3. Determination of a site-specific reference dose for methylmercury for fish-eating populations.

    PubMed

    Shipp, A M; Gentry, P R; Lawrence, G; Van Landingham, C; Covington, T; Clewell, H J; Gribben, K; Crump, K

    2000-11-01

    methylmercury, the exposures of concern for the Point Comfort site are from the chronic consumption of relatively low concentrations of methylmercury in fish. Since the publication of the USEPA RfD, several analyses of chronic exposure to methylmercury in fish-eating populations have been reported. The purpose of the analysis reported here was to evaluate the possibility of deriving an RfD for methylmercury, specifically for the case of fish ingestion, on the basis of these new studies. In order to better support the risk-management decisions associated with developing a remediation approach for the site in question, the analysis was designed to provide information on the distribution of acceptable ingestion rates across a population, which could reasonably be expected to be consistent with the results of the epidemiological studies of other fish-eating populations. Based on a review of the available literature on the effects of methylmercury, a study conducted with a population in the Seychelles Islands was selected as the critical study for this analysis. The exposures to methylmercury in this population result from chronic, multigenerational ingestion of contaminated fish. This prospective study was carefully conducted and analyzed, included a large cohort of mother-infant pairs, and was relatively free of confounding factors. The results of this study are essentially negative, and a no-observed-adverse-effect level (NOAEL) derived from the estimated exposures has recently been used by the Agency for Toxic Substances and Disease Registry (ATSDR) as the basis for a chronic oral minimal risk level (MRL) for methylmercury. In spite of the fact that no statistically significant effects were observed in this study, the data as reported are suitable for dose-response analysis using the BMD method. Evaluation of the BMD method used in this analysis, as well as in the current USEPA RfD, has demonstrated that the resulting 95% lower bound on the 10% benchmark dose (BMDL) represents a

  4. Your Hair

    MedlinePlus

    ... A Real Lifesaver Kids Talk About: Coaches Your Hair KidsHealth > For Kids > Your Hair Print A A ... eyes from sweat dripping down from your forehead. Hair Comes From Where? Whether hair is growing out ...

  5. Oily hair

    MedlinePlus

    Hair - oily ... are some tips for preventing and treating oily hair: Shampoo your hair every day. Leaving the shampoo on your head ... minutes before rinsing may help. Avoid brushing your hair too often or too vigorously, since the brushing ...

  6. Hair Loss

    MedlinePlus

    ... thyroid disease , can interfere with hair production and cause hair loss. People with lupus can also lose hair. The hormone imbalance that happens in polycystic ovary syndrome can cause hair loss in teen girls as well as ...

  7. Determination of endogenous levels of GHB in human hair. Are there possibilities for the identification of GHB administration through hair analysis in cases of drug-facilitated sexual assault?

    PubMed

    Goullé, Jean Pierre; Chèze, Marjorie; Pépin, Gilbert

    2003-01-01

    We have developed a GC-MS-MS assay for GHB in human hair. Five milligrams of washed hair were hydrolyzed by 1M or 0.01M NaOH before a liquid-liquid extraction with ethyl acetate under acidic conditions. GHB-d(6) was used as the internal standard. TMS derivatives were formed before injection. TBDMS derivatives were used in cases of strong chromatographic interferences or in a confirmatory procedure. Analysis of basal levels of GHB in 61 drug-free donors gave the following results: the mean measured concentration for blond hair was 0.60 ng/mg (n = 12), SD = 0.19 ng/mg, and extreme figures were in the range 0.35-0.95 ng/mg. For brown hair, the mean measured concentration was 0.90 ng/mg (n = 30), SD = 0.42 ng/mg, and extreme figures 0.41-1.86 ng/mg. For black hair, the mean measured concentration was 0.90 ng/mg (n = 19), SD = 0.37 ng/mg, and extreme figures 0.32-1.54 ng/mg, showing no significant differences depending on hair color. Analysis of basal levels of GHB of 12 or more specimens in segmented hair showed a mean concentration of 1.22 ng/mg (0.31-8.4 ng/mg) and a relative standard deviation for each individual ranging from 6.75% to 37.98%. GHB was administered to a healthy 53-year-old white male (light brown hair) at oral dosages of 30, 45, and 60 mg/kg. Beard hair was collected just before administration and 24 h after (and each day for one week for the last dose), and a 7.5-cm scalp hair lock was collected 7 days after the last dose. A rise in GHB concentration was observed in beard hair for the 45 and 60 mg/kg dosages with a maximum at 24 h, whereas no change was observed for the 30 mg/kg dosage. Scalp hair was segmented into 3-mm long segments. The three proximal last segments showed significantly (0.0005 < p < 0.005) different concentrations of GHB (1.22, 1.27, and 1.66 ng/mg, respectively) when compared with the basal physiological level of GHB in this same person (mean = 0.62 ng/mg, SD = 0.15 ng/mg). A case of daily GHB abuse during bodybuilding allowed us

  8. Buprenorphine and nor-buprenorphine levels in head hair samples from former heroin users under Suboxone® treatment.

    PubMed

    Belivanis, Stamatis; Tzatzarakis, Manolis N; Vakonaki, Elena; Kovatsi, Leda; Mantsi, Mary; Alegakis, Athanasios; Kavvalakis, Matthaios P; Vynias, Dionisios; Tsatsakis, Aristidis M

    2014-06-01

    In the current study, buprenorphine (BUP) and its major metabolite, nor-buprenorphine (NBUP), were determined in hair samples from former heroin users following Suboxone® treatment. Hair samples from 36 subjects were analyzed. The drugs of interest were isolated from hair by solid-liquid extraction with methanol and were determined by liquid chromatography-mass spectrometry, using an electrospray ionization interface. The analytical parameters of the method (such as linearity, limits of quantification, recovery, accuracy, and precision) were determined. The inter-quartile range of BUP levels was from 11.4 to 37.4 pg/mg (mean value 56.6 pg/mg) for the proximal hair segment, from 5.8 to 43.3 pg/mg for the middle hair segment (mean value 25.3 pg/mg), while a range from 4.3 to 33.9 pg/mg (mean value 105.2 pg/mg) for the distant to the root hair segment was determined. For NBUP the corresponding inter-quartile range was from 27.0 to 147.6 for the proximal segment (mean value 95.4 pg/mg), from 21.5 to 164.7 pg/mg for the middle segment (mean value 102.0 pg/mg) and from 20.4 to 103.6 pg/mg for the distant segment (mean value 156.8 pg/mg). The mean BUP/NBUP concentration ratio was 0.5. The daily dose of Suboxone® correlated significantly with BUP and NBUP levels in hair (p = 0.001 and p = 0.023) as well as with the BUP/NBUP ratio (p = 0.010). No significant correlation was found between the levels of BUP and NBUP and the duration of Suboxone® administration. The developed and validated method was successfully used for the determination of BUP and NBUP in hair samples collected from former heroin users under Suboxone® treatment.

  9. Effect of low level laser therapy on hair cell regeneration following gentamicin induced ototoxicity in postnatal organotypic culture of rat cochlea

    NASA Astrophysics Data System (ADS)

    Rhee, Chung-Ku; Kim, Young Hoon; Kim, Se Hyung; He, Peijie; Ahn, Jin Chul

    2010-02-01

    Aim: To investigate effects of low level laser therapy (LLLT) on hair cell regeneration following gentamicin ototoxicity in organotypic culture of rat cochlea. Methods: Organotypic cultures of cochlea in culture medium were allowed to grow for 17 days (C group). The organotypic cultures were irradiated daily with 808 nm LD laser, at 28.8 J/ cm2(L group). The organotypic culture were exposed to 1 mM of gentamicin for 48 hr and allowed to recover (G group) or allowed to recover in the culture medium with daily LLLT at 28.8 J/ cm2 (GL group) for 17 days. The cochleae were stained with FM1-43. The number of hair cells was counted in each group serially for 17 days. Results: While the C group kept on losing hair cells in vitro culture, the hair cells remained rather stationary in the L group. The number of hair cells revealed significantly larger number of hair cells in the L group compared to the C group (p=0.05). And the group × time interaction was also significant (p=0.04). That is, the number of hair cells in the C group showed decreasing tendency which was significantly different from the L group. In G group, the initial number of hair cells decreased to 37.2% of that of the gentamicin non-exposed groups. While the G group kept on losing hair cells, the number of hair cells increased in the GL group. The number of hair cells revealed significantly larger in the GL group (p=0.01) compared to G group. And the group × time interaction was also significant (p=0.01). Also, the number of hair cells in the GL group showed increasing tendency which was significantly different from the G group. Conclusion: These results suggest that LLLT promotes hair cell regeneration following gentamicin damage in cochlear explants.

  10. Decreased glutathione and elevated hair mercury levels are associated with nutritional deficiency-based autism in Oman.

    PubMed

    Hodgson, Nathaniel W; Waly, Mostafa I; Al-Farsi, Yahya M; Al-Sharbati, Marwan M; Al-Farsi, Omar; Ali, Amanat; Ouhtit, Allal; Zang, Tianzhu; Zhou, Zhaohui Sunny; Deth, Richard C

    2014-06-01

    Genetic, nutrition, and environmental factors have each been implicated as sources of risk for autism. Oxidative stress, including low plasma levels of the antioxidant glutathione, has been reported by numerous autism studies, which can disrupt methylation-dependent epigenetic regulation of gene expression with neurodevelopmental consequences. We investigated the status of redox and methylation metabolites, as well as the level of protein homocysteinylation and hair mercury levels, in autistic and neurotypical control Omani children, who were previously shown to exhibit significant nutritional deficiencies in serum folate and vitamin B₁₂. The serum level of glutathione in autistic subjects was significantly below control levels, while levels of homocysteine and S-adenosylhomocysteine were elevated, indicative of oxidative stress and decreased methionine synthase activity. Autistic males had lower glutathione and higher homocysteine levels than females, while homocysteinylation of serum proteins was increased in autistic males but not females. Mercury levels were markedly elevated in the hair of autistic subjects vs. control subjects, consistent with the importance of glutathione for its elimination. Thus, autism in Oman is associated with decreased antioxidant resources and decreased methylation capacity, in conjunction with elevated hair levels of mercury.

  11. Correlation between tryptophan and hair pigmentation in human hair.

    PubMed

    Biasiolo, M; Bertazzo, A; Costa, C V; Allegri, G

    1999-01-01

    The concentration of tryptophan in human hair of various colours is determined in order to study their correlation with hair pigmentation. The mean levels of this amino acid in hair samples are higher in men than in women. Therefore, sex influences the content of tryptophan in human hair. In addition, age influences the distribution, the highest levels are observed in the 1-5 year age-group and in ageing subjects in the groups up to 61-80 years in both sexes. The hair samples subdivided, according the colour, into blond, dark blond, red, light brown, brown, black, grey, and white demonstrate that in both sexes the concentrations of tryptophan are higher in brown and black hair than in blond hair. However, the tryptophan levels are highest in grey and white hair, showing that tryptophan accumulates among hair fibres with age. Therefore, there is a correlation between tryptophan content and hair pigmentation.

  12. Human hair lead copper levels in three occupationally unexposed population groups in Calcutta

    SciTech Connect

    Sen, J.; Chaudhuri, A.B.D.

    1996-10-01

    The element lead (Pb) has been very widely studied in man due to its widespread occurrence and toxic effects. There is no known nutritional value of Pb and it is stored in the bone by replacing calcium. In the cellular level, Pb alters cell membrane structure and membrane on function. It is a potent inhibitor of the Na{sup +} K{sup +} ATPase. Pb also interferes with the activity of the enzymes delta-aminoevulinic acid synthetase, delta-aminolevulinic dehydrase and intra-mitochondrial ferrochelatase. In the pre-natal level, Pb-exposure may lead to an increased risk of prematurity and reduction of gestational age in humans. Pb-exposure causes adverse neuro-psychological effects among young children and numerous endrocrinal disturbances among adults. It has shown that Human Scalp Hair (HSH) Pb concentration can be used very successfully to document population exposure to this toxic element. Copper is known to be biologically essential, but Cu poisoning is rare in humans. This study attempts to document exposure and to determine `base-line` values for HSH Pb and CU among three occupationally unexposed population groups in Calcutta. 15 refs., 1 tab.

  13. Determination of fumonisin B1 levels in body fluids and hair from piglets fed fumonisin B1-contaminated diets.

    PubMed

    Souto, Pollyana C M C; Jager, Alessandra V; Tonin, Fernando G; Petta, Tânia; Di Gregório, Mayra C; Cossalter, Anne-Marie; Pinton, Philippe; Oswald, Isabelle P; Rottinghaus, George E; Oliveira, Carlos A F

    2017-10-01

    The levels of fumonisin B1 (FB1) residues in plasma, urine, feces and hair from 24 piglets fed FB1-contaminated diets containing 3.1, 6.1 or 9.0 μg FB1.g(-1) for 28 days were determined using liquid chromatography coupled to mass spectrometry (LC-MS/MS). The levels of FB1 in plasma, urine, feces and pooled hair (n = 3) samples varied from 0.15 to 1.08 μg.L(-1), 16.09-75.01 μg.L(-1), 1.87-13.89 μg.g(-1) and 2.08-8.09 ng.g(-1), respectively. Significant correlations (r = 0.808-0.885; P < 0.001; N = 18) were found between FB1 intake and plasma FB1 on days 7, 14, 21 and 28. However, urinary FB1 correlated with FB1 intake only on days 7 and 14 (r = 0.561-572; P = 0.02; N = 18). A significant correlation (r = 0.509; P = 0.02; N = 24) was also found for the first time between FB1 in hair samples and FB1 intake. Plasma and urinary FB1 are good biomarkers of early exposure of pigs to low dietary FB1 levels, although plasma is recommended to assess prolonged exposure (>14 days). The possibility to evaluate hair as a biomarker of fumonisin exposure was established, although further studies are needed to provide physiologically based toxicokinetics of residual FB1 in the pig hair. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Interpretation of group-level factors from a large population dataset in the determination of ethyl glucuronide in hair.

    PubMed

    Salomone, Alberto; Pirro, Valentina; Lombardo, Tonia; Di Corcia, Daniele; Pellegrino, Sergio; Vincenti, Marco

    2015-05-01

    Ethyl glucuronide in hair (HEtG) is the most accredited marker to prove chronic alcohol abuse. In this study, we evaluate the comprehensive results of HEtG determination obtained during four years of activity (2009-2013) in our laboratory (Northwestern Italy) - across a large cohort of subjects (over 20 000 subjects mostly undergoing medical examination for driving re-licensing) - to provide a general perspective on HEtG analysis and dependence on group-level factors (e.g. age, gender, site and period of hair collection) that could bias the analytical results. HEtG was measured by liquid chromatography-tandem mass spectrometry. About 12% of the subjects presented HEtG concentrations over 30 pg/mg. Upon non-parametric hypothesis tests, distributions of HEtG in independent populations categorized by age proved statistically different, while no differences were found by considering gender, BMI, and site of sampling (head vs. chest hair). A 'seasonality' factor was evaluated by comparing periods of collection approximately representing the hair growth in winter, spring, summer and autumn, and a seasonal trend was observed showing the highest HEtG levels in winter (16.7%) and minimum levels in summer (8.3%). The experimental HEtG distributions confirm that chest hair sampling can be trusted as an alternative to scalp. Furthermore, among biological and external factors, age and season of sampling may significantly influence the measured HEtG concentration, and this potential source of bias should be taken into account when the results are interpreted.

  15. [Total mercury in hair samples of inhabitants of Tapajós River, Pará State, Brazil].

    PubMed

    Pinheiro, M C; Guimarães, G A; Nakanishi, J; Oikawa, T; Vieira, J L; Quaresma, M; Cardoso, B; Amoras, W

    2000-01-01

    This study evaluates human exposure to methylmercury in fishermen and their families in four villages on the Tapajós river: Rainha, Barreiras, São Luís do Tapajós and Paraná-Mirim. Hair analyses were performed with atomic absorption spectophotometry. Total hair mercury levels varied between 2.9mg/g and 71.5mg/g. Paraná-Mirim showed the lowest level. The highest level was found in São Luís do Tapajós and Barreiras. The hair mercury was six to seven times higher than the established safe limit of 10mg/g. No statistically significant difference was found between the mean level of total mercury taken from the inhabitants living downstream and upstream in Itaituba village (p > 0.05). These results confirm that human exposure to methylmercury is occurring on the Tapajós river and suggest that continued fish ingestion in that region is a potential risk factor for the appearance of symptoms and signs of Minamata disease. An immediate epidemiological survey program is recommended.

  16. Country-specific estimates of the incidence of intellectual disability associated with prenatal exposure to methylmercury.

    PubMed

    Bellinger, David C; O'Leary, Keri; Rainis, Holly; Gibb, Herman J

    2016-05-01

    This paper describes country-specific estimates of the incidence of intellectual disability in children associated with prenatal exposure to methylmercury. A systematic review was undertaken to identify country-specific data on hair mercury concentrations in women of reproductive age. A variety of approaches were used to estimate biomarker concentrations for countries lacking such data. A dose-effect relationship derived on the basis of the data from three large prospective studies relating prenatal methylmercury exposure to IQ in children was used to estimate the country-specific incidences of mild, moderate, severe, and profound intellectual disability in children as a result of prenatal methylmercury exposure. The incidence of methylmercury-associated mild intellectual disability (IQ scores 50-70) varied nearly 40-fold across countries, with the greatest incidences generally in countries that are islands or that are coastal. Countries with high birth rates and greater consumption of foods that contribute most to methylmercury intake in humans (seafood, rice) can be expected to make the largest contributions to the worldwide burden of disease associated with methylmercury. The assumptions and limitations of the estimates are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Accelerated methylmercury elimination in gamma-glutamyl transpeptidase-deficient mice.

    PubMed Central

    Ballatori, N.; Wang, W.; Lieberman, M. W.

    1998-01-01

    The disposition and toxicity of methylmercury, a ubiquitous environmental pollutant, is modulated by binding to the endogenous tripeptide glutathione (GSH) and metabolism of the resulting methylmercury-glutathione complex by the ectoproteins gamma-glutamyl transpeptidase (GGT) and dipeptidase. To evaluate the role of GGT in the whole-body disposition of methylmercury, we compared the elimination of [203Hg]methylmercury in GGT-deficient mice with that in wild-type mice and mice heterozygous for this deficiency. The effects of N-acetylcysteine (NAC), a drug used to maintain the cysteine and GSH levels of GGT-deficient mice, were also examined. Female mice were treated with either 0.5 or 25 micromol of CH3 203HgCl/kg body weight, in the presence and absence of 10 mg/ml NAC in the drinking water. There were no differences in methylmercury excretion between the wild-type and heterozygous mice; however, the GGT-deficient mice excreted methylmercury more rapidly at both dose levels. Wild-type and heterozygous mice excreted from 11 to 24% of the dose in the first 48 hours, whereas the GGT-deficient mice excreted 55 to 66% of the dose, with most of the methylmercury being excreted in urine. Urinary methylmercury excretion was further accelerated in mice that received NAC. In contrast to methylmercury, the whole-body elimination of inorganic mercury was not affected by GGT deficiency, although the tissue distribution of inorganic mercury was markedly different in GGT-deficient male mice, with only 13% of the 203Hg body burden in the kidneys of GGT-deficient mice versus approximately 50% in kidneys of wild-type male mice. These findings provide direct evidence for a major role of GGT in regulating the tissue distribution and elimination of methylmercury and inorganic mercury and provide additional support for the use of NAC as an antidote in methylmercury poisoning. PMID:9546365

  18. Fish consumption patterns and mercury exposure levels among women of childbearing age in Duval County, Florida.

    PubMed

    Traynor, Sharleen; Kearney, Greg; Olson, David; Hilliard, Aaron; Palcic, Jason; Pawlowicz, Marek

    2013-01-01

    Consumption of fish containing methylmercury can pose serious health concerns including neurotoxic effects in adults and toxicity to the fetuses of mothers exposed during pregnancy. In the study described in this article, the authors examined fish consumption patterns and measured hair mercury levels of women of childbearing age in a coastal county in Florida. Women from the community participated in a risk factor assessment survey (N = 703). Hair samples (n = 698) were collected and analyzed for mercury. The authors identified 74.8% below detection limit; 25.2% had detectable limits of mercury, while 7% exceeded 1 pg/g. Hair mercury levels increased with fish consumption and age. Race, income, and education levels were also associated with increased hair mercury levels. Women of Asian/Pacific Islander origin had the highest levels. Although reported fish consumption exceeded the recommendations for women of childbearing age, the study population had lower mercury levels than other comparative studies in Florida and at national levels.

  19. Evaluation of wavelength-dependent hair growth effects on low-level laser therapy: an experimental animal study.

    PubMed

    Kim, Tae-Hoon; Kim, Nam-Jeong; Youn, Jong-In

    2015-08-01

    In this study, we aimed to investigate the wavelength-dependent effects of hair growth on the shaven backs of Sprague-Dawley rats using laser diodes with wavelengths of 632, 670, 785, and 830 nm. Each wavelength was selected by choosing four peak wavelengths from an action spectrum in the range 580 to 860 nm. The laser treatment was performed on alternating days over a 2-week period. The energy density was set to 1.27 J/cm(2) for the first four treatments and 1.91 J/cm(2) for the last four treatments. At the end of the experiment, both photographic and histological examinations were performed to evaluate the effect of laser wavelength on hair growth. Overall, the results indicated that low-level laser therapy (LLLT) with a 830-nm wavelength resulted in greater stimulation of hair growth than the other wavelengths examined and 785 nm also showed a significant effect on hair growth.

  20. Assessment of saliva, hair and toenails as biomarkers of low level exposure to manganese from drinking water in children.

    PubMed

    Ntihabose, Ruth; Surette, Céline; Foucher, Delphine; Clarisse, Olivier; Bouchard, Maryse F

    2017-09-01

    We evaluated hair, toenails, and saliva (whole and supernatant) as biomarkers of exposure to manganese (Mn) in 274 school age children (6-13 years) consuming well water in southeastern New Brunswick, Canada. Mn concentrations in tap water ranged from <0.03 to 1046μgL(-1) (geometric mean 5.96μgL(-1)). The geometric mean of Mn intake resulting from the consumption of water was 0.25 (0-34.95) μg kg(-1)day(-1). Both Mn concentration in water and Mn intake were significantly correlated with Mn in hair (r=0.60 and r=0.53, respectively), Mn in toenail (r=0.29 and r=0.37 respectively) and to a lesser extent with Mn in saliva supernatant (r=0.14 and r=0.18, respectively). Mn in whole saliva did not correlate with Mn in water or Mn intake. Both Mn in hair and Mn in toenail allowed to discriminate the most exposed group from the least exposed group, based on Mn in water and Mn intake from water. In this group of children with low level Mn exposure, Mn concentrations in hair, and toenails reflected reasonably well Mn exposure from drinking water, whereas Mn content in saliva correlated less strongly. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Lack of relationship between hair lead levels and some usual markers (blood lead levels, ZPP, urinary ALA-D) in occupationally exposed workers.

    PubMed

    Tracqui, A; Bosque, M A; Costa, V; Kintz, P; Siegel, F; Mangin, P

    1994-01-01

    Blood and hair samples collected from 54 male workers occupationally exposed to lead were assayed for this metal by graphite furnace atomic absorption spectrophotometry. Blood ZPP and urinary ALA-D were also determined for most subjects tested. Blood and hair lead concentrations (PbB and PbH) ranged from 100 to 770 ng/ml (10 to 77 micrograms/100 ml) (mean +/- SD: 384.6 +/- 143.4 ng/ml (38.46 +/- 14.34 micrograms/100 ml)), and from 3 to 243 ng/mg (mean +/- SD: 102.4 +/- 72.6 ng/mg), respectively. No correlation was observed between the PbH and PbB values, nor between PbH and ZPP or ALA-D values. Neither hair coloration nor subjects' age were related to PbH levels. Results are discussed in the light of the existing literature.

  2. Fish consumption, methylmercury and child neurodevelopment.

    PubMed

    Oken, Emily; Bellinger, David C

    2008-04-01

    To summarize recent evidence regarding associations of early life exposure to mercury from maternal fish consumption during pregnancy, thimerosal in vaccines and dental amalgam with child neurodevelopment. Recent publications have built upon previous evidence demonstrating mild detrimental neurocognitive effects from prenatal methylmercury exposure from maternal fish consumption during pregnancy. New studies examining the effects of prenatal fish consumption as well as methylmercury suggest there are benefits from prenatal fish consumption, but also that consumption of fish high in mercury should be avoided. Future studies incorporating information on both the methylmercury and the docosahexaenoic acid contained within fish will help to refine recommendations to optimize outcomes for mothers and children. Additional recent studies have supported the safety of vaccines containing thimerosal and of dental amalgam for repair of dental caries in children. Exposure to mercury may harm child development. Interventions intended to reduce exposure to low levels of mercury in early life must, however, be carefully evaluated in consideration of the potential attendant harm from resultant behavior changes, such as reduced docosahexaenoic acid exposure from lower seafood intake, reduced uptake of childhood vaccinations and suboptimal dental care.

  3. Fish consumption, methylmercury and child neurodevelopment

    PubMed Central

    Oken, Emily; Bellinger, David C.

    2008-01-01

    Purpose of review To summarize recent evidence regarding associations of early life exposure to mercury from maternal fish consumption during pregnancy, thimerosal in vaccines and dental amalgam with child neurodevelopment. Recent findings Recent publications have built upon previous evidence demonstrating mild detrimental neurocognitive effects from prenatal methylmercury exposure from maternal fish consumption during pregnancy. New studies examining the effects of prenatal fish consumption as well as methylmercury suggest there are benefits from prenatal fish consumption, but also that consumption of fish high in mercury should be avoided. Future studies incorporating information on both the methylmercury and the docosahexaenoic acid contained within fish will help to refine recommendations to optimize outcomes for mothers and children. Additional recent studies have supported the safety of vaccines containing thimerosal and of dental amalgam for repair of dental caries in children. Summary Exposure to mercury may harm child development. Interventions intended to reduce exposure to low levels of mercury in early life must, however, be carefully evaluated in consideration of the potential attendant harm from resultant behavior changes, such as reduced docosahexaenoic acid exposure from lower seafood intake, reduced uptake of childhood vaccinations and suboptimal dental care. PMID:18332715

  4. Short term synaptic plasticity regulates the level of olivocochlear inhibition to auditory hair cells

    PubMed Central

    Ballestero, Jimena; de San Martín, Javier Zorrilla; Goutman, Juan; Elgoyhen, Ana Belén; Fuchs, Paul A.; Katz, Eleonora

    2011-01-01

    In the mammalian inner ear, the gain control of auditory inputs is exerted by medial olivocochlear (MOC) neurons that innervate cochlear outer hair cells (OHCs). OHCs mechanically amplify the incoming sound waves by virtue of their electromotile properties while the MOC system reduces the gain of auditory inputs by inhibiting OHCs function. How this process is orchestrated at the synaptic level remains unknown. In the present study, MOC firing was evoked by electrical stimulation in an isolated mouse cochlear preparation, while OHCs postsynaptic responses were monitored by whole-cell recordings. These recordings confirmed that electrically evoked inhibitory postsynaptic currents (eIPSCs) are mediated solely by α9α10 nicotinic acetylcholine receptors (nAChRs) functionally coupled to calcium-activated SK2 channels. Synaptic release occurred with low probability when MOC-OHC synapses were stimulated at 1Hz. However, as the stimulation frequency was raised, the reliability of release increased due to presynaptic facilitation. In addition, the relatively slow decay of eIPSCs gave rise to temporal summation at stimulation frequencies above 10 Hz. The combined effect of facilitation and summation resulted in a frequency-dependent increase in the average amplitude of inhibitory currents in OHCs. Thus, we have demonstrated that short-term plasticity is responsible for shaping MOC inhibition and, therefore, encodes the transfer function from efferent firing frequency to the gain of the cochlear amplifier. PMID:21994392

  5. Effect of low-level laser treatment on cochlea hair-cell recovery after acute acoustic trauma

    NASA Astrophysics Data System (ADS)

    Rhee, Chung-Ku; Bahk, Chan Woong; Kim, Se Hyung; Ahn, Jin-Chul; Jung, Jae Yun; Chung, Phil-Sang; Suh, Myung-Whan

    2012-06-01

    We investigated the effect of low-level laser radiation on rescuing hair cells of the cochlea after acute acoustic trauma and hearing loss. Nine rats were exposed to noise. Starting the following day, the left ears (NL ears) of the rats were irradiated at an energy output of 100 to 165 mW/cm2 for 60 min for 12 days in a row. The right ears (N ears) were considered as the control group. Frequency-specific hearing levels were measured before the noise exposure and also after the 1st, 3rd to 5th, 8th to 10th and 12th irradiations. After the 12th treatment, hair cells were observed using a scanning electron microscope. Compared to initial hearing levels at all frequencies, thresholds increased markedly after noise exposure. After the 12th irradiation, hearing threshold was significantly lower for the NL ears compared to the N ears. When observed using an electron microscope, the number of hair cells in the middle turn of the NL ears was significantly larger than that of the N ears. Our findings suggest that low-level laser irradiation promotes recovery of hearing thresholds after acute acoustic trauma.

  6. Determination of arsenic and mercury level in scalp hair from a selected population in Penang, Malaysia using XRF technique

    NASA Astrophysics Data System (ADS)

    Aldroobi, Khalid Saleh Ali; Shukri, A.; Bauk, Sabar; Munem, Eid Mahmoud Abdel; Abuarra, Ali. M. A.

    2013-10-01

    As with many cities all over the world with active industrial developments, the city of Penang in Malaysia has also the potential of being exposed to industrial pollution. Such exposure would certainly have a detrimental impact on the environment and the people. The determination of trace elemental levels in hair which is well known as a method for environmental exposure monitoring, evaluation of heavy metal poisoning, assessment of nutrient levels and disease diagnoses. In this study, it is selected as the method to determine the possible exposure to pollutants in the form of unwanted trace elements. The natural levels of trace elements in hair are hence monitored first as reference values for the assessment of the possible human contamination levels. In this work the concentrations of As and Hg in the human scalp hair of 100 residents of Penang were determined using XRF. The results of this study are compared with the results obtained in other cities where such measurements have also been carried out.

  7. Hair cortisol levels, perceived stress and body mass index in women and children living in socioeconomically disadvantaged neighborhoods: the READI study.

    PubMed

    Olstad, Dana Lee; Ball, Kylie; Wright, Craig; Abbott, Gavin; Brown, Erin; Turner, Anne Isabella

    2016-01-01

    Disadvantaged communities provide adverse psychosocial exposures that have been linked to high levels of stress, and this may provide one explanatory pathway linking socioeconomic disadvantage to obesity. This study used hair cortisol analysis to quantify associations between stress and body mass index (BMI), and between hair cortisol and perceived psychological stress levels, in women and children living in socioeconomically disadvantaged neighborhoods. Participants were a volunteer sample of 70 women from the Resilience for Eating and Activity Despite Inequality study, including 30 maternal-child pairs. Women self-reported body weight, height and perceived psychological stress using the Perceived Stress Scale (PSS), and provided hair samples for themselves and their child. Children's body weight and height were measured. Following extraction, hair cortisol levels were measured using enzyme-linked immunosorbent assay. Multiple linear regression models examined associations between stress and BMI, and between hair cortisol and perceived stress levels in women and children. Women's hair cortisol levels were not associated with their BMI or PSS scores. Women's PSS scores were positively associated with their BMI (p = 0.015). Within maternal-child pairs, mothers and children's hair cortisol levels were strongly positively associated (p = 0.006). Maternal hair cortisol levels and PSS scores were unrelated to their child's zBMI. Children's hair cortisol levels were not associated with their zBMI or with their mother's PSS score. Findings suggest that cortisol-based and perceived psychological measures of stress may be distinct among women and children living in disadvantaged neighborhoods. Perceived psychological measures may be more important predictors of weight-related risk.

  8. Age-dependent lower or higher levels of hair mercury in autistic children than in healthy controls.

    PubMed

    Majewska, Maria Dorota; Urbanowicz, Ewa; Rok-Bujko, Paulina; Namyslowska, Irena; Mierzejewski, Paweł

    2010-01-01

    An association between autism and early life exposure to mercury is a hotly debated issue. In this study, 91 autistic Polish children, male and female, 3-4 and 7-9 years old, were compared to 75 age- and sex-matched healthy children with respect to: demographic, perinatal, clinical and developmental measures, parental age, birth order, morphometric measures, vaccination history, and hair mercury content. In demographic and perinatal measures there were no consistent differences between the autistic and control groups. Autistic children had a significantly greater prevalence of adverse reactions after vaccinations and abnormal development than controls. Between 45 and 80% of autistic children experienced developmental regress. Autistic children significantly differed from healthy peers in the concentrations of mercury in hair: younger autistics had lower levels, while older - higher levels than their respective controls. The results suggest that autistic children differ from healthy children in metabolism of mercury, which seems to change with age.

  9. Methylmercury risk assessment issues

    SciTech Connect

    Lipfert, F.W.; Saroff, L.

    1996-07-01

    This paper reviews the general background of health risks associated with mercury (Hg), primarily methylmercury (MeHg), with a view towards application to advanced technologies that could reduce any contributions from coal combustion. The need for accurate assessment of such risks is discussed, since Hg is now widely dispersed in the environment and cannot easily be eliminated. The primary pathway of MeHg intake is through eating contaminated fish. The issues of concern include identification of critical health outcomes (various neurological indices) and their confounding factors, accurate assessment of MeHg intake rates, and appropriate use of dose-response functions. Ultimately, such information will be used to evaluate alternative coal combustion systems.

  10. An exposure assessment for methylmercury from seafood for consumers in the United States.

    PubMed

    Carrington, Clark D; Bolger, Michael P

    2002-08-01

    An exposure model was developed to relate seafood consumption to levels of methylmercury (reported as mercury) in blood and hair in the U.S. population, and two subpopulations defined as children aged 2-5 and women aged 18-45. Seafood consumption was initially modeled using short-term (three-day) U.S.-consumption surveys that recorded the amount of fish eaten per meal. Since longer exposure periods include more eaters with a lower daily mean intake, the consumption distribution was adjusted by broadening the distribution to include more eaters and reducing the distribution mean to keep total population intake constant. The estimate for the total number of eaters was based on long-term purchase diaries. Levels of mercury in canned tuna, swordfish, and shark were based on FDA survey data. The distribution of mercury levels in other species was based on reported mean levels, with the frequency of consumption of each species based on market share. The shape distribution for the given mean was based on the range of variation encountered among shark, tuna, and swordfish. These distributions were integrated with a simulation that estimated average daily intake over a 360-day period, with 10,000 simulated individuals and 1,000 uncertainty iterations. The results of this simulation were then used as an input to a second simulation that modeled levels of mercury in blood and hair. The relationship between dietary intake and blood mercury in a population was modeled from data obtained from a 90-day study with controlled seafood intake. The relationship between blood and hair mercury in a population was modeled from data obtained from several sources. The biomarker simulation employed 2,000 simulated individuals and 1,000 uncertainty iterations. These results were then compared to the recent National Health and Nutrition Examination Survey (NHANES) that tabulated blood and hair mercury levels in a cross-section of the U.S. population. The output of the model and NHANES results

  11. Socioeconomic status in children is associated with hair cortisol levels as a biological measure of chronic stress.

    PubMed

    Vliegenthart, J; Noppe, G; van Rossum, E F C; Koper, J W; Raat, H; van den Akker, E L T

    2016-03-01

    Low socioeconomic status (SES) may be associated with a high risk of lifestyle-related diseases such as cardiovascular diseases. There is a strong association between parental SES, stress and indicators of child health and adult health outcome. The exact mechanisms underlying this association have not yet been fully clarified. Low SES may be associated with chronic stress, which may lead to activation of the hypothalamic-pituitary-adrenal (HPA)-axis, resulting in a higher circulating level of the stress hormone cortisol. Therefore, chronic stress may mediate the association between low SES and elevated cortisol levels and its adverse outcomes. We investigated whether SES was associated with a chronic measure of cortisol exposure in a child population. Cortisol and cortisone were measured in scalp hair in 270 children and adolescents, aged 4-18 years, enrolled through school visits. Neighborhood level SES was based on a score developed by the Netherlands Institute for Social Research using postal codes, and this includes neighborhood measures of income education and unemployment. Maternal and paternal education level were used as indicators of family SES. Neighborhood level socioeconomic status score was significantly associated with hair cortisol (β=-0.103, p=0.007, 95%CI [-0.179, -0.028]) and hair cortisone (β=-0.091, p=0.023, 95%CI [-0.167, -0.015]), adjusted for age and sex. Additionally, hair cortisol was significantly correlated with maternal education level and hair cortisone was significantly correlated with paternal education level. The results of our study suggest that the widely shown association between low family SES and adverse child health outcomes may be mediated by chronic stress, given the chronically higher levels of cortisol in children and adolescents in families with low SES. It is especially notable that the association between SES and cortisol was already found in children of young age as this can have major consequences, such as increased

  12. Correlation of lithium levels between drinking water obtained from different sources and scalp hair samples of adult male subjects.

    PubMed

    Baloch, Shahnawaz; Kazi, Tasneem Gul; Afridi, Hassan Imran; Baig, Jameel Ahmed; Talpur, Farah Naz; Arain, Muhammad Balal

    2016-10-18

    There is some evidence that natural levels of lithium (Li) in drinking water may have a protective effect on neurological health. In present study, we evaluate the Li levels in drinking water of different origin and bottled mineral water. To evaluate the association between lithium levels in drinking water with human health, the scalp hair samples of male subjects (25-45 years) consumed drinking water obtained from ground water (GW), municipal treated water (MTW) and bottled mineral water (BMW) from rural and urban areas of Sindh, Pakistan were selected. The water samples were pre-concentrated five to tenfold at 60 °C using temperature-controlled electric hot plate. While scalp hair samples were oxidized by acid in a microwave oven, prior to determined by flame atomic absorption spectrometry. The Li content in different types of drinking water, GW, MTW and BMW was found in the range of 5.12-22.6, 4.2-16.7 and 0.0-16.3 µg/L, respectively. It was observed that Li concentration in the scalp hair samples of adult males consuming ground water was found to be higher, ranged as 292-393 μg/kg, than those who are drinking municipal treated and bottle mineral water (212-268 and 145-208 μg/kg), respectively.

  13. Hair cortisone level is associated with PTSD׳s dysphoric arousal symptoms in highly traumatized Chinese females.

    PubMed

    Wang, Weiwen; Deng, Huihua; Wang, Li; Cao, Chengqi; Xu, Hang; Zhang, Jianxin

    2015-08-15

    Cortisone has been proposed as a useful additional biomarker for stress research. However, only very limited studies has investigated alterations of cortisone levels in stress-related mental disorder such as PTSD. The present study investigated the associations between PTSD symptomatology and hair cortisone levels which can reflect cumulative cortisone secretion over prolonged periods of time and is more robust to the influence of situational confounding. Participants included 201 females who experienced 2008 Wenchuan earthquake and lost their children during the disaster. PTSD symptoms were assessed with the PTSD Checklist (PCL), and depression symptoms with the Center for epidemiological studies depression scale (CES-D). Hair cortisone levels were quantified by liquid chromatography tandem mass spectrometer. The results indicated that although hair cortisone secretion could not distinguish traumatized individuals with and without PTSD, it was uniquely linked to dysphoric arousal symptoms, a key aspect of the complex PTSD phenotype A sample of females exposed to specific traumatic events was used, and PTSD was assessed using a self-reported measure. The findings provide preliminary evidence supporting the critical role of long-term cortisone changes in the development and maintenance of PTSD symptoms, and add to extant knowledge on the neuroendocrinological underpinnings of posttraumatic psychopathology. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Reconnaissance of mercury and methylmercury in the St. Croix River and selected tributaries, Minnesota and Wisconsin, July 2000 through October 2001

    USGS Publications Warehouse

    Payne, G.A.; Hansen, Donald S.

    2003-01-01

    A reconnaissance-level assessment to characterize total mercury and methylmercury concentrations during summer lowflow conditions was conducted in the St. Croix River Basin during July 2000 through October 2001. Samples were collected at 6 main stem and 16 tributary sites. Loads of total mercury and methylmercury increased in the St. Croix River main stem between Nevers Dam and Franconia. Total mercury and methylmercury concentrations were greatest during July in the Namekagon River. Methylmercury yields in the Namekagon River and Rush Creek were greater than the yield for other tributary streams. Methylmercury concentrations and yields were greater in tributaries draining wetland/forest watersheds than in tributaries draining agricultural/forest watersheds.

  15. Your Hair

    MedlinePlus

    ... person's hair may look greasy. Time for a shampoo! continue Hair Today, Gone Tomorrow! You have more ... When you wash your hair, use a gentle shampoo and warm water. Lather up using your fingertips, ...

  16. Hair Loss

    MedlinePlus

    ... Right Sport for You Healthy School Lunch Planner Hair Loss KidsHealth > For Teens > Hair Loss Print A A ... the underlying problem, if necessary. continue What Causes Hair Loss? Here are some of the things that can ...

  17. Low-level laser treatment stimulates hair growth via upregulating Wnt10b and β-catenin expression in C3H/HeJ mice.

    PubMed

    Zhang, Tiran; Liu, Liqiang; Fan, Jincai; Tian, Jia; Gan, Cheng; Yang, Zengjie; Jiao, Hu; Han, Bing; Liu, Zheng

    2017-07-01

    This study was conducted in order to evaluate the role of low-level laser treatment (LLLT) in hair growth in C3H/HeJ mice. Healthy C57BL/6 mice were randomly divided into two groups: with and without low-level laser treatment. The skin color of each mouse was observed each day. Skin samples were collected for H&E, immunofluorescence, PCR, and western blot analysis, to observe the morphology of hair follicles and detect the expression levels of Wnt10b and β-catenin. Observation of skin color demonstrated that black pigmentation started significantly earlier in the laser group than in the control group. Hair follicle number in both groups showed no difference; however, the hair follicle length presented a significant difference. Wnt10b protein was detected on the second day in hair matrix cells in the LLLT group but not in the control group. PCR and western blot results both illustrated that expression of Wnt10b and β-catenin was significantly higher in the LLLT group than in the control group. Our study illustrated that low-level laser treatment can promote hair regrowth by inducing anagen phase of hair follicles via initiating the Wnt10b/β-catenin pathway.

  18. Retrospective study on temporal and regional variations of methylmercury concentrations in preserved umbilical cords collected from inhabitants of the Minamata area, Japan.

    PubMed

    Sakamoto, Mineshi; Murata, Katsuyuki; Tsuruta, Kazuhito; Miyamoto, Kenichiro; Akagi, Hirokatsu

    2010-09-01

    The present study was conducted to investigate the historical time-course changes and regional distribution of methylmercury concentrations in preserved umbilical cords collected from Minamata-area inhabitants born between 1947 and 1989. The data from Miyazaki, Tottori, Akita, Tsushima (Nagasaki), Fukuoka and Tokyo were used as controls. A total of 325 data were analyzed to estimate the temporal and spatial distribution of methylmercury among inhabitants born in the Minamata area. Elevated methylmercury concentrations (>or=1 microg/g) were mainly observed in inhabitants born between 1947 and 1968. That peak coincided with the peak of acetaldehyde production in Minamata. The methylmercury concentrations started to decrease in keeping with the decline of acetaldehyde production, which ceased in 1968, and thereafter the methylmercury levels gradually decreased to the control levels. Elevated methylmercury concentrations were first observed in the districts of Minamata, followed by Izumi, Tsunagi and Ashikita, indicating the time-course-dependent regional distributions of methylmercury pollution.

  19. Long-term exposure to methylmercury and its effects on hypertension in Minamata.

    PubMed

    Yorifuji, Takashi; Tsuda, Toshihide; Kashima, Saori; Takao, Soshi; Harada, Masazumi

    2010-01-01

    Recent studies suggest potential adverse effects of methylmercury exposure on cardiovascular disease, although the evidence of association with hypertension is still inconsistent. Therefore, we evaluated the effects of methylmercury exposure on hypertension in Minamata. We used data derived from the 1971 population-based survey in Minamata and neighboring communities. We also utilized data on hair mercury content of the participants (derived from a 1960 investigation). We adopted two exposure indices (residential area and hair mercury content) and two hypertension outcomes (past history of hypertension and hypertension defined by measurements in the examination). Then, we estimated the adjusted prevalence odds ratio (POR) and its confidence interval (CI) of both hypertension outcomes in relation to residential area and hair mercury content. In the Minamata area (high exposure area), 87% (833) of the eligible population (aged > or =10 years) participated in the 1971 investigations. In the Goshonoura area (middle exposure area) and the Ariake area (low exposure area), 93% (1450) and 77% (755), respectively, of the eligible population participated. Compared with subjects in the Ariake area, the subjects in the Minamata area manifested hypertension more frequently, and PORs observed for two hypertension outcomes were 1.6 (95% CI: 1.2-2.1) and 1.4 (95% CI: 1.1-1.9), respectively. Furthermore, dose-response trends with hair mercury content were observed for both hypertension outcomes. The present finding supports the causal relationship between methylmercury exposure and hypertension.

  20. Methylmercury Concentration in Fish and Risk-Benefit Assessment of Fish Intake among Pregnant versus Infertile Women in Taiwan.

    PubMed

    Hsi, Hsing-Cheng; Hsu, You-Wen; Chang, Tien-Chin; Chien, Ling-Chu

    2016-01-01

    This study examined methylmercury (MeHg) concentrations in fish, the daily MeHg exposure dose, and the risk-benefit of MeHg, ω-3 polyunsaturated fatty acid (ω-3 PUFA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) related to fish intake among pregnant and infertile women in Taiwan. The measured MeHg concentrations in fish did not exceed the Codex guideline level of 1 mg/kg. Swordfish (0.28 ± 0.23 mg/kg) and tuna (0.14 ± 0.13 mg/kg) had the highest MeHg concentrations. The MeHg concentration in the hair of infertile women (1.82 ± 0.14 mg/kg) was significantly greater than that of pregnant women (1.24 ± 0.18 mg/kg). In addition, 80% of infertile women and 68% of pregnant women had MeHg concentrations in hair that exceeded the USEPA reference dose (1 mg/kg). The MeHg concentrations in hair were significantly and positively correlated with the estimated daily MeHg exposure dose. Based on the risk-benefit evaluation results, this paper recommends consumption of fish species with a low MeHg concentration and high concentrations of DHA + EPA and ω-3 PUFA (e.g., salmon, mackerel, and greater amberjack).

  1. Methylmercury Concentration in Fish and Risk-Benefit Assessment of Fish Intake among Pregnant versus Infertile Women in Taiwan

    PubMed Central

    Hsi, Hsing-Cheng; Hsu, You-Wen; Chang, Tien-Chin; Chien, Ling-Chu

    2016-01-01

    This study examined methylmercury (MeHg) concentrations in fish, the daily MeHg exposure dose, and the risk–benefit of MeHg, ω-3 polyunsaturated fatty acid (ω-3 PUFA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) related to fish intake among pregnant and infertile women in Taiwan. The measured MeHg concentrations in fish did not exceed the Codex guideline level of 1 mg/kg. Swordfish (0.28 ± 0.23 mg/kg) and tuna (0.14 ± 0.13 mg/kg) had the highest MeHg concentrations. The MeHg concentration in the hair of infertile women (1.82 ± 0.14 mg/kg) was significantly greater than that of pregnant women (1.24 ± 0.18 mg/kg). In addition, 80% of infertile women and 68% of pregnant women had MeHg concentrations in hair that exceeded the USEPA reference dose (1 mg/kg). The MeHg concentrations in hair were significantly and positively correlated with the estimated daily MeHg exposure dose. Based on the risk–benefit evaluation results, this paper recommends consumption of fish species with a low MeHg concentration and high concentrations of DHA + EPA and ω-3 PUFA (e.g., salmon, mackerel, and greater amberjack). PMID:27187161

  2. Excessive or unwanted hair in women

    MedlinePlus

    Hypertrichosis; Hirsutism; Hair - excessive (women); Excessive hair in women; Hair - women - excessive or unwanted ... Women normally produce low levels of male hormones (androgens). If your body makes too much of this ...

  3. Neurological and neurocognitive functions from intrauterine methylmercury exposure.

    PubMed

    Yorifuji, Takashi; Kado, Yoko; Diez, Midory Higa; Kishikawa, Toshihiro; Sanada, Satoshi

    2016-05-03

    In the 1950s, large-scale food poisoning caused by methylmercury was identified in Minamata, Japan. Although severe intrauterine exposure cases (ie, congenital Minamata disease patients) are well known, possible impacts of methylmercury exposure in utero among residents, which is likely at lower levels than in congenital Minamata disease patients, are rarely explored. In 2014, the authors examined neurological and neurocognitive functions among 18 exposed participants in Minamata, focusing on fine motor, visuospatial construction, and executive functions. More than half of the participants had some fine motor and coordination difficulties. In addition, several participants had lower performance for neurocognitive function tests (the Rey-Osterrieth Complex Figure test and Keio version of the Wisconsin card sorting test). These deficits imply diffuse brain damage. This study suggests possible neurological and neurocognitive impacts of prenatal exposure to methylmercury among exposed residents of Minamata.

  4. Accumulation of brominated flame retardants and polychlorinated biphenyls in human breast milk and scalp hair from the Philippines: levels, distribution and profiles.

    PubMed

    Malarvannan, Govindan; Isobe, Tomohiko; Covaci, Adrian; Prudente, Maricar; Tanabe, Shinsuke

    2013-01-01

    Paired human breast milk and scalp hair samples (n=30) were obtained in 2008 from primipara and multipara mothers living in two locations in the Philippines viz., Payatas, a waste dumpsite, and Malate, a non-dumpsite. Samples were analyzed for three groups of organohalogenated compounds, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs). PCBs were the predominantly identified compounds (median: 70 ng/g lipid wt.) in all the breast milk samples. In the human milk, CB-153 was the most dominant PCB congener (17-44% contribution to the sum PCB), closely followed by CB-138 (12-35%), CB-118 (4-12%), CB-180 (2-13%), CB-187 (3-13%), and CB-170 (1.5-10%). Levels of PBDEs (median: 3.0 ng/g lipid wt.) in human milk samples from the Philippines were similar to other Asian or European countries. BDE-47, -99, -100 and -153 were the major PBDE congeners. For HBCDs, the α-isomer was predominant followed by the γ-HBCD isomer in the both locations. PBDE levels in human milk were significantly higher in the dumpsite (3.9 ng/g lipid wt.) than in the non-dump site (2.2 ng/g lipid wt.). PBDE concentrations (including BDE-209) were significantly higher (median: 70 ng/g hair) than those of PCBs (median: 30 ng/g hair) and HBCDs (median: 1.0 ng/g hair) in all the scalp hair samples. To our knowledge, this is the first report on HBCDs in human scalp hair. PBDE congeners in scalp hair were dominated by BDE-209 and BDE-47. On a congener basis, the levels of PBDEs found in scalp hair were higher than those in Spain (children and adults) and China (general people). PCB levels found in scalp hair were higher than those in Greece, Romania and Belgium, but lower than those in China. In this study, there were no significant differences in the concentration of PCBs and HBCDs in human milk; and PCBs, HBCDs and PBDEs in human scalp hair from the two different locations. No significant correlations were observed between PCBs, PBDEs and

  5. A Critical Assessment of the Evidence for Low-Level Laser Therapy in the Treatment of Hair Loss.

    PubMed

    Gupta, Aditya K; Foley, Kelly A

    2017-02-01

    Low-level laser therapy (LLLT) is currently in use to stimulate hair growth and is quickly gaining in popularity due to the ease of use and absence of side effects. In 2015 alone, the number of LLLT devices with the Food and Drug Administration clearance has doubled. To consolidate evidence and establish which data are still required for the widespread acceptance of LLLT for hair loss therapy. A thorough search of the PubMed database was conducted to obtain studies investigating LLLT for androgenetic alopecia in men and women. Nine trials were identified for comb and helmet/cap devices, five of which were randomized controlled trials. Data comparison across LLLT trials and with traditional hair loss therapy (minoxidil, finasteride) was not straight forward because there was a lack of visual evidence, sample sizes were low, and there were large variations in study duration and efficacy measurements. There are a number of unanswered questions about the optimum treatment regimen, including maintenance treatment and the long-term consequences of LLLT use. Moving forward, protocols should be standardized across trials. Moreover, it is recommended that future trials include visual evidence and trial duration be expanded to 12 months.

  6. Parasites, stress and reindeer: infection with abomasal nematodes is not associated with elevated glucocorticoid levels in hair or faeces

    PubMed Central

    Carlsson, A. M.; Mastromonaco, G.; Vandervalk, E.; Kutz, S.

    2016-01-01

    Stress hormones (glucocorticoids), incorporated into hair/fur and faeces, have been proposed as biomarkers of overall health in wildlife. Although such biomarkers may be helpful for wildlife conservation and management, their use has rarely been validated. There is a paucity of studies examining the variation of stress hormones in mammals and how they relate to other health measures, such as parasitism. Parasites are ubiquitous in wildlife and can influence the fitness of individual animals and populations. Through a longitudinal experiment using captive reindeer (Rangifer tarandus tarandus), we tested whether animals infected with Ostertagia gruehneri, a gastrointestinal nematode with negative impacts on fitness of the host, had higher stress levels compared with those that had been treated to remove infection. Faecal samples were collected weekly for 12 weeks (June–September) and hair was collected at the start and end of the study; glucocorticoids were quantified using enzyme immunoassays. Contrary to what was expected, infected reindeer had similar levels of cortisol in hair and slightly lower glucocorticoid metabolites in faeces compared with uninfected reindeer. Faecal corticosterone levels were higher than faecal cortisol levels, and only corticosterone increased significantly after a handling event. These results suggest that reindeer may use a tolerance strategy to cope with gastrointestinal nematodes and raise the question as to whether moderate infection intensities with nematodes are beneficial to the host. By removing nematodes we may have altered the gut microbiota, leading to the observed elevated faecal glucocorticoid metabolite levels in the treated reindeer. These findings demonstrate the importance of considering both cortisol and corticosterone in physiological studies, as there is mounting evidence that they may have different functionalities. PMID:27957334

  7. Mercury accumulation in mallards fed methylmercury with or without added DDE. [Anas platyrhynchos

    SciTech Connect

    Heinz, G.H.

    1987-04-01

    Adult female mallards (Anas platyrhynchos) were fed a control diet or diets containing 1 ppm methylmercury chloride, 5 ppm methylmercurychloride, 1 ppm methylmercury chloride plus 5 ppm DDE, or 5 ppm methylmercury chloride plus 5 ppm DDE. The presence of DDE in the diet did not affect retention of mercury in breast muscle or eggs. There was a good correlation between the levels of mercury in the breast muscle of females and their eggs, and this correlation was unaffected by the presence of DDE in the diet. This correlation suggests that one could predict mercury levels in female mallards in the field when only eggs have been collected and vice versa.

  8. A comparison of levels of select minerals in scalp hair samples with estimated dietary intakes of these minerals in women of reproductive age.

    PubMed

    Suliburska, J

    2011-12-01

    The objective of this study was to evaluate daily intake of minerals and concentrations of minerals in hair in women of reproductive age. The study included 77 menstruating women, aged 35.9 ± 9.7 years. Subjects were divided into three groups according to age. All women were healthy. Hair samples were taken from several points of the occipital scalp. The content of minerals in hair samples was determined by flame atomic absorption spectrometry. Dietary intake of the analysed minerals was assayed on the basis of dietary intake interviews from three preceding days and evaluated using the dietetic computer programme. It was shown that calcium and iron daily intake by the women was below the recommended value. Only few women had low concentrations (below reference values) of magnesium, copper and zinc in hair. Statistically significant differences were shown between age groups. Generally, the concentrations of minerals in hair in the younger (19-30 years) and the older women (41-50 years) were higher than in hair of middle-aged women (31-40 years). The content of calcium, magnesium, iron and zinc in daily diets of women correlated inversely with copper level in their hair. Food products with good bioavailability of iron and calcium should be recommended for women of childbearing age in all age groups.

  9. Screening heavy metals levels in hair of sanitation workers by X-ray fluorescence analysis.

    PubMed

    Md Khudzari, Jauharah; Wagiran, Husin; Hossain, I; Ibrahim, Noorddin

    2013-01-01

    This work presents a study of human hair as a bio-indicator for detection of heavy metals as part of environmental health surveillance programs project to develop a subject of interest in the biomedical and environmental sciences. A total of 34 hair samples were analyzed that consisting of 29 samples from sanitation workers and five samples from students. The hair samples were prepared and treated in accordance to the International Atomic Energy Agency (IAEA) recommendations. The concentrations of heavy metals were analyzed using the energy dispersive X-ray fluorescence (EDXRF) technique by X-50 Mobile X-ray Fluorescence (XRF) at Oceanography Institute, Universiti Malaysia Terengganu. The performance of EDXRF analyzer was tested by Standard Reference Material (SRM 2711) Montana Soil which was in good agreement with certified value within 14% deviations except for Hg. While seven heavy metals: Mn, Fe, Ni, Cu, Zn, Se, and Sb were detected in both groups, three additional elements, i.e. As, Hg and Pb, were detected only in sanitation workers group. For sanitation workers group, the mean concentration of six elements, Mn, Fe, Cu, Zn, Se, and Sb, shows elevated concentration as compared to the control samples concentration. Results from both groups were compared and discussed in relation to their respective heavy metals concentrations.

  10. Mercury levels assessment in hair of riverside inhabitants of the Tapajós River, Pará State, Amazon, Brazil: fish consumption as a possible route of exposure.

    PubMed

    Faial, Kleber; Deus, Ricardo; Deus, Simonny; Neves, Ramiro; Jesus, Iracina; Santos, Elisabeth; Alves, Cláudio Nahum; Brasil, Davi

    2015-04-01

    The study present evaluated the levels of mercury (Hg) and methylmercury (MeHg) in hair samples of people from Barreiras community, riverside inhabitants of the Tapajós River (Pará, Brazil), an area impacted by clandestine gold mining, as well as we analyzed the levels of Hg and Se (selenium) in nine fish species (carnivores and non-carnivorous) from the Tapajós River, which stand out as the main species consumed by riverside inhabitants, to evaluate a relationship between frequency of fish consumption and Hg concentration, and also to evaluate possible mechanisms of fish protection (or non-protection) to Hg exposure by Se. Furthermore we analyze the water quality to evaluate the environmental trophic state, fact responsible by creating conditions that can potentiate the effects of toxic mercury. Concentrations of Hg and MeHg were analyzed in hair samples of 141 volunteers in different age band. Of those, 84.40% of samples present values above the threshold for biological tolerance, which is 6.00μgg(-1) of total Hg in hair. Total Hg, in men there was a variation of 2.07-24.93μgg(-1), while for women the variation was 4.84-27.02μgg(-1). Consequently, the level of MeHg in men presented a variation of 1.49-19.57μgg(-1), with an average of 11.68μgg(-1), while with women the variation was from 3.73 to 22.35μgg(-1), with an average of 10.38μgg(-1). In fish species, Hg concentrations in carnivorous species had an average of 0.66μgg(-1), higher than that permitted by current legislation, ranging from 0.30 to 0.98μgg(-1), while the non-carnivorous species have values below the recommended by the legislation averaging 0.09μgg(-1), ranging between 0.02 and 0.44μgg(-1). For Se in fish, show that among carnivores, the contents of Se ranged between 0.18 and 0.54μgg(-1) with a mean of 0.34μgg(-1), while for non-carnivores these values were of the order of 0.16-0.56μgg(-1), with an average of 0.32μgg(-1). In surface water quality variables at the sampling points

  11. Economic evaluation of health consequences of prenatal methylmercury exposure in France

    PubMed Central

    2012-01-01

    Background Evidence of a dose–response relationship between prenatal exposure to methylmercury (MeHg) and neurodevelopmental consequences in terms of IQ reduction, makes it possible to evaluate the economic consequences of MeHg exposures. Objective To perform an economic evaluation of annual national benefits of reduction of the prenatal MeHg exposure in France. Methods We used data on hair-Hg concentrations in French women of childbearing age (18–45 years) from a national sample of 126 women and from two studies conducted in coastal regions (n = 161and n = 503). A linear dose response function with a slope of 0.465 IQ point reduction per μg/g increase in hair-Hg concentration was used, along with a log transformation of the exposure scale, where a doubling of exposure was associated with a loss of 1.5 IQ points. The costs calculations utilized an updated estimate of €2008 17,363 per IQ point decrement, with three hypothetical exposure cut-off points (hair-Hg of 0.58, 1.0, and 2.5 μg/g). Results Because of higher exposure levels of women in coastal communities, the annual economic impacts based on these data were greater than those using the national data, i.e. € 1.62 billion (national), and € 3.02 billion and € 2.51 billion (regional), respectively, with the linear model, and € 5.46 billion (national), and € 9.13 billion and € 8.17 billion (regional), with the log model, for exposures above 0.58 μg/g. Conclusions These results emphasize that efforts to reduce MeHg exposures would have high social benefits by preventing the serious and lifelong consequences of neurodevelopmental deficits in children. PMID:22883022

  12. Effects of sex on the levels of metals and metalloids in the hair of a group of healthy Spanish adolescents (13 to 16 years old).

    PubMed

    Peña-Fernández, Antonio; Del Carmen Lobo-Bedmar, Maria; González-Muñoz, Maria José

    2017-08-31

    Human biomonitoring can be a reliable tool to protect the health of the citizens of major urban environments. Human hair may be an invaluable specimen to determine chronic exposure to any environmental contaminant in an individual, especially in the young population. However, different factors including a lack of studies that have established reference values for metals and metalloids (trace elements) in human scalp hair make the use of this matrix controversial. A monitoring study was performed to establish possible normal or tentative reference values of Al, As, Be, Cd, Cr, Cu, Hg, Mn, Pb, Sn, Ti, Tl and Zn in adolescents' (aged 13-16) hair who have lived since birth in Alcalá de Henares, Madrid region (Spain). Strict inclusion criteria were followed to study the effect of sex on the hair metal content, and the levels of the above contaminants were also studied in park topsoils from Alcalá de Henares. Scalp hair samples were collected from 96 healthy adolescents (28 boys and 68 girls), and reference values were calculated following the recommendations of the International Union of Pure and Applied Chemistry. The levels of Cd, Cu, Pb, Sn and Zn in hair of adolescents from Alcalá de Henares show a sex dependency, being significantly higher in female participants. Sex should be a factor taken into account when developing future reference values and hair metal content. Soil metal contamination was not correlated with the levels found in hair. To conclude, the values of metals and metalloids here analysed and discussed could be considered as tentative reference values for Spanish adolescents aged 13-16 years living in the Madrid region, and may be used to identify the level of exposure of adolescents in this Spanish region to the various metals and metalloids.

  13. Hair ethyl glucuronide levels as a marker for alcohol use and abuse: a review of the current state of the art.

    PubMed

    Crunelle, Cleo L; Yegles, Michel; Nuijs, Alexander L N van; Covaci, Adrian; De Doncker, Mireille; Maudens, Kristof E; Sabbe, Bernard; Dom, Geert; Lambert, Willy E; Michielsen, Peter; Neels, Hugo

    2014-01-01

    Ethyl glucuronide (EtG) is a minor alcohol metabolite that has been proposed as a stable marker in hair to detect and quantify alcohol consumption over long time periods. We provide an outline of currently available techniques for EtG hair sample analysis and highlight the pitfalls related to data interpretation. The literature of EtG analysis has been reviewed from January 1980 up to August 2013. In addition, we present an overview of the clinical and forensic studies which have used EtG quantification in hair as a marker for alcohol consumption/abstinence and we provide suggestions for future research. EtG is a stable marker in hair that can be used to detect and quantify alcohol consumption over long time periods. This alcohol metabolite remains in hair after complete elimination of alcohol. Currently, there are three main analytical techniques used to quantify EtG in hair: gas chromatography-mass spectrometry (GC-MS), gas chromatography-tandem mass spectrometry (GC-MS/MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). No standardized protocols are yet available for the analysis of EtG levels in hair samples, and the current protocols vary in sample preparation and extraction procedures. Variables such as hair length, cosmetic treatment, gender, and pathophysiological conditions influence the final results and should be taken into account. EtG quantification in hair is a useful tool for the objective detection of alcohol consumption over extended time periods, but care should be taken when interpreting the results. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Levels of heavy metals and essential minerals in hair samples of children with autism in Oman: a case-control study.

    PubMed

    Al-Farsi, Yahya M; Waly, Mostafa I; Al-Sharbati, Marwan M; Al-Shafaee, Mohammed A; Al-Farsi, Omar A; Al-Khaduri, Maha M; Gupta, Ishita; Ouhtit, Allal; Al-Adawi, Samir; Al-Said, Mona F; Deth, Richard C

    2013-02-01

    Toxic levels of heavy metals and low levels of essential minerals have been suggested to play a critical role in the pathogenesis of autism spectrum disorders (ASD). This study documents the levels of heavy metals and essential minerals in hair samples of children with ASD in Muscat, the urbanized capital of Oman, Muscat. The study included 27 children with ASD and 27 matched non-ASD controls. Parental interviews were held and dietary intake questionnaires completed in conjunction with the collection of hair samples. Analysis of heavy metals and essential minerals was carried out by inductively coupled plasma mass spectrometry. Chi-square analysis and non-parametric Fisher's exact tests were used to assess statistical significance. Children with ASD had significantly higher levels of all 11 analyzed heavy metals in their hair samples (P < 0.05), ranging from 150 to 365 % of control levels. ASD children also had significantly higher levels of essential minerals sulfur, sodium, magnesium, potassium, zinc, and iron, but lower levels of calcium and copper in their hair samples. This study corroborates data from previous studies in different parts of the world indicating the presence of elevated levels of heavy metals and selective depletion of essential minerals in the hair of children with ASD.

  15. Differences in mortality among bobwhite fed methylmercury chloride dissolved in various carriers

    USGS Publications Warehouse

    Spann, J.W.; Heinz, G.H.; Camardese, M.B.; Hill, E.F.; Moore, John F.; Murray, H.C.

    1986-01-01

    Twelve-day-old bobwhite chicks were fed a diet containing 0, 5.4 or 20 ppm methylmercury chloride. The methylmercury chloride was added to the diet either in a dry, pulverized form or dissolved in acetone, propylene glycol or corn oil. Mortality was measured for 6 weeks, and samples of liver were saved for mercury analysis. Mortality was significantly lower in birds fed 20 ppm methylmercury chloride when acetone was the solvent. The reduced mortality could not be explained by effects of acetone on dietary level of mercury or on uptake of mercury into the body.

  16. Voltammetric studies on the electrochemical determination of methylmercury in chloride medium at carbon microelectrodes.

    PubMed

    Ribeiro, F; Neto, M M M; Rocha, M M; Fonseca, I T E

    2006-10-10

    Electroanalytical techniques have been used to determine methylmercury at low levels in environmental matrices. The electrochemical behaviour of methylmercury at carbon microelectrodes in a hydrochloric acid medium using cyclic, square wave and fast-scan linear-sweep voltammetric techniques has been investigated. The analytical utility of the methylmercury reoxidation peak has been explored, but the recorded peak currents were found to be poorly reproducible. This is ascribed to two factors: the adsorption of insoluble chloromercury compounds on the electrode surface, which appears to be an important contribution to hinder the voltammetric signal of methylmercury; and the competition between the reoxidation of the methylmercury radical and its dimerization reaction, which limits the reproducibility of the methylmercury peak. These problems were successfully overcome by adopting the appropriate experimental conditions. Fast-scan rates were employed and an efficient electrochemical regeneration procedure of the electrode surface was achieved, under potentiostatic conditions in a mercury-free solution containing potassium thiocyanate--a strong complexing agent. The influence of chloride ion concentration was analysed. Interference by metals, such as lead and cadmium, was considered. Calibration plots were obtained in the micromolar and submicromolar concentration ranges, allowing the electrochemical determination of methylmercury in trace amounts. An estuarine water sample was analysed using the new method with a glassy carbon microelectrode.

  17. [Microcosm Simulation Study and Methylmercury Forming Mechanism at Landscape Water of City].

    PubMed

    Liu, Xiao-hong; Si, You-bin; Guo, Zi-wei; Du, Cheng-zhu; Zhu, Cong-cong

    2016-04-15

    Mercury is harmful to the environment, which has gradually become one of the research hotspots. Sediments, as a main repository of pollutants, have an important impact on water quality and the internal organisms, which deserves our research. In this paper, we focused on Hefei landscape water sediment and tried to investigate the status of inorganic mercury and methylmercury pollutions in the sediment. To study the conversion process from inorganic mercury to methylmercury and their enrichment levels and mechanism, we established the ecological chain of "sediment-water-grass-fish" through analog microcosm examination. The results were as follows: from ten water and sediment samples in Hefei landscape water sediment, we found that the contents of inorganic mercury and methylmercury ranged 11.74-13.12 µg · kg⁻¹ and 0.37-2.23 µg · kg⁻¹, respectively. The microcosm examination showed that: with increasing culture time, inorganic mercury in sediments gradually decreased. There was a phenomenon that the content of methylmercury increased at first and then decreased to reach the balance later. Both the inorganic mercury and methylmercury in water change showed an increasing trend. The enrichment contents of inorganic mercury in Egeria densa Planch, and golden mandarin fish (Siniperca scherzeri Steindachner) were low while their enrichment of methylmercury could he great. In addition, we found that both the bioaccumulation ability and the enrichment coefficient of methylmercury in the body of golden mandarin fish were the maximum during the same period.

  18. The proteomic profile of hair damage.

    PubMed

    Sinclair, R; Flagler, M J; Jones, L; Rufaut, N; Davis, M G

    2012-06-01

    Monilethrix is a congenital hair shaft disorder with associated fragility. Many of the changes seen in monilethrix hair on light microscopy and scanning electron microscopy are also seen in hair weathering and cosmetic damage to hair. We used monilethrix as a model to investigate the relationship between hair protein structure and hair strength and resistance to cosmetic insult. We applied proteomic techniques to identify novel peptide damage markers for chemical oxidative damage to hair. The findings suggest that specific sites in the protein structure of hair are targeted during oxidative damage from bleaching, a unique insight into how chemical damage compromises the structural integrity of the hair shaft at the molecular level. Applying proteomics to the study of congenital and acquired hair shaft disorders can deliver new insights into hair damage and novel strategies to strengthen hair. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

  19. Short Communication: A Low-Cost Method for Analyzing Nevirapine Levels in Hair as a Marker of Adherence in Resource-Limited Settings

    PubMed Central

    Yang, Qiyun; Bacchetti, Peter; Huang, Yong

    2014-01-01

    Abstract The measurement of antiretroviral concentrations in hair is emerging as an important technology to objectively quantify adherence to combination antiretroviral therapy. Hair levels of antiretrovirals are the strongest independent predictor of virologic success in large prospective cohorts of HIV-infected patients and surpass self-report in predicting outcomes. Hair is easy to collect and store, but validated methods to analyze antiretroviral levels in hair using liquid chromatography tandem mass spectrometry (LC-MS/MS) are expensive. We report here on the development of a thin-layer chromatography (TLC) assay for the semiquantitative analysis of nevirapine in hair. TLC assay results from 11 samples were consistent with results using LC-MS/MS [Spearman correlation coefficient 0.99 (95% CI 0.95–0.996)]. This simple, low-cost method of analyzing nevirapine concentrations in hair may provide a novel monitoring tool for antiretroviral adherence in resource-limited settings and merits further study in clinical settings. PMID:24164410

  20. Mercury in women exposed to methylmercury through fish consumption, and in their newborn babies and breast milk

    SciTech Connect

    Skerfving, S.

    1988-10-01

    The presence of methylmercury in fish is a major environmental problem. During the major epidemics of methylmercury poisoning through sea food in Minamata in Japan, and through dressed seed in Iraq, there was a high prevalence of infants, who developed cerebral palsy. This was generally assumed to be due to intrauterine methylmercury poisoning, as it is well known, that methylmercury is transferred through the placenta into the fetus. There is also a possibility that exposure occurred through breast milk, as high levels of mercury in breast milk have been reported in mothers from Minamata. Information on the relationship between methylmercury exposure, mercury levels in blood of mothers and their babies, and levels in breast milk are reported here.

  1. Dietary intake and serum and hair concentrations of minerals and their relationship with serum lipids and glucose levels in hypertensive and obese patients with insulin resistance.

    PubMed

    Suliburska, Joanna; Bogdański, Paweł; Pupek-Musialik, Danuta; Krejpcio, Zbigniew

    2011-02-01

    Inadequate minerals intake, as well as disruption of some metabolic processes in which microelements are cofactors, are suggested to lead to the development of hypertension. The role of minerals in the pathogenesis of hypertension still remains to be explained. In the present study, we sought to determine associations between serum and hair mineral concentrations and serum lipids and glucose levels. Forty obese hypertensive subjects with insulin resistance and 40 healthy volunteers were recruited in the study. Blood pressure, BMI, and insulin resistance were recorded in all subjects. Levels of lipids, glucose, sodium and potassium, iron, copper, zinc, magnesium, and calcium were assessed in serum. Iron, copper, zinc, magnesium, and calcium were assessed in hair. Dietary intake of the analyzed minerals was estimated. We found distinctly higher concentrations of serum iron and serum and hair calcium as well as markedly lower levels of hair zinc in the hypertensive subjects. The study group manifested also significantly lower daily intake of calcium, magnesium, and iron. We observed a relationship between the concentrations of iron, zinc, and copper in serum and hair and high and low range of cholesterol, triglycerides, and glucose serum levels in the studied patients. Moreover, this study demonstrated significant correlation between serum and hair concentrations of selected minerals and their dietary intake and levels of serum lipids and glucose and blood pressure in the study and the control groups. The obtained results seem to indicate the association between lipid and glucose metabolism and iron, copper, zinc, and calcium concentrations in blood and hair of hypertensive and obese patients with insulin resistance.

  2. Mercury contamination in human hair and some marine species from Sfax coasts of Tunisia: levels and risk assessment.

    PubMed

    Mezghani-Chaari, Sawssan; Hamza, A; Hamza-Chaffai, A

    2011-09-01

    The aim of this study was to measure the mercury (Hg) contents of three marine fish and common seafood species (Diplodus annularis, Sarpa salpa and Sepia officinalis) at two sampling sites in the gulf of Gabes, i.e. Sidi Mansour (polluted site) and Kerkennah (control site). These species are frequently consumed by the population living at the Sfax coasts of Tunisia, particularly by the families of fisherman. Additionally, the hair mercury levels of 55 volunteers (28 women, 27 men) were analysed and the daily total mercury intake through the fish and seafood diet was estimated. The key findings were: (1) the mercury contents of the examined fish and seafood species frequently exceeded the regulatory guideline value of 0.5 mg/kg, (2) no site-specific differences in hair mercury contents were found, (3) fish and seafood consumption is probably the major contributor of mercury exposure in this population, (4) the daily mercury intake through frequent consumption of D. annularis exceeds the US EPA reference dose. Further studies are necessary to evaluate the health risks associated with such high mercury exposure levels in order to allow optimal counseling and therapy of the concerned population and to avoid future impairment of human health, particularly children's health.

  3. Monitoring metals in the population living in the vicinity of a hazardous waste incinerator: levels in hair of school children.

    PubMed

    Nadal, Martí; Bocio, Ana; Schuhmacher, Marta; Domingo, Jose L

    2005-06-01

    Hair samples of 134 school children (12-14 yr old) living in three residential zones in the vicinity of a new hazardous waste incinerator (HWI) (Constanti, Tarragona County, Catalonia, Spain) were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) for arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), tin (Sn), thallium (Tl), and vanadium (V) concentrations. These concentrations were compared with those obtained in a baseline survey performed in the same area during the period of construction of the HWI. Current mean concentrations ranged from values under the respective limit of detection (As, Be, Cd, Tl, and V) to 0.70 and 0.86 microg/g for Hg and Pb, respectively. In comparison to the baseline survey, the levels of Cr, Mn, Ni, Pb, and Sn showed a significant reduction, whereas Hg concentrations were similar. No significant differences were observed according to the sex of the children. However, some differences were noted, especially for Pb and Cr, with respect to the specific zone of residence. In general terms, the current metal levels in hair of school children are similar or even lower than those recently reported for a number of industrial and residential areas of various regions and countries.

  4. Polymorphisms in glutathione-related genes modify mercury concentrations and antioxidant status in subjects environmentally exposed to methylmercury.

    PubMed

    Barcelos, Gustavo Rafael Mazzaron; Grotto, Denise; de Marco, Kátia Cristina; Valentini, Juliana; Lengert, André van Helvoort; de Oliveira, Andréia Ávila Soares; Garcia, Solange Cristina; Braga, Gilberto Úbida Leite; Schläwicke Engström, Karin; Cólus, Ilce Mara de Syllos; Broberg, Karin; Barbosa, Fernando

    2013-10-01

    Methylmercury (MeHg) toxicity may vary widely despite similar levels of exposure. This is hypothetically related to genetic differences in enzymes metabolizing MeHg. MeHg causes oxidative stress in experimental models but little is known about its effects on humans. The aims of the present study was to evaluate the effects of polymorphisms in glutathione (GSH)-related genes (GSTM1, GSTT1, GSTP1 and GCLM) on Hg concentrations in blood and hair, as well as MeHg-related effects on catalase (CAT) and glutathione-peroxidase (GPx) activity and GSH concentrations. Study subjects were from an Amazonian population in Brazil chronically exposed to MeHg from fish. Hg in blood and hair were determined by ICP-MS, CAT, GPx and GSH were determined by spectrophotometry, and multiplex PCR (GSTM1 and GSTT1) and TaqMan assays (GSTP1 and GCLM) were used for genotyping. Mean Hg concentrations in blood and hair were 48±36 μg/L and 14±10 μg/g. Persons with the GCLM-588 TT genotype had lower blood and hair Hg than did C-allele carriers (linear regression for Hg in blood β=-0.32, p=0.017; and hair β=-0.33; p=0.0090; adjusted for fish intake, age and gender). GSTM1*0 homozygous had higher blood (β=0.20; p=0.017) and hair Hg (hair β=0.20; p=0.013). Exposure to MeHg altered antioxidant status (CAT: β=-0.086; GSH: β=-0.12; GPx: β=-0.16; all p<0.010; adjusted for gender, age and smoking). Persons with GSTM1*0 had higher CAT activity in the blood than those with GSTM1. Our data thus indicate that some GSH-related polymorphisms, such as GSTM1 and GCLM may modify MeHg metabolism and Hg-related antioxidant effects.

  5. An archeological perspective on methylmercury exposure

    SciTech Connect

    Egeland, G.; Ponce, R.; Middaugh, J.

    1995-12-31

    Hair analyses of remains identified in Arctic archeological sites show that some individuals living in pre-industrial times would fall near or above current acceptable levels of MeHg exposure. For example, total mercury in hair was 4.8 ppm in the mummy of a 25 year-old found in Barrow, Alaska; in Greenland, the mean total hair Hg level of 15th century mummies was 3.1 ppm among six adults and 10 ppm among 2 children. In contrast, FDA`s recommended limit for MeHg in blood would translate to hair MeHg levels of 5 ppm. What are the methodological issues pertinent in interpreting these data and what are the implications of these data for current-day risk assessment and risk management related to the consumption of subsistence foods in the Arctic? How can archeological data help answer questions of relevance for subsistence populations of today? A program to examine pre-industrial MeHg levels in Alaska using human hair and animal fur from existing archeological collections has been initiated. Methodological issues will be discussed.

  6. Temporal Assessment of Methylmercury in an Endangered Pacific Seabird (Invited)

    NASA Astrophysics Data System (ADS)

    Vo, A. E.; Bank, M. S.; Shine, J. P.; Edwards, S. V.

    2010-12-01

    Methylmercury cycling in the Pacific Ocean has garnered significant attention in recent years, especially with regard to rising mercury emissions from Asia. Uncertainty exists over the extent to which mercury accumulation in biota may have resulted from increases in anthropogenic output over time. To address this, we assessed historical and recent mercury exposure in an endangered Pacific seabird, the Black-footed Albatross (Phoebastria nigripes), using feather samples from museum specimens spanning the past 130 years. We additionally analyzed stable isotopes of nitrogen (δ15N) and carbon (δ13C) to control for confounding factors of temporal change in trophic structure or diet. As a long-lived, wide-ranging, top marine predator and an endangered, keystone species in the North Pacific, the Black-footed Albatross comprises an ideal sentinel species for determining the effect of both global increases in mercury throughout the previous century and regional increases during the recent past on bioaccumulation and risk among avian wildlife. A significantly higher proportion of post-1940 samples contained above deleterious threshold levels (~40,000 ng/g) of methylmercury relative to pre-1940 samples, and mean concentrations were significantly higher in post-1990 than in pre-1990 samples. We also found increasingly higher amounts of (presumably curator-mediated) inorganic mercury contamination in older museum samples for the Black-footed Albatross as well as two non-pelagic comparison species, which informs future studies on bioaccumulation in museum specimens to analyze methylmercury rather than total mercury in all but recently collected specimens. Although complementary stable isotope data suggested no historic change in albatross trophic level, there was a significant change in δ13C signature over time. However, after controlling for these potential confounders, time significantly and positively associated with methylmercury exposure. Changes in methylmercury levels

  7. Hair transplant

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/007205.htm Hair transplant To use the sharing features on this page, please enable JavaScript. A hair transplant is a surgical procedure to improve baldness. Description ...

  8. Hair loss

    MedlinePlus

    ... continual hair pulling or scalp rubbing Radiation therapy Tinea capitis (ringworm of the scalp) Tumor of the ovary or ... a plucked hair Skin biopsy If you have ringworm on the scalp, you may be prescribed an ...

  9. Hair Removal

    MedlinePlus

    ... protection. In some cases, excess hair growth, called hirsutism (pronounced: hur -soo-tih-zum), may be the ... Some medications, like anabolic steroids, also can cause hirsutism. continue Getting Rid of Hair Shaving How It ...

  10. Study to determine the possible hazard of methylmercury in seafood to the fetus in utero. Final report, 1980-1985

    SciTech Connect

    Marsh, D.O.; Turner, M.D.; Smith, J.C.

    1985-12-01

    This study was conducted to determine the possible hazards of methylmercury (MeHg) in seafood to the fetus in utero. Hair and blood samples of pregnant women in New Bedford, MA, Manta, Ecuador, and Mancora, Peru (all areas of high seafood consumption) were examined. These samples were collected and studied at various stages of gestation and during pre- and post-natal periods. In some cases, blood and hair samples of some of the infants born to these women were also examined. The women of Manta and Mancora showed higher levels of MeHg than the women in New Bedford. However, no health hazards could be linked to any of the infants from the ingestion of MeHg in marine fish. Although no human data exist, experimental evidence suggests marine fish may contain elements that reduce the toxicity of MeHg and it's possible that selenium contributes to the protective effect of fish vs. grain diets. Tables of MeHg levels in the study groups are attached to the report.

  11. Biomagnifications of mercury and methylmercury in tuna and mackerel.

    PubMed

    Hajeb, P; Jinap, S; Ahmad, I

    2010-12-01

    Seawater may be contaminated by harmful substances, including toxic elements released by human activities. The present study evaluates the total mercury and methylmercury concentrations and their correlations to fish body size in longtail tuna and short-bodied mackerel from Chendring, Kuantan, at east coast and Kuala Perlis at west costs of Peninsular Malaysia during May to November 2007. Total mercury and methylmercury in muscle tissue of 69 samples of longtail tuna and short-bodied mackerel, ranged from 0.180 to 1.460 μg/g and 0.0.169-0.973 μg/g and 0.251-1.470 μg/g and 0.202-1.352, whereas the methylmercury to total mercury ratio ranged from 70% to 83%, respectively. Samples of both species from the east coast showed higher levels of mercury compared to those from west coast. In all of the locations, significant positive correlations were found between fish body weight and mercury content (R(2) > 0.470). The estimated weekly intake of total mercury and methylmercury from the consumption 66.33 g/week of short-bodied mackerel and 18.34 g/week of longtail tuna (based on local dietry survey) was found to be lower than the maximum limit of 5 and 1.5 μg/kg bodyweight established by FAO/WHO and codex, respectively.

  12. Hair cut

    NASA Image and Video Library

    2012-11-10

    ISS033-E-018986 (10 Nov. 2012) --- Russian cosmonaut Evgeny Tarelkin, Expedition 33 flight engineer, trims the hair of Russian cosmonaut Oleg Novitskiy, flight engineer, in the Tranquility node of the International Space Station. Tarelkin used hair clippers fashioned with a vacuum device to garner freshly cut hair. NASA astronaut Kevin Ford, flight engineer, is visible in the background.

  13. Hair cut

    NASA Image and Video Library

    2012-11-10

    ISS033-E-018991 (10 Nov. 2012) --- Russian cosmonaut Oleg Novitskiy, Expedition 33 flight engineer, trims the hair of Russian cosmonaut Evgeny Tarelkin, flight engineer, in the Tranquility node of the International Space Station. Novitskiy used hair clippers fashioned with a vacuum device to garner freshly cut hair.

  14. S-Mercuration of ubiquitin carboxyl-terminal hydrolase L1 through Cys152 by methylmercury causes inhibition of its catalytic activity and reduction of monoubiquitin levels in SH-SY5Y cells.

    PubMed

    Toyama, Takashi; Abiko, Yumi; Katayama, Yuko; Kaji, Toshiyuki; Kumagai, Yoshito

    2015-12-01

    Methylmercury (MeHg) is an environmental electrophile that covalently modifies cellular proteins. In this study, we identified proteins that undergo S-mercuration by MeHg. By combining two-dimensional SDS-PAGE, atomic absorption spectrometry and ultra performance liquid chromatography mass spectrometry (UPLC/MS/MS), we revealed that ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) is a target for S-mercuration in human neuroblastoma SH-SY5Y cells exposed to MeHg (1 µM, 9 hr). The modification site of UCH-L1 by MeHg was Cys152, as determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. MeHg was shown to inhibit the catalytic activity of recombinant human UCH-L1 in a concentration-dependent manner. Knockdown of UCH-L1 indicated that this enzyme plays a critical role in regulating mono-ubiquitin (monoUb) levels in SH-SY5Y cells and exposure of SH-SY5Y cells to MeHg caused a reduction in the level of monoUb in these cells. These observations suggest that UCH-L1 readily undergoes S-mercuration by MeHg through Cys152 and this covalent modification inhibits UCH-L1, leading to the potential disruption of the maintenance of cellular monoUb levels.

  15. Methylmercury: Reproductive and behavioral effects on three generations of mallard ducks

    USGS Publications Warehouse

    Heinz, G.H.

    1979-01-01

    Three generations of mallard ducks (Anas platyrhynchos) were fed either a control diet or a diet containing 0.5 ppm mercury in the form of methylmercury. The levels of mercury in adult tissues and eggs remained about the same over 3 generations. The methylmercury diet had no effect on adult weights or weight changes during the reproductive season. Females fed a diet containing 0.5 ppm mercury laid a greater percentage of their eggs outside their nestboxes than did controls, and also laid fewer eggs and produced fewer ducklings. Methylmercury in the diet appeared to result in a small amount of eggshell thinning. Ducklings from parents fed methylmercury were less responsive than, controls to tape-recorded maternal calls, but were hyper-responsive to a frightening stimulus in avoidance tests; there were no significant differences in locomotor activity in an open-field test.

  16. Floodplain methylmercury biomagnification factor higher than that of the contiguous river (South River, Virginia USA).

    PubMed

    Newman, Michael C; Xu, Xiaoyu; Condon, Anne; Liang, Lian

    2011-10-01

    Mercury biomagnification on the South River floodplain (Virginia, USA) was modeled at two locations along a river reach previously modeled for methylmercury movement through the aquatic trophic web. This provided an opportunity to compare biomagnification in adjoining trophic webs. Like the aquatic modeling results, methylmercury-based models provided better prediction than those for total mercury. Total mercury Food Web Magnification Factors (FWMF, fold per trophic level) for the two locations were 4.9 and 9.5. Methylmercury FWMF for the floodplain locations were higher (9.3 and 25.1) than that of the adjacent river (4.6). Previous speculation was not resolved regarding whether the high mercury concentrations observed in floodplain birds was materially influenced by river prey consumption by riparian spiders and subsequent spider movement into the trophic web of the adjacent floodplains. Results were consistent with a gradual methylmercury concentration increase from contaminated floodplain soil, to arthropod prey, and finally, to avian predators.

  17. [Hair loss].

    PubMed

    Trüeb, R M

    2003-09-03

    Hair loss includes excessive shedding of hair (effluvium) and the alopecias, in which there is a decrease in the amount of hair. Both may occur diffusely, or in a circumscribed manner. The localization and pattern of circumscribed hair loss may give a clue to its cause. On the basis of morphologic criteria the alopecias are further classified into non-scarring and scarring types. Non-scarring alopecias (diffuse alopecia, androgenetic alopecia, alopecia areata) are essentially hair cycling disorders, while scarring alopecias result from irreversible destruction of the hair follicles with recognizable loss of follicular osita. Scalp biopsy should be an early step in the evaluation of any case of alopecia, in which scarring is suspected. Too little scalp hair is not a vital problem, but represents a major health care challenge. Only recently the psychological impact of hair loss has been appreciated by the medical community, though throughout history, too little hair has been a concern to mankind, and the object of cosmetic interest and quackery. Recent advances of the medical sciences have led to a better understanding of the underlying pathogenic processes and opened the venue to effective pharmacotherapy (minoxidil, finasteride) and technologies (autologous hair transplantation) for the treatment of the most common disorders. Together with the availability of such treatments, high technical standards for evaluating their efficacy have been developed and have become mandatory for appraisal of any hair growth promoting agent, both in clinical studies and in the individual patient.

  18. Synergistic effects of mining and urban effluents on the level and distribution of methylmercury in a shallow aquatic ecosystem of the Bolivian Altiplano.

    PubMed

    Alanoca, L; Guédron, S; Amouroux, D; Audry, S; Monperrus, M; Tessier, E; Goix, S; Acha, D; Seyler, P; Point, D

    2016-12-08

    Lake Uru Uru (3686 m a.s.l.) located in the Bolivian Altiplano region receives both mining effluents and urban wastewater discharges originating from the surrounding local cities which are under rapid development. We followed the spatiotemporal distribution of different mercury (Hg) compounds and other metal(oid)s (e.g., Fe, Mn, Sb, Ti and W) in both water and sediments during the wet and dry seasons along a north-south transect of this shallow lake system. Along the transect, the highest Hg and metal(oid) concentrations in both water and sediments were found downstream of the confluences with mining effluents. Although a dilution effect was found for major elements during the wet season, mean Hg and metal(oid) concentrations did not significantly differ from the dry season due to the increase in acid mine drainage (AMD) inputs into the lake from upstream mining areas. In particular, high filtered (<0.45 μm) mono-methylmercury (MMHg) concentrations (0.69 ± 0.47 ng L(-1)) were measured in surface water representing 49 ± 11% of the total filtered Hg concentrations (THgF) for both seasons. Enhanced MMHg lability in relation with the water alkalinity, coupled with abundant organic ligands and colloids (especially for downstream mining effluents), are likely factors favoring Hg methylation and MMHg preservation while inhibiting MMHg photodegradation. Lake sediments were identified as the major source of MMHg for the shallow water column. During the dry season, diffusive fluxes were estimated to be 227 ng m(-2) d(-1) for MMHg. This contribution was found to be negligible during the wet season due to a probable shift of the redox front downwards in the sediments. During the wet season, the results obtained suggest that various sources such as mining effluents and benthic or macrophytic biofilms significantly contribute to MMHg inputs in the water column. This work demonstrates the seasonally dependent synergistic effect of AMD and urban effluents on the shallow

  19. Methylmercury dose estimation from umbilical cord concentrations in patients with Minamata disease.

    PubMed

    Akagi, H; Grandjean, P; Takizawa, Y; Weihe, P

    1998-05-01

    The methylmercury exposure of patients with congenital or infantile Minamata disease is known only from a small number of analyses of umbilical cords. Four laboratories in Japan have analyzed a total of 176 samples of umbilical cord tissue obtained from Minamata. The highest concentrations were seen in cord tissue from children born during 1950-1965, i.e., the peak period of acetaldehyde production in Minamata before installation of waste water treatment. Twenty-four samples from patients diagnosed with Minamata disease showed a median mercury concentration of 1.63 microg/g and differed significantly from levels seen in cord tissue from control children. However, children diagnosed with mental retardation had mercury concentrations in cord that were intermediate between the two other groups. Using regression coefficients obtained at a study conducted at the Faroe Islands, the median cord mercury concentration from the children with Minamata disease is estimated to correspond to about 216 microg/L cord blood and 41 microg/g in maternal hair. Based on correlations reported in the literature, the median daily mercury intake of the women whose children developed Minamata disease can then be estimated at about 225 microg. Although these children had fully developed Minamata disease, the estimates of median mercury levels are only four to five times higher than current mercury exposure limits.

  20. The US EPA reference dose for methylmercury: sources of uncertainty.

    PubMed

    Rice, Deborah C

    2004-07-01

    The US Environmental Protection Agency (EPA) derived a reference dose for methylmercury in 2001, based on an extensive analysis by the National Research Council (NRC) of the National Academy of Sciences. The NRC performed benchmark dose analysis on a number of endpoints from three longitudinal prospective studies: the Seychelles Islands, the Faroe Islands, and the New Zealand studies. Adverse effects were reported in the latter two studies, but not in the Seychelles study. The NRC also performed an integrative analysis of all three studies. Dose conversion from cord blood or maternal hair mercury concentration was performed by EPA using a one-compartment pharmacokinetic model. A total uncertainty factor of 10 was applied for intrahuman pharmacokinetic and pharmacodynamic variability. There are numerous decisions made by the NRC/EPA that could greatly affect the value of the reference dose (RfD). Some of these include the choice of a linear model for the relationship between mercury body burden and neuropsychological performance, the choice of values of P0 and the benchmark response, the use of the "critical study/critical endpoint" approach in the interpretation of the maternal body burden that corresponds to the RfD, the use of central tendencies in a one-compartment pharmacokinetic model rather than the inclusion of the distributions of variables for the population of reproductive-age women, the assumption of unity for the ratio of fetal cord blood to maternal blood methylmercury concentrations, the choice of a total of 10 as an uncertainty factor, and the lack of dose-response analysis for other health effects such as cardiovascular disease. In addition, it may be argued that derivation of a RfD for methylmercury is inappropriate, given that there does not appear to be a threshold for adverse neuropsychological effects based on available data.

  1. Neonatal Hair Nicotine Levels and Fetal Exposure to Paternal Smoking at Home

    PubMed Central

    Seong, Moon-Woo; Hwang, Jong Hee; Moon, Jin Soo; Ryu, Hye-Jung; Kong, Sun-Young; Um, Tae Hyun; Park, Jae-Gahb

    2008-01-01

    Exposure to environmental tobacco smoke (ETS) is a major risk to human health, and the home is the greatest single source of ETS for children. The authors investigated fetal exposure to paternal smoking at home during pregnancy. Korean families were included as trios of fathers, mothers, and neonates identified in 2005–2007. Sixty-three trios were finally enrolled in this study after exclusion of those in which the mother was a smoker or was regularly exposed to ETS at places other than the home. Nicotine and cotinine concentrations in hair were measured by using liquid chromatography–tandem mass spectrometry to determine long-term exposure to ETS. The difference between neonatal nicotine concentrations in the smoker and nonsmoker groups was not statistically significant. However, in the indoor-smoker group, neonatal nicotine concentrations were significantly higher than in the outdoor and nonsmoker groups (P < 0.05). Furthermore, neonatal nicotine concentrations in the outdoor-smoker group were not different from those in the nonsmoker group. These findings indicate that paternal smoking inside the home leads to significant fetal and maternal exposure to ETS and may subsequently affect fetal health. Conversely, findings show that paternal smoking outside the home prevents the mother and her fetus from being exposed to ETS. PMID:18801888

  2. Neurobehavioral effects of developmental methylmercury exposure

    SciTech Connect

    Gilbert, S.G.; Grant-Webster, K.S.

    1995-09-01

    Methylmercury (MeHg) is a global environmental problem and is listed by the International Program of Chemical Safety as one of the six most dangerous chemicals in the world`s environment. Human exposure to MeHg primarily occurs through the consumption of contaminated food such as fish, although catastrophic exposures due to industrial pollution have occurred. The fetus is particularly sensitive to MeHg exposure and adverse effects on infant development have been associated with levels of exposure that result in few, if any, signs of maternal clinical illness or toxicity. High levels of prenatal exposure in humans result in neurobehavioral effects such as cerebral palsy and severe mental retardation. Prenatal exposure to MeHg in communities with chronic low-level exposure is related to decreased birthweight and early sensorimotor dysfunction such as delayed onset of walking. Neurobehavioral alterations have also been documented in studies with non human primates and rodents. Available information on the developmental neurotoxic effects of MeHg, particularly the neurobehavioral effects, indicates that the fetus and infant are more sensitive to adverse effects of MEHg. It is therefore recommended that pregnant women and women of childbearing age be strongly advised to limit their exposure to potential sources of MeHg. Based on results from human and animal studies on the developmental neurotoxic effects of methylmercury, the accepted reference dose should be lowered to 0.025 to 0.06 MeHg {mu}g/kg/day. Continued research on the neurotoxic effects associated with low level developmental exposure is needed. 107 refs., 3 tabs.

  3. Neurobehavioral effects of developmental methylmercury exposure.

    PubMed Central

    Gilbert, S G; Grant-Webster, K S

    1995-01-01

    Methylmercury (MeHg) is a global environmental problem and is listed by the International Program of Chemical Safety as one of the six most dangerous chemicals in the world's environment. Human exposure to MeHg primarily occurs through the consumption of contaminated food such as fish, although catastrophic exposures due to industrial pollution have occurred. The fetus is particularly sensitive to MeHg exposure and adverse effects on infant development have been associated with levels of exposure that result in few, if any, signs of maternal clinical illness or toxicity. High levels of prenatal exposure in humans result in neurobehavioral effects such as cerebral palsy and severe mental retardation. Prenatal exposure to MeHg in communities with chronic low-level exposure is related to decreased birthweight and early sensorimotor dysfunction such as delayed onset of walking. Neurobehavioral alterations have also been documented in studies with nonhuman primates and rodents. Available information on the developmental neurotoxic effects of MeHg, particularly the neurobehavioral effects, indicates that the fetus and infant are more sensitive to adverse effects of MeHg. It is therefore recommended that pregnant women and women of childbearing age be strongly advised to limit their exposure to potential sources of MeHg. Based on results from human and animal studies on the developmental neurotoxic effects of methylmercury, the accepted reference dose should be lowered to 0.025 to 0.06 MeHg microgram/kg/day. Continued research on the neurotoxic effects associated with low level developmental exposure is needed. PMID:8549462

  4. [Methylmercury: existing recommendations; methods of analysing and interpreting the results; economic evaluation].

    PubMed

    González-Estecha, Montserrat; Bodas-Pinedo, Andrés; Martínez-García, María José; Trasobares-Iglesias, Elena M; Bermejo-Barrera, Pilar; Ordóñez-Iriarte, José María; Llorente-Ballesteros, María Teresa; Prieto-Menchero, Santiago; Guillén-Pérez, José Jesús; Martell-Claros, Nieves; Cuadrado-Cenzual, María Ángeles; Rubio-Herrera, Miguel Ángel; Martínez-Álvarez, Jesús Román; Calvo-Manuel, Elpidio; Farré-Rovira, Rosaura; Herráiz-Martínez, Miguel Ángel; Bretón Lesmes, Irene; García-Donaire, José Antonio; Sáinz-Martín, María; Martínez-Astorquiza, Txantón; Gallardo-Pino, Carmen; Moreno-Rojas, Rafael; Salas-Salvadó, Jordi; Blanco Fuentes, María; Arroyo-Fernández, Manuel; Calle Pascual, Alfonso

    2014-11-04

    The beneficial effects of fish consumption are well- known. Nevertheless, there is worldwide concern regard methylmercury concentrations in fish, which is why many countries such as the United States, Australia, New Zealand, Canada and numerous European countries have made fish consumption recommendations for their populations, particularly vulnerable groups, in order to México methylmercury intake. Blood and hair are the best biological samples for measuring methylmercury. The most widely-used method to analyse methylmercury is cold vapor atomic absorption spectrometry, although there are also direct methods based on the thermal decomposition of the sample. In recent years, the number of laboratories that measure mercury by inductively coupled plasma mass spectrometry has increased. In addition, the different kinds of mercury can be distinguished by coupling chromatography methods of separation. Laboratories that analyse mercury in biological samples need to participate in external quality control programmes. Even if mercury emissions are reduced, mercury may remain in the environment for many years, so dietary recommendations are fundamental in order to reduce exposure. It is necessary to propose public health measures aimed at decreasing mercury exposure and to evaluate the benefits of such measures from the economic and social standpoints.

  5. Eggshell thickness in mallards fed methylmercury

    SciTech Connect

    Heinz, G.H.

    1980-09-01

    Eggshell thinning has been linked to impaired reproduction in many wild birds. Previous work of my own and others led me to believe that methylmercury may cause some eggshell thinning in birds. The present study was designed to determine whether methylmercury in the diet of mallards would thin their eggshells and whether it would add to eggshell thinning caused by DDE.

  6. Variation in the Levels of Aluminum and Manganese in Scalp Hair Samples of the Patients Having Different Psychiatric Disorders with Related to Healthy Subjects.

    PubMed

    Arain, Mariam S; Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Atif; Naeemullah; Ali, Jamshed; Arain, Salma Aslam; Panhwar, Abdul Haleem

    2015-11-01

    There is very limited information available on the role of trace elements in psychiatric disorders (PSD). Immense pieces of evidence support the idea that exposure to trace and toxic metals, such as aluminum (Al) and manganese (Mn), may be factors or cofactors in the etiopathogenesis of a variety of psychiatric disorders. The aim of our study was to assess the Al and Mn in scalp hair samples of 102 patients having different types of psychiatric disorder PSD diseases together with 120 referent subjects of male patients in the age group of 45-60 years. The understudy elements in scalp hair samples were assessed by the flame atomic absorption spectrophotometry after microwave-assisted acid digestion method .The validity of methodology was checked by the certified human hair reference material (NCS ZC81002). The recovery of studied elements was found in the range of 98.1-99.2 % of certified reference material. The results of this study showed that the mean values of Al and Mn were significantly higher in scalp hair samples of all types of PSD as compared to referents subjects. The resulted data indicated a significant increase in the contents of Mn and Al in scalp hair samples of psychiatric patients than that of its control counterpart, which may provide prognostic tool for the diagnosis of the mental disorders. However, further work is suggested to examine the exact correlation between trace elements level and the degree of disorder.

  7. Methylmercury exposure and mortality in Japan: a life table analysis

    SciTech Connect

    Tamashiro, H.; Fukutomi, K.; Lee, E.S.

    1987-03-01

    The effects on life expectancy from elevated methylmercury (MeHg) exposure were studied in five coastal towns of southern Japan. Hair concentrations of MeHg in the study area were 3 to 6 times higher than the surrounding areas. From 1969-1972 to 1978-1982 life expectancy increased in the study area, with no appreciable difference between that area and the two control areas. When four major causes of death were deleted analytically in both study and control areas, malignant neoplasms contributed the most in recent years to potential gains in life expectancy for both sexes. For the duration of their working ages, however, accidents were the leading contributor for males, followed by malignant neoplasms, heart disease, and cerebrovascular disease. The relative contribution of these causes of death to gain in life expectancy in the study area population is discussed in the context of elevated MeHg exposure.

  8. Tryptophan in human hair: correlation with pigmentation.

    PubMed

    Bertazzo, A; Biasiolo, M; Costa, C V; Cardin de Stefani, E; Allegri, G

    2000-08-01

    The distribution of tryptophan content in human hair of various colours was evaluated, in order to study the accumulation of this amino acid, precursor of serotonin, melatonin and niacin, in hair and the influence on hair pigmentation. Pigmentation is an important factor in determining drug incorporation into hair. Results from 1211 samples of hair from healthy subjects (577 men and 634 women) show that tryptophan levels are significantly higher in males (37.83 +/- 3.45 microg/g dry hair) than in females (26.62 +/- 2.40 microg/g hair). Besides sex, age also influences the distribution of tryptophan in human hair, the highest levels being found in both sexes in the first few years of life, probably due to the influence of milk, and in aging subjects in the groups of 61-80 and > 80 years. In order to investigate the influence of hair colour, hair samples were subdivided according to colour into blond, dark blond, red, light brown, brown, black, grey and white. The hair contents of tryptophan in both sexes was higher in brown and black hair than in blond hair, but in grey and white hair concentrations were the highest, demonstrating that tryptophan accumulates among hair fibres with age. Grouping subjects by age in relation to hair colour, we observed that at ages 1-5 and 6-12 years, colour did not influence tryptophan contents, but at ages 13-19 and 20-40 years tryptophan content increased significantly from blond to brown at 13-19 years and from blond to black at 20-40 years in both sexes. Therefore, variations in tryptophan levels of human hair appear to be correlated with differences in hair colour in both sexes. Tryptophan also accumulates in hair during keratinization, as shown by the presence of high levels of this amino acid in grey and white hair.

  9. Root Hairs

    PubMed Central

    Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

  10. Phytoremediation of ionic and methylmercury pollution

    SciTech Connect

    Meagher, Richard B

    2010-04-28

    Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and sequester the toxic elemental pollutants, like the heavy metal mercury. Our current working hypothesis is that transgenic plants controlling the transport, chemical speciation, electrochemical state. volatilization, and aboveground binding of mercury will: a) tolerate mercury and grow rapidly in mercury contaminated environments; b) prevent methylmercury from entering the food chain; c) remove mercury from polluted soil and . water; and d) hyperaccumulate mercury in aboveground tissues for later harvest. Progress toward these specific aims is reported: to increase the transport of mercury into roots and to aboveground vegetative organs; to increase biochemical sinks and storage for mercury in leaves; to increase leaf cell vacuolar storage of mercury; and to demonstrate that several stacked transgenes, when functioning in concert, enhance mercury resistance and hyperaccumulation to high levels.

  11. Maternal methylmercury exposure through rice ingestion and offspring neurodevelopment: A prospective cohort study.

    PubMed

    Rothenberg, Sarah E; Yu, Xiaodan; Liu, Jihong; Biasini, Fred J; Hong, Chuan; Jiang, Xu; Nong, Yanfen; Cheng, Yue; Korrick, Susan A

    2016-11-01

    Dietary methylmercury intake can occur not only through fish ingestion but also through rice ingestion; however, rice does not contain the same beneficial micronutrients as fish. In rural China, where rice is a staple food, associations between prenatal methylmercury exposure (assessed using maternal hair mercury) and impacts on offspring neurodevelopment were investigated. A total of 398 mothers were recruited at parturition at which time a sample of scalp hair was collected. Offspring (n=270, 68%) were assessed at 12 months using the Bayley Scales of Infant Development-II, yielding age-adjusted scores for the Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI). Among 270 mothers, 85% ingested rice daily, 41% never or rarely ingested fish/shellfish and 11% ingested fish/shellfish at least twice/weekly. Maternal hair mercury averaged 0.41μg/g (median: 0.39μg/g, range: 0.079-1.7μg/g). In unadjusted models, offspring neurodevelopment (both MDI and PDI) was inversely correlated with hair mercury. Associations were strengthened after adjustment for fish/shellfish ingestion, rice ingestion, total energy intake (kcal), and maternal/offspring characteristics for both the MDI [Beta: -4.9, 95% Confidence Interval (CI): -9.7, -0.12] and the PDI (Beta: -2.7, 95% CI: -8.3, 2.9), although confidence intervals remained wide for the latter. For 12-month old offspring living in rural China, prenatal methylmercury exposure was associated with statistically significant decrements in offspring cognition, but not psychomotor development. Results expose potential new vulnerabilities for communities depending on rice as a staple food. Copyright © 2016 Elsevier GmbH. All rights reserved.

  12. Hair Follicle Pigmentation

    PubMed Central

    Slominski, Andrzej; Wortsman, Jacobo; Plonka, Przemyslaw M.; Schallreuter, Karin U.; Paus, Ralf; Tobin, Desmond J.

    2005-01-01

    Hair shaft melanin components (eu- or/and pheomelanin) are a long-lived record of precise interactions in the hair follicle pigmentary unit, e.g., between follicular melanocytes, keratinocytes, and dermal papilla fibroblasts. Follicular melanogenesis (FM) involves sequentially the melanogenic activity of follicular melanocytes, the transfer of melanin granules into cortical and medulla keratinocytes, and the formation of pigmented hair shafts. This activity is in turn regulated by an array of enzymes, structural and regulatory proteins, transporters, and receptors and their ligands, acting on the developmental stages, cellular, and hair follicle levels. FM is stringently coupled to the anagen stage of the hair cycle, being switched-off in catagen to remain absent through telogen. At the organ level FM is precisely coupled to the life cycle of melanocytes with changes in their compartmental distribution and accelerated melanoblast/melanocyte differentiation with enhanced secretory activity. The melanocyte compartments in the upper hair follicle also provides a reservoir for the repigmentation of epidermis and, for the cyclic formation of new anagen hair bulbs. Melanin synthesis and pigment transfer to bulb keratinocytes are dependent on the availability of melanin precursors, and regulation by signal transduction pathways intrinsic to skin and hair follicle, which are both receptor dependent and independent, act through auto-, para- or intracrine mechanisms and can be modified by hormonal signals. The important regulators are MC1 receptor its and adrenocorticotropic hormone, melanocyte stimulating hormone, agouti protein ligands (in rodents), c-Kit, and the endothelin receptors with their ligands. Melanin itself has a wide range of bioactivities that extend far beyond its determination of hair color. PMID:15654948

  13. Genetic polymorphisms are associated with hair, blood, and urine mercury levels in the American Dental Association (ADA) study participants.

    PubMed

    Parajuli, Rajendra Prasad; Goodrich, Jaclyn M; Chou, Hwai-Nan; Gruninger, Stephen E; Dolinoy, Dana C; Franzblau, Alfred; Basu, Niladri

    2016-08-01

    Mercury (Hg) is a potent toxicant of concern to the general public. Recent studies suggest that several genes that mediate Hg metabolism are polymorphic. We hypothesize that single nucleotide polymorphisms (SNPs) in such genes may underline inter-individual differences in exposure biomarker concentrations. Dental professionals were recruited during the American Dental Association (ADA) 2012 Annual Meeting. Samples of hair, blood, and urine were collected for quantifying Hg levels and genotyping (88 SNPs in classes relevant to Hg toxicokinetics including glutathione metabolism, selenoproteins, metallothioneins, and xenobiotic transporters). Questionnaires were administrated to obtain information on demographics and sources of Hg exposure (e.g., fish consumption and use of dental amalgam). Here, we report results for 380 participants with complete genotype and Hg biomarker datasets. ANOVA and linear regressions were used for statistical analysis. Mean (geometric) Hg levels in hair (hHg), blood (bHg), urine (uHg), and the average estimated Hg intake from fish were 0.62µg/g, 3.75µg/L, 1.32µg/L, and 0.12µg/kg body weight/day, respectively. Out of 88 SNPs successfully genotyped, Hg biomarker levels differed by genotype for 25 SNPs, one of which remained significant following Bonferroni correction in ANOVA. When the associations between sources of Hg exposure and SNPs were analyzed with respect to Hg biomarker concentrations, 38 SNPs had significant main effects and/or gene-Hg exposure source interactions. Twenty-five, 23, and four SNPs showed significant main effects and/or interactions for hHg, bHg, and uHg levels, respectively (p<0.05), and six SNPs (in GCLC, MT1M, MT4, ATP7B, and BDNF) remained significant following Bonferroni correction. The findings suggest that polymorphisms in environmentally-responsive genes can influence Hg biomarker levels. Hence, consideration of such gene-environment factors may improve the ability to assess the health risks of Hg more

  14. Genetic Polymorphisms are Associated with Hair, Blood, and Urine Mercury Levels in the American Dental Association (ADA) Study Participants

    PubMed Central

    Parajuli, Rajendra Prasad; Goodrich, Jaclyn M.; Chou, Hwai-Nan; Gruninger, Stephen E.; Dolinoy, Dana C.; Franzblau, Alfred; Basu, Niladri

    2015-01-01

    Background/Aims Mercury (Hg) is a potent toxicant of concern to the general public. Recent studies suggest that several genes that mediate Hg metabolism are polymorphic. We hypothesize that single nucleotide polymorphisms (SNPs) in such genes may underline inter-individual differences in exposure biomarker concentrations. Methods Dental professionals were recruited during the American Dental Association (ADA) 2012 Annual Meeting. Samples of hair, blood, and urine were collected for quantifying Hg levels and genotyping (88 SNPs in classes relevant to Hg toxicokinetics including glutathione metabolism, selenoproteins, metallothioneins, and xenobiotic transporters). Questionnaires were administrated to obtain information on demographics and sources of Hg exposure (e.g., fish consumption and use of dental amalgam). Here, we report results for 380 participants with complete genotype and Hg biomarker datasets. ANOVA and linear regressions were used for statistical analysis. Results Mean (geometric) Hg levels in hair (hHg), blood (bHg), urine (uHg), and the average estimated Hg intake from fish were 0.62μg/g, 3.75μg/L, 1.32μg/L, and 0.12μg/kg body weight/day, respectively. Out of 88 SNPs successfully genotyped, Hg biomarker levels differed by genotype for 25 SNPs, one of which remained significant following Bonferroni correction in ANOVA. When the associations between sources of Hg exposure and SNPs were analyzed with respect to Hg biomarker concentrations, 38 SNPs had significant main effects and/or gene-Hg exposure source interactions. Twenty-five, 23, and four SNPs showed significant main effects and/or interactions for hHg, bHg, and uHg levels, respectively (p<0.05), and six SNPs (in GCLC, MT1M, MT4, ATP7B, and BDNF) remained significant following Bonferroni correction. Conclusion The findings suggest that polymorphisms in environmentally-responsive genes can influence Hg biomarker levels. Hence, consideration of such gene-environment factors may improve the

  15. Evaluated the levels of lead and cadmium in scalp hair of adolescent boys consuming different smokeless tobacco products with related to controls.

    PubMed

    Arain, Sadaf S; Kazi, Tasneem G; Arain, Asma J; Afridi, Hassan I; Brahman, Kapil D; Naeemullah; Ali, Jamshed; Memon, G Zuhra

    2015-04-01

    The present study was aimed to evaluate the cadmium (Cd) and lead (Pb) levels in the scalp hair samples of adolescent boys age ranged 12-15 years, chewing different smokeless tobacco (SLT) products. For comparative purpose, boys of the same age group who did not consume any SLT products were selected as referents. The concentrations of Cd and Pb in SLT products and the scalp hair samples were measured by electrothermal atomic absorption spectrophotometer (ETAAS) after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by certified reference materials (CRMs). The difference between experimental and certified values of both elements was not significant (p > 0.05). The resulted data indicated that the adolescent boys who consumed different SLT products have two- to threefold higher levels of Cd and Pb in the scalp hair samples as compared to the referent boys (p < 0.01). The adolescent chewing different SLT products have 82.2-110 and 60.6-94.5% higher levels of Cd and Pb, respectively, in their scalp hair as related to the referents.

  16. Thyroid Hormones and Methylmercury Toxicity

    PubMed Central

    O’Mara, Daniel M.; Aschner, Michael

    2013-01-01

    Thyroid hormones are essential for cellular metabolism, growth, and development. In particular, an adequate supply of thyroid hormones is critical for fetal neurodevelopment. Thyroid hormone tissue activation and inactivation in brain, liver, and other tissues is controlled by the deiodinases through the removal of iodine atoms. Selenium, an essential element critical for deiodinase activity, is sensitive to mercury and, therefore, when its availability is reduced, brain development might be altered. This review addresses the possibility that high exposures to the organometal, methylmercury (MeHg), may perturb neurodevelopmental processes by selectively affecting thyroid hormone homeostasis and function. PMID:18716716

  17. Diffuse alopecia areata is associated with intense inflammatory infiltration and CD8+ T cells in hair loss regions and an increase in serum IgE level.

    PubMed

    Zhao, Ying; Zhang, Bin; Caulloo, Sillani; Chen, Xiaohong; Li, Yang; Zhang, Xingqi

    2012-01-01

    Mechanism leading to an abrupt hair loss in diffuse alopecia areata (AA) remains unclear. To explore the characteristics of diffuse AA and possible factors involved in its pathogenesis. Clinical and laboratory data of 17 diffuse AA patients and 37 patchy AA patients were analyzed retrospectively. Serum IgE level was evaluated in all diffuse and patchy AA patients, as well as 27 healthy subjects without hair loss to serve as normal control. Univariate analysis was performed using Fisher's exact test and Wilcoxon rank-sum test. Associations between inflammatory cell infiltration and laboratory values were analyzed using Spearman rank correlation test. The mean age of patients with diffuse AA was 27 years with a mean disease duration of 1.77 months. All of them presented in spring or summer with an acute onset of diffuse hair loss preceded by higher incidence of scalp pruritus. Although no statistically significant difference on the incidence of atopic disease among three groups has been found, serum IgE level in diffuse AA was higher than that in healthy controls, but was comparable to that in patchy AA group. Histopathology of lesional scalp biopsies showed more intense infiltration comprising of mononuclear cells, eosinophils, CD3 + , and CD8 + T cells around hair bulbs in diffuse AA group than in patchy AA group. Moreover, IgE level in diffuse AA patients positively correlated with intensity of infiltration by mononuclear cells, eosinophils, and CD8 + T cells. Hypersensitivity may be involved in pathogenesis of diffuse AA. The acute onset of diffuse AA may be related to intense local inflammatory infiltration of hair loss region and an increase in serum IgE level.

  18. Body Hair

    MedlinePlus

    ... stop hair growth. The laser light can cause pain sometimes, but creams are used to numb the skin. If you use a lot of these creams, they can cause serious health problems, so talk to your doctor before having laser hair removal. Avoid sunlight when your skin is healing after laser removal. ...

  19. Hair Loss

    MedlinePlus

    ... lupus. If you take certain medicines or have chemotherapy for cancer, you may also lose your hair. Other causes are stress, a low protein diet, a family history, or poor nutrition. Treatment for hair loss depends on the cause. In some cases, treating ...

  20. Methylmercury degradation by Pseudomonas putida V1.

    PubMed

    Cabral, Lucélia; Yu, Ri-Qing; Crane, Sharron; Giovanella, Patricia; Barkay, Tamar; Camargo, Flávio A O

    2016-08-01

    Environmental contamination of mercury (Hg) has caused public health concerns with focuses on the neurotoxic substance methylmercury, due to its bioaccumulation and biomagnification in food chains. The goals of the present study were to examine: (i) the transformation of methylmercury, thimerosal, phenylmercuric acetate and mercuric chloride by cultures of Pseudomonas putida V1, (ii) the presence of the genes merA and merB in P. putida V1, and (iii) the degradation pathways of methylmercury by P. putida V1. Strain V1 cultures readily degraded methylmercury, thimerosal, phenylmercury acetate, and reduced mercuric chloride into gaseous Hg(0). However, the Hg transformation in LB broth by P. putida V1 was influenced by the type of Hg compounds. The merA gene was detected in P. putida V1, on the other hand, the merB gene was not detected. The sequencing of this gene, showed high similarity (100%) to the mercuric reductase gene of other Pseudomonas spp. Furthermore, tests using radioactive (14)C-methylmercury indicated an uncommon release of (14)CO2 concomitant with the production of Hg(0). The results of the present work suggest that P. putida V1 has the potential to remove methylmercury from contaminated sites. More studies are warranted to determine the mechanism of removal of methylmercury by P. putida V1.

  1. Ingrowing Hair

    PubMed Central

    Luo, Di-Qing; Liang, Yu-Hua; Li, Xi-Qing; Zhao, Yu-Kun; Wang, Fang; Sarkar, Rashmi

    2016-01-01

    Abstract Cutaneous pili migrans and creeping eruption caused by parasitic diseases may present as a moving linear lesion in skin. The former, caused by a hair shaft or fragment embedded in the superficial skin or middle dermis, is a rare condition characterized by creeping eruption with a black line observed at the advancing end. In exceptionally rare instance, the hair grows inside the skin and burrows in the uppermost dermis, such a condition has been called “ingrown hair.” We report a 30-year-old Chinese man, who was accustomed to pull or extrude the beard hairs, with 1-year history of slowly extending black linear eruption on his right chin. Cutaneous examination revealed a 4-cm long black linear lesion beneath the skin associated with edematous erythema around and folliculitis on both ends of the lesion. After treatment with topical mupirocin ointment, the erythema and folliculitis improved and 2 hairs of the beard with hair follicles were pulled out from the skin. Two weeks later, another similar black line about 1 cm in length in the skin presented on the prior lesional area, which was pulled out by a shallow incision of the skin and was also demonstrated as a beard hair with hair follicle. The patient was diagnosed as “ingrowing hair” with multiple recurrences. The lesions recovered after the beard hairs were pulled out. No recurrence occurred in a year of follow-up. We suggest that “ingrowing hair” is better than “ingrown hair” to describe such a condition. Pulling out the involved hair and correcting the bad practice are its optimal management strategies. PMID:27175694

  2. Total Mercury and Methylmercury Dynamics; stream export in an upland forested watershed in the Adirondack region of New York State

    NASA Astrophysics Data System (ADS)

    Carleton, W.; Vidon, P.; Mitchell, M. J.

    2012-12-01

    Although levels of mercury and acid rain deposition have greatly declined in recent years due to legislation controls on industry emissions, their legacy has had a lasting effect on the Adirondack region of New York State. This historical mercury deposition is of concern because of the high chance for methylmercury production and export to occur. The impact of forested uplands on methylmercury export remains poorly understood in relation to other ecosystems. Research indicates that sulfate dynamics play a large role in regulating the production of methylmercury in the presence of inorganic mercury; however the relationship between methylmercury production and nitrate availability at various times of the year is less understood, yet, hypothesized to potentially impact sulfate reduction and ultimately methylmercury production in a variety of ecosystems. In this study, mercury and water quality (including sulfate and nitrate) will be monitored in spring, summer and fall of 2012 at 7 locations in Arbutus Watershed, Adirondacks, NY. Proxies (UV absorbance, Fluorescence indices) for total mercury and methylmercury will be utilized to predict export. The main objectives of this research are to determine the relevance of forested uplands in methylmercury export, as well as gain further understanding of mercury dynamics and associated proxies in relation to nitrate and sulfate availability. Photo courtesy of the Adirondack Ecological Center

  3. Level of trace elements (copper, zinc, magnesium and selenium) and toxic elements (lead and mercury) in the hair and nail of children with autism.

    PubMed

    Lakshmi Priya, Malarveni Damodaran; Geetha, Arumugam

    2011-08-01

    Autism is a multi-factorial pathology observed in children with altered levels of essential and elevated levels of toxic elements. There are also studies reporting a decrease in nutritional trace elements in the hair and nail of autistic children with healthy controls; moreover, bioelements have been shown to play an important role in the central nervous system. Therefore, the purpose of the present study was to assess the levels of trace elements like copper (Cu), zinc (Zn), magnesium (Mg), and selenium (Se) and toxic elements like mercury (Hg), and lead (Pb) in the hair and nail samples of autistic children and to evaluate whether the level of these elements could be correlated with the severity of autism. The subjects of the study were 45 autistic children with different grades of severity (low (LFA), medium (MFA), and high (HFA) functioning autism) according to Childhood Autism Rating Scale, n = 15 children in each group and 50 healthy children (age and sex matched). The boys and girls ratio involved in this study was 4:1, and they were 4-12 years of age. The study observed a valid indication of Cu body burden in the autistic children. The children with different grades of autism showed high significance (p < 0.001) in the level of copper in their hair and nail samples when compared to healthy controls. The level of Cu in the autistic children could be correlated with their degree of severity (more the Cu burden severe is autism). The study showed a significant elevation (p < 0.001) in the levels of toxic metals Pb and Hg in both hair and nail samples of autistic children when compared to healthy control group. The elevation was much pronounced in LFA group subjects when compared among autistic groups MFA and HFA. The levels of trace elements Mg and Se were significantly decreased (p < 0.001) in autistic children when compared to control. The trace element Zn showed significant variation in both hair and nails of LFA group children when compared to control

  4. Prenatal Organochlorine and Methylmercury Exposure and Memory and Learning in School-Age Children in Communities Near the New Bedford Harbor Superfund Site, Massachusetts

    PubMed Central

    Orenstein, Sara T.C.; Thurston, Sally W.; Bellinger, David C.; Schwartz, Joel D.; Amarasiriwardena, Chitra J.; Altshul, Larisa M.

    2014-01-01

    Background: Polychlorinated biphenyls (PCBs), organochlorine pesticides, and methylmercury (MeHg) are environmentally persistent with adverse effects on neurodevelopment. However, especially among populations with commonly experienced low levels of exposure, research on neurodevelopmental effects of these toxicants has produced conflicting results. Objectives: We assessed the association of low-level prenatal exposure to these contaminants with memory and learning. Methods: We studied 393 children, born between 1993 and 1998 to mothers residing near a PCB-contaminated harbor in New Bedford, Massachusetts. Cord serum PCB, DDE (dichlorodiphenyldichloroethylene), and maternal peripartum hair mercury (Hg) levels were measured to estimate prenatal exposure. Memory and learning were assessed at 8 years of age (range, 7–11 years) using the Wide Range Assessment of Memory and Learning (WRAML), age-standardized to a mean ± SD of 100 ± 15. Associations with each WRAML index—Visual Memory, Verbal Memory, and Learning—were examined with multivariable linear regression, controlling for potential confounders. Results: Although cord serum PCB levels were low (sum of four PCBs: mean, 0.3 ng/g serum; range, 0.01–4.4), hair Hg levels were typical of the U.S. fish-eating population (mean, 0.6 μg/g; range, 0.3–5.1). In multivariable models, each microgram per gram increase in hair Hg was associated with, on average, decrements of –2.8 on Visual Memory (95% CI: –5.0, –0.6, p = 0.01), –2.2 on Learning (95% CI: –4.6, 0.2, p = 0.08), and –1.7 on Verbal Memory (95% CI: –3.9, 0.6, p = 0.14). There were no significant adverse associations of PCBs or DDE with WRAML indices. Conclusions: These results support an adverse relationship between low-level prenatal MeHg exposure and childhood memory and learning, particularly visual memory. Citation: Orenstein ST, Thurston SW, Bellinger DC, Schwartz JD, Amarasiriwardena CJ, Altshul LM, Korrick SA. 2014. Prenatal

  5. A 2,000-year record of mercury and ancient civilizations in seal hairs from King George Island, West Antarctica.

    PubMed

    Sun, Liguang; Yin, Xuebin; Liu, Xiaodong; Zhu, Renbin; Xie, Zhouqing; Wang, Yuhong

    2006-09-01

    The concentrations of total mercury (Hg(T)) and three bio-essential elements (phosphor, potassium, sodium) were analyzed in Antarctic seal hairs from a lake core spanning the past 2,000 years and collected from King George Island (63 degrees 23'S, 57 degrees 00'W), West Antarctica. The Hg(T) concentration shows a significant fluctuation while the levels of the three bio-essential elements remain almost constant. The rise and fall of the Hg(T) concentration in the seal hairs are found to be closely coincided with ancient activities of gold and silver mining using Hg-amalgamation process around the world, especially in the Southern Hemisphere. Briefly, Hg(T) levels are high during five episodes of extensive gold and silver mining activities--Rome Empire and China Han Dynasty (approximately 18-300 A.D.), Maya period and China Tang (750-900 A.D.), Incas civilization and Christian Kingdom (1200-1500 A.D.), New world (1650-1800 A.D.), and modern industry period (1840 A.D.-present); they are low during four time periods of reduced gold and silver mining activities--the China Han and Rome fall (since 300 A.D.), Maya fall and Wartime period in China (1050-1250 A.D.), Pizarro coming (ca. 1532 A.D.) and Independence War of South America (1800-1830 A.D.). Two profiles of Hg(T) in other two lake cores, one affected by seal excrements and the other by penguin droppings, from the same region are similar to the one in seal hairs. The Hg concentration profile in the seal hairs is significantly correlated with the one in a peat bog of Southern Chile near King George Island. Since Hg is existent mainly at the form of methyl-mercury in seal hairs, this correlation supports a relationship and link between atmospheric mercury concentration and methyl-mercury production. Comparing with samples from American and European continents, the Antarctic seal hairs provide an archive of total mercury concentration in surface seawater of the South Ocean less affected by regional human activities

  6. Determination of normal concentration levels of Cd, Cr, Cu, Hg, Pb, Se and Zn in hair of the child population in the Czech Republic.

    PubMed

    Benes, B; Sladká, J; Spevácková, V; Smid, J

    2003-12-01

    Knowledge of normal levels of concentrations of trace elements (Cd, Cr, Cu, Hg, Pb, Se and Zn) in the population serve, among others, in the designing of regulations of exposure limits and prevention of diseases caused by deficiency in essential trace elements. Concentrations of the named elements in the hair of children in the Czech population were determined by means of atomic absorption spectrometry. The samples of hair were collected during 1994- 2001 from 3,556 children (1,741 boys and 1,815 girls, average age 9.9 years). Mineralization in a microwave digestion system was used following a washing procedure. The accuracy of results was checked by means of the control materials CRM Human Hair GBW 07601. Values of concentrations of the trace elements in hair found for children were (in medians) 0.14 microg Cd.g(-1), 0.22 microg Cr.g(-1), 12 microg Cu.g(-1), 0.19 microg Hg.g(-1), 1.6 microg Pb.g(-1), 0.22 microg Se.g(-1) and 124 microg Zn.g(-1), respectively. Statistically significant differences between boys and girls were found for Cd, Cu and Zn. Concentrations of the elements under study correspond to the published values for the non-exposed population.

  7. Occurrence and levels of polybrominated diphenyl ethers (PBDEs) in house dust and hair samples from Northern Poland; an assessment of human exposure.

    PubMed

    Król, Sylwia; Namieśnik, Jacek; Zabiegała, Bożena

    2014-09-01

    Polybrominated diphenyl ethers (PBDEs) are among most ubiquitous compounds to be found in indoor environment and ingestion of household dust is considered an important route of exposure to PBDEs, especially in toddlers and young children. The present work reported concentration levels of PBDE congeners (PBDE-28, -47, -99, -100, -153, -154, -183 and -209) in hair and dust samples from selected households from Northern Poland. The concentrations of PBDEs in dust ranged from hair. PBDE-209 was reported the dominating congener. Two separated exposure scenarios (mean and 95th percentile) were used to provide a comprehensive overview of possible risks arising from ingestion of household dust. The estimated exposure to ∑PBDEs via ingestion of household dust varied from 21 to 92ngd(-1) in toddlers and from 3.7 to 20ngd(-1) in adults. By comparison of correlation between the concentrations of PBDEs in paired hair and dust samples the present work also investigated the possibility of use of hair for reflecting the actual exposure to PBDEs in humans. Finally the possible uncertainties associated with exposure assessment were investigated in the present study.

  8. Heat stress, divergent nutrition level, and late pregnancy in hair sheep: effects upon cotyledon development and litter weight at birth.

    PubMed

    Meza-Herrera, César Alberto; Vicente-Pérez, Arnulfo; Osorio-Marín, Yolanda; Girón-Gómez, Blenda Sinahí; Beltran-Calderon, Eira; Avendaño-Reyes, Leonel; Correa-Calderon, Abelardo; Macías-Cruz, Ulises

    2015-06-01

    The effect of two divergent nutritional levels during late pregnancy upon some physiological variables and the number (NC) and diameter (DC) of placental cotyledons along with litter weight at birth (LWB) on heat-stressed (42-45 °C) hair ewes was evaluated. Multiparous Katahdin x Pelibuey ewes (n = 24) at the onset of the 3/3 of pregnancy were randomly assigned to two treatments (n = 12): (1) non-nutritionally restricted (NNR) ewes, with free access to wheat straw plus 500 g/day of concentrate, and (2) nutritionally restricted (NR) ewes, receiving only wheat straw ad libitum. On days 100, 115, 130, and 145 of gestation, the body weight (BW), body condition score (BCS), rectal temperature (RT), respiration rate (RR) were registered in the afternoon (15:00) while the temperature-humidity index (THI) was calculated. At lambing, NC, DC, and LWB were also registered. Analyses considered a completely random design (CRD)-ANOVA with repeated measures across time, considering to litter size (LS) as covariable to reduce any possible influence of LS upon the response variables along experimental diets. BW and BCS were higher in NNR ewes at days 115, 130, and 145. Despite RT similarities (P < 0.05) between treatments, RR was greater (P < 0.01) in the NNR ewes, particularly towards the end of the experimental period. The observed THI averages confirmed severe heat stress conditions on ewes all day round across the experimental period, yet, NC, DC, and LWB favored (P < 0.05) to the NNR ewes. Despite that NNR ewes faced a significant heat stress based on the observed THI values, they consumed a diet with an increased energy-protein density, suggesting that the increased RR in the NNR group was exerted as a compensatory thermoregulation mechanism. Nutritional supplementation in hair ewes besides to an increase the energy body reserves (BW and BCS) also improved both the number and size of cotyledons, while generated an increased litter weight at birth.

  9. Quantifying Isoniazid Levels in Small Hair Samples: A Novel Method for Assessing Adherence during the Treatment of Latent and Active Tuberculosis

    PubMed Central

    Gerona, Roy; Wen, Anita; Chin, Aaron T.; Koss, Catherine A.; Bacchetti, Peter; Metcalfe, John; Gandhi, Monica

    2016-01-01

    Background Tuberculosis (TB) is the leading cause of death from an infectious pathogen worldwide and the most prevalent opportunistic infection in people living with HIV. Isoniazid preventive therapy (IPT) reduces the incidence of active TB and reduces morbidity and mortality in HIV-infected patients independently of antiretroviral therapy. However, treatment of latent or active TB is lengthy and inter-patient variability in pharmacokinetics and adherence common. Current methods of assessing adherence to TB treatment using drug levels in plasma or urine assess short-term exposure and pose logistical challenges. Drug concentrations in hair assess long-term exposure and have demonstrated pharmacodynamic relevance in HIV. Methods A large hair sample from a patient with active TB was obtained for assay development. Methods to pulverize hair and extract isoniazid were optimized and then the drug detected by liquid chromatography/ tandem mass spectrometry (LC/MS-MS). The method was validated for specificity, accuracy, precision, recovery, linearity and stability to establish the assay’s suitability for therapeutic drug monitoring (TDM). Hair samples from patients on directly-observe isoniazid-based latent or active TB therapy from the San Francisco Department of Public Health TB clinic were then tested. Results Our LC/MS-MS-based assay detected isoniazid in quantities as low as 0.02ng/mg using 10–25 strands hair. Concentrations in spiked samples demonstrated linearity from 0.05–50ng/mg. Assay precision and accuracy for spiked quality-control samples were high, with an overall recovery rate of 79.5%. In 18 patients with latent or active TB on treatment, isoniazid was detected across a wide linear dynamic range. Conclusions An LC-MS/MS-based assay to quantify isoniazid levels in hair with performance characteristics suitable for TDM was developed and validated. Hair concentrations of isoniazid assess long-term exposure and may be useful for monitoring adherence to

  10. Organotropism of methylmercury in fish of the southeastern of Brazil.

    PubMed

    Azevedo, L S; Almeida, M G; Bastos, W R; Suzuki, M S; Recktenvald, M C N N; Bastos, M T S; Vergílio, C S; de Souza, C M M

    2017-10-01

    This is one of the first studies to evaluate the effect of biometric variables (total length and weight), diet, and abiotic matrices (sediment and water column) on the bioaccumulation of methylmercury in tissues (muscle, liver, and gills) of four fish (two carnivore-invertivores, Pimelodus fur and Pachyurus adspersus; one carnivore-piscivore, Oligosarcus hepsetus; and one omnivore, Pimelodella lateristriga) in the lower section of a river in southeastern Brazil. Samples of fish (n = 120), water (n = 5) and sediment (n = 5) were collected at five sites characterized by pollution with mercury due to the use of organomercury fungicides and stream bed gold mining, commonly carried out in that section of the river in the 1980s. The results show that biometric variables are strongly correlated with methylmercury levels in muscle (r = 0.61, p < 0.0005) of P. fur. As a rule, concentrations of total mercury and methylmercury did not vary considerably between the organs of the species of different food habits, because of the environmental conditions in the study area. Despite the low concentrations of mercury in sediments (<0.05 mg kg(-1) wet. wt), this compartment is a representative source of this pollutant for the organisms investigated, due to the close contact these animals keep with it in view of the low water columns in that section of the river. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Prenatal organochlorine and methylmercury exposure and memory and learning in school-age children in communities near the New Bedford Harbor Superfund site, Massachusetts.

    PubMed

    Orenstein, Sara T C; Thurston, Sally W; Bellinger, David C; Schwartz, Joel D; Amarasiriwardena, Chitra J; Altshul, Larisa M; Korrick, Susan A

    2014-11-01

    Polychlorinated biphenyls (PCBs), organochlorine pesticides, and methylmercury (MeHg) are environmentally persistent with adverse effects on neurodevelopment. However, especially among populations with commonly experienced low levels of exposure, research on neurodevelopmental effects of these toxicants has produced conflicting results. We assessed the association of low-level prenatal exposure to these contaminants with memory and learning. We studied 393 children, born between 1993 and 1998 to mothers residing near a PCB-contaminated harbor in New Bedford, Massachusetts. Cord serum PCB, DDE (dichlorodiphenyldichloroethylene), and maternal peripartum hair mercury (Hg) levels were measured to estimate prenatal exposure. Memory and learning were assessed at 8 years of age (range, 7-11 years) using the Wide Range Assessment of Memory and Learning (WRAML), age-standardized to a mean ± SD of 100 ± 15. Associations with each WRAML index-Visual Memory, Verbal Memory, and Learning-were examined with multivariable linear regression, controlling for potential confounders. Although cord serum PCB levels were low (sum of four PCBs: mean, 0.3 ng/g serum; range, 0.01-4.4), hair Hg levels were typical of the U.S. fish-eating population (mean, 0.6 μg/g; range, 0.3-5.1). In multivariable models, each microgram per gram increase in hair Hg was associated with, on average, decrements of -2.8 on Visual Memory (95% CI: -5.0, -0.6, p = 0.01), -2.2 on Learning (95% CI: -4.6, 0.2, p = 0.08), and -1.7 on Verbal Memory (95% CI: -3.9, 0.6, p = 0.14). There were no significant adverse associations of PCBs or DDE with WRAML indices. These results support an adverse relationship between low-level prenatal MeHg exposure and childhood memory and learning, particularly visual memory.

  12. IRIS Summary and Supporting Documents for Methylmercury

    EPA Science Inventory

    In January 2001, U.S. EPA finalized the guidance for methylmercury in the water quality criteria for states and authorized tribes. The links below take you to the best resources for this guidance.

  13. IRIS Summary and Supporting Documents for Methylmercury

    EPA Science Inventory

    In January 2001, U.S. EPA finalized the guidance for methylmercury in the water quality criteria for states and authorized tribes. The links below take you to the best resources for this guidance.

  14. Effects of fixed orthodontic treatment using conventional (two-piece) versus metal injection moulding brackets on hair nickel and chromium levels: a double-blind randomized clinical trial.

    PubMed

    Khaneh Masjedi, Mashallah; Haghighat Jahromi, Nima; Niknam, Ozra; Hormozi, Elham; Rakhshan, Vahid

    2017-02-01

    Although nickel and chromium are known as allergen and cytotoxic orthodontic metals, very few and controversial studies have assessed the effect of orthodontic treatment on their systemic levels especially those reflected by their best biomarker of exposure, hair. Additionally, metal injection moulding (MIM) brackets are not studied, and there is no study on systemic ion changes following their usage. In this double-blind randomized clinical trial, scalp hair samples of 24 female and 22 male fixed orthodontic patients [as two groups of conventional (two-piece) versus MIM brackets, n = 23×2] were collected before treatment and 6 months later. Randomization was carried out using a computer-generated random number table. The patients, laboratory expert, and author responsible for analyses were blinded of the bracket allocations. Hair nickel and chromium levels were measured using atomic absorption spectrophotometry. The effects of treatment, bracket types, gender, and age on hair ions were analysed statistically (α = 0.05, β ≤ 0.02). In both groups combined (n = 46), nickel increased from 0.1600±0.0890 µg/g dry hair mass (pre-treatment) to 0.3199±0.1706 (6th month). Chromium increased from 0.1657±0.0884 to 0.3066±0.1362 µg/g. Both of these increases were significant (paired t-test, P = 0.0000). Bracket types, age, and gender had no significant influence on ion levels (P > 0.05). ANCOVA indicated different patterns of chromium increases in different genders (P = 0.033) and ages (P = 0.056). Sample size determination should have accounted for the grouping as well. Hair nickel and chromium levels might increase about 185-200% after 6 months. They might not be affected by bracket types. Gender and age might not influence the baseline or 6th-month levels of both metals. Gender might however interact with orthodontic treatment, only in the case of chromium. The research is registered offline (thesis) and online (IR.AJUMS.REC.1394.516). The protocol was pre

  15. Relationship between localization of gold mining areas and hair mercury levels in people from Bolivar, north of Colombia.

    PubMed

    Olivero-Verbel, Jesús; Caballero-Gallardo, Karina; Marrugo Negrete, Jose; Negrete-Marrugo, José

    2011-12-01

    Mercury (Hg) is a heavy metal that, once in the environment, is bioaccumulated and biomagnified through food chain impacting ecosystems. The aim of this study was to evaluate total Hg (T-Hg) concentrations in individuals along Cauca and Magdalena Rivers in Colombia, where most gold mining activities take place. A total of 1,328 hair samples were collected and analyzed for T-Hg using atomic absorption spectroscopy. T-Hg concentrations ranged from 0.01 to 20.14 μg/g. Greatest levels were detected in La Raya (5.27 ± 0.32 μg/g), Achi (2.44 ± 0.22 μg/g), and Montecristo (2.20 ± 0.20 μg/g), places that are located near gold mines. Concentrations decreased with the distance from main mining areas. Only 0.75% of the individuals had T-Hg levels above 10 μg/g. Men had significantly higher T-Hg levels than women, and correlation analysis revealed moderately weak but significant relationships between T-Hg and weight (R = 0.111, P < 0.001), stature (R = 0.111, P < 0.001), and age (R = 0.073, P = 0.007). However, T-Hg concentrations did not vary according to fish consumption frequency. Subjective health survey showed no Hg-related signs or symptoms within studied sample. However, studies are necessary to detect neurological damage linked to the metal. Changing technologies to Hg-free mining, monitoring, and educational programs are necessary to protect health of people living near Colombian rivers.

  16. Effects of methylmercury on operant behavior

    SciTech Connect

    Laties, V.G.; Evans, H.L.

    1982-01-01

    Experimental observations on methylmercury's effects on the behavior of pigeons are used to illustrate how operant techniques can be used to investigate long-lasting consequences of a toxic insult. The methylmercury is shown to disturb the ability of pigeons to discriminate the amount of behavior that they have emitted: they become less accurate in pecking the specific number of times needed to earn them food.

  17. Low level light-minoxidil 5% combination versus either therapeutic modality alone in management of female patterned hair loss: A randomized controlled study.

    PubMed

    Esmat, Samia M; Hegazy, Rehab A; Gawdat, Heba I; Abdel Hay, Rania M; Allam, Riham S; El Naggar, Rofaida; Moneib, Hoda

    2017-05-10

    Female pattern hair loss (FPHL) is the most common form of hair loss in women. Nevertheless, its management represents a real challenge. Among the FDA approved therapeutic modalities for FPHL are topical minoxidil and more recently low-level light therapy (LLLT). Assess the efficacy and safety of LLLT in comparison to topical minoxidil 5% and to a combination of both therapies in the treatment of FPHL. This study included 45 female patients with proven FPHL. They were randomly divided into three equal groups, where group (i) patients were instructed to apply topical minoxidil 5% twice daily, group (ii) patients received LLLT using the helmet iGrow® device for 25 minutes 3 days weekly, and group (iii) patients received a combination of both topical minoxidil 5% twice daily and LLLT for 25 minutes 3 days weekly for 4 months (study duration). Evaluation was done according to clinical, dermoscopic (folliscopic), and ultrasound bio-microscopic (UBM) parameters. Patient satisfaction and side effects were reported. The efficacy and safety of both topical minoxidil and LLLT were highlighted with comparable results in all parameters. The combination group (iii) occupied the top position regarding Ludwig classification and patient satisfaction. UBM and dermoscopic findings showed significant increase in the number of regrowing hair follicles at 4 months in all groups, whereas only UBM showed such significant increase at 2 months in the combination group (iii). A non-significant increase in the hair diameter was also documented in the three groups. LLLT is an effective and safe tool with comparable results to minoxidil 5% in the treatment of FPHL. Owing to the significantly better results of combination therapy, its usage is recommended to hasten hair regrowth. Lasers Surg. Med. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  18. Mercury Levels in Human Hair and Farmed Fish near Artisanal and Small-Scale Gold Mining Communities in the Madre de Dios River Basin, Peru

    PubMed Central

    Langeland, Aubrey L.; Hardin, Rebecca D.; Neitzel, Richard L.

    2017-01-01

    Artisanal and small-scale gold mining (ASGM) has been an important source of income for communities in the Madre de Dios River Basin in Peru for hundreds of years. However, in recent decades, the scale of ASGM activities in the region has increased dramatically, and exposures to a variety of occupational and environmental hazards related to ASGM, including mercury, are becoming more widespread. The aims of our study were to: (1) examine patterns in the total hair mercury level of human participants in several communities in the region and compare these results to the 2.2 µg/g total hair mercury level equivalent to the World Health Organization (WHO) Expert Committee of Food Additives (JECFA)’s Provisional Tolerable Weekly Intake (PTWI); and (2), to measure the mercury levels of paco (Piaractus brachypomus) fish raised in local aquaculture ponds, in order to compare these levels to the EPA Fish Tissue Residue Criterion of 0.3 µg Hg/g fish (wet weight). We collected hair samples from 80 participants in four communities (one control and three where ASGM activities occurred) in the region, and collected 111 samples from fish raised in 24 local aquaculture farms. We then analyzed the samples for total mercury. Total mercury levels in hair were statistically significantly higher in the mining communities than in the control community, and increased with increasing geodesic distance from the Madre de Dios headwaters, did not differ by sex, and frequently exceeded the reference level. Regression analyses indicated that higher hair mercury levels were associated with residence in ASGM communities. The analysis of paco fish samples found no samples that exceeded the EPA tissue residue criterion. Collectively, these results align with other recent studies showing that ASGM activities are associated with elevated human mercury exposure. The fish farmed through the relatively new process of aquaculture in ASGM areas appeared to have little potential to contribute to human

  19. Mercury Levels in Human Hair and Farmed Fish near Artisanal and Small-Scale Gold Mining Communities in the Madre de Dios River Basin, Peru.

    PubMed

    Langeland, Aubrey L; Hardin, Rebecca D; Neitzel, Richard L

    2017-03-14

    Artisanal and small-scale gold mining (ASGM) has been an important source of income for communities in the Madre de Dios River Basin in Peru for hundreds of years. However, in recent decades, the scale of ASGM activities in the region has increased dramatically, and exposures to a variety of occupational and environmental hazards related to ASGM, including mercury, are becoming more widespread. The aims of our study were to: (1) examine patterns in the total hair mercury level of human participants in several communities in the region and compare these results to the 2.2 µg/g total hair mercury level equivalent to the World Health Organization (WHO) Expert Committee of Food Additives (JECFA)'s Provisional Tolerable Weekly Intake (PTWI); and (2), to measure the mercury levels of paco (Piaractus brachypomus) fish raised in local aquaculture ponds, in order to compare these levels to the EPA Fish Tissue Residue Criterion of 0.3 µg Hg/g fish (wet weight). We collected hair samples from 80 participants in four communities (one control and three where ASGM activities occurred) in the region, and collected 111 samples from fish raised in 24 local aquaculture farms. We then analyzed the samples for total mercury. Total mercury levels in hair were statistically significantly higher in the mining communities than in the control community, and increased with increasing geodesic distance from the Madre de Dios headwaters, did not differ by sex, and frequently exceeded the reference level. Regression analyses indicated that higher hair mercury levels were associated with residence in ASGM communities. The analysis of paco fish samples found no samples that exceeded the EPA tissue residue criterion. Collectively, these results align with other recent studies showing that ASGM activities are associated with elevated human mercury exposure. The fish farmed through the relatively new process of aquaculture in ASGM areas appeared to have little potential to contribute to human

  20. Ingrown Hair

    MedlinePlus

    ... needed to determine whether a single- or multiple-blade razor is best for preventing ingrown hair. See ... to see what works for you. Rinse the blade after each stroke. Rinse your skin and apply ...

  1. Hair Loss

    MedlinePlus

    ... of hair loss have found patients’ self-esteem, body image and self-confidence to be negatively affected. 1-2 Known psychosocial complications include depression, low self-esteem, altered self-image, and less frequent and enjoyable ...

  2. Dry hair

    MedlinePlus

    ... St Louis, MO: Elsevier Mosby; 2015:chap 8. Marks JG, Miller JJ. Hair disorders. In: Marks JG, Miller JJ, eds. Lookingbill and Marks' Principles of Dermatology . 5th ed. Philadelphia, PA: Elsevier ...

  3. Hair Loss

    MedlinePlus

    ... face and hands, and rapid heart rate (tachycardia). Finasteride (Propecia). This prescription drug is available only to ... taken daily in pill form. Many men taking finasteride experience a slowing of hair loss, and some ...

  4. Serum Vitamin D3 Levels and Diffuse Hair Fall among the Student Population in South India: A Case-Control Study.

    PubMed

    Nayak, Kashinath; Garg, Aaina; Mithra, Prasanna; Manjrekar, Poornima

    2016-01-01

    Hair fall is a common problem faced by many younger people, which has variety of risk factors. Vitamin D3 has emerged as a molecule with key role to play in various disorders. This study was done to assess its role in diffuse hair fall among student population. This was a case-control study including young adults presenting with complaints of hair fall (>100 a day) as cases, with age-matched healthy controls. Vitamin D3 levels were measured in all the patients. Data analysis was done using Statistical Package for Social Sciences version 11.5 software and significance was tested using Chi-square test and binary logistic regression analysis. Atotal of 44 participants were enrolled; 22 in each arm. The mean age of the study population was 20.89 years (standard deviation: 1.49). The median value of Vitamin D was 6.80 (interquartile range - 5.350-16.63) for the study population. Overall, 81.8% cases had Vitamin D deficiency compared to 45.5% of controls and this difference was statistically significant (P = 0.007). Furthermore, females had a statistically significant difference in Vitamin D levels between cases and controls. Higher level of full sleeve cloth usage, sunscreen lotion application, and lesser sun exposures were seen among cases although these differences were not statistically significant. The levels of Vitamin D3 were not significantly different among Indians, nonresident Indians, and foreigners. None of the cases had normal Vitamin D values whereas 4.5% controls fell in the normal category. Female patients with diffuse hair fall were found to have significantly low Vitamin D3 levels among student population.

  5. Economic implications of mercury exposure in the context of the global mercury treaty: Hair mercury levels and estimated lost economic productivity in selected developing countries.

    PubMed

    Trasande, Leonardo; DiGangi, Joseph; Evers, David C; Petrlik, Jindrich; Buck, David G; Šamánek, Jan; Beeler, Bjorn; Turnquist, Madeline A; Regan, Kevin

    2016-12-01

    Several developing countries have limited or no information about exposures near anthropogenic mercury sources and no studies have quantified costs of mercury pollution or economic benefits to mercury pollution prevention in these countries. In this study, we present data on mercury concentrations in human hair from subpopulations in developing countries most likely to benefit from the implementation of the Minamata Convention on Mercury. These data are then used to estimate economic costs of mercury exposure in these communities. Hair samples were collected from sites located in 15 countries. We used a linear dose-response relationship that previously identified a 0.18 IQ point decrement per part per million (ppm) increase in hair mercury, and modeled a base case scenario assuming a reference level of 1 ppm, and a second scenario assuming no reference level. We then estimated the corresponding increases in intellectual disability and lost Disability-Adjusted Life Years (DALY). A total of 236 participants provided hair samples for analysis, with an estimated population at risk of mercury exposure near the 15 sites of 11,302,582. Average mercury levels were in the range of 0.48 ppm-4.60 ppm, and 61% of all participants had hair mercury concentrations greater than 1 ppm, the level that approximately corresponds to the USA EPA reference dose. An additional 1310 cases of intellectual disability attributable to mercury exposure were identified annually (4110 assuming no reference level), resulting in 16,501 lost DALYs (51,809 assuming no reference level). A total of $77.4 million in lost economic productivity was estimated assuming a 1 ppm reference level and $130 million if no reference level was used. We conclude that significant mercury exposures occur in developing and transition country communities near sources named in the Minamata Convention, and our estimates suggest that a large economic burden could be avoided by timely implementation of measures to

  6. Hair Dye and Hair Relaxers

    MedlinePlus

    ... Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products For Consumers Home For Consumers Consumer ... Resources for You Hair Products Bad Reaction to Cosmetics? Tell FDA Cosmetics Tips Are Some Cosmetics Promising ...

  7. A biochemical study on the level of proteins and their percentage of nitration in the hair and nail of autistic children.

    PubMed

    Lakshmi Priya, Malarveni Damodaran; Geetha, Arumugam

    2011-05-12

    Autism is a complex disorder which is heterogeneous in nature with varying degrees of severity for which no specific biological marker has been identified. Several studies are focused on the hair and nail protein pattern as a means to identify specific markers for the diagnosis of many childhood disorders like mental retardation, dyslexia, trichorrhexis nodosa, trichothiodystrophy, etc. The present study is one such approach in investigating the electrophoretic pattern of proteins in hard keratins and their percentage of nitration since nitric oxide production and nitration of tyrosine residues in proteins of autistic children are the emerging topic of research. We extracted and quantified the proteins from hair and nail samples of autistic children with different grades of severity, [low functioning autism (LFA), medium functioning autism (MFA), and high functioning autism (HFA)] and also from age- and sex-matched normal children. Protein pattern was evaluated by one-dimensional SDS-PAGE and the separated proteins were made to cross react with anti-nitro tyrosine antibody by Western blot analysis. Blood levels of TBARS, NO, GSH, vitamins A and C, SOD and GPx were also determined. In the autistic groups, decreased concentration of protein in both hair and nail samples was observed. The SDS-PAGE analysis revealed that there was a significant decrease in both high and low sulfur proteins in the hair and nail extracts of autistic children and the Western blot analysis showed increased percentage of nitration of low sulfur proteins in autistic children when compared with normal children. Decreased levels of enzymatic and non-enzymatic antioxidants and increased concentration of TBARS and NO were also observed in the blood of autistic children. The LFA group showed more significant alteration (p<0.001) in the concentration of proteins (in hair and nail) and percentage of nitration when compared with HFA and controls. Lower protein content and higher percentage of

  8. Human exposure to methylmercury through rice intake in mercury mining areas, Guizhou province, China.

    PubMed

    Feng, Xinbin; Li, Ping; Qiu, Guangle; Wang, Shaofeng; Li, Guanghui; Shang, Lihai; Meng, Bo; Jiang, Hongmei; Bai, Weiyang; Li, Zhonggen; Fu, Xuewu

    2008-01-01

    The toxicity of methylmercury (Me-Hg) has caused widespread public human concern as a result of several widely publicized disasters. Me-Hg is highly toxic, and the nervous system is its principal target tissue for humans. Although the general population is primarily exposed to Me-Hg through contaminated fish and marine mammals, in Hg mining areas a long history of mining activities can produce serious Hg pollution to the local environment In a study of 98 persons from the Wanshan Hg mining area, hair Me-Hg levels indicated Me-Hg exposure. Rice, the staple food of the local inhabitants also showed high total Hg (T-Hg) and Me-Hg levels. The geometric mean concentration of T-Hg and mean concentration of Me-Hg in rice samples collected from 3 villages in Wanshan Hg mining area were 36.2 (ranging from 4.9 to 214.7), and 8.5 (ranging from 1.9 to 27.6) microg/kg, respectively, which were significantly elevated compared to the rice samples collected from a reference area, where the mean T-Hg and Me-Hg concentrations were 7.0 (3.2-15.1) and 2.5 (0.8-4.3) microg/kg, respectively. Pork meat, vegetable, and drinking water samples collected in Wanshan Hg mining area contained highly elevated T-Hg, but very low levels of Me-Hg. The relationships between the estimated rice Me-Hg intake and hair Me-Hg levels (r = 0.65, p < 0.001) confirmed rice with high Me-Hg levels indeed was the main route of Me-Hg exposure for the local residents in the Wanshan Hg mining area. From our study, we can conclude that the main human exposure to Me-Hg via food consumption is not restricted to fish, but in some cases in mining areas of China to frequent rice meals.

  9. Biomarkers of Methylmercury Exposure Immunotoxicity among Fish Consumers in Amazonian Brazil

    PubMed Central

    Fillion, Myriam; Barbosa, Fernando; Shirley, Devon L.; Chine, Chiameka; Lemire, Melanie; Mergler, Donna; Silbergeld, Ellen K.

    2011-01-01

    Background: Mercury (Hg) is a ubiquitous environmental contaminant with neurodevelopmental and immune system effects. An informative biomarker of Hg-induced immunotoxicity could aid studies on the potential contribution to immune-related health effects. Objectives: Our objectives were to test the hypothesis that methylmercury (MeHg) exposures affect levels of serum biomarkers and to examine interactions between Hg and selenium (Se) in terms of these responses. Methods: This cross-sectional epidemiological study assessed adults living along the Tapajós River, a system long affected by MeHg. We measured antinuclear (ANA) and antinucleolar (ANoA) autoantibody levels and eight cytokines in serum samples (n = 232). Total Hg (including MeHg) and Se were measured in blood, plasma, hair, and urine. Results: The median (range) total Hg concentrations were 14.1 μg/g (1.1–62.4), 53.5 μg/L (4.3–288.9), 8.8 μg/L (0.2–40), and 3.0 μg/L (0.2–16.1) for hair, blood, plasma, and urine, respectively. Elevated titers of ANA (but not ANoA) were positively associated with MeHg exposure (log-transformed, for blood and plasma), unadjusted [odds ratio (OR) = 2.6; 95% confidence interval (CI): 1.1, 6.2] and adjusted for sex and age (OR = 2.9; 95% CI: 1.1, 7.5). Proinflammatory [interleukin (IL)-6 and interferon (IFN)-©], anti-inflammatory (IL-4), and IL-17 cytokine levels were increased with MeHg exposure; however, in the subset of the population with elevated ANA, proinflammatory IL-1®, IL-6, IFN-©, and tumor necrosis factor (TNF)-〈 and anti-inflammatory (IL-4) cytokine levels were decreased with MeHg exposure. Although Se status was associated with MeHg level (correlation coefficient = 0.86; 95% CI: 0.29, 1.43), Se status was not associated with any changes in ANA and did not modify associations between Hg and ANA titers. Conclusions: MeHg exposure was associated with an increased ANA and changes in serum cytokine profile. Moreover, alterations in serum cytokine profiles

  10. Comparison of lead and zinc levels in the hair of pupils from four towns in the Kumasi Municipal Area of Ghana

    SciTech Connect

    Golow, A.A.; Kwaansa-Ansah, E.E. )

    1994-09-01

    When metals enter the body of living organisms, even in trace amounts, they may not be metabolized and may accumulate if not excreted. During the process of accumulation they may attain levels which may be toxic to the organism. In the body some of the metals may accumulate in special organs or tissues where they may effect changes. Others may remain in the general body fluid and influence all enzyme systems. Some of these influences may be beneficial and others detrimental. Hence it is important to learn of metals which enter the body so that any undue increases in their amounts may be avoided. The bone is usually the site for the accumulation of metals and may serve as a store house and contain a library of the record of what have entered the body of the organism. However human bone is not easy to sample. The hair, though lesser known as site for accumulation of metals, it accumulates more lead per unit weight than any tissue in the body including even body fluids such as blood and urine. The human hair, depending upon the belief, culture and scientific awareness of the people may be easy or difficult to sample. In many instances the hair of humans especially that of males is cut and disposed off as waste materials. Apparently such unwanted hair could be analyzed and studied to learn of both external and internal exposure of the population to contamination and pollution. A knowledge of levels of metals in non-occupationally exposed citizens as compared with those in occupationally exposed people may serve as a guide in protecting the whole population against industrial pollution and its associated diseases. The report presented here is part of a project designed to find the levels of metals in the hair of the population in general before looking at the levels which may be obtained in some mine workers or occupationally exposed, in the country. Such levels may serve as natural background levels for future reference. 10 refs., 3 figs., 2 tabs.

  11. Assessing and managing methylmercury risks associated with power plant mercury emissions in the United States.

    PubMed

    Charnley, Gail

    2006-03-09

    Until the Clean Air Mercury Rule was signed in March 2005, coal-fired electric utilities were the only remaining, unregulated major source of industrial mercury emissions in the United States. Proponents of coal-burning power plants assert that methylmercury is not a hazard at the current environmental levels, that current technologies for limiting emissions are unreliable, and that reducing mercury emissions from power plants in the United States will have little impact on environmental levels. Opponents of coal-burning plants assert that current methylmercury exposures from fish are damaging to the developing nervous system of infants, children, and the fetus; that current technology can significantly limit emissions; and that reducing emissions will reduce exposure and risk. One concern is that local mercury emissions from power plants may contribute to higher local exposure levels, or "hot spots." The impact of the Mercury Rule on potential hot spots is uncertain due to the highly site-specific nature of the relationship between plant emissions and local fish methylmercury levels. The impact on the primary source of exposure in the United States, ocean fish, is likely to be negligible due to the contribution of natural sources and industrial sources outside the United States. Another debate centers on the toxic potency of methylmercury, with the scientific basis of the US Environmental Protection Agency's (EPA's) recommended exposure limit questioned by some and defended by others. It is likely that the EPA's exposure limit may be appropriate for combined exposure to methylmercury and polychlorinated biphenyls (PCBs), but may be lower than the available data suggest is necessary to protect children from methylmercury alone. Mercury emissions from power plants are a global problem. Without a global approach to developing and implementing clean coal technologies, limiting US power plant emissions alone will have little impact.

  12. Hair Treatments and Pregnancy

    MedlinePlus

    ... dyes. Common chemicals in hair dyes include hydrogen peroxide, ammonia, and alcohols. Hair curling or permanent wave ... thioglycolate and ammonia. Hair bleaching chemicals include hydrogen peroxide. Hair straighteners (relaxers) use a variety of chemicals. ...

  13. Hair Treatments and Pregnancy

    MedlinePlus

    ... dyes. Common chemicals in hair dyes include hydrogen peroxide, ammonia, and alcohols. Hair curling or permanent wave ... thioglycolate and ammonia. Hair bleaching chemicals include hydrogen peroxide. Hair straighteners (relaxers) use a variety of chemicals. ...

  14. Long term neurocognitive impact of low dose prenatal methylmercury exposure in Hong Kong.

    PubMed

    Lam, Hugh Simon; Kwok, Ka Ming; Chan, Peggy Hiu Ying; So, Hung Kwan; Li, Albert Martin; Ng, Pak Cheung; Fok, Tai Fai

    2013-04-01

    International studies suggest that low dose prenatal methylmercury exposure (>29 nmol/L) has long-term adverse neurocognitive effects. There is evidence that the majority of children in Hong Kong exceed this level as a result of high fish consumption of mothers during pregnancy. To study whether there are any associations between low-dose prenatal methylmercury exposure and neurocognitive outcomes in Hong Kong children. All 1057 children from the original birth cohort were eligible for entry into the study, except children with conditions that would affect neurocognitive development, but were unrelated to methylmercury exposure. Subjects were assessed by a wide panel of tests covering a broad range of neurocognitive functions: Hong Kong Wechsler Intelligence Scale for Children (HK-WISC), Hong Kong List Learning Test (HKLLT), Tests of Everyday Attention for Children (TEACH), Boston Naming Test, and Grooved Pegboard Test. 608 subjects were recruited (median age 8.2 years, IQR 7.3, 8.8; 53.9% boys). After correction by confounders including child age and sex, multivariate analysis showed that cord blood mercury concentration was significantly associated with three subtests: Picture Arrangement of HK-WISC (coefficient -0.944, P=0.049) and Short and Long Delay Recall Difference of the HKLLT (coefficient -1.087, P=0.007 and coefficient -1.161, P=0.005, respectively), i.e., performance worsened with increasing prenatal methylmercury exposure in these subtests. Small, but statistically significant adverse associations between prenatal methylmercury exposure and long-term neurocognitive effects (a visual sequencing task and retention ability of verbal memory) were found in our study. These effects are compatible with findings of studies with higher prenatal methylmercury exposure levels and suggest that safe strategies to further reduce exposure levels in Hong Kong are desirable. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Hair follicle growth controls.

    PubMed

    Stenn, K S; Combates, N J; Eilertsen, K J; Gordon, J S; Pardinas, J R; Parimoo, S; Prouty, S M

    1996-10-01

    Research in hair biology has embarked in the pursuit for molecules that control hair growth. Many molecules already have been associated with the controls of hair patterning, hair maturation, and hair cycling and differentiation. Knowing how these molecules work gives us the tools for understanding and treating patients with hair disorders.

  16. Form of Dietary Methylmercury does not Affect Total Mercury Accumulation in the Tissues of Zebra Finch.

    PubMed

    Varian-Ramos, Claire W; Whitney, Margaret; Rice, Gary W; Cristol, Daniel A

    2017-07-01

    Exposure to mercury in humans, other mammals, and birds is primarily dietary, with mercury in the methylated form and bound to cysteine in the tissues of prey items. Yet dosing studies are generally carried out using methylmercury chloride. Here we tested whether the accumulation of total mercury in zebra finch blood, egg, muscle, liver, kidney or brain differed depending on whether dietary mercury was complexed with chloride or cysteine. We found no effect of form of mercury on tissue accumulation. Some previous studies have found lower accumulation of mercury in tissues of animals fed complexed mercury. Much remains to be understood about what happens to ingested mercury once it enters the intestines, but our results suggest that dietary studies using methylmercury chloride in birds will produce similar tissue accumulation levels to those using methylmercury cysteine.

  17. Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals

    SciTech Connect

    Goodrich, Jaclyn M.; Wang, Yi; Gillespie, Brenda; Werner, Robert; Franzblau, Alfred; Basu, Niladri

    2011-12-15

    Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione s-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n = 515), and total mercury content was measured. Average urine (1.06 {+-} 1.24 ug/L) and hair mercury levels (0.49 {+-} 0.63 ug/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5 Prime ), or both (SEPP1 3 Prime UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). -- Highlights: Black-Right-Pointing-Pointer We explore the influence of 15 polymorphisms on urine and hair Hg levels. Black-Right-Pointing-Pointer Urine and hair Hg levels in dental professionals were similar to the US population. Black-Right-Pointing-Pointer GSTT1 and SEPP1 polymorphisms associated with urine Hg levels. Black

  18. Hierarchical capillary adhesion of microcantilevers or hairs

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Lin; Feng, Xi-Qiao; Xia, Re; Zhao, Hong-Ping

    2007-09-01

    As a result of capillary forces, animal hairs, carbon nanotubes or nanowires of a periodically or randomly distributed array often assemble into hierarchical structures. In this paper, the energy method is adopted to analyse the capillary adhesion of microsized hairs, which are modelled as clamped microcantilevers wetted by liquids. The critical conditions for capillary adhesion of two hairs, three hairs or two bundles of hairs are derived in terms of Young's contact angle, elastic modulus and geometric sizes of the beams. Then, the hierarchical capillary adhesion of hairs is addressed. It is found that for multiple hairs or microcantilevers, the system tends to take a hierarchical structure as a result of the minimization of the total potential energy of the system. The level number of structural hierarchy increases with the increase in the number of hairs if they are sufficiently long. Additionally, we performed experiments to verify our theoretical solutions for the adhesion of microbeams.

  19. Potential sources of methylmercury in tree foliage.

    PubMed

    Tabatchnick, Melissa D; Nogaro, Géraldine; Hammerschmidt, Chad R

    2012-01-01

    Litterfall is a major source of mercury (Hg) and toxic methylmercury (MeHg) to forest soils and influences exposures of wildlife in terrestrial and aquatic ecosystems. However, the origin of MeHg associated with tree foliage is largely unknown. We tested the hypothesis that leaf MeHg is influenced by root uptake and thereby related to MeHg levels in soils. Concentrations of MeHg and total Hg in deciduous and coniferous foliage were unrelated to those in soil at 30 urban and rural forested locations in southwest Ohio. In contrast, tree genera and trunk diameter were significant variables influencing Hg in leaves. The fraction of total Hg as MeHg averaged 0.4% and did not differ among tree genera. Given that uptake of atmospheric Hg(0) appears to be the dominant source of total Hg in foliage, we infer that MeHg is formed by in vivo transformation of Hg in proportion to the amount accumulated. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Hair colouring, permanent styling and hair structure.

    PubMed

    Harrison, S; Sinclair, R

    2003-07-01

    Hair is an important component of body image and has immense psychological importance for both men and women. Women, in particular, over the ages have modified their appearance through changing their hair colour or style. Hair can be straight, wavy or curly, blonde, black, brown or red. These natural variations are an important part of our identity that can be manipulated according to the dictates of fashion, culture or society. Different types of hair have varying affinity for the different colouring and waving methods. Damaged hair also has a different affinity for hair products than normal healthy hair. The hair shaft is remarkably strong and resistant to the extremes of nature. Hair cosmetics are widely available and manipulate the structural properties of hair. Whilst most procedures are safe, there is considerable potential for damage to the hair and hair problems of acute onset, including hair breakage, hair loss and loss of condition, are frequently blamed on the last product used on the hair. Hair problems are particularly prevalent among people who repeatedly alter the natural style of their hair.

  1. Relationship between the prenatal exposure to low-level of mercury and the size of a newborn's cerebellum.

    PubMed

    Cace, I Bilic; Milardovic, A; Prpic, I; Krajina, R; Petrovic, O; Vukelic, P; Spiric, Z; Horvat, M; Mazej, D; Snoj, J

    2011-04-01

    Exposure to methylmercury at any stage of central nervous system development could induce alterations and result in severe congenital abnormalities. Total mercury level in maternal hair during pregnancy correlates well with blood levels of methylmercury and with total mercury levels in fetal brain. A prospective study has been conducted and a total of 137 childbearing women living at the coastal region with term, normal pregnancies were included and their newborns evaluated by ultrasonography. Mothers and their newborns are divided in two groups according to their hair mercury levels; examined group with high body levels of mercury (≥ 1 μg/g) and control group with low body levels of mercury (<1 μg/g). Neurosonographic examination was conducted to all newborns. Two dimensions of cerebellum in the sagital-medial plane have been measured: maximum height and width starting from the roof of the fourth chamber. Majority of mothers had hair mercury levels lower than 1 μg/g (N = 107). Mean value was 0.88 μg/g (SD 1.24), ranging from 0.02 to 8.71 μg/g. There was no significant difference between the two groups when it comes to the width of cerebellum (Mann-Whitney test: Z = 1471; p = 0.141). However, comparison related to the length of cerebellum shows statistically significant smaller cerebellum in newborns whose mother had hair mercury levels higher than 1 μg/g (Mann-Whitney test: Z = 2329; p = 0.019). Our results lead to a conclusion that prenatal exposure to, what we consider to be, low-levels of methylmercury does influence fetal brain development detected as decreased size of newborn's cerebellum. From a clinical point of view, a question related to the influence of prenatal low-level methylmercury exposure on fetal neurodevelopment remains open. Our further objectives are to direct the research towards performing detailed neuropshychological tests on children at the age of 18 months. Such tests could indicate the presence of subtle neurological or

  2. Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals

    PubMed Central

    Goodrich, Jaclyn M.; Wang, Yi; Gillespie, Brenda; Werner, Robert; Franzblau, Alfred; Basu, Niladri

    2012-01-01

    Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione s-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n=515), and total mercury content was measured. Average urine (1.06±1.24 ug/L) and hair mercury levels (0.49±0.63 ug/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5’), or both (SEPP1 3’UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). PMID:21967774

  3. Is paradoxical hair growth caused by low-level radiant exposure by home-use laser and intense pulsed light devices?

    PubMed

    Town, Godfrey; Bjerring, Peter

    2016-10-01

    This qualitative review of paradoxical hair growth, following professional treatments reviews, clarifies whether low fluence is the most probable cause of unwanted hair regrowth after at home light-based treatments. The proposed causes of unexpected hair regrowth are examined, and our scientific understanding of absorption and scattering of light in turbid tissue is reviewed. Published reports of paradoxical hair growth are assessed. Early laser hair removal studies failed to record the occurrence of hair induction despite the significant numbers of subjects treated. Neither published paradoxical hair growth studies following home-based laser or intense pulsed light (IPL) hair removal treatments, nor randomised or controlled studies documenting paradoxical hair growth following professional treatments could be found. Several authors directly proposed inflammatory response to be the primary cause of hair growth induction. It is unlikely that hair regrowth several centimetres or more away from the irradiated tissue can be attributed to the laser or IPL used. In many cases of paradoxical hair growth, other causes may be responsible for the unexpected hair growth. The primary cause of instances of 'true' paradoxical hair growth is probably limited to darker phototypes with one or more other characteristics including polycystic ovarian syndrome or other androgen hormonal irregularities following high energy treatments with the corresponding inflammatory sequelae.

  4. IRIS Summary and Supporting Documents for Methylmercury ...

    EPA Pesticide Factsheets

    In January 2001, U.S. EPA finalized the guidance for methylmercury in the water quality criteria for states and authorized tribes. The links below take you to the best resources for this guidance. This final Guidance for Implementing the January 2001 Methylmercury Water Quality Criterion provides technical guidance to states and authorized tribes on how they may want to use the January 2001 fish tissue-based recommended water quality criterion for methylmercury in surface water protection programs (e.g., TMDLs, NPDES permitting). The guidance addresses questions related to water quality standards adoption (e.g., site-specific criteria, variances), assessments, monitoring, TMDLs, and NPDES permitting. The guidance consolidates existing EPA guidance where relevant to mercury.

  5. Effects of breast feeding on neuropsychological development in a community with methylmercury exposure from seafood.

    PubMed

    Jensen, Tina Kold; Grandjean, Philippe; Jørgensen, Esben Budtz; White, Roberta F; Debes, Frodi; Weihe, Pál

    2005-09-01

    Breastfeeding has been associated with an advantage to infant neurobehavioral development, possibly in part due to essential nutrients in breast milk. However, breast milk may be contaminated by environmental neurotoxicants, such as methylmercury. In the Faroe Islands, where maternal consumption of pilot whale may cause transfer of marine toxicants into breast milk, a cohort of 1022 consecutive singleton births was generated during 1986-87. Methylmercury exposure was assessed from mercury concentrations in cord blood and in the hair of the child at age 12 months, and the duration of breastfeeding was recorded. At approximately 7 years of age, 917 (90%) of the children underwent detailed neurobehavioral examination. After adjustment for confounders, breastfeeding was associated with only marginally better neuropsychological performance on most tests. These associations were robust even after adjustment for cord-blood and hair mercury concentration at age 1 year. Thus, in this cohort of children with a relatively high prenatal toxicant exposure and potential exposure to neurotoxicants through breast milk, breastfeeding was associated with less benefits on neurobehavioral development than previously published studies though not associated with a deficit in neuropsychological performance at age 7. Although the advantage may be less, Faroese women can still safely breastfeed their children.

  6. Reanalysis of dose-response data from the Iraqi methylmercury poisoning episode

    SciTech Connect

    Crump, K.; Clewell, H.; Gearhart, J.

    1995-08-01

    Applying a hockey stick parametric dose-response model to data on late or retarded development in Iraqi children exposed in utero to methylmercury, with mercury (Hg) exposure characterized by the peak Hg concentration in mothers` hair during pregnancy, Cox et al. calculated the {open_quotes}best statistical estimate{close_quotes} of the threshold for health effects as 10 ppm Hg in hair with a 95% range of uncertainty of between 0 and 13.6 ppm. A new application of the hockey stick model to the Iraqi data shows, however, that the statistical upper limit of the threshold based on the hockey stick model could be as high as 255 ppm. Futhermore, the maximum likelihood estimate of the threshold using a different parametric model is virtually zero. These and other analyses demonstrate that threshold estimates based on parametric models exhibit high statistical variability and model dependency, and are highly sensitive to the precise definition of an abnormal response. Consequently, they are not a reliable basis for setting a reference dose (RfD) for methylmercury. Benchmark analyses and statistical analyses useful for deriving NOAELs are also presented. We believe these latter analyses-particularly the benchmark analyses-generally form a sounder basis for determining RfDs than the type of hockey stick analysis presented by Cox et al. However, the acute nature of the exposures, as well as other limitations in the Iraqi data suggest that other data may be more appropriate for determining acceptable human exposures to methylmercury. 24 refs., 5 figs., 2 tabs.

  7. Mercury stable isotope fractionation in a tropical ecosystem including human hair: New insights for an isotope balance

    NASA Astrophysics Data System (ADS)

    Laffont, Laure; Sonke, Jeroen; Maurice, Laurence; Behra, Philippe

    2010-05-01

    . Both anomalies ∆201Hg vs. ∆199Hg are linearly correlated with a slope of +1.12‰ for native hair and a mass dependant fractionation (MDF) of ~+2‰ has been evidenced between native communities hair and fish species constituting their diet. For the same fish species, MIF anomalies differ with floodplain lakes and drainage basins suggesting that the methylmercury (MMHg) analysed in fish caught in floodplain lake reflects the photodemethylation process while in the Beni R. mainstream the negative anomalies confirm that this photochemical reactions are limited. Within the aquatic food chain of an hydrosystem, it appears that MIF anomalies can trace the fish ecology and the aquatic photochemical processes, while mass dependent fractionation can trace the trophic level as a result of excretion and metabolic processes involving mercury in the body.

  8. Sediment microbial community composition and methylmercury pollution at four mercury mine-impacted sites.

    PubMed

    Batten, K M; Scow, K M

    2003-11-01

    Mercury pollution presents a globally significant threat to human and ecosystem health. An important transformation in the mercury cycle is the conversion of inorganic mercury to methylmercury, a toxic substance that negatively affects neurological function and bioaccumulates in food chains. This transformation is primarily bacterially mediated, and sulfate-reducing bacteria (SRB) have been specifically implicated as key mercury methylators in lake and estuarine sediments. This study used phospholipid fatty acid (PLFA) analysis to investigate sediment microbial community composition at four abandoned mercury mine-impacted sites in the California Coast Range: the Abbott, Reed, Sulphur Bank, and Mt. Diablo mines. Differences in watershed and hydrology among these sites were related to differences in microbial community composition. The Abbott and Sulphur Bank mines had the highest levels of methylmercury. Floc (a type of precipitate that forms when acid mine drainage contacts lake or river water) and sediment samples differed in terms of several important environmental variables and microbial community composition, but did not have statistically different methylmercury concentrations. Quantification of PLFA biomarkers for SRB (10Mel6:0 for Desulfobacter and i17:1 for Desulfovibrio) revealed that Desulfobacter and Desulfovibrio organisms made up higher percentages of overall microbial biomass at the Sulphur Bank and Mt. Diablo mines than at the Abbott and Reed mines. Correlations between these SRB biomarker fatty acids and methylmercury concentrations suggest that Desulfobacter and Desulfovibrio organisms may contribute to methylmercury production in the Abbott, Reed, and Sulphur Bank mines but may not be important contributors to methylmercury in the Mt. Diablo Mine.

  9. Hair density in African Americans.

    PubMed

    Sperling, L C

    1999-06-01

    The meager data on normal hair density in humans have been gathered from a predominantly white population. Examination of scalp biopsy specimens from African Americans suggests that hair density in this group may be lower than in whites. This study was performed to quantify any differences between white and African American patients. A retrospective case series of subjects who had undergone a biopsy of clinically healthy scalp skin. The 4-mm punch biopsy specimens were sectioned, and all follicles contained within the specimens were counted at various levels (suprabulbar, isthmus, and infundibulum) to arrive at the number and type of hairs present. Outpatient clinic in a tertiary care medical center. A consecutive sample of 22 African American and 12 white patients with clinically healthy scalp skin specimens that were studied and compared with previously reported data. Patients' age and total number of follicles, terminal follicles, vellus follicles, terminal anagen hairs, and terminal telogen hairs. Total hair density (number of follicles per 4-mm punch biopsy specimen) and total number of terminal follicles and terminal anagen hairs were significantly lower in African Americans (P<.001) than in whites and in a previously reported, predominantly white, population. Hair density in African Americans is significantly lower than that in whites, which must be taken into consideration when evaluating a biopsy specimen from an African American patient. Data previously collected from white patients may not provide adequate guidance when evaluating scalp biopsy specimens from African Americans and could lead to an incorrect diagnosis.

  10. [Hair mercury levels in different occupational groups in a gold mining zone in the north of Colombia].

    PubMed

    Olivero, J; Mendonza, C; Mestre, J

    1995-10-01

    Hair mercury analysis was carried out on a sample of 219 people living in the main gold mining zone of Colombia, 27 inhabitante of Cartagena City being taken as control sample. For data analysis the sample was divided by occupation and the corresponding the hair mercury concentrations (mean +/- SD) were found to be 5.23 +/- 5.78, 2.83 +/- 3.27, 2.4 +/- 2.02 and 1.33 +/- 0.74 micrograms/g for fishermen, miners, people of various other activities and the control sample, respectively. According to variance analysis and the Newman Keuls test, there were significant differences (p < 0.01) between the mercury concentrations for fishermen and those for the other groups. No significant differences were found for hair mercury and sex, non was any correlation with age detected; however, a low positive correlation (R = 0.15, p < 0.01) with the frequency of the consumption of fish was noted. The main symptoms of mercury poinsoning observed in the persons exposed were headache, oral lesions, metalic taste, loss of memory, and irritability.

  11. Evaluation of scalp hair nickel and chromium level changes in patients with fixed orthodontic appliance: a one-year follow-up study.

    PubMed

    Jamshidi, Saman; Rahmati Kamel, Manouchehr; Mirzaie, Maysam; Sarrafan, Ahmadreza; Khafri, Soraya; Parsian, Hadi

    2017-09-09

    The release of metal ions from orthodontic appliances is part of the dissolution and biomechanical processes of alloys. Nickel (Ni) and chromium (Cr) are the elements commonly used in the manufacture of various components of fixed orthodontic appliances, including bands, brackets and wires. This study was aimed to measure the Ni and Cr ions levels in the scalp hair of patients treated with fixed orthodontic appliances in comparison of the control group. The patient group consisted of 24 patients treated with fixed orthodontic appliances for one year, while the control group included 28 healthy individuals without orthodontic appliances. Analysis of the Cr and Ni was performed using atomic absorption spectrophotometer by graphite furnace method. The data were analyzed via student and paired samples t-test and ANOVA repeated measurement test. After one year, the levels of Ni and Cr in two groups showed significant differences (0.086 ± 0.007 and 0.258 ± 0.009 µg/g for control group and 0.149 ± 0.010 and 0.339 ± 0.013 µg/g for patient group, respectively for Ni and Cr, p < .001). ANCOVA test by removing the effects of age, gender and the baseline levels of Ni and Cr showed that changes in these ions in the scalp hair of both groups after one year were statistically significant. Due to the slightly elevated levels of Ni and Cr ions in the scalp hair of patients treated with fixed orthodontic appliances and considering the cytotoxic and allergic effects of these ions, changing the ingredients in fixed orthodontic appliances is suggested for the future.

  12. Global methylmercury exposure from seafood consumption and risk of developmental neurotoxicity: a systematic review

    PubMed Central

    Burke, Thomas A; Navas-Acien, Ana; Breysse, Patrick N; McGready, John; Fox, Mary A

    2014-01-01

    Abstract Objective To examine biomarkers of methylmercury (MeHg) intake in women and infants from seafood-consuming populations globally and characterize the comparative risk of fetal developmental neurotoxicity. Methods A search was conducted of the published literature reporting total mercury (Hg) in hair and blood in women and infants. These biomarkers are validated proxy measures of MeHg, a neurotoxin found primarily in seafood. Average and high-end biomarkers were extracted, stratified by seafood consumption context, and pooled by category. Medians for average and high-end pooled distributions were compared with the reference level established by a joint expert committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). Findings Selection criteria were met by 164 studies of women and infants from 43 countries. Pooled average biomarkers suggest an intake of MeHg several times over the FAO/WHO reference in fish-consuming riparians living near small-scale gold mining and well over the reference in consumers of marine mammals in Arctic regions. In coastal regions of south-eastern Asia, the western Pacific and the Mediterranean, average biomarkers approach the reference. Although the two former groups have a higher risk of neurotoxicity than the latter, coastal regions are home to the largest number at risk. High-end biomarkers across all categories indicate MeHg intake is in excess of the reference value. Conclusion There is a need for policies to reduce Hg exposure among women and infants and for surveillance in high-risk populations, the majority of which live in low-and middle-income countries. PMID:24700993

  13. Global methylmercury exposure from seafood consumption and risk of developmental neurotoxicity: a systematic review.

    PubMed

    Sheehan, Mary C; Burke, Thomas A; Navas-Acien, Ana; Breysse, Patrick N; McGready, John; Fox, Mary A

    2014-04-01

    To examine biomarkers of methylmercury (MeHg) intake in women and infants from seafood-consuming populations globally and characterize the comparative risk of fetal developmental neurotoxicity. A search was conducted of the published literature reporting total mercury (Hg) in hair and blood in women and infants. These biomarkers are validated proxy measures of MeHg, a neurotoxin found primarily in seafood. Average and high-end biomarkers were extracted, stratified by seafood consumption context, and pooled by category. Medians for average and high-end pooled distributions were compared with the reference level established by a joint expert committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). Selection criteria were met by 164 studies of women and infants from 43 countries. Pooled average biomarkers suggest an intake of MeHg several times over the FAO/WHO reference in fish-consuming riparians living near small-scale gold mining and well over the reference in consumers of marine mammals in Arctic regions. In coastal regions of south-eastern Asia, the western Pacific and the Mediterranean, average biomarkers approach the reference. Although the two former groups have a higher risk of neurotoxicity than the latter, coastal regions are home to the largest number at risk. High-end biomarkers across all categories indicate MeHg intake is in excess of the reference value. There is a need for policies to reduce Hg exposure among women and infants and for surveillance in high-risk populations, the majority of which live in low-and middle-income countries.

  14. ACCUMULATION OF METHYLMERCURY OR POLYCHLORINATED BIPHENYLS IN IN VITRO MODELS OF RAT NEURONAL TISSUE.

    EPA Science Inventory

    This manuscript reports data examining the accumulation of PCBs or methylmercury into the tissue of three commonly used in vitro neuronal models.

    ? The results demonstrate that these lipophilic compounds can accumulate to levels 5 to 100 fold higher than the surrounding s...

  15. Effects of Injected Methylmercury on the Hatching of Common Loon (Gavia immer) Eggs

    EPA Science Inventory

    To determine the level of in ovo methylmercury (MeHg) exposure that results in detrimental effects on fitness and survival of loon embryos and hatched chicks, we conducted a field study in which we injected eggs with various doses of MeHg on day 4 of incubation. Eggs were collect...

  16. Effects of Injected Methylmercury on the Hatching of Common Loon (Gavia immer) Eggs

    EPA Science Inventory

    To determine the level of in ovo methylmercury (MeHg) exposure that results in detrimental effects on fitness and survival of loon embryos and hatched chicks, we conducted a field study in which we injected eggs with various doses of MeHg on day 4 of incubation. Eggs were collect...

  17. Patterns and Consequences of in ovo Exposure to Methylmercury in Common Loons, poster presentation

    EPA Science Inventory

    A critical component of a common loon/mercury (Hg) risk assessment model under development is the determination of the concentration of Hg in eggs that poses a population level risk. We conducted a field study to (1) characterize in ovo methylmercury (MeHg) exposure in Wisconsin...

  18. Patterns and Consequences of in ovo Exposure to Methylmercury in Common Loons, poster presentation

    EPA Science Inventory

    A critical component of a common loon/mercury (Hg) risk assessment model under development is the determination of the concentration of Hg in eggs that poses a population level risk. We conducted a field study to (1) characterize in ovo methylmercury (MeHg) exposure in Wisconsin...

  19. Hair through the female life cycle.

    PubMed

    Messenger, A G

    2011-12-01

    At a population level female scalp hair growth shows features of regression with chronological ageing, although there is wide interindividual variation in timing and degree. The subjective assessment of hair loss is classically determined by hair density but it is apparent that other factors contribute to the clinical picture. Changes can occur in hair cycling, hair density, hair diameter and pigmentation, and possibly in structural qualities of the hair fibre. These changes are most pronounced in female pattern hair loss. Although conventionally considered as the female counterpart of male androgenetic alopecia the evidence that female pattern hair loss is androgen dependent is less clear cut than in men and it probably has a multifactorial basis. The emerging evidence implicating environmental factors is of particular interest as, unlike genes, such factors may be amenable to intervention. The clinical signs in women complaining of hair loss may be variable. In evaluating the patient complaining of hair loss, while true pathology must always be considered, the clinician needs to be aware of how age affects hair growth. These changes form the focus of this article. © 2011 The Author. BJD © 2011 British Association of Dermatologists.

  20. Effects of methylmercury and spatial complexity on foraging behavior and foraging efficiency in juvenile white ibises (Eudocimus albus).

    PubMed

    Adams, Evan M; Frederick, Peter C

    2008-08-01

    Methylmercury is a globally distributed neurotoxin, endocrine disruptor, and teratogen, the effects of which on wildlife at environmentally relevant levels are largely unknown. In birds, foraging efficiency and learning may be sensitive endpoints for sublethal methylmercury toxicity, and these endpoints also may be biologically relevant at the population level. In the present study, groups of wild-caught, prefledgling white ibises (Eudocimus albus) were raised in a free-flight, open-air aviary on diets that approximated the measured range of methylmercury exposure in the Everglades ecosystem (0, 0.05, 0.1, and 0.3 mg/kg/d). The effect of methylmercury exposure on group foraging efficiency was examined by allowing birds to forage on 200 fathead minnows (Pimephales promelas) in artificial ponds for 15 min by straining the arenas' contents through a seine net and counting all remaining prey. Additionally, we varied the difficulty of foraging by these tactile feeding birds by adding multiple levels of structural complexity (e.g., increased vegetation and prey refugia) to the pond. Structural complexity affected both foraging efficiency and the rate of increase in efficiency over time (improvement). Methylmercury exposure affected foraging efficiency (p = 0.03). It did not affect foraging improvement in the face of increasingly challenging environments, however, and the dose-response relationship was nonlinear (e.g., the control and high-exposure groups were the least efficient foragers). Evidence for an effect of methylmercury on foraging efficiency therefore was inconclusive because of unpredicted results and no interaction with time or habitat complexity. These data suggest a nonlinear dose-response relationship at low levels of methylmercury exposure; future research is needed to verify this hypothesis. This appears to be the first experimental demonstration of the effects of habitat complexity on foraging efficiency in long-legged wading birds.

  1. Effects of Relocation and Individual and Environmental Factors on the Long-Term Stress Levels in Captive Chimpanzees (Pan troglodytes): Monitoring Hair Cortisol and Behaviors.

    PubMed

    Yamanashi, Yumi; Teramoto, Migaku; Morimura, Naruki; Hirata, Satoshi; Inoue-Murayama, Miho; Idani, Gen'ichi

    2016-01-01

    Understanding the factors associated with the long-term stress levels of captive animals is important from the view of animal welfare. In this study, we investigated the effects of relocation in addition to individual and environmental factors related to social management on long-term stress level in group-living captive chimpanzees by examining behaviors and hair cortisol (HC). Specifically, we conducted two studies. The first compared changes in HC levels before and after the relocation of 8 chimpanzees (Study 1) and the second examined the relationship between individual and environmental factors and individual HC levels in 58 chimpanzees living in Kumamoto Sanctuary (KS), Kyoto University (Study 2). We hypothesized that relocation, social situation, sex, and early rearing conditions, would affect the HC levels of captive chimpanzees. We cut arm hair from chimpanzees and extracted and assayed cortisol with an enzyme immunoassay. Aggressive behaviors were recorded ad libitum by keepers using a daily behavior monitoring sheet developed for this study. The results of Study 1 indicate that HC levels increased during the first year after relocation to the new environment and then decreased during the second year. We observed individual differences in reactions to relocation and hypothesized that social factors may mediate these changes. In Study 2, we found that the standardized rate of receiving aggression, rearing history, sex, and group formation had a significant influence on mean HC levels. Relocation status was not a significant factor, but mean HC level was positively correlated with the rate of receiving aggression. Mean HC levels were higher in males than in females, and the association between aggressive interactions and HC levels differed by sex. These results suggest that, although relocation can affect long-term stress level, individuals' experiences of aggression and sex may be more important contributors to long-term stress than relocation alone.

  2. Effects of Relocation and Individual and Environmental Factors on the Long-Term Stress Levels in Captive Chimpanzees (Pan troglodytes): Monitoring Hair Cortisol and Behaviors

    PubMed Central

    Yamanashi, Yumi; Teramoto, Migaku; Morimura, Naruki; Hirata, Satoshi; Inoue-Murayama, Miho; Idani, Gen'ichi

    2016-01-01

    Understanding the factors associated with the long-term stress levels of captive animals is important from the view of animal welfare. In this study, we investigated the effects of relocation in addition to individual and environmental factors related to social management on long-term stress level in group-living captive chimpanzees by examining behaviors and hair cortisol (HC). Specifically, we conducted two studies. The first compared changes in HC levels before and after the relocation of 8 chimpanzees (Study 1) and the second examined the relationship between individual and environmental factors and individual HC levels in 58 chimpanzees living in Kumamoto Sanctuary (KS), Kyoto University (Study 2). We hypothesized that relocation, social situation, sex, and early rearing conditions, would affect the HC levels of captive chimpanzees. We cut arm hair from chimpanzees and extracted and assayed cortisol with an enzyme immunoassay. Aggressive behaviors were recorded ad libitum by keepers using a daily behavior monitoring sheet developed for this study. The results of Study 1 indicate that HC levels increased during the first year after relocation to the new environment and then decreased during the second year. We observed individual differences in reactions to relocation and hypothesized that social factors may mediate these changes. In Study 2, we found that the standardized rate of receiving aggression, rearing history, sex, and group formation had a significant influence on mean HC levels. Relocation status was not a significant factor, but mean HC level was positively correlated with the rate of receiving aggression. Mean HC levels were higher in males than in females, and the association between aggressive interactions and HC levels differed by sex. These results suggest that, although relocation can affect long-term stress level, individuals’ experiences of aggression and sex may be more important contributors to long-term stress than relocation alone

  3. Somatosensory disturbance by methylmercury exposure.

    PubMed

    Takaoka, Shigeru; Kawakami, Yoshinobu; Fujino, Tadashi; Oh-ishi, Fumihiro; Motokura, Fukuo; Kumagai, Yoshio; Miyaoka, Tetsu

    2008-05-01

    Minamata disease is methylmercury poisoning from consuming fish and shellfish contaminated by industrial waste. The polluted seafood was widely consumed in the area around Minamata, but many individuals were never examined for or classified as having Minamata disease. Following the determination of the Supreme Court of Japan in October 2004 that the Japanese Government was responsible for spreading Minamata disease, over 13,000 residents came forward to be examined for Minamata disease. We studied 197 residents from the Minamata area who had a history of fish consumption during the polluted period to determine the importance of sensory symptoms and findings in making a diagnosis of Minamata disease. We divided the exposed subjects into non-complicated (E) and complicated (E+N) groups based on the absence or presence of other neurological or neurologically related disorders and compared them to residents in control area (C) after matching for age and sex. We quantitatively measured four somatosensory modalities (minimal tactile sense by Semmes-Weinstein monofilaments, vibration sense, position sense, and two-point discrimination) and did psychophysical tests of fine-surface-texture discrimination. Subjective complaints were higher in groups E and E+N than C. Over 90% of E+N and E subjects displayed a sensory disturbance on conventional neurological examination and 28% had visual constriction. About 50% of the E and E +N groups had upper and lower extremity ataxia and about 70% had truncal ataxia. The prevalence of these neurological findings was significantly higher in exposed subjects than controls. All sensory modalities were impaired in the E and E+N groups. All four quantitatively measured sensory modalities were correlated. The prevalence of complaints, neurological findings, and sensory impairment was similar or a little worse in group E+N than in group E. We conclude that sensory symptoms and findings are important in making the diagnosis of Minamata disease

  4. Oxidative stress in songbirds exposed to dietary methylmercury.

    PubMed

    Henry, Katie A; Cristol, Daniel A; Varian-Ramos, Claire W; Bradley, Eric L

    2015-04-01

    Long-term, sublethal methylmercury exposure can cause reproductive depression, immune suppression, endocrine disruption and other problems in birds. We used two biomarkers to detect oxidative stress in livers of zebra finches (Taeniopygia guttata) developmentally exposed to sublethal levels of dietary methylmercury (0.0, 0.3, 0.6, 1.2, or 2.4 μg/g wet weight in diet). Our findings indicate that young adult finches exposed to environmentally relevant concentrations of mercury in ovo and through their diets, exhibited oxidative stress in their livers. We measured the ratio of the antioxidant glutathione in its reduced form (GSH) versus its oxidized form (GSSG) and the activity of the superoxide dismutase (SOD) enzyme suite. Blood total mercury served as a proxy for liver mercury concentration, and was on average 8.4 times the dietary dose (e.g., birds consuming 0.6 μg/g had blood mercury levels of ~5 μg/g on a wet weight basis). Consistent with what is known from large, aquatic bird species, there was a significant, negative relationship between GSH/GSSG ratios and tissue mercury concentrations, which is indicative of oxidative stress. This relationship was driven by a significant increase in the oxidized glutathione in the livers of birds with higher blood mercury levels. SOD activity was also found to have a significant, negative relationship with blood mercury.

  5. Levels of mercury in scalp hair of fishermen and their families from Camara de Lobos-Madeira (Portugal): A preliminary study

    SciTech Connect

    Gaggi, C.; Zino, F.; Duccini, M.; Renzoni, A.

    1996-12-31

    Mercury is probably one of the most investigated natural and anthropogenic contaminants, especially in aquatic environments. Among the inorganic forms, elemental mercury (HgO) presents a marked tendency to reach the air as vapor, and in terrestrial systems to bioaccumulate in plant biomass, whereas other inorganic compounds (e.g., mercury sulphide) are characterized by low mobility and bioavailability. These last compounds once in water (and especially at the water-sediment interface) can undergo a process of methylation. Methylmercury (MeHg) is readily bioaccumulated by aquatic organisms and leads to a phenomenon of enrichment from lower to higher trophic level. The extensive literature on MeHg and human health shows that the consumption of fish and/or shellfish is the main source of exposure, the contribution from air and water being negligible and mainly related to inorganic forms. A human population consuming large amounts of seafood with high MeHg levels can be considered at risk when consumption exceeds a certain amount. This level has been set by the WHO and other agencies, at 300 {mu}g/week of total mercury (totHg) of which there should be no more than 200 {mu}g as MeHg. The nervous system is the principal target of the effects of MeHg in humans. The most common functions affected are the sensory, visual and auditory functions, together with those of the cerebellum, which is concerned with coordination. As far as prenatal exposure is concerned, the developing central nervous system of humans and animals has been found to be more sensitive to damage from MeHg than the adult nervous system. This preliminary study obtains and examines information about eating habits and general health of a group of fisherman and their families living in a fishing village, at high risk because of the high frequency of seafood in their normal diet. 17 refs., 1 fig., 1 tab.

  6. Hair counts from normal scalp biopsy in Taiwan.

    PubMed

    Ko, Jui-Hung; Huang, Yu-Huei; Kuo, Tseng-Tong

    2012-09-01

    Horizontal scalp biopsy is a better method to use when evaluating hair disorders, but an accurate diagnosis requires quantitative data regarding normal hair counts to be used as a control, which are currently available only for Caucasians, African Americans, Koreans, and Iranians. To evaluate scalp hair counts in the Taiwanese population. Two 4-mm punch biopsies were taken from clinically normal-looking scalp skin of 31 patients who underwent scalp surgery for non-hair-loss disorders. Punch biopsy specimens were sectioned horizontally at the sebaceous gland level and the number of follicular units, terminal hairs including anagen and telogen hairs, and vellus hairs were counted and compared with other published data. The numbers of hairs were also compared between the sexes, different age groups, and different anatomical locations of the scalp. The average counts of total hairs, terminal hairs, vellus hairs, and follicular units per 4-mm punch scalp skin were 21.3, 20.5, 0.8, and 9.4, respectively. The mean ratio of anagen hair to telogen hair was 91.6:8.4 and of terminal hair to vellus hair was 25.3:1. The average density of hair follicles was 1.69 mm(2). The mean counts of terminal hairs, total hairs, follicular units, and hair follicles/mm(2) were significantly different between different age groups. Differences in hair count parameters were recognized between different ethnic groups. Parameters of hair density established in the Taiwanese population will provide clinicians with useful reference data for the evaluation of hair disorders in Asians. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  7. Is Low Non-Lethal Concentration of Methylmercury Really Safe? A Report on Genotoxicity with Delayed Cell Proliferation.

    PubMed

    Crespo-Lopez, María Elena; Costa-Malaquias, Allan; Oliveira, Edivaldo H C; Miranda, Moysés S; Arrifano, Gabriela P F; Souza-Monteiro, José R; Sagica, Fernanda Espirito-Santo; Fontes-Junior, Enéas A; Maia, Cristiane S F; Macchi, Barbarella M; do Nascimento, José Luiz M

    2016-01-01

    Human exposure to relatively low levels of methylmercury is worrying, especially in terms of its genotoxicity. It is currently unknown as to whether exposure to low levels of mercury (below established limits) is safe. Genotoxicity was already shown in lymphocytes, but studies with cells of the CNS (as the main target organ) are scarce. Moreover, disturbances in the cell cycle and cellular proliferation have previously been observed in neuronal cells, but no data are presently available for glial cells. Interestingly, cells of glial origin accumulate higher concentrations of methylmercury than those of neuronal origin. Thus, the aim of this work was to analyze the possible genotoxicity and alterations in the cell cycle and cell proliferation of a glioma cell line (C6) exposed to a low, non-lethal and non-apoptotic methylmercury concentration. Biochemical (mitochondrial activity) and morphological (integrity of the membrane) assessments confirmed the absence of cell death after exposure to 3 μM methylmercury for 24 hours. Even without promoting cell death, this treatment significantly increased genotoxicity markers (DNA fragmentation, micronuclei, nucleoplasmic bridges and nuclear buds). Changes in the cell cycle profile (increased mitotic index and cell populations in the S and G2/M phases) were observed, suggesting arrest of the cycle. This delay in the cycle was followed, 24 hours after methylmercury withdrawal, by a decrease number of viable cells, reduced cellular confluence and increased doubling time of the culture. Our work demonstrates that exposure to a low sublethal concentration of MeHg considered relatively safe according to current limits promotes genotoxicity and disturbances in the proliferation of cells of glial origin with sustained consequences after methylmercury withdrawal. This fact becomes especially important, since this cellular type accumulates more methylmercury than neurons and displays a vital role protecting the CNS, especially in

  8. Is Low Non-Lethal Concentration of Methylmercury Really Safe? A Report on Genotoxicity with Delayed Cell Proliferation

    PubMed Central

    Crespo-Lopez, María Elena; Costa-Malaquias, Allan; Oliveira, Edivaldo H. C.; Miranda, Moysés S.; Arrifano, Gabriela P. F.; Souza-Monteiro, José R.; Sagica, Fernanda Espirito-Santo; Fontes-Junior, Enéas A.; Maia, Cristiane S. F.; Macchi, Barbarella M.; do Nascimento, José Luiz M.

    2016-01-01

    Human exposure to relatively low levels of methylmercury is worrying, especially in terms of its genotoxicity. It is currently unknown as to whether exposure to low levels of mercury (below established limits) is safe. Genotoxicity was already shown in lymphocytes, but studies with cells of the CNS (as the main target organ) are scarce. Moreover, disturbances in the cell cycle and cellular proliferation have previously been observed in neuronal cells, but no data are presently available for glial cells. Interestingly, cells of glial origin accumulate higher concentrations of methylmercury than those of neuronal origin. Thus, the aim of this work was to analyze the possible genotoxicity and alterations in the cell cycle and cell proliferation of a glioma cell line (C6) exposed to a low, non-lethal and non-apoptotic methylmercury concentration. Biochemical (mitochondrial activity) and morphological (integrity of the membrane) assessments confirmed the absence of cell death after exposure to 3 μM methylmercury for 24 hours. Even without promoting cell death, this treatment significantly increased genotoxicity markers (DNA fragmentation, micronuclei, nucleoplasmic bridges and nuclear buds). Changes in the cell cycle profile (increased mitotic index and cell populations in the S and G2/M phases) were observed, suggesting arrest of the cycle. This delay in the cycle was followed, 24 hours after methylmercury withdrawal, by a decrease number of viable cells, reduced cellular confluence and increased doubling time of the culture. Our work demonstrates that exposure to a low sublethal concentration of MeHg considered relatively safe according to current limits promotes genotoxicity and disturbances in the proliferation of cells of glial origin with sustained consequences after methylmercury withdrawal. This fact becomes especially important, since this cellular type accumulates more methylmercury than neurons and displays a vital role protecting the CNS, especially in

  9. Processing of complementary food does not increase hair zinc levels and growth of infants in Kilosa district, rural Tanzania.

    PubMed

    Lachat, Carl K; Van Camp, John H; Mamiro, Peter S; Wayua, Francis Obuoro; Opsomer, Anne S; Roberfroid, Dominique A; Kolsteren, Patrick W

    2006-01-01

    A community-based, randomized, placebo-controlled, double-blind trial was conducted from March 2001 to March 2002 in Kilosa, a rural district of Morogoro Region in Tanzania. One hundred and fifty-eight infants were selected randomly from lists of local Maternal and Child Health Care Centres and received either processed complementary food (PCF) or unprocessed complementary food (UPCF) from age 6 to 12 months. Processing increased Zn solubility and energy density of the porridge prepared from the complementary food (CF) as determined in vitro. Phytate:Zn molar ratio of the PCF and UPCF was 25.8 and 47.5, respectively. Under the study conditions, the processing of CF did not improve Zn status as measured by hair analysis. No significant correlations were found between hair Zn values and anthropometric measurements. Our findings suggest that processing alone of cereal-based CF may be insufficient to ensure an adequate supply of Zn to improve growth and Zn status of infants. Dietary modification to tackle Zn deficiencies in similar target groups may therefore only be successful when other Zn-rich foods such as meat and fish are included.

  10. Hormetic effect of methylmercury on Caenorhabditis elegans

    SciTech Connect

    Helmcke, Kirsten J. Aschner, Michael

    2010-10-15

    Research has demonstrated the toxic effects of methylmercury (MeHg), yet molecular mechanisms underlying its toxicity are not completely understood. Caenorhabditis elegans (C. elegans) offers a unique biological model to explore mechanisms of MeHg toxicity given many advantages associated with its ease of use and genetic power. Since our previous work indicated neurotoxic resistance of C. elegans to MeHg, the present study was designed to examine molecular mechanisms associated with this resistance. We hypothesized MeHg would induce expression of gst, hsp or mtl in vivo since glutathione (GSH), heat shock proteins (HSPs), and metallothioneins (MTs) have shown involvement in MeHg toxicity. Our studies demonstrated a modest, but significant increase in fluorescence in gst-4::GFP and mtl-1::GFP strains at an acute, low L1 MeHg exposure, whereas chronic L4 MeHg exposure induced expression of gst-4::GFP and hsp-4::GFP. Knockout gst-4 animals showed no alterations in lethality sensitivity compared to wildtype animals whereas mtl knockouts displayed increased sensitivity to MeHg exposure. GSH levels were increased by acute MeHg treatment and depleted with chronic exposure. We also demonstrate that MeHg induces hormesis, a phenotype whereby a sublethal exposure to MeHg rendered C. elegans resistant to subsequent exposure to the organometal. The involvement of gst-4, hsp-4, mtl-1, and mtl-2 in hormesis was examined. An increase in gst-4::GFP expression after a low-dose acute exposure to MeHg indicated that gst-4 may be involved in this response. Our results implicate GSH, HSPs, and MTs in protecting C. elegans from MeHg toxicity and show a potential role of gst-4 in MeHg-induced hormesis.

  11. Evaluation of Serum, Urine, and Hair Chromium Levels as Indices of Chromium Exposure and the Relationship of these Indices to Serum Lipid and Insulin Levels.

    NASA Astrophysics Data System (ADS)

    Randall, Janis Avril

    Concentrations of chromium (Cr) in hair, serum, and urine, and serum concentrations of insulin and lipids of a selected group of men exposed to trivalent Cr (Cr III) were compared with those of men not exposed to Cr. Seventy -three tannery workers (TW) (mean age 37 +/- 12 years) from four Southern Ontario tanneries and fifty-two control subjects (CS) (mean age 41 +/- 13 years), matched for age, race, and socioeconomic status, from the Guelph and Toronto areas participated. The median hair and serum Cr concentrations for the TW were significantly higher (p < 0.01) than for the CS (hair Cr 453 vs 124 ng/g; serum Cr 0.49 vs 0.15 ng/ml). Median urinary Cr/creatinine ratios (Cr/Cre) for the TW on Monday morning (0.83 ng/mg) and Friday afternoon (0.68 ng/mg) were also significantly higher (p < 0.01, p < 0.01, respectively) than the median urinary Cr/Cre ratio for the urine samples collected on a Friday afternoon from the CS (0.18 ng/mg). For the TW, the median Friday urinary Cr/Cre ratio was significantly higher (p = 0.03) than the corresponding Monday Cr/Cre ratio. For the TW, urinary Cr/Cre ratios (Monday and Friday) were correlated significantly and positively with both Cr concentrations in serum (r = 0.45, p < 0.01; r = 0.71, p < 0.01, respectively) and in hair (r = 0.43, p < 0.01; r = 0.64, p < 0.01, respectively). Concentrations of Cr in hair and in serum were also significantly correlated (r = 0.52, p < 0.01). There were no significant differences between the TW and CS in serum concentrations of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), or triglycerides, or in calculated values for low-density lipoprotein cholesterol, %HDL-C, and TC/HDL-C. Likewise, no significant differences in serum insulin concentrations were noted between the two groups. Results of this study indicate that Cr III, from compounds used in the leather tanning industry, is absorbed and retained. Absorption of Cr III had no significant effect on serum insulin

  12. Hair Pulling (Trichotillomania)

    MedlinePlus

    ... Facts for Families Guide Facts for Families - Vietnamese Hair Pulling (Trichotillomania) No. 96; Reviewed July 2013 It ... for children and adolescents to play with their hair. However, frequent or obsessive hair pulling can lead ...

  13. Reduced memory skills and increased hair cortisol levels in recent Ecstasy/MDMA users: significant but independent neurocognitive and neurohormonal deficits.

    PubMed

    Downey, Luke A; Sands, Helen; Jones, Lewis; Clow, Angela; Evans, Phil; Stalder, Tobias; Parrott, Andrew C

    2015-05-01

    The goals of this study were to measure the neurocognitive performance of recent users of recreational Ecstasy and investigate whether it was associated with the stress hormone cortisol. The 101 participants included 27 recent light users of Ecstasy (one to four times in the last 3 months), 23 recent heavier Ecstasy users (five or more times) and 51 non-users. Rivermead paragraph recall provided an objective measure for immediate and delayed recall. The prospective and retrospective memory questionnaire provided a subjective index of memory deficits. Cortisol levels were taken from near-scalp 3-month hair samples. Cortisol was significantly raised in recent heavy Ecstasy users compared with controls, whereas hair cortisol in light Ecstasy users was not raised. Both Ecstasy groups were significantly impaired on the Rivermead delayed word recall, and both groups reported significantly more retrospective and prospective memory problems. Stepwise regression confirmed that lifetime Ecstasy predicted the extent of these memory deficits. Recreational Ecstasy is associated with increased levels of the bio-energetic stress hormone cortisol and significant memory impairments. No significant relationship between cortisol and the cognitive deficits was observed. Ecstasy users did display evidence of a metacognitive deficit, with the strength of the correlations between objective and subjective memory performances being significantly lower in the Ecstasy users. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Comparison of productive and reproductive performance and hair cortisol levels between Brown Swiss cross-bred and Holstein cows housed in the same barn.

    PubMed

    Endo, Natsumi; Kuroki, Reimi; Tanaka, Tomomi

    2017-10-01

    The productive and reproductive characteristics of Brown Swiss (B) cross-bred cows were investigated by comparing with those of Holstein (H) cows housed in the same barn. Additionally, their hair cortisol levels were analyzed to evaluate the extent of stress experienced during dry and lactation periods. B cross-bred cows had lower milk yields and higher milk fat rates than H cows. Reproductive records showed that days from parturition to first artificial insemination (AI) in B cross-bred (n = 16) and H (n = 27) cows were not significantly different, but conception rate at first AI of B cross-bred cows tended to be higher than that of H cows. Percentage of B cross-bred cows that resumed ovarian cyclic activity within 45 days after parturition was higher than that of H cows (6/6 (100%) and 5/11 (45.5%), P < 0.05), and B cross-bred cows had higher body condition scores at that time. Hair cortisol level at 60 to 90 days after parturition in H cows increased significantly compared with in the dry period, and it was higher than that of B cows during the same period. These results suggest that B cross-bred cows experience less metabolic stress during early lactation, which may result in earlier resumption of reproductive function. © 2017 Japanese Society of Animal Science.

  15. Proteomic Analysis of Hair Follicles

    NASA Astrophysics Data System (ADS)

    Ishioka, Noriaki; Terada, Masahiro; Yamada, Shin; Seki, Masaya; Takahashi, Rika; Majima, Hideyuki J.; Higashibata, Akira; Mukai, Chiaki

    2013-02-01

    Hair root cells actively divide in a hair follicle, and they sensitively reflect physical conditions. By analyzing the human hair, we can know stress levels on the human body and metabolic conditions caused by microgravity environment and cosmic radiation. The Japan Aerospace Exploration Agency (JAXA) has initiated a human research study to investigate the effects of long-term space flight on gene expression and mineral metabolism by analyzing hair samples of astronauts who stayed in the International Space Station (ISS) for 6 months. During long-term flights, the physiological effects on astronauts include muscle atrophy and bone calcium loss. Furthermore, radiation and psychological effects are important issue to consider. Therefore, an understanding of the effects of the space environment is important for developing countermeasures against the effects experienced by astronauts. In this experiment, we identify functionally important target proteins that integrate transcriptome, mineral metabolism and proteome profiles from human hair. To compare the protein expression data with the gene expression data from hair roots, we developed the protein processing method. We extracted the protein from five strands of hair using ISOGEN reagents. Then, these extracted proteins were analyzed by LC-MS/MS. These collected profiles will give us useful physiological information to examine the effect of space flight.

  16. Assessing and Managing Methylmercury Risks Associated With Power Plant Mercury Emissions in the United States

    PubMed Central

    Charnley, Gail

    2006-01-01

    Abstract and Introduction Abstract Until the Clean Air Mercury Rule was signed in March 2005, coal-fired electric utilities were the only remaining, unregulated major source of industrial mercury emissions in the United States. Proponents of coal-burning power plants assert that methylmercury is not a hazard at the current environmental levels, that current technologies for limiting emissions are unreliable, and that reducing mercury emissions from power plants in the United States will have little impact on environmental levels. Opponents of coal-burning plants assert that current methylmercury exposures from fish are damaging to the developing nervous system of infants, children, and the fetus; that current technology can significantly limit emissions; and that reducing emissions will reduce exposure and risk. One concern is that local mercury emissions from power plants may contribute to higher local exposure levels, or “hot spots.” The impact of the Mercury Rule on potential hot spots is uncertain due to the highly site-specific nature of the relationship between plant emissions and local fish methylmercury levels. The impact on the primary source of exposure in the United States, ocean fish, is likely to be negligible due to the contribution of natural sources and industrial sources outside the United States. Another debate centers on the toxic potency of methylmercury, with the scientific basis of the US Environmental Protection Agency's (EPA's) recommended exposure limit questioned by some and defended by others. It is likely that the EPA's exposure limit may be appropriate for combined exposure to methylmercury and polychlorinated biphenyls (PCBs), but may be lower than the available data suggest is necessary to protect children from methylmercury alone. Mercury emissions from power plants are a global problem. Without a global approach to developing and implementing clean coal technologies, limiting US power plant emissions alone will have little

  17. Arsenic Exposure within the Korean Community (United States) Based on Dietary Behavior and Arsenic Levels in Hair, Urine, Air, and Water

    PubMed Central

    Cleland, Bill; Tsuchiya, Ami; Kalman, David A.; Dills, Russell; Burbacher, Thomas M.; White, Jim W.; Faustman, Elaine M.; Mariën, Koenraad

    2009-01-01

    Background Determining arsenic exposure in groups based on geographic location, dietary behaviors, or lifestyles is important, as even moderate exposures may lead to health concerns. Objectives/Methods The Korean community in Washington State, represents a group warranting investigation, as they consume foods (e.g., shellfish, rice, finfish, and seaweed) known to contain arsenic. As part of the Arsenic Mercury Intake Biometric Study, we examined the arsenic levels in hair and urine along with the diets of 108 women of childbearing age from within this community. Arsenic levels in indoor air and drinking water were also investigated, and shellfish commonly consumed were collected and analyzed for total and speciated arsenic. Results The six shellfish species analyzed (n = 667) contain total arsenic (range, 1–5 μg/g) but are a small source of inorganic arsenic (range, 0.01–0.12 μg/g). Six percent of the individuals may have elevated urinary inorganic arsenic levels (> 10 μg/L) due to diet. Seaweed, rice, shellfish, and finfish are principal sources for total arsenic intake/excretion based on mass balance estimates. Rice consumption (163 g/person/day) may be a significant source of inorganic arsenic. Air and water are not significant sources of exposure. Hair is a poor biometric for examining arsenic levels at low to moderate exposures. Conclusions We conclude that a portion of this community may have dietary inorganic arsenic exposure resulting in urine levels exceeding 10 μg/L. Although their exposure is below that associated with populations exposed to high levels of arsenic from drinking water (> 100 μg/L), their exposure may be among the highest in the United States. PMID:19440504

  18. Porphyrins as biomarkers of methylmercury and PCB exposure in experimental quail

    SciTech Connect

    Leonzio, C.; Fossi, M.C.; Casini, S.

    1996-02-01

    Chemicals such as heavy metals and polyhalogenated hydrocarbons have a high capacity to interfere with the enzymatic processes responsible for haem biosynthesis. These compounds can produce accumulation in tissues and organs and increased elimination of porphyrins in excreta. The development of fast and easy analytical methods and the wide variety of biological media in which porphynins can be detected have suggested their use as biomarkers of environmental pollution. The analysis of porphynins in the excreta is of special interest because it enables non-destructive monitoring of wild animals in the assessment of threatened or endangered species. Methylmercury and PCBs are ubiquitous global pollutants and there is evidence they accumulate in ternfuinal consumers, particularly those belonging to marine trophic chain. There have been some reports on methylmercury-induced and PCB-induced porphyria but little data on their combined effect. In order to investigate the quality of porphyrins as biomarkers we performed an experiment in which Japanese quail were fed a diet containing methylmercury and polychlorobyphenyls (PCBs as Arochlor 1260) individually or combined in different ratios. The present study aims to provide preliminary data on liver and fecal levels of porphynins in response to methylmercury and PCB administration, and on whether the indicator is sensitive to synergism or antagonism between the two compounds, administered simultaneously.

  19. Hormesis associated with a low dose of methylmercury injected into mallard eggs

    USGS Publications Warehouse

    Heinz, Gary H.; Hoffman, David J.; Klimstra, Jon D.; Stebbins, Katherine R.; Kondrad, Shannon L.; Erwin, Carol A.

    2012-01-01

    We injected mallard (Anas platyrhynchos) eggs with methylmercury chloride at doses of 0, 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 μg mercury/g egg contents on a wet-weight basis. A case of hormesis seemed to occur because hatching success of eggs injected with 0.05 μg mercury (the lowest dose) was significantly greater (93.3%) than that of controls (72.6%), whereas hatching success decreased at progressively greater doses of mercury. Our finding of hormesis when a low dose of methylmercury was injected into eggs agrees with a similar observation in a study in which a group of female mallards was fed a low dietary concentration of methylmercury and hatching of their eggs was significantly better than that of controls. If methylmercury has a hormetic effect at low concentrations in avian eggs, these low concentrations may be important in a regulatory sense in that they may represent a no-observed adverse effect level (NOAEL).

  20. Trace Element Levels in Scalp Hair of School Children in Shigatse, Tibet, an Endemic Area for Kaschin-Beck Disease (KBD).

    PubMed

    Guo, Ya'nan; Li, Hairong; Yang, Linsheng; Li, Yonghua; Wei, Binggan; Wang, Wuyi; Gong, Hongqiang; Guo, Min; Nima, Cangjue; Zhao, Shengcheng; Wang, Jing

    2017-03-10

    Kaschin-Beck disease (KBD) is an endemic osteoarthritis, and the etiology is closely related with levels of trace elements in the human body. Currently, it is clear that the selenium (Se) status of children in KBD areas is lower than that in non-KBD areas in the Tibetan Plateau, whereas role of other elements are yet unknown. This study aimed to assess some essential trace elements (Se, Mo, Mn, Zn, Fe, Cu, Co, and Sr) in children using scalp hair as a biomarker, and 157 samples from school children aged 8-14 years old were collected from both KBD and non-KBD areas in Shigatse, Tibet. Se and Mo were measured by inductive coupled plasma mass spectrometry, and the other elements were determined by inductive coupled plasma optical emission spectrometry. Compared with the non-KBD areas, Se, Mo, Mn, Fe, Zn, Co, and Sr levels of children in KBD areas were found to be significantly different (P < 0.05); while in linear discriminant analysis, only Se and Zn were found to contribute to the KBD prevalence in the study area. The hair Se level of children in KBD areas ranged from 0.115 to 0.299 mg/kg, while in non-KBD areas it ranged from 0.135 to 0.519 mg/kg. The Zn content of children's hair was between 83 and 207 mg/kg in KBD areas, while it was 37 and 219 mg/kg in non-KBD areas. Lower Se and higher Zn levels in children in KBD areas was found when compared with non-KBD groups. In addition, Mo levels were found to be different between KBD areas and non-KBD areas on the opposite side of the Yarlung Zangbo River, but no close relationship was shown because there was no difference compared with the non-KBD area on the same side of the river. Our observations suggest that Se deficiency is still an important factor for the occurrence and prevalence of KBD, while the relationship between Zn and KBD needs to be further explored in the Tibetan Plateau.

  1. Hair cortisol reflects socio-economic factors and hair zinc in preschoolers.

    PubMed

    Vaghri, Ziba; Guhn, Martin; Weinberg, Joanne; Grunau, Ruth E; Yu, Wayne; Hertzman, Clyde

    2013-03-01

    This study examined the relationship between children's hair cortisol and socioeconomic status of the family, as measured by parental education and income. Low family socioeconomic status has traditionally been considered a long-term environmental stressor. Measurement of hair cortisol provides an integrated index of cumulative stress exposure across an extended period of time. The present study is the first to examine the relationship between hair cortisol and parental education as well as parental income in a representative sample of preschoolers. Data on hair cortisol, family income, and parental education were collected for a representative sample of 339 children (Mean age=4.6 years; SD=.5 years) from across 23 neighbourhoods of the city of Vancouver, Canada. As maternal education was shown previously to be associated with hair zinc level, hair zinc measurements were included as well in order to explore potential relationships between hair zinc and hair cortisol. The relationship between hair cortisol and parental education was examined using hierarchical regression, with hair zinc, gender, age, and single parenthood included as covariates. Maternal and paternal education both were correlated significantly with hair cortisol (r=-0.18; p=.001). The relationship remained statistically significant even after controlling for all demographic covariates as well as for hair zinc and after taking the neighbourhood-level clustering of the data into account. Parental income, on the other hand, was not related significantly to children's hair cortisol. This study provides evidence that lower maternal and paternal education are associated with higher hair cortisol levels. As hair cortisol provides an integrated index of cortisol exposure over an extended time period, these findings suggest a possibly stable influence of SES on the function of the hypothalamic-pituitary-adrenal (HPA) axis. Cumulative exposure to cortisol during early childhood may be greater in children

  2. Hair cortisol reflects socio-economic factors and hair zinc in preschoolers

    PubMed Central

    Vaghri, Ziba; Guhn, Martin; Weinberg, Joanne; Grunau, Ruth E.; Yu, Wayne; Hertzman, Clyde

    2016-01-01

    Summary This study examined the relationship between children’s hair cortisol and socioeconomic status of the family, as measured by parental education and income. Low family socioeconomic status has traditionally been considered a long-term environmental stressor. Measurement of hair cortisol provides an integrated index of cumulative stress exposure across an extended period of time. The present study is the first to examine the relationship between hair cortisol and parental education as well as parental income in a representative sample of preschoolers. Data on hair cortisol, family income, and parental education were collected for a representative sample of 339 children (Mean age = 4.6 years; SD = .5 years) from across 23 neighbourhoods of the city of Vancouver, Canada. As maternal education was shown previously to be associated with hair zinc level, hair zinc measurements were included as well in order to explore potential relationships between hair zinc and hair cortisol. The relationship between hair cortisol and parental education was examined using hierarchical regression, with hair zinc, gender, age, and single parenthood included as covariates. Maternal and paternal education both were correlated significantly with hair cortisol (r = −0.18; p = .001). The relationship remained statistically significant even after controlling for all demographic covariates as well as for hair zinc and after taking the neighbourhood-level clustering of the data into account. Parental income, on the other hand, was not related significantly to children’s hair cortisol. This study provides evidence that lower maternal and paternal education are associated with higher hair cortisol levels. As hair cortisol provides an integrated index of cortisol exposure over an extended time period, these findings suggest a possibly stable influence of SES on the function of the hypothalamic–pituitary–adrenal (HPA) axis. Cumulative exposure to cortisol during early childhood may

  3. Efficacy and safety of a low-level laser device in the treatment of male and female pattern hair loss: a multicenter, randomized, sham device-controlled, double-blind study.

    PubMed

    Jimenez, Joaquin J; Wikramanayake, Tongyu C; Bergfeld, Wilma; Hordinsky, Maria; Hickman, Janet G; Hamblin, Michael R; Schachner, Lawrence A

    2014-04-01

    Male and female pattern hair loss are common, chronic dermatologic disorders with limited therapeutic options. In recent years, a number of commercial devices using low-level laser therapy have been promoted, but there have been little peer-reviewed data on their efficacy. To determine whether treatment with a low-level laser device, the US FDA-cleared HairMax Lasercomb®, increases terminal hair density in both men and women with pattern hair loss. Randomized, sham device-controlled, double-blind clinical trials were conducted at multiple institutional and private practices. A total of 146 male and 188 female subjects with pattern hair loss were screened. A total of 128 male and 141 female subjects were randomized to receive either a lasercomb (one of three models) or a sham device in concealed sealed packets, and were treated on the whole scalp three times a week for 26 weeks. Terminal hair density of the target area was evaluated at baseline and at 16- and 26-week follow-ups, and analyzed to determine whether the hypothesis formulated prior to data collection, that lasercomb treatment would increase terminal hair density, was correct. The site investigators and the subjects remained blinded to the type of device they dispensed/received throughout the study. The evaluator of masked digital photographs was blinded to which trial arm the subject belonged. Seventy-eight, 63, 49, and 79 subjects were randomized in four trials of 9-beam lasercomb treatment in female subjects, 12-beam lasercomb treatment in female subjects, 7-beam lasercomb treatment in male subjects, and 9- and 12-beam lasercomb treatment in male subjects, compared with the sham device, respectively. Nineteen female and 25 male subjects were lost to follow-up. Among the remaining 122 female and 103 male subjects in the efficacy analysis, the mean terminal hair count at 26 weeks increased from baseline by 20.2, 20.6, 18.4, 20.9, and 25.7 per cm2 in 9-beam lasercomb-treated female subjects, 12-beam

  4. Androgens and hair growth.

    PubMed

    Randall, Valerie Anne

    2008-01-01

    Hair's importance in human communication means that abnormalities like excess hair in hirsutism or hair loss in alopecia cause psychological distress. Androgens are the main regulator of human hair follicles, changing small vellus follicles producing tiny, virtually invisible hairs into larger intermediate and terminal follicles making bigger, pigmented hairs. The response to androgens varies with the body site as it is specific to the hair follicle itself. Normally around puberty, androgens stimulate axillary and pubic hair in both sexes, plus the beard, etc. in men, while later they may also inhibit scalp hair growth causing androgenetic alopecia. Androgens act within the follicle to alter the mesenchyme-epithelial cell interactions, changing the length of time the hair is growing, the dermal papilla size and dermal papilla cell, keratinocyte and melanocyte activity. Greater understanding of the mechanisms of androgen action in follicles should improve therapies for poorly controlled hair disorders like hirsutism and alopecia.

  5. Increased Zn/Glutathione Levels and Higher Superoxide Dismutase-1 Activity as Biomarkers of Oxidative Stress in Women with Long-Term Dental Amalgam Fillings: Correlation between Mercury/Aluminium Levels (in Hair) and Antioxidant Systems in Plasma

    PubMed Central

    Cabaña-Muñoz, María Eugenia; Parmigiani-Izquierdo, José María; Bravo-González, Luis Alberto; Kyung, Hee-Moon; Merino, José Joaquín

    2015-01-01

    Background The induction of oxidative stress by Hg can affect antioxidant enzymes. However, epidemiological studies have failed to establish clear association between dental fillings presence and health problems. Objectives To determine whether heavy metals (in hair), antioxidant enzymes (SOD-1) and glutathione levels could be affected by the chronic presence of heavy metals in women who had dental amalgam fillings. Materials and Methods 55 hair samples (42 females with amalgam fillings and 13 female control subjects) were obtained. All subjects (mean age 44 years) who had dental amalgam filling for more than 10 years (average 15 years). Certain metals were quantified by ICP-MS (Mass Spectrophotometry) in hair (μg/g: Al, Hg, Ba, Ag, Sb, As, Be, Bi, Cd, Pb, Pt, Tl, Th, U, Ni, Sn, Ti) and SOD-1 and Glutathione (reduced form) levels in plasma. Data were compared with controls without amalgams, and analyzed to identify any significant relation between metals and the total number of amalgam fillings, comparing those with four or less (n = 27) with those with more than four (n = 15). As no significant differences were detected, the two groups were pooled (Amlgam; n = 42). Findings Hg, Ag, Al and Ba were higher in the amalgam group but without significant differences for most of the heavy metals analyzed. Increased SOD-1 activity and glutathione levels (reduced form) were observed in the amalgam group. Aluminum (Al) correlated with glutathione levels while Hg levels correlated with SOD-1. The observed Al/glutathione and Hg/SOD-1 correlation could be adaptive responses against the chronic presence of mercury. Conclusions Hg, Ag, Al and Ba levels increased in women who had dental amalgam fillings for long periods. Al correlated with glutathione, and Hg with SOD-1. SOD-1 may be a possible biomarker for assessing chronic Hg toxicity. PMID:26076368

  6. Increased Zn/Glutathione Levels and Higher Superoxide Dismutase-1 Activity as Biomarkers of Oxidative Stress in Women with Long-Term Dental Amalgam Fillings: Correlation between Mercury/Aluminium Levels (in Hair) and Antioxidant Systems in Plasma.

    PubMed

    Cabaña-Muñoz, María Eugenia; Parmigiani-Izquierdo, José María; Bravo-González, Luis Alberto; Kyung, Hee-Moon; Merino, José Joaquín

    2015-01-01

    The induction of oxidative stress by Hg can affect antioxidant enzymes. However, epidemiological studies have failed to establish clear association between dental fillings presence and health problems. To determine whether heavy metals (in hair), antioxidant enzymes (SOD-1) and glutathione levels could be affected by the chronic presence of heavy metals in women who had dental amalgam fillings. 55 hair samples (42 females with amalgam fillings and 13 female control subjects) were obtained. All subjects (mean age 44 years) who had dental amalgam filling for more than 10 years (average 15 years). Certain metals were quantified by ICP-MS (Mass Spectrophotometry) in hair (μg/g: Al, Hg, Ba, Ag, Sb, As, Be, Bi, Cd, Pb, Pt, Tl, Th, U, Ni, Sn, Ti) and SOD-1 and Glutathione (reduced form) levels in plasma. Data were compared with controls without amalgams, and analyzed to identify any significant relation between metals and the total number of amalgam fillings, comparing those with four or less (n = 27) with those with more than four (n = 15). As no significant differences were detected, the two groups were pooled (Amlgam; n = 42). Hg, Ag, Al and Ba were higher in the amalgam group but without significant differences for most of the heavy metals analyzed. Increased SOD-1 activity and glutathione levels (reduced form) were observed in the amalgam group. Aluminum (Al) correlated with glutathione levels while Hg levels correlated with SOD-1. The observed Al/glutathione and Hg/SOD-1 correlation could be adaptive responses against the chronic presence of mercury. Hg, Ag, Al and Ba levels increased in women who had dental amalgam fillings for long periods. Al correlated with glutathione, and Hg with SOD-1. SOD-1 may be a possible biomarker for assessing chronic Hg toxicity.

  7. The fatty acid profile of rainbow trout liver cells modulates their tolerance to methylmercury and cadmium.

    PubMed

    Ferain, Aline; Bonnineau, Chloé; Neefs, Ineke; Rees, Jean François; Larondelle, Yvan; Schamphelaere, Karel A C De; Debier, Cathy

    2016-08-01

    The polyunsaturated fatty acid (PUFA) composition of fish tissues, which generally reflects that of the diet, affects various cellular properties such as membrane structure and fluidity, energy metabolism and susceptibility to oxidative stress. Since these cellular parameters can play an important role in the cellular response to organic and inorganic pollutants, a variation of the PUFA supply might modify the toxicity induced by such xenobiotics. In this work, we investigated whether the cellular fatty acid profile has an impact on the in vitro cell sensitivity to two environmental pollutants: methylmercury and cadmium. Firstly, the fatty acid composition of the rainbow trout liver cell line RTL-W1 was modified by enriching the growth medium with either alpha-linolenic acid (ALA, 18:3n-3), eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), linoleic acid (LA, 18:2n-6), arachidonic acid (AA, 20:4n-6) or docosapentaenoic acid (DPA, 22:5n-6). These modified cells and their control (no PUFA enrichment) were then challenged for 24h with increasing concentrations of methylmercury or cadmium. We observed that (i) the phospholipid composition of the RTL-W1 cells was profoundly modulated by changing the PUFA content of the growth medium: major modifications were a high incorporation of the supplemented PUFA in the cellular phospholipids, the appearance of direct elongation and desaturation metabolites in the cellular phospholipids as well as a change in the gross phospholipid composition (PUFA and monounsaturated fatty acid (MUFA) levels and n-3/n-6 ratio); (ii) ALA, EPA and DPA enrichment significantly protected the RTL-W1 cells against both methylmercury and cadmium; (iv) DHA enrichment significantly protected the cells against cadmium but not methylmercury; (v) AA and LA enrichment had no impact on the cell tolerance to both methylmercury and cadmium; (vi) the abundance of 20:3n-6, a metabolite of the n-6 biotransformation pathway, in

  8. Expression of VEGF-related proteins in cultured human brain microvascular endothelial cells and pericytes after exposure to methylmercury.

    PubMed

    Hirooka, Takashi; Yamamoto, Chika; Yasutake, Akira; Eto, Komyo; Kaji, Toshiyuki

    2013-01-01

    The localization of neuropathological lesions along deep sulci and fissures is one of the characteristics of a cerebrum damaged by methylmercury. Edematous changes in white matter have been proposed as the cause of the localization of lesions; however, the molecular mechanisms underlying methylmercury-induced edema remain unclear. Since the vascular endothelial growth factor (VEGF) system regulates vascular permeability and can be involved in the progression of edematous changes, we examined the effect of methylmercury on the expression of VEGF-related proteins in cultured human brain microvascular endothelial cells and pericytes. After methylmercury exposure, mRNA and protein levels of VEGF-A in pericytes and placenta growth factor (PlGF) and VEGF-receptor-1/-2 in endothelial cells were elevated. The induction of pericyte VEGF-A expression was independent of hypoxia-inducible factor-α and hypoxia-response element signaling. Taken together, these results suggest that methylmercury activates the VEGF system in brain microvessels in a paracrine fashion. When the activation occurs in narrow areas such as along the deep sulci in the cerebrum, hyperpermeability and subsequent edematous changes would cause a circulatory disturbance and result in neural cell damage. We propose this as a reason for the localization of the neuropathological lesions along the deep sulci and fissures in the cerebral cortex, such as the calcarine fissure, in patients with Minamata disease.

  9. Morphine Protects against Methylmercury Intoxication: A Role for Opioid Receptors in Oxidative Stress?

    PubMed Central

    Costa-Malaquias, Allan; Almeida, Mauro B.; Souza Monteiro, José R.; Macchi, Barbarella de Matos; do Nascimento, José Luiz M.; Crespo-Lopez, María Elena

    2014-01-01

    Mercury is an extremely dangerous environmental contaminant responsible for episodes of human intoxication throughout the world. Methylmercury, the most toxic compound of this metal, mainly targets the central nervous system, accumulating preferentially in cells of glial origin and causing oxidative stress. Despite studies demonstrating the current exposure of human populations, the consequences of mercury intoxication and concomitant use of drugs targeting the central nervous system (especially drugs used in long-term treatments, such as analgesics) are completely unknown. Morphine is a major option for pain management; its global consumption more than quadrupled in the last decade. Controversially, morphine has been proposed to function in oxidative stress independent of the activation of the opioid receptors. In this work, a therapeutic concentration of morphine partially protected the cellular viability of cells from a C6 glioma cell line exposed to methylmercury. Morphine treatment also reduced lipid peroxidation and totally prevented increases in nitrite levels in those cells. A mechanistic study revealed no alteration in sulfhydryl groups or direct scavenging at this opioid concentration. Interestingly, the opioid antagonist naloxone completely eliminated the protective effect of morphine against methylmercury intoxication, pointing to opioid receptors as the major contributor to this action. Taken together, the experiments in the current study provide the first demonstration that a therapeutic concentration of morphine is able to reduce methylmercury-induced oxidative damage and cell death by activating the opioid receptors. Thus, these receptors may be a promising pharmacological target for modulating the deleterious effects of mercury intoxication. Although additional studies are necessary, our results support the clinical safety of using this opioid in methylmercury-intoxicated patients, suggesting that normal analgesic doses could confer an additional

  10. Methylmercury toxicity in spontaneously hypertensive rats (SHR)

    SciTech Connect

    Tamashiro, H.; Arakaki, M.; Akagi, H.; Hirayama, K.; Smolensky, M.H.

    1986-05-01

    Information is scant on both environmental and individual factors as potentiators of methylmercury (MeHg) toxicity in human beings and other animal species. Hypertension is quite common among the inhabitants of MeHg-polluted areas. It is of special interest to learn what is the health consequence among the hypertensives who have been exposed to MeHg for a prolonged period of time. This study was designed to delineate the toxicity of MeHg in animals having high blood pressure using the laboratory model of spontaneously hypertensive rats (SHR). This paper presents the mortality as well as distribution of mercury in the tissues of SHR and control rats treated orally with methylmercury chloride for 10 consecutive days.

  11. Understanding arsenic metabolism through a comparative study of arsenic levels in the urine, hair and fingernails of healthy volunteers from three unexposed ethnic groups in the United Kingdom

    SciTech Connect

    Brima, Eid I.; Haris, Parvez I. . E-mail: pharis@dmu.ac.uk; Jenkins, Richard O.; Polya, Dave A.; Gault, Andrew G.; Harrington, Chris F.

    2006-10-01

    Very little is known about arsenic (As) metabolism in healthy populations that are not exposed to high concentrations of As in their food or water. Here we present a study with healthy volunteers from three different ethnic groups, residing in Leicester, UK, which reveals statistically significant differences in the levels of total As in urine and fingernail samples. Urine (n = 63), hair (n = 36) and fingernail (n = 36) samples from Asians, Somali Black-Africans and Whites were analysed using inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectroscopy (GF-AAS). The results clearly show that the total concentrations of As in urine and fingernail samples of a Somali Black-African population (urine 7.2 {mu}g/g creatinine; fingernails 723.1 {mu}g/kg) are significantly (P < 0.05) different from the Asian (urine 24.5 {mu}g/g creatinine; fingernails 153.9 {mu}g/kg) and White groups (urine 20.9 {mu}g/g creatinine; fingernails 177.0 {mu}g/kg). The chemical speciation of As in the urine of the three groups was also measured using high performance liquid chromatography coupled to ICP-MS. This showed that the proportion of the total urinary As present as dimethylarsenate (DMA) was higher for the Somali Black-African group (50%) compared to the Asians (16%) and Whites (22%). However, there was no significant difference (P > 0.05) in the level of As in the hair samples from these three groups; Somali Black-Africans (116.0 {mu}g/kg), Asians (117.4 {mu}g/kg) and Whites (141.2 {mu}g/kg). Significantly different levels of total As in fingernail and urine and a higher percentage of urinary DMA in the Somali Black-Africans are suggestive of a different pattern of As metabolism in this ethnic group.

  12. High levels of hair manganese in children living in the vicinity of a ferro-manganese alloy production plant.

    PubMed

    Menezes-Filho, José A; Paes, Ciro R; Pontes, Angela M de C; Moreira, Josino C; Sarcinelli, Paula N; Mergler, Donna

    2009-11-01

    Manganese (Mn) is an essential element, but an effective toxic at high concentrations. While there is an extensive literature on occupational exposure, few studies have examined adults and children living near important sources of airborne Mn. The objective of this study was to analyze hair Mn of children living in the vicinity of a ferro-manganese alloy production plant in the Great Salvador region, State of Bahia, Brazil and examine factors that influence this bioindicator of exposure. We examined 109 children in the age range of 1-10 years, living near the plant. Four separate housing areas were identified a priori on the bases of proximity to the emission sources and downwind location. A non-exposed group (n=43) of similar socio-economic status was also evaluated. Mn hair (MnH) concentration was measured by graphite atomic absorption spectrometry (GFAAS). Possible confounding hematological parameters were also assessed. Mean MnH concentration was 15.20 microg/g (1.10-95.50 microg/g) for the exposed children and 1.37 microg/g (0.39-5.58 microg/g) for the non-exposed. For the former, MnH concentrations were 7.95+/-1.40 microg/g (farthest from the plant), 11.81+/-1.11 microg/g (mid-region), 34.43+/-8.66 microg/g (closest to the plant) and 34.22+/-9.15 microg/g (directly downwind). Multiple regression analysis on log transformed MnH concentrations for the exposed children derived a model that explained 36.8% of the variability. In order of importance, area of children's residence, gender (girls>boys) and time of mother's residence in the area at the birth of the child, were significantly associated with MnH. Post hoc analyses indicated two groupings for exposure areas, with those living closest to and downwind of the plant displaying higher MnH concentrations compared to the others. The contribution of the time the mother lived in the community prior to the child's birth to the children's current MnH suggests that in utero exposure may play a role. A study of

  13. HIGH LEVELS OF HAIR MANGANESE IN CHILDREN LIVING IN THE VICINITY OF A FERRO-MANGANESE ALLOY PRODUCTION PLANT

    PubMed Central

    Menezes-Filho, José A.; Paes, Ciro R.; de C. Pontes, Ângela M.; Moreira, Josino C.; Sarcinelli, Paula N.; Mergler, Donna

    2009-01-01

    Manganese (Mn) is an essential element, but an effective toxic at high concentrations. While there is an extensive literature on occupational exposure, few studies have examined adults and children living near important sources of airborne Mn. The objective of this study was to analyze hair Mn of children living in the vicinity of a ferro-manganese alloy production plant in the Great Salvador region, State of Bahia, Brazil and examine factors that influence this bioindicator of exposure. We examined 109 children in the age range of 1 to 10 years, living near the plant. Four separate housing areas were identified a priori on the bases of proximity to the emission sources and downwind location. A non-exposed group (n=43) of similar socioeconomic status was also evaluated. Mn hair (MnH) concentration was measured by graphite atomic absorption spectrometry (GFAAS). Possible confounding hematological parameters were also assessed. Mean MnH concentration was 15.20 μg/g (1.10–95.50 μg/g) for the exposed children and 1.37 μg/g (0.39–5.58 μg/g) for the non-exposed. For the former, MnH concentrations were 7.95±1.40 μg/g (farthest from the plant), 11.81±1.11 μg/g (mid-region), 34.43±8.66 μg/g (closest to the plant) and 34.22±9.15 μg/g (directly downwind). Multiple regression analysis on log transformed MnH concentrations for the exposed children derived a model that explained 36.8% of the variability. In order of importance, area of children’s residence, gender (girls > boys) and time of mother’s residence in the area at the birth of the child, were significantly associated with MnH. Post hoc analyses indicated 2 groupings for exposure areas, with those living closest to and downwind of the plant displaying higher MnH concentrations compared to the others. The contribution of the time the mother lived in the community prior to the child’s birth to the children’s current MnH suggests that in utero exposure may play a role. A study of neurobehavioral

  14. Female Pattern Hair Loss

    MedlinePlus

    ... Category: Share: Yes No, Keep Private Female Pattern Hair Loss Share | The most common type of hair loss seen in women is androgenetic alopecia, also ... men, it does not have to be complete hair loss. This is seen as hair thinning predominantly ...

  15. Hair loss in women.

    PubMed

    Tosti, A; Piraccini, B M; Sisti, A; Duque-Estrada, B

    2009-10-01

    Hair loss in women is a very common clinical complaint, and is usually associated with severe emotional distress. In this article, the authors review the most common clinical causes of hair loss in women, and emphasize the role of hormonal changes in the regulation of hair loss and hair growth.

  16. What is a Caucasian 'fine' hair? Comparing instrumental measurements, self-perceptions and assessments from hair experts.

    PubMed

    Bouabbache, S; Galliano, A; Littaye, P; Leportier, M; Pouradier, F; Gillot, E; Panhard, S; Loussouarn, G

    2016-12-01

    To determine the various factors contributing to what Caucasian women describe as 'fine hair'. Three complementary approaches were used, namely self-evaluation by the volunteer, assessment by a sensorial expert and instrumental measurements, in order to determine some of the possible parameters taken into account by Caucasian women when they describe the notion of fine hair. One hundred fifty one women of Caucasian origin participated in the study. They varied in age, and varied in that some considered themselves as having fine hair, and others not. The instrumental measurements carried out included hair diameter measurements, hair density measurements, hair breakage force, hair flexibility and scalp sebum levels. From six parameters defined initially, four parameters were found to be in common with the three approaches: hair abundance (density), hair thickness, hair resistance and the volume of the hair on the head. The commonly used term 'body' was only common to self and expert evaluation, whereas the influence of curliness was only common to expert evaluation and instrumental measurements. This study has shown close agreement between sensorial and instrumental findings, and also illustrates how the women participating can subtly and adequately describe their own hair. It is important to note that the words 'fine hair' describes a lot more than just physically thin hair fibres. Ageing is an additional factor that clearly impacts certain parameters associated with 'fine hair' among the volunteers. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  17. What has methylmercury in umbilical cords told us? - Minamata disease.

    PubMed

    Yorifuji, Takashi; Kashima, Saori; Tsuda, Toshihide; Harada, Masazumi

    2009-12-20

    Severe methylmercury poisoning occurred in Minamata and neighboring communities in the 1950s and 1960s. The exposed patients manifested neurological signs, and some patients exposed in utero were born with so-called congenital Minamata disease. In a previous report, Nishigaki and Harada evaluated the methylmercury concentrations in the umbilical cords of inhabitants and demonstrated that methylmercury actually passed through the placenta (Nishigaki and Harada, 1975). However, the report involved a limited number of cases (only 35) and did not quantitatively evaluate the regional differences in the transition of methylmercury exposure. Therefore, in the present study, we evaluated the temporal and spatial distributions of methylmercury concentrations in umbilical cords, with an increased number of participants and additional descriptive analyses. Then, we examined whether the methylmercury concentrations corresponded with the history of the Minamata disease incident. A total of 278 umbilical cord specimens collected after birth were obtained from babies born between 1925 and 1980 in four study areas exposed to methylmercury. Then, we conducted descriptive analyses, and drew scatterplots of the methylmercury concentrations of all the participants and separated by the areas. In the Minamata area, where the first patient was identified in 1956, the methylmercury concentration reached a peak around 1955. Subsequently, about 5 years later, the concentrations peaked in other exposed areas with the expected exposure distribution corresponding with acetaldehyde production (the origin of methylmercury). This historical incident several decades ago in Minamata and neighboring communities clearly shows that regional pollution affected the environment in utero. Furthermore, the temporal and spatial distributions of the methylmercury concentrations in the umbilical cords tell us the history of the Minamata disease incident.

  18. Cognitive deficits at age 22 years associated with prenatal exposure to methylmercury

    PubMed Central

    Debes, Frodi; Weihe, Pal; Grandjean, Philippe

    2015-01-01

    Prenatal exposure to mercury has been associated with adverse effects on child neurodevelopment. The present study aims to determine the extent to which methylmercury-associated cognitive deficits persist into adult age. In a Faroese birth cohort originally formed in 1986–1987 (N=1,022), prenatal methylmercury exposure was assessed in terms of the mercury concentration in cord blood and maternal hair. Clinical examinations of 847 cohort members at age 22 years were carried out in 2008–2009 using a panel of neuropsychological tests that reflected major functional domains. Subjects with neurological and psychiatric diagnoses were excluded from the data analysis, thus leaving 814 subjects. Multiple regression analysis included covariates previously identified for adjustment. Deficits in Boston Naming Test and other tests of verbal performance were significantly associated with the cord-blood mercury concentration. Deficits were also present in all other tests applied, although most were not statistically significant. Structural equation models were developed to ascertain the possible differences in vulnerability of specific functional domains and the overall association with general intelligence. In models for individual domains, all of them showed negative associations, with crystallized intelligence being highly significant. A hierarchical model for general intelligence based on all domains again showed a highly significant negative association with the exposure, with an approximate deficit that corresponds to about 2.2 IQ points at a 10-fold increased prenatal methylmercury exposure. Thus, although the cognitive deficits observed were smaller than at examinations at younger ages, maternal seafood diets were associated with adverse effects in this birth cohort at age 22 years. The deficits affected major domains of brain functions as well as general intelligence. Thus, prenatal exposure to this marine contaminant appears to cause permanent adverse effects on

  19. [Usefulness of umbilical cord mercury concentrations as biomarkers of fetal exposure to methylmercury].

    PubMed

    Murata, Katsuyuki; Dakeishi, Miwako; Shimada, Miyuki; Satoh, Hiroshi

    2007-09-01

    In epidemiological studies on the health effect of methylmercury (MeHg) exposure, maternal-hair mercury concentration has been used as an exposure biomarker because of its ease of collection and capability to recapture the exposure history. However, artificial hair-waving reduces the mercury concentration and there is little agreement about which part of the hair strand properly represents fetal exposure. We presented an overview of the studies addressing umbilical cord and mercury in PubMed and evaluated the usefulness of umbilical cord mercury concentrations as biomarkers of fetal exposure to MeHg. The mean total mercury (T-Hg) concentration in cord blood was between 0.5 and 35.6microg/l, and the cord blood-to-maternal blood ratio of T-Hg concentrations was estimated to be approximately 1.5. MeHg concentrations in dried cord tissue did not exceed 0.4 microg/g in Japanese populations without particular exposure to MeHg. Dried cord tissue appeared to be better than wet tissue because the definition of wet weight of the umbilical cord is ambiguous. Both cord-blood and cord-tissue mercury concentrations seemed to correlate closely with maternal-hair and maternal-blood ones. Since cord mercury concentrations are a direct exposure biomarker of the fetus and the cord blood-to-maternal blood ratio of mercury differed markedly among mother-child pairs, mercury concentration in cord blood or dried cord tissue should therefore be used in assessing the possible effects of fetal exposure to MeHg on the susceptible brain. Further studies are required to clarify at which period of exposure during gestation the cord mercury concentration represents in relation to mercury concentrations in maternal segmental hair.

  20. Hair Cosmetics: An Overview

    PubMed Central

    Gavazzoni Dias, Maria Fernanda Reis

    2015-01-01

    Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity. PMID:25878443

  1. Microscopic hair changes associated with hair coloring, hair waving and hair ironing in Iranian women.

    PubMed

    Talghini, Shahla; Ranjkesh, Mohammadreza

    2013-10-15

    Although, of no vital value, hair plays a significant role in expressing any person's psychosocial status. Many cosmetic and styling methods are available for hair. This study aimed to examine the microscopic changes in women with hair coloring, hair waving, or hair ironing in comparison with normal controls. In a cross-sectional study, 154 Iranian women were recruited and categorized in 4 groups: controls (n = 35) who had not dyed, waved or ironed their hair within the last 6 months; dyed-hair group (n = 49) who had dyed their hair using standard chemical hair colors at least three times within the last 6 months; waved-hair group (n = 35) who had frizzled their hair within the last 6 months and ironed-hair group (n = 35) who had ironed their hair at least 3 times a weak using a temperature more than 30 degrees C within the last 6 months. Hair samples of all four groups were examined microscopically, and the results were compared with the controls. The rate of abnormal findings was 17.1% in the controls, 53.1% in the dyed-hair group, 45.7% in the waved-hair group, and 54.3% in the ironed-hair group. Abnormal findings were significantly more frequent in the last three groups comparing with the controls (p < 0.05). Trichorrhexis was 17.1, 34.7, 40 and 11.4%; kinking was 0, 2, 2.9 and 25.7%; pseudo pili-annulati was 0, 6.1, 0 and 17.1%; trichonodosis was 0, 6.1, 0 and 0%; tracheoschises was 0, 2, 2.9 and 0% and trichoptilosis was 0, 2, 0 and 0% in the mentioned groups, respectively. Based on the results of the present study, hair coloring, waving and ironing all can induce abnormalities in the hair in comparison with the hairs of nonusers.

  2. Hair loss in women.

    PubMed

    Harfmann, Katya L; Bechtel, Mark A

    2015-03-01

    Hair loss is a common cause of morbidity for many women. As a key member of the woman's health care team, the obstetrician/gynecologist may be the first person to evaluate the complaint of hair loss. Common types of nonscarring hair loss, including female pattern hair loss and telogen effluvium, may be diagnosed and managed by the obstetrician/gynecologist. A systematic approach to diagnosis and management of these common forms of hair loss is presented.

  3. [Hair and their environment].

    PubMed

    Piérard-Franchimont, C; Piérard, G E

    2015-02-01

    Hair is influenced by the effects of the daily environment. Some toxic xenobiotics slow down or block the cell renewal of the hair matrix, thus inhibiting hair growth. The ultraviolet light obviously influences the physical structure and physiology of the hair follicle. Tobacco is similarly responsible for negative influences on the evolution of various alopecias. Several cosmetic procedures for maintaining and making hair more attractive are not always harmless, and they occasionally represent a possible origin for alopecia.

  4. Trace metal ions in hair from frequent hair dyers in China and the associated effects on photo-oxidative damage.

    PubMed

    Tang, Ying; Dyer, Jolon M; Deb-Choudhury, Santanu; Li, Qiao

    2016-03-01

    Human hairs are subject to oxidative modification when exposed to sunlight. In the present study, samples of human hair from Chinese volunteers that included frequent hair dyers and non-dyers were analyzed for metal ions such as iron, copper, magnesium, aluminum, zinc and lead. The generation of hydroxyl radicals during UVA (315-400 nm) photoageing was quantified and oxidative damages characterized by proteomic and SEM analysis. It was concluded that high levels of metal ions, particularly those derived from iron and copper, identified in the dyed hairs are associated with enhanced photoformation of hydroxyl radicals and resultant photooxidative damage of the hair. Reactive oxygen species, including hydroxyl radicals, generated via an electron transfer mechanism with hair photosensitizers react with hair proteins. Proteomic analysis of hair samples from frequent hair dyers, regardless of age and gender, showed an almost 1.6 fold increase in the protein oxidative modification levels compared to the undyed samples. As a result, a more pronounced physical damage including fragmentation and cross-linkage of cuticle scales was observed on the surface of dyed hair samples during the photoageing. This work is aimed at better understanding the role of metal ions in dyed hairs and their possible role in photosensitizing hair proteins. The results from this study are anticipated to contribute to the improved development of hair coloring cosmetics and hair care products.

  5. Aging of hair.

    PubMed

    Trüeb, Ralph M

    2005-06-01

    The appearance of hair plays an important role in people's overall physical appearance and self-perception. With today's increasing life expectation, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and also more capable to deliver active products that are directed toward meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft and aging of the hair follicle. The latter manifests as decrease of melanocyte function or graying, and decrease in hair production in androgenetic and senescent alopecia. The scalp is also subject to intrinsic or physiologic aging and extrinsic aging caused by external factors. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation. Prototypes are familial premature graying and androgenetic alopecia. Extrinsic factors include ultraviolet radiation and smoking. Experimental evidence supports the hypothesis that oxidative stress plays a role in skin and hair aging. Topical anti-aging compounds for hair include humefactants, hair conditioners, photoprotectors, and antioxidants. Current available treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil, oral finasteride, and autologous hair transplantation. In the absence of another way to reverse hair graying, hair colorants are the mainstays of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are under current investigation.

  6. Methylmercury Poisoning—An Assessment of the Sportfish Hazard in California

    PubMed Central

    Dales, Loring; Kahn, Ephraim; Wei, Eddie

    1971-01-01

    A quantitative assessment of the methylmercury risk in California entails measurement of the contamination distribution, the probability of methylmercury intake and knowledge of the toxicological properties of methylmercury. This article reviews the scientific basis for the California State Task Force's decision to warn the public against excessive consumption of sport fish contaminated by methylmercury. PMID:5544687

  7. Splitting hair for cortisol? Associations of socio-economic status, ethnicity, hair color, gender and other child characteristics with hair cortisol and cortisone.

    PubMed

    Rippe, Ralph C A; Noppe, Gerard; Windhorst, Dafna A; Tiemeier, Henning; van Rossum, Elisabeth F C; Jaddoe, Vincent W V; Verhulst, Frank C; Bakermans-Kranenburg, Marian J; van IJzendoorn, Marinus H; van den Akker, Erica L T

    2016-04-01

    The aim of this study was to examine associations of SES and ethnicity with hair cortisol and cortisone and to identify potential child and family characteristics that can assist in choosing covariates and potential confounders for analyses involving hair cortisol and cortisone concentrations. Hair samples were collected in 2484 6-year-old children from the Generation R Study, a prospective cohort in Rotterdam, the Netherlands. Measurements for cortisol and cortisone were used as the outcome in regression analyses. Predictors were SES, ethnicity, hair color and child characteristics such as birthweight, gestational age at birth, BMI, disease, allergy, and medication use. Lower family income, more children to be supported by this income, higher BMI and darker hair color were associated with higher hair cortisol and cortisone levels. Boys also showed higher levels. Ethnicity (Dutch and North European descent) was related to lower levels. High amounts of sun in the month of hair collection was related to higher levels of cortisone only. More recent hair washing was related to lower levels of cortisol and cortisone. Gestational age at birth, birth weight, age, medication use, hair washing frequency, educational level of the mother, marital status of the mother, disease and allergy were not associated with cortisol or cortisone levels. Our results serve as a starting point for choosing covariates and confounders in studies of substantive predictors or outcomes. Gender, BMI, income, the number of persons in a household, ethnicity, hair color and recency of hair washing are strongly suggested to take into account.

  8. Development of adrenergic receptor binding sites in brain regions of the neonatal rat: effects of prenatal or postnatal exposure to methylmercury

    SciTech Connect

    Bartolome, J.V.; Kavlock, R.J.; Cowdery, T.; Orband-Miller, L.; Slotkin, T.A.

    1987-01-01

    In order to understand the effects of developmental exposure to methylmercury on the ontogeny of synaptic function, the impact of prenatal or postnatal exposure on acquisition of receptor binding sites for norepinephrine was examined. The actions of the mercurial were both regionally - and receptor subtype-selective and depended upon the maturational profile of each region. Alpha 1 and alpha 2 and Beta-receptor sites in the cerebellum, the region which develops last, were the most vulnerable to methylmercury. In contrast, the same receptor subtypes in the midbrain + brainstem, which develops earliest, were resistant to methylmercury. The cerebal cortex, which matures at a time midway between cerebellum and midbrain + brainstem, also displayed intermediate vulnerability to actions of methylmercury on receptors. Within the cerebellum, prenatal exposure to 1 mg/kg to methylmercury, interfered the most with ontogeny of alpha 1-receptor binding, less so far alpha 2-receptors and least for Beta-receptors. Lower doses of methylmercury tended to increase receptor binding for all subtypes, a fact which may contribute to promotion of neurological development seen in animals exposed to those levels.

  9. A case report of motor neuron disease in a patient showing significant level of DDTs, HCHs and organophosphate metabolites in hair as well as levels of hexane and toluene in blood

    SciTech Connect

    Kanavouras, Konstantinos; Tzatzarakis, Manolis N.; Mastorodemos, Vasileios; Plaitakis, Andreas; Tsatsakis, Aristidis M.

    2011-11-15

    Motor neuron disease is a devastating neurodegenerative condition, with the majority of sporadic, non-familial cases being of unknown etiology. Several epidemiological studies have suggested that occupational exposure to chemicals may be associated with disease pathogenesis. We report the case of a patient developing progressive motor neuron disease, who was chronically exposed to pesticides and organic solvents. The patient presented with leg spasticity and developed gradually clinical signs suggestive of amyotrophic lateral sclerosis, which was supported by the neurophysiologic and radiological findings. Our report is an evidence based case of combined exposure to organochlorine (DDTs), organophosphate pesticides (OPs) and organic solvents as confirmed by laboratory analysis in samples of blood and hair confirming systematic exposure. The concentration of non-specific dialkylphosphates metabolites (DAPs) of OPs in hair (dimethyphopshate (DMP) 1289.4 pg/mg and diethylphosphate (DEP) 709.4 pg/mg) and of DDTs (opDDE 484.0 pg/mg, ppDDE 526.6 pg/mg, opDDD 448.4 pg/mg, ppDDD + opDDT 259.9 pg/mg and ppDDT 573.7 pg/mg) were considerably significant. Toluene and n-hexane were also detected in blood on admission at hospital and quantified (1.23 and 0.87 {mu}g/l, respectively), while 3 months after hospitalization blood testing was found negative for toluene and n-hexane and hair analysis was provided decrease levels of HCHs, DDTs and DAPs. -- Highlights: Black-Right-Pointing-Pointer Exposure to pesticides and organic solvents might be a risk factor for sporadic MND. Black-Right-Pointing-Pointer We report a patient who developed progressive upper and lower motor neuron disease. Black-Right-Pointing-Pointer The patient had a history of occupational exposure to pesticides and solvents. Black-Right-Pointing-Pointer High DDTs' levels and increased levels of DMP and DEP were measured in his hair. Black-Right-Pointing-Pointer The patients' exposure to chemicals might have played

  10. New trichoscopy findings in trichotillomania: flame hairs, V-sign, hook hairs, hair powder, tulip hairs.

    PubMed

    Rakowska, Adriana; Slowinska, Monika; Olszewska, Malgorzata; Rudnicka, Lidia

    2014-05-01

    Differential diagnosis of trichotillomania is often difficult in clinical practice. Trichoscopy (hair and scalp dermoscopy) effectively supports differential diagnosis of various hair and scalp diseases. The aim of this study was to assess the usefulness of trichoscopy in diagnosing trichotillomania. The study included 370 patients (44 with trichotillomania, 314 with alopecia areata and 12 with tinea capitis). Statistical analysis revealed that the main and most characteristic trichoscopic findings of trichotillomania are: irregularly broken hairs (44/44; 100% of patients), v-sign (24/44; 57%), flame hairs (11/44; 25%), hair powder (7/44; 16%) and coiled hairs (17/44; 39%). Flame hairs, v-sign, tulip hairs, and hair powder were newly identified in this study. In conclusion, we describe here specific trichoscopy features, which may be applied in quick, non-invasive, in-office differential diagnosis of trichotillomania.

  11. Neurotoxicity of lead, methylmercury, and PCBs in relation to the Great Lakes.

    PubMed Central

    Rice, D C

    1995-01-01

    There is ample evidence identifying lead, methylmercury, and polychlorinated biphenyls (PCBs) as neurotoxic agents. A large body of data on the neurotoxicity of lead, based on both epidemiologic studies in children and animal models of developmental exposure, reveals that body burdens of lead typical of people in industrialized environments produce behavioral impairment. Methylmercury was identified as a neurotoxicant in both adults and the developing organism based on episodes of human poisoning: these effects have been replicated and extended in animals. High-dose PCB exposure was recognized as a developmental toxicant as a result of several episodes of contamination of cooking oil. The threshold for PCB neurotoxicity in humans is less clear, although research in animals suggests that relatively low-level exposure produces behavioral impairment and other toxic effects. Tissue levels in fish below which human health would not be adversely affected were estimated for methylmercury and PCBs based on calculated reference doses (RfDs) and estimated fish intake. Present levels in fish tissue in the Great Lakes exceed these levels for both neurotoxicants. Great Lakes fish and water do not pose a particular hazard for increased lead intake. However, the fact that the present human body burden is in a range at which functional deficits are probable suggests that efforts should be made to eliminate point sources of lead contamination in the Great Lakes basin. PMID:8635443

  12. Chemical processing and shampooing impact cortisol measured in human hair.

    PubMed

    Hoffman, M Camille; Karban, Laura V; Benitez, Patrick; Goodteacher, Angela; Laudenslager, Mark L

    2014-08-01

    The assessment of cortisol in hair has gained popularity as a means to measure retrospective hypothalamic-pituitary-adrenal activity in a number of species; however, cortisol levels from human hair subjected to typical chemicals for cosmetic or hygienic purposes may be altered by the chemicals used. The purposed of this study was to determine if exposure of hair to chemical processing or shampooing impacts cortisol values. Human hair not exposed to prior chemical processing was cut from the posterior vertex region of the head of 106 human subjects as close to the scalp as possible. The hair sample was divided into 4-6 full-length clusters depending on quantity of hair available. Each hair sample was processed for baseline (native) cortisol and remaining clusters were exposed to five standard chemical hair treatments (Experiment 1) or were shampooed 15 or 30 times (Experiment 2). Hair was ground and cortisol levels were determined by enzyme immunoassay (EIA). Comparisons were made between native hair and processed hair using paired t-tests and Pearson correlation. Hair cortisol as assessed by EIA was significantly altered by chemical processing but in somewhat different ways. Exposure to bleach (harshest exposure), demi-perm (least exposure) or 15-30 shampoos resulted in a significant decrease in cortisol level while exposure to varying percentages of peroxides increased cortisol measured. There were no differences in cortisol levels associated with sex, age or tobacco use in the native hair for this particular group. Chemical processing and frequent shampooing affect cortisol levels measured in hair. Chemically processed or excessively shampooed hair should be avoided when recruiting subjects for hair cortisol studies.

  13. Chemical processing and shampooing impact cortisol measured in human hair

    PubMed Central

    Hoffman, M. Camille; Karban, Laura V.; Benitez, Patrick; Goodteacher, Angela; Laudenslager, Mark L.

    2015-01-01

    Purpose The assessment of cortisol in hair has gained popularity as a means to measure retrospective hypothalamic-pituitary-adrenal activity in a number of species; however, cortisol levels from human hair subjected to typical chemicals for cosmetic or hygienic purposes may be altered by the chemicals used. The purposed of this study was to determine if exposure of hair to chemical processing or shampooing impacts cortisol values. Methods Human hair not exposed to prior chemical processing was cut from the posterior vertex region of the head of 106 human subjects as close to the scalp as possible. The hair sample was divided into 4-6 full-length clusters depending on quantity of hair available. Each hair sample was processed for baseline (native) cortisol and remaining clusters were exposed to five standard chemical hair treatments (Experiment 1) or were shampooed 15 or 30 times (Experiment 2). Hair was ground and cortisol levels were determined by enzyme immunoassay (EIA). Comparisons were made between native hair and processed hair using paired t-tests and Pearson correlation. Results Hair cortisol as assessed by EIA was significantly altered by chemical processing but in somewhat different ways. Exposure to bleach (harshest exposure), demi-perm (least exposure) or 15-30 shampoos resulted in a significant decrease in cortisol level while exposure to varying percentages of peroxides increased cortisol measured. There were no differences in cortisol levels associated with sex, age or tobacco use in the native hair for this particular group. Conclusion Chemical processing and frequent shampooing affect cortisol levels measured in hair. Chemically processed or excessively shampooed hair should be avoided when recruiting subjects for hair cortisol studies. PMID:25090265

  14. Beam shaping for cosmetic hair removal

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.; Tuttle, Tracie

    2007-09-01

    Beam shaping has the potential to provide comfort to people who require or seek laser based cosmetic skin procedures. Of immediate interest is the procedure of aesthetic hair removal. Hair removal is performed using a variety of wavelengths from 480 to 1200 nm by means of filtered Xenon flash lamps (pulsed light) or 810 nm diode lasers. These wavelengths are considered the most efficient means available for hair removal applications, but current systems use simple reflector designs and plane filter windows to direct the light to the surface being exposed. Laser hair removal is achieved when these wavelengths at sufficient energy levels are applied to the epidermis. The laser energy is absorbed by the melanin (pigment) in the hair and hair follicle which in turn is transformed into heat. This heat creates the coagulation process, which causes the removal of the hair and prevents growth of new hair [1]. This paper outlines a technique of beam shaping that can be applied to a non-contact based hair removal system. Several features of the beam shaping technique including beam uniformity and heat dispersion across its operational treatment area will be analyzed. A beam shaper design and its fundamental testing will be discussed in detail.

  15. Poor psychometric scores of children living in isolated riverine and agrarian communities and fish-methylmercury exposure.

    PubMed

    Fonseca, Márlon de F; Dórea, José G; Bastos, Wanderley R; Marques, Rejane C; Torres, João P M; Malm, Olaf

    2008-11-01

    Because of heavy dependence on fish, Amazonian riparian communities are chronically exposed to high levels of methylmercury (MeHg). We studied fish-MeHg exposure (total hair-Hg, HHg) as a determinant of neurocognitive scores of children living in two geographically distant, culturally distinct and isolated poor communities of non-urban environments: Amazonian riverines (Riparians, n=38) of the Puruzinho Lake community in the Rio Madeira Basin and rural agrarians from Iúna, Espírito Santo (Agrarians, n=32). Nutritional status was estimated by anthropometry (Z-scores) and individual cognitive abilities were assessed by the Wechsler Intelligence Scale for Children-III (WISC-III) and the Human Figure Drawings (HFD), both validated versions for Brazilian children. Anthropometric assessment showed slightly elevated Z-scores for the Agrarian children (not statistically significant) but median HHg concentrations were 14.4 and 0.25microgg(-1) respectively for Riparian and Agrarian children (p=0.000). Despite paradoxical MeHg exposures, both groups showed comparable HFD scores but very poor performance in WISC-III test battery; median of sum of WISC-III subtests scores (SigmaTOT) were 17.9 and 28.6 (p<0.000) for Riparian and Agrarian children, respectively (percentage scale). Spearman correlation between nutritional status (attained growth) and psychometric scores were statistically significant between height-for-age Z-score and Object Assembly subtest (r=0.269; p=0.043), SigmaTOT (r=0.319; p=0.016), Performance-IQ (r=0.311; p=0.019) and Perceptual Organization Index scores (r=0.302; p=0.023). In these isolated communities there are stronger determinants of neurocognitive poor performance than MeHg exposure. Global strategies for reducing human exposure to MeHg by curtailing fish consumption are unrealistic options for riverine subsistence populations and are not justifiable to prevent low cognitive scores.

  16. Integral hair lipid in human hair follicle.

    PubMed

    Lee, Won-Soo

    2011-12-01

    Integral hair lipid (IHL) is bound to the keratinized cell surface to make an environmentally resistant lipid envelope. It is mainly positioned on the hair cuticle and inner root sheath. IHL in the hair follicle may regard as hair barrier to be similar to the epidermal lipid layer functioning as skin barrier. Major constituents of IHL are fatty acid, phytosphingosine, ceramide in decreasing order. Minor constituents of IHL are cholesterol, cholesterol sulfate and cholesterol oleate. Cuticle or cortical cell surface in hair are abundant in fatty acids unlike the keratinized area of epidermis or sebaceous gland, and about 30-40% of such fatty acids are composed of 18-methyl-eicosanoic acid which is known to be bound to proteins by ester or thioester bond. Various factors including moisture, solvent, oxidative damage during bleaching or permanent waving affect IHL. Photochemical changes also can occur in IHL as well as in hair protein and hair pigment. Lipid metabolism is thought to play an essential role in lipid envelope of hair, but also involvement in hair development and function. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  17. Digestibility of Buffel grass (Cenchrus ciliaris)-based diets supplemented with four levels of Gliricidia sepium hay in hair sheep lambs.

    PubMed

    Avilés-Nieto, Jonathan N; Valle-Cerdán, José L; Castrejón-Pineda, Francisco; Angeles-Campos, Sergio; Vargas-Bello-Pérez, Einar

    2013-08-01

    The objective of this experiment was to evaluate the effect of supplementing increasing levels of Gliricidia sepium hay (GS) with different levels of inclusion of Buffel grass (BG) hay on digestibility by hair sheep lambs (2.5 to 3.5 months of age). Eight male lambs were used in a replicated 4 × 4 Latin square design with 21-day experimental periods (n = 4). Animals were fed with BG with different levels of GS: 100% BG (T1, control), 90% BG + 10% GS (T2), 80% BG + 20% GS (T3), and 70% BG + 30% GS (T4). Dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) intakes were not affected by treatments. The intake of crude protein (CP), organic matter (OM), and gross energy was higher (P < 0.05) in those lambs fed with T4 diet than control. NDF and ADF digestibilities were higher (P < 0.05) in T1 than in the other treatments. CP digestibility was higher (P < 0.05) in T4 compared to T1, T2, and T3. The study showed that inclusion of GS up to 30% with BG in forage-based diets of sheep does not affect DM and fiber intake nor influence DM and OM digestibilities but it increases CP intake and reduces NDF and ADF digestibilities.

  18. Potentiation of Methylmercury-Induced Death in Rat Cerebellar Granular Neurons Occurs by Further Decrease of Total Intracellular GSH with BDNF via TrkB in Vitro.

    PubMed

    Sakaue, Motoharu; Maki, Takehiro; Kaneko, Takuya; Hemmi, Natsuko; Sekiguchi, Hitomi; Horio, Tomoyo; Kadowaki, Erina; Ozawa, Aisa; Yamamoto, Masako

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) is a principal factor for neurogenesis, neurodevelopment and neural survival through a BDNF receptor, tropomyosin-related kinase (Trk) B, while BDNF can also cause a decrease in the intracellular glutathione (GSH) level. We investigated the exacerbation of methylmercury-induced death of rat cerebellar granular neurons (CGNs) by BDNF in vitro. Since methylmercury can decrease intracellular GSH levels, we hypothesized that a further decrease of the intracellular GSH level is involved in the process of the exacerbation of neuronal cell death. In the present study, we established that in CGN culture, a decrease of the intracellular GSH level was further potentiated with BDNF in the process of the methylmercury-induced neuronal death and also in GSH reducer-induced neuronal death. BDNF treatment promoted the decrease in GSH levels induced by methylmercury and also by L-buthionine sulfoximine (BSO) and diethyl maleate (DEM). The promoting effect of BDNF was observed in a TrkB-vector transformant of the rat neuroblastoma B35 cell line but not in the mock-vector transformant. These results indicate that the exacerbating effect of BDNF on methylmercury-induced neuronal death in cultures of CGNs includes a further decrease of intracellular GSH levels, for which TrkB is essential.

  19. The many faces of methylmercury poisoning

    SciTech Connect

    Elhassani, S.B.

    1982-10-01

    Methylmercury (MM) is a very potent neurotoxic agent. Its role in polluting the environment is well documented. A vast amount of study over the past several decades has finally provided insight into many aspects of its effect. Exposure to MM may be through ingestion of poisoned fish or inadvertent misuse of grain treated with the poison as a fungicide. Major epidemics have occurred in Japan (Fetal Minamata disease), Iraq, Pakistan, Guatemala, and Ghana. Sporadic incidences have occurred in the United States and Canada. There is no effective antidote to counteract the effect of MM on the central nervous system, although the information documented should provide hope for more effective therapy in acute cases.

  20. Reproduction in mallards exposed to dietary concentrations of methylmercury.

    PubMed

    Heinz, Gary H; Hoffman, David J; Klimstra, Jon D; Stebbins, Katherine R

    2010-06-01

    The purpose of this experiment was to use mallards (Anas platyrhynchos) tested under controlled conditions to determine how much harm to reproduction resulted from various concentrations of mercury in eggs. Breeding pairs of mallards were fed a control diet or diets containing 1, 2, 4, or 8 microg/g mercury, as methylmercury chloride. Mean concentrations of mercury in eggs laid by parents fed 0, 1, 2, 4, or 8 microg/g mercury were 0.0, 1.6, 3.7, 5.9, and 14 microg/g mercury on a wet-weight basis. There were no signs of mercury poisoning in the adults, and fertility and hatching success of eggs were not affected by mercury. Survival of ducklings and the number of ducklings produced per female were reduced by the 4 and 8-microg/g dietary mercury treatments (that resulted in 5.9 and 14 microg/g mercury in their eggs, respectively). Ducklings from parents fed the various mercury diets were just as heavy as controls at hatching, but by 6 days of age ducklings whose parents had been fed 4 or 8 microg/g mercury weighed less than controls. Because we do not know if absorption of mercury from our diets would be the same as absorption from natural foods, the mercury concentrations we report in eggs may be more useful in extrapolating to possible harmful effects in nature than are the dietary levels we fed. We conclude that mallard reproduction does not appear to be particularly sensitive to methylmercury.

  1. Reproduction in mallards exposed to dietary concentrations of methylmercury

    USGS Publications Warehouse

    Heinz, Gary H.; Hoffman, David J.; Klimstra, Jon D.; Stebbins, Katherine R.

    2010-01-01

    The purpose of this experiment was to use mallards (Anas platyrhynchos) tested under controlled conditions to determine how much harm to reproduction resulted from various concentrations of mercury in eggs. Breeding pairs of mallards were fed a control diet or diets containing 1, 2, 4, or 8 μg/g mercury, as methylmercury chloride. Mean concentrations of mercury in eggs laid by parents fed 0, 1, 2, 4, or 8 μg/g mercury were 0.0, 1.6, 3.7, 5.9, and 14 μg/g mercury on a wet-weight basis. There were no signs of mercury poisoning in the adults, and fertility and hatching success of eggs were not affected by mercury. Survival of ducklings and the number of ducklings produced per female were reduced by the 4 and 8-μg/g dietary mercury treatments (that resulted in 5.9 and 14 μg/g mercury in their eggs, respectively). Ducklings from parents fed the various mercury diets were just as heavy as controls at hatching, but by 6 days of age ducklings whose parents had been fed 4 or 8 μg/g mercury weighed less than controls. Because we do not know if absorption of mercury from our diets would be the same as absorption from natural foods, the mercury concentrations we report in eggs may be more useful in extrapolating to possible harmful effects in nature than are the dietary levels we fed. We conclude that mallard reproduction does not appear to be particularly sensitive to methylmercury.

  2. Sequential hair mercury in mothers and children from a traditional riverine population of the Rio Tapajós, Amazonia: seasonal changes.

    PubMed

    Malm, Olaf; Dórea, José G; Barbosa, Antonio C; Pinto, Fernando N; Weihe, Pal

    2010-10-01

    Riverine populations of the Brazilian Amazon depend on fish for their principal source of protein, which changes in availability with seasonal fluctuations in the aquatic ecosystem. We report seasonal (high and low waters) and interannual changes in total mercury and methylmercury concentrations in hair of subsistence fish-eaters from a traditional riverine village on the banks of the Rio Tapajós in the Brazilian Amazonia. Retrospective exposure assessment was conducted from hair concentrations in segments representative of 2 years. A total of 32 mothers and their 51 children were studied. They reported high fish consumption (4-14 times a week). Ranges of total mercury and methylmercury concentrations in hair were 1.0-51.0 and 0.5-41.4microgg(-1), with means of 12.4 and 10.2microgg(-1), respectively. The relative mean value for methylmercury was 80%. There was a significant correlation between mothers and children for both total-Hg (r=0.4826; P=0.003) and methyl-Hg (r=0.5214; P=0.004). Mercury concentrations along hair strands of individuals showed significant variation coinciding with seasonal high and low waters. The changes in the aquatic environment impacted fish species availability, which is reflected in the total and MeHg concentrations in hair.

  3. Liver mercury and methylmercury concentrations in New England common loons (Gavia immer)

    SciTech Connect

    Pokras, M.A.; Hanley, C.; Gordon, Z.

    1998-02-01

    Loons are of special interest to environmental scientists, who see them as a sentinel species for environmental health. This bird is a top predator in both fresh- and saltwater environments. A number of studies have been published regarding contaminant-related loon pathology, and they have repeatedly found Hg contamination and ingestion of lead fishing gear to be of particular concern. Since 1989 the authors have been studying regional patterns of loon mortality and have examined more than 400 birds. One segment of this study has been to document contaminants found in loons and to attempt to associate health effects with these contaminants. This article details some of their work on Hg in loons. Liver samples collected from common loons found dead were analyzed for mercury and methylmercury concentrations. Statistical analyses demonstrated no correlation between total mercury and methylmercury levels.

  4. Hair spray poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002705.htm Hair spray poisoning To use the sharing features on this page, please enable JavaScript. Hair spray poisoning occurs when someone breathes in (inhales) ...

  5. Forensic Science: Hair Identification.

    ERIC Educational Resources Information Center

    Keller, Elhannan L.

    1980-01-01

    Presented is an activity in which students use a microscope to do a forensic hair comparative study and a medullary classification. Mounting methods, medulla types, hair photographs, and activities are described. (DS)

  6. Bioengineering the Hair Follicle

    PubMed Central

    Parimoo, S; Zheng, Y; Barrows, T; Boucher, M; Washenik, K

    2007-01-01

    The hair follicle develops from the primitive embryonic epidermis as a result of complex epithelial-mesenchymal interactions. The full follicle, consisting of epithelial cylinders under control of a proximal lying mesenchymal papilla, grows in cycles giving rise to a new hair shaft during each cycle. The ability to cycle endows the follicle with regenerative properties. The evolution of hair follicle engineering began with the recognition in the early 1960's that hair follicles could be transplanted clinically into a foreign site and still grow a shaft typical of the donor site. Since that time, it has been found that the follicular papilla has hair follicle inducing properties and that the hair follicle houses within it epithelial stem cells that can respond to hair inductive signals. These findings have laid the foundation for isolating hair-forming cells, for expanding the cells in culture, and for forming new follicles in vivo. PMID:19279694

  7. Skin, Hair, and Nails

    MedlinePlus

    ... thousands of cells and hundreds of sweat glands, oil glands, nerve endings, and blood vessels. Skin is ... empty into hair follicles and pores, produce the oil sebum that lubricates the skin and hair. Sebaceous ...

  8. Forensic Science: Hair Identification.

    ERIC Educational Resources Information Center

    Keller, Elhannan L.

    1980-01-01

    Presented is an activity in which students use a microscope to do a forensic hair comparative study and a medullary classification. Mounting methods, medulla types, hair photographs, and activities are described. (DS)

  9. Influence of the cosmetic treatment of hair on drug testing.

    PubMed

    Jurado, C; Kintz, P; Menéndez, M; Repetto, M

    1997-01-01

    An important issue of concern for drug analysis in hair is the change in the drug concentration induced by the cosmetic treatment of hair. The products used for this treatment are strong bases and they are expected to cause hair damage. As a result drugs may be lost from the hair matrix or, under conditions of environmental contamination, be more easily incorporated into the hair matrix. We investigated the effects of cosmetic treatment in vivo by analysing hair samples selected from people who had treated their hair by bleaching or dyeing before sample collection. All of the subjects admitted a similar drug consumption during the time period for which the strands were analysed. Samples were viewed under a microscope to establish the degree of hair damage. Treated and untreated portions from each lock of hair were then selected, separated and analysed by standard detection procedures for cocaine, opiates, cannabinoids and nicotine. In all cases the drug content in hair that had undergone cosmetic treatment decreased in comparison to untreated hair. The majority of the mean differences were in the range of 40%-60% (cocaine, benzoylecgonine, codeine, 6-acetylmorphine and THC-COOH). For morphine the mean difference was higher than 60%, and two cases (THC and nicotine) differed by approx. 30%. These differences depended not only on the type of cosmetic treatment, as bleaching produced higher decreases than dyeing, but also on the degree of hair damage i.e. the more damaged the hair, the larger the differences in the concentration levels of drugs.

  10. Hair loss in women.

    PubMed

    Camacho-Martínez, Francisco M

    2009-03-01

    Female pattern hair loss (FPHL) is a clinical problem that is becoming more common in women. Female alopecia with androgen increase is called female androgenetic alopecia (FAGA) and without androgen increase is called female pattern hair loss. The clinical picture of typical FAGA begins with a specific "diffuse loss of hair from the parietal or frontovertical areas with an intact frontal hairline." Ludwig called this process "rarefaction." In Ludwig's classification of hair loss in women, progressive type of FAGA, 3 patterns were described: grade I or minimal, grade II or moderate, and grade III or severe. Ludwig also described female androgenetic alopecia with male pattern (FAGA.M) that should be subclassified according to Ebling's or Hamilton-Norwood's classification. FAGA.M may be present in 4 conditions: persistent adrenarche syndrome, alopecia caused by an adrenal or an ovarian tumor, posthysterectomy, and as an involutive alopecia. A more recent classification (Olsen's classification of FPHL) proposes 2 types: early- and late-onset with or without excess of androgens in each. The diagnosis of FPHL is made by clinical history, clinical examination, wash test, dermoscopy, trichoscan, trichograms and laboratory test, especially androgenic determinations. Topical treatment of FPHL is with minoxidil, 2-5% twice daily. When FPHL is associated with high levels of androgens, systemic antiandrogenic therapy is needed. Persistent adrenarche syndrome (adrenal SAHA) and alopecia of adrenal hyperandrogenism is treated with adrenal suppression and antiandrogens. Adrenal suppression is achieved with glucocorticosteroids. Antiandrogens therapy includes cyproterone acetate, drospirenone, spironolactone, flutamide, and finasteride. Excess release of ovarian androgens (ovarian SAHA) and alopecia of ovarian hyperandrogenism is treated with ovarian suppression and antiandrogens. Ovarian suppression includes the use of contraceptives containing an estrogen, ethinylestradiol, and a

  11. Interactions between methylmercury and selenomethionine injected into mallard eggs.

    PubMed

    Klimstra, Jon D; Yee, Julie L; Heinz, Gary H; Hoffman, David J; Stebbins, Katherine R

    2012-03-01

    Methylmercury chloride and seleno-L-methionine were injected separately or in combinations into mallard eggs (Anas platyrhynchos), and embryo mortality and teratogenic effects (deformities) were modeled using a logistic regression model. Methylmercury was injected at doses that resulted in concentrations of 0, 0.2, 0.4, 0.8, and 1.6 µg/g Hg in the egg on a wet weight basis and selenomethionine at doses that resulted in concentrations of 0, 0.1, 0.2, 0.4, and 0.6 µg/g Se in the egg, also on a wet weight basis. When selenomethionine and methylmercury were injected separately, hatching probability decreased in both cases. However, when methylmercury was injected at 1.6 µg/g in combination with selenomethionine at 0.2 µg/g, the presence of the methylmercury resulted in less embryo mortality than had been seen with 0.2 µg/g Se by itself, but it increased the number of deformed embryos and hatchlings. Selenomethionine appeared to be more embryotoxic than equivalent doses of methylmercury when injected into eggs, and both injected methylmercury and selenomethionine were more toxic to mallard embryos than when deposited naturally in the egg by the mother. The underlying mechanisms behind the interactions between methylmercury and selenomethionine and why methylmercury appeared to improve hatching probability of Se-dosed eggs yet increased deformities when the two compounds were combined are unclear. These findings warrant further studies to understand these mechanisms in both laboratory and field settings. Copyright © 2011 SETAC.

  12. Interactions between methylmercury and selenomethionine injected into mallard eggs

    USGS Publications Warehouse

    Klimstra, J.D.; Yee, J.L.; Heinz, G.H.; Hoffman, D.J.; Stebbins, K.R.

    2012-01-01

    Methylmercury chloride and seleno-L-methionine were injected separately or in combinations into mallard eggs (Anas platyrhynchos), and embryo mortality and teratogenic effects (deformities) were modeled using a logistic regression model. Methylmercury was injected at doses that resulted in concentrations of 0, 0.2, 0.4, 0.8, and 1.6 µg/g Hg in the egg on a wet weight basis and selenomethionine at doses that resulted in concentrations of 0, 0.1, 0.2, 0.4, and 0.6 µg/g Se in the egg, also on a wet weight basis. When selenomethionine and methylmercury were injected separately, hatching probability decreased in both cases. However, when methylmercury was injected at 1.6 µg/g in combination with selenomethionine at 0.2 µg/g, the presence of the methylmercury resulted in less embryo mortality than had been seen with 0.2 µg/g Se by itself, but it increased the number of deformed embryos and hatchlings. Selenomethionine appeared to be more embryotoxic than equivalent doses of methylmercury when injected into eggs, and both injected methylmercury and selenomethionine were more toxic to mallard embryos than when deposited naturally in the egg by the mother. The underlying mechanisms behind the interactions between methylmercury and selenomethionine and why methylmercury appeared to improve hatching probability of Se-dosed eggs yet increased deformities when the two compounds were combined are unclear. These findings warrant further studies to understand these mechanisms in both laboratory and field settings.

  13. Patients treated for male pattern hair with finasteride show, after discontinuation of the drug, altered levels of neuroactive steroids in cerebrospinal fluid and plasma.

    PubMed

    Caruso, Donatella; Abbiati, Federico; Giatti, Silvia; Romano, Simone; Fusco, Letizia; Cavaletti, Guido; Melcangi, Roberto Cosimo

    2015-02-01

    Observations performed in a subset of patients treated for male pattern hair loss indicate that persistent sexual side effects as well as anxious/depressive symptomatology have been reported even after discontinuation of finasteride treatment. Due to the capability of finasteride to block the metabolism of progesterone (PROG) and/or testosterone (T) we have evaluated, by liquid chromatography-tandem mass spectrometry, the levels of several neuroactive steroids in paired plasma and cerebrospinal fluid (CSF) samples obtained from post-finasteride patients and in healthy controls. At the examination, post-finasteride patients reported muscular stiffness, cramps, tremors and chronic fatigue in the absence of clinical evidence of any muscular disorder or strength reduction. Although severity of the anxious/depressive symptoms was quite variable in their frequency, overall all the subjects had a fairly complex and constant neuropsychiatric pattern. Assessment of neuroactive steroid levels in CSF showed a decrease of PROG and its metabolites, dihydroprogesterone (DHP) and tetrahydroprogesterone (THP), associated with an increase of its precursor pregnenolone (PREG). Altered levels were also observed for T and its metabolites. Thus, a significant decrease of dihydrotestosterone (DHT) associated with an increase of T as well as of 3α-diol was detected. Changes in neuroactive steroid levels also occurred in plasma. An increase of PREG, T, 3α-diol, 3β-diol and 17β-estradiol was associated with decreased levels of DHP and THP. The present observations show that altered levels of neuroactive steroids, associated with depression symptoms, are present in androgenic alopecia patients even after discontinuation of the finasteride treatment. This article is part of a Special Issue entitled 'Sex steroids and brain disorders'. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Work stress and hair cortisol levels among workers in a Bangladeshi ready-made garment factory - Results from a cross-sectional study.

    PubMed

    Steinisch, Maria; Yusuf, Rita; Li, Jian; Stalder, Tobias; Bosch, Jos A; Rahman, Omar; Strümpell, Christian; Ashraf, Hasan; Fischer, Joachim E; Loerbroks, Adrian

    2014-12-01

    Evidence on the association of work stress with cortisol levels is inconsistent and mostly stems from Western countries, with limited generalizability to other regions of the world. These inconsistencies may partly be due to methodological limitations associated with the measurement of cortisol secretion in saliva, serum or urine. The present study set out to explore associations of work stress with long-term integrated cortisol levels in hair among 175 workers of an export oriented ready-made garment (RMG) factory in Dhaka, Bangladesh. Work-related demands (WD), interpersonal resources (IR) and work-related values (WV) were assessed using a psychometrically evaluated interview. WD consisted of four items on physical demands, time pressure, worries about mistakes and exposure to abusive language. IR comprised five items addressing support, recognition, adequate payment, workers' trust in the management, and the management's trust in workers, as perceived by the workers. WV captured job security, promotion prospects and job latitude by three items. Hair cortisol concentrations (HCC) were analyzed by liquid chromatography-mass spectrometry. Stepwise multivariable linear regression models (backward elimination of predictors) were used to estimate associations of HCC with the three work stress components. For significant work stress component(s), further multivariable linear regression analyses were conducted to explore whether, and if so, which individual item(s) contributed most. The mean HCC equaled 3.27 (SD 2.58) pg/mg. HCC were found to be significantly associated with WV (beta=0.209, p=0.021). Additional analyses of the three WV items revealed that this association was largely driven the item on "promotion prospects" (beta=0.230, p=0.007) implying that the perception of good promotion prospects was associated with higher HCC. The finding of elevated HCC with good promotion prospects may initially seem counter-intuitive, but is supported by research documenting

  15. Exposure to methylmercury in utero: effects on biochemical development of catecholamine neurotransmitter systems

    SciTech Connect

    Bartolome, J.; Whitmore, W.L.; Seidler, F.J.; Slotkin, T.A.

    1984-08-06

    Administration of methylmercury to pregnant rats resulted in major alterations in synaptic dynamics of brain dopamine systems in the offspring which were prominent even at doses of the organomercurial which did not produce acute toxicity, fetal or neonatal death, low birth weight or reduced litter sizes. The abnormalities were typified by shortfalls in both the levels and turnover rate of the transmitter in vivo, accompanied by elevations in synaptic uptake as assessed in synaptosomal preparations in vitro. These effects were not apparent in the immediate postnatal period but instead showed a delayed onset beginning at about the time of weaning. Methylmercury exposure displayed selectivity in that central noradrenergic systems showed only the synaptic uptake alterations without changes in transmitter levels or turnover; targeted interactions were also apparent in peripheral sympathetic pathways to the heart and kidney. The threshold dose required to elicit damage to biochemical development of neurotransmitter systems was the same as that to alter more generalized cellular development, as assessed through measurements of brain ornithine decarboxylase activity. These studies indicate that neurochemical damage produced by prenatal exposure of the developing organism to methylmercury involves transmitter-selective alterations in synaptic dynamics and function which may contribute to adverse hehavioral outcomes; the underlying mechanisms, however, do not necessarily reflect actions of the organomercurial which are primary or specific to these particular neutronal tissues.

  16. Gestational Exposure to Methylmercury and Selenium: Effects on a Spatial Discrimination Reversal in Adulthood

    PubMed Central

    Reed, Miranda N; Paletz, Elliott M.; Newland, M. Christopher

    2007-01-01

    Selenium, a nutrient, and methylmercury, a developmental neurotoxicant, are both found in fish. There are reports that selenium sometimes ameliorates methylmercury’s neurotoxicity, but little is known about the durability of this protection after low-level gestational exposure. Developmental methylmercury exposure disrupts behavioral plasticity, and these effects extend well into adulthood and aging. The present experiment was designed to examine interactions between developmental low-level methylmercury and nutritionally relevant dietary selenium on discrimination reversals in adulthood. Female rats were exposed, in utero, to 0, 0.5, or 5 ppm mercury as methylmercury via drinking water, approximating mercury exposures of 0, 40, and 400 μg/kg/day. They also received both prenatal and postnatal exposure to a diet containing selenium from casein only (0.06 ppm) or 0.6 ppm selenium, creating a 2 (chronic Se) x 3 (gestational MeHg) full factorial design, with 6 – 8 rats per cell. Behavior was evaluated with a spatial discrimination procedure using two levers and sucrose reinforcers. All groups acquired the original discrimination similarly. Rats exposed to low selenium (0.06 ppm), regardless of MeHg exposure, required more sessions to complete the first reversal and made more omissions during this reversal than high selenium (0.6 ppm) animals, but the two diet groups did not differ on subsequent reversals. Rats exposed to MeHg, regardless of selenium exposure, made more errors than controls on the first and third reversals, which was away from the original discrimination. MeHg-exposed animals also had shorter choice latencies than controls during the first session of a reversal. Low selenium increased the number of omissions during a reversal, whereas high MeHg exposure produced perseverative responding (errors) on the lever that was reinforced during the original discrimination. However, there was no interaction between selenium and MeHg exposure. PMID:16759706

  17. Hair regrowth. Therapeutic agents.

    PubMed

    Shapiro, J; Price, V H

    1998-04-01

    Today there are new classes of hair growth promotors with proven efficacy. This article reviews the current state of the art agents for treatment of two of the most common forms of hair loss encountered in clinical practice, androgenetic alopecia and alopecia areata. Current therapeutic strategies are based on recent advances in the understanding of disordered hair growth. Practical treatment protocols are presented.

  18. Cartilage hair hypoplasia.

    PubMed Central

    Siggers, D. C.; Burke, J. B.; Morris, B.; Normand, I. C.; Tanner, J. M.; Williamson, D. A.

    1977-01-01

    Six cases of cartilage hair hypoplasia from five kindreds are described. They demonstrate variation in the expression of clinical features such as sparsity of hair, hair calibre, radiological changes, short stature and the extent of the disproportion between sitting height and stature. Images Figs. 1-6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 PMID:917962

  19. Hair transplantation surgery

    PubMed Central

    Khanna, Manoj

    2008-01-01

    Techniques in hair transplantation have evolved recently which make results look more natural. Hair restoration is one of the most exciting and innovative surgical fields in aesthetic surgery today. A precise appreciation of anatomy has allowed the use of follicular unit grafts. With better methods of harvesting and implantation, hair transplantation results represent a blend of art and science. PMID:20174544

  20. A Methylmercury Prediction Too For Surface Waters Across The Contiguous United States (Invited)

    NASA Astrophysics Data System (ADS)

    Krabbenhoft, D. P.; Booth, N.; Lutz, M.; Fienen, M. N.; Saltman, T.

    2009-12-01

    About 20 years ago, researchers at a few locations across the globe discovered high levels of mercury in fish from remote settings lacking any obvious mercury source. We now know that for most locations atmospheric deposition is the dominant mercury source, and that mercury methylation is the key process that translates low mercury loading rates into relatively high levels in top predators of aquatic food webs. Presently, almost all US states have advisories for elevated levels of mercury in sport fish, and as a result there is considerable public awareness and concern for this nearly ubiquitous contaminant issue. In some states, “statewide” advisories have been issued because elevated fish mercury levels are so common, or the state has no effective way to monitor thousands of lakes, reservoirs, wetlands, and streams. As such, resource managers and public health officials have limited options for informing the public on of where elevated mercury concentrations in sport fish are more likely to occur than others. This project provides, for the first time, a national map of predicted (modeled) methylmercury concentrations in surface waters, which is the most toxic and bioaccumulative form of mercury in the environment. The map is the result of over two decades of research that resulted in the formulation of conceptual models of the mercury methylation process, which is strongly governed by environmental conditions - specifically hydrologic landscapes and water quality. The resulting predictive map shows clear regional trends in the distribution of methylmercury concentrations in surface waters. East of the Mississippi, the Gulf and southeastern Atlantic coast, the northeast, the lower Mississippi valley, and Great Lakes area are predicted to have generally higher environmental methylmercury levels. Higher-elevation, well-drained areas of Appalachia are predicted to have relatively lower methylmercury abundance. Other than the prairie pothole region, in the western

  1. A generative sketch model for human hair analysis and synthesis.

    PubMed

    Chen, Hong; Zhu, Song-Chun

    2006-07-01

    In this paper, we present a generative sketch model for human hair analysis and synthesis. We treat hair images as 2D piecewise smooth vector (flow) fields and, thus, our representation is view-based in contrast to the physically-based 3D hair models in graphics. The generative model has three levels. The bottom level is the high-frequency band of the hair image. The middle level is a piecewise smooth vector field for the hair orientation, gradient strength, and growth directions. The top level is an attribute sketch graph for representing the discontinuities in the vector field. A sketch graph typically has a number of sketch curves which are divided into 11 types of directed primitives. Each primitive is a small window (say 5 x 7 pixels) where the orientations and growth directions are defined in parametric forms, for example, hair boundaries, occluding lines between hair strands, dividing lines on top of the hair, etc. In addition to the three level representation, we model the shading effects, i.e., the low-frequency band of the hair image, by a linear superposition of some Gaussian image bases and we encode the hair color by a color map. The inference algorithm is divided into two stages: 1) We compute the undirected orientation field and sketch graph from an input image and 2) we compute the hair growth direction forthe sketch curves and the orientation field using a Swendsen-Wang cut algorithm. Both steps maximize a joint Bayesian posterior probability. The generative model provides a straightforward way for synthesizing realistic hair images and stylistic drawings (rendering) from a sketch graph and a few Gaussian bases. The latter can be either inferred from a real hair image or input (edited) manually using a simple sketching interface. We test our algorithm on a large data set of hair images with diverse hair styles. Analysis, synthesis, and rendering results are reported in the experiments.

  2. Behavioral teratology of methylmercury in fish

    SciTech Connect

    Weis, P.; Weis, J.S.

    1994-12-31

    Embryos of the mummichog, Fundulus heteroclitus, were exposed to 2, 5, or 10 ug/l methylmercury throughout development. These are concentrations below those that can cause teratological effects. After hatching, larvae were maintained in clean sea water and tested for prey capture ability, using Artemia nauplii as prey. Individual fish larvae were provided with five brine shrimp and their capture times recorded. In all experiments, larvae that had been exposed to 10 ug/l methylmercury initially exhibited slower prey capture ability than the other groups. This is an indication of a subtle functional impairment due to the toxicant (``behavioral teratology``). However, the effect was transitory, and by about one week after hatching the prey capture of these larvae equaled that of the controls and the other treated groups. Growth of these larvae also equaled that of controls and the other groups. The embryonic exposure may have caused retardation of neurological development, which was subsequently compensated for, and therefore no permanent effects were produced. In the field, however, embryos exposed to such toxicants would probably continue to be exposed as larvae, and would not have the opportunity to recover from the effects, but rather might have them reinforced.

  3. The assessment of cortisol in human hair: associations with sociodemographic variables and potential confounders.

    PubMed

    Dettenborn, L; Tietze, A; Kirschbaum, C; Stalder, T

    2012-11-01

    To inform the future use of hair cortisol measurement, we have investigated influences of potential confounding variables (natural hair colour, frequency of hair washes, age, sex, oral contraceptive (OC) use and smoking status) on hair cortisol levels. The main study sample comprised 360 participants (172 women) covering a wide range of ages (1-91 years; mean = 25.95). In addition, to more closely examine influences of natural hair colour and you