Cadmium, mercury and lead in the blood of urban women in Croatia, the Czech Republic, Poland, Slovakia, Slovenia, Sweden, China, Ecuador and Morocco

Objectives

The aim of the study was to make an international comparison of blood levels of cadmium (B-Cd), lead (B-Pb) and mercury (B-Hg) of women in seven European, and three non-European cities, and to identify determinants.

Materials and Methods

About 50 women (age: 46–62) from each city were recruited (totally 480) in 2006–2009. Interview and questionnaire data were obtained. Blood samples were analysed in one laboratory to avoid interlaboratory variation.

Results

Between the European cities, the B-Pb and B-Cd results vary little (range of geometric means: 13.5–27.0 μg/l and 0.25–0.65 μg/l, respectively); the variation of B-Hg was larger (0.40–1.38 μg/l). Between the non-European cities the results for B-Pb, B-Cd and B-Hg were 19.2–68.0, 0.39–0.99 and 1.01–2.73 μg/l, respectively. Smoking was a statistically significant determinant for B-Cd, while fish and shellfish intakes contributed to B-Hg and B-Pb, amalgam fillings also contributed to B-Hg.

Conclusions

The present results confirm the previous results from children; the exposure to lead and cadmium varies only little between different European cities suggesting that other factors than the living area are more important. The study also confirms the previous findings of higher cadmium and lead levels in some non-European cities. The geographical variation for mercury is significant.     

National estimates of blood lead, cadmium, and mercury levels in the Korean general adult population

Objectives

To assess the extent of exposure to lead, cadmium, and mercury in the Korean general adult population using a representative sample.

Methods

We studied blood concentrations of three heavy metals in a representative sample of 1,997 Koreans as part of the Third Korean National Health and Nutrition Examination Survey (KNHANES III) performed in 2005.

Results

The geometric means of the blood lead, cadmium, and mercury concentrations were 2.61???g/dL, 1.53???g/L, and 4.15???g/L, respectively [95% confidence intervals (CIs), 2.50?C2.71, 1.48?C1.58, and 3.94?C4.36, respectively]. Women had significantly lower blood lead and mercury concentrations in adjusted and unadjusted analyses but no difference between genders was observed in blood cadmium analysis. The geometric means of blood lead and mercury levels were higher in subjects older than 40?years than in those younger than 40?years. Smoking status only affected the blood lead concentration, with this being higher in smokers than in nonsmokers. Blood cadmium levels did not differ with demographic and lifestyle variables after covariate adjustment. Blood mercury concentrations were higher in those who consumed alcohol and also increased with the frequency of fish consumption.

Conclusions

This biomonitoring study of blood heavy metals in the Korean general population as part of KNHANES III provides important reference data stratified by demographic and lifestyle factors that will be useful for the ongoing surveillance of environmental exposure of the Korean general population to heavy metals.     

Concentrations versus amounts of biomarkers in urine: a comparison of approaches to assess pyrethroid exposure

Background

In 2005, 84% of Wayana Amerindians living in the upper marshes of the Maroni River in French Guiana presented a hair mercury concentration exceeding the limit set up by the World Health Organization (10 μg/g). To determine whether this mercurial contamination was harmful, mice have been fed diets prepared by incorporation of mercury-polluted fish from French Guiana.

Methods

Four diets containing 0, 0.1, 1, and 7.5% fish flesh, representing 0, 5, 62, and 520 ng methylmercury per g, respectively, were given to four groups of mice for a month. The lowest fish regimen led to a mercurial contamination pressure of 1 ng mercury per day per g of body weight, which is precisely that affecting the Wayana Amerindians.

Results

The expression of several genes was modified with mercury intoxication in liver, kidneys, and hippocampus, even at the lowest tested fish regimen. A net genetic response could be observed for mercury concentrations accumulated within tissues as weak as 0.15 ppm in the liver, 1.4 ppm in the kidneys, and 0.4 ppm in the hippocampus. This last value is in the range of the mercury concentrations found in the brains of chronically exposed patients in the Minamata region or in brains from heavy fish consumers. Mitochondrial respiratory rates showed a 35–40% decrease in respiration for the three contaminated mice groups. In the muscles of mice fed the lightest fish-containing diet, cytochrome c oxidase activity was decreased to 45% of that of the control muscles. When mice behavior was assessed in a cross maze, those fed the lowest and mid-level fish-containing diets developed higher anxiety state behaviors compared to mice fed with control diet.

Conclusion

We conclude that a vegetarian diet containing as little as 0.1% of mercury-contaminated fish is able to trigger in mice, after only one month of exposure, disorders presenting all the hallmarks of mercurial contamination.     

End-stage renal disease and low level exposure to lead, cadmium and mercury; a population-based, prospective nested case-referent study in Sweden

Background

Cadmium (Cd), lead (Pb), and mercury (Hg) cause toxicological renal effects, but the clinical relevance at low-level exposures in general populations is unclear. The objective of this study is to assess the risk of developing end-stage renal disease in relation to Cd, Pb, and Hg exposure.

Methods

A total of 118 cases who later in life developed end-stage renal disease, and 378 matched (sex, age, area, and time of blood sampling) referents were identified among participants in two population-based prospective cohorts (130,000 individuals). Cd, Pb, and Hg concentrations were determined in prospectively collected samples.

Results

Erythrocyte lead was associated with an increased risk of developing end-stage renal disease (mean in cases 76 μg/L; odds ratio (OR) 1.54 for an interquartile range increase, 95% confidence interval (CI) 1.18-2.00), while erythrocyte mercury was negatively associated (2.4 μg/L; OR 0.75 for an interquartile range increase, CI 0.56-0.99). For erythrocyte cadmium, the OR of developing end-stage renal disease was 1.15 for an interquartile range increase (CI 0.99-1.34; mean Ery-Cd among cases: 1.3 μg/L). The associations for erythrocyte lead and erythrocyte mercury, but not for erythrocyte cadmium, remained after adjusting for the other two metals, smoking, BMI, diabetes, and hypertension. Gender-specific analyses showed that men carried almost all of the erythrocyte lead and erythrocyte cadmium associated risks.

Conclusions

Erythrocyte lead is associated with end-stage renal disease but further studies are needed to evaluate causality. Gender-specific analyses suggest potential differences in susceptibility or in exposure biomarker reliability.     

Blood lead,cadmium and mercury among children from urban,industrial and rural areas of Fez Boulemane Region (Morocco): Relevant factors and early renal effects

Objectives

To describe blood lead (Pb-B), cadmium (Cd-B) and mercury (Hg-B) levels in children living in urban, industrial and rural areas in Fez city (north of Morocco) and to identify the determinants and some renal effects of exposure.

Material and Methods

The study was conducted from June 2007 to January 2008 in 209 school children (113 girls, 96 boys), aged 6–12 years, from urban, industrial and rural areas in Fez city. Interview and questionnaires data were obtained. Blood and urinary samples were analyzed.

Results

The mean of blood lead levels (Pb-B) in our population was 55.53 μg/l (range: 7.5–231.1 μg/l). Children from the urban area had higher blood lead levels (BLLs) mean (82.36 μg/l) than children from industrial and rural areas (48.23 and 35.99 μg/l, respectively); with no significant difference between boys and girls. BLLs were associated with traffic intensity, passive smoking and infancy in the urban area. The mean of blood cadmium levels (BCLs) was 0.22 μg/l (range: 0.06–0.68 μg/l), with no difference between various areas. Rural boys had higher BCLs mean than rural girls, but no gender influence was noticed in the other areas. BCLs were associated with the number of cigarettes smoked at children’s homes. The blood mercury levels (BMLs) mean was 0.49 μg/l (range: 0.01–5.31 μg/l). The BMLs mean was higher in urban and industrial areas than in the rural area with no gender-related difference. BMLs were associated with amalgam fillings and infancy in the urban area. About 8% of the children had BLLs ≥ 100 μg/l particularly in the urban area, microalbuminuria and a decrease in height were noticed in girls from the inner city of Fez and that can be related to high BLLs (89.45 μg/l).

Conclusions

There is a need to control and regulate potential sources of contamination by these trace elements in children; particularly for lead.     

Population-based inorganic mercury biomonitoring and the identification of skin care products as a source of exposure in New York City

Background

Mercury is a toxic metal that has been used for centuries as a constituent of medicines and other items.

Objective

We assessed exposure to inorganic mercury in the adult population of New York City (NYC).

Methods

We measured mercury concentrations in spot urine specimens from a representative sample of 1,840 adult New Yorkers in the 2004 NYC Health and Nutrition Examination Survey. Cases with urine concentrations ≥ 20 μg/L were followed up with a telephone or in-person interview that asked about potential sources of exposure, including ritualistic/cultural practices, skin care products, mercury spills, herbal medicine products, and fish.

Results

Geometric mean urine mercury concentration in NYC was higher for Caribbean-born blacks [1.39 μg/L; 95% confidence interval (CI), 1.14–1.70] and Dominicans (1.04 μg/L; 95% CI, 0.82–1.33) than for non-Hispanic whites (0.67 μg/L; 95% CI, 0.60–0.75) or other racial/ethnic groups. It was also higher among those who reported at least 20 fish meals in the past 30 days (1.02 μg/L; 95% CI, 0.83–1.25) than among those who reported no fish meals (0.50 μg/L; 95% CI, 0.41–0.61). We observed the highest 95th percentile of exposure (21.18 μg/L; 95% CI, 7.25–51.29) among Dominican women. Mercury-containing skin-lightening creams were a source of exposure among those most highly exposed, and we subsequently identified 12 imported products containing illegal levels of mercury in NYC stores.

Conclusion

Population-based biomonitoring identified a previously unrecognized source of exposure to inorganic mercury among NYC residents. In response, the NYC Health Department embargoed products and notified store owners and the public that skin-lightening creams and other skin care products that contain mercury are dangerous and illegal. Although exposure to inorganic mercury is not a widespread problem in NYC, users of these products may be at risk of health effects from exposure.     

Indoor allergens in settled dust from kindergartens in city of Łódź, Poland

Objectives

The main objective of the study was to determine the levels of house dust mite (Der p1), dog (Can f1), cat (Fel d1) and cockroach (Bla g2) allergens in kindergartens localized in an urban agglomeration.

Material and Methods

A quantitative analysis of allergens was carried out in settled dust samples collected by vacuuming the floor surface in three kindergartens (N = 84) and children’s clothing (N = 36). The samples were collected in spring-summer and autumn-winter periods as well as at the beginning and end of the week. The allergen dust concentration was determined by enzyme-linked immunoenzymatic assay (ELISA).

Results

The mean geometric concentrations (±geometric standard deviations) of allergens Der p1, Can f1, Fel d1 and Bla g2 determined in kindergartens were: 0.02±3.21 μg/g of dust; 0.97±4.49 μg/g of dust; 0.30±4.43 μg/g of dust and 0.01±3.08 μg/g of dust, respectively. Younger classrooms (children aged from 3 to 4 years) were characterized by almost twice higher mean concentration of allergen Fel d1, as compared to older classrooms (children aged from 5 to 6 years) (p < 0.05). A significant impact of seasonality on the level of dog allergen Can f1 was found (p < 0.05). No significant weekly variation was found in average concentrations of the allergens. Children who had a dog and/or cat at home were characterized by high concentrations of allergens Can f1 and Fel d1 on their clothes (59.2±5.39 μg Can f1/g of dust; 3.63±1.47 μg Fel d1/g of dust), significantly higher than concentrations of allergens in children who did not have any pets (p < 0.001).

Conclusions

Special attention should be paid to keeping the kindergarten rooms tidy and clean and to an appropriate choice of furnishings and fittings which would prevent the proliferation of the house dust mite and accumulation of allergens.     

Airborne particulate matter and mitochondrial damage: a cross-sectional study

Background

Arsenic is a potent pollutant that has caused an environmental catastrophe in certain parts of the world including Bangladesh where millions of people are presently at risk due to drinking water contaminated by arsenic. Chronic arsenic exposure has been scientifically shown as a cause for liver damage, cancers, neurological disorders and several other ailments. The relationship between plasma cholinesterase (PChE) activity and arsenic exposure has not yet been clearly documented. However, decreased PChE activity has been found in patients suffering liver dysfunction, heart attack, cancer metastasis and neurotoxicity. Therefore, in this study, we evaluated the PChE activity in individuals exposed to arsenic via drinking water in Bangladesh.

Methods

A total of 141 Bangladeshi residents living in arsenic endemic areas with the mean arsenic exposure of 14.10 ± 3.27 years were selected as study subjects and split into tertile groups based on three water arsenic concentrations: low (< 129 μg/L), medium (130-264 μg/L) and high (> 265 μg/L). Study subjects were further sub-divided into two groups (≤50 μg/L and > 50 μg/L) based on the recommended upper limit of water arsenic concentration (50 μg/L) in Bangladesh. Blood samples were collected from the study subjects by venipuncture and arsenic concentrations in drinking water, hair and nail samples were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). PChE activity was assayed by spectrophotometer.

Results

Arsenic concentrations in hair and nails were positively correlated with the arsenic levels in drinking water. Significant decreases in PChE activity were observed with increasing concentrations of arsenic in water, hair and nails. The average levels of PChE activity in low, medium and high arsenic exposure groups were also significantly different between each group. Lower levels of PChE activity were also observed in the > 50 μg/L group compared to the ≤50 μg/L group. Moreover, PChE activity was significantly decreased in the skin (+) symptoms group compared to those without (-).

Conclusions

We found a significant inverse relationship between arsenic exposure and PChE activity in a human population in Bangladesh. This research demonstrates a novel exposure-response relationship between arsenic and PChE activity which may explain one of the biological mechanisms through which arsenic exerts its neuro-and hepatotoxicity in humans.     

Indoor air particles in office buildings with suspected indoor air problems in the Helsinki area

Objectives

Airborne particle concentrations can be used as quality indicators of indoor environments. The previous lack of reference data has limited the use of particle measurements in office environments. The aim of this study was to describe the concentrations of airborne particles (≥ 0.5 μm and ≥ 5.0 μm) in 122 Finnish office buildings with suspected indoor air problems.

Materials and Methods

The database consisted of indoor air and supply air particle samples collected in 2001–2006 from the Helsinki area. The particle concentrations (≥ 0.5 μm and ≥ 5.0 μm) were measured in the indoor air (528 samples from 122 office rooms) and in the supply air (384 samples from 105 office rooms) with an optical particle counter. Airborne particle concentrations ≥ 0.5 μm were categorized according to the efficiency of supply air filtration and health survey data.

Results

The mean concentrations in the indoor air equaled 1900 particles/l and in the supply air 1300 particles/l. The efficiency of supply air filtration decreased the fine particles counts in both the indoor and supply air. The counts of large particles, ≥ 5.0 μm, were low in the indoor air. Airborne counts of ≥ 0.5 μm particles (geometric mean) were statistically higher in the offices whose occupants had work-related symptoms (eye and/or upper respiratory symptoms or upper respiratory infections) than in the offices whose occupants had no such symptoms. However, the symptoms may also be linked to other indoor air problems or particle characteristics not studied in this work.

Conclusions

This study indicates typical airborne particle levels (≥ 0.5 μm and ≥ 5.0 μm) in Finnish office buildings with suspected indoor air problems. The results can be used to evaluate the quality of indoor environment, possible indoor air problems, and the need for additional investigations.     

Perfluorinated Compounds,Polychlorinated Biphenyls,and Organochlorine Pesticide Contamination in Composite Food Samples from Dallas,Texas, USA

Objectives

The objective of this article is to extend our previous studies of persistent organic pollutant (POP) contamination of U.S. food by measuring perfluorinated compounds (PFCs), organochlorine pesticides, and polychlorinated biphenyls (PCBs) in composite food samples. This study is part of a larger study reported in two articles, the other of which reports levels of polybrominated diphenyl ethers and hexabromocyclododecane brominated flame retardants in these composite foods [Schecter et al. 2010. Polybrominated diphenyl ethers (PBDEs) and hexabromocyclodecane (HBCD) in composite U.S. food samples, Environ Health Perspect 118:357–362].

Methods

In this study we measured concentrations of 32 organochlorine pesticides, 7 PCBs, and 11 PFCs in composite samples of 31 different types of food (310 individual food samples) purchased from supermarkets in Dallas, Texas (USA), in 2009. Dietary intake of these chemicals was calculated for an average American.

Results

Contamination varied greatly among chemical and food types. The highest level of pesticide contamination was from the dichlorodiphenyltrichloroethane (DDT) metabolite p,p′- dichlorodiphenyldichloroethylene, which ranged from 0.028 ng/g wet weight (ww) in whole milk yogurt to 2.3 ng/g ww in catfish fillets. We found PCB congeners (28, 52, 101, 118, 138, 153, and 180) primarily in fish, with highest levels in salmon (PCB-153, 1.2 ng/g ww; PCB-138, 0.93 ng/g ww). For PFCs, we detected perfluorooctanoic acid (PFOA) in 17 of 31 samples, ranging from 0.07 ng/g in potatoes to 1.80 ng/g in olive oil. In terms of dietary intake, DDT and DDT metabolites, endosulfans, aldrin, PCBs, and PFOA were consumed at the highest levels.

Conclusion

Despite product bans, we found POPs in U.S. food, and mixtures of these chemicals are consumed by the American public at varying levels. This suggests the need to expand testing of food for chemical contaminants.     

Medicine students and exposure to environmental tobacco smoke

Objective

Although medicine students express positive attitudes toward providing lifestyle counseling, they require more instruction in many areas of health behavior in order to be helpful to their patients. The presented study included the students’ questionnaires analysis regarding their lifestyle and exposure to tobacco smoke. The aim of this study was to examine students’ exposure to chosen xenobiotics by determination of selected biomarkers in urine samples, which underlay the basis for exposure assessment towards tobacco smoke.

Materials and Methods

The investigated group consisted of first- and second-year medicine students from the Silesian Medical University (N = 133). Data obtained from a questionnaire survey was compared with the results of chosen biomarkers determined in urine samples. The analyses of the main nicotine metabolites were carried out firstly with use of ELISA, followed by the TLC technique with densitometry.

Results

According to questionnaires, every third student examined was exposed to passive smoking. The mean concentration of the main nicotine metabolites determined by ELISA in urine samples of smoking students was 1293.52±396.70 μg/g creatinine. The results of the TLC analysis in the group of smoking students were as follows: for cotinine ? 523.10±68.10 μg/g creatinine and for trans-3’-hydroxycotinine ? 653.81±62.30 μg/g creatinine.

Conclusions

Medicine students, regardless of their area of study, are a highly-exposed part of the population to tobacco smoke, not only actively but also passively. Tobacco smoke exposure can be assessed by ELISA as a screening method as well as by more specific TLC technique with densitometry.     

Fish consumption and mercury exposure among Louisiana recreational anglers

Background

Methylmercury (MeHg) exposure assessments among average fish consumers in the United States may underestimate exposures among U.S. subpopulations with high intakes of regionally specific fish.

Objectives

We examined relationships among fish consumption, estimated mercury (Hg) intake, and measured Hg exposure within one such potentially highly exposed group, recreational anglers in the state of Louisiana, USA.

Methods

We surveyed 534 anglers in 2006 using interviews at boat launches and fishing tournaments combined with an Internet-based survey method. Hair samples from 402 of these anglers were collected and analyzed for total Hg. Questionnaires provided information on species-specific fish consumption during the 3 months before the survey.

Results

Anglers’ median hair Hg concentration was 0.81 μg/g (n = 398; range, 0.02–10.7 μg/g); 40% of participants had levels >1 μg/g, which approximately corresponds to the U.S. Environmental Protection Agency’s reference dose. Fish consumption and Hg intake were significantly positively associated with hair Hg. Participants reported consuming nearly 80 different fish types, many of which are specific to the region. Unlike the general U.S. population, which acquires most of its Hg from commercial seafood sources, approximately 64% of participants’ fish meals and 74% of their estimated Hg intake came from recreationally caught seafood.

Conclusions

Study participants had relatively elevated hair Hg concentrations and reported consumption of a wide variety of fish, particularly locally caught fish. This group represents a highly exposed subpopulation with an exposure profile that differs from fish consumers in other regions of the United States, suggesting a need for more regionally specific exposure estimates and public health advisories.     

Mercury accumulation in largemouth bass (Micropterus salmoides) in a Florida Lake

Rates of mercury accumulation were examined in male and female largemouth bass (Micropterus salmoides) from Lake Tohopekaliga, Florida, to establish methods for fish consumption advisories for the protection of human health. In addition, concentrations were determined in five lower trophic level fish species. Total mercury concentrations in adult largemouth bass muscle tissue ranged from 0.16 to 1.10 g/g (fresh weight) and increased as fish increased in size and age. Wholebody mercury concentrations of 1990 year-class largemouth bass increased from 0.05 g/g at 20 mm and to 0.32 g/g at 320 mm (age 2). Significant differences were found in the rates of accumulation between sexes for length and weight, but not for age. Therefore, standardized mercury concentrations were determined using bass age to make comparisons among sampling dates. Although there were significant differences in adjusted mean mercury concentrations among two sampling dates, mercury content of standard-age bass remained relatively constant over time. Largemouth bass exceed the Florida Health Advisory level for limited consumption of fish (0.50 g Hg/g) based on a mean concentration of 0.59 g/g for 64 bass. Advisories based on fish morphological characteristics (i.e., length, weight) or age are not possible for Lake Tohopekaliga due to differences in mercury accumulation in male and female bass. Lower trophic level species of sport fish did not exceed the limited consumption level.     

Biomonitoring as an intervention against methylmercury exposure

Objectives

We evaluated the effectiveness of biomonitoring as an intervention against methylmercury exposure.

Methods

During 2004, the Wisconsin Department of Health Services assessed fish consumption and methylmercury exposure among 2,031 men and women who responded to a statewide press release. People whose hair mercury levels exceeded 1 microgram per gram (μg/g) were advised to reduce their intake of large, predatory fish. Others were informed that mercury exposure was not an issue for them and were encouraged to continue to eat fish as part of a healthy diet. In 2008, follow-up questionnaires and hair sampling kits were mailed to all 2004 study participants.

Results

Completed surveys and hair samples were received from 1,139 individuals. While overall fish intake for this group increased slightly, from 8,561 to 8,785 servings per month between 2004 and 2008, the intake rate was significantly reduced among people whose 2004 hair mercury levels were >1 μg/g, and 30% of the cohort reported eating different types of fish or smaller fish in 2008. The number of people who had a hair mercury level >1 μg/g fell from 300 in 2004 to 206 in 2008.

Conclusions

Hair mercury analysis and explanatory result letters appear to have had a long-term effect on methylmercury exposure and the selection of fish. These findings support the public health benefit of methylmercury screening in conjunction with results-based education among frequent consumers of commercial and sport-caught fish.Eating a diet that includes a variety of fish, especially fatty marine species such as herring, mackerel, and sardines, has been associated with a reduced risk of cardiovascular disease.^1–4 However, consumption of methylmercury-contaminated fish or grain has been linked to a variety of health problems ranging from developmental delays in prenatally exposed infants to neurological problems and heart disease.^5–11 Most state health departments advise children and women of childbearing age to reduce their intake of large, predatory sport fish, which are frequently high in mercury. Following publication of the 2000 National Research Council report on the toxicological effects of methylmercury,¹² the Wisconsin Department of Health Services began to offer hair mercury testing to concerned citizens and broadened its advisory to include dietary guidance for men and older women.The Great Lakes Regional Collaboration (GLRC) has set a goal of protecting the public from toxic substances through effective outreach and education, including protective fish consumption advice throughout the Great Lakes Basin Ecosystem.¹³ In addition, the GLRC has encouraged stakeholders to identify and fill knowledge gaps that limit our ability to manage public health risks posed by substances found in the Great Lakes and has recommended the use of consistent, easily accessible messages on fish consumption to protect human health. By 2010, the GLRC hoped to establish a regional biomonitoring program for persistent contaminants, and this initiative was recently funded through grants offered by the U.S. Agency for Toxic Substances and Disease Registry.In 2004, the Wisconsin Department of Health Services assessed methylmercury levels in 2,031 residents.¹⁴ Volunteers recruited using statewide press releases completed questionnaires that requested information about sport-caught and commercial fish consumption, and provided hair samples for analysis. Compared with responses from a fish consumption module included in the 2004 Wisconsin Behavioral Risk Factor Surveillance System (WBRFSS) survey, participants in this study ate more fish and were more likely to be licensed anglers. Nearly 20% of the hair samples exceeded the federal advisory level of 1 microgram per gram (μg/g). Levels were highest in male anglers and lowest in women of childbearing age. These results suggested that the advisory used prior to 2005, which advised women who were pregnant or were planning a pregnancy to avoid eating large, predatory fish, had been effective in reducing mercury exposure among this group and highlighted the need to provide consumption advice to men.To assess the effectiveness of the 2004 biomonitoring effort as an outreach and intervention tool, a follow-up investigation was conducted in 2008. The follow-up study was designed to evaluate the participants'' recall of their 2004 hair mercury level, as well as any changes in their fish intake and hair mercury level. This article presents findings from the follow-up study.     

Occupational exposure to airborne mercury during gold mining operations near El Callao, Venezuela

Objective: The National Institute for Occupational Safety and Health (NIOSH) recently conducted a cross–sectional study during gold mining operations near El Callao, Venezuela. The purpose of the study was to assess mercury exposures and mercury-related microdamage to the kidneys. The study consisted of concurrent occupational hygiene and biological monitoring, and an examination of the processing techniques employed at the different mining facilities. Mercury was used in these facilities to remove gold by forming a mercury-gold amalgam. The gold was purified either by heating the amalgam in the open with a propane torch or by using a small retort. Methods: Thirty-eight workers participated in this study. Some participants were employed by a large mining company, while others were considered “informal miners” (self-employed). Mercury exposure was monitored by sampling air from the workers' breathing zones. These full-shift air samples were used to calculate time-weighted average (TWA) mercury exposure concentrations. A questionnaire was administered and a spot urine sample was collected. Each urine sample was analyzed for mercury, creatinine, and N-acetyl-ß-d-glucosaminidase (NAG). Results: The range for the 8-h TWA airborne mercury exposure concentrations was 0.1 to 6,315?μg/m³, with a mean of 183?μg/m³. Twenty percent of the TWA airborne mercury exposure measurements were above the NIOSH recommended exposure limit (REL) of 50?μg/m³, and 26% exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 25?μg/m³. The mean urine mercury concentration was 101?μg/g creatinine (μg/g-Cr), and the data ranged from 2.5 to 912?μg/g-Cr. Forty–two percent of the study participants had urine mercury concentrations that exceeded the ACGIH biological exposure index (BEI) of 35?μg/g-Cr. Urinary NAG excretion is considered a biological marker of preclinical, nonspecific microdamage to the kidney's proximal tubule cells. The mean urine NAG concentration was 3.6 International Units/g-Cr (IU/g-Cr) with a range of 0.5 to 11.5?IU/g-Cr. Three workers had urine NAG levels in excess of the reference values. Correlation analyses found statistically significant correlations between airborne mercury exposure and urine mercury level (P=0.01), and between urine mercury level and urine NAG excretion (P=0.01). In addition, the airborne mercury exposure data and urine mercury data were segregated by job tasks. A Wilcoxon rank sum test revealed significant correlations between tasks and mercury exposure (P=0.03), and between tasks and urine mercury level (P=0.02). Conclusions: The tasks with the highest mean airborne mercury exposures were “burning the mercury-gold amalgam” and “gold refining/smelting”. Recommendations were provided for improving the retort design to better contain mercury, for ventilation in the gold shops, and for medical surveillance and educational programs.     

Associations of Prenatal Mercury Exposure From Maternal Fish Consumption and Polyunsaturated Fatty Acids With Child Neurodevelopment: A Prospective Cohort Study in Italy

Background

Mercury is a neurotoxin, and limited prenatal exposure to it can affect long-term child neurodevelopment. However, results of epidemiologic studies of such exposure have been inconsistent. We examined the association of prenatal mercury exposure from maternal fish consumption with child neurodevelopment in northern Italy.

Methods

A population-based cohort of 606 children and their mothers was studied from pregnancy to age 18 months. Mercury levels were measured in maternal hair and blood during pregnancy and in umbilical cord blood and breast milk. Levels of polyunsaturated fatty acids (PUFAs) were measured in maternal serum. Maternal and child intakes of fish were assessed by using a food frequency questionnaire. The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) was used to evaluate child neurodevelopment. Multivariate linear regression was used to examine the association of mercury exposure with BSID-III scores, after controlling for maternal fish intake, PUFAs during pregnancy, and several other confounders.

Results

Mean weekly fish intake during pregnancy was less than 2 servings. Mercury concentrations in biological samples were low (mean, 1061 ng/g in hair) and moderately correlated with fish intake, particularly of carnivorous species. Maternal ω-3 PUFA concentrations were poorly correlated with fish intake. Maternal intelligence quotient (IQ) and child intake of fish were significantly associated with neurodevelopment scores. In multivariate models, the level of Hg exposure was not associated with neurodevelopmental performance at 18 months.

Conclusions

In this Italian population, neurodevelopment at 18 months was associated with child intake of fresh fish and maternal IQ rather than with mercury exposure. The expected beneficial effect of maternal fish intake (from maternal ω-3 PUFAs) was not found.Key words: mercury, polyunsaturated fatty acids, nervous system development, fish, Bayley Scales of Infant and Toddler Development     

Total prohibition of smoking but not partial restriction effectively reduced exposure to tobacco smoke among restaurant workers in Finland

Objectives

To assess work-related exposure to tobacco smoke in Finnish restaurants, a series of nationwide questionnaire surveys were conducted among restaurant workers and the levels of indoor air nicotine concentrations were measured in restaurants. The survey aimed to evaluate the impact of the smoke-free legislation in general and in particular after the total smoking ban launched in 2007.

Materials and Methods

In 2003–2010, four national questionnaire surveys were conducted among restaurant workers and the concentration of nicotine in indoor air was measured in different types of restaurants, bars and nightclubs.

Results

Between 2003 and 2010, the proportion of restaurant workers reporting occupational exposure to tobacco smoke dropped from 59% to 11%. Among pub workers, the decrease was from 97% to 18% and in workers of dining restaurants from 49% to 10%, respectively. The median concentration of nicotine in indoor air of all restaurants decreased from 11.7 μg/m³ to 0.1 μg/m³. The most significant decrease was detected in pubs where the decrease was from 16.1 μg/m³ to 0.1 μg/m³. Among all restaurant workers, in 2003–2010 the prevalence of daily smokers was reduced from 39% to 31% in men and from 35% to 25% in women.

Conclusion

Total prohibition of smoking but not partial restriction in restaurants was effective in reducing work-related exposure to tobacco smoke. Strict tobacco legislation may partly be associated with the significant decrease of daily smoking prevalence among restaurant workers.     

Latex sensitization and risk factors in female nurses in Thai governmental hospitals

Objectives

Exposure to latex allergens in latex gloves can cause occupational health problems in nurses, yet latex gloves are still widely used in Thai hospitals. Therefore, we conducted a study to determine the prevalence of latex sensitization in nurses and identify risk factors associated with sensitization.

Materials and Methods

A questionnaire, providing information on personal characteristics, ill-health, working conditions and symptoms related to latex product use, was administered to 363 female nurses working in two tertiary hospitals in southern Thailand. Latex sensitization was confirmed using a solid phase immunoassay to detect anti-latex IgE antibodies. Total glove protein levels were determined by using a modified Lowry method and latex aeroallergens by a competitive inhibition immunoassay.

Results

The overall prevalence of latex sensitization was 4.4%. Respiratory symptoms related to latex glove use were significantly associated with latex sensitization (OR = 5.5, 95% CI: 1.57–19). Total glove protein levels ranged 87.8–250.8 μg protein/dm². The prevalence of latex sensitization was higher (6.6% vs. 2.2%) in the hospital where gloves with higher protein levels (82–438 μg/g vs. 86–170 μg/g) were used. Furthermore, latex sensitization prevalence increased from 3% to 5% with increased average departmental aeroallergen concentrations.

Conclusions

Latex sensitization prevalence in Thai nurses was higher than previously reported. Respiratory exposure seems to play an important role, in addition to dermal exposure. If latex gloves cannot be replaced by non-latex alternatives, replacement with gloves with lower protein content should be considered.     

Mercury Concentrations in the Fish Community from Indrawati River,Nepal

This study quantified concentrations of mercury (Hg) and its trophic transfer along the fish community in the Indrawati River, Nepal. Stable isotope ratios of nitrogen (δ¹⁵N) and carbon (δ¹³C), complemented by stomach contents data were used to assess the food web structure and trophic transfer of Hg in 54 fishes; 43 Shizothorax richardsonii and 11 Barilius spp. [B. bendelisis (1), B. vagra (3) and B. barila (7)]. Sixty-one muscle samples (including six replicates) were used for the analysis of total mercury (THg) and stable isotopes. Mean THg concentrations in B. spp. and the more common species S. richardsonii was observed to be 218.23 (ng/g, ww) and 90.82 (ng/g, ww), respectively. THg versus total length in both S. richardsonii and B. spp. showed a decreasing tendency with an increase in age. Regression of logTHg versus δ¹⁵N among the fish species showed a significant positive correlation only in S. richardsonii indicating biomagnification along the trophic level in this species.