German Environmental Survey 1998 (GerES III): environmental pollutants in blood of the German population

Update of the reference and HBM values derived by the German Human Biomonitoring Commission

In 2007, we reviewed the working principles and working procedures of the German Human Biomonitoring Commission together with the reference values and human biomonitoring (HBM) values derived up to that time. Since then, the Commission has decided to derive additionally HBM I values on the basis of tolerable daily intakes and has used and evaluated this new approach on the metabolites of (2-ethylhexyl) phthalate (DEHP) in urine. Furthermore, the Commission has derived a HBM I value for thallium in urine, has recinded the HBM values for lead in blood, and has updated the HBM values for cadmium in urine. Based on the representative data of the German Environmental Survey on Children from 2003 to 2006 (GerES IV), the Commission has updated the reference values for a large number of environmental pollutants in urine and blood of children in Germany. Since 2007, the Commission has derived new and updated reference values for PFOS and PFOA in human plasma, for thallium in urine, for aromatic amines in urine, for a comprehensive number of phthalate metabolites in urine, and for organochlorine pesticides in human breast milk. Furthermore, the Commission has evaluated background exposure levels for two naphthalene metabolites and acrylamide (using acrylamide-haemoglobin adduct) for the general population. This paper reports the new values, including those already published, in order to provide an updated overview.

β-Hexachlorocyclohexane levels in serum and risk of Parkinson's disease

Pesticide exposure has been implicated as an environmental risk factor for the development of Parkinson's disease (PD). However, few studies have identified specific pesticides. Previously, we identified elevated serum levels of the organochlorine pesticide β-hexachlorocyclohexane (β-HCH) in PD patients from a small clinical sample. Here, we conducted a case-control study to confirm the association between β-HCH and PD in a larger sample size (n=283) with serum samples of PD patients and controls obtained from UT Southwestern Medical Center and Emory University. Samples were obtained from two discrete periods at both sites, 2001-2003 and 2006-2008, and were analyzed for β-HCH levels. Adjusted odds ratios (ORs) for PD were estimated using logistic regression and generalized estimating equations. The mean serum β-HCH level across all cohorts in this study was 22.3 ng/mg cholesterol (range: 0-376.7), and the levels were significantly higher and samples collected in 2001-2003 vs. 2006-2008. After controlling for age and gender, the OR for increased risk of PD for every 1 ng/mg increase in serum β-HCH ranged from 1.02 to 1.12 across the four different cohorts, and 1.03 (95% CI: 1.00-1.07, p value=0.031) in the pooled analysis. Furthermore, the OR for increased risk of PD of subjects having serum β-HCH levels above the inter-quartile range of 39.08 ng/mg cholesterol was 2.85 (95% CI: 1.8, 4.48; p value<0.001). These data are consistent with environmental decreases in β-HCH levels between 2001 and 2008, but they indicate that elevated levels of serum β-HCH are still associated with heightened risk for PD.

Blood lead levels in the adult population living in France the French Nutrition and Health Survey (ENNS 2006-2007)

BACKGROUND

The French Nutrition and Health Survey (ENNS) was conducted in order to describe food consumption and levels of various biomarkers in the general population. In this paper, we aimed to assess the distribution of blood lead levels (BLL) in the adult population living in France.

METHOD

ENNS was a cross-sectional survey carried out in the general population. Participants (18-74years of age) were sampled using a three-stage probability design stratified by geographical areas and degrees of urbanization. Collected data included biochemical samples, anthropometric measurements, socio-demographic characteristics, and environmental and occupational exposure.

RESULTS

In 2006/2007, 2029 adults were included in the survey on lead. The blood lead geometric mean (GM) in the population living in France was 25.7μg/L [24.9-26.5]. The overall prevalence of elevated BLL (>100μg/L) was 1.7% [1.1-2.3%]. Levels were significantly higher in males than in females, and increased with age, smoking status and alcohol consumption. Other factors significantly associated with BLL were leisure activities, occupational category, age of housing unit, birth place and shellfish/crustacean consumption.

CONCLUSION

For the first time a survey provides national estimates of BLL for the adult population in France. Comparison with results from a previous study among men aged 18-28years showed that the GM dropped more than 60% in the last 10years. The distribution of BLL in France was quite similar to that observed in other European countries.

Is dental amalgam safe for humans? The opinion of the scientific committee of the European Commission

It was claimed by the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR)) in a report to the EU-Commission that "....no risks of adverse systemic effects exist and the current use of dental amalgam does not pose a risk of systemic disease..." [1, available from: http://ec.europa.eu/health/ph_risk/committees/04_scenihr/docs/scenihr_o_016.pdf].SCENIHR disregarded the toxicology of mercury and did not include most important scientific studies in their review. But the real scientific data show that:(a) Dental amalgam is by far the main source of human total mercury body burden. This is proven by autopsy studies which found 2-12 times more mercury in body tissues of individuals with dental amalgam. Autopsy studies are the most valuable and most important studies for examining the amalgam-caused mercury body burden.(b) These autopsy studies have shown consistently that many individuals with amalgam have toxic levels of mercury in their brains or kidneys.(c) There is no correlation between mercury levels in blood or urine, and the levels in body tissues or the severity of clinical symptoms. SCENIHR only relied on levels in urine or blood.(d) The half-life of mercury in the brain can last from several years to decades, thus mercury accumulates over time of amalgam exposure in body tissues to toxic levels. However, SCENIHR state that the half-life of mercury in the body is only "20-90 days".(e) Mercury vapor is about ten times more toxic than lead on human neurons and with synergistic toxicity to other metals.(f) Most studies cited by SCENIHR which conclude that amalgam fillings are safe have severe methodical flaws.

Blood lead and cadmium levels in a six hospital employee population. PESA study, 2009

INTRODUCTION

Exposure to lead and cadmium is a public health problem due to the broad exposure to these toxic substances among the general population. The objective of this study is to determine blood lead and cadmium concentrations in a working population drawn from six university hospitals in Madrid, Getafe, Cartagena, Santiago de Compostela, Santander and Palma de Mallorca (Spain) and to identify associated factors.

MATERIALS AND METHODS

951 individuals participated in the study and were administered the standardized PESA® questionnaire regarding exposure to lead and cadmium. The blood lead and cadmium concentrations were measured by electrothermal atomization atomic absorption spectrometry with Zeeman background correction in Perkin-Elmer spectrometers, guaranteeing the transferability of the results.

RESULTS

The median overall blood lead concentration was: 1.6 μg/dL (IQR: 0.9-2.7) and that of cadmium was: 0.21 μg/L (IQR: 0.10-0.50). There were significant differences in lead levels between men (2 μg/dL) and women (1.5 μg/dL), postmenopausal (2.6 μg/dL) and premenopausal women (1.1 μg/dL), and between participants who cooked in earthenware (2.1 μg/dL) and those who did not (1.5 μg/dL). The median of cadmium in women (0.24 μg/L) was higher than in men (0.11 μg/L) and was also higher in subjects who smoked (0.70 μg/L) than in non-smokers (0.13 μg/L).

CONCLUSIONS

A reduction in blood lead and cadmium levels was observed with respect to previous studies carried out in Spain. Nevertheless, the results suggest there are certain factors which increase risk such as age, gender, menopause, age of housing, cooking in lead-glazed earthenware and exposure to cigarette smoke.

Lead exposure in female workers who are pregnant or of childbearing age

In adults, high-level lead exposure often occurs in the lead-related industries. Acute lead poisoning has become rare, but chronic exposure to low-level lead remains a public health issue. With recent advances in our understanding of lead toxicity at low-levels, researchers have shifted their focus to studying lead at concentrations below those currently recommended as 'acceptable' in worker protection. As gender plays an important role in the storage, biokinetics, and toxicity of lead, it seems inappropriate to extrapolate findings of lead exposure in men to women. Women's bones release lead more slowly to the bloodstream, so blood levels remain increased for a long time after cessation of high exposure, reflecting the endogenous source of the lead. Particularly in pregnant women, bone lead release could influence health in pregnancy and be extremely harmful to the rapidly growing and developing fetus. Accordingly, female workers of childbearing age should avoid excessive lead exposure. However, because studies of pregnant workers encounter many difficulties and inconveniences, sufficient research has not been conducted in this area. As an alternative, a group of non-occupationally exposed women, matched as well as possible for anthropometric and reproductive variables and with almost the same levels of blood lead, could be recruited for survey.

Distribution of blood concentrations of persistent organic pollutants in a representative sample of the population of Catalonia

BACKGROUND

Although virtually all populations worldwide are commonly exposed to numerous persistent organic pollutants (POPs) and human concentrations vary widely, only a few countries conduct nationwide surveillance programs of POP concentrations in representative samples of the general population.

OBJECTIVE

To evaluate the distribution of serum concentrations of nineteen POPs and their main predictors in a representative sample of the general population of Catalonia.

METHODS

Participants in the Catalan Health Interview Survey aged 18-74 years were interviewed face-to-face, gave blood, and underwent a physical exam. Graphs (including "POP Geoffrey Rose curves") were used to represent the full population distribution of each POP in the 919 participants. Through multivariate statistical models we analyzed the influence on POP concentrations of sex, age, body mass index (BMI), socioeconomic status and, in women, parity.

RESULTS

We detected dichlorodiphenyltrichloroethane (p,p'-DDT), dichlorodiphenyldichloroethane (p,p'-DDE), polychlorinated biphenyls (PCBs) congeners 118, 138, 153 and 180, hexachlorobenzene (HCB) and beta-hexachlorocyclohexane (beta-HCH) in more than 85% of the subjects. p,p'-DDE, HCB and beta-HCH showed the highest concentrations (median=399, 159 and 92 ng/g lipid, respectively). Distributions were highly skewed and interindividual differences were up to 7700-fold. POP levels differed significantly by gender, age, BMI, educational level, and parity.

CONCLUSIONS

In Catalonia, an advanced European society, exposure to POPs remains common, a vast majority of the population has much lower blood concentrations than a relative minority, and the population distributions of POP are hence highly skewed to the right. Shifting distributions towards lower concentrations requires more energetic policies and population strategies.

Blood total mercury and fish consumption in the Korean general population in KNHANES III, 2005

OBJECTIVES

The objective of this study was to assess the association between the blood total mercury concentration and fish consumption in the Korean general adult population using a representative sample.

METHODS

We studied the blood mercury concentration in a representative sample of 1,749 Koreans who were included in the Third Korean National Health and Nutritional Examination Survey (KNHANES III) performed in 2005, and compared it with the frequency of fish consumption collected during the nutrition survey of KNHANES III.

RESULTS

The geometric means of the blood mercury levels in female subjects (n=890), male subjects (n=859), and all participants (n=1,749) representing adult Koreans aged > or =20 years were 3.70 microg/L [95% confidence interval (CI), 3.46-3.94 microg/L], 4.70 microg/L (95% CI, 4.38-5.02 microg/L), and 4.15 microg/L (95% CI, 3.93-4.38 microg/L), respectively. The geometric mean of the blood mercury level was significantly higher in the high-fish-consumption group (4.38 microg/L; more than once a week) than in the low-consumption group (3.71 microg/L: less than once a week), but the intergroup difference of 18% was less than that in Western countries. Among the nine listed individual types of fish and shellfish, there was a general trend for the blood mercury level to increase with the consumption frequency of squid, clam, salted seafood, and mackerel. The proportion of Korean women aged 20-49 years having blood mercury levels of at least 5.8 microg/L was 27.7% (150/542) in our study.

CONCLUSIONS

The blood mercury level in a representative sample of the Korean adult population was found to be associated with fish consumption in both men and women. However, a high consumption of fish increased the blood mercury level by only 18%.

Cadmium in animal production and its potential hazard on Beijing and Fuxin farmlands

A random sample of pairs of animal feeds and manures were collected from 215 animal barns in Beijing and Fuxin regions of China. The concentrations of Cd in manures and feeds ranged from non-detectable to 129.8 mg/kg dry weight and non-detectable to 31 mg/kg dry weight, respectively. The concentrations of Cd in pig, dairy cow and chicken manures were positively correlated to those in their feeds. About 30% of the manure samples contained Cd concentrations higher than the upper limit for use in farmlands, and pig and chicken manures might be the primary contributors of Cd to farmlands. The farmlands in Beijing and around the Fuxin Downtown areas would exceed the soil quality criteria within several decades according to current manure Cd loading rates. Undoubtedly, more scientific animal production and manure management practices to minimize soil pollution risks are necessary for the two regions.

Identifying sources of lead exposure for children, with lead concentrations and isotope ratios

Despite a dramatic decrease in children's blood lead levels (BLL), lead exposure remains a public health concern because increasing evidence shows effects at very low doses. Lowering BLL still further requires the identification of lead sources and, therefore, new tools to investigate and thus prevent exposure. We describe a procedure that uses both lead concentrations and isotope ratios (IRs) to identify sources of overexposure in homes. Water, dust, and paint chips were sampled from the homes of 21 children with elevated BLL from Aubervilliers (Paris metropolitan area). Lead concentrations of concern were calculated from reverse physiologically based pharmacokinetic modeling for water and dust. Isotope ratio matching of blood and environmental samples (with a lead content above the concentration of concern) was performed by computation of the distance between their IRs. When the IR of the source did not match that of the blood, the source was eliminated as a source of lead intoxication. The number of sources eliminated (per child) due to lead concentration ranged from 14% to 86% (mean 66%) for dust, and 100% for water samples. The number of remaining potential sources eliminated by IR interpretation varied from 0% to 100% for both dust and paint chips (mean 63% and 58%, respectively). IRs made it possible to eliminate at least one source in 20 of 21 cases and identified a single source in 11 of 21. The number of dust and paint sources not eliminated by concentration or IR varied from 8% to 45% (median 18%). The pilot study supports the usefulness of these procedures and the added value of IRs for identifying sources of lead poisoning. However, systematic use should be supported by cost-effectiveness analysis on a larger and more representative population of elevated BLL.

Cytogenetic status in newborns and their parents in Madrid: the BioMadrid study

Monitoring cytogenetic damage is frequently used to assess population exposure to environmental mutagens. The cytokinesis-block micronucleus assay is one of the most widely used methods employed in these studies. In the present study we used this assay to assess the baseline frequency of micronuclei in a healthy population of father-pregnant woman-newborn trios drawn from two Madrid areas. We also investigated the association between micronucleus frequency and specific socioeconomic, environmental, and demographic factors collected by questionnaire. Mercury, arsenic, lead, and cadmium blood levels were measured by atomic absorption spectrometry. The association between micronucleated cell frequency and the variables collected by questionnaire, as well as, the risk associated with the presence of elevated levels of metals in blood, was estimated using Poisson models, taking the number of micronucleated cells in 1,000 binucleated cells (MNBCs) as the dependent variable. Separate analyses were conducted for the 110 newborns, 136 pregnant women, and 134 fathers in whom micronuclei could be assessed. The mean number of micronucleated cells per 1,000 binucleated cells was 3.9, 6.5, and 6.1 respectively. Our results show a statistically significant correlation in MNBC frequency between fathers and mothers, and between parents and newborns. Elevated blood mercury levels in fathers were associated with significantly higher MNBC frequency, compared with fathers who had normal mercury levels (RR:1.21; 95%CI:1.02-1.43). This last result suggests the need to implement greater control over populations which, by reason of their occupation or life style, are among those most exposed to this metal.

The mercury burden of the Czech population: An integrated approach

In this paper an integrated approach in assessment of the population exposure from various sources of total mercury (THg) oral intake in the Czech Republic is presented. The information on total mercury levels in diet, drinking water, surface urban soil and body fluids and tissues stem from the Czech national Environmental Health Monitoring System (EHMS) operated since 1994. The THg concentration was determined by the special atomic absorption spectrophotometer AMA 254. The data on THg content in food from the sales network were collected in 12 cities. The estimated average dietary intake representing more than 95% of weight of usual diet composition ranged 1-2% of the JECFA/FAO WHO provisional tolerable weekly intake (PTWI) value for total mercury (5 microg/kg b.w./week). Data on drinking water quality stem from the nationwide monitoring database. The content of THg in drinking water is generally low; only 0.2% of the Czech population supplied with drinking water from the distribution networks (total of 92% of the population) has a mercury intake from drinking water higher than 1% PTWI and not exceeding 5% PTWI. The estimation of potential mercury intake by unintentional consumption of soil in small children was based on THg content in surface soil of a total of 324 nursery schools in 24 cities and towns. Median value was 0.16 mg/kg. Human biomonitoring was performed in 9 Czech cities. In 2007, the mercury median values in blood of adults (N=412) were 0.85 and 0.89 microg/l in males and in females, respectively; urine median value in adults was 1.10 microg/g creatinine. In 2008, the blood median value in children (N=324) amounted to 0.35 microg/l; urine median value is 0.16 microg/g creatinine. In children's hair the median THg value was 0.18 microg/g. The correlation between fish consumption and blood THg levels was observed in both adults and children. Also the biomonitoring outputs did not reveal a substantial burden of the population.

Mercury exposure and periodontitis among a Korean population: the Shiwha-Banwol environmental health study

BACKGROUND

The oral effect of chronic low-level mercury exposure is not completely understood. This study examined whether mercury exposure is associated with periodontitis.

METHODS

This study cross-sectionally surveyed 1,328 residents (598 males and 730 females) from the prospective Shiwha and Banwol cohort in Korea from July 2005 to August 2006 at baseline. Two dentists assessed periodontitis, an outcome, using the Community Periodontal Index (CPI): CPI 3 or 4 and CPI 0 to 2 were classified as periodontitis and non-periodontitis, respectively. The hair mercury level, the predictor, was analyzed. The mercury level was categorized according to the reference dose of the Environmental Protection Agency of the United States: normal = <1 ppm and high = > or =1 ppm. Age, gender, economic status, smoking, frequency of daily toothbrushing, diabetes mellitus, hyperlipidemia, and obesity were assessed as confounders. Logistic regression analysis was used to evaluate the adjusted association. Subgroup analyses for gender were also performed.

RESULTS

Mercury exposure was independently associated with periodontitis (odds ratio = 3.17). Males with high mercury levels had a 50.0% higher probability of having periodontitis than females with normal mercury levels. Of them, the interaction effect between the body burden of mercury and gender was 39.0%. The odds ratio between periodontitis and high mercury levels was higher for males than females (95% confidence interval: 0.99 to 2.23 versus 0.59 to 1.26, respectively).

CONCLUSIONS

These results suggest that mercury exposure had an independent association with periodontitis. High body-burden mercury in males might be a contributory factor linked with periodontitis.

Health assessment of artisanal gold miners in Indonesia

Small scale miners use mercury to extract gold from ore in many countries. An environmental and health assessment was performed in Indonesia in two regions, Galangan in Central Kalimantan and Talawaan in Northern Sulawesi. The environmental assessment showed severe mercury contamination of the sediments, and increased mercury levels in local fish. For the health investigation 281 volunteers were recruited and examined by a standardized questionnaire, a neurological examination and neuro-psychological tests. A medical score was used consisting of significant factors of mercury intoxication. Mercury exposed workers showed typical symptoms of mercury intoxication, such as movement disorders (ataxia, tremor, dysdiadochokinesia, etc.). Blood, urine and hair samples were taken from any participant and analyzed for mercury. The mercury concentration in the biomonitors was high, partly extreme high in the working population, increased in the population living in the same habitat and low in the control group. By a standard protocol which includes a combination of threshold values of mercury in the biomonitors and a medical sum score the diagnosis of chronic mercury intoxication was made for highly burdened workers (amalgam smelters) in 55% in Sulawesi and in 62% in Kalimantan. Less exposed mineral processors and the general population in the mining areas were also intoxicated to a high percentage.

Heavy metal exposure in patients suffering from electromagnetic hypersensitivity

BACKGROUND

Risks from electromagnetic devices are of considerable concern. Electrohypersensitive (EHS) persons attribute a variety of rather unspecific symptoms to the exposure to electromagnetic fields. The pathophysiology of EHS is unknown and therapy remains a challenge.

OBJECTIVES

Heavy metal load has been discussed as a potential factor in the symptomatology of EHS patients. The main objective of the study was to test the hypothesis of a link between EHS and heavy metal exposure.

METHODS

We measured lead, mercury and cadmium concentrations in the blood of 132 patients (n=42 males and n=90 females) and 101 controls (n=34 males and n=67 females).

RESULTS

Our results show that heavy metal load is of no concern in most cases of EHS but might play a role in exceptional cases.

CONCLUSIONS

The data do not support the general advice to heavy metal detoxification in EHS.

Health assessment of artisanal gold miners in Tanzania

In 2003 UNIDO (United Nations Industrial Development Organization) conducted an environmental and health assessment in a small-scale mining area in Tanzania. BGS (British Geological Survey) performed the environmental assessment. The Institute of Forensic Medicine - University of Munich performed the health assessment. The results of the medical, neurological and neuro-psychological examination of 180 participants from the affected area of Rwamagasa and 31 controls were analyzed. Urine, blood and hair samples were analyzed to detect the level of mercury body burden. Mercury concentrations in the bio-monitors urine, blood and hair were statistically significantly higher in the exposed population from Rwamagasa compared to the control group from Katoro. Only amalgam burners showed mercury levels above the toxicological threshold limits. A speciation of mercury in hair indicated that mainly elemental mercury vapor contributed to the high body burden of the artisanal miners. 104 amalgam-burners, the most exposed population group, were examined. 25 of these workers were found to be intoxicated. Small-scale mining is a serious health hazard for amalgam burners. Reduction of the exposure is essential to prevent further damage.

GerES IV: phthalate metabolites and bisphenol A in urine of German children

Urine samples from GerES IV were analysed for concentrations of the metabolites of DEHP (MEHP, 5OH-MEHP, 5oxo-MEHP, 5cx-MEPP, and 2cx-MMHP), DnBP and DiBP (MnBP and MiBP), BBzP (MBzP), DiNP (7OH-MMeOP, 7oxo-MMeOP and 7cx-MMeHP), and bisphenol A (BPA) to assess the exposure of German children on a representative basis. 600 morning urine samples had been randomly chosen from stored 1800 GerES IV samples originating from 3 to 14 year old children living in Germany. All metabolites could be detected in nearly all urine samples (N=599). Descriptive data analysis leads to mean concentrations of 5-OH-MEHP and 5-oxo-MEHP of 48microg/l and 37microg/l, respectively. The mean concentration of 7OH-MMeOP was 11microg/l. MnBP, MiNP, MBzP showed mean levels of 96microg/l, 94microg/l, and 18microg/l, respectively. The concentrations of the phthalate metabolites decreased with increasing age. Compared to German adults all children showed three to five fold higher urine concentrations than adults analysed in the same decade. For some children the levels of the sum of 5OH-MEHP and 5oxo-MEHP in urine were higher than the German human biomonitoring value (HBM I) of 500mcirog/l, which indicates that adverse health effects cannot be excluded for these subjects with sufficient certainty. The mean concentration of BPA in urine was 2.7microg/l. A rough calculation of the daily intakes on the basis of the measured concentrations in urine resulted in daily intakes two orders of magnitude lower than the current EFSA reference dose of 50microg/kgbw/d.

Sociodemographic factors influencing participation in the Barcelona Health Survey study on serum concentrations of persistent organic pollutants

BACKGROUND

Little is known about factors affecting participation in population-based biomonitoring studies. We analyzed socioeconomic factors influencing participation in the Barcelona Health Survey (BHS) study on the distribution of serum concentrations of persistent organic pollutants (POPs).

METHODS

After completing the BHS personal interview at home participants aged >or=15 years were invited to donate blood. Conducted on a different date and location, the POPs study included additional questions, blood extraction, and a brief physical examination. Factors influencing participation were analyzed by logistic regression.

RESULTS

Of 523 BHS participants that we contacted to participate in the study, 231 (44%) participated; they were broadly representative of the city population regarding sex, birth place, body mass index (BMI), employment status and occupational social class. Participants in the POPs study had higher educational level and family income. Controlling for confounders, participation was slightly higher among women than men (odds ratio [OR]=1.38, p=0.02), and lower among the youngest and oldest subjects (p=0.002), with a strong and monotonic trend of increasing participation with increasing educational level (p<0.001) (OR for university level vs. no studies=4.58, 95% CI: 2.3-9.3).

CONCLUSIONS

Although participation was somewhat low, participants were similar to the city population regarding sex, BMI, birth place, employment, and occupational social class. Health surveys that integrate environmental biomarkers should invest specific resources to encourage participation of the youngest and oldest individuals, and of those with more disadvantaged socioeconomic position (particularly, citizens with lowest education).

Total blood mercury concentrations in the U.S. population: 1999-2006

We describe the distribution and demographic characteristics of total blood Hg levels in the U.S. general population among persons ages 1 year and older who participated in the 2003-2006 National Health and Nutrition Examination Survey (NHANES). We also describe trends in the total blood Hg of children ages 1-5 (n=3456) and females ages 16-49 during 1999-2006 (n=7245). In the combined 2003-2006 survey periods, the geometric means for non-Hispanic blacks, 0.853microg/L (95% confidence interval [CI], 0.766-0.950microg/L), and non-Hispanic whites, 0.833microg/L (95% CI, 0.752-0.922microg/L), were higher than the geometric mean for Mexican Americans, 0.580microg/L (95% CI, 0.522-0.645microg/L). Also in 2003-2006, regression analysis of log total blood Hg with age, race/ethnicity and gender showed that total blood Hg levels in the population exhibited a quadratic increase with age (p<0.0001), peaking at ages 50-59 in non-Hispanic blacks and whites, at ages 40-49 in Mexican Americans, and then declining at older ages. Over the four survey periods (1999-2006), regression analysis showed that total blood Hg levels increased slightly for non-Hispanic white children and decreased slightly for non-Hispanic black and Mexican American children. Over the same four survey periods, female children had slightly higher total blood Hg levels than males (0.356 vs. 0.313microg/L, p=0.0050) and total blood Hg levels in non-Hispanic black women aged 16-49 years were significantly higher than in non-Hispanic white women (1.081 vs. 0.850microg/L, p<0.0001) and in Mexican American women (1.081 vs. 0.70microg/L, p<0.0001).

A review on the practical application of human biomonitoring in integrated environmental health impact assessment

Environmental health sciences focus on the link between the presence of contaminants in the environment and their relation with possible adverse health effects. Within this context, human biomonitoring (HBM) data have proven to be a valuable addition to, or have even surpassed, estimates of exposure based on environmental measures. Probably the main achievement of HBM data is that it provides an integrated overview of the pollutant dose any constituent is exposed to and incorporates bioaccumulation, excretion, half-life, and other potentially critical toxicokinetic parameters. In an integrated environmental health impact assessment framework, HBM serves as a pivotal point between environment and health, on the one hand leaning on environmental data to provide information on sources and pathways of exposure, and on the other hand clarifying hypotheses on the relationship between internal dose and prevalence of disease clusters. This study reflects the work performed in the INTARESE project (Integrated Assessment of Health Risk of Environmental Stressors in Europe). Because it was perceived that there was an overall lack of knowledge on the general methodology and potential application of HBM data in integrated environmental health impact assessment, an extensive review of literature was performed on past and current developments, potential, and applicability of HBM within the context of integrated environmental health impact assessment. This study covers three main topics that provide guidance for improved interpretation and application of HBM data: (1) sample collection and storage, (2) sample measurement, and (3) data interpretation. These main issues were discussed for 15 of the most common or relevant (classes of) chemicals. For more detailed information, the reader is pointed to the unabridged review (INTARESE, 2007), and consultation is available through the INTARESE web site (www.intarese.org).

Human health effects of methylmercury exposure

Mercury (Hg), and the organometallic compounds formed from it, are among the most toxic of substances to the global environment. Mercury is environmentally ubiquitous, and both wildlife and humans are exposed to the toxic effects of its environmental residues, primarily elemental mercury (Hg0), divalent mercury (Hg2+) and methylmercury (MeHg). Humans are exposed to different forms of Hg, and potential health risks have been reported from such exposures; examples of Hg exposure include mercury vapor from dental amalgams, occupational exposures and exposures during artisan and small-scale gold mining operations. Despite the significance of those foregoing Hg exposures, of particular concern is human and wildlife exposure to MeHg, a potent neurotoxicant. Once incorporated into the body, MeHg easily penetrates the blood-brain barrier and causes damage to the central nervous system, particularly in fetuses. It bioaacumulates and biomagnifies in the aquatic food chain; consequently, fish and seafood consumption is the major pathway by which humans are exposed to MeHg. MeHg is the focus of this review. It adversely affects humans and is currently the subject of intense public health interest and worldwide concern. In this review, I summarize the sources and cycling of global mercury in the environment, pathways of exposure, toxicity and exposure evaluation, toxicokinetics, the common biomarkers to evaluate exposure and effects in populations, and finally review the nutritional risks and benefits from fish consumption.

Comments on the Article “The Toxicology of Mercury and Its Chemical Compounds” by Clarkson and Magos (2006)

Clarkson and Magos (2006) provide their perspectives on the toxicology of mercury vapor and dental amalgam. As scientists who are involved in preparing a German federal guideline regarding dental amalgam, we welcome additional scientific data on this issue. However, Clarkson and Magos do not present all the relevant studies in their review. The additional data provided here show that: (a) Dental amalgam is the main source of human total mercury body burden, because individuals with amalgam have 2-12 times more mercury in their body tissues compared to individuals without amalgam; (b) there is not necessarily a correlation between mercury levels in blood, urine, or hair and in body tissues, and none of the parameters correlate with severity of symptoms; (c) the half-life of mercury deposits in brain and bone tissues could last from several years to decades, and thus mercury accumulates over time of exposure; (d) mercury, in particular mercury vapor, is known to be the most toxic nonradioactive element, and is toxic even in very low doses, and (e) some studies which conclude that amalgam fillings are safe for human beings have important methodogical flaws. Therefore, they have no value for assessing the safety of amalgam.

Translating biomonitoring data into risk management and policy implementation options for a European Network on Human Biomonitoring

BACKGROUND

The "European Environment & Health Action Plan 2004-2010" originates from the concern of the European Commission on the well-being of individuals and the general population. Through this plan, the Commission has set the objectives to improve the information chain for a better understanding of the link between sources of pollution and health effects, to better identify existing knowledge gaps, and improve policy making and communication strategies. Human biomonitoring (HBM) has been included as one of the tools to achieve these objectives. As HBM directly measures the amount of a chemical substance in a person's body, taking into account often poorly understood processes such as bioaccumulation, excretion, metabolism and the integrative uptake variability through different exposure pathways, HBM data are much more relevant for risk assessment than extrapolations from chemical concentrations in soil, air, and water alone. However, HBM primarily is a stepping stone between environmental and health data, and the final aim should be an integrated and holistic systematic risk assessment paradigm where HBM serves as a pivotal point between environment and health, on the one hand leaning on environmental data to provide detailed information on the sources and pathways of pollutants that enter the human body, and on the other hand clarifying new and existing hypotheses on the relationship between environmental pollutants and the prevalence of diseases. With the large amount of data that is being gathered in the different national survey projects, and which is expected to become available in Europe in the near future through the expected European Pilot Project on HBM, a framework to optimize data interpretation from such survey projects may greatly enhance the usefulness of HBM data for risk managers and policy makers.

RESULTS

This paper outlines an hierarchic approach, based on the stepwise formulation of 4 subsequent steps, that will eventually lead to the formulation of a variety of policy relevant risk reduction options.

CONCLUSION

Although the usefulness of this approach still needs to be tested, and potential fine-tuning of the procedure may be necessary, approaching the policy implications of HBM in an objective framework will prove to be essential.

Uptake of cadmium from Pacific oysters (Crassostrea gigas) in British Columbia oyster growers

BACKGROUND

Pacific oysters along the North American coast from Washington to Alaska contain concentrations of cadmium (Cd) that are high by comparison with Atlantic oysters, frequently exceeding 2mug/g wet weight, but it is unclear whether this Cd is absorbed by consumers.

OBJECTIVES

To determine the effect of oyster consumption on Cd in blood and urine among a group with high oyster consumption.

METHODS

Sixty-one non-smoking oyster growers and family members with a mean age of 47.3+/-7.6 years (range 33-64) were interviewed by telephone to assess their oyster consumption and other sources of Cd exposure at present and 5 years prior to the start of oyster farming. Their blood and urine Cd concentrations were measured.

RESULTS

The geometric mean Cd concentration in blood was 0.83mug/L and in urine was 0.76mug/g creatinine. Thirty-six percent of participants had urinary Cd levels above 1mug/g creatinine and 5% were above 2mug/g creatinine. Recent (last 12 months) and long-term oyster consumptions were positive predictors of blood Cd but did not directly predict urinary Cd. The optimal model for predicting the variance in blood Cd included recent intake of oyster-derived Cd, serum iron concentration and recent ketchup consumption (R(2)=0.34, p=0.00004), with the latter two variables showing a protective effect. The factors found to predict urinary Cd were blood Cd concentration and duration of oyster farming. A rise in blood Cd was observed after 12 years of farming oysters, likely caused by higher consumption of oysters during this period.

CONCLUSIONS

Oyster-derived Cd is bioavailable and affects body stores of the metal.

Monitoring concentrations of persistent organic pollutants in the general population: the international experience

Assessing the adverse effects on human health of persistent organic pollutants (POPs) and the impact of policies aiming to reduce human exposure to POPs warrants monitoring body concentrations of POPs in representative samples of subjects. While numerous ad hoc studies are being conducted to understand POPs effects, only a few countries are conducting nationwide surveillance programs of human concentrations of POPs, and even less countries do so in representative samples of the general population. We tried to identify all studies worldwide that analyzed the distribution of concentrations of POPs in a representative sample of the general population, and we synthesized the studies' main characteristics, as design, population, and chemicals analyzed. The most comprehensive studies are the National Reports on Human Exposure to Environmental Chemicals (USA), the German Environmental Survey, and the Arctic Monitoring and Assessment Programme. Population-wide studies exist as well in New Zealand, Australia, Japan, Flanders (Belgium) and the Canary Islands (Spain). Most such studies are linked with health surveys, which is a highly-relevant additional strength. Only the German and Flemish studies analyzed POPs by educational level, while studies in the USA offer results by ethnic group. The full distribution of POPs concentrations is unknown in many countries. Knowledge gaps include also the interplay of age, gender, period and cohort effects on the prevalence of exposures observed by cross-sectional surveys. Local and global efforts to minimize POPs contamination, like the Stockholm convention, warrant nationwide monitoring of concentrations of POPs in representative samples of the general population. Results of this review show how such studies may be developed and used.

Trace element composition of plasma and breast milk of well-nourished women

A wide variation in the composition of breast milk has been reported from various countries. This study was undertaken to determine the trace element content of breast milk and plasma in lactating women. Mothers of children 4 weeks to 80 weeks in age, were studied. Blood and breast milk from the mothers were analysed for trace element content. Prepared samples were analysed using ICP-MS. 209 women agreed to take part in the study, 68 of whom were from the UAE and 124 were other nationalities (17 did not fill the this part of the questionnaire). Ninety-seven infants were male. The concentration of different trace elements in blood and breast milk were little different between women from the UAE and those from outside the UAE. Molybenum, chromium and arsenic significantly increased with increasing age of the infant, while manganese, copper and zinc significantly decreased with increasing age of the infant. The trace element concentrations of breast milk and maternal blood were comparable to published values. Normal values for plasma and breast milk trace metal concentrations have been obtained for UAE women.

Trace element levels in adults from the west coast of Canada and associations with age, gender, diet, activities, and levels of other trace elements

The purpose of this study was to assess trace element levels in whole blood, serum and urine of 61 non-smoking adults living on the west coast of Canada and to determine their association with the following variables: age, gender, diet, participation in certain hobby and/or occupational activities, and levels of other trace elements. Participants or their spouses were employed as oyster growers and were originally recruited to study the absorption of cadmium from oyster consumption. Trace elements were measured using inductively-coupled plasma mass spectrometry. A telephone interview was used to assess participant's intake of selected foods and the amount of time they have spent on certain activities over the lifetime. Comparison of results to previous studies revealed that blood lead, blood mercury, serum nickel, serum selenium and urine molybdenum levels were generally higher in this study than have previously been measured, possibly due to higher consumption of seafood in this sample. Men had statistically higher levels of serum iron, blood lead, and serum selenium, while women had statistically higher levels of serum copper and blood manganese. Blood lead levels increased with age. Diet had a statistically significant association with several elements. Consumption of spinach, seaweed, organ meats, and shellfish tended to be positively correlated with trace element concentrations and consumption of various forms of potatoes tended to be negatively correlated. Several statistically significant correlations were also observed between trace elements.

German Environmental Survey for Children (GerES IV) – First results

German Environmental Surveys (GerESs) are large scale population studies which have been carried out on adults in 1985/86, 1990/92 and 1998 and on children aged 6-14 years in 1990/92. GerES IV is the first survey focussing exclusively on children [Becker, K., Schulz, C., Babisch, W., Dürkop, J., Roskamp, E., Seiwert, M., Szewzyk, R., Ullrich, D., Seifert, B., 2005. German Environmental Survey for Children (GerES IV) 2003-2006. Pullut. Atmos. 188, 475-479]. GerES IV included a representative sample of 1790 children aged 3-14 of the participants of the National Health Interview and Examination Survey on Children and Adolescents. The primary goal of GerES IV is not only to analyse and document the extent, distribution and determinants of German children's exposure to environmental pollutants but to discover links between environmental exposure and health. Results will help develop preventive measures and advance further research. They might provide the basis for environmental and public health policy decisions. Precondition to achieve this task is a description of the data on exposures and the data on health outcomes. This work is currently performed at the Federal Environment Agency. First results show a remarkable decrease of the blood lead level of German children aged 6-14 years from 32.3 microg/l in 1990/92 (GerES II) to 16.3 microg/l in GerES IV which is the lowest mean lead concentration determined in German studies so far. None of the children had a value exceeding 100 microg/l. In GerES IV, the following health-related issues will be primarily examined: the relationship between sensitisation against mould spores and the occurrence of mould in households, irritation of eyes and respiratory system caused by formaldehyde, other aldehydes, or total volatile organic compounds (TVOC); the impact of non-occupational noise on hearing loss, stress and sleep disturbances, and the connection between contact allergies, nickel and scents. 9.5% of the children showed a sensitisation to at least one of the moulds examined (Penicillium (notatum) chrysogenum, Aspergillus versicolor, Wallemia sebi, Eurotium spp., Alternaria alternata). The most frequent sensitisation was against Penicillium chrysogenum. GerES IV might broaden the knowledge in terms of environmental causes of health outcomes. Children of smoking mothers showed higher mean cotinine concentrations than children living with a smoking father, regardless whether they smoked daily or occasionally. Results from the GerES IV pilot study showed a relation between environmental tobacco smoke (ETS) exposure and an increased susceptibility to infections and inflammations of the middle ear.

Child poverty and environmental justice

BACKGROUND

Child poverty and social inequality in Western countries are growing both in scope and in complexity. The clustering of income poverty in urban settings reflects the complex process of residential segregation. Living in segregated neighbourhoods with much poverty and predominantly substandard housing is usually associated with poor physical, chemical and social environmental living conditions at the individual and community level which influence and shape children's health both directly and indirectly.

OBJECTIVE

This paper shows research data on the link between child poverty and income-related health inequalities according to the unequal exposure to environmental hazards as well as the unequal distribution of environmental resources in the domestic environment and within the local context as an increasing public health issue in Germany. The links between these factors are drawn from the conceptual framework of environmental justice. Examples are shown of integrated approaches to alleviate social and environmental disparities at the community level.

CONCLUSION

The implications of environmental justice for public health include the need to uncover the link between socioeconomic factors and environmental health disparities related to the man-made environment. Developing relevant indicators for environmental inequalities in the context of housing and health is an important task for public health research. More emphasis should be placed on a comprehensive holistic approach to understand the mechanisms by which socioeconomic factors modify children's susceptibility and exposure to environmental hazards, particularly in low-income areas.

Human biomonitoring: State of the art

Human biomonitoring (HBM) of dose and biochemical effect nowadays has tremendous utility providing an efficient and cost effective means of measuring human exposure to chemical substances. HBM considers all routes of uptake and all sources which are relevant making it an ideal instrument for risk assessment and risk management. HBM can identify new chemical exposures, trends and changes in exposure, establish distribution of exposure among the general population, identify vulnerable groups and populations with higher exposures and identify environmental risks at specific contaminated sites with relatively low expenditure. The sensitivity of HBM methods moreover enables the elucidation of human metabolism and toxic mechanisms of the pollutants. So, HBM is a tool for scientists as well as for policy makers. Blood and urine are by far the most approved matrices. HBM can be done for most chemical substances which are in the focus of the worldwide discussion of environmental medicine. This especially applies for metals, PAH, phthalates, dioxins, pesticides, as well as for aromatic amines, perfluorinated chemicals, environmental tobacco smoke and volatile organic compounds. Protein adducts, especially Hb-adducts, as surrogates of DNA adducts measuring exposure as well as biochemical effect very specifically and sensitively are a still better means to estimate cancer risk than measuring genotoxic substances and their metabolites in human body fluids. Using very sophisticated but nevertheless routinely applicable analytical procedures Hb-adducts of alkylating agents, aromatic amines and nitro aromatic compounds are determined routinely today. To extend the spectrum of biochemical effect monitoring further methods should be elaborated which put up with cleavage and separation of the adducted protein molecules as a measure of sample preparation. This way all sites of adduction as well as further proteins, like serum albumin could be used for HBM. DNA-adducts indicate the mutagenicity of a chemical substance as well as an elevated cancer risk. DNA-adducts therefore would be ideal parameters for HBM. Though there are very sensitive techniques for DNA adduct monitoring like P32-postlabelling and immunological methods they lack specificity. For elucidating the mechanism of carcinogenesis and for a broad applicability and comparability in epidemiological studies analytical methods must be elaborated which are strictly specific for the chemical structure of the DNA-adduct. Current analytical possibilities however meet their borders. In HBM studies with exposure to genotoxic chemicals especially the measurement of DNA strand breaks in lymphocytes and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in white blood cells has become very popular. However, there is still a lack of well-established dose-response relations between occupational or environmental exposures and the induction of 8-OHdG or formation of strand breaks which limits the applicability of these markers. Most of the biomarkers used in population studies are covered by standard operating procedures (SOPs) as well as by internal and external quality assessment schemes. Therefore, HBM results from the leading laboratories worldwide are analytically reliable and comparable. Newly upcoming substances of environmental relevance like perfluorinated compounds can rapidly be assessed in body fluids because there are very powerful laboratories which are able to elaborate the analytical prerequisites in due time. On the other hand, it is getting more and more difficult for the laboratories to keep up with a progress in instrumental analyses. In spite of this it will pay to reach the ultimate summit of HBM because it is the only way to identify and quantify human exposure and risk, elucidate the mechanism of toxic effects and to ultimately decide if measures have to be taken to reduce exposure. Risk assessment and risk management without HBM lead to wrong risk estimates and cause inadequate measures. In some countries like in USA and in Germany, thousands of inhabitants are regularly investigated with respect to their internal exposure to a broad range of environmentally occurring substances. For the evaluation of HBM results the German HBM Commission elaborates reference- and HBM-values.

Gender differences in the disposition and toxicity of metals

There is increasing evidence that health effects of toxic metals differ in prevalence or are manifested differently in men and women. However, the database is small. The present work aims at evaluating gender differences in the health effects of cadmium, nickel, lead, mercury and arsenic. There is a markedly higher prevalence of nickel-induced allergy and hand eczema in women compared to men, mainly due to differences in exposure. Cadmium retention is generally higher in women than in men, and the severe cadmium-induced Itai-itai disease was mainly a woman's disease. Gender differences in susceptibility at lower exposure are uncertain, but recent data indicate that cadmium has estrogenic effects and affect female offspring. Men generally have higher blood lead levels than women. Lead accumulates in bone and increased endogenous lead exposure has been demonstrated during periods of increased bone turnover, particularly in women in pregnancy and menopause. Lead and mercury, in the form of mercury vapor and methylmercury, are easily transferred from the pregnant women to the fetus. Recent data indicate that boys are more susceptible to neurotoxic effects of lead and methylmercury following exposure early in life, while experimental data suggest that females are more susceptible to immunotoxic effects of lead. Certain gender differences in the biotransformation of arsenic by methylation have been reported, and men seem to be more affected by arsenic-related skin effect than women. Experimental studies indicate major gender differences in arsenic-induced cancer. Obviously, research on gender-related differences in health effects caused by metals needs considerable more focus in the future.

German Environmental Survey (GerES): Human biomonitoring as a tool to identify exposure pathways

The German Environmental Survey (GerES) is a representative population study and has been repeatedly carried out since the mid-1980s. The currently run survey (GerES IV) is the first one solely targeted on children. The GerES IV Pilot Study resulted in first insights into major exposure pathways relevant to children. These insights were made possible by the determination of pollutant concentrations in blood and urine and the additional consideration of their occurrence in the indoor environment and by using questionnaire data. The results of the GerES IV Pilot Study are presented according to major exposure pathways such as house dust, food and environmental tobacco smoke (ETS). An overview on relevant pilot study results is given. The results of GerES IV will permit the verification and substantiation of the pilot study results.

Integrated Exposure Assessment Survey (INES)

The Integrated Exposure Assessment Survey (INES) was started in the year 2005. Altogether 50 healthy adults living in Bavaria, Germany, were included into the study. Monitoring was conducted in accordance with relevant routes of human exposure (inhalation, ingestion) and integrated different pathways (indoor air, food, house dust). This approach consisted of a combination of external measurements of contaminants with the determination of these substances or their metabolites in body fluids. The target substances were phthalates, perfluorinated compounds (PFC), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), and polybrominated diphenylethers (PBDEs). This paper gives a brief description of the objectives and the concept of INES as well as methods of sampling and analyses of target compounds. Some preliminary results of biomonitoring data for PFC and phthalates as well as of the dietary intake of DEHP will be discussed.

Twenty years of the German Environmental Survey (GerES): Human biomonitoring – Temporal and spatial (West Germany/East Germany) differences in population exposure

The German Environmental Surveys (GerESs) are nationwide population studies, which have repeatedly been carried out in Germany since the mid-1980s. The subjects were representatively selected from the regional registration offices with regard to age, gender and community size. The first survey for adults (GerES I) was carried out in 1985/1986 (West Germany) followed by GerES IIa in 1990/1991 (West Germany) and GerES IIb in 1991/1992 (East Germany). In GerES II children were also included to some extent. In 1998, the third GerES for adults was conducted in both parts of Germany (GerES III). The current survey 2003/2006 (GerES IV) is focussing exclusively on children. A 1-year pilot study was conducted in 2001-2002 to collect information on parameters influencing the response rate and to test the suitability of the different instruments intended to be used for the main study. The main goal of the surveys is to analyse and document the extent, distribution and determinants of exposure to environmental pollutants of the German general population. Three main instruments of investigation were comprised in GerES: human biomonitoring (HBM), monitoring of the domestic environment, and collecting information on exposure pathways and living conditions via questionnaires. This paper is focussed on the general design of the GerESs, the trend over time and spatial differences (West Germany and East Germany) for HBM data on arsenic, cadmium, lead, mercury, pentachlorophenol (PCP), and polycyclic aromatic hydrocarbons (PAH). These substances have been determined in blood and/or morning urine of adults and children. All GerESs have been conducted in close connection with the National Health Interview and Examination Surveys performed by the Robert Koch-Institute, Berlin.

Mercury exposure and public health

Mercury is a metal that is a liquid at room temperature. Mercury has a long and interesting history deriving from its use in medicine and industry, with the resultant toxicity produced. In high enough doses, all forms of mercury can produce toxicity. The most devastating tragedies related to mercury toxicity in recent history include Minamata Bay and Niagata, Japan in the 1950s, and Iraq in the 1970s. More recent mercury toxicity issues include the extreme toxicity of the dimethylmercury compound noted in 1998, the possible toxicity related to dental amalgams, and the disproved relationship between vaccines and autism related to the presence of the mercury-containing preservative, thimerosal.

Baden-Wuerttemberg Environmental Health Survey (BW-EHS) from 1996 to 2003: toxic metals in blood and urine of children

The environmental health surveillance system in the Federal State of Baden-Wuerttemberg (South Germany), among others, was implemented to monitor pollutant exposures and their temporal and regional trends in children at the age of about 10 years. The investigations were performed in two larger cities, one small city and one rural area. Between 1996 and 2003, in total 5470 children were investigated in consideration of environmental health parameters in four cross-sectional studies. The data presented here cover the results of the determination of the internal load with toxic metals. The median values observed in the investigation in 2002/03 were: 4.6 microg/l urine for arsenic, less than 0.2 microg/l urine for mercury, 20.7 microg/l blood for lead, and 0.25 microg/l blood for cadmium. From 1996 to 2003, mercury concentrations showed a substantial decrease (-0.027 microg/l/year) and lead levels also decreased (-0.25 microg/l/year), whereas arsenic and cadmium levels did not change significantly over time. There was no consistent difference in the mean internal load of the metals between the four investigation areas. Important factors influencing the measured concentrations were consumption of fish in the last 48 h, which had an impact on arsenic (factor 2), and amalgam fillings, which accounted for an increase in mercury (factor 4.6). In the 2002/03 study period, levels above the limit of health concern for children (German HBM values) were found in about 0.5% of the lead measurements (maximum value 180 microg/l blood) and in about 0.2% of the mercury measurements (maximum value 8.2 microg/l urine). In conclusion, this environmental health survey generates objective data on secular trends and regional differences and provides insight into probable sources of toxic metal exposure in children.

The German Human Biomonitoring Commission

In Germany, the Human Biomonitoring Commission of the German Federal Environment Agency was established in 1992 to develop scientifically based criteria for the application of human biomonitoring (HBM). The goal is to clarify fundamental and practical issues related to HBM. Following the assessment of pollutants in body fluids, the commission derives two different kinds of guideline values: reference values and HBM values (HBM I and HBM II values). This article gives a review of the current reference values, HBM values, and the work of the German Human Biomonitoring Commission.

Methylmercury exposure and health effects in humans: a worldwide concern

The paper builds on existing literature, highlighting current understanding and identifying unresolved issues about MeHg exposure, health effects, and risk assessment, and concludes with a consensus statement. Methylmercury is a potent toxin, bioaccumulated and concentrated through the aquatic food chain, placing at risk people, throughout the globe and across the socioeconomic spectrum, who consume predatory fish or for whom fish is a dietary mainstay. Methylmercury developmental neurotoxicity has constituted the basis for risk assessments and public health policies. Despite gaps in our knowledge on new bioindicators of exposure, factors that influence MeHg uptake and toxicity, toxicokinetics, neurologic and cardiovascular effects in adult populations, and the nutritional benefits and risks from the large number of marine and freshwater fish and fish-eating species, the panel concluded that to preserve human health, all efforts need to be made to reduce and eliminate sources of exposure.

Environmental hazards: evidence for effects on child health

The human fetus, child, and adult may experience adverse health outcomes from parental or childhood exposures to environmental toxicants. The fetus and infant are especially vulnerable to toxicants that disrupt developmental processes during relatively narrow time windows. This review summarizes knowledge of associations between child health and development outcomes and environmental exposures, including lead, methylmercury, polychlorinated biphenyls (PCBs), dioxins and related polyhalogenated aromatic hydrocarbons (PHAHs), certain pesticides, environmental tobacco smoke (ETS), aeroallergens, ambient air toxicants (especially particulate matter [PM] and ozone), chlorination disinfection by-products (DBPs), sunlight, power-frequency magnetic fields, radiofrequency (RF) radiation, residential proximity to hazardous waste disposal sites, and solvents. The adverse health effects linked to such exposures include fetal death, birth defects, being small for gestational age (SGA), preterm birth, clinically overt cognitive, neurologic, and behavioral abnormalities, subtle neuropsychologic deficits, childhood cancer, asthma, other respiratory diseases, and acute poisoning. Some environmental toxicants, notably lead, ionizing radiation, ETS, and certain ambient air toxicants, produce adverse health effects at relatively low exposure levels during fetal or child developmental time windows. For the many associations supported by limited or inadequate epidemiologic evidence, major sources of uncertainty include the limited number of studies conducted on specific exposure-outcome relationships and methodologic limitations. The latter include (1) crude exposure indices, (2) limited range of exposure levels, (3) small sample sizes, and (4) limited knowledge and control of potential confounders. Important knowledge gaps include the role of preconceptual paternal exposures, a topic much less studied than maternal or childhood exposures. Large longitudinal studies beginning before or during early pregnancy are urgently needed to accurately measure and assess the relative importance of parental and childhood exposures and evaluate relatively subtle health outcomes such as neuropsychologic and other functional deficits. Large case-control studies are also needed to assess the role of environmental exposures and their interactions with genetic factors in relatively uncommon outcomes such as specific types of birth defects and childhood cancers. There is also an urgent need to accelerate development and use of biomarkers of exposure and genetic susceptibility in epidemiologic studies. This review supports the priority assigned by international agencies to relationships between child health and air quality (indoor and outdoor), lead, pesticides, water contaminants, and ETS. To adequately address such priorities, governments and agencies must strengthen environmental health research capacities and adopt policies to reduce parental and childhood exposures to proven and emerging environmental threats.

Whole blood mercury and selenium concentrations in a selected Austrian population: does gender matter?

BACKGROUND

Data on mercury exposure of the Austrian population were inadequate. This study was performed to determine the causal factors underlying mercury exposure and selenium concentrations, and to estimate the gender-related health impacts.

METHODOLOGY

Venous blood samples of 78 women and 81 men were drawn at the Austrian Red Cross, Vienna. Mercury contents in acid-digested whole blood samples were measured after amalgam enrichment by CV-AAS, and selenium by AAS (heated quartz-cell) after hydrid formation.

RESULTS

The average total mercury blood content of Austrians was low (2.38+/-1.55 microgL(-1); N=152). Mercury and selenium concentrations were not different between the genders (P>0.05) but we observed discrepancies regarding the causal factors. Mercury levels in men were influenced not only by fish consumption but also by age, education level, and amalgam fillings, whereas in women, only the diet (fish/seafood, red wine consumption) determined blood mercury (P<0.05). Moreover, only the males indicated a depressive effect of dental amalgam on hematocrit (P<0.05). Regarding selenium, age and alcohol consumption led to lower concentrations in men, whereas a high-level education had the opposite effect; no determinant was found for women. For the whole study group, a significant effect of chronic disease on selenium levels could be detected (P<0.05). 18% of women and 13% of men showed marginal selenium deficiency (blood selenium<65 microgL(-1)). Selenium and mercury concentrations were not correlated.

CONCLUSIONS

Our results indicate the need to evaluate and integrate gender-related findings in metal toxicology and trace element research, because different causal factors require different preventive measures to reduce mercury exposure and the risk of low selenium concentrations. Future research is needed on the gender- and age-related differences in fish/seafood consumption habits, the modifications of mercury toxicokinetics through sex hormones, the selenium supply in Austria, and the clinical relevance of a low selenium status.

Blood and urine levels of Pb, Cd and Hg in the general population of the Czech Republic and proposed reference values

The Human Biological Monitoring (HBM) project was launched in the Czech Republic in 1994 as a part of the nation-wide Environmental Health Monitoring System to assess the exposure of the Czech general population to a broad spectrum of environmental contaminants. Over the years 2001-2003, the concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) were determined in whole blood of 1188 adults (blood donors) and 333 children and in urine of 657 adults and 619 children. In adults, the median blood lead (B-Pb) level was 33microg/l. Men had higher B-Pb levels than women (medians 37microg/l vs. 25microg/l). Significantly higher B-Pb levels were observed in smokers compared to non-smokers (36microg/l vs. 31microg/l). In children, no sex-dependent differences were observed (median 31microg/l). In total, the median blood Cd level (B-Cd) in adults was 0.5microg/l. Smokers showed a median B-Cd level about 3 times as high as non-smokers (1.3microg/l vs. 0.40microg/l). Neither sex- nor age-related differences were observed in B-Cd levels. In 65% of children, B-Cd levels were below the limit of detection (LOD). The overall median urinary cadmium level (U-Cd) in adults was 0.31microg/g creatinine. Significantly higher U-Cd levels were found in women (median 0.39microg/g creatinine) compared to men (0.29microg/g creatinine). No significant differences were found between smokers and non-smokers. In more than 50% of children, the U-Cd level was below the LOD (=0.2microg/l). The median blood mercury (B-Hg) level in adults was 0.89microg/l. Significant differences were found between smokers (0.80microg/l) and non-smokers (0.92microg/l), and between men and women (0.86microg/l vs. 0.94microg/l). The median B-Hg level in children was 0.42microg/l and no sex-related differences were observed. The median urinary mercury (U-Hg) levels were 0.63microg/g creatinine in adults and 0.37microg/g creatinine in children. Significantly higher U-Hg levels were obtained in women and non-smokers compared to men and smokers, respectively. The B-Pb, B-Hg, U-Cd, and U-Hg levels significantly correlated with age. The following reference values were recommended for the period 2001-2003: 80, 65 and 55microg/l for B-Pb and 3.1, 4.0 and 1.5microg/l for B-Hg in men, women and children, respectively; 1.1microg/l and 1.2microg/g creatinine for B-Cd and U-Cd, respectively, in adult non-smokers; 5.4 and 12.0microg/g creatinine for U-Hg in men and women, respectively, and 3.7 and 5.5microg/g creatinine for U-Hg in boys and girls, respectively. The previous reference values for B-Pb and B-Cd needed revision and were reduced.

Are there sex and gender differences in acute exposure to chemicals in the same setting?

We have little understanding of the influence that sex and gender may have on exposure to and measurement of occupational chemicals. If men and women are in the same physical environment, whether that be an occupational or an environmental setting, researchers need to question whether their acute exposure, as measured by administered and/or biologically effective dose, is the same. Not doing so may result in incorrect inferences being made about the risks associated with that exposure. Three critical questions arise specifically, do men and women differ in (1) their personal environments (immediate physical environments and personal attributes), (2) their absorption of the substance across the various biological barriers, and (3) the amount of active substance that reaches the target sites? Both contextual (e.g., smoking habits, diet, use of personal care products and jewellery, hobbies, stress, and use of medications) and biological (e.g., endocrine status) factors should be considered in answering these questions. Examples from the literature are provided to show that, depending on the chemical compound, there may be sex and gender differences in exposure to chemicals which can be manifested in sex differences in absorption, distribution, metabolism, storage, and excretion. An argument is developed to support the need to make information available, such as pharmacokinetic modeling studies in both men and women including appropriate age groups representing the spectrum of life stages and reproductive status.