95th Percentile Concentrations Research Articles

Estimation of Urinary Concentration of Aflatoxin M1 in Chinese Pregnant Women

Aflatoxin M1 (AFM1 ) is a main cause of hepatocarcenogenoma in Chinese population. Measurement of aflatoxin exposure in human may help in providing clear evidence for the exposure of specific environmental pollutants in certain population. "One child policy" in China offered parents more careful to choose safe food during pregnancy, but no reports published on the efficacy of their endeavor. In present study, we aimed to assess the exposure of AFM1 in Chinese pregnant women. The urine samples were collected from 600 volunteers from Zhejiang province, China and the urinary concentration of AFM1 was measured using ELISA kit. AFM1 was detected in 84% of the pregnant women. The geometric mean and 95th percentile concentration of AFM1 in pregnant women were 50.3 ng/L and 633.5 ng/L, respectively. Our results point out that pregnant women especially are at the high risk of exposure to AFM1 . Our results also indicate that although "one child policy" offered parents to pay more attention for the selection of safe food, but detection of AFM1 in urine of pregnant women indicate that more foods containing AFM1 still need to be detected. Highest exposure of AFM1 in pregnant women indicates that awareness campaigns must be started especially in the rural areas of China regarding the possible hazardous effects of AFM1 exposure in pregnant women.

Entering markets and bodies: Increasing levels of the novel plasticizer Hexamoll® DINCH® in 24h urine samples from the German Environmental Specimen Bank

DINCH (diisononylcyclohexane-1,2-dicarboxylate) was introduced into the world market in 2002 as a non-aromatic plasticizer and phthalate substitute. We analyzed 300 urine samples (24 h voids) of the German Environmental Specimen Bank (ESB for Human tissues, ESB Hum) for specific DINCH metabolites by on-line HPLC-MS/MS with isotope dilution quantification. Urine samples of the ESB Hum were from the years 1999, 2003, 2006, 2009 and 2012, chosen to investigate the appearance and a possible trend of DINCH exposure since its market introduction. No DINCH metabolites were detected in the 1999 and 2003 samples. From 2006 on, the percentage of samples with DINCH metabolites above the LOQ increased significantly over the years (7% in 2006, 43% in 2009 and 98% in 2012). The cyclohexane-1,2-dicarboxylic acid-mono(hydroxy-isononyl) ester (OH-MINCH) was the predominant metabolite. Median (and 95th percentile) concentrations (in μg/l) increased from <LOQ (0.09) in 2006, to <LOQ (1.02) in 2009 to 0.39 (2.09) in 2012. All oxidized DINCH metabolites (OH-MINCH, cx-MINCH, oxo-MINCH) correlated strongly among each other (ρ>0.75, p<0.001). The median (95th percentile) DINCH intake in 2012 was calculated to be 0.14 (1.07)μg/kg body weight/day which is considerably below daily intakes currently deemed tolerable. DINCH is regarded to have a preferred toxicological profile over certain anti-androgenic phthalates. The continuation of DINCH measurements in the ESB Hum and other human biomonitoring studies like the German Environmental Survey (GerES) allows tracking the development of DINCH body burdens, the distribution of exposure levels and daily intakes, providing basic data for future toxicological assessment and further epidemiological studies.

Organochlorine compounds, nitro musks and perfluorinated substances in breast milk – Results from Bavarian Monitoring of Breast Milk 2007/8

The aim of the Bavarian Monitoring of Breast Milk (BAMBI) project was to examine 10 organochlorine pesticides (OPs), 3 nitro musks, 6 indicator polychlorinated biphenyls (PCBs), 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like PCBs (dl-PCBs) and several perfluorinated alkyl compounds in breast milk samples. A total of 516 breast milk samples were collected from seven regions in Bavaria and were analyzed by means of GC/ECD, GC/HRMS, and LC/MS-MS.Concerning the OPs, only hexachlorobenzene and a metabolite of DDT, 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (p,p′-DDE), could be quantified in all samples (median: 16ngg−1 lipid and 63ngg−1 lipid, respectively). Median concentrations of 150ngg−1 lipid (range: 3–1900ngg−1 lipid) were found for the sum of the indicator PCBs. The concentrations of the PCDDs/PCDFs and the dl-PCBs ranged from 0.8 to 15.1 (median 5.7) pg WHO-TEQ1998g−1 lipid and from 1.5 to 18.9pg (median 6.4) WHO-TEQ1998g−1 lipid, respectively. The median perfluorooctane sulfonate concentration was 0.05μgL−1 (range: <0.02–0.26μgL), while the other PFCs were observed only in a subset of samples.On the basis of the median and 95th percentile concentration, “medium” and “high” intake levels were estimated for a 3-month-old exclusively breastfed infant. In particular, “medium” and “high” intake levels were calculated of 69 and 133pg WHO1998 TEQkg−1 b.w. for PCDDs/PCDFs, 8 and 21ngkg−1 b.w. for dl-PCBs, and 6 and 25ngkg−1 b.w. for perfluorooctane sulfonate, respectively.The calculated intake for perfluorinated substances is clearly below the tolerable daily intake (TDI), while the established TDI values are still clearly exceeded for PCDDs/PCDFs and dl-PCBs.

Levels and profiles of organochlorines and flame retardants in car and house dust from Kuwait and Pakistan: Implication for human exposure via dust ingestion

There are only few studies documenting indoor pollution in the Middle East and the Indian subcontinent. In present study, we have evaluated the occurrence of various organochlorines (OCs) and flame retardants (FRs) in dust from cars and houses of Pakistan and Kuwait. Polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), organophosphate FRs (PFRs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were investigated in indoor dust from urban houses (N=15 per country) and cars (N=15 per country). PFRs were the major analytes in all four microenvironments, followed by PBDEs>NBFRs>OCPs>PCBs. For all classes of analytes, relatively lower levels were observed in car and house dust from Pakistan than Kuwait. Levels of ∑PBDEs, ∑NBFRs and ∑PFRs were higher in car dust, while ∑OCPs and ∑PCBs were higher in house dust from both countries. ∑PFRs occurred at average concentrations of 16,900, 87,900, 475, and 2500ng/g in Kuwaiti house and car, and Pakistani house and car dust, respectively. For both countries, the profiles of analytes in car dust were different from those in the house dust. Different exposure scenarios using 5th percentile, median, mean, and 95th percentile levels were estimated for adult, taxi drivers and toddlers. For Kuwaiti toddlers, assuming high dust intake and mean and 95th percentile concentrations, the values computed for ∑OCPs (1500ng/kg bw/day) were higher than RfD values, while for ∑PCBs (14.5ng/kg bw/day) it was only two-fold lower than the corresponding RfDs.

The Southeastern Aerosol Research and Characterization (SEARCH) study: Spatial variations and chemical climatology, 1999–2010

The Southeastern Aerosol Research and Characterization (SEARCH) study, which has been in continuous operation from 1999 to 2012, was implemented to investigate regional and urban air pollution in the southeastern United States. With complementary data from other networks, the SEARCH measurements provide key knowledge about long-term urban/nonurban pollution contrasts and regional climatology affecting inland locations and sites along the Gulf of Mexico coastline. Analytical approaches ranging from comparisons of mean concentrations to the application of air mass trajectories and principal component analysis provide insight into local and area-wide pollution. Gases (carbon monoxide, sulfur dioxide, nitrogen oxides, ozone, and ammonia), fine particle mass concentration, and fine particle species concentrations (including sulfate, elementary carbon, and organic carbon) are affected by a combination of regional conditions and local emission sources. Urban concentrations in excess of regional baselines and intraurban variations of concentrations depend on source proximity, topography, and local meteorological processes. Regional-scale pollution events (95th percentile concentrations) involving more than 6 of the 8 SEARCH sites are rare (< 2% of days), while subregional events affecting 4–6 sites occur on ˜10% of days. Regional and subregional events are characterized by widely coincident elevated concentrations of ozone, sulfate, and particulate organic carbon, driven by persistent synoptic-scale air mass stagnation and higher temperatures that favor formation of secondary species, mainly in the summer months. The meteorological conditions associated with regional stagnation do not favor long-range transport of polluted air masses during episodes. Regional and subregional pollution events frequently terminate with southward and eastward penetration of frontal systems, which may initially reduce air pollutant concentrations more inland than along the Gulf Coast. Implications: Regional distribution of emission sources and synoptic-scale meteorological influences favoring stagnation lead to high regionwide pollution levels. The regional influence is greatest with secondary species, including ozone (O3) particulate sulfate (SO4), and particulate organic matter, some of which is produced by atmospheric oxidation of volatile organic compounds (VOCs) from vegetation and anthropogenic sources. Other species, many of which are from primary emissions, are more influenced by local sources, especially within the Atlanta, GA, and Birmingham, AL, metropolitan areas. Limited measurements of modern and fossil total carbon point to the importance of biological and biogenic emissions in the Southeast.

Particulate pollution from brick kiln clusters in the Greater Dhaka region, Bangladesh

Brick manufacturing is the fastest-growing industrial sector in Bangladesh and among the top three sectors, along with vehicle exhaust and resuspended road dust, contributing to the air pollution and health problems in Dhaka. The brick manufacturing in the Greater Dhaka region, from ~1,000 brick kilns spread across six districts, is confined to the winter season (October to March) as current technologies do not allow production during the monsoon. The total emissions are estimated at 23,300 t of PM2.5, 15,500 t of sulfur dioxide (SO2), 302,000 t of carbon monoxide (CO), 6,000 t of black carbon, and 1.8 million tons of CO2 emissions from these clusters, to produce 3.5 billion bricks per year, using energy-inefficient fixed chimney bull trench kiln technology and predominantly using coal and agricultural waste as fuel. The associated health impacts largely fall on the densely populated districts of Dhaka Metropolitan Area (DMA), Gazipur, and Narayanganj. Using the Atmospheric Transport Modeling System dispersion model, the impact of brick kiln emissions was estimated over DMA—ranging from 7 to 99 μg/m3 (5th and 95th percentile concentration per model grid) at an average of 38 μg/m3; and spatial contributions from the surrounding clusters—with 27 % originating from Narayanganj (to the south with the highest kiln density), 30 % from Gazipur (to the north with equally large cluster spread along the river and canals), and 23 % from Savar. The modeling results are validated using evidence from receptor modeling studies conducted in DMA. An introduction of emerging vertical shaft combustion technology can provide faster benefits for public health in DMA and reduce climate precursor emissions by selecting the most influential clusters discussed in this paper.

Relevance of drinking water as a source of human exposure to bisphenol A

A comprehensive search of studies describing bisphenol A (BPA) concentrations in drinking water and source waters (i.e., surface water and groundwater) was conducted to evaluate the relevance of drinking water as a source of human exposure and risk. Data from 65 papers were evaluated from North America (31), Europe (17), and Asia (17). The fraction of drinking water measurements reported as less than the detection limit is high; 95%, 48%, and 41%, for North America, Europe, and Asia, respectively. The maximum quantified (in excess of the detection limit) BPA concentrations from North America, Europe, and Asia are 0.099 μg/l, 0.014 μg/l, and 0.317 μg/l. The highest quantified median and 95th percentile concentrations of BPA in Asian drinking water are 0.026 μg/l and 0.19 μg/l, while high detection limits restricted the determination of representative median and 95th percentile concentrations in North America and Europe. BPA in drinking water represents a minor component of overall human exposure, and compared with the lowest available oral toxicity benchmark of 16 μg/kg-bw/day (includes an uncertainty factor of 300) gives margins of safety >1100. Human biomonitoring data indicate that ingestion of drinking water represents <2.8% of the total intake of BPA.

Have Regulatory Efforts to Reduce Organophosphorus Insecticide Exposures Been Effective?

Background: The Food Quality Protection Act (FQPA) was signed into law in 1996 to strengthen the regulation of pesticide tolerances in food. Organophosphorus (OP) insecticides were the first group of pesticides reviewed by the U.S. Environmental Protection Agency (EPA) under the new law.Objective: Our goal was to determine whether urinary concentrations of dialkylphosphate (DAP) metabolites of OP pesticides declined between the National Health and Nutrition Examination Survey (NHANES) III and NHANES 1999–2004.Methods: Using mass spectrometry–based methods, we analyzed urine samples from a nationally representative sample of 2,874 adults 20–59 years of age in NHANES 1999–2004 and samples from a non-nationally representative sample of 197 adult participants for NHANES III (1988–1994) for six common DAP metabolites of OP pesticides.Results: Median urinary DAP concentrations decreased by more than half between NHANES III and NHANES 2003–2004. Reductions of about 50%–90% were also observed for 95th percentile concentrations of five of the six metabolites. Frequencies of detection (FODs) decreased in all six metabolites (< 50% reduction). On average, median and 95th percentile concentrations and FODs showed a larger decrease in diethylphosphate metabolites than dimethylphosphate metabolites.Conclusions: Human exposure to OP insecticides as assessed by urinary DAP concentrations has decreased since the implementation of the FQPA, although we cannot be certain that U.S. EPA actions in response to the FQPA directly caused the decrease in DAP concentrations.

Prediction of environmental concentrations of glucocorticoids: The River Thames, UK, as an example

Synthetic glucocorticoids (GCs) are consumed in large amounts as anti-inflammatory and immunosuppressive drugs worldwide. Based on what has been learnt from studies of other human pharmaceuticals, they are likely to be present in the aquatic environment. However, to date, information on the environmental concentrations of GCs is very limited. The situation is complicated by the fact that a considerable number of GCs are in everyday use in most developed countries. Hence, obtaining a full picture of GC concentrations in the aquatic environment using the traditional analytical chemistry approach would be time-consuming and expensive. Thus, we took a modelling approach to predict the total environmental concentration of all synthetic GCs (consisting of 28 individual GCs) in the River Thames, as a first step in risk assessment of these drugs. Using reliable data on consumption, the LF2000-WQX model predicts mean concentrations up to 30ng/L of total GCs in surface water as a best case scenario when the lowest excretion and highest removal rates in sewage treatment works were used, whereas mean concentrations up to 850ng/L were predicted when the highest excretion and lowest removal rates are considered. We also present the 10th and 90th percentile concentrations (which indicate the likely range of concentrations seen from high flow to low flow conditions in the river) of the highest and lowest consumed GCs, to show the spatial and temporal variations of the concentrations of individual GCs. These data probably provide reliable estimates of the likely range of concentrations of GCs in a typical river impacted by effluent from many sewage treatment plants. Results also identify the hot spots where field studies on fish could be focused. To determine if aquatic organisms face any threat from GCs, laboratory toxicity studies should be conducted using concentrations similar to those reported here.

Analysis of perfluoroalkyl carboxylates in vacuum cleaner dust samples in Japan

Perfluorooctanoic acid (PFOA) has long been an environmental contaminant of concern owing to its potential health risk. However, exposure to perfluorinated carboxylic acids (PFCAs) other than PFOA is not well understood. In this study, we investigated the concentrations of PFCAs in vacuum cleaner dust in Japan to measure the PFCAs contamination in an indoor environment. Most of the 77 samples contained PFCAs with 6–13 carbon atoms. The median concentration of perfluorononanoic acid (PFNA, 23.2 ng g −1) was highest among PFCAs, followed by PFOA (20.8 ng g −1) and perfluoroundecanoic acid (PFUnDA, 12.9 ng g −1). The 90th percentile concentrations of PFNA, PFUnDA and perfluorotridecanoic acid (PFTrDA) were 948, 283 and 110 ng g −1, respectively, and these were detected at greater concentrations than neighboring, even-numbered PFCAs. The proportion of long-chain PFCAs in vacuum cleaner dust from Japan was relatively higher than those reported for other countries. Factor analysis showed three independent factors. Odd-numbered long chain PFCAs (PFNA, PFUnDA and PFTrDA), which can correspond to factor 1, were major components of PFCAs in vacuum cleaner dust. Short chain PFCAs (factor 2) and even numbered long chain PFCAs (factor 3) were also statistically separated. These findings suggest that there are several sources of PFCAs with different origins in indoor environment. Further investigations into the origins of PFCAs are needed to evaluate indoor contamination with PFCAs.

Urinary Concentrations of Dialkylphosphate Metabolites of Organophosphorus Pesticides: National Health and Nutrition Examination Survey 1999–2004

Organophosphorus (OP) insecticides were among the first pesticides that EPA reevaluated as part of the Food Quality Protection Act of 1996. Our goal was to assess exposure to OP insecticides in the U.S. general population over a six-year period. We analyzed 7,456 urine samples collected as part of three two-year cycles of the National Health and Nutrition Examination Survey (NHANES) from 1999–2004. We measured six dialkylphosphate metabolites of OP pesticides to assess OP pesticide exposure. In NHANES 2003–2004, dimethylthiophosphate was detected most frequently with median and 95th percentile concentrations of 2.03 and 35.3 μg/L, respectively. Adolescents were two to three times more likely to have diethylphosphate concentrations above the 95th percentile estimate of 15.5 μg/L than adults and senior adults. Conversely, for dimethyldithiophosphate, senior adults were 3.8 times and 1.8 times more likely to be above the 95th percentile than adults and adolescents, respectively, while adults were 2.1 times more likely to be above the 95th percentile than the adolescents. Our data indicate that the most vulnerable segments of our population—children and older adults—have higher exposures to OP pesticides than other population segments. However, according to DAP urinary metabolite data, exposures to OP pesticides have declined during the last six years at both the median and 95th percentile levels.

Risk characterization for mercury, dichlorodiphenyltrichloroethane and polychlorinated biphenyls associated with fish consumption in Serbia

The aim of this work was to assess the risk due to mercury (Hg), dichlorodiphenyltrichloroethane (DDT) and non-dioxin-like polychlorinated biphenyls (ndl PCBs) intake via fish consumption in Serbia. We have developed 24 scenarios using four concentration levels (mean, maximum, 50th and 95th percentile) of contaminants, determined in 521 samples of fish products available on Serbian market; two consumption levels (Food and Agriculture Organization/World Health Organization data and recommendation of American Heart Association); and three body weights (5th, 50th and 95th percentile). All the values concerning the intake of DDT are below the corresponding health based guidance value. Calculated weekly intake of Hg using maximal concentration, intake of 340g/week and 5th percentile of body weight exceeded the provisional tolerable weekly intake (PTWI). When maximal and 95th percentile concentration of ndl PCBs was used, weekly intakes exceeded a “guidance value” with one exception i.e., when 95th percentile of concentration along with 95th percentile of body weight were used. Concerning Hg and ndl PCBs, when extreme concentrations were used, HIs exceeded the value of 1, indicating that fish and fishery products may pose a threat to consumer’s health.

Daily intake and human risk assessment of organochlorine pesticides (OCPs) based on Cambodian market basket data

To assess organochlorine pesticide (OCP) contaminations and its possible adverse health impacts, different food samples were collected from three areas of Cambodia, one of the poorest countries in the world. The ∑OCP concentrations in Kampong Cham, Kratie and Kandal provinces ranged from 1.28 to 188 (median 3.11), 1.06 to 25.1 (5.59) and 2.20 to 103 (20.6) ng g −1, respectively. The dichlorodiphenyltrichloroethanes (DDTs) were the predominant OCPs and accounted for 62.2% (median) among all foodstuffs. Congener profile analyses suggested that there were new input sources of DDTs and hexachlorocyclohexanes (HCHs) in Cambodia, particularly in Kandal province. The estimated daily intake of OCPs (330 ng kg −1 day −1) for residents in Kandal province ranked No. 1 among the 13 compared countries or regions. On the basis of 95th percentile concentrations, the carcinogenic hazard ratios (HRs) of most investigated individual OCPs in vegetable and fish in Cambodia exceeding unity. Particularly for α-HCH in vegetable, the 95th HR was as high as 186. The data revealed that there is a great cancer risk for the local residents with life time consumption of OCP contaminated vegetable and fish. To our knowledge, this the first study to evaluate the daily intakes of OCPs in Cambodia.

Early life-stage and multigeneration toxicity study with bisphenol A and fathead minnows ( Pimephales promelas)

Regulatory guidelines for long term testing to assess the toxicity of xenobiotic compounds such as bisphenol A (BPA) with fish have focused on survival, growth, and development in early life stages. Early life stages are critical windows of exposure, but do not address later phases in the life cycle, such as reproduction, that are equally important for the continued survival of the organisms. Residual amounts of BPA are released to surface water. BPA has, therefore, been the subject of considerable toxicity testing with fish and other aquatic organisms. A long term multigeneration test with fish has been conducted to better interpret the environmental relevance of detectable levels of BPA. Fathead minnow ( Pimephales promelas) were exposed for 444 days over the course of three generations that included F0 reproducing adults, F1 eggs grown to be reproducing adults, and F2 eggs. Endpoints included survival, growth, reproduction, and vitellogenin concentrations. Concentrations tested ranged from 1 to 1280 μg/L. No observed effect concentrations (NOEC) of 640 μg/L and higher for growth parameters show few differences between age or generation. Reproductive NOEC in F0 and F1 breeding pairs were 640 and 160 μg/L, respectively. The lowest NOEC related to survival, growth and development or reproduction was 16 μg/L for F2 hatching success. This long term study covered both early life and adult reproduction stages that allowed examination of all critical windows of exposure. Overall, NOEC ranging from 16 to 1280 μg/L were found, which are well above median and upper 95th percentile concentrations of BPA in fresh waters in North America and Europe (0.081 and 0.47 μg/L and 0.01 and 0.035 μg/L, respectively). The likelihood is low that measured concentrations of BPA in surface water would affect fish, even if exposed over more than one generation.

Health Risk Assessment of Organochlorine Contaminants in Fish from a Major Lake (Baiyangdian Lake) in North China

Organochlorine contaminants (OCs) in fish were determined to evaluate the potential risk to humans consuming fish originating in Baiyangdian Lake, North China. Relatively low levels of PCBs, HCHs and DDTs were observed, with mean concentrations ranging from 0.28 to 3.28 ng/g, wet weight. Among various fish species tested, the highest burden of OCs was recorded in northern snakehead (7.39 ng/g, wet weight) and the lowest was in grass carp (2.04 ng/g, wet weight). The hazard ratios (HRs), based on noncancer risk were all less than 1.0, while the HRs based on cancer risk exceeded 1.0 only for PCBs based on the 90th percentile concentration.

“Novel” brominated flame retardants in Belgian and UK indoor dust: Implications for human exposure

Concentrations of several “novel” brominated flame retardants (NBFRs) are reported in indoor dust samples from Belgian houses ( n = 39) and offices ( n = 6) and from day-care centers and schools in the West Midlands of the UK ( n = 36). Using a GC-ECNI/MS method, the following NBFRs were quantified: decabromodiphenyl ethane (DBDPE) (range <20–2470 ng g −1), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) (range <0.5–1740 ng g −1), tetrabromobisphenol A-bis(2,3-dibromopropylether) (TBBPA-DBPE) (range <20–9960 ng g −1), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) (range <2–436 ng g −1) and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH) (range <2–6175 ng g −1). Hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), another NBFR, was below the detection limit of 2 ng g −1 dust in all dust samples. No correlation was detected between concentrations of NBFRs and PBDEs. The ratio of TBB:TBPH in the dust samples ranged from 0.01 to 4.77 (average 0.42), compared to the ratio present in the commercial flame retardant product FM 550 (TBB:TBPH = 4:1). Furthermore, no correlation was detected between concentrations in dust of TBB and TBPH. This may suggest different sources of these NBFRs, or similar sources but compound-specific differences in their indoor fate and transport. Exposure via dust ingestion was estimated for both adults and toddlers under low-end (5th percentile), typical (median), and high-end (95th percentile concentrations) scenarios. These were calculated assuming 100% absorption of intake dust and using mean dust ingestion (adults = 20 mg d −1; for toddlers = 50 mg d −1) and high dust ingestion (adults = 50 mg d −1; for toddlers = 200 mg d −1). Typical exposure with high dust ingestion estimates for adults were 0.01, 0.2, 0.01, 0.02 and 0.08 ng kg −1 bw d −1 and for toddlers 0.05, 1.9, 0.08, 0.4 and 1.12 ng kg −1 bw d −1 for BTBPE, DBDPE, TBB, TBPH and TBBPA-DBPE, respectively. Our results showed that, similar to PBDEs, toddlers have higher exposure to NBFRs than adults. This study documents the presence of NBFRs in indoor environments, and emphasizes the need to evaluate the health implications of exposure to such chemicals.

1062 The Selected Lipids Parameters in Newborns and Infants

Introduction: Disorders of lipids metabolism, particularly elevated cholesterol concentration are favouring factors of atherosclerotic changes in the arteries. The lipids metabolism may be the results of the influence of genetic as well as environmental factors. Aim: The aim of the present study was the evaluation of the concentration of triglycerides, total cholesterol and its fractions and apolipoproteins in the newborns and infants with relation to intrauterine growth, nutritional status and method of feeding from the birth. Material and Methods: The research included 185 newborns and infants aged 2 -19 weeks. In all the studied children the gestational age, birth weight, body mass index (BMI) and the method of feeding was assessed. In the blood serum the concentrations of triglicerides, total cholesterol and its fractions: LDL, VLDL and HDL as well as apo-AI and apo-B were determined. Results: Concentrations of triglycerides and VLDL cholesterol were significantly lower (p< 0.05) in children with birth weight below 10-th percentile in relation to the gestational age. In children with BMI values over 90-th percentile concentrations of triglicerydes, total cholesterol, VLDL cholesterol and apolipoprotein B were significantly higher (p< 0.05). The concentrations of the total cholesterol, VLDL cholesterol, apo- AI and apo-B were higher in breast-fed children when compared to the children fed with formula (p< 0.05). Conclusion: The obtained results can suggest that the concentrations of lipids, lipoproteins and apolipoproteins in infants may depend on theirs intrauterine development, nutritional status and the method of feeding from the birth.

Intake and body burden of dioxin-like compounds in Germany: The INES study

The human body burden of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) and the dietary intake of dl-PCB were investigated in Germany. In total, 50 adults (between 14 and 60 years old) were recruited, and duplicate diet samples were collected over seven consecutive days from each participant. Blood samples were acquired from 48 participants. Seventeen PCDD/Fs and 12 dl-PCBs (non- and mono-ortho congeners) were measured in the blood, and all dl-PCBs were measured in duplicate diet portions. Daily intake via food was calculated by multiplying the measured concentrations by the consumption data. Median (95th percentile) concentrations in the blood (expressed as WHO-TEQ) for PCDD/Fs, non-ortho PCBs and mono-ortho PCBs were 10.1 (25.0) pg g −1 lipid, 4.2 (14.9) pg g −1 lipid and 4.5 (14.2) pg g −1 lipid, respectively. The contribution of mono-ortho PCBs and non-ortho PCBs to total TEQ was 25% and 24%, respectively. For each study subject, median intake levels for seven consecutive days were calculated. From these data, the median (95th percentile) daily intake via food was 0.12 (0.32) pg TEQ kg −1 b.w. for non-ortho congeners and 0.06 (0.12) pg TEQ kg −1 b.w. for the mono-ortho congeners. PCB 126, PCB 118 and PCB 156 accounted for about 93% of the total PCB intake. Our study indicates that dl-PCB exposure in adults consuming a normal mixed diet is quite low at present in Germany. The median and maximum daily intake contributed to 10% and 25% to the tolerable daily intake recommended for total PCDD/Fs and dl-PCBs.

Exposure Analysis of Bisphenol A in Surface Water Systems in North America and Europe

This study was conducted to develop a statistical understanding of exposures to bisphenol A (BPA) in aquatic environments in North America and Europe. Concentrations of BPA have been reported by 89 investigations published between 1997 and 2007. On the basis of an analysis of weighted observations (n = 1068 and 848 for North America and Europe, respectively), BPA was reported at concentrations above the detection limit in 20-51% of freshwater samples. Median BPA concentrations for fresh surface waters for North America and Europe were 0.081 and 0.01 microg/L, respectively, while 95th percentiles were 0.47 and 0.35 microg/L, respectively. In contrast to fresh surface waters, only limited data are available for sediments and less for marine ecosystems. For freshwater sediments in North America (n = 71), the median and 90th percentile concentration (the 95th percentile was not calculable) were 0.6 and 3.4 ng/ g-dw, respectively, while the median and 95th percentile concentration in Europe (n = 249) were 16 and 256 ng/g-dw, respectively. To assess the potential ecological significance, we compared exposure concentrations with available regulatory criteria. The results suggest the frequency of locations in which concentrations are likely to cause adverse effects on aquatic ecosystems is low, with the exception of sediments collected from some highly urbanized and industrial locations.

Cholinesterase inhibition in chlorpyrifos workers: Characterization of biomarkers of exposure and response in relation to urinary TCPy

The objective of this study was to evaluate the quantitative relation between measured red blood cell acetylcholinesterase (RBC AChE) and plasma butyrylcholinesterase (BuChE) activities with exposure to chlorpyrifos (CPF) as assessed by measurement of urinary 3,5,6-trichloro-2-pyridinol (TCPy) in a study group of workers occupationally exposed in the manufacture of CPF and a referent group of chemical manufacturing workers. Measures of plasma BuChE and RBC AChE activity and urinary TCPy concentration collected over a year-long study (1999-2000) in CPF-exposed workers (n=53) and referents (n=60) were analyzed using linear mixed models to characterize exposure-response relationships. Intraindividual variability in cholinesterase measures was compared between CPF-exposed workers and referents. Urinary TCPy concentrations in CPF workers were substantially elevated compared to referents, with median and 95th percentile concentrations during typical employment conditions 10-fold and more than 30-fold higher, respectively, than corresponding measures in the referents. Intraindividual variability in cholinesterase activities was substantial, with 17% of unexposed referents experiencing one or more plasma BuChE measures more than 20% below baseline over a year of repeated, periodic measurements. RBC AChE activity, an early biomarker of effect, was unrelated to urinary TCPy concentration over the entire range of exposure, up to 1000 microg TCPy/g creatinine (Cr). Plasma BuChE activity, a non-adverse biomarker of exposure, was negatively related to urinary TCPy concentrations above approximately 110 microg TCPy/g Cr. No-effect levels for inhibition of plasma BuChE and RBC AChE corresponding to absorbed doses of CPF of approximately 5 and greater than 50 microg/kg/day, respectively, were identified. These findings are consistent with previous no-effect level determinations for ChE inhibition in humans and suggest that general population CPF exposure levels are substantially below the identified no-effect levels. The dose-response relationships observed in this study are consistent with predictions from the previously published physiologically based pharmacokinetic/pharmacodynamic model for CPF. Intraindividual variability in measured cholinesterase activities in referents was substantial, suggesting that ongoing monitoring programs may have a substantial rate of false positives.