Comparison of CALUX-TEQ values with PCB and PCDD/F measurements in human serum of the Flanders Environmental and Health Study (FLEHS).

In 1999, a campaign of the Flemish Ministry of Health, Belgium was set up to assess pollutant concentrations and related health effect biomarkers in humans living in two regions of Flanders. The study was called the 'Flemish Environment and Health Study' (FLEHS). Concentrations of selected organochiorine pesticides, polychlorinated biphenyls (PCB) and polychlorinated dibenzo-p-dioxins (PCDD) and flirans (PCDF) were measured by gas chromatography-mass spectrometry in 47 pooled human serum samples originating from 200 individual women between 50 and 65 years living in two Flemish regions. The CALUX (Chemical-Activated Luciferase gene eXpression) bioassay was assessed on the same pools. The correlation between CALUX-TEQ and total TEQ (sum of PCDD/PCDF, non- and mono-ortho PCBs) varied from 0.43 to 0.73 for the rural and urban region, respectively. The mean value for the total TBQ (75 pg WHO-TEQ/g fat) was two times higher than the mean TEQ value determined with the CALUX bioassay (36 pg TEQ/g fat). This shows that the assessment of dioxin-like exposure by these two measurements was different. However, regional differences in concentrations were observed for neither total TEQs, nor CALUX-TEQs. It was concluded that the CALUX can be an alternative screening tool for biomonitoring purposes, especially when the objective is to compare different groups of people (e.g. living in different regions).

Speciation of ionic alkyllead in potable water and soil.

Various potable water and soil samples have been analyzed for tri- and dialkyllead compounds using a sensitive speciation procedure based on diethyldithiocarbamate extraction, Grignard derivatization and gas chromatography-atomic absorption spectrometry. The species are generally present as ultra-trace contaminants, and their abundance is critically discussed. In addition, a degradation study of ionic alkyllead in ambient matrices is presented.

Persistent organochlorine pollutants in human serum of 50-65 years old women in the Flanders Environmental and Health Study (FLEHS). Part 1: Concentrations and regional differences.

In 1999, a campaign of the Flemish Ministry of Health, Belgium was set up to assess pollutant concentrations and related health effect biomarkers in humans living in two regions of Flanders. The study was called the 'Flemish Environment and Health Study' (FLEHS). One of the goals was to measure present concentrations of persistent organochlorine pollutants in a Flemish population and to compare values obtained from pooled and individual serum samples. Concentrations of selected organochlorine pesticides, polychlorinated biphenyls (PCB) and polychlorinated dibenzo-p-dioxins (PCDD) and furans (PCDF) were measured by gas chromatography-mass spectrometry. TEQ values were also assessed by Chemical-Activated LUciferase gene eXpression (CALUX) bioassay. The study population consisted of 200 women between 50 and 65 years living in two areas of Flanders, Belgium. Because of the large volumes serum needed for all measurements, the concentrations of organochlorines were measured in 47 pooled serum samples originating from these women. The concentrations of the indicator PCBs (359.8 ng/g fat) and organochlorine pesticides (hexachlorobenzene, p,p'-dichlorodiphenyldichloroethylene, p,p'-dichlorodiphenyl-trichloroethane, lindane and pentachlorophenol), were comparable to those found in other European countries. The concentrations of PCDD/PCDFs showed another picture. With a median value of 48 pg WHO-TEQ/g fat, the women had 2-fold higher levels than a comparable age group from Germany examined in 1996. The mean total WHO-TEQ including PCDD/F, non-ortho and mono-ortho PCBs was 72.7 pg WHO-TEQ/g fat, whereas the CALUX-TEQ mean value was only 35.0 pg TEQ/g fat. In order to assess the pooling procedure, indicator PCBs and CALUX-TEQs were measured in all 200 individuals that were integrated in the pools. The measured values were comparable to the pool results: 390.0 ng/g fat and 41.6 pg TEQ/g fat respectively. It was concluded that pooling of serum samples offers the possibility to measure exposure in the whole study population on a more cost-effective way. However, because of statistical power loss and no possibility of confounder adjustment, pooling is not the most effective way to study regional differences.

Health risk assessment of dioxin emissions from municipal waste incinerators: the Neerlandquarter (Wilrijk, Belgium).

Two municipal waste incinerators in the vicinity of a residential area close to the city of Antwerp caused concern to local habitants. Risk assessment was performed combining chemical, toxicological measurements and model calculations. As the first step in risk assessment an inventory was made of historic emissions from both incinerators with emphasis on dioxins. The operational atmospheric transport and deposition model for priority substances (OPS) was used to calculate the deposition of dioxins in the vicinity of incinerators. The observed soil contamination pattern did not correspond to the calculated deposition pattern, indicating that other sources may contribute at least partly to the local PCDD/PCDF contamination of the area. Dioxin exposure of people in the Neerlandquarter as a function of the food consumption behavior was calculated using a mathematical model (VLIER-HUMAAN) combined with transfer factors. According to the results of these calculations, just residing in the impact area does not result in a meaningful risk. Only if locally produced food was consumed (milk, meat and vegetables), exposure in the Neerlandquarter was enhanced compared to the average dioxin exposure estimated for the Flemish population. Exposure in 1997 was below the exposure in 1980. As a consequence of different eating habits and lower bodyweight, children are subjected to significantly higher exposure than adults. Adverse health outcomes from dioxin exposure in the past cannot be excluded. There was no evidence for enhanced exposure to genotoxicants based on a comparison of chromosomal damage to blood cells of children from the study area to those from a control group.