Polychlorinated biphenyls in Spanish adults: determinants of serum concentrations.

BACKGROUND: Polychlorinated biphenyls (PCBs) are persistent compounds that may pose an environmental hazard to humans, food being the main source of exposure for the general population. OBJECTIVE: To measure the serum concentrations of the main PCBs in subjects from the general population in Spain, and to assess potential determinants of such concentrations. METHODS: Serum was obtained from blood samples of 953 subjects aged 35-64 years, residents in five Spanish regions (three from the North and two from the South), randomly selected from the EPIC-Spain cohort. Blood collection took place during 1992-1996 and four PCB congeners (118, 138, 153 and 180) were determined by means of gas chromatography with electron-capture detection (GC-ECD). RESULTS: The concentration of total PCBs was 459 ng/g lipids (or 3.1 microg/l); the corresponding figures for PCB 153 were 186 ng/g lipids and 1.25 microg/l. Men had higher values than women, PCB levels increased with age, and serum concentration of PCBs was higher in northern regions. Body mass index (BMI) was inversely related to PCB concentrations, and fish intake was the dietary factor showing the greatest association with serum PCBs. The pattern described was similar for each congener separately. CONCLUSIONS: We found concentrations similar to those reported in European countries where blood collection was carried during the same period. Regional differences within Spain are not fully explained by anthropometric or dietary factors. The inverse association with BMI suggests that in the mid-1990s there was still ongoing or recent exposure to PCBs in Spain.

Method for the determination of selected organochlorine pesticides and polychlorinated biphenyls in human serum based on a gel permeation chromatographic clean-up.

A gel permeation chromatographic (GPC) clean-up based method was developed for determination of selected organochlorine pesticides and polychlorinated biphenyls in human serum. The method permits automation of the sample extract clean-up stage and is designed to work with small amounts of sample. Different working variables were studied in its development, including injection volume, flow rate, and fat amount as the most representative coextract. The method provides solvent and time savings. Initial extraction was performed using 96-well solid-phase disk extraction plates, and quantification was performed by gas chromatography with electron capture detection and mass spectrometry. Recoveries of PCB congeners 28, 52, 101, 118, 138, 153, and 180 and organochlorine pesticides HCB, beta-HCH, gamma-HCH, heptachlor epoxide, p,p'-DDE, and p,p'-DDT at two spiking levels ranged from 55% to 115% with relative standard deviations ranging from 2.0% to 14.6%. Limits of quantification ranged from 0.06 to 0.16 ng mL(-1) for PCBs and from 0.12 to 0.36 ng mL(-1) for organochlorine pesticides. Finally, the method was applied to the analysis of 38 serum samples and the results were compared with those of another procedure validated at the laboratory.

Serum levels of organochlorine pesticides in healthy adults from five regions of Spain.

The aim of this study was to measure of serum levels of p,p'-dichlorodiphenyl trichloroethane (p,p'-DDT), p,p'-dichlorodiphenyl dichlorethylene (p,p'-DDE), beta-hexachlorocyclohexane (beta-HCH), and hexachlorobenzene (HCB) in healthy adults in Spain. Furthermore, we also analyzed these levels according to dietary, other lifestyle factors and anthropometric characteristics. We measured the concentrations of such organochlorine pesticides (OCPs) in serum samples collected during 1992-1996 from 953 subjects aged 35-64 years, they were residents of five Spanish regions, they were randomly selected from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. OCPs were determined by means of gas chromatography with electron-capture detection (GC-ECD). The most frequent compound found in serum was p,p'-DDE, present in 98% of the samples, followed by HCB and beta-HCH, found in 89% and 77% of samples, respectively, while p,p'-DDT could be measured only in 26% of subjects. The geometric means of serum concentrations (ng/g lipid) were 822 for p,p'-DDE, 167 for beta-HCH, and 379 for HCB. The concentrations of all OCPs were positively associated with age and body mass index, and decreased along the period of blood collection. No association was found between OCPs levels and dietary factors. The concentrations of p,p'-DDE and beta-HCB were higher in Murcia, one of southern regions, most likely associated with intensive past use of pesticides related to agricultural practices, while higher levels of HCB were found in Navarra, located in the north, maybe due to industrial use rather than agricultural application.