Studies on organochlorine environmental contaminants with emphasis on analytical methods and occurrence in humans

Methods for multicomponent analysis of lipophilic organochlorine contaminants(OCs) in blood plasma and lipid-rich tissues are presented. By using the described methods, polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), hexachlorobenzene(HCB), 1,1-dichloro-2,2-bis(4 chlorophenyl)ethene (p,p'-DDE) and methylsulphonyl metabolites of PCB (MeSO2-PCB) and p,p'-DDE (Meso2-DDE) were determined in human blood plasma, adipose tissue and liver. In addition, polychlorinated dibenzo-p-dioxinsand dibenzofurans (PCDD/F) were determined in selected samples of blood plasma. The profiles and levels of PCB, PCN, HCB and p,p'-DDE were similar in adipose tissue and liver, while differences were found for MeSO2-PCB and MeSO2-DDE. The concentration(on lipid weight basis) of the metabolites was about 10 times higher in liver than in adipose tissue. Furthermore, meta-substituted isomers of MeSO2-PCB were selectively retained in the liver. The most abundant methylsulphonyl metabolite in the liver was 3-MeSO2-2,2',3',4',5,6-hexaCB, followed by 3-MeSO2-DDE. In adipose tissue, 3-MeSO2-DDEwas the most abundant metabolite. PCB, HCB, p,p'-DDE, MeSO2-PCB and MeSO2-DDE were determined in whole plasma and in the fractions obtained after separation of the plasma into very low density lipoprotein(VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL) and lipoprotein-depleted (LPDP) fractions. The OCs were present in all fractions, but predominantly in the LPDP fraction. A tendency to greater association of meta-substituted compounds of MeSO2-PCB to the LPDP fraction was noted. Among the lipoprotein fractions, LDL was the main carrier of PCB, HCB and p,p'-DDE. 3-MeSO2-DDE was predominantly found in the HDL fraction and MeSO2-PCB was distributed about equally between LDL and HDL fractions. A local source of contamination with PCB and PCN was traced to old electronic equipment, which was temporarily stored next to the laboratory. It was shown thatPCB and PCN may emit from electronics and pollute the indoor air. However, occupational exposure to PCB, PCN, PCDD/F and/or HCB could not be confirmed in a pilot study of plasma from persons who had worked with cable incineration or electronic equipment.