Dioxin in infants--an environmental hazard?

The concentrations of the most common dioxin and dibenzofuran congeners were measured in different tissues (e.g. liver, kidneys, subcutaneous fatty tissue and spleen) from 27 infants who died suddenly and unexpectedly. The cases could be subdivided into 2 groups consisting of 15 infants who died in 1991/1992 and in 12 infants who died in 1996/1997. The autopsies were carried out using a standardised protocol and additionally the parents were asked to supply details of the nutritional conditions. The age of the mother and the birth order of the infants were also recorded. From the results obtained by correlating these parameters with the dioxin concentrations three main factors could be established: 1) there was a significant decrease in the total dioxin concentration in infant tissues from 1991/1992 to 1996/1997 indicating a decrease in the environmental dioxin levels due to a decrease in dioxin emission, 2) the birth order was inversely and the duration of breast feeding directly proportional to the dioxin concentrations thus showing that the mothers can decontaminate themselves by breast feeding and 3) an accumulation of specific dioxin congeners was observed in the liver tissue but the pathophysiological significance of these observations is not yet fully understood. Because of the well-known beneficial effects of breast feeding and considering the results of the present study, this type of infant nutrition can be recommended without any restrictions.

Human milk as a bioindicator for body burden of PCDDs, PCDFs, organochlorine pesticides, and PCBs.

In the State Laboratory of North Rhine-Westphalia for Food, Pharmaceutical and Environmental Chemistry (Chemisches Landesuntersuchungsamt), more than 600 individual human milk samples have been analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), and more than 1400 individual milk samples have been analyzed for organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) since 1984. All samples were collected on a voluntary basis from nursing mothers mostly living in North Rhine Westphalia, a federal state in Germany. The samples analyzed so far show a typical pattern of PCDDs and PCDFs. Out of the 210 possible congeners, only those with 2,3,7,8-chlorine substitution were found. While OCDD normally shows the highest concentration, the levels of the other dioxin congeners decrease with decreasing number of chlorine atoms. A different pattern was found for PCDFs. Within this group 2,3,4,7,8-P5CDF is the most abundant congener, followed by the hexachlorodibenzofurans. The mean level of tetrachlorodibenzodioxin (TCDD) was found to be of 3.2 pg/g on a fat basis and for total PCDDs and PCDFs, calculated as I-TEq (NATO/CMMS), 29.3 pg/g on a fat basis. The investigations of the past 2 years have revealed somewhat lower levels compared to former years. This might be an indication that the efforts undertaken to minimize dioxin emissions and to shut down known sources have already had an effect on the body burden of humans. Although mostly banned for a considerable period of time now, some lipophilic persistent pesticides such as DDT, dieldrin, hexachlorobenzene (HCB), and hexachlorocyclohexanes (HCH) can still be found in human milk.(ABSTRACT TRUNCATED AT 250 WORDS)