Environmental contaminants and their significance for breastfeeding in the Central Asian Republics

Possible sources of contamination are agricultural pesticides, industrial chemicals, and radioactive materials. A review of research that has been published in English and a limited review of research that has been published in Russian regarding breast milk contamination reveals a weakness in existing data. Published reports are not based on scientific analyses of breast milk samples, and they often fail to specify the contaminant or provide details on the site from which samples were gathered. Further, no information is available on infant outcomes from breast milk contaminants in the Central Asian Republics. Previously unpublished data gathered from three Central Asian Republics during 1988-89 provide useful information on substances found in breast milk, including the range of concentration and the number of positive samples. In spite of the fact that DDT was restricted in the former USSR, the presence of the pesticide and its metabolites suggests its continued use. The amount of toxicants found in breast milk in the Central Asian Republics is similar to amounts reported in breast milk from other areas of the world. While most observers are aware of the potential risk of contamination through breast milk, there is less recognition of the importance of in utero exposure and direct exposure on infant outcomes. In addition, for young children who are not breastfeeding, breast milk substitutes, water, and food can be sources of contamination. Drinking water is the major source of nitrate exposure for children. For many substances, limiting breastfeeding is likely to have a small impact on the child"s total body burden. For very stable, non-metabolized, fat-soluble materials like PCBs and DDT or its metabolites, breastfeeding may contribute disproportionately to the infant"s exposure. However, studies conducted elsewhere report that chronic, low-level maternal exposures to environmental toxicants such as lead, nitrate, DDT, and PCBs have not resulted in measurable health effects in children who were exposed through breastfeeding. There are several isolated cases in the world where high body burdens of chemicals have been found in infants; these were generally the result of maternal poisoning that occurred through acute exposure in the work place or accidental food contamination during processing activities. A greater concern than acute intoxicants, some believe, is the long-term carcinogenic effect of exposure to breast milk contaminants. Researchers, using a model to estimate the potential cancer deaths from environmental chemicals in breast milk, concluded that the lifetime risk of cancer mortality is significantly less than the loss of life due to deaths associated with bottle feeding. While questions remain regarding the subtle and long-term impact of environmental contaminants on health outcomes, there is clear and documented evidence of the nutritional, immunological, contraceptive, and cost benefits from breastfeeding. A decline in breastfeeding rates in the Central Asian Republics would likely result in higher infant mortality and morbidity rates, and higher maternal fertility rates. Based on current knowledge of risks and benefits, breastfeeding should be supported and encouraged by policy makers and health professionals in the Central Asian Republics. Health professionals and the rehabilitation efforts should aim to reduce contaminants and the risk of exposure to infants and all members of society. (Author abstract)