Summary and evaluation, conclusions and recommendations in French and Spanish.

Spanish 1st ed. issued as: Publicaci'on cient'ifica / Organizaci'on Panamericana de la Salud ; no. 387.

Evaluates the vast body of evidence demonstrating the serious threat to human and environmental health posed by polychlorinated biphenyls (PCBs). These chemicals, which are now ubiquitous in the environment, have been used commercially since 1930 as dielectric and heat-exchange fluids and in a variety of other applications. Over 1,300 studies were critically assessed. The book also contains a brief review of the limited data on polychlorinated terphenyls. A section devoted to the environmental behaviour of PCBs assesses the mechanisms by which these highly persistent chemicals, previously introduced into the environment, are gradually being redistributed towards increased contamination of the marine environment. For the general population, the most important sources of exposure are identified as food items and, for babies, breast-milk. The well-documented signs of poisoning in occupationally-exposed workers are also reviewed. A section devoted to the metabolic fate of PCBs cites evidence of accumulation in the liver and the adipose tissues of various organs, placental transport, fetal accumulation, and distribution to milk. The most extensive section, which runs some 100 pages, evaluates findings from studies of toxicity in experimental animals and in vitro systems. Findings suggest that PCBs are immunosuppressive and act as tumour promoters. An assessment of effects on humans draws upon studies of two large outbreaks of poisoning from contaminated food, and of occupational exposures. Concerning risks to the environment, the report cites reproductive failure in sea mammals as the most important hazard, further concluding that the predicted redistribution of residues towards the marine environment will pose an increasing hazard for sea mammals in the future. A review of the hazards of polychlorinated terphenyls concludes the report.

eng fre(1ed) spa(1ed).

jpn pol(1ed).

WHODOC

WHO monograph

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