Gender-related decrease in Raven's progressive matrices scores in children prenatally exposed to polychlorinated biphenyls and related contaminants

Abstract

Polychlorinated biphenyls (PCBs) and industrial mixtures that have been widely used throughout the world. PCBs have long environmental half lives and bioconcentrate, therefore contaminating soil, water, wild life, and human tissues. Typical human exposures come from environmental contamination of food supply, especially fresh water fish and meat, and occupational exposures. In certain uses, PCBs can partially oxidize and themselves become contaminated by extremely toxic compounds such as polychlorinated dibenzofurans (PCDFs). Two episodes of intoxication with heat-degraded PCBs have occurred, in Japan and Taiwan respectively. In 1979, over 2000 persons in Taiwan were intoxicated by heat-degraded PCBs that had contaminated their cooking oil. Kaneclor 500 (a Japanese PCB mixture) contained in the heating pipe was used as the heat transmitter. Leakage of the pipe introduced PCBs and heat-degraded products such as polychlorinated dibenzofurans (PCDFs) and polychlorinated quaterphenyls (PCQs) into the rice oil. Exposed victims developed chloracne, hyperpigmentation, peripheral neuropathy, and other signs and symptoms which were later called Yu-Cheng ({open_quotes}oil disease{close_quotes}) in Taiwan. These symptoms were caused not only by PCBs but by their heat degraded products, PCDFs. PCBs, PCDFs and PCDDs also can cross the placenta to affect the fetus and cause significant neurodevelopmental toxicity. Raven`s Colored Progressive Matrices (CPM)more » and Standarized Progressive Matrices (SPM) test spatial rather than verbal capabilities in children. These test are useful for determining whether prenatal exposure to PCBs/PCDFs cause differential effects on boys and girls. This paper reports results of CPM and SPM from age six to nine year in Yu-Cheng children and their matched controls. Cognative deficits up to 9 years of age were detected n children with prenatal exposure to PCBs and PCDFs, and boys were more affected than girls. 26 refs., 1 fig., 2 tabs.« less