HISTORICAL-PERSPECTIVE ON PCBS

Polychlorinated biphenyls (PCBs) first became recognized as an environ mental issue in approximately 1970, Before that, analytical limitation s precluded their accurate and convenient detection in environmental s amples. Over the next several years, gas chromatography advances, exte nsive environmental sampling throughout the world, and numerous regula tory agency activities led to a better and broader understanding of PC Bs as an environmental issue. By the late 1970s, this learning phase c ulminated with tight regulatory controls being established on PCB use and disposal. To this day, however, PCB toxicity and the effects of en vironmental concentrations on human health are not well understood and regulatory control continues to evolve.