A Review of Human and Sub-Human Primate Toxicity of Hexachlorobenzene

Abstract

The inadvertent exposure of a large cohort of individuals to hexachlorobenzene (HCB) in the mid-1950s in southeastern Turkey remains an environmental disaster that continues to fascinate and provide interesting observations concerning this ubiquitous chemical. A brief history of the exposure is presented with particular reference to the initial presentation of Pembe Yara and Porphyria Cutanea Tarda and later to reproductive performance in humans and sub-human primates. Differential toxicity is present in the oocytes of monkeys, with more severe damage identified in primordial germ cells rather than in growing oocytes. However, this observation did not express itself in women, as there was no increased incidence of premature menopause among those exposed. Germ cell toxicity remains a possible outcome of exposure, however. The serum HCB levels measured in exposed individuals predicted the lifetime risk of spontaneous abortion, not only in exposed individuals but also in the control populations, indicating that a possible population effect is present.