Protracted neurotoxicity from chlordane sprayed to kill termites.

Over 250 adults and children were exposed to chlordane when the wooden building surfaces and soil around an apartment complex were sprayed in 1987. Two hundred-sixteen adults had neurobehavioral functions measured and completed questionnaires for symptom frequency, mood status, confounding factors, and medical, rheumatic, and respiratory disorders in 1994. Measurements included simple and choice reaction time, balance, blink reflex latency, color vision, cognitive, perceptual motor, memory, and recall functions. We analyzed 216 exposed and 174 referent adults. Age, educational level, weight, height, and gender ratio were similar for the exposed and referent groups. Performance of balance, reaction times, Culture Fair, digit symbol, verbal recall, and trail-making were significantly impaired in exposed persons compared to referents. Mood-state scores were elevated, as were the frequencies of respiratory, neurobehavioral, and rheumatic symptoms. In contrast, long-term memory function was similar in both groups, consistent with its status before exposure. There was no identified bias or confounding factors. Chlordane exposure was associated with protracted impairment of neurophysiological and psychological functions. The central nervous system is the most important target of chlorinated cyclodiene insecticides. Human exposure should be prohibited.