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.imagesp690-a