Health effects of long-term mercury exposure among chloralkali plant workers

Background Inorganic mercury is toxic to the nervous system, kidneys, and r eproductive system. We studied the health effects of mercury exposure among former employees of a chloralkali plans that operated from 1955 to 1994 in Georgia. Methods Former plant workers and unexposed workers from nearby employers we re studied. Exposure was assessed with a job-exposure matrix based on histo rical measurements and personnel records. Health outcomes were assessed wit h interviews physical examinations, neurological and neurobehavioral testin g, renal function testing, and urinary porphyrin measurements. Exposure-dis ease associations were assessed with multivariate modeling. Results Exposed workers reported more symptoms, and tended toward more phys ical examination abnormalities, than unexposed workers. Exposed workers per formed worse than unexposed subjects on some quantitative tests of vibratio n sense, motor speed and coordination, and tremor, and on one test of cogni tive function. Few findings remained significant when exposure was modeled as a continuous variable. Neither renal function nor porphyrin excretion wa s associated with mercury exposure. Conclusions Mercury-exposed chloralkali plant workers reported more symptom s than unexposed controls, but no strong associations were demonstrated wit h neurological or renal function or with porphyrin excretion. Am. J. Ind. M ed. 39:1-18, 2001. (C) 2001 Wiley-Liss, Inc.