Elemental mercury exposure among children of thermometer plant workers

Because evidence of mercury exposure was found among workers of a mercury thermometer-manufacturing plant in March 1984, the Vermont Department of Health studied the workers' children for both exposure to mercury and evidence of mercury toxicity. The median urine mercury level of 23 workers' children was 25 micrograms/L. This was significantly higher than the level (5 micrograms/L) among 39 children randomly selected from nonworkers' households in the same community (P less than .001). Mercury-in-air levels measured in workers' homes were higher than those measured in control homes. A significant correlation was found between the urine mercury levels of the workers' children and the urine mercury levels of their working parents. No child had frank mercury toxicity. No evidence of neurologic toxicity among exposed children was discovered by a pediatric neurologist who examined these and unexposed children without knowledge of their exposure status. This is the first report demonstrating mercury exposure in children of mercury workers. Although toxic effects of mercury were not demonstrated at these levels of exposure, children of mercury workers are at risk for mercury exposure and potential mercury toxicity.