Low level and bystander exposure to lead among factory workers.

A clinical field survey of 36 workers employed in the manufacturing of leaded products used in radiologic safety was conducted. Although the principal source of lead exposure was limited to an area where two individuals mixed lead oxide and vinyl liquid, increased lead absorption was found in other workers employed in adjacent areas. The mean lead concentration of the plant workers was 29.3 micrograms/dL (SD +/- 9.0), and four workers had blood lead levels of 40 micrograms/dL or higher. A statistically significant correlation was noted between blood lead and serum creatinine; linear regression analysis demonstrated that cigarette smoking was a significant factor in predicting the blood lead level. The exposure encountered in this plant may be typical of lead exposure in many similar industrial settings. It calls attention to the risk of excessive exposure among workers who are not working at the primary source of exposure, and should be considered in the design of medical surveillance programs for workers employed in small manufacturing plants.