Follow-up of biologic monitoring results in cadmium workers removed from exposure

Biological monitoring and exposure monitoring data for employees at a nickel-cadmium battery production facility were made available to OSHA for review. Sixteen employees were medically removed from occupational exposures to cadmium due to elevated levels of biological parameters (CdB, Cdu, B₂U). While the biological monitoring parameters for most workers significantly declined during the 18 months of medical removal, the biological parameters for only one employee's values returned to the normal range. Only one worker had frank renal dysfunction, based on beta-2-microglobulin levels at the time of removal; this dysfunction remained throughout the 17 months of observation after medical removal. Significant policy implications of medical removal protection beyond the current 18-month period provided by the cadmium standards exist and require physician discretion. Mitigating issues which may make it ethically appropriate to return an employee to work despite elevated biologic monitoring parameters are also discussed.