Non-carcinogenic risk assessment of occupational exposure to hexavalent chromium in two selected types of chrome electroplating workshops in Tehran

Background and aims: There are increasing evidences for the toxicity of hexavalent chromium compounds. In the present research, occupational exposure to hexavalent chromium in the electroplating industry was studied. The corresponding non-carcinogenic risk was also assessed in two types of chrome electroplating workers.
Occupational exposure to hexavalent chromium was evaluated in eighteen decorative and hard chromium electroplating workshops in Tehran, Iran. About 35 hard chromium electroplaters and 30 workers from decorative chrome electroplating workshops were studied. NIOSH 7600 was used to assess occupational exposure to hexavalent chromium. Non-carcinogenic risk assessment of hexavalent chromium was performed according to EPA reference dose. Ethical issues such as confidentiality of information and the announcement of results to the participants were all considered in all stages of research.
The median hexavalent chromium concentration in studied workshops was 0.02 mg/m3, with the maximum occupational exposure of 0.096 mg/m3 in A7 related to hard chrome electroplating and the minimum level of 0.019 mg/m3 in B6 from decorative chrome electroplating workshops. The results of this study further showed that exposure to hexavalent chromium in the hard chromium electro plating workshops was significantly (p≤0.0001) higher than decorative chrome plating workshops. Non-carcinogenic risk of hard chrome electroplaters was 6 times higher than decorative chrome electroplating workers.
Airborne exposure to hexavalent chromium in the studied chrome electroplating workshops is lower than limit standard of occupational exposure, but non-carcinogenic risk is higher than acceptable level.