ABSTRACT
Heavy metal emission to the workplace and environment is a major health problem due to human activity posing a serious threat to the public especially to those working in manufacturing industries and consumers. Thus, this study was conducted with the aim of extent of worker's exposure to heavy metals in zinc melting industry in Zanjan during 2002-2004. This descriptional study was conducted in 6 industrial units of Zanjan through which airborne heavy metals concentrations including lead, zinc, cobalt, cadmium and nickel were measured. Measurements were performed based on National Institute of Occupational Health [NIOSH] 7300 method, using closed-filter cassettes, ester cellulose filter with pore size of 0.8 micro m followed by atomic absorption spectrometry [AAS] analysis, and the data were analyzed statistically using SPSS software version 11.5. The mean value of worker's exposure to heavy metals including Pb, Zn, Co, Cd, and Ni were 0.058, 2.518, 0.0025, 0.003, and 0.0108 mg/m[3] respectively. According to the obtained results 25% of the workers were exposed to lead higher than threshold limit values [TLVS]. However, worker's exposure to combined concentrations of different heavy metals [heavy metal mixed exposure] showed that more than 75% of the workers were exposed to heavy metals concentrations higher than TLV. In spite of short history of zinc melting industry in Zanjan [under 15 years] and young age of workforce, exposure of many workers to heavy metals concentration of higher than standard value increases the possibility of occupational diseases in the coming years. Thus, in order to protect national and human resources, preventive measures such as worker's health monitoring and control techniques are highly recommended