cancer risk assessment in welder's under different exposure scenarios.

welders exposure to nickel and hexavalent chromium in welding fumes is associated with increase of cancer risk in welders. in this study we calculated cancer risk due to exposure to these compounds in welders.the role of exposure parameters in welders on derived incremental lifetime cancer risk were determined by stochastic modeling of cancer risk. input parameters were determined by field investigation in iranian welders in 2013 and literature review.the 90% upper band cancer risk due to hexavalent chromium and nickel exposure was in the range of 6.03e-03 to 2.12e-02 and 7.18e-03 to 2.61e-02 respectively. scenario analysis showed that asthmatic and project welders are significantly at higher cancer risk in comparison with other welders (p<0.05). shift duration was responsible for 37% and 33% of variances for hexavalent chromium and nickel respectively.welders are at high and unacceptable risk of cancer. control measures according to scenario analysis findings are advisable.