An occupational hygiene assessment of dermal nickel exposures in primary production and primary user industries

The object of this study was to measure the levels of soluble and insoluble nickel in the skin contaminant layer of nickel refinery workers and primary users of nickel products. This work followed on from initial investigations carried out in two nickel refineries, which was reported as Phase 1 of this study in IOM Technical Memorandum TM/04/05. For Phase 2 of this study, workplace surveys were carried out in one nickel refinery, a stainless steel production plant and a company involved in the production of AlNiCo magnets. The main task of interest for these sites were packing of nickel chloride crystals (nickel refinery), handling nickel metal briquettes and nickel cathodes (stainless steel production) and handling nickel powder products (magnet production), although in all three sites additional tasks were monitored. Dermal exposure samples were collected using a removal method, using commercial moist wipes to recover nickel deposits from measured areas of skin. The test procedure was the same as that used during Phase 1 and had a combined nickel recovery efficiency for the sample preparation and analysis of approximately 95% for insoluble nickel and 87% for soluble nickel compounds. A total of 33 sets of dermal exposure measurements were collected from 29 different workers. Of the total 755 dermal exposure measurements, 140 were less than the LOD of 0.02 ?g/cm2. The highest actual dermal exposures were recorded for the nickel refinery workers and a subgroup of workers in magnet production who had direct contact with nickel powder. In these cases the workers��� hands, arms, face and neck all received more surface contamination compared with other jobs. In the case of the nickel chloride packers, the median and 90th percentile combined hand/arm dermal total nickel exposures were 4.01 and 10.86 ?g/cm2. The corresponding results for the nickel powder exposed workers in the magnet company were 4.56 and 19.69 ?g/cm2. In the latter case the levels of soluble nickel on the skin were much lower than nickel chloride workers, which is due to the relatively low solubility of the nickel powders used in this industry. The nickel exposures for the workers in the stainless steel production plant were very low, which was mainly due to the use of mechanical handling methods for the nickel metal being used in the process.