Occupational exposure to nickel, cobalt, and chromium in the Lithuanian hard metal industry

Background Metalworkers are said to have heavy exposure to metals, but the amount of released metal ions from alloys and deposition on the hands is unknown. Objective To analyze nickel, cobalt, and chromium in vitro release to the artificial sweat from nails and wire made of different alloys, and to test metal deposition on the fingers of metalworkers. Material and Methods Six different samples of nails and wire were kept in artificial sweat for 24 hours and one week, respectively. The metal release was determined by atomic absorption spectrometry (AAS). Eighty-eight consecutive metal plant workers immersed their index fingers and thumbs in separate laboratory tubes filled with deionized water for 2 minutes. The sample analysis for metals was carried out with an inductively coupled plasma mass spectrometer (ICP-MS). Results The average released concentration of Ni was 0.0012 mu g/cm(2), for Co it was 0.0007 mu g/cm(2), and for Cr 0.0037 mu g/cm(2) after 24 hours and 0.0135, 0.0029, and 0.0042 mu g/cm(2), respectively, after 1 week. There was a statistically significant increase in released concentration of Ni during one week: 0.0012 mu g/cm(2) vs 0.0135 mu g/cm(2) (P = .04). Medians of the detected Co amount on fingers reflected a statistically significant difference between workplaces: 0.004 mu g/cm(2) for metalworkers vs 0.001 mu g/cm(2) for office staff (P = .04). Conclusion Nickel (Ni), cobalt (Co), and chromium (Cr) can be released in different concentrations from nails and wire. Detected Ni and Cr levels can elicit dermatitis in already sensitized patients. Co can be extracted from alloys even if not mentioned on material safety data sheets. The finger immersion technique was used for cobalt and chromium detection on fingers for the first time.