A Comparative Survey on Parameters Influencing on Hexavalent Chromium Measurement as an Occupational Carcinogen

Introduction & Hexavalent chromium, Cr+6, is a very harmful pollutant and a relatively unstable compound that is present in many industries. It is a known human respiratory carcinogen and occupational exposure to this chemical is associated with different health hazards. The purpose of this study was to evaluate the effects of four parameters including: type of sampling head, sampling height from the surface of electroplating solution, sampling duration, and sample storage duration on Cr+6 mist monitoring. To evaluate the influence of the main parameters as an experimental study, the 24 factorial design was applied at constant electroplating condition. A chromium electroplating bath with the ability to produce homogenous mist was used to create Cr+6 mist in laboratory setting. The National Institute for Occupational Safety and Health (NIOSH) method 7600 was used to determine the Cr+6 concentration. The results of 48 Cr+6 mist samples showed that Cr+6 concentration was higher: (1) for sampling by closed-face filter cassettes than for sampling by open-face filter cassettes (P<0.001); (2) for samples collected at 35 cm above the electroplating solution surface than for samples collected at 50 cm (P <0.001); (3) for sampling duration of 30 minutes than for sampling duration of 180 minutes (P <0.001); and, (4) for samples extracted immediately after sampling than for samples with delayed extraction (24 hours after sampling) (P <0.001). It is concluded that the accuracy of Cr+6 mist sampling in electroplating shops will be enhanced when: (1) a closed-face filter cassette is used to prevent liquid splash contamination; (2) the sampling height is suitable as determined by further research; (3) the sampling duration is short (approximately 30 minutes); and, (4) the extraction of the Cr+6 sample is performed as soon as the sampling is completed.