Occupational exposure to arsine. An epidemiologic reappraisal of current standards.

In an evaluation of chronic occupational exposure to arsine (AsH3), an epidemiologic survey was conducted at a lead-acid battery manufacturing plant. Personal (breathing zone) air samples were obtained for the measurement of exposure to arsine and particulate arsenic (As), and area air samples were also collected for the determination of arsenic trioxide (As2O3) vapor concentrations. For the quantification of arsenic absorption, total arsenic content was determined in duplicate 24-h urine samples. Arsine in 177 breathing-zone air samples ranged from nondetectable to 49 micron/m3. The highest levels were found in the battery formation area, where arsine is generated by the reaction of battery acid with lead-arsenic alloy. Exposures to particulate arsenic (maximum 5.1 micron/m3) and to As2O3 (maximum (20.5%) of 39 production workers had urinary arsenic concentrations (corrected to a specific gravity of 1.024) of 50 micron/1 (0.67 mumol/1) or above, indicating increased arsenic absorption. None of eight office staff had elevated urinary arsenic levels. A close correlation was found between urinary arsenic concentration and arsine exposure (N = 47; r = 0.84; p = 0.0001). Arsine levels above 15.6 micron/m3 were associated with urinary arsenic concentrations in excess of 50 micron/1 (0.67 mumol/1). No correlation was found between urinary arsenic content and exposures to particulate arsenic or to As2O3. Consumption of neither seafood, red wine, tobacco, nor contaminated drinking water accounted for urinary arsenic excretion. It was concluded that the current arsine exposure standard, 200 micron/m3, fails to prevent chronic increased absorption of trivalent arsenic from the inhalation of arsine.