To evaluate workers' exposure to arsenic and gallium arsenide and health conditions in a gallium arsenide processing enterprise.

Following the Specifications of Air Sampling for Hazardous Substances Monitoring in the Workplace(GBZ 159-2004), 147 arsenic and gallium arsenide air samples in 29 sampling points were collected. Occupational health examinations were conducted according to the Technical Specifications for Occupational Health Surveillance(GBZ 188-2007), and surveys included medical history, occupational history, and family history of diseases. SPSS 17.0 software was applied to analyze the workplace monitoring results and 327 workers' occupational health examination results through chi-square test and rank sum test.

The unqualified rate of 80 arsenic air samples was 3.8%. Of the 67 gallium arsenide samples, 35 samples exceeded the time weighted average threshold recommended by American Conference of Governmental Industrial Hygienists (ACGIH) (0.000 3 mg/m³) and the unqualified rate was 52.2%. No nervous system or urinary arsenic abnormalities were reported, the median of urinary arsenic level was 6 μg/L, and the mean rank of urinary arsenic level in male workers (174.7) was reported higher than that of female workers (145.6) (χ²=7.237, P < 0.05). The detection rate of skin abnormalities was 2.5%, and all involved workers' seniorities were more than 5 years. No statistically significant differences were observed among the workers categorized by seniority in the abnormal rates of skin, serum alanine aminotransferase (ALT), and serum total bilirubin. The abnormal rates of serum total bilirubin in 5-10 years seniority group and ALT in < 5 years and 5-10 years seniority groups in male workers were higher than those in female. No higher abnormal rates of skin, serum total bilirubin, and ALT were found for the workers in the workshop with concentrations exceeding standards than for those in the workshop with qualified concentrations.

In the enterprise investigated, most workers are exposed to low concentrations of arsenic and show skin damage and ALT abnormalities, and only a small part of workers performing specific tasks are exposed to relative high concentrations of arsenic. Therefore, the enterprise should pay attention to the health conditions of workers on key positions.