Аңдатпа
Aim: Occupational exposure to particulate matter (PM) in those working outdoors in polluted cities located in low-income countries is poorly characterized. The aim of this study was to assess exposure to PM10 in the ‘clean’ workplaces of outdoor workers in Almaty, Kazakhstan in a colder season as a result of fossil fuel use for heating. Material and Methods: In each of 10 outdoor security guards selected from different locations across Almaty, we collected eight 8-hour samples of PM10 with the overall sampling time 640 hours. Measurements were done daily in November 2018-February 2019 using personal aerosol TSI DustTrak AM520 monitors. We compared between- and within-person variability of PM10 8-hour time-weighted average (TWA) using ANOVA and calculated the exceedance (γ) and the probability of overexposure (θ) of the ambient TWA exposure limit (EL) (0.06 mg/m3), since occupational EL for PM10 does not exist in Kazakhstan. Results: 8-hour PM10 TWA ranged from 0.098 to 2.415 mg/m3 (geometric mean 0.430 mg/m3, median 0.448 mg/m3). All 8-hour TWA concentrations exceeded EL of 0.06 mg/m3, leading to γ=0.997 and θ=1.0. Despite very high within-person variances, F-ratio for ANOVA test was 2.36 (p=0.03), indicative of a greater between-person difference. Very high concentrations (2.415 and 2.075 mg/m3) were recorded in an industrial zone. Conclusions: Outdoor ‘clean’ jobs in polluted cities in winter expose outdoor workers to very high concentrations of PM10, and the risk is largely underestimated. Population should be made aware of very high risk in the outdoor workplaces in winter.