Occupational exposure to respirable crystalline silica in municipal household waste collection and road cleaning workers

Abstract

Despite the increase in the number of cases among South Korean sanitation workers, lung cancer as a result of exposure to occupational carcinogen has not been sufficiently investigated. This study aimed to identify exposure levels of sanitation workers to respirable crystalline silica (RCS) for various tasks and factors that affect individual RCS exposure. Exposure to RCS was assessed for 90 sanitation workers from seven companies. The obtained geometric mean value of the RCS was 2.6 µg m^-3, which is a similar level to recommendations set by California's Office of Environmental Health Hazard Assessment's Recommended Exposure Limit. Meanwhile, coal briquette ash (CBA) collectors exhibited the highest RCS concentration (24 µg m^-3), followed by road cleaning workers who used a blower, municipal household waste collectors, sweepers, and drivers (p < 0.05). Additionally, when the ANOVA was conducted, statistically significant differences were observed in RCS concentrations among various factors such as job task, season, employment type and city scale. Our study confirmed that sanitation workers who work outdoors could be exposed to RCS. Due to the possibility of exposure to high RCS concentrations, special attention should be paid to the collection of used CBA and road cleaning involving the use of a blower.

Figure 1

Tasks of the sanitation workers in this study. (a) loading general garbage in a truck, b: Loading CBA in a truck, (c) loading recyclable garbage in a truck, (d) driver of garbage truck, (e) sweeping the road, (f) Picking up trash, g: air blowing fallen leaves, (b) air blowing road sand, (i) the CBA is manually loaded onto the truck, and the truck automatically unloaded the CBA. (j) Manually loading and unloading briquettes into a truck.

Figure 2

Box chart with data points overlap. Exposure level of respirable crystalline silica (RCS) by various tasks. Cleaning of fallen leaves and road sand uses a blower.