Assessment of particulate matter exposure and associated human health risk: Comparison among non-automated, automated and semi-automated rice processing plant workers

Exposure to particulate matter (PM), specifically PM 2.5 and PM 10 , poses significant health risks, particularly to workers in industries such as rice processing, where dust and particulate emissions are prevalent. This study aimed to investigate exposure to PM 2.5 and PM 10 among rice processing industry workers and the associated health risks in the Kushtia District of Bangladesh. A total of 180 indoor and outdoor PM samples were purposively collected from three types of rice processing plants: automated, semi-automated, and non-automated, using a widely used handheld particle counter device (Model HT 9600). The study found the concentration of indoor PM 2.5 of 43–181 µg/m 3 , indoor PM 10 of 57–207 µg/m 3 , outdoor PM 2.5 of 47–160 µg/m 3 and outdoor PM 10 of 61–203 µg/m 3 . All rice processing plants exhibited higher levels of PM 2.5 and PM 10 , exceeding the World Health Organization (WHO), the National Ambient Air Quality Standards (NAAQS) and Bangladesh standards. The hazard quotient (HQ) for PM 2.5 exceeded 1, indicating significant health risks across automated, non-automated and some semi-automated rice processing plants, with the automated and non-automated plants posing the greatest concern. The results showed that the PM levels in indoor and outdoor air in the study area were markedly high. This study concluded that both PM 2.5 and PM 10 exposure increased workers' health risks. Future research should identify workplace PM sources and explore mitigation strategies for workers.