Characterization of airborne microplastics at different workplaces of the poly(ethylene:propylene:diene) (EPDM) rubber industry

Microplastics (MPs) as an emerging air pollutant have received widespread attention, but research on airborne MPs at occupational sites is still limited, especially in the rubber industry. Hence, indoor air samples were collected from three production workshops and an office of a rubber factory producing automotive parts to analyze the characteristics of airborne MPs in different workplaces of this industry. We found MP contamination in all air samples from the rubber industry, and the airborne MPs at all sites mainly showed small-sized (< 100 mu m) and fragmented characteristics. The abundance and source of MPs at various locations is primarily related to the manufacturing process and raw materials of the workshop. The abundance of MPs in the air was higher in workplaces where production activities are involved than in office (360 +/- 61 n/m(3)), of which the highest abundance of airborne MPs was in the post-processing workshop (559 +/- 184 n/m(3)). In terms of types, a total of 40 polymer types were identified. The post-processing workshop has the largest proportion of injection-molded plastic ABS, the extrusion workshop has a greater proportion of EPDM rubber than the other locations, and the refining workshop has more MPs used as adhesives, such as aromatic hydrocarbon resin (AHCR).

Automated summary

This study collected and analyzed indoor air samples from different workshops and an office of a rubber factory to investigate the characteristics of airborne microplastics (MPs) in the rubber industry. MPs contamination was found in all air samples, with small-sized and fragmented characteristics. The abundance and sources of MPs were primarily related to the manufacturing process and raw materials of the workshops. The post-processing workshop had the highest abundance of airborne MPs, and different polymer types were identified in each location.