Concentration and health risk assessment of volatile organic compounds from a closed solid waste landfill site: The role of flaring system

Volatile organic compounds (VOCs) are emitted from landfills, posing health risks to landfill workers as well as nearby residents. This study aimed to assess the health risks associated with the Kuchino landfill near Moscow. The site was closed in 2017, and currently, reclamation and rehabilitation activities are underway by extracting the landfill gases and flaring them.The concentrations of VOCs were measured at the landfill site before flaring and at the edge of the nearby residential area after flaring. The measurements were performed by an accredited laboratory on a quarterly basis during 2020, adhering to relevant Russian and international standards. Measurements were conducted once each during the four seasons. Thirty VOCs were identified at the site and 20 at the nearby residential area. Risk calculations revealed that the workers at the landfill site were exposed to high carcinogenic (1.7 x 10-1) and non-carcinogenic risks (1.1 x 103). Carbon tetrachloride was the main contributor to both carcinogenic and non-carcinogenic risks, with 73.5% and 61% contributions, respectively. Regarding the health risks posed to the residents after flaring, the VOCs were found to exceed the acceptable limit for carcinogens (1.13 x 10-4) and remain within acceptable limits for non-carcinogens (9.23 x 10-1). Chloroform contributed 80% to potential carcinogenic risks and xylene contributed 57% to non-carcinogenic risks-both were principal contributors in their respective categories. The findings suggest the need for urgent mitigation actions to protect the health of workers and residents. Flaring is not a magical solution for VOCs emission; rather, flaring itself produces certain harmful VOCs.