Heavy metal pollution in the soil around municipal solid waste incinerators and its health risks in China

Objective: In China, municipal solid waste (MSW) incineration (MSWI) has been increasing in recent years. However, little is known about how the operation of incinerators can affect levels of heavy metals (HMs) in nearby soils or about the possible associated health risks. It is necessary to understand the degree of enrichment of HMs and health risks to people living nearby. Methods: Previous studies (2002-2021) regarding soil HMs near MSW incinerators were collected, and a cluster and factor analysis was used to evaluate the accumulation trends and distribution characteritics of HMs. The soil contamination degrees and the consequent health risks were then assessed. Results: Cd (0.24 +/- 0.16 mg kg(-1)) is typically accumulated in the topsoil near incinerators, and this is followed by Hg (0.13 +/- 0.09 mg kg(-1)). Most of the health risk due to the total HMs is derived from dermal contact. Dermal contact with Cd and As contributes to more than 67% of the non-carcinogenic risk, while dermal contact with As contributes to more than 99% of the carcinogenic risk (CR). Furthermore, 81.43% of adult males and 76.85% of adult females suffer from CR levels greater than 10(-4) due to dermal exposure to As. Conclusions: Soils near incinerators indicated light pollution and moderate potential ecological risk, especially with regard to Cd and Hg contamination. Undeniably, there was no significant difference between the health risks from soil HMs near incinerators and from arable land at the national level. It is suggested to reduce the input quantity of HMs by taking advantage of the nationwide implementation of MSW classification and upgrading air pollution control devices for further HM emission reductions.

Automated summary

The study found that soils near incinerators are contaminated with heavy metals, particularly Cd and Hg, posing certain health risks. Improving the operation of incinerators and reducing the emissions of heavy metals are key to reducing pollution and health risks.