Heavy metal(loid)s pollution in soils of a typical agricultural and rural area: Source apportionment and derived risk quantification

In light of the pervasive contamination of soils with heavy metals (HMs) on a global scope, the precise identification and assessment of sources and areas of contamination are crucial for the effective management and utilization of land. This study combines several models to quantitatively apportion possible sources of HMs and environmental risks in agricultural and rural areas of Langfang City, Hebei Province. The findings indicate that the accumulation of HMs is influenced by human activities, with varying degrees of accumulation observed. The Positive Matrix Factorization (PMF) model identified five sources, with the order of magnitude of their contributions to the soil HMs content being as follows: coal combustion source (24.9%), industrial activities source (23.1%), agricultural activities source (19.2%), natural source (16.6%), and traffic emissions source (16.3%). The ecological risks present in the study area are not significant; however, the human health risks exceed the acceptable limits. The primary sources of pollution that pose a risk to human health are industrial, followed by natural source. As, Cr and Ni were responsible for the non-carcinogenic risk, while Cr was the dominant factor in the carcinogenic effect. The risk distribution map indicates that the areas exhibiting the highest risk are situated in the east-central region of the study area. This study had identified the priority control factors (including HMs, sources of pollution and high-risk areas) for the use and management of the land.