Guidelines for inorganic arsenic (Ⅲ, V, and Total) and chromium (Ⅲ, Ⅵ, and Total) in Chinese soils.

Arsenic and chromium, common polyvalent heavy metals found in soil, are a growing environmental concern, yet research on soil threshold values for these metals is limited. This study presents a method for deriving soil guidelines based on published literature, considering two land types (parkland and industry), two exposure pathways (direct contact and food chain for mammalian and avian), and two toxicity levels (NOEC/LOAEL and EC50/LC50). Soil guidelines for inorganic arsenic (III & V) and chromium (III & VI) were derived separately for parkland and industry, factoring in direct contact and food chain exposures (applicable only to parkland) and both lower and upper toxicity levels from available data. The study discusses the similarities and differences between the proposed guideline values and international standards. Additionally, a new method is introduced for deriving soil guidelines for total arsenic and chromium, applicable to naturally occurring mixed valence states. Future research should refine these guidelines by addressing sample limitations, soil properties, and regional variations to enhance their accuracy and applicability in environmental management. Both methods can serve as references for managing other pollutants. These soil guideline values, particularly the total soil guidelines, offer valuable guidance for the Chinese government in managing arsenic and chromium levels in soil.