A review of soil cadmium contamination in China including a health risk assessment

Abstract

Cadmium (Cd) is one of the most serious soil contaminants in China, and it poses an increasing risk to human health as large amounts of Cd are emitted into the environment. However, knowledge about soil Cd concentrations and the human health risks of these concentrations at a national scale is limited. In this study, we conducted a review of 190 articles about soil Cd concentrations during 2001 to 2010. The study involved 146 cities in China, and we quantified the risks to human health according to different regions. The results showed that elevated Cd levels were present compared to the background value of soil in 1990, and the soil Cd concentrations in the Guangxi province exceeded even the class III Soil Environmental Quality standard, which is the limit for the normal growth of plants. The Chinese soil Cd concentrations ranged from 0.003 mg kg(-1) to 9.57 mg kg(-1). The soil Cd concentrations had the following trend: northwest > southwest > south central > east > northeast > north. The sources of soil Cd are mainly from smelting, mining, waste disposal, fertilizer and pesticide application, and vehicle exhaust, etc. but differentiated in various regions. The soil Cd contamination in urban areas was more serious than contamination in the agricultural areas. Currently, there is no significant non-carcinogenic risk in any of the provinces. Regarding the different exposure pathways, the dermal pathway is the primary source of soil Cd exposure, and the risk associated with this pathway is generally hundreds of times higher than the risk for an ingestion pathway. For most of the provinces, the health risk to the urban population was higher than the risk to the rural population. For each population, the carcinogenic risk was less than 10(-6) in most of the provinces, except for the urban population in the Hunan province. If the other exposure pathways are fully considered, then the people in these areas may have a higher carcinogenic risk. This review provides a comprehensive assessment of soil Cd pollution in China, and it identifies policy recommendations for pollution mitigation and environmental management in the relevant regions.

Hyperspectral‐based Inversion of Heavy Metal Content in the Soil of Coal Mining Areas

“…The soil content of the heavy metals studied ranged from 0.038 to 225.7 mg kg −1 (Table 2). The mean values (across all soil samples) were all lower than the Chinese national soil environmental quality standard (Wang et al, 2015). One sample point of Ni and three sample points of Cd exceeded the national secondary standard for soil environmental quality.…”

A pilot study for construction of a new cadmium-sensing yeast strain carrying a reporter plasmid with the <i>JLP1</i> promoter

“…Although the adverse health effects of Cd are wellknown and the underlying mechanisms have been disclosed in degrees (see our review: Koedrith and Seo, 2011;Kwon et al, 2013;Kim et al, 2015), exposure to Cd is still being reported in some parts of the world (Ikeda et al, 2004;Pan et al, 2010;Waseem et al, 2014;Wang et al, 2015;Johnson et al, 2016). In addition to its discharge from mines, the emission of Cd has markedly increased since the late 20th century.…”

The effectiveness of nanobiochar for reducing phytotoxicity and improving soil remediation in cadmium-contaminated soil

“…It was reported by the Ministry of Environmental Protection, P. R. China, that as of 2014, 7% of all cultivated areas contained Cd-contaminated soil. There is growing concern regarding Cd contamination because excess Cd exposure can directly cause both noncarcinogenic and carcinogenic risks 2 . Cd in soils can be readily taken up by plant roots and transferred to aboveground plant parts, resulting in phytotoxicity, which will indirectly cause a threat to animal and human health through the food chain [2][3][4][5] .…”