Review of the Spatial Distribution, Source and Extent of Heavy Metal Pollution of Soil in China: Impacts and Mitigation Approaches

摘要

Background. China has undergone a rapid industrial revolution and urbanization duringthe past three decades. This expansion is largely responsible for the release of a large amountof heavy metals into soils and is increasingly raising concerns over the potential effects onhuman health and the environment. The problem is drawing increasing attention, especiallyafter an extensive nationwide soil survey report in 2014. A number of studies have examinedsoil contamination by heavy metals in China. However, most of these studies have been smallin scale and it is therefore challenging to get a general overview of the level of contaminationacross the entire country.Objectives. The present study is aimed at presenting a synthesized overview of the extent,pattern, and impact of heavy metal contamination of soils in China, including mitigationapproaches.Methods. Eighty-six journal articles and other literature such as reports, internet sources,and statistical yearbooks were narratively and critically synthesized to compile a holisticsummary of sources of heavy metals, the extent of pollution, spatial distribution and impactof heavy metal contamination in China. The major findings from these studies are presented,along with mitigation approaches applicable to China.Discussion. A synthesis of major findings from recent scientific journals shows that about10.18% of farmland soils which supports 13.86% of grain production in China is affectedby heavy metals. The main sources of pollution are anthropogenic activities. Even thoughthe spatial distribution of pollution is highly variable owing to natural and human factors,provinces with intensive industrial activities such as Henan, Shandong, and Sichuan are morehighly polluted than others. These regions are top grain producing areas and hence requireclose follow-up for development of feasible approaches to mitigating crop contaminationand associated health risks emerging in parts of China. The government recently launched aprogram aimed at determining sound reclamation strategies.Conclusion. Mitigation of heavy metal contamination in China requires coordination ofdifferent actors and integration of all feasible reclamation approaches.Keywords: soil, heavy metals, contamination, pollution, reclamation, remediation,bioremediationCompeting Interests. The authors declare no competing financial interests.