Objective To investigate the hygienic status of soil and rice in rural areas of Jiangsu Province, China, and to provide a reference for soil pollution risk management and soil remediation in the future.
Methods Based on the principle of multistage random sampling, field investigation was performed and determination of lead, chromium, cadmium, mercury and arsenic contents was measured for the farmland soil and rice in 26 agricultural districts and counties in Jiangsu Province. Analysis and evaluation were carried out respectively in southern, central and northern of Jiangsu Province. The results of heavy metals in soil was evaluated in accordance with the Soil Environmental Quality-Risk Control Standard for Soil Contamination of Agricultural Land (GB 15618-2018), and the results of heavy metals in rice was evaluated in accordance with the National Food Safety Standard-Limits of Contaminants in Food (GB 2762-2017).
Results A total of 1 560 soil samples were investigated, and the qualified rate of lead contents in soil was 99.55% (1 553/1 560) in Jiangsu Province. The qualified rate of chromium contents in soil was 99.81% (1 557/1 560), and the unqualified soil samples with chromium contents were collected from southern of Jiangsu. The qualified rate of arsenic contents in soil was 99.71% (1 037/1 040), and the unqualified soil samples with arsenic contents were collected from northern of Jiangsu. The qualified rate of cadmium contents was 96.67% (1 508/1 560), with relatively low qualified rates of 96.33% in southern of Jiangsu and 95.50% in northern of Jiangsu. The qualified rate of mercury contents was 97.88% (1 018/1 040). A total of 1 554 rice samples were analyzed. The qualified rate of lead contents in rice was 99.87% in the province, and the unqualified samples were collected from central of Jiangsu. The qualified rates of cadmium, chromium, mercury, and arsenic were 99.23%, 98.91%, 99.42%, and 99.61%, respectively, and the unqualified samples of arsenic were collected from central of Jiangsu. One-to-one correspondence was observed between soil lead concentration and rice lead concentration, between soil cadmium concentration and rice cadmium concentration, and between soil arsenic concentration and rice arsenic concentration, which was statistically significant (P < 0.001, P=0.013, P=0.005).
Conclusion There are relatively low pollution levels of the heavy metals, such as lead, chromium, mercury, and arsenic, in soil and rice of Jiangsu Province. However, the heavy metal cadmium pollution is heavy in some areas, and the concentrations of lead, cadmium, and arsenic in rice are correlated with those in soil.
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