The study aimed to investigate the impacts of coal mining-contaminated soil on the locally grown food crops and humans health. For the active investigation and assessment, the study collected 175 samples including contaminated and control soil and various types of food crops (corn, wheat, mixed food (egg, pork meat, potato, pepper)) from Shaanxi Province. All these samples were analyzed through ICP-MS and ICP-OES. Results show that in Weibei soil, the average concentration (mg kg-1) of Cr (194 ± 94), Cu (27 ± 13), Cd (0.6 ± 0.3), Ni (83 ± 35), Be (1.98 ± 0.8), Rb (115 ± 68), Li (74 ± 78), Sr (148.5 ± 67), and Zn (3056 ± 2380) was higher than that of the Chinese soil standard (CSS) and upper continental crust (UCC) (P < 0.01-0.05). In Langao soil, the average concentration (mg kg-1) of Cr (99.5 ± 48), Cu (77 ± 32), Ni (113 ± 37), Pb (45 ± 19.8), Cd (2.9 ± 1.7), Co (13.9 ± 2.4), Mo (28.7 ± 16), Be (2.98 ± 0.5), Li (81.8 ± 9.7), V (430 ± 166), Zn (255 ± 105), and Ba (1347 ± 445) was higher than that of the CSS and UCC. However, in Binxian Jurassic all the toxic trace elements (TTE) were higher than the CSS and UCC. In Langao contaminated vegetable, Na, Cd, Tl, In, Mo, Li, U, Bi, and Th may cause very high risk, whereas Al, Mn, P, Fe, Ca, Cr, Ni, Pb, Co, Cs, Rb, and Ba may cause considerable risk. However, the average daily intake (ADI) of Al, Mn, P, Fe, Cd, Mo, and Ba was higher than the No Observable Adverse Effect Level (NOAEL). However, the non-carcinogenic risk of Al, Mn, P, Fe, Cr, Cu, Ni, Pb, Cd, Co, Tl, Mo, Li, V, Ba, and Th was higher than acceptable level (HQ = 1). In Binxian wheat, Al, Tl, Cs, Bi, and Th may cause very high risk, and Ti, Na, K, Fe, Ca, Cr, Ni, Cd, Pb, Sr, Bi, and U may cause considerable risk. However, ADI of Al, Mn, P, Ti, Fe, Cu, Ni, Pb, Mo, Ba, and U for both adults and children was higher than the NOAEL. In Weibei, the wheat crops are prone to considerable-to-moderate elemental risk. The non-carcinogenic risk of Al, Mn, P, Fe, Cr, Cu, Pb, Co, Tl, Mo, Li, Zn, and Th was higher than the acceptable level. In countryside adults and children, ADI was lower than the NOAEL except Al, P, and Zn. The study concluded that human activities of coal mining release a high amount of TTE to the soil. Majority of arable land, grain food and vegetable were contaminated through TTE, which may cause high risks to human's health and the environment.
Keywords: Cambrian shale; Carboniferous belt; Food crops; Geochemistry; Health risk; NOAEL.