To clarify the characteristics of Cd, As, and Pb concentrations in edible parts of crops and farmland soils, a key farmland survey was conducted on the field scale to investigate the characteristics of Cd, As, and Pb in soil and chili pepper （edible parts in the above-ground section） and sweet potato （edible parts under the ground） and assess the health risk of Cd-As-Pb in edible parts of chili pepper and sweet potato to humans in the typical co-contaminated agricultural soils by Cd, As, and Pb from metal smelting and sewage irrigation in North China. The results showed that the agricultural soil from chili pepper and sweet potato fields was co-contaminated by Cd and As at a moderate pollution level. The combined pollution index （2.82） of soil from sweet potato farmland was significantly higher than that from chili pepper fields （2.38） for sweet potato land much nearer to the pollution sources （P<0.05）. However, Cd concentrations in edible parts of chili pepper exceeded the safety limitation of 0.1 mg·kg-1 in the national standard of "Green food pepper products" （NY/T 1711-2020）, but the concentrations of Cd, As, and Pb in edible parts of sweet potato did not exceed the "National food safety standard food pollutant limit" （GB 2762-2022）. Additionally, the bioaccumulation factors （BAFs） of Cd, As, and Pb in edible parts of chili pepper to soil were markedly higher than those of sweet potatoes, especially for Cd, which showed the maximum of the BAFs for chili pepper. Therefore, BAFs could be the key factor in Cd accumulation in the fruits of chili peppers. The risk assessment of Cd and As as the carcinogenic elements in edible parts of chili pepper and sweet potato to human health demonstrated that Cd in the whole fruit of chili pepper had posed a significant health risk to adults （Ri>1×10-4）, and it was an acceptable level of health risk from Cd and As in edible parts of both crops to children. The non-carcinogenic element of Pb in the fruits of both crops did not cause health risks to adults or children. In summary, the chili pepper products from this co-contaminated farmland by Cd and As would pose risks to human health, and the sweet potato products would cause acceptable health risks to humans.
Keywords: cadmium（Cd）-arsenic（As）-lead（Pb）; chili pepper; co-contaminated farmland by heavy metals; contamination characteristics; health risk; sweet potato.