Objective The aim was to investigate the status and sources of heavy metal pollution in soil in an industrial park.

Method The contents of Cr, Cu, As, Cd, Zn, Pb and Ni in the soil around the main factory in an industrial park were detected and analyzed. Based on the soil background value of Qinghai Province, geo-accumulation index, pollution load index and health risk assessment methods were used to evaluate heavy metal pollution, and multivariate statistical analysis method and absolute principal component multiple linear regression (APCS-MLR) model were used to quantitatively analyze the pollution sources.

Result The average content of seven heavy metals exceeded the background value of soil in Qinghai Province, and Zn, As and Cd exceeded the soil pollution risk screening value of agricultural land, and the contents of all elements had high values in the eastern part of the study area. The evaluation results of the geo-accumulation index showed that 75% of the sampling points were polluted, and the Cd pollution was the most serious. The average value of the evaluation results of the pollution load index reached the intensity pollution, and all the sampling points were moderately polluted or above. The health risk assessment showed that the non-carcinogenic risk of adults and children was ranked As Cr > As > Pb > Cd > Ni > Cu > Zn, and there was a certain non-carcinogenic risk, and the carcinogenic risk of children (2.89 × 10⁻⁴) > adults (8.13 × 10⁻⁵), and As was the element with the largest contribution rate to carcinogenic risk. There are three main pollution sources of heavy metals in the soil of the study area, which are the sources of industrial production activities (25.5%), the combined source of industrial production activities and natural factors (55.5%) and the traffic source (18.0%).

Conclusion The industrial park had the largest area and the heaviest degree of soil contaminated by Cd. The evaluation results showed that the soil in the park had reached the level of moderate pollution or above on the whole, and the contribution rate of carcinogenic risk of As was the largest. The source analysis results showed that the pollutants mainly came from industrial production activities and should be prevented.