This paper is the result of environmental geological survey engineering.

Objective To investigate the thallium content characteristics and pollution status of soil in the eastern mountainous area of Nanyang Basin, and to assess the health risks of thallium to the human body.

Methods Soil thallium in the study area was analyzed by multivariate statistical analysis, enrichment coefficient method, soil accumulation index method and health risk assessment method.

Results The average Tl values of surface and deep soil in the eastern mountain area of Nanyang Basin were 0.61 and 0.65 mg/kg, respectively. The high Tl content in surface and deep soil was mainly distributed in acid granite and metamorphic rock in the study area. The concentration coefficient showed that 96.15% of surface soil Tl samples were clean and 3.85% were mildly enriched. The soil accumulation index showed that 97.53% of surface soil Tl samples were pollution−free and 2.47% were lightly polluted. The results of health risk assessment showed that the total hazard quotient HQ index of non−carcinogenic risk for adults and children was less than 1, and there was no non−carcinogenic health risk of soil Tl.

Conclusions The parent material of the study area not only determines the content level of Tl in the soil, but also influences the spatial distribution of thallium.