Objective The aim was to provide reference basis for environmental assessment and health risk assessment of 16 dominant polycyclic aromatic hydrocarbons (PAHs) in paddy soils from 9 regions in Guizhou Province.

Methods The contents of polycyclic aromatic hydrocarbons (PAHs) of 72 paddy soil samples in 9 regions in Guizhou Province were determined by gas chromatography triple quadrupole mass spectrometer with selected ion mode.

Result The paddy soils in Guiyang, Tongren, Liupanshui, and Qianxinan areas were moderately polluted by PAHs, while the paddy soils in Zunyi and Bijie areas were severely polluted. The proportions of high molecular weight polycyclic aromatic hydrocarbons (HMW PAHs) in Guiyang and Zunyi regions were 79% and 85%, which was higher than that in other regions. The characteristic ratio and principal component analysis results showed that petroleum and its combustion sources, as well as biomass fuel combustion sources such as coal, were the main sources of PAHs pollution in paddy soils. The health risk assessment results indicated that skin contact had a higher risk of cancer than other exposure pathways. PAHs in paddy soils from five regions in Guizhou, including Guiyang, Zunyi, Bijie, Qianxinan and Anshun, could pose a potential carcinogenic risk to children through oral ingestion and skin contact.

Conclusion The rapid increasing number of automobiles in Guizhou in recent years, and the extensive use of coal mining had caused a long-term cumulative PAHs pollution and increased proportion of PAHs in paddy soils in Guizhou Province, which posed a potential cancer risk to children. Therefore, corresponding measures should be taken to reduce pollution sources and the degree of paddy soil pollution.