PAHs in the priority list were all detected in soil
15 PAHs in the priority list were all detected in
Concentrations of PAHs in 33 samples were presented in Table S3 and
cancer risk of human exposure to PAHs is also lacking.
the descriptive statistic was shown in Table 1. It was clear that the total
The objectives of the present study were to (1) measure the contents
of PAHs in the surface 205391-01-1 from the Shanxi province, China, (2) identify
the possible sources of PAHs, and (3) assess the human cancer risk of
the 33 samples, the lowest concentration was found in Jincheng city,
soils contaminated by PAHs via ingestion, dermal contact, and inhala-
whereas the highest was the Changzhi city. The assessment of soil
contaminated by PAHs was classified into four categories (Maliszewska-
2. Materials and methods
2.1. Study area and soil collection
samples were presented as non-contaminated, 21% as weakly con-
As shown in Fig. 1, 33 soil samples were averagely distributed at the taminated, 27% as contaminated, and 21% as heavily contaminated soil
in the present study. The heavily contaminated areas were mainly lo-
11 cities in Shanxi province, China in 2018. These samples were col- cated at Datong, Xinzhou, Changzhi, and Linfen areas.
lected from the farmlands near the residents’ houses. All samples were And seven PAHs have been highlighted due to the potential human
freeze-dried at ̶50 °C for one day, sieved to 60 mesh size particles to carcinogens (B2 group PAHs containing 4- to 6-rings fused benzene
remove, and stored in amber glass containers until analysis.
rings), including benz[a]anthracene, chrysene, benzo[b]fluoranthene,
anthracene. Among the priority 15 PAHs, the levels of seven carcino-
Organic pollutants were extracted by the Soxhlet extractor, and the genic PAHs ranged from 33.2 to 1181 ng/g dw with a mean of 367 ng/g
chemical analysis of 15 priority PAHs (Table S1), except for naphtha- In general, PAHs dominated by high molecular weight (HMW) PAHs,
lene due to the wide spread in air, w as carried out using gas chroma- which accounted for half of the total. These results were in accordant
tography-mass spectrometry. Detailed information on the chemical re- with the literature reported that HMW PAHs are mainly tend to accu-
agents, the quality control and quality assurance for chemical analysis mulate in the soil by the dry and wet deposition of ambient particles
were shown in the supporting information (SI).
and finally remain in the soil through absorption, adsorption, and se-
As shown in Table 2, the average level of the priority PAHs (732 ng/
g) in agricultural soil of Shanxi province was much higher than those in
The ILCRs exposed to PAH-contaminated soil were calculated by the rural soil, such as Novi sad (363 ng/g) of Serbia, Ahvaz (173 ng/g) of
targeted, chemical-specific approach. The population numbers were Iran, Beijing (219 ng/g) and Shanghai (360 ng/g) of China. But it was
divided into six groups according to age and gender, included child- lower than those in urban areas, such as London (18,000 ng/g) of UK,
hood, adolescence and adulthood correspond to male and female, re- Campania (1392 ng/g) of Italy, Nanjing (1060 ng/g), Changchun
ingestion, dermal and inhalation according Equation (1) to (3) based on the previously reported, the PAH concentrations in Shanxi province
were much higher at industrial areas and in the vicinity of chemical
ingestion = Csoil × IngR × EF × ED × CF × SFO/(BW × AT) (Table 2). But the average concentrations in agricultural areas were
lower generally than those for industrial areas, such as Xinzhou
The divergence of economic development was the main reason for
PAHs distribution in the soil of China. There were higher concentrations
Concentrations of polycyclic aromatic hydrocarbons (PAHs) from the surface soil in Shanxi province in 2018 (ng/g dry weight, dw, n = 33).
Acronym Contaminant TEFa DFb (%) Minimum Median Maximum Mean
7C BaPeq e
Sum of BaPeq
a TEF: toxic equivalence factor. The TEF values were derived from the literature (Nisbet and Lagoy, 1992; USEPA, 1993).
b DF: detected frequency.
c Reporting limits for individual contaminants are 0.50 ng/g dw.
d Sum of seven carcinogenic PAHs (BaA, Chr, BbF, BkF, BaP, IcdP, and DahA).
e BaPeq: Benzo[a]pyrene equivalent concentrations calculated by TEF.
in Eastern China and lower in Middle and Western China (Ma et al., 2015). Traﬃc emissions, coal and biomass combustion predominantly contributed to the PAH contamination of surface soil in China during the process of urbanization and industrialization (Zhang and Chen, 2017). There was a clear geographical distribution, with concentrations of total 16 PAHs descending in the following order: Northeast > North > East > South > West in China (Zhang and Chen, 2017).