Polycyclic aromatic hydrocarbons and petroleum products in soil samples of urban areas in Eastern Siberia

Abstract

Introduction. In industrial cities, the problem of environmental pollution by supertoxicants, which include the class of polycyclic aromatic hydrocarbons (PAHs), is especially acute. Since among PAHs there are substances that have a carcinogenic effect, their quantitative identification in environmental objects is an urgent task. Materials and methods. The content of PAHs and petroleum products (PP) in the soil of an industrial city, taken in various functional zones, was studied. Determination of sixteen PAHs was carried out by gas chromatography-mass spectrometry (GC-MS) with optimized sample preparation. It is proposed to determine PAHs by GC-MS using dispersive liquid-liquid microextraction (DLLME). Petroleum products (PP) were determined by the fluorimetric method. Results. Total PAHs content (ΣPAH) varied from 7.50 to 319.11 µg/kg. ΣPAH-carcinogens in the residential and sanitary protection zones was on average 25.1–31.2 times higher than in the background site. PP content levels in urban soils ranged from 3.0 to 62.4 mg/kg. Limitations. The study is limited to the study of the upper layers of soil up to 5 cm. The possibility of PAH migration into groundwater has not been studied. Conclusion. The structure of PAHs was dominated by 4-6-nuclear structures: dibenz(a,h)anthracene, benzo(g,h,i)perylene, fluoranthene, benzo(b)fluoranthene, etc., making up > 87% of the total amount of PAHs. The proportion of these polyarenes in the total ΣPAH in the residential area increases by 1.3 times compared to the background, which indicates the possibility of their technogenic origin. The PAH and PP indicators are characterized by a scatter of data and, as a result, a large influence of the local factor on the formation of soil cover pollution.