title: Environmental carcinogenic polycyclic aromatic hydrocarbons in soil from Himalayas, India: Implications for spatial distribution, sources apportionment and risk assessment.
abstract: The Indian Himalayan Region (IHR) is one of the important mountain ecosystems among the global mountain system which support wide variety of flora, fauna, human communities and cultural diversities. Surface soil samples (n = 69) collected from IHR were analysed for 16 priority polycyclic aromatic hydrocarbons (PAH) listed by USEPA. The ∑16PAH concentration in surface soil ranged from 15.3 to 4762 ngg(-1) (mean 458 ngg(-1)). The sum total of low molecular weight PAH (∑LMW-PAHs) (mean 74.0 ngg(-1)) were relatively lower than the high molecular weight PAH (∑HMW-PAHs) (mean 384 ngg(-1)). The concentration of eight carcinogenic PAHs (BaA, CHR, BbF, BkF, BaP, DahA, IcdP, BghiP) were detected high in mountain soil from IHR and ranged from 0.73 to 2729 ngg(-1) (mean 272 ngg(-1)). Based on spatial distribution map, high concentration of HMW- and LMW-PAHs were detected at GS1 site in Guwahati (615 and 4071 ngg(-1)), and lowest concentration of HMW-PAHs were found at IS6 in Itanagar (5.80 ngg(-1)) and LMW-PAHs at DS2 (17.3 ngg(-1)) in Dibrugarh. Total organic carbon (TOC) in mountain soil was poorly connected with ∑PAHs (r(2) = 0.072) and Car-PAHs (r(2) = 0.048), suggesting the little role of TOC in adsorption of PAHs. Isomeric ratio of PAHs showed the source of PAH contamination in IHR is mixed of petrogenic and pyrogenic origin and was affirmed by PAHs composition profile. These source apportionment results were further confirmed by principal component analysis (PCA). Eco-toxicological analysis showed the calculated TEQ for most carcinogenic PAH were 2-4 times more than the Dutch allowed limit, while TEQ of BaP was 25 times high, suggesting increasing trend of carcinogenicity of surface soil.
authors.affiliation: Centre for Environmental Sciences, Central University of South Bihar, BIT Campus, Patna, 800014 Bihar, India; Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 221005, India.
authors.forename: Ningombam Linthoingambi
authors.initials: NL
authors.lastname: Devi
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China. Electronic address: icyadav.bhu@gmail.com.
authors.forename: Ishwar Chandra
authors.initials: IC
authors.lastname: Yadav
authors.affiliation: State Key Laboratory of Bio-geology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 388, Lumo Road, Wuhan, 430074, PR China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Shihua
authors.affiliation: State Key Laboratory of Bio-geology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 388, Lumo Road, Wuhan, 430074, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Dan
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China.
authors.forename: Gan
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 221005, India.
authors.forename: Priyankar
authors.initials: P
authors.lastname: Raha
mesh_terms: D002273:Carcinogens / Q000032:analysis* / Q000633:toxicity; D004784:Environmental Monitoring; D006801:Humans; D007194:India; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000633:toxicity; D018570:Risk Assessment; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000633:toxicity; D062206:Spatial Analysis
chemical_list: D002273:Carcinogens; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants
keywords: Carcinogenic; Combustion; Himalayas; Indian Himalayan region; Isomeric ratio; Polycyclic aromatic hydrocarbon