title: Spatial distribution, source apportionment and ecological risk assessment of residual organochlorine pesticides (OCPs) in the Himalayas.
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 collected from IHR were analysed for 23 organochlorine pesticides (OCPs). The concentration of ∑OCPs ranged from 0.28 to 2143.96 ng/g (mean 221.54 ng/g) and was mostly dominated by DDTs. The concentration of ∑DDTs ranged from 0.28 to 2126.94 ng/g (mean 216.65 ng/g). Other OCPs such as HCHs, endosulfan and heptachlor, Aldrin and dieldrin were detected in lower concentration in IHR. Their concentrations in soil samples ranged from ND to 2.79 ng/g for HCHs, ND to 2.83 ng/g for endosulfans, NDto 1.46 ng/g for heptachlor, ND to 2.12 ng/g for Aldrin and ND to 1.81 ng/g for dieldrin. Spatial distribution of OCPs suggested prevalence of DDTs and HCHs at Guwahati and Itanagar, respectively. The close relationship between total organic carbon (TOC) and part of OCP compounds (especially α- and γ-HCH) indicated the important role of TOC in accumulation, binding and persistence of OCP in soil. Diagnostic ratio of DDT metabolites and HCH isomers showed DDT contamination is due to recent application of technical DDT and dicofol, and HCH contamination was due to mixture of technical HCH and lindane source. This was further confirmed by principal component analysis. Ecological risk analysis of OCP residues in soil samples concluded the moderate to severe contamination of soil.
authors: 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: Ningombam Linthoingambi
authors: NL
authors: Devi
authors: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China. icyadav.bhu@gmail.com.
authors: Ishwar Chandra
authors: IC
authors: Yadav
authors: Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 221005, India.
authors: Priyankar
authors: P
authors: Raha
authors: State key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 388, Lumo Road, Wuhan, 430074, China.
authors: Qi
authors: Q
authors: Shihua
authors: State key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 388, Lumo Road, Wuhan, 430074, China.
authors: Yang
authors: Y
authors: Dan
mesh_terms: D000531:Altitude; D004463:Ecology; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D007194:India; D010575:Pesticides / Q000032:analysis*; D025341:Principal Component Analysis; D018570:Risk Assessment; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D062206:Spatial Analysis
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D012987:Soil; D012989:Soil Pollutants
keywords: Dibrugarh; Guwahati; Itanagar; Organochlorine pesticides; Tezpur