title: Mass burden and estimated flux of heavy metals in Pakistan coast: sedimentary pollution and eco-toxicological concerns.
abstract: Heavy-metal contamination in coastal areas poses a serious threat to aquatic life and public health due to their high toxicity and bio-accumulation potential. In the present study, levels of different heavy metals (Cu, Cd, Cr, Ni, Co, Pb, Zn, and Mn), their spatial distribution, geochemical status, and enrichment indices (Cu, Cd, Cr, Ni, Co, Pb, Zn) were investigated in the sediment samples from 18 coastal sites of Pakistan. The analyses of coastal sediments indicated the presence of heavy metals in order such as Cr > Zn > Cu > Pb > Ni > Mn > Co > Cd. Geo-accumulation index (I geo), enrichment factor (EF), and contamination factor (CF) showed diverse range in heavy-metal enrichment site by site. Pollution load index (PLI) has shown that average pollution load along the entire coastal belt was not significant. Based on the mean effect range medium quotient, coastal sediments of Pakistan had 21% probability of toxicity. The estimated sedimentary load of selected heavy metals was recorded in the range of 0.3-44.7 g/cm(2)/year, while the depositional flux was in the range of 0.07-43.5 t/year. Heavy-metal inventories of 9.8 × 10(2)-3.8 × 10(5) t were estimated in the coastal sediments of Pakistan. The enrichment and contamination factors (EF and CF) suggested significant influence of anthropogenic and industrial activities along the coastal belt of Pakistan.
authors.affiliation: Environmental Biology and Ecotoxicology Laboratory, Faculty of Biological Sciences, Department of Environmental Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Usman
authors.initials: U
authors.lastname: Ali
authors.forename: Riffat Naseem
authors.initials: RN
authors.lastname: Malik
authors.forename: Jabir Hussain
authors.initials: JH
authors.lastname: Syed
authors.forename: Ch Tahir
authors.initials: ChT
authors.lastname: Mehmood
authors.forename: Laura
authors.initials: L
authors.lastname: Sánchez-García
authors.forename: Azeem
authors.initials: A
authors.lastname: Khalid
authors.forename: Muhammad Jamshed Iqbal
authors.initials: MJ
authors.lastname: Chaudhry
mesh_terms: D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000009:adverse effects* / Q000032:analysis; D019015:Geologic Sediments / Q000737:chemistry*; D006801:Humans; D019216:Metals, Heavy / Q000737:chemistry*; D010154:Pakistan; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical