title: Toxic Metal Pollution in Pakistan and Its Possible Risks to Public Health.
abstract: Environmental pollution has increased many folds in recent years and in some places has reached levels that are toxic to living things. Among pollutant types, toxic heavy metals and metalloids are among the chemicals that pose the highest threat to biological systems (Jjemba 2004). Unlike organic pollutants, which are biodegradable, heavy metals are not degraded into less hazardous end products (Gupta et al. 2001). Low concentrations of some heavy metals are essential for life, but some of them like Hg, As, Pb and Cd are biologically non-essential and very toxic to living organisms. Even the essential metals may become toxic if they are present at a concentration above the permissible level (Puttaiah and Kiran 2008). For example, exposure to Zn and Fe oxides produce gastric disorder and vomiting, irritation of the skin and mucous membranes. Intake of Ni, Cr, Pb, Cd and Cu causes heart problems, leukemia and cancer, while Co and Mg can cause anemia and hypertension (Drasch et al. 2006). Similarly, various studies indicated that overexposure to heavy metals in air can cause cardiovascular disorders (Miller et al. 2007; Schwartz 2001), asthma (Wiwatanadate and Liwsrisakun 2011), bronchitis/emphysema (Pope 2000), and other respiratory diseases (Dominici et al. 2006).
authors.affiliation: Department of Botany, Kohat University of Sciences and Technology (KUST), 26000, Kohat, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Shakirullah Khan
authors.initials: SK
authors.lastname: Shakir
authors.affiliation: Department of Botany, Kohat University of Sciences and Technology (KUST), 26000, Kohat, Khyber Pakhtunkhwa, Pakistan. azizswabi@hotmail.com.
authors.forename: Azizullah
authors.initials: A
authors.lastname: Azizullah
authors.affiliation: Department of Botany, Kohat University of Sciences and Technology (KUST), 26000, Kohat, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Waheed
authors.initials: W
authors.lastname: Murad
authors.affiliation: Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, 26000, Pakistan.
authors.forename: Muhammad K
authors.initials: MK
authors.lastname: Daud
authors.affiliation: Department of Botany, Kohat University of Sciences and Technology (KUST), 26000, Kohat, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Farhat
authors.initials: F
authors.lastname: Nabeela
authors.affiliation: Department of Microbiology, Kohat University of Science and Technology, Kohat, 26000, Pakistan.
authors.forename: Hazir
authors.initials: H
authors.lastname: Rahman
authors.affiliation: Department of Botany, Kohat University of Sciences and Technology (KUST), 26000, Kohat, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Shafiq
authors.initials: S
authors.lastname: Ur Rehman
authors.affiliation: , Neue Straße 9, 91096, Möhrendorf, Germany.
authors.forename: Donat-Peter
authors.initials: DP
authors.lastname: Häder
mesh_terms: D004787:Environmental Pollution; D006801:Humans; D019216:Metals, Heavy / Q000633:toxicity*; D010154:Pakistan; D011634:Public Health; D018570:Risk Assessment
chemical_list: D019216:Metals, Heavy
keywords: Air pollution; Arsenic; Cadmium; Chromium; Cobalt; Copper; Hazard index; Hazard quotient; Health risk; Heavy metals; Industrial effluents; Iron; Lead; Manganese; Mercury; Municipal wastes; Nickel; Pakistan; Permissible limits; Reference dose; Risk assessment; Soil pollution; Vehicular emissions; Water pollution; Zinc