title: Microorganisms and heavy metals associated with atmospheric deposition in a congested urban environment of a developing country: Sri Lanka.
abstract: The presence of bacteria and heavy metals in atmospheric deposition were investigated in Kandy, Sri Lanka, which is a typical city in the developing world with significant traffic congestion. Atmospheric deposition samples were analyzed for Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb which are heavy metals common to urban environments. Al and Fe were found in high concentrations due to the presence of natural sources, but may also be re-suspended by vehicular traffic. Relatively high concentrations of toxic metals such as Cr and Pb in dissolved form were also found. High Zn loads can be attributed to vehicular emissions and the wide use of Zn coated roofing materials. The metal loads in wet deposition showed higher concentrations compared to dry deposition. The metal concentrations among the different sampling sites significantly differ from each other depending on the traffic conditions. Industrial activities are not significant in Kandy City. Consequently, the traffic exerts high influence on heavy metal loadings. As part of the bacterial investigations, nine species of culturable bacteria, namely; Sphingomonas sp., Pseudomonas aeruginosa, Pseudomonas monteilii, Klebsiella pneumonia, Ochrobactrum intermedium, Leclercia adecarboxylata, Exiguobacterium sp., Bacillus pumilus and Kocuria kristinae, which are opportunistic pathogens, were identified. This is the first time Pseudomonas monteilii and Ochrobactrum intermedium has been reported from a country in Asia. The culturable fraction constituted ~0.01 to 10%. Pigmented bacteria and endospore forming bacteria were copious in the atmospheric depositions due to their capability to withstand harsh environmental conditions. The presence of pathogenic bacteria and heavy metals creates potential human and ecosystem health risk.
authors.affiliation: Environmental Chemodynamics Project, National Institute of Fundamental Studies, Kandy, Sri Lanka.
authors.forename: Lakshika
authors.initials: L
authors.lastname: Weerasundara
authors.affiliation: Cell Biology, National Institute of Fundamental Studies, Kandy, Sri Lanka.
authors.forename: R W K
authors.initials: RWK
authors.lastname: Amarasekara
authors.affiliation: Cell Biology, National Institute of Fundamental Studies, Kandy, Sri Lanka. Electronic address: nayomam@yahoo.com.
authors.forename: D N
authors.initials: DN
authors.lastname: Magana-Arachchi
authors.affiliation: Science and Engineering Faculty, Queensland University of Technology (QUT), Brisbane, Australia.
authors.forename: Abdul M
authors.initials: AM
authors.lastname: Ziyath
authors.affiliation: Department of Chemical and Process Engineering, Faculty of Engineering, University of Peradeniya, Sri Lanka.
authors.forename: D G G P
authors.initials: DGGP
authors.lastname: Karunaratne
authors.affiliation: Science and Engineering Faculty, Queensland University of Technology (QUT), Brisbane, Australia.
authors.forename: Ashantha
authors.initials: A
authors.lastname: Goonetilleke
authors.affiliation: Environmental Chemodynamics Project, National Institute of Fundamental Studies, Kandy, Sri Lanka. Electronic address: meththikavithanage@gmail.com.
authors.forename: Meththika
authors.initials: M
authors.lastname: Vithanage
mesh_terms: D000391:Air Microbiology; D000393:Air Pollutants / Q000032:analysis*; D001419:Bacteria / Q000302:isolation & purification; D002947:Cities; D003906:Developing Countries; D004784:Environmental Monitoring; D006801:Humans; D019216:Metals, Heavy / Q000032:analysis*; D013188:Sri Lanka
chemical_list: D000393:Air Pollutants; D019216:Metals, Heavy
keywords: Atmospheric pollution; Bacteria; Heavy metals; Opportunistic pathogens; Sri Lanka; Wet and dry deposition