Factors governing an integrated solid waste management program A case study at Nuwara-Eliya district secretariat division

Abstract

The suspended particulate matter (SPM) in air is a complex multi-phase mixture of all airborne chemicals. Among the airborne inorganic chemicals, compounds associated with heavy metals have subjected to numerous chemical investigations due their known health effects. Uniqueness of the heavy metals has attributed its use in identifying or tracing the pollutant sources through source apportionment studies and in understanding the distribution of pollutants through computer modeling. In general, airborne metals exist in trace quantities. The suspended particulate matter may contain the metallic species as fine particles or they may have adsorbed onto other particulate matter originated from natural or human activities. Agglomerated heavier particle settles due to gravitation and pose a lesser risk to human health. Finer particles with aerodynamic diameter less than 2.5 urn (PM 2) are believed to posses the biggest health threat through respiration. Central Environmental Authority (CEA) has been involved in air quality monitoring at the Colombo Fort Railway Station. Using their high volume air sampler, particles having aerodynamic diameter less than I 0 ~L1n (PM 10) were collected onto glass fiber filters daily during the period of November 2003 to November 2005 November. They were gravimetrically analyzed by CEA. This study was focused to further investigate randomly selected filters (two filters per month) to differentiate the levels of selected metals during the period. The filters were acid digested to recover the airborne metallic species. Levels of copper (Cu), nickel (Ni), cadmium (Cd), lead (Pb) and manganese (Mn) were analyzed by using atom ic absorption spectrophotometer at the Department of Chemistry, University of Colombo. The average concentrations found during the study were Cu = 0.29 ± 0.25 ng/rri', N i = 0.21 ± 0.1 0 ng/ m ', Pb = 0.59 ± 0.48 ng/rn", Cd = 0.03 ± 0.03 ng/rn ', Mn = 0.43 ± 0.22 ng/rn '. During the study period Pb levels were found to be the highest and Cd levels were found to be the lowest. The maximum airborne levels were 1.24 ng/rn