Abstract View
Health Risk Assessment and Chemical Characterization of Settling Dust Exposed to Children: A Case Study of Primary School at Karachi, Pakistan
SAIYADA MASOOD, Sumayya Saied, Farheen Anwar, Azhar Siddique, Kamran Khan, Haider Khwaja, Jinnah University for Women
Abstract Number: 441
Working Group: Health-Related Aerosols
Abstract
Primary school children are at high risk of pollution due to their frequent exposure with contaminants through various means and unawareness. Dust particles are heavier atmospheric aerosols of the range ≥ 100µm and retain in planetary boundary layer (PBL) and eventually settled on surface(s). The composition of particle depends on the origin of nucleation and track on which chemical species adhere and become the part before deposition. A preliminary study is designed to assess the dust particles with reference to the exposure of children in primary school at Karachi city. Indoor (classroom) and outdoor (playground) samples were collected for comparative study. Sample extracts were assessed for pH (6.15), anions (mg/kg) namely with average values F- (426±136), Cl- (13458±8161), Br- (17.3±9.4), SO42- (9331±3318), C2O42- (79.7±58.2) through Ion chromatography and metal profile was obtained through XRF. Most prominent chemical species measured with distinctly high distribution in indoor and outdoor samples were the metal components (mg/kg) like Mo (6.5±1.6), Zr (55.1±3.5), Sr (219±3.97), Rb(19.3±1.75), Pb (117.2±6.55), Zn (799±17.9), Cu (190±13.8), Fe (12324±128), Mn (113±35.9), Ti (2134±75.9), Ca (126241±613) and K (11227±280), other metals were observed < LOD. Ca concentration was high due to the use of chalks in classrooms. Prominent concentration of sulfur in mg/kg (5988±482) was observed in indoor dust. Outdoor dust is associated with road dust. High levels of metals, like Cu, Pb and Zn are linked to high motor vehicle traffic in Karachi city. Health Risk was assessed by evaluating Average Daily Dose ADD(ingestion), ADD(inhalation) and ADD(dermal) for noncarcinogenic and carcinogenic metals vs reference values.