title: Characterization and source identification of airborne particulate loadings at receptor site-classes of Lagos Mega-City, Nigeria.
abstract: Size segregated suspended particulate matter (PM2.5 and PM2.5-10) were collected using Gent low-volume air sampler at four different receptor site-classes in Lagos Mega City, Nigeria. The particulate mass loading was quantified and the concentration was analyzed to examine the pattern and variation from one receptor site-class to another. The PM2.5/PM10 ratio varied among the site-classes with the residential and marine sites having the least and highest ratio of 0.31 +/- 0.13 and 0.49 +/- 0.17 respectively. Particulate loading was higher on weekdays than on weekends (by a factor of about 1.5) in all but the marine site-class.The mean PM2.5/PM10 ratio is 0.41 +/- 0.15, which suggests that traffic emission is not the principal source of the Particulate Matter (PM). The INAA assay of the particulates detected ten elements: As, Br, Ce, K, La, Mo, Na, Sb, Sm and Zn. Except for Br, Mo and Sb, the detected elements were more pronounced in the coarse-fractioned filter Principal Component Factor Analysis (PCFA) of the detected elements identified some common sources (traffic-related, traffic emission, sea-salt and industrial emission) for both PM fractions at the four receptor site-classes.
authors.affiliation: Environmental Research Laboratory (ERL), Department of Physics, Obafemi Awolowo University, Ile-Ife, Nigeria. oowoade@oauife.edu.ng
authors.forename: Oyediran K
authors.initials: OK
authors.lastname: Owoade
authors.forename: Olusegun G
authors.initials: OG
authors.lastname: Fawole
authors.forename: Felix S
authors.initials: FS
authors.lastname: Olise
authors.forename: Lasun T
authors.initials: LT
authors.lastname: Ogundele
authors.forename: Hezekiah B
authors.initials: HB
authors.lastname: Olaniyi
authors.forename: Marta S
authors.initials: MS
authors.lastname: Almeida
authors.forename: Manh-Dung
authors.initials: MD
authors.lastname: Ho
authors.forename: Philip K
authors.initials: PK
authors.lastname: Hopke
mesh_terms: D000397:Air Pollution / Q000032:analysis* / Q000706:statistics & numerical data*; D002947:Cities; D004602:Elements; D009549:Nigeria; D052638:Particulate Matter / Q000032:analysis*; D025341:Principal Component Analysis
chemical_list: D004602:Elements; D052638:Particulate Matter