Quantification of Total Suspended Particulate (TSP) and its Elemental Content in Different Micro Environments of a Residential Area in Lagos State, Nigeria

Abstract

The need for comprehensive periodic air quality measurements to assess the extent of airborne particulate matter and trace metals exposure in residential areas in Lagos State in view of the urbanization and different energy cooking source cannot be overemphasized. Total Suspended Particulates (TSP) was collected from July 2016 to April 2017 by gravimetric sampling technique in different indoor-outdoor micro environments of a residential area in Lagos and was analyzed by Atomic Absorption Spectroscopic (AAS) method. High base-line concentrations were obtained with an indoor range of 833.33-1944.45 µgm-3 and outdoor range of 1111.11-1944.45 µgm-3 during the wet season. During the dry season, it ranged from 1111.11-2777.78 µgm-3 in the indoors and 1388.89-2222.22 µgm-3 in the outdoors. Elemental concentrations were subjected to enrichment factor analysis (EF) and principal component analysis (PCA) for source identification. EF analysis was used to assess the relative contributions of natural and anthropogenic metals inputs to the air in the area while, PCA identified road dust, combustion activities and marine as the predominant sources of pollutants emission to the environment. To further elucidate the relationship among pollutants in the sampling sites, correlations analysis, cluster analysis and analysis of variance (ANOVA) were carried out. The results of the correlations analysis and cluster analysis confirmed the results of the EF and PCA. The results of ANOVA showed that, there was no spatial variation in the elemental concentration of most of the metals (P>0.05). Conclusively, results obtained showed that, pollutants concentration in most of the sites were higher than safe limits proposed by regulatory limits.