Pollution and Health Risk Assessment of Potentially Toxic Elements in Indoor Dusts from Selected Offices in Adodo-Ota Local Government Area, Ogun State Nigeria

Abstract

Environmental contamination appears to be a significant concern with various possible disastrous aftermaths. The study aimed to investigate the  pollution and health risk assessment of potentially toxic elements (PTEs) in indoor dusts from selected offices in Adodo-Ota local government area (LGA),  Ogun State Nigeria. Ten (10) composite dust samples were strategically collected from various offices into a sample bag, then transported to the  laboratory for analysis. Aqua regia acid digestion was used to digest 1g of the dust sample while Atomic Absorption Spectrometer was used for PTE  estimation. Degree of pollution was determined using geoaccumulation index and enrichment factor. Results from the study showed that the level of Pb  and Zn in 40% and 20% of the samples respectively were higher than the Canada soil/dust guidelines value (CSGV) while Cd, Pb and Zn were the major  pollutants in the indoor dust based on I-geo and EF estimation. This could be linked to wall paints, Zn-coated equipment, roofing sheet from ancient  buildings and dust infiltration from an outdoor environment. Health risk assessment showed that the occupants were free from a significant non-  carcinogenic risk but there is a concern for the value of Pb and Co on children; due to their closeness to the threshold limit. Furthermore, the occupants  have a one in hundred thousand chance of developing cancer on equally prolonged exposure to the dust excluding Pb in children. Therefore, our study  showed that the examined indoor dusts are polluted with some PTEs.