SPATIAL DISTRIBUTION AND HEALTH RISK ASSESSMENT OF HEAVY METALS IN URBAN PARKS AND GARDENS SOILS IN LAGOS STATE, NIGERIA

Abstract

Distribution and health risk assessment of heavy metals in urban parks and gardens Gani Fawehinmi Park, Ojota, (GFP), Oshodi Heritage Park Oshodi (OHP), Ikorodu/Ipado Garden (IIG), MKO Abiola Gardens, Ojota (MKO), and MOE Garden, Alausa (MOE) soils in Lagos Metropolis, Nigeria were examined using Index of Geo-accumulation (I_geo), Potential Ecological Risk Index (RI) and health risk model. Urban parks and gardens soils were substantially polluted by Cu and Pb due closeness to highways where heavy metals emitted from motor vehicles are deposited.  Geoaccumulation index (Igeo) values for Pb were 10.616, 10.060, 9.027, 8.862 and 8.665 for GFP, OHP, IIG, MKO and MOE respectively. RI values for all the sites showed high pollution as they were all above 200. Health risk assessment revealed that children who visit the urban parks and garden in Lagos State are more exposed to cancer risk from Pb especially through ingestion. Results from this study provided valuable information on the pollution levels of urban parks in Lagos, Nigeria as a result of traffic related emissions and calls for proper monitoring of anthropogenic activities in the metropolis and reduce the human health impacts. The planting of hedge plants and erection of low walls could serve as shield against traffic pollution for the roadside parks