Assessment of Environmental Impact in Soil Samples from Selected Market Dumpsites in Ikorodu Metropolis, Lagos State, South Western Nigeria

The study assessed the environmental impact of selected market waste dumpsites in soil samples in Ikorodu metropolis in order to determine the effect of the level of health hazard on the residents of Ikorodu community. The measurement was carried out using a Gamma ray Spectrometer NaI (TI)detector coupled to a Multichannel analyser for spectral analysis. Results revealed that the activity concentration of K-40 in soil samples ranged from 14.84 +/- 1.07 BqKg(-1) to 82.01 +/- 5.54 BqKg(-1) with the highest found in Adamo Market and the lowest was found in Benson market. The activity concentration of U-238 ranged from 0.029 +/- 0.05 BqKg(-1) to 7.65 +/- 0.9 BqKg(-1) with the highest found in Agunfoye Market and the lowest found in Benson Market. The activity concentrations of Th-232 ranged from 1.68 +/- 0.14 BqKg(-1) to 3.93 +/- 0.28 BqKg(-1), the highest concentration was found in Agunfoye Market and the lowest was found in Ayangburen Market. The values were within the safety limit recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) with mean value of 13.5 - 69.8 BqKg(-1). The Absorbed Dose Rate, Outdoor, Annual Effective Dose Rate, and the Internal and External Hazard Index was also calculated from the activity concentrations which shows that the absorbed dose rates due to gamma rays at 1m above the ground in the study area were within the range of 1.99 nGyh(-1) to 7.06 nGyh(-1) with an average of 4.08 nGyh(-1) which is lower than the UNSCEAR average value of 59 nGyh(-1). The annual effective doses are within the range of 0.00 to 0.01 mSvy(-1) with an average value of 0.01 mSvy(-1) which were lower when compared with the UNSCEAR value of 0.5 mSvy(-1) and 0.07 mSvy(-1) respectively. The External Hazard Index in the soil samples ranges from 0.01 to 0.04 with an average value of 0.02 and the Internal Hazard Index ranges from 0.01 to 0.06 with an average value of 0.03 both of which were below the permissible limit respectively, and less than 1. However, the values of the radiological parameters were below the UNSCEAR recommended international limits of 370Bq/kg and within the tolerance level indicating minimal radiological health burden on the people living in the study areas.