EVALUATION OF THE IMPACT OF CONSTRUCTION STONE MINING IN ABAKALIKI URBAN AREA, EBONYI STATE
Ph.D Thesis by Nwafor, Emmanuel Nnamdi – March 2019
Construction stone mining, the finished product which is granite is used to construct durable, modern structures, create employment and generate revenue. However, the environmental and social impacts of construction stone mining activities are largely seen to be adverse. This is because, construction stones are extracted from excavated areas creating uncovered deep pits which cause accidents to people and livestock; while the wastes from mining activities are disposed in open areas and riverbeds causing soil and surface water pollution. Dust and noise pollution from tipper trucks ferrying stone are causes for concern to villagers as the trucks move even at night, disturbing sleep. The study evaluated the impact of construction stone mining in Abakaliki urban, Ebonyi State, Nigeria. Eight hundred (800) respondents were randomly selected from four communities studied, while air, soil and water samples were collected and analyzed in a standard laboratory. The investigation focused on the impact on socio-economic activities, air, soil, water qualities and physiochemical properties of these natural resources. The locations used for the study were Umuogharu, Ezzagu, Amike Aba and Aguogboriga mining sites in Ezza North, Izzi, Ebonyi and Abakaliki L.G.As respectively. Four gases ; carbon monoxide (CO), nitrogen oxide (NO2), Ammonia (NH3) and Hydrogen sulphide (H2S) were measured at 2 weeks interval up to 12 weeks in the four locations using portable environmental gas monitors, replicated four times at equal distance of 10 metres taken at stable air conditions in all cases. Soil and water samples were collected from each site. The samples were analyzed for relevant physiochemical parameters. The field and laboratory data were subjected to statistical analysis while the means that were found statistically significant were further differentiated using Fisher’s Least Significant Differences (F-LSD). The highest CO air concentration (0.84Mgl-1) was recorded at 4 and 6 weeks and the least, while (0.30 Mgl-10) was recorded at 12 weeks measurement which occurred at Umuogharu, Ezzagu and Aguogboriga. The results showed that there was no significant variation (P<0.05) in NH3 and NO2 while CO and H2S had significant difference (P<0.05) at Ezzagu and Aguogboriga. The results of soil analyses revealed that the physical and chemical parameters like sand, silt, clay, pH, organic carbon, organic matter, percentage nitrogen, available phosphorous, exchangeable acidity and exchangeable cat ion capacity had inverse variation with increase in depth. Water physicochemical properties differed by 50.301.14 to 65.702.76 US/cm, electrical conductivity7.60 0.02 to 8.30 0.69 (Ph), (magnesium). The result of ANOVA indicated that there was highly significant difference (P<0.01) in the level of lead , zinc and Arsenic except cadmium which showed no significant change (P<0.01) in comparison to regulatory requirement. The result of the socio-economic characteristics of the respondents showed that construction stone mining affected the health status and livelihoods of the residents in the communities. Result showed that 62.6%, and 60% suffer from Typhoid, Ringworm, Rashes and diarrhoea due to consumption of water collected from abandoned construction stone mining pits. Similarly, the three surface water bodies sampled were found to be coloured, tasty and unfit for human consumption due to their high turbidity and conductivity. Focus group discussions (FGD) indicated that land despoliation (formation of large gullies), degradation and reduction of available farm lands and associated soil erosion and flooding including reduction in soil fertility are of the most significant adverse impacts of artisanal construction stone mining activities in Abakaliki urban. Against this background, the study recommends environmental restoration, strict environmental and social management planning by operators as well as the enforcement of existing environmental management regulated by relevant Federal and State Ministries and Agencies.