No abstract

No abstract

Commercial activities in urban cities in the world have contributed to the development of the society and at the same time impact negatively on the environment. This study investigated the influence of some commercial centres namely: Akpanadem Market, Uyo Plaza, Itam Market and Itam Abattoir in Uyo Metropolis to ascertain their air quality based on the activities carried out at each location. The levels of NO2, SO2, H2S, CO, Cl2, NH3, HCN, CH2O, TVOCs, PM2.5, and PM10 were monitored at the studied locations using standard instruments. Results obtained revealed that the mean concentrations of all the air pollutants determined except SO2 were above their recommended limits by Federal Environmental and Protection Agency (FEPA). It was also observed that, activities at Itam abattoir released the highest levels of these air pollutants. The dumping of organic wastes in markets, cigarette smoking, emissions from generators and vehicles, use of condemned tyres and petroleum products were the major sources of these pollutants at the studied locations. The multivariate analysis revealed the anthropogenic source as the major route for the release of these pollutants into the air environment. Air quality index analysis showed that if human beings are exposed to the levels of these air pollutants at all the locations for a long time, they can affect both the sensitive to non-sensitive groups adversely. The results of this study should be used for the proper planning and management of these commercial centres by the concerned agencies.

TAN), Total Oxidation Products (TOP) and the infra-red spectral changes of the decomposition products at various temperatures ranging from 100°C to as high as 380°C. The results indicated that the mineral oil showed a higher aging characteristics in both the thermal and thermo-oxidative decomposition than its synthetic multigrade counterpart. The infra-red analysis revealed that the physicochemical changes associated with aging of the oil samples at high temperature were mainly due to the breakdown of additives and hydrocarbon matrix at the onset of aging into monomeric fragments of peroxides

Road transport is associated with the elevation of trace metals in the adjoining soils and vegetables and rate of metal accumulation on these media is directly related to the traffic density. This research investigated the association between traffic density, metal accumulation, pollution status, and human health problems in adjoining soils and vegetables within the southern Region of Nigeria. Top soils and vegetables (Vernonia amygdalina and Jatropha tanjorensis) were obtained from roadsides along roads with high traffic density namely: Abak, Aka, Ikot Ekpene, Nwanaiba, and Oron. Top soils and vegetables were also obtained from roadside along a road with low traffic density (Ekpri Nsukara) and used as the Controls. These samples and their Controls obtained within Uyo Metropolis using standard procedures were subjected to acceptable analytical treatments and determined the levels of Cd, Cu, Fe, Ni, Pb, and Zn using Spectroscopic methods. Results obtained revealed that, the mean concentrations of these metals in studied soils and vegetables were within their acceptable limits by FAO/WHO. However, higher mean concentrations of these metals were obtained in soils and vegetables from roads with high traffic density than in the Control. Higher mean levels of all the metals were recorded in J. tanjorensis than in V. amygdalina. The contamination factor of the metals in soil varied between moderate and very high contamination classes. The ecological risk factor of the metals ranged from low to the very high risk classes for the respective metals. Potential ecological risk factor revealed very high risks for the metals determined. Higher transfer factors were obtained for J. tanjorensis than V. amygdalina, though below one. Principal component analysis identified one key factor for the accumulation of these metals in the studied soils and vegetables. The metals were within their oral reference doses but, Cd and Pb were above their recommended daily intake limit. The consumption of V. amygdalina and J. tanjorensis exposed the consumers to risks associated with high Cd and Pb, respectively though; the consumers of J. tanjorensis were generally more susceptible to more non-cancer risks. The potential cancer risks associated with the trace metals via the consumption of the studied vegetables varied between the low and moderate cancer risk classes. However, the target cancer risk values obtained for the metals were higher than the threshold risk limit for ILCR < 1 × 10−4 .by USEPA. The total cancer risk revealed that, Cd and Cu were the major carcinogens in the studied vegetables while, the consumers of V. amygdalina have a higher risk of developing cancer than J. Tanjorensis. The study has shown the relationship between road transport and traffic density on the accumulation of metals in soil and vegetables. Health risks associated with the exposure to metals via the consumption of the studied vegetables has also been exposed.