Atmospheric environment problems in Nigeria—An overview

Drivers of anthropogenic air emissions in Nigeria - A review

This study presents a review of sources and atmospheric levels of anthropogenic air emissions in Nigeria with a view to reviewing the existence or otherwise of national coordination aimed at mitigating the continued increase. According to individual researcher's reports, the atmospheric loading of anthropogenic air pollutants is currently on an alarming increase in Nigeria. Greater concerns are premised on the inadequacy existing emission inventories, continuous assessment, political will and development of policy plans for effective mitigation of these pollutants. The identified key drivers of these emissions include gas flaring, petroleum product refining, thermal plants for electricity generation, transportation, manufacturing sector, land use changes, proliferation of small and medium enterprises, medical wastes incineration, municipal waste disposal, domestic cooking, bush burning and agricultural activities such as land cultivation and animal rearing. Having identified the key sources of anthropogenic air emissions and established the rise in their atmospheric levels through aggregation of literature reports, this study calls for a review of energy policy, adoption of best practices in the management air emissions and solid wastes as well as agriculture and land use pattern which appear to be the rallying points of all identified sources of emission. The study concluded that the adoption of cleaner energy policies and initiatives in energy generation and usage as against pursuit of thermal plants and heavy dependence on fossil fuels will assist to ameliorate the atmospheric loadings of these pollutants.

Sources and levels of particulate matter in North African and Sub-Saharan cities: a literature review

In order to assess the significance of PM in ambient air, it is necessary to evaluate their physical and chemical characteristics as well as identify their major emission sources. On a global scale, particulate matter in the atmosphere arises mainly from the combustion process of motorized vehicles, but natural sources are still considered as the major contributors. In Africa, PM emissions differ from those in developed countries; human activities such as biomass burning in households, poor household waste management, and the high number of diesel-powered vehicles are the predominant anthropogenic sources. Natural contributions are also observed. Saharan dust and savanna fires are the most common atmospheric natural sources of particulate matter. The present literature review gives an overview of the status of air quality in African cities and highlights the various sources of particulate matter emissions and local human activities specific to each African region. This could likely serve as a reference to evaluate the current air quality in this region and will be a useful tool in the future to develop pollution mitigation strategies at the source. Recommendations are proposed in the conclusion in order to reduce emissions from their sources, taking into account the low-income African countries.

Urbanization, cities, and health: The challenges to Nigeria - A review

The Nigerian society is rapidly becoming urban as a result of a multitude of push and pull factors. This has generated urban health crises among city dwellers notably the urban poor. A systematic search of published literature in English was conducted between 1960 and 2015. Published peer review journals, abstracts, Gray literature (technical reports, government documents, reports, etc.), inaugural lectures, and internet articles were reviewed. Manual search of reference lists of selected articles were checked for further relevant studies. The review showed that the pace of urbanization is unprecedented with cities such as Lagos having annual urban growth rate of 5.8%. Urbanization in Nigeria is mainly demographically driven without commensurate socioeconomic dividends and benefits to the urban environment. This has created urban health crises of inadequate water safe supply, squalor and shanty settlements, sanitation, solid waste management, double burden of diseases and inefficient, congested, and risky transport system. In conclusion, when managed carefully, urbanization could reduce hardship and human suffering; on the other hand, it could also increase poverty and squalor. Some laws need to be amended to change the status of poor urban settlements. Urban health development requires intersectoral approach with political will and urban renewal program to make our urban societies sustainable that promote healthy living.

Outdoor air particle-bound trace metals in four selected communities in Ibadan, Nigeria

Trace metal concentrations were determined in particulate matter (PM10) in ambient air of four purposively selected residential areas in Ibadan, Nigeria namely Bodija market (BM), Ojo Park (OP), Oluyole Estate (OE) and University of Ibadan (UI). PM10 was determined in the morning (7-10 a.m.) and afternoon (2-5 p.m.) for 12 weeks in the dry season months of January-March using a volumetric sampler following standard procedures and levels compared with WHO guideline limits. Glass-fibre filter papers exposed to the particulate matter were digested using appropriate acid mixtures, and the digest analysed for trace metals including Ni, Cr, Mn, Zn, and Pb using ICPMS method and levels compared with WHO limits. Data was analysed using ANOVA and Pearson correlation test at 5 % level of significance. The highest mean PM10 concentrations 502.3 ± 39.9 μg/m(3) were recorded in the afternoon period at BM, while the lowest concentration 220.6 ± 69.9 μg/m(3) was observed in the morning hours at UI. There was a significant difference between the PM10 levels across the various locations (p < 0.05), and all the levels were higher than WHO limit of 50 μg/m(3). The highest levels of Ni, Zn and Pb were recorded at BM, which also had the highest PM10 burden. The trend in Pb levels across the locations was BM > UI > OP > OE with the highest level 5.70 μg/m(3) in BM nearly fourfolds WHO limits of 1.5 μg/m(3). There was a significant correlation between PM10 and Ni (p < 0.05).Urban communities with increased human activities especially motor traffic recorded both higher levels of PM10 and toxic trace metals. There is need to carry out source apportionment to establish the origin of these trace metals in future studies.

Effects of cement flue dusts from a Nigerian cement plant on air, water and planktonic quality

Effects of cement flue dust from Ewekoro cement Kilns were monitored at some aquatic receptor locations. High levels of total suspended particulates (TSPs) and atmospheric deposition rates (ADRs) were recorded within the factory compared to ancillary locations outside the factory. The TSP and ADR levels which were location dependent were significantly higher (P < 0.05) during the dry periods than in the wet season. Irrespective of seasonal variations, the key elements in the emissions were Ca(2+) and Fe(2+). The concentrations of Zn(2+), Mn(2+) and Pb(+) which were trace elements were significantly higher (P < 0.05) in the deposited than in the airborne particulates. The planktonic flora and fauna of the river systems draining the area were poor with 16 phytoplanktonic and nine zooplanktonic species. Numerically, the phytoplanktons were dominated by diatoms (Bacillariophyta) with Synedra sp. being the most abundant species. The zooplanktonic fauna dominated by rotifers had Lecane curvicornis as a regular occurrence in all the three catchment rivers. The physicochemical parameters assayed were significantly higher (P < 0.05) in the factory effluent discharges than in water samples from each of the catchment rivers. Seasonal variations inclusive, HCO(-)(3), CO(2-)(3), Ca(2+) and Mg(2+) constituted the major ionic component of water samples analysed irrespective of location. Alaguntan River which receives effluents directly from the factory had significantly higher levels (P < 0.05) of the assayed ions than the other two rivers draining the cement factory catchment areas.

Flared Gases and Other Pollutants Associated with Air Quality in Industrial Areas of Nigeria: An Overview

Nigeria, like any other developing nation, is faced with the twin problem of development without destruction. Industrialization, though an important component of development, has had a large share in the despoilation of air quality in the country by the release of high amounts of pollutants into the atmosphere. Petroleum hydrocarbons from refineries, flared gases, dusts, and fumes of metal-smelting and cement works, odorous gases of chemical and allied industries, carbon monoxide and oxides of sulfur and nitrogen of internal combustion engines, the charred particulates and sulfur dioxide emissions of the steel industries etc., all constitute pollutants or co-pollutants of the Nigerian atmosphere. This review article gives an insight into the phenomenal concentrations of some of these pollutants in the Nigerian atmosphere, which point to their unsafe levels and concomitant health risks. It is against this background that there should be continuous but sound monitoring exercise of the Nigerian environment, devoid of the peculiar mix of politics and science, in order to properly audit the quality of air, especially in areas of heavy industrial pollution. Such checks and balances would provide empirical data to assess the various trade-offs of atmospheric pollution in industrial areas of the country such as the Niger Delta region where oil and gas are produced. There should also be enforcement, thereof, of all existing and/or revised standards or regulations such as the compliance limits of the Department of Petroleum Resources (DPR) or the erstwhile Federal Environmental Protection Agency (FEPA).

A survey of trace metals in vegetation, soil and lower animal along some selected major roads in metropolitan city of Lagos

The concentration of trace metals (Cd, Cu, Pb and Zn) in a total of 144 samples of grass, soil and lower animal (earthworm, Lybrodrilus violaceous) were collected and analysed for their metallic content. Levels of cadmium ranged from 0.01-0.07 microg g(-1); 0.01-0.12 microg g(-1) and from trace-0.05 microg g(-1) dry weight for plant, soil and animal samples respectively. Mean concentration of copper ranged 0.10-1.48 microg g(-1); 0.10-2.90 microg g(-1) and 0.01-0.08 microg g(-1) for samples in similar order as above. The levels of Pb varied from 0.01-0.14 microg g(-1); 0.02-0.23 microg g(-1) and from trace-0.07 microg (g-1) while that of Zn ranged from 0.19-1.80 microg g(-1); 0.51-3.35 microg g(-1) and 0.01-0.08 microg g(-1) also in the same order of samples as mentioned above. Levels of metals in soil samples were higher than the background levels with the exception of Zn but lower than European Union (EU) limits. The results generally revealed the presence of metals in plant and animal samples and metal dynamics up the food chain is highly possible. Acceptable recoveries of the spiking experiment validate the experimental protocol.

Lead poisoning of children in Africa, III. Kaduna, Nigeria

This study investigated the prevalence of elevated blood lead (PbB) levels in children 1-6 years old in Kaduna, a medium size city in northern Nigeria. Mean PbB was found to be 10.6 micrograms/dl, and 2% of the children had PbB levels greater than 30 micrograms/dl. Highest average PbB levels were found in children 5 years old and was attributed to the tendency for this age group to play longer in contaminated outdoor environments. The strongest associations were found between PbB and whether the family owned a car or lived in a house on a tarred road. Potential sources of lead in the city as well as household and behavior risk factors likely to result in exposure of children to lead are discussed. This study provides additional data pointing to childhood lead poisoning as being a major public health problem in urban areas of Africa.