Seasonal methane emission from municipal solid waste disposal sites in Lagos, Nigeria.

The Municipal Solid Waste (MSW) Sector is a major source of Methane (CH4) emission, a Greenhouse Gas (GHG) that contributes to Climate Change. However, governments of developing countries have not been able to address the challenges posed by this sector due to inadequate funding and technical requirement. The objective of this study was to determine how seasonal variation influences the CH4 gas emission. The First Order Decay (FOD) Tier 1 Model was used to estimate CH4 emission from four Solid Waste Disposal Sites (SWDS) in Lagos namely: Ewu-Elepe (Ewu), Abule-Egba (A/E), Soluos (Sol), and Olushosun (Olu) covering the dry and wet seasons, respectively for the inventory year 2020. A known weight of the wet waste deposited was characterized. The study revealed that the Degradable Organic Carbon (DOC) for the dry season was 12.897 GgC/kgWaste while that of the wet season was 12.547 GgC/kgWaste. But, the methane gas generated during the wet season was 0.331 Gg higher than that of the dry season which was 0.134 Gg for the study period. This is an appreciable quantity of methane that can contribute to the global Climate Change impact if not addressed. Therefore, these waste types should be segregated from other recyclables and processed into compost or energy resource.

Air quality index from charcoal production sites, carboxyheamoglobin and lung function among occupationally exposed charcoal workers in South Western Nigeria.

Charcoal production is often accompanied with gaseous and particulate emission into the atmosphere and occupationally exposed workers could be affected. This cross sectional comparative study was carried out to assess the levels of carbon monoxide (CO), carbon dioxide (CO2), sulphur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter (PM2.5) generated during the phases of charcoal production and their relationship with certain biomarkers among charcoal workers (subjects) and non-charcoal workers (controls) such as carboxyhaemoglobin (COHb), forced expiratory volume in the first second of expiration (FEV1), peak expiratory flow rate (PEFR) and body mass index (BMI) in Igbo-Ora, Oyo State and Alabata, Ogun State, which are two of the major hubs of charcoal production in South Western Nigeria. Four communities in Igbo-Ora and six communities in Alabata were purposively selected and levels of pollutant gases were assessed using appropriate gas meters, PM2.5 was assessed with Thermo Scientific MIE pDR-1500, FEV1 and PEFR were measured with Piko-1 spirometer while COHb was assessed using non-invasive pulse CO-oximeter (Rad 57). Data were statistically analyzed and results were compared with recommended guidelines. The mean FEV1, PEFR, COHb and BMI for subjects and controls were 2.35 ± 0.73 and 2.69 ± 0.56, 253.72 ± 103.45 and 330.02 ± 94.61 (p < 0.01), 13.28 ± 3.91 and 8.50 ± 3.68 (p < 0.01) and 21.97 ± 2.19 and 23.36 ± 3.74 (p < 0.05) respectively. There was a statistically significant difference between actual and expected values of FEV1 (p < 0.01) and PEFR (p < 0.01) among charcoal workers. There existed a positive correlation between CO and COHb while FEV1 and PEFR correlated negatively with PM2.5. The study showed that charcoal workers are exposed to high levels of CO and PM2.5, contributing to lowered respiratory functions for FEV1 and PEFR and high levels of COHb compared to the control group. Routine respiratory and carboxyheamoglobin assessment of persons involved in charcoal production is also recommended.

Compliance with infection control practices by Veterinarians in Nigeria.

BACKGROUND: There is a global increase in morbidity and mortality due to zoonotic diseases hence there is a need to identify possible sources of infections to human population. This study assessed veterinarians' compliance with standard infection control practices (ICPs) for prevention of zoonosis in Nigeria. METHODOLOGY: A cross sectional survey of 320 veterinarians participating in the National Annual Conference of the Nigerian Veterinary Me ic Association was done in November, 2011 Characteristics related to compliance with standard infection control practices were assessed. Chi-square and logistic regression tests were done at 0.05 significant levels. More veterinarians (51.1% and 61.2%) did not comply with appropriate ICPs while carrying out medical procedures of necropsy and assisting in parturition. Those with longer years of practice (OR=0.42,95% CI=0.23-0.75) and with long working hours (OR=0.52, 95% CI=0.28-0.97) were less likely to comply with ICPS. Private practice veterinarians' were less likely than public practitioners to comply (OR=0.67, 95% CI = 0.15-0.69). Also veterinarians who had workplace IC policy were more likely than those without to be compliant with ICPs (OR=3.71, 95% CI = 1.87-7.37). CONCLUSION: Future conferences can be used to advise veterinarians on the importance of implementing appropriate IC measures. Also infection prevention practices laws and policies should be enacted to encourage compliance by veterinarians.

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.

Outdoor respirable particulate matter and the lung function status of residents of selected communities in Ibadan, Nigeria.

BACKGROUND: Ambient air pollution remains a major public health hazard in urban communities. In Nigeria, air quality management especially in the urban centres, is fraught with enormous challenges including limited data. We assessed the outdoor respirable particulate matter (PM10) concentration and the pulmonary function status of residents in four selected communities in Ibadan. METHODS: A cross-sectional study design was employed. Four locations - Ojoo Park (OP = high traffic area), Bodija Market (BM = commercial area), Oluyole Estate (OE = industrial area) and the University of Ibadan (UI = academic community - reference) - were selected based on varying intensities of urban activity. PM10 levels were recorded in the morning and afternoon for 12 weeks between January and March 2008. Lung function status (FEV1) of 140 randomly selected participants was measured. Daily mean of PM10 levels were compared with WHO guideline limits. Data analysis was done using descriptive, χ(2), ANOVA and Spearman-rank correlation tests at 5% level of significance. RESULTS: For all sites, PM10 concentration was generally higher in the afternoon. The highest daily mean PM10 concentration was recorded at BM, followed by OP, OE and UI. These values when compared with WHO guideline limits showed: BM eightfold > OP sevenfold > OE sixfold > UI fivefold (p < .05). Weekly mean PM10 levels and mean FEV1(obs) gave the following order: UI > OE > OP > BM. There was a significant negative correlation between PM10 burden and FEV1(obs) across the study locations (r =-0.371, p < .05). CONCLUSION: Most of the locations with higher particulate burden were observed to have declining lung function status. A longitudinal study to establish more robust associations is advocated.

Polycyclic aromatic hydrocarbon burden in ambient air in selected Niger Delta communities in Nigeria.

The Niger Delta area in Nigeria has major oil producing and refining centers that characterized enormous industrial activities, especially in the petroleum sector. These industrial processes release different kinds of atmospheric pollutants, of which there is paucity of information on their levels and health implications. The objective of this study was to determine the ambient levels of polycyclic aromatic hydrocarbons (PAHs) in communities of a local government area (Eleme) where oil wells, petrochemical installations, a refinery, and a fertilizer complex are located. Respirable particulate matter (PM) in air were collected using Anderson high-volume sampler with PM with aerodynamic diameter > 10 microm (PM10) inlet for collecting filterable, particle-bound PAHs according to standard methods. PAHs were analyzed following standard methods for the 16 World Health Organization (WHO) prioritized components. The results were compared against the levels in another local government area (Ahoada East) with low industrial presence. The average total PAH concentration in Eleme of 9.2 microg/m3 was among the highest in the world; by contrast, the average concentration in Ahoada East was only 0.17 ng/m3. The most prominent PAHs at Eleme were those known to be carcinogenic and included benzo(a)pyrene (1.6 x 10(4) ng/m3 at bubu), benzo(k)fluoranthene (2.4 x 10(4) ng/m3 at Akpajo where a petrochemical is located), pyrene (3.1 x 10(3) ng/m3 at Ogale), and indeno(1,2,3-cd)pyrene (9.1 x 10(3) ng/m3 at Akpajo). Data from this study emphasize the need for a comprehensive source apportionment study and an assessment of the health effects of oil production on local communities of Nigeria where no such information currently exists.

Solid waste management problems in secondary schools in Ibadan, Nigeria.

Inappropriate solid waste management practices in schools in less-developed countries, particularly in major urban communities, constitute one of the major factors leading to declining environmental health conditions. The objective of the authors' descriptive, cross-sectional study was to assess solid waste management problems in selected urban schools in Ibadan, Nigeria. Eight secondary schools with average pupil populations not less than 500 per school were selected randomly. Four hundred questionnaires (50 per school) were administered. In addition, an observational checklist was used to assess the physical environment. Paper and plastics were the most frequently generated wastes. Common methods of solid waste disposal reported were use of dustbins for collection and open burning. Major problems perceived with current refuse disposal methods by the study students were odors, pest infestation, and spillages. Littering and spillages of solid waste were also common features reported. Data suggested inadequate waste management facilities and practices in study schools. The lack of refuse bins may have contributed to waste spillages and the burning practices. Odors may have arisen from both the decay of overstored organic waste rich in moisture and emissions from refuse burning. This scenario poses a community environmental health nuisance and may compromise school environmental quality.