Impact of differential occupational LPG exposure on cardiopulmonary indices, liver function, and oxidative stress in Northwestern city of Nigeria.

Exposure to hydrocarbon products has been associated with numerous health risks and toxicities. Outdoor or indoor occupational exposure to highly volatile and lipid-soluble hydrocarbons has been linked to impairment of respiratory, cardiovascular, and liver functions. This study is aimed at determining the potential impact of occupational exposure to liquefied petroleum gas (LPG) in varying work environments. Respiratory symptoms, oxidative stress, cardio-pulmonary, and liver function parameters were assessed among LPG workers in the Kano metropolis, Nigeria. Study subjects were recruited from LPG filling stations and street LPG retail shops. Results of the study showed that the forced vital capacity (FVC) of LPG station workers was significantly lower (2.81 L/min; H = 22.473, p < 0.001) relative to the values recorded among LPG retail shop workers and the controls (3.54 L/min and 4.24 L/min respectively). A similar reduction was seen in the forced expiratory volume in the first second (FEV1) and the forced expiratory flow in 25-75 % of forced vital capacity (FEF25-75) obtained from the filling station workers (H = 32.722, p < 0.001 & H = 15.655, p <0.001 respectively). Furthermore, exposure to non-combusted LPG increased systolic blood pressure, mean arterial pressure, and serum liver enzymes. Findings from this study revealed that despite the high amount of coarse particulate matter in LPG retail shops, the filling station workers are more susceptible to the impairment of lung function possibly due to the high quantity of total volatile organic compounds (TVOCs) in the filling station environment.

Adaptation measures under the impacts of climate and land-use/land-cover changes using HSPF model simulation: Application to Gongola river basin, Nigeria.

Recently, there is an upsurge in flood emergencies in Nigeria, in which their frequencies and impacts are expected to exacerbate in the future due to land-use/land cover (LULC) and climate change stressors. The separate and combined forces of these stressors on the Gongola river basin is feebly understood and the probable future impacts are not clear. Accordingly, this study uses a process-based watershed modelling approach - the Hydrological Simulation Program FORTRAN (HSPF) (i) to understand the basin's current and future hydrological fluxes and (ii) to quantify the effectiveness of five management options as adaptation measures for the impacts of the stressors. The ensemble means of the three models derived from the Coupled Model Intercomparison Project Phase 5 (CMIP5) are employed for generating future climate scenarios, considering three distinct radiative forcing peculiar to the study area. Also, the historical and future LULC (developed from the hybrid of Cellular Automata and Markov Chain model) are used to produce the LULC scenarios for the basin. The effective calibration, uncertainty and sensitivity analyses are used for optimising the parameters of the model and the validated result implies a plausible model with efficiency of up to 75 %. Consequently, the results of individual impacts of the stressors yield amplification of the peak flows, with more profound impacts from climate stressor than the LULC. Therefore, the climate impact may trigger a marked peak discharge that is 48 % higher as compared to the historical peak flows which are equivalent to 10,000-year flood event. Whilst the combine impacts may further amplify this value by 27 % depending on the scenario. The proposed management interventions such as planned reforestation and reservoir at Dindima should attenuate the disastrous peak discharges by almost 36 %. Furthermore, the land management option should promote the carbon-sequestering project of the Paris agreement ratified by Nigeria. While the reservoir would serve secondary functions of energy production; employment opportunities, aside other social aspects. These measures are therefore expected to mitigate feasibly the negative impacts anticipated from the stressors and the approach can be employed in other river basins in Africa confronted with similar challenges.

Emission factors of some common grass species in West Africa.

Frequent burnings occurring in the grasslands of the West African region during the dry seasons largely contribute to emissions of trace gases and particulates being released into the ambient environment, which has significantly impacted both regional and global climate patterns. Burning potentials of forty different grassland biomes were examined by determining their Net Heating Value (NHV) and Total Organic Carbon (TOC). Simulations of the field operations which involve open burning were performed in the laboratory using a fabricated combustion chamber for the determination of emission factors. Particulates were collected using Whatman quartz fibre filters and analyzed gravimetrically. Emissions of gaseous pollutants from open burning of these common grass species were measured with portable devices. The values of the NHV and TOC of the grass species ranged from 15,022.19 to 18,181.84 kJ/kg and 21.14 to 55.62%, respectively. The average Emission Factors (EFs) obtained for carbon dioxide (CO2), carbon monoxide (CO), sulphur dioxide (SO2), nitrogen dioxide (NO2), volatile organic compounds (VOC), and PM2.5 are 1465.55 g/kg, 40.99 g/kg, 0.39 g/kg, 0.02 g/kg, 7.78 g/kg, and 6.00 g/kg, respectively. The study has shown that Digitaria nuda, Digitaria eriantha, Panicum subalbidum, Paspalum polystratchyum, and Perotis indica have the highest emission factors for CO2, CO, SO2, NO2, VOC, and PM2.5, respectively. The result obtained would help in the quantification of the global warming forcing on the climate in the West African region from grassland burnings. The results will potentially serve as additional information for emission inventories and basis for the formulation of mitigation strategies.