The impact of biogas and fuelwood use on institutional kitchen air quality in Kampala, Uganda

Air quality management strategies in Africa: A scoping review of the content, context, co-benefits and unintended consequences

One of the major consequences of Africa's rapid urbanisation is the worsening air pollution, especially in urban centres. However, existing societal challenges such as recovery from the COVID-19 pandemic, poverty, intensifying effects of climate change are making prioritisation of addressing air pollution harder. We undertook a scoping review of strategies developed and/or implemented in Africa to provide a repository to stakeholders as a reference that could be applied for various local contexts. The review includes strategies assessed for effectiveness in improving air quality and/or health outcomes, co-benefits of the strategies, potential collaborators, and pitfalls. An international multidisciplinary team convened to develop well-considered research themes and scope from a contextual lens relevant to the African continent. From the initial 18,684 search returns, additional 43 returns through reference chaining, contacting topic experts and policy makers, 65 studies and reports were included for final analysis. Three main strategy categories obtained from the review included technology (75%), policy (20%) and education/behavioural change (5%). Most strategies (83%) predominantly focused on household air pollution compared to outdoor air pollution (17%) yet the latter is increasing due to urbanisation. Mobility strategies were only 6% compared to household energy strategies (88%) yet motorised mobility has rapidly increased over recent decades. A cost effective way to tackle air pollution in African cities given the competing priorities could be by leveraging and adopting implemented strategies, collaborating with actors involved whilst considering local contextual factors. Lessons and best practices from early adopters/implementers can go a long way in identifying opportunities and mitigating potential barriers related to the air quality management strategies hence saving time on trying to "reinvent the wheel" and prevent pitfalls. We suggest collaboration of various stakeholders, such as policy makers, academia, businesses and communities in order to formulate strategies that are suitable and practical to various local contexts.

An appraisal of air quality, thermal comfort, acoustic, and health risk of household kitchens in a developing country

Few studies have documented the air quality, noise, thermal comfort, and health risk assessment of household kitchens related to Sub-Sahara Africa. In this paper, air quality (CO and PM_2.5), thermal comfort (relative humidity (RH) and temperature), noise, and health risk in urban household kitchens with kerosene-fueled stoves were presented. This study was carried out during the dry season (summer) in the Southwestern part of Nigeria. At the breathing zone, PM_2.5 and CO concentrations in the assessed kitchens were measured. In addition, the noise level, RH, and air temperature in the assessed kitchens were also determined. Furthermore, an evaluation of the heat index and health risk of the exposed population to the kerosene-fueled stove kitchens was carried out. During cooking, average CO and PM_2.5 concentrations were 24.77 ± 1.05 ppm and 138.10 ± 2.61 µg/m³, respectively, while the RH was 68.34 ± 0.73%, noise level was 51.14 ± 1.08 dB, and temperature was 29.86 ± 0.23 °C. The CO and noise levels were relatively slightly lower and PM_2.5 was significantly higher than the thresholds recommended by World Health Organisation. In most of the kitchens, the heat index evaluation revealed the possibility of heat exhaustion, heat cramps, and sunstroke with prolonged exposure of the vulnerable group. The air quality index depicted unhealthy (CO exposure) and very unhealthy (PM_2.5 exposure) while the hazard quotient (> 1) implied possible health risk concerning exposure by inhalation. Better design of kitchen with adequate ventilation and improved stoves are suggested.

Improvement of Biogas Quality and Quantity for Small-Scale Biogas-Electricity Generation Application in off-Grid Settings: A Field-Based Study

Small-scale electrical power generation (<100 kW) from biogas plants to provide off-grid electricity is of growing interest. Currently, gas engines are used to meet this demand. Alternatively, more efficient small-scale solid oxide fuel cells (SOFCs) can be used to enhance electricity generation from small-scale biogas plants. Most electricity generators require a constant gas supply and high gas quality in terms of absence of impurities like H2S. Therefore, to efficiently use the biogas from existing decentralized anaerobic digesters for electricity production, higher quality and stable biogas flow must be guaranteed. The installation of a biogas upgrading and buffer system could be considered; however, the cost implication could be high at a small scale as compared to locally available alternatives such as co-digestion and improved digester operation. Therefore, this study initially describes relevant literature related to feedstock pre-treatment, co-digestion and user operational practices of small-scale digesters, which theoretically could lead to major improvements of anaerobic digestion process efficiency. The theoretical preamble is then coupled to the results of a field study, which demonstrated that many locally available resources and user practices constitute frugal innovations with potential to improve biogas quality and digester performance in off-grid settings.

Fine Particulate Matter and Gaseous Compounds in Kitchens and Outdoor Air of Different Dwellings

Passive diffusion tubes for volatile organic compounds (VOCs) and carbonyls and low volume particulate matter (PM_2.5) samplers were used simultaneously in kitchens and outdoor air of four dwellings. PM_2.5 filters were analysed for their carbonaceous content (organic and elemental carbon, OC and EC) by a thermo-optical technique and for polycyclic aromatic hydrocarbon (PAHs) and plasticisers by GC-MS. The morphology and chemical composition of selected PM_2.5 samples were characterised by SEM-EDS. The mean indoor PM_2.5 concentrations ranged from 14 µg m⁻³ to 30 µg m⁻³, while the outdoor levels varied from 18 µg m⁻³ to 30 µg m⁻³. Total carbon represented up to 40% of the PM_2.5 mass. In general, the indoor OC/EC ratios were higher than the outdoor values. Indoor-to-outdoor ratios higher than 1 were observed for VOCs, carbonyls and plasticisers. PAH levels were much higher in the outdoor air. The particulate material was mainly composed of soot aggregates, fly ashes and mineral particles. The hazard quotients associated with VOC inhalation suggested a low probability of non-cancer effects, while the cancer risk was found to be low, but not negligible. Residential exposure to PAHs was dominated by benzo[a]pyrene and has shown to pose an insignificant cancer risk.

Cardiovascular Effects of Indoor Air Pollution from Solid Fuel: Relevance to Sub-Saharan Africa

PURPOSE OF REVIEW

This research aims to summarize evidence on the cardiovascular effects of indoor air pollution (IAP) from solid fuel and identify areas for research and policy for low- and middle-income countries.

RECENT FINDINGS

IAP affects people from low socioeconomic status in Latin America, Asia, and Africa, who depend upon biomass as a fuel for cooking, heating, and lighting. In these settings, IAP disproportionately affects women, children, the elderly, and people with cardiopulmonary disease. The health effects of IAP include acute respiratory infections, chronic obstructive pulmonary disease, pneumoconiosis, cataract and blindness, pulmonary tuberculosis, adverse effects to pregnancy, cancer, and cardiovascular and cerebrovascular disease. New methods for assessing individual IAP exposure, exposing pathways of IAP-related cardiovascular disease, and performing qualitative research focusing on population preferences regarding strategies to reduce IAP exposure have been the most important developments in tackling the burden of IAP. Unfortunately, major disparities exist regarding research into the cardiovascular effects of IAP, with only few studies coming from sub-Saharan Africa, despite this region having the highest proportion of households using solid fuels. Premature cardiovascular deaths and disability can be averted in low-middle income countries by addressing biomass fuel usage by the most disadvantaged settings. While research is needed to uncover the mechanisms involved in cardiovascular outcomes linked to IAP, immediate action is needed to educate the most affected populations on IAP health hazards and to reduce their exposure to this environmental risk through promoting improved housing and better ventilation, as well as increasing access to affordable clean cooking energy.

Women and girls in resource poor countries experience much greater exposure to household air pollutants than men: Results from Uganda and Ethiopia

Household Air Pollution (HAP) from burning biomass fuels is a major cause of mortality and morbidity in low-income settings worldwide. Little is known about the differences in objective personal HAP exposure by age and gender. We measured personal exposure to HAP across six groups defined by age and gender (young children, young males, young females, adult males, adult females, and elderly) in rural households in two sub-Saharan African countries. Data on 24-hour personal exposure to HAP were collected from 215 participants from 85 households in Uganda and Ethiopia. HAP exposure was assessed by measuring carbon monoxide (CO) and/or fine particulate matter (PM_2.5) concentrations using five types of devices. 24 h PM_2.5 personal exposure was highest among adult females with Geometric Mean (GM) and Geometric Standard Deviation (GSD) concentrations of 205 μg/m³ (1.67) in Ethiopia; 177 μg/m³ (1.61 GSD) in Uganda. The lowest PM_2.5 exposures were recorded among young males GM (GSD) 30.2 μg/m³ (1.89) in Ethiopia; 26.3 μg/m³ (1.48) in Uganda. Young females had exposures about two-thirds of the adult female group. Adult males, young children and the elderly experienced lower exposures reflecting their limited involvement in cooking. There was a similar pattern of exposure by age and gender in both countries and when assessed by CO measurement. There are substantial differences in exposure to HAP depending on age and gender in sub-Saharan Africa rural households reflecting differences in household cooking activity and time spent indoors. Future work should consider these differences when implementing exposure reduction interventions. There was a strong agreement between optical and gravimetric devices measurements although optical devices tended to overestimate exposure. There is need to calibrate optical devices against a gravimetric standard prior to quantifying exposure.