• Energy Research

Abstract This study provides valuable insight into impacts of COVID-19 emergency public health “lockdown” measures upon traffic flow, active travel and gaseous pollutant concentrations (NO, NO2, and O3) in Oxford city centre during 2020. Comparisons of traffic counts indicated pronounced changes in traffic volume associated with national lockdown periods. Car volume reduced by 77.5% (statistically significant) during the first national lockdown, with lesser changes in goods vehicles and public transport (bus) activity during the second lockdown. Cycle flow reduced substantively during the first lockdown only. These changes resulted in a reduction in nitric oxide (NO) and nitrogen dioxide (NO2) concentrations of 75.1% and 47.4%, respectively at roadside, and 71.8% and 34.1% at urban background during the first lockdown period. In contrast ozone (O3) concentrations increased at the urban background site by 22.3% during the first lockdown period, with no significant changes in gaseous concentrations during the second lockdown at either roadside or urban background location. The diurnal pattern of peak mean NO and NO2 concentrations reduced in magnitude and was shifted approximately 2 hours earlier in the morning and 2 hours later in the evening (roadside) and 3 hours earlier in the morning and 3 hours later in the evening (urban background). Our findings provide an example of how gaseous air quality in urban environments could respond to future urban traffic restrictions, suggesting benefits from reductions in peak and daily NO2 exposures may be offset by health harms arising from increases in ground level O3 concentrations in the summer months.

Household air pollution (HAP) from cooking on biomass fuel presents significant health, environmental and socioeconomic consequences worldwide. However, there is a lack of understanding of the factors influencing cooking behaviours that affect HAP exposure in Rwanda (e.g., cooking location, removing children from the cooking area). Sixteen qualitative in-depth interviews were undertaken with women living in an underprivileged neighbourhood in Kigali, Rwanda. Deductive thematic analysis was carried out using the Behaviour Change Wheel (Capability—ability to engage with chosen activity, Opportunity—factors which are beyond the individual’s control and Motivation—brain processes which direct behaviour: COM-B) to determine the thoughts and perceptions around cooking location and removing children from the cooking area. Facilitators and barriers were subsequently identified within the COM-B framework for the following HAP mitigation interventions: outdoor cooking, removing children from the cooking area and Liquid Petroleum Gas (LPG) use. Of the 16 interviewed, 12 cooked outdoors (75%), two (12.5%) cooked indoors (in the main home) and two (12.5%) in a separate kitchen. Despite the majority cooking outdoors, this was reported not to be a favourable cooking location. Levels of awareness of HAP sources and knowledge of the health effects of air pollution were observed to be limited, reducing women’s capability to change, along with stated barriers of cost, housing constraints and safety. Factors out of the individuals’ control (opportunities) included weather, socio-economic and educational factors. Preconceived beliefs, experiencing smoke reduction and the briefly described short-term health effects, directed motivation. Furthermore, participants identified a need for community-based education as a facilitator to changing their behaviour. Despite a high level of observed motivation towards reducing HAP exposure, many women lacked the capability and opportunity to change their behaviour. There are research and policy implications concerning development of community-based interventions which involved end-users and relevant stakeholders in the development process.

Interventions to reduce household air pollution (HAP) are key to reducing associated morbidity and mortality in low- and middle- income countries (LMICs); especially among pregnant women and young children. This systematic review aims to determine the effectiveness of interventions aimed to reduce HAP exposure associated with domestic solid biomass fuel combustion, compared to usual cooking practices, for improving health outcomes in pregnant women and children under five in LMIC settings. A systematic review and meta-analysis was undertaken with searches undertaken in MEDLINE, EMBASE, CENTRAL, GIM, ClinicalTrials.gov, and Greenfile in August 2020. Inclusion criteria were experimental, non-experimental, or quasi-experimental studies investigating the impact of interventions to reduce HAP exposure and improve associated health outcomes among pregnant women or children under 5 years. Study selection, data extraction, and quality assessment using the Effective Public Health Practice Project tool were undertaken independently by two reviewers. Seventeen out of 7293 retrieved articles (seven pregnancy, nine child health outcome; 13 studies) met the inclusion criteria. These assessed improved cookstoves (ICS; n = 10 studies), ethanol stoves (n = 1 study), and Liquefied Petroleum Gas (LPG; n = 2 studies) stoves interventions. Meta-analysis showed no significant effect of ICS interventions compared to traditional cooking for risk of preterm birth (n = 2 studies), small for gestational age (n = 2 studies), and incidence of acute respiratory infections (n = 6 studies). Although an observed increase in mean birthweight was observed, this was not statistically significant (n = 4). However, ICS interventions reduced the incidence of childhood burns (n = 3; observations = 41 723; Rate Ratio: 0.66 [95% CI: 0.45-0.96]; I2 : 46.7%) and risk of low birth weight (LBW; n = 4; observations = 3456; Odds Ratio: 0.73 [95% CI: 0.61-0.87]; I2 : 21.1%). Although few studies reported health outcomes, the data indicate that ICS interventions were associated with reduced risk of childhood burns and LBW. The data highlight the need for the development and implementation of robust, well-reported and monitored, community-driven intervention trials with longer-term participant follow-up.

In utero exposure to household air pollution (HAP) from polluting cooking fuels has been linked to adverse pregnancy outcomes including low birthweight (LBW). No previous study in Uganda has attempted to investigate the association between the different types of biomass cooking fuels and LBW. This study was conducted to investigate the association between wood and other biomass cooking fuel use with increased risk of LBW, using the 2016 Uganda Demographic and Health Survey for 15,270 live births within five years prior to interview. LBW, defined as birthweight of <2500 g, was estimated from maternal recall and health cards. Association between household exposure to the different solid biomass cooking fuels and LBW was determined using multivariable logistic regression. Biomass cooking fuels were used in 99.6% of the households, with few (0.3%) using cleaner fuels and 0.1% with no cooking, while the prevalence of LBW was 9.6% of all live-births. Although the crude analysis suggested an association between wood fuel use and LBW compared to other biomass and kerosene fuel use (AOR: 0.82; 95% CI: 0.67–1.00), after adjusting for socio-demographic and obstetric factors, no association was observed (AOR: 0.94; 95% CI: 0.72–1.22). LBW was significantly more likely among female neonates (AOR: 1.32 (95% CI: 1.13–1.55) and neonates born to mothers living in larger households (AOR: 1.03; 95% CI: 1.00–1.07). LBW was significantly less likely among neonates delivered at term (AOR: 0.39; 95% CI: 0.31–0.49), born to women with secondary or tertiary level of education (AOR: 0.80; 95% CI: 0.64–1.00), living in households with a higher wealth index (AOR: 0.69; 95% CI: 0.50–0.96), Eastern (AOR: 0.76; 95% CI:0.59–0.98) and Northern (AOR: 0.75; 95% CI: 0.57–0.99) regions. The study findings suggest inconclusive evidence regarding the association between the use of wood compared to other biomass and kerosene cooking fuels and risk of LBW. Given the close observed association between socioeconomic status and LBW, the Ugandan government should prioritize public health actions which support female education and broader sustainable development to improve household living standards in this setting.

In 2019, a domestic raw coal ban (RCB) was introduced in Ulaanbaatar, Mongolia. Coal-briquettes have since been promoted in Ger district households, however implications for carbon monoxide (CO) exposure remains uncertain. We obtained 48-hour indoor CO concentrations in 23 Ger district households and compared these to 10 raw-coal households. Information on household characteristics, fuel use behaviour and stove venting practices was collected by survey. Mean 48-hour CO concentrations in coal-briquette households was 6.1 ppm (range 1.5–35.8 ppm) with no signfiicant differences by household, stove or venting factors. Peak time-weighted average CO concentrations exceeded WHO Indoor Air Quality guidelines in 9 (39%) households; with all surpassing the 8-hour guideline (>8.6 ppm); 3(13%) the 24-hour guideline (>6 ppm) and 2(9%) the 1-hour guideline (>30 ppm). Median CO levels were significantly lower in coal-briquette compared to raw coal households (p = 0.049). Indoor CO reduction was associated with RCB implementation although hazardous levels persist in this setting.

Background: The World Health Organisation reported that 45% of global acute respiratory infection (ARI) deaths in children under five years are attributable to household air pollution, which has been recognised to be strongly associated with solid biomass fuel usage in domestic settings. The introduction of legislative restrictions for charcoal production or purchase can result in unintended consequences, such as reversion to more polluting biomass fuels such as wood; which may increase health and environmental harms. However, there remains a paucity of evidence concerning the relative health risks between wood and charcoal. This study compares the risk of respiratory symptoms, ARI, and severe ARI among children aged under five years living in wood and charcoal fuel households across 30 low- and middle-income countries. Methods: Data from children (N = 475,089) residing in wood or charcoal cooking households were extracted from multiple population-based Demographic and Health Survey databases (DHS) (N = 30 countries). Outcome measures were obtained from a maternal report of respiratory symptoms (cough, shortness of breath and fever) occurring in the two weeks prior to the survey date, generating a composite measure of ARI (cough and shortness of breath) and severe ARI (cough, shortness of breath and fever). Multivariable logistic regression analyses were implemented, with adjustment at individual, household, regional and country level for relevant demographic, social, and health-related confounding factors. Results: Increased odds ratios of fever (AOR: 1.07; 95% CI: 1.02–1.12) were observed among children living in wood cooking households compared to the use of charcoal. However, no association was observed with shortness of breath (AOR: 1.03; 95% CI: 0.96–1.10), cough (AOR: 0.99; 95% CI: 0.95–1.04), ARI (AOR: 1.03; 95% CI: 0.96–1.11) or severe ARI (AOR: 1.07; 95% CI: 0.99–1.17). Within rural areas, only shortness of breath was observed to be associated with wood cooking (AOR: 1.08; 95% CI: 1.01–1.15). However, an increased odds ratio of ARI was observed in Asian (AOR: 1.25; 95% CI: 1.04–1.51) and East African countries (AOR: 1.11; 95% CI: 1.01–1.22) only. Conclusion: Our population-based observational data indicates that in Asia and East Africa there is a greater risk of ARI among children aged under 5 years living in wood compared to charcoal cooking households. These findings have major implications for understanding the existing health impacts of wood-based biomass fuel usage and may be of relevance to settings where charcoal fuel restrictions are under consideration.

Background: Household air pollution associated with biomass (wood, dung, charcoal, and crop residue) burning for cooking is estimated to contribute to approximately 4 million deaths each year worldwide, with the greatest burden seen in low and middle-income countries. We investigated the relationship between solid fuel type and respiratory symptoms in Uganda, where 96% of households use biomass as the primary domestic fuel. Materials and Methods: Cross-sectional study of 15,405 pre-school aged children living in charcoal or wood-burning households in Uganda, using data from the 2016 Demographic and Health Survey. Multivariable logistic regression analysis was used to identify the associations between occurrence of a cough, shortness of breath, fever, acute respiratory infection (ARI) and severe ARI with cooking fuel type (wood, charcoal); with additional sub-analyses by contextual status (urban, rural). Results: After adjustment for household and individual level confounding factors, wood fuel use was associated with increased risk of shortness of breath (AOR: 1.33 [1.10–1.60]), fever (AOR: 1.26 [1.08–1.48]), cough (AOR: 1.15 [1.00–1.33]), ARI (AOR: 1.36 [1.11–1.66] and severe ARI (AOR: 1.41 [1.09–1.85]), compared to charcoal fuel. In urban areas, Shortness of breath (AOR: 1.84 [1.20–2.83]), ARI (AOR: 1.77 [1.10–2.79]) and in rural areas ARI (AOR: 1.23 [1.03–1.47]) and risk of fever (AOR: 1.23 [1.03–1.47]) were associated with wood fuel usage. Conclusions: Risk of respiratory symptoms was higher among children living in wood compared to charcoal fuel-burning households, with policy implications for mitigation of associated harmful health impacts.