Burden Of Household Air Pollution Research Articles

A preliminary assessment of the health impacts of indoor air contaminants determined using the DALY metric

Common metrics used for assessing air quality are based on guidelines and/or standards for regulating concentrations that should not be exceeded over a period. Exceeding those values would represent problematic situations. A lack of agreement on appropriate norms or standards deems this approach sub-optimal. Moreover, this approach does not relate a proportion of exceedance to specific health outcomes. A need to develop health-centered IAQ metrics that can quantify burden of disease in terms of epidemiological evidence of population morbidity and mortality supported by the best knowledge of health effects, is pressing. This work proposes an approach that harnesses the advantages of using disability adjusted life years (DALYs) as a valuable metric to quantify and rank the burden of household air pollution, as a global perspective. Two methods were used to compute DALYs, one mainly based on incidence data and another mainly based on effect factors (i.e. DALYs per unit-intake of contaminant of interest). The methods are based on the following parameters: risk estimates, baseline incidence rates, damage factors, indoor air contaminant concentrations, human toxicological & epidemiological effect factors, dose–response factors, cancer-related variables and breathing rates. Systematic searches and reviews of peer-reviewed literature (including systematic reviews and meta-analyses) were performed to find information on said input parameters. Meta-analysis was used to pooled and synthesise data from different studies. A Monte Carlo approach was used to model results in DALYs lost. Over 1000 articles were revised and overall ∼200 unique sources were used as sources of data. Ten contaminants were accounted for with specific risk estimates and damage factors data, for which human epidemiological effect factors were derived. Representative concentrations of 45 contaminants were calculated. Thirty-nine contaminants were accounted for human toxicological effect factors. Total pooled DALYs were estimated per 100,000 exposed population with corresponding uncertainty intervals. Estimated population-averaged annual cost, in DALYs lost, of chronic air contaminant inhalation in dwellings indicate that the contaminants with highest median DALY loss estimates are PM10 and PM2.5 (magnitudes of 103); PMcoarse, formaldehyde and NO2 could be found with magnitudes of 102; contaminants with magnitudes of 101 include radon and ozone, finally SO2 and acrolein would have magnitudes of 10°; mould-related bioaerosols could be of interest as well. The updated strategies allowed for the quantification of contaminants and health outcomes that were not accounted for in previous works. Computed DALYs have lower uncertainty intervals than those previously proposed. The updated methodology presented in this study may be used to assess cumulative health impacts of indoor air contaminants.

Biomass fuel use and birth weight among term births in Nigeria.

Despite the high burden of household air pollution from biomass fuel in sub-Saharan Africa, the association of prenatal biomass fuel exposure and birth weight as a continuous variable among term births has not been extensively studied. In this study, our primary aim is to estimate the association between biomass cooking fuel and birth weight among term births in Kaduna, northwestern Nigeria. For replication, we also evaluated this association in a larger and nationally representative sample from the 2018 Nigerian Demographic and Health Survey (DHS). Our primary analysis included 1,514 mother-child pairs recruited from Kaduna, in northwestern Nigeria, using the Child Electronic Growth Monitoring System (CEGROMS). Replication analysis was conducted using data from 6,975 mother-child pairs enrolled in 2018 Nigerian DHS. The outcome variable was birth weight, and the exposure was cooking fuel type, categorized in CEGROMS as liquefied petroleum gas, kerosene, or biomass fuel, and in the DHS as low pollution fuel, kerosene, or biomass fuel. We estimated covariate adjusted associations between birth weight and biomass fuel exposure in CEGROMS using linear regression and using linear mixed model in the DHS. In CEGROMS, adjusting for maternal age, education, parity, BMI at birth, and child sex, mothers exposed to biomass fuel gave birth to infants who were on average 113g lighter (95% CI -196 to -29), than those using liquified petroleum gas. In the 2018 Nigeria DHS data, compared to low pollution fuel users, mothers using biomass had infants weighing 50g (95% CI -103 to 2) lower at birth. Exposure to biomass cooking fuel was associated with lower birth weight in our study of term newborns in Kaduna, Nigeria. Data from the nationally representative DHS provide some support for these findings.

Maternal exposure to biomass fuel and birthweight in Kaduna, Northwestern Nigeria: Results from the Child Electronic Growth Monitoring System (CEGROMS)

BACKGROUND AND AIM: Despite the high burden of household air pollution from solid biomass fuel in sub-Saharan Africa, the association of prenatal biomass fuel exposure and birth weight as a continuous variable and independent of preterm birth has not been extensively studied. In this study, we aimed to determine the association of prenatal exposure to biomass fuel with birthweight analyzed as a continuous variable among term births in a Nigerian population. METHODS: This cross-sectional study was conducted at the Child Welfare Clinic of Barau Dikko Teaching Hospital, Kaduna (Kaduna State, Northwestern Nigeria), an urban metropolis with the country's fourth-largest population. We obtained data from the Child Electronic Growth Monitoring System (CEGROMS), a database of all women who brought their newborns to the study site for BCG vaccination and growth monitoring around the time of birth. A total of 1348 women with term births and information on birthweight, cooking fuel type, and other risk factors met the inclusion criteria. We used linear regression to estimate the adjusted associations (β and 95% confidence interval (CI)) between birthweight and biomass fuel exposure. RESULTS:Thirteen percent of mothers used biomass fuel relative to 78.5% using liquified petroleum gas (LPG) and 8.5% using kerosene. On average, infants of mothers exposed to biomass fuel were 111g lighter (95% CI −205,−18), compared with those of mothers using LPG adjusted for maternal age, education, and parity. Kerosene use resulted in a 10 g (95% CI -107; 86) reduction in mean birth weight compared to mothers using LPG. CONCLUSIONS:Maternal exposure to biomass fuel was associated with shifting of the birth weight distribution among term newborns. KEYWORDS: Biomass fuel, House air pollution, birthweight, Nigeria

Use of liquefied petroleum gas in Puno, Peru: Fuel needs under conditions of free fuel and near-exclusive use

Reducing the burden of household air pollution could be achieved with exclusive adoption of cleaner fuels such as liquefied petroleum gas (LPG). However, we lack understanding of how much LPG is required to support exclusive use and how household characteristics affect this quantity. This paper used data from 90 participants in the Cardiopulmonary outcomes and Household Air Pollution (CHAP) trial in Puno, Peru who received free LPG deliveries for one year. Households with a mean of four members that cooked nearly exclusively (>98%) with LPG used an average of 19.1kg (95% CI 18.5 to 19.6) of LPG per month for tasks similar to those done with the traditional biomass stove. LPG use per month was 0.5kg higher for each additional pig or dog owned (p=0.003), 0.7kg higher for each additional household member (p<0.001), 0.3kg higher for households in the second-lowest compared to the lowest wealth quintile (p=0.01), and 1.1kg higher if the household had previously received subsidized LPG (p=0.05). LPG use per month was 1.1kg lower during the rainy season (p<0.001) and 1.7kg lower during the planting season (p<0.001) compared to the cold and harvest seasons, despite the fact that LPG was not typically used for space heating. LPG use decreased by 0.05kg per month over the course of one year after receiving the LPG stove (p=0.02). These results suggest that achieving exclusive LPG use in Puno, Peru requires that rural residents have affordable access to an average of two 10kg LPG tanks per month. Conducting similar investigations in other countries could help policymakers set and target LPG subsidies to ensure that households have access to enough LPG to achieve exclusive LPG use and the potential health benefits.

Beyond cost: Exploring fuel choices and the socio-cultural dynamics of liquefied petroleum gas stove adoption in Peru

Reducing the burden of household air pollution requires that cleaner fuels such as liquefied petroleum gas (LPG) be used nearly exclusively. However, exclusive adoption has been challenging in low- and middle-income countries. Previous studies have found that economic, social, and cultural barriers often impede adoption. We conducted in-depth qualitative interviews with 22 participants in a research trial where LPG was provided for free in Puno, Peru. We aimed to determine whether social and cultural barriers to LPG use persisted when monetary costs to the households were removed, and what factors influenced exclusive adoption of LPG in a cost-free context. Facilitators of LPG use included: support from study staff, family support, time savings, previous experience with LPG, stove design, ability to use existing pots, smoke reductions, desire for cleanliness, removal of traditional stoves, and perceptions of luck. Barriers to LPG use included: fears of LPG, problems with LPG brands, delays in obtaining LPG refills, social pressure, perceived incompatibility of traditional dishes, perceived inability to use clay pots, separate kitchens for LPG and traditional stoves, designated pots for use on the traditional stove, and lack of heat. However, these barriers did not prevent participants from using LPG nearly exclusively. Results suggest that social and cultural barriers to exclusive LPG use can be overcome when LPG stoves and fuel are provided at no cost to users and supplemented with behavioral support. Governments should evaluate the economic feasibility and sustainability of LPG subsidization, considering the potential benefits of exclusive LPG use.

A single-arm trial examining the feasibility, acceptability and distribution of LPG cookstoves and gas cylinders to pregnant women living in rural Bangladesh, in preparation for The Poriborton

TPS 722: Low and middle income countries: indoor air pollutants, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background/Aim: The burden of household air pollution on perinatal mortality has not been accurately defined. Our overall aim was to develop a protocol for a cluster randomised controlled trial (cRCT) to assess the impact of liquid petroleum gas (LPG) cooking compared to usual cooking on perinatal mortality in pregnant women in rural Bangladesh (ACTRN12618001214224). For this study we aimed to assess the feasibility of the planned trial and the barriers/facilitators of distributing LPG to rural households. Methods: We used a mixed method iterative design. We included pregnant women, their families, and local LPG stakeholders. We distributed LPG to households for 3 months and assessed process issues, acceptability and cooking/food behaviours. We interviewed LPG stakeholders, and conducted focus groups and interviews with users. The study had ethical approval and was conducted in Basail, north of Dhaka. Results: 50 pregnant women, and their family members trialed LPG. Initial distribution of LPG was hampered by process issues (fees, storage, timing) most of these were due to the lack of an established supply chain. Initial safety concerns were overcome with safety measures and training, LPG cooking was very acceptable, and all users reported a preference for continued use, fuel-sparing was heavily practised. Continuous LPG supply was hampered by the ad hoc supply chain. LPG stakeholders reported that LPG demand differed by season. Conclusions: Our iterative study meant that all issues were manageable. Implications for a larger trial include: ensuring safety, information to support continuous LPG use to ensure efficacy of the intervention is critical, a well-developed supply chain is essential for continuous supply, and changes in LPG demand due to season will need to be monitored to ensure timely cylinder replenishment. This was a very beneficial study for our protocol development, and overall, distributing LPG to pregnant women in rural Bangladesh was feasible.

Impacts of residential energy consumption on the health burden of household air pollution: Evidence from 135 countries

Knowledge about the links between burden from household air pollution (B-HAP) and residential energy consumption (REC) is essential for optimizing residential energy supply mix and improving the quality of indoor air worldwide. However, the literature on this topic from a perspective of energy transition is still lacking. This study investigates the relationship between the variation in the B-HAP and the structural transition of REC using cross-sectional data of 135 countries during 1990–2015. The results indicate that countries with high B-HAP are clustered in Africa and Asia, which are mainly middle- and low-income countries. Meanwhile, with the structural transition of REC, the global B-HAP has exhibited a decreasing trend. Moreover, the findings show that residential electricity use has a greater impact on B-HAP reduction than other household fuels. Although the impacts of liquefied petroleum gas usage changed considerably during the study period, its contribution to reducing the B-HAP remains highly significant, while household natural gas use exhibited a significant and stable effect on B-HAP reduction. In contrast, solid biomass use showed an increasingly adverse impact on the B-HAP, and the impact of coal use on the B-HAP became statistically significant since 2010, with an increasing trend.

An expert survey on the material types used to start cookstoves

Household air pollution generated using solid-fuel cookstoves is a leading risk factor for morbidity and mortality worldwide. Many studies have quantified cookstove emissions with respect to the main fuels used (e.g.,wood, charcoal and other biomass fuels). Anecdotal evidence suggests a variety of fuels are used to ignite cookstoves, however quantitative information on startup fuel types is lacking. Emissions from startup materials contribute to household air pollution. As such, understanding startup practices and the choices of startup materials is integral to understanding the full burden of household air pollution from cookstoves on health and the environment. We conducted an expert elicitation style survey to gather information about startup practices worldwide. Twenty-three respondents from academic and private sectors responded to a survey instrument on cookstove startup, providing information that covered 48 geographic locations across 22 countries. Responses to theopen-ended questions were analyzed to quantify how startup materials vary according to factors such as location, seasonality, and the main cooking fuel/stove type. A wide variety of materials were reportedly used to ignite cookstoves, including many non-biomass materials that may have toxic combustion byproducts. Paper, plastic, agricultural wastes, waxes and other petroleum fuels (e.g.,kerosene), and rubber-like materials (e.g.,tires, footwear) were the most commonly indicated startup materials. Additional materials mentioned included fabrics, plastic packaging, soda bottles, snack food wrappers, and trash. Results from this survey can be used to direct future research on the impacts of startup materials on health and the environment, such as justifying the choice of materials to test in the laboratory.

Cookstove Trials and Tribulations: What Is Needed to Decrease the Burden of Household Air Pollution?

Household air pollution arising from the combustion of dirty-burning fuels in and around the home for cooking and heating (e.g., wood, crop waste, dung, coal) is estimated by WHO to cause around 4 million premature deaths a year, mainly from cardiopulmonary diseases, making it one of the commonest underlying drivers of morbidity and mortality in low- and middle-income countries (LMIC).1 Although not included in the WHO estimates, the use of kerosene for lighting contributes additional morbidity and mortality.2 Although the latest Global Burden of Disease Study 2016 estimates a smaller number of deaths attributable to household air pollution – 2.5 million – it helpfully puts these risks in the context of other risk factors amongst which air pollution is very prominent.3

Research on Emissions, Air quality, Climate, and Cooking Technologies in Northern Ghana (REACCTING): study rationale and protocol.

BackgroundCooking over open fires using solid fuels is both common practice throughout much of the world and widely recognized to contribute to human health, environmental, and social problems. The public health burden of household air pollution includes an estimated four million premature deaths each year. To be effective and generate useful insight into potential solutions, cookstove intervention studies must select cooking technologies that are appropriate for local socioeconomic conditions and cooking culture, and include interdisciplinary measurement strategies along a continuum of outcomes.Methods/DesignREACCTING (Research on Emissions, Air quality, Climate, and Cooking Technologies in Northern Ghana) is an ongoing interdisciplinary randomized cookstove intervention study in the Kassena-Nankana District of Northern Ghana. The study tests two types of biomass burning stoves that have the potential to meet local cooking needs and represent different “rungs” in the cookstove technology ladder: a locally-made low-tech rocket stove and the imported, highly efficient Philips gasifier stove. Intervention households were randomized into four different groups, three of which received different combinations of two improved stoves, while the fourth group serves as a control for the duration of the study. Diverse measurements assess different points along the causal chain linking the intervention to final outcomes of interest. We assess stove use and cooking behavior, cooking emissions, household air pollution and personal exposure, health burden, and local to regional air quality. Integrated analysis and modeling will tackle a range of interdisciplinary science questions, including examining ambient exposures among the regional population, assessing how those exposures might change with different technologies and behaviors, and estimating the comparative impact of local behavior and technological changes versus regional climate variability and change on local air quality and health outcomes.DiscussionREACCTING is well-poised to generate useful data on the impact of a cookstove intervention on a wide range of outcomes. By comparing different technologies side by side and employing an interdisciplinary approach to study this issue from multiple perspectives, this study may help to inform future efforts to improve health and quality of life for populations currently relying on open fires for their cooking needs.