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Background: An estimated 3 billion people, largely in low- and middle-income countries, rely on unclean fuels for cooking, heating, and lighting to meet household energy needs. The resulting exposure to household air pollution (HAP) is a leading cause of pneumonia, chronic lung disease, and other adverse health effects. In the last decade, randomized controlled trials of clean cooking interventions to reduce HAP have been conducted. We aim to provide guidance on how to interpret the findings of these trials and how they should inform policy makers and practitioners.Methods: We assembled a multidisciplinary working group of international researchers, public health practitioners, and policymakers with expertise in household air pollution from within academia, the American Thoracic Society, funders, nongovernmental organizations, and global organizations, including the World Bank and the World Health Organization. We performed a literature search, convened four sessions via web conference, and developed consensus conclusions and recommendations via the Delphi method.Results: The committee reached consensus on 14 conclusions and recommendations. Although some trials using cleaner-burning biomass stoves or cleaner-cooking fuels have reduced HAP exposure, the committee was divided (with 55% saying no and 45% saying yes) on whether the studied interventions improved measured health outcomes.Conclusions: HAP is associated with adverse health effects in observational studies. However, it remains unclear which household energy interventions reduce exposure, improve health, can be scaled, and are sustainable. Researchers should engage with policy makers and practitioners working to scale cleaner energy solutions to understand and address their information needs.

Women and children in rural regions of low-income countries are exposed to high levels of household air pollution (HAP) as they traditionally tend to household chores such as cooking with biomass fuels. Early life exposure to air pollution is associated with aeroallergen sensitization and developing allergic diseases at older ages. This prospective cohort study assigned HAP-reducing chimney stoves to 557 households in rural Guatemala at different ages of the study children. The children's air pollution exposure was measured using personal CO diffusion tubes. Allergic outcomes at 4-5 years old were assessed using skin prick tests and International Study of Asthma and Allergies in Childhood (ISAAC)-based questionnaires. Children assigned to improved stoves before 6 months old had the lowest HAP exposure compared to the other groups. Longer exposure to the unimproved stoves was associated with higher risks of maternal-reported allergic asthma (OR = 2.42, 95% CI: 1.11-5.48) and rhinitis symptoms (OR = 2.01, 95% CI: 1.13-3.58). No significant association was found for sensitization to common allergens such as dust mites and cockroaches based on skin prick tests. Reducing HAP by improving biomass burning conditions might be beneficial in preventing allergic diseases among children in rural low-income populations.

BackgroundHousehold air pollution from solid fuels is a leading risk factor for morbidity and mortality worldwide. Pregnant women's exposure to polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs), two components of solid-fuel smoke, is associated with adverse birth outcomes. Even with improved solid-fuel stoves, exposure to PAHs and VOCs remains high. Therefore, cleaner cooking fuels need to be prioritized.ObjectiveWe aimed to quantify exposure reduction to PAHs and VOCs among pregnant women in rural Guatemala with a liquefied petroleum gas (LPG) stove intervention.Materials and methodsUrine from pregnant women (N = 50) was collected twice: at

BackgroundThree billion people use solid cooking fuels, and 4 million people die from household air pollution annually. Shifting households to clean fuels, like liquefied petroleum gas (LPG), may protect health only if stoves are consistently used. Few studies have used an implementation science framework to systematically assess "de-implementation" of traditional stoves, and none have done so with pregnant women who are more likely to adopt new behaviors. We evaluated an introduced LPG stove coupled with a phased behavioral intervention to encourage exclusive gas stove use among pregnant women in rural Guatemala.MethodsWe enrolled 50 women at

BackgroundHousehold air pollution is a major contributor to death and disability worldwide. Over 95% of rural Guatemalan households use woodstoves for cooking or heating. Woodsmoke contains carcinogenic or fetotoxic polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Increased PAHs and VOCs have been shown to increase levels of oxidative stress.ObjectiveWe examined PAH and VOC exposures among recently pregnant rural Guatemalan women exposed to woodsmoke and compared exposures to levels seen occupationally or among smokers.MethodsUrine was collected from 23 women who were 3 months post-partum three times over 72h: morning (fasting), after lunch, and following dinner or use of wood-fired traditional sauna baths (samples=68). Creatinine-adjusted urinary concentrations of metabolites of four PAHs and eight VOCs were analyzed by liquid chromatography-mass spectrometry. Creatinine-adjusted urinary biomarkers of oxidative stress, 8-isoprostane and 8-OHdG, were analyzed using enzyme-linked immunosorbent assays (ELISA). Long-term (pregnancy through 3 months prenatal) exposure to particulate matter and airborne PAHs were measured.ResultsWomen using wood-fueled chimney stoves are exposed to high levels of particulate matter (median 48h PM2.5 105.7μg/m3; inter-quartile range (IQR): 77.6-130.4). Urinary PAH and VOC metabolites were significantly associated with woodsmoke exposures: 2-naphthol (median (IQR) in ng/mg creatinine: 295.9 (74.4-430.9) after sauna versus 23.9 (17.1-49.5) fasting; and acrolein: 571.7 (429.3-1040.7) after sauna versus 268.0 (178.3-398.6) fasting. Urinary PAH (total PAH: ρ=0.89, p0.85) or PAH and VOC biomarkers (ρ=-0.20 to 0.38, p>0.07). Urinary metabolite concentrations were significantly greater than those of heavy smokers (mean cigarettes/day=18) across all PAHs. In 15 (65%) women, maximum 1-hydroxypyrene concentrations exceeded the occupational exposure limit of coke-oven workers.ConclusionsThe high concentrations of urinary PAH and VOC metabolites among recently pregnant women is alarming given the detrimental fetal and neonatal effects of prenatal PAH exposure. As most women used chimney woodstoves, cleaner fuels are critically needed to reduce smoke exposure.

RationaleHousehold air pollution (HAP) from solid fuel combustion is a major contributor to the global burden of disease, with considerable impact from respiratory infections in children. The impact of HAP on lung function is unknown.ObjectivesThe Childhood Exposure to Respirable Particulate Matter (CRECER) prospective cohort study followed Guatemalan children who participated in the Randomised Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) trial of a chimney stove intervention to determine the effect of early childhood HAP exposure on growth of lung function.MethodsRESPIRE households with pregnant women or infant children were randomised to receive a chimney stove at the beginning or at the end of the 18-month trial. During CRECER, a subset of these children, as well as children from households with newly installed stoves, were followed with spirometry beginning at age 5. Biomass smoke exposure was measured using personal carbon monoxide tubes. Two-stage regression models were employed to analyse associations with lung function growth.Measurements and main resultsLongitudinal peak expiratory flow (PEF) and FEV1 data were available for 443 and 437 children, respectively, aged 5-8 (mean follow-up 1.3 years). Decreases in PEF growth of 173 mL/min/year (95% CI -341 to -7) and FEV1 of 44 mL/year (95% CI -91 to 4) were observed with stove installation at 18 months compared with stove installation at birth in analyses adjusted for multiple covariates. No statistically significant associations were observed between personal HAP exposure and lung function.ConclusionsA significant decrease in PEF growth and a large non-significant decrease in FEV1 growth were observed with later stove installation. Additional studies including longer follow-up and cleaner stoves or fuels are needed.

Low birth weight is associated with exposure to air pollution during pregnancy. The purpose of this study was to evaluate whether null polymorphisms of Glutathione S-transferases (GSTs), specifically GSTM1 and GSTT1 genes in infants or mothers, modify the association between high exposures to household air pollution (HAP) from cooking fires and birth weight. Pregnant women in rural Guatemala were randomized to receive a chimney stove or continue to use open fires for cooking. Newborns were measured within 48 h of birth. 132 mother-infant pairs provided infant genotypes (n=130) and/or maternal genotypes (n=116). Maternal null GSTM1 was associated with a 144 g (95% CI, -291, 1) and combined maternal/infant null GSTT1 was associated with a 155 g (95% CI, -303, -8) decrease in birth weight. Although there was a trend toward higher birth weights with increasing number of expressed GST genes, the effect modification by chimney stove use was not demonstrated.

BackgroundA growing body of evidence indicates a relationship between household indoor air pollution from cooking fires and adverse neonatal outcomes, such as low birth weight (LBW), in resource-poor countries.ObjectiveWe examined the effect of reduced wood smoke exposure in pregnancy on LBW of Guatemalan infants in RESPIRE (Randomized Exposure Study of Pollution Indoors and Respiratory Effects).MethodsPregnant women (n = 266) either received a chimney stove (intervention) or continued to cook over an open fire (control). Between October 2002 and December 2004 we weighed 174 eligible infants (69 to mothers who used a chimney stove and 105 to mothers who used an open fire during pregnancy) within 48 hr of birth. Multivariate linear regression and adjusted odds ratios (ORs) were used to estimate differences in birth weight and LBW (< 2,500 g) associated with chimney-stove versus open-fire use during pregnancy.ResultsPregnant women using chimney stoves had a 39% reduction in mean exposure to carbon monoxide compared with those using open fires. LBW prevalence was high at 22.4%. On average, infants born to mothers who used a stove weighed 89 g more [95% confidence interval (CI), -27 to 204 g] than infants whose mothers used open fires after adjusting for maternal height, diastolic blood pressure, gravidity, and season of birth. The adjusted OR for LBW was 0.74 (95% CI, 0.33-1.66) among infants of stove users compared with open-fire users. Average birth weight was 296 g higher (95% CI, 109-482 g) in infants born during the cold season (after harvest) than in other infants; this unanticipated finding may reflect the role of maternal nutrition on birth weight in an impoverished region.ConclusionsA chimney stove reduced wood smoke exposures and was associated with reduced LBW occurrence. Although not statistically significant, the estimated effect was consistent with previous studies.

Introduction: Approximately three billion people in Asia, Africa, and the Americas cook with biomass, cleaner cooking technologies with the potential to reduce household air pollution exposure. It is necessary to assess the adoption and long-term use of these stoves, measure perceived benefits among users, and use this information to provide feedback to programs that are implementing new cooking technologies. The aim of this study is to determine the level of adoption and impact of improved biomass cookstoves in the rural area of Lambayeque, Peru, in 2017. Methods: A descriptive cross-sectional study was conducted. A total of 52 homes were surveyed in the districts of Pacora and Íllimo where improved biomass stoves were introduced between 2005 and 2013. A questionnaire for the assessment of adoption and impact indexes proposed by the Global Alliance for Clean Cookstoves was applied. The STROBE checklist was used. Results: The mean number of years with the improved biomass cookstove was 9.1 (standard deviation: 2.9); 51.9% always used the improved stove, and 34.6% never used it due to destruction during the El Niño phenomenon in 2017. The median impact index was 5.62; 19.2% had a very good/good adoption. The median adoption index was 6.5; 25% had a very high/high impact. The use of the traditional or open fire biomass stove persisted in 61.5% of the houses. Conclusion: The adoption and impact of improved biomass cookstoves were acceptable, but traditional stove use persisted in more than half of the houses. Households used a mix of different stove technologies. Gas stoves were used more frequently for breakfast or dinner, while the traditional biomass stoves were used for larger lunchtime meals. [ABSTRACT FROM AUTHOR]

Over the past several decades, important advances have been made in the United States to ensure that our residents breathe clean air. Still, nearly 12 million homes in this country burn wood for heating. Globally, 3 billion people, or close to half of the world's population, depend on polluting solid fuels such as wood for daily cooking and heating. Unlike in the United States where stoves used for heating are vented, many homes in low-income countries use simple stoves that often lack chimneys, leading to toxic amounts of smoke inside and outside the home. Household air pollution from these fires is the 16th leading risk factor for death and disability worldwide. Childhood pneumonia, chronic obstructive pulmonary disease, and cardiovascular disease have all been associated with household air pollution globally, yet many nurses are not aware of this burden when caring for immigrants and refugees residing in the United States. Global organizations are working to provide access to clean cookstoves (those that run on electricity, solar power, or liquid fuel), and nurses can get involved. This is one step toward improving the lives of vulnerable populations in the United States and worldwide. This series is in collaboration with the Alliance of Nurses for Healthy Environments (https://envirn.org). [ABSTRACT FROM AUTHOR]

Household air pollution is the sixth leading risk factor for premature mortality in Guatemala. Households in Guatemala are gradually adopting liquefied petroleum gas (LPG) stoves, but a strong tradition of woodstove use persists. We conducted a mixed-methods study of LPG stove use in peri-urban Guatemala. We used knowledge, attitudes and practices surveys with 187 LPG stove owners who also used woodstoves to identify perceptions of stove and cooking practices. Barriers to sustained use of LPG stoves were evaluated through focus groups, participant observations with stove users, and key informant interviews with community leaders. Seven themes emerged that explain household decisions to use LPG stoves: (1) The “new technology” should be framed in terms of what the “old technology” lacks, (2) income is not a predictor of gas stove acquisition but may predict sustained use, (3) men are key decision-makers but messages about LPG do not target them, (4) when stoves are viewed as “prize possessions” they may not be used, (5) collective fear about gas stoves is not based on personal experience, but on “stories we hear,” (6) sustained LPG use is hampered by two major factors, seasonally available wood and LPG retailers who are perceived as dishonest, and (7) wood fuel collection is a time to enjoy the company of friends and family and is not “drudgery.” National policies should promote the use of clean cookstove technologies in peri-urban and rapidly urbanizing areas in Guatemala where LPG stoves are in use, but used intermittently, instead of the current plan to install 100,000 “improved” woodstoves by 2032. This could be done by improving dependable cylinder distribution services, targeting gas safety and promoting positive health messages that appeal to men, as well as women. [ABSTRACT FROM AUTHOR]

Low birth weight is associated with exposure to air pollution during pregnancy. The purpose of this study was to evaluate whether null polymorphisms of Glutathione S-transferases (GSTs), specifically GSTM1 and GSTT1 genes in infants or mothers, modify the association between high exposures to household air pollution (HAP) from cooking fires and birth weight. Pregnant women in rural Guatemala were randomized to receive a chimney stove or continue to use open fires for cooking. Newborns were measured within 48 h of birth. 132 mother–infant pairs provided infant genotypes ( n = 130) and/or maternal genotypes ( n = 116). Maternal null GSTM1 was associated with a 144 g (95% CI, −291, 1) and combined maternal/infant null GSTT1 was associated with a 155 g (95% CI, −303, −8) decrease in birth weight. Although there was a trend toward higher birth weights with increasing number of expressed GST genes, the effect modification by chimney stove use was not demonstrated. [ABSTRACT FROM AUTHOR]

The Household Air Pollution Intervention Network trial is a multi-country study on the effects of a liquefied petroleum gas (LPG) stove and fuel distribution intervention on women's and children's health. There is limited data on exposure reductions achieved by switching from solid to clean cooking fuels in rural settings across multiple countries. As formative research in 2017, we recruited pregnant women and characterized the impact of the intervention on personal exposures and kitchen levels of fine particulate matter (PM 2.5) in Guatemala, India, and Rwanda. Forty pregnant women were enrolled in each site. We measured cooking area concentrations of and personal exposures to PM 2.5 for 24 or 48 h using gravimetric-based PM 2.5 samplers at baseline and two follow-ups over two months after delivery of an LPG cookstove and free fuel supply. Mixed models were used to estimate PM 2.5 reductions. Median kitchen PM 2.5 concentrations were 296 μg/m3 at baseline (interquartile range, IQR: 158–507), 24 μg/m3 at first follow-up (IQR: 18–37), and 23 μg/m3 at second follow-up (IQR: 14–37). Median personal exposures to PM 2.5 were 134 μg/m3 at baseline (IQR: 71–224), 35 μg/m3 at first follow-up (IQR: 23–51), and 32 μg/m3 at second follow-up (IQR: 23–47). Overall, the LPG intervention was associated with a 92% (95% confidence interval (CI): 90–94%) reduction in kitchen PM 2.5 concentrations and a 74% (95% CI: 70–79%) reduction in personal PM 2.5 exposures. Results were similar for each site. The intervention was associated with substantial reductions in kitchen and personal PM 2.5 overall and in all sites. Results suggest LPG interventions in these rural settings may lower exposures to the WHO annual interim target-1 of 35 μg/m3. The range of exposure contrasts falls on steep sections of estimated exposure-response curves for birthweight, blood pressure, and acute lower respiratory infections, implying potentially important health benefits when transitioning from solid fuels to LPG. • There was high uptake of an LPG stove and fuel intervention in 3 rural settings. • The LPG intervention was associated with a 92% reduction in kitchen PM 2.5 levels. • The intervention was associated with a 74% reduction in personal exposure to PM 2.5 • Maternal PM 2.5 exposure was reduced to the WHO annual interim target-1 of 35 μg/m3. • Results from 3 countries indicate switching to clean fuel could improve health. Capsule summary: LPG stove and fuel intervention can reduce kitchen area and personal PM 2.5 exposure levels in a pilot study of clean cookstove intervention trial. This strongly suggests switching to clean cook can improve health. [ABSTRACT FROM AUTHOR]

Approximately 3.8 billion people in low- and middle-income countries use unclean fuels as a source of primary cooking fuel as well as for heating. For pregnant women, the toxic chemicals produced by combustion of unclean fuels not only affect women's health directly, but particulate matter and carbon monoxide are absorbed in maternal blood and cross the placental barrier impairing fetal tissue growth. PRISMA 2009 guidelines were used for this systematic review. The inclusion criteria were quantitative, peer reviewed journal articles published within a date range of May 1, 2013–June 12, 2021 examining birth outcomes related to household air pollution from type of cooking fuel in low- and middle-income countries. The quality of available evidence was evaluated using the Office of Health Assessment and Translation (OHAT) risk of bias rating tool. Of the 553 studies screened, 23 satisfied the inclusion criteria. Of the studies that met the inclusion criteria, 14 were cross-sectional, 5 cohort, 1 case-control and 3 randomized control trials conducted across 15 different countries. A range of birth outcomes are reported across studies including birthweight (19), small for gestational age (6), spontaneous abortion (3), preterm birth (6), stillbirth (7) and neonatal mortality (6). The reviewed studies presented evidence for an increased risk of low birth weight (LBW), preterm birth (PTB), small for gestational age (SGA), stillbirth, neonatal mortality and reduction in birthweight with solid fuel and kerosene use compared to cleaner fuels like gas and LPG. Systematically reviewing the evidence and risk of bias ratings illuminated several gaps in the current literature related to exposure assessment, outcome measurement and adequacy of adjustment for confounding. [ABSTRACT FROM AUTHOR]

The article presents a study concerning the effect of household air pollution reduction in children with pneumonia in Guatemala. Researchers have conducted a parallel randomized control trial using an open indoor wood fires used for cooking. Findings reveal the association of 50 % exposure reduction in physician-diagnosed pneumonia in a exposure-response analysis. The study also showed that the reduction on wood smoke exposure does not reduce pneumonia in children who are younger than 18 months.