Implementation of clean cookstove interventions and its effects on blood pressure in low-income and middle-income countries: systematic review

Sauveur R, Rouzier V, Inddy J, Hilaire E, Preval F, Yan LD, Mourra N, Ogyu A, Pierre DM, Pape JW, Nash D, McNairy ML. Prevalence of Cooking with Polluting Fuels and Association with Elevated Blood Pressure Among Adults in Port au Prince, Haiti: A Cross-Sectional Analysis

Background

Cooking with polluting fuels is common in low- and middle-income countries and may impact blood pressure, yet data on this association in urban Haiti is limited. This study describes the prevalence of polluting fuel use and indoor cooking, evaluates their associations with blood pressure, and evaluates whether effects are heterogeneous by sex in urban Haiti.

Methods

Using cross-sectional data from the Haiti Cardiovascular Disease Cohort study, prevalence of polluting fuel use and indoor cooking was estimated. The associations between polluting fuel use and indoor cooking with systolic blood pressure (SBP), diastolic blood pressure (DBP) and hypertension (HTN) (mean SBP ≥140 mmHg or mean DBP ≥90 mmHg) were estimated using generalized estimating equations. The interaction between polluting fuel use and sex was also evaluated.

Results

Among 2,931 participants, 58.2% were female and the mean age was 42.0 (SD = 15.9) years. The majority (88.2%) primarily cooked with polluting fuels. Polluting vs clean fuel users tended to have less than a high school education (38.0% vs 22.8%), earn ≤ 1 USD/day (70.5% vs 67.4%), and have high food insecurity (85.0% vs 64.3%). Polluting vs clean fuel users had similar HTN prevalence (adjusted prevalence ratio [aPR] = 0.94, 95% CI: 0.80, 1.10). Average SBP was similar for women (0.99 mmHg, 95% CI: -1.46, 3.44) and lower for men (-4.80 mmHg, 95% CI: -8.24, -1.37) who used polluting vs clean fuels. Cooking indoors vs outdoors was associated with higher HTN prevalence (aPR = 1.12, 95% CI: 1.00, 1.25) and higher average SBP (1.67 mmHg, 95% CI: 0.15, 3.20).

Conclusions

This study demonstrates that most Haitians in Port-au-Prince cook with polluting fuels and often indoors. Those with higher poverty are more exposed, with mixed results in their association with blood pressure. Longitudinal studies are needed to clarify causal relationships and inform interventions promoting clean fuel use. (ClinicalTrials.gov Identifier: NCT03892265).

A Systematic Review and Meta-Analysis Assessing the Impact of Improved Cookstove Technology Trials (ICTs) on Household Air Pollution and Human Health in Sub-Saharan Africa

PURPOSE OF REVIEW

A major contributor to household air pollution (HAP) in sub-Saharan Africa (SSA) is unclean cooking fuel. Improved cookstove technology (ICT) interventions have been promoted as a solution, but their impacts on health are unclear. Our aim is to conduct a systematic review to explore the impacts of ICT interventions on health outcomes in SSA. We conducted a systematic review, following PRISMA guidelines, on ICT interventions in SSA from 2000-present. We performed this search in MEDLINE, PubMed, Web of Science, Web of Science CABI, and EMBASE via ProQuest. Two reviewers assessed each study using predefined inclusion/exclusion criteria and extracted data. We evaluated each study on participant selection, exposure assessment, control comparability, outcomes, analyses, and biases.

RECENT FINDINGS

From 4,461 articles, k = 23 (n = 31,261 individuals) articles described results of ICT interventions on health outcomes. Pooled mean exposure estimates for fine particulate matter (PM2.5) in control and intervention groups were 102.88 µg/m3 (95% confidence interval [CI]I: 52.63, 153.14; I2 96.9%) and 101.76 µg/m3 (95%CI: 57.47, 146.06; I2 98.2%), respectively. Estimates for pooled mean carbon monoxide (CO) were 2.40 ppm (95% CI: 0, 8.33; I2 99.0%) and 1.66 ppm (0, 4.91; I2 98.5%) respectively. Of health outcomes, 19.4% were reported as significantly different between control and intervention groups. There is mixed evidence that ICT interventions influence health outcomes due to heterogeneity in study designs, sample size, stove stacking, etc. ICT interventions may decrease HAP, but other sources of air pollutant exposure are not addressed by improved cookstoves.

Effects of a coal to clean heating policy on acute myocardial infarction in Beijing: a difference-in-differences analysis

BACKGROUND

In 2015, the Chinese Government launched the coal to clean heating policy (CHP), designed to improve air quality and health in China. The CHP banned household coal burning and provided subsidies for clean electric or gas-powered heating for millions of peri-urban and rural households. We aimed to investigate whether the CHP affected the incidence of acute myocardial infarction in Beijing townships.

METHODS

In this quasi-experimental study, we obtained township data on acute myocardial infarction hospital admissions and deaths, exposure to the CHP (yes vs no), and a range of covariates for periods before (Jan 1, 2013, to Dec 31, 2014) and after the CHP began (Jan 1, 2016, to Dec 31, 2017; and Jan 1, 2018, to Dec 31, 2019). The policy was gradually rolled out across villages, and townships in our study were considered exposed to the policy in periods when more than 50% of their villages were assigned into the CHP. We estimated the effect of the CHP on township incidence of acute myocardial infarction for all adults (aged ≥35 years) and separately for sex and older adults (aged ≥65 years) using a difference-in-differences approach that accommodates the progressive roll-out of the policy.

FINDINGS

Of 307 townships in Beijing, we excluded 156 (51%) urban townships where most villages had central heating and were thus ineligible for the CHP. Of the 151 peri-urban and rural Beijing townships considered eligible for the CHP, 75 (50%) townships were exposed to the CHP by the end of 2017 and 92 (61%) by the end of 2019. We estimated an overall reduction of 6·6% (95% CI -12·3 to -0·8) in the incidence of acute myocardial infarction from before to after roll-out of the CHP in exposed townships relative to those not exposed to the policy, with some evidence of larger effects in women (-11·7% [-19·0 to -4·1%]), older adults (-10·7% [-17·4 to -3·6%]), and in townships exposed for longer (-3·5% [-9·5 to 2·8%] after <2 years and -9·7% [-18·3 to -0·5%] after 2-4 years).

INTERPRETATION

Our results provide among the first empirical evidence of possible cardiovascular benefits from a household clean energy policy, and support efforts to implement and assess such policies in China and globally.

FUNDING

Wellcome Trust, the Canadian Institutes for Health Research, and the National Natural Science Foundation of China.

Household Air Pollution Interventions to Improve Health in Low- and Middle-Income Countries: An Official American Thoracic Society Research Statement

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.

Improved cookstoves to reduce household air pollution exposure in sub-Saharan Africa: A scoping review of intervention studies

Household air pollution (HAP), primarily from biomass fuels used for cooking, is associated with adverse health outcomes and premature mortality. It affects almost half of the world's population, especially in low-income and low-resourced communities. However, many of the 'improved' biomass cookstoves (ICS) aimed at reducing HAP lack empirical evidence of pollutant reduction and reliability in the field. A scoping review guided by the Joanna Briggs Institute framework was systematically conducted to explore and analyse the characteristics of cookstoves to assess the ICS available to meet the socio-economic and health needs of households in sub-Sahara Africa (sSA). The review searched Scopus, PubMed, Web of Science, EMBASE, Global Health Database on OVID, BASE, and conducted a grey literature search from 2014 to 2022 for all field-based ICS studies. In addition, user perspectives were explored for cookstoves analysed as available, affordable, and effective in reducing harmful biomass emissions. The search returned 1984 records. Thirty-three references containing 23 ICS brands were included. The cookstoves were analysed into seven categories: (1) efficiency in HAP reduction, (2) availability, (3) affordability, (4) sustainability, (5) safety, (6) health outcomes, and (7) user experience. Most (86.9%) of the improved cookstoves showed a reduction in harmful emission levels compared to the traditional three-stone fire. However, the levels were higher than the WHO-recommended safe levels. Only nine were priced below 40 USD. Users placed emphasis on cookstoves' suitability for cooking, fuel and time savings, safety, and price. Equality in cooking-related gender roles and psychosocial benefits were also reported. The review demonstrated limited field testing, a lack of evidence of ICS emissions in real-life settings in sSA, heterogeneity in emission measurements, and incomplete descriptions of ICS and kitchen features. Gender differences in exposure and psychosocial benefits were also reported. The review recommends improved cookstove promotion alongside additional measures to reduce HAP at a cost affordable to low-resource households. Future research should focus on detailed reporting of study parameters to facilitate effective comparison of ICS performance in different social settings with different local foods and fuel types. Finally, a more community-based approach is needed to assess and ensure user voices are represented in HAP intervention studies, including designing the cookstoves.

Occurrence of drug-resistant enteric bacteria and associated factors among food handlers of the Mass Catering Center: A laboratory-based cross-sectional study

This study aimed to determine antimicrobial- resistance (AMR) enteric bacterial load and associated factors among Food Handlers (FHs) ofMass Catering Center (MCC), Ethiopia. From January to June 2020, a laboratory-based cross-sectional study was conducted using the standard Swab microbiological analysis method and the Kirby-Bauer disc diffusion method on 160 randomly selected FHs and food serving areas and analyzed with RStudio- 1.2.5033 for contamination, resistance level, and source determination. The contamination of AMR Escherichia coli was33.3% (95% CI, 31.5%, 36.4%), Salmonella 30% (95% CI, 29.8%, 36.0%) and Shigella 20% (95% CI, 19.2%, 26.9%) among the hand of FHs serving in MCC. The contamination was more likely associated with low work experience [AOR, 1.42 (95% CI: 1.22-1.87)], a low educational level [AOR, 1.62 (95% CI: 1.52-189)], irrational drug use characteristics [AOR, 1.75(95% CI: 1.64-2.00)], lack of sufficient food safety knowledge [AOR, 1.52 (95% CI: 1.32-1, 67)] of the FHs and the sanitary condition of the food serving area [AOR:1.98 (95% CI, 1.45, 2.53)]. The contamination of the hand of FHs serving in the MCC with AMR enteric FBB at the University cafeteria could indicate the likelihood of the occurrence of foodborne outbreaks.

Household Air Pollution and Blood Pressure, Vascular Damage, and Subclinical Indicators of Cardiovascular Disease in Older Chinese Adults

BACKGROUND

Limited data suggest that household air pollution from cooking and heating with solid fuel (i.e., coal and biomass) stoves may contribute to the development of hypertension and vascular damage.

METHODS

Using mixed-effects regression models, we investigated the associations of household air pollution with blood pressure (BP) and vascular function in 753 adults (ages 40-79 years) from 3 diverse provinces in China. We conducted repeated measures of participants' household fuel use, personal exposure to fine particulate air pollution (PM2.5), BP, brachial-femoral pulse wave velocity (bfPWV), and augmentation index. Ultrasound images of the carotid arteries were obtained to assess intima-media thickness (CIMT) and plaques. Covariate information on sociodemographics, health behaviors, 24-h urinary sodium, and blood lipids was also obtained.

RESULTS

Average estimated yearly personal exposure to PM2.5 was 97.5 µg/m3 (SD: 79.2; range: 3.5-1241), and 65% of participants cooked with solid fuel. In multivariable models, current solid fuel use was associated with higher systolic (2.4 mm Hg, 95% CI: -0.4, 4.9) and diastolic BP (1.4 mm Hg, 95% CI: -0.1, 3.0) and greater total area of plaques (1.7 mm2, 95% CI: -6.5, 9.8) compared with exclusive use of electricity or gas stoves. A 1 - ln(µg/m3) increase in PM2.5 exposure was associated with higher systolic (1.5 mm Hg, 95% CI: 0.2, 2.7) and diastolic BP (1.0 mm Hg, 95% CI: 0.4, 1.7) and with greater CIMT (0.02 mm, 95% CI: 0.00, 0.04) and total area of plaques (4.7 mm2, 95% CI: -2.0, 11.5). We did not find associations with arterial stiffness, except for a lower bfPWV (-1.5 m/s, 95% CI: -3.0, -0.0) among users of solid fuel heaters.

CONCLUSIONS

These findings add to limited evidence that household air pollution is associated with higher BP and with greater CIMT and total plaque area.

Climate Solutions Double as Health Interventions

The climate crisis threatens to exacerbate numerous climate-sensitive health risks, including heatwave mortality, malnutrition from reduced crop yields, water- and vector-borne infectious diseases, and respiratory illness from smog, ozone, allergenic pollen, and wildfires. Recent reports from the Intergovernmental Panel on Climate Change stress the urgent need for action to mitigate climate change, underscoring the need for more scientific assessment of the benefits of climate action for health and wellbeing. Project Drawdown has analyzed more than 80 solutions to address climate change, building on existing technologies and practices, that could be scaled to collectively limit warming to between 1.5° and 2 °C above preindustrial levels. The solutions span nine major sectors and are aggregated into three groups: reducing the sources of emissions, maintaining and enhancing carbon sinks, and addressing social inequities. Here we present an overview of how climate solutions in these three areas can benefit human health through improved air quality, increased physical activity, healthier diets, reduced risk of infectious disease, and improved sexual and reproductive health, and universal education. We find that the health benefits of a low-carbon society are more substantial and more numerous than previously realized and should be central to policies addressing climate change. Much of the existing literature focuses on health effects in high-income countries, however, and more research is needed on health and equity implications of climate solutions, especially in the Global South. We conclude that adding the myriad health benefits across multiple climate change solutions can likely add impetus to move climate policies faster and further.

Do improved biomass cookstove interventions improve indoor air quality and blood pressure? A systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis evaluates the most recent evidence to examine whether use of improved biomass cookstoves in households in low-middle income countries results in reduction in mean concentrations of carbon monoxide (CO) and particulate matter of size 2.5 μm (PM_2.5) in the cooking area, as well as reduction in mean systolic (SBP) and diastolic blood pressure (DBP) of adults using the cookstoves when compared to adults who use traditional three stone fire or traditional biomass cookstoves.

METHODS

We searched databases of scientific and grey literature. We included studies if published between January 2012 and June 2021, reported impact of ICS interventions in non-pregnant adults in low/middle-income countries, and reported post-intervention results along with baseline of traditional cookstoves. Outcomes included 24- or 48-h averages of kitchen area PM_2.5, CO, mean SBP and DBP. Meta-analyses estimated weighted mean differences between baseline and post-intervention values for all outcome measures.

RESULTS

Eleven studies were included; ten contributed estimates for HAP and four for BP. Interventions lead to significant reductions in PM_2.5 (-0.73 mg/m³, 95% CI: -1.33, -0.13), CO (-8.37 ppm, 95%CI: -13.20, -3.54) and SBP (-2.82 mmHg, 95% CI: -5.53, -0.11); and a non-significant reduction in DBP (-0.80 mmHg, 95%CI: -2.33, 0.73), when compared to baseline of traditional cookstoves. Except for DBP, greatest reductions in all outcomes came from standard combustion ICS with a chimney, compared to ICS without a chimney and advanced combustion ICS.

CONCLUSION

Among the reviewed biomass stove types, ICS with a chimney feature resulted in greatest reductions in HAP and BP.

Mobile health interventions for HIV/STI prevention among youth in low- and middle-income countries (LMICs): a systematic review of studies reporting implementation outcomes

BACKGROUND

Advances and proliferation of technologies such as mobile phones may provide opportunities to improve access to HIV/STI services and reach young people with high risk for HIV and STI. However, the reach, uptake, and sustainability of mobile health (mHealth) HIV/STI interventions targeting young people aged 10-24 years in low- and middle-income countries (LMICs) are largely unknown. To address this gap and to inform implementation science research, a review was conducted to summarize what is known, and what we need to know about implementing mhealth interventions for HIV/STI prevention targeting young people in LMICs.

METHODS

We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for this review. Drawing upon Proctor's eight implementation outcome measures, we evaluated the acceptability, adoption, appropriateness, cost, feasibility, fidelity, penetration, and sustainability of  m-health HIV/STI interventions targeting young people in LMICs. The search was performed from September 2020-January 2021 and updated on March 1, 2021, in Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, SCOPUS, Global Health, and Web of Science. Eligible studies were required to include an HIV/STI prevention outcome, target young people aged 10-24 years, include a comparison/control group, and reporting of atleast one implementation outcome as outlined by Proctor.

RESULTS

A total of 1386 articles were located, and their titles and abstracts were screened. Of these, 57 full-text articles were reviewed and subsequently, and 11 articles representing 6 unique interventions were included in the systematic review. Acceptability 6 (100%), appropriateness 6 (100%), and feasibility 5(83%) were the most frequently evaluated implementation outcomes. Adoption 2 (33%), fidelity 1 (17%), and cost 1 (17%) were rarely reported; penetration and sustainability were not reported.

CONCLUSIONS

This review contributes to implementation science literature by synthesizing key implementation outcomes of mHealth HIV/STI interventions targeting young people in LMICs. Future research is needed on m-health HIV/STI implementation outcomes, particularly the penetration, cost, and long-term sustainability of these interventions. Doing so will enhance the field's understanding of the mechanisms by which these interventions lead or do not lead to changes in high HIV/STI risk and vulnerability among young people in LMICs.

Which Biomass Stove(s) Capable of Reducing Household Air Pollution Are Available to the Poorest Communities Globally?

Globally, household and ambient air pollution (HAAP) leads to approximately seven million premature deaths per year. One of the main sources of household air pollution (HAP) is the traditional stove. So-called improved cookstoves (ICS) do not reduce emissions to levels that benefit health, but the poorest communities are unlikely to have access to cleaner cooking in the medium term. Therefore, ICS are being promoted as an intermediate step. This paper summarises the current evidence on the ICS available to the global poorest, utilising data from the Clean Cookstoves Catalog and systematic review evidence from the field. The cheapest stoves offer little reduction in HAP. Only one ICS, available at US$5 or less, (the canarumwe) minimally reduced pollutants based on ISO testing standards and no studies included in the systematic reviews reported tested this stove in the field. We recommend field testing all ICS as standard, and clear information on stove characteristics, sustainability, safety, emissions efficiency, in-field performance, affordability, availability in different settings, and the ability of the stove to meet community cooking needs. In addition, ICS should be promoted alongside a suite of measures, including improved ventilation and facilities to dry wood, to further reduce the pollutant levels.

The effect of clean cooking interventions on mother and child personal exposure to air pollution: results from the Ghana Randomized Air Pollution and Health Study (GRAPHS)

BACKGROUND

Clean cooking interventions to reduce air pollution exposure from burning biomass for daily cooking and heating needs have the potential to reduce a large burden of disease globally.

OBJECTIVE

The objective of this study is to evaluate the air pollution exposure impacts of a fan-assisted efficient biomass-burning cookstove and a liquefied petroleum gas (LPG) stove intervention in rural Ghana.

METHODS

We randomized 1414 households in rural Ghana with pregnant mothers into a control arm (N = 526) or one of two clean cooking intervention arms: a fan-assisted efficient biomass-burning cookstove (N = 527) or an LPG stove and cylinder refills as needed (N = 361). We monitored personal maternal carbon monoxide (CO) at baseline and six times after intervention and fine particulate matter (PM_2.5) exposure twice after intervention. Children received three CO exposure monitoring sessions.

RESULTS

We obtained 5655 48-h maternal CO exposure estimates and 1903 for children, as well as 1379 maternal PM_2.5 exposure estimates. Median baseline CO exposures in the control, improved biomass, and LPG arms were 1.17, 1.17, and 1.30 ppm, respectively. Based on a differences-in-differences approach, the LPG arm showed a 47% reduction (95% confidence interval: 34-57%) in mean 48-h CO exposure compared to the control arm. Mean maternal PM_2.5 exposure in the LPG arm was 32% lower than the control arm during the post-intervention period (52 ± 29 vs. 77 ± 44 μg/m³). The biomass stove did not meaningfully reduce CO or PM_2.5 exposure.

CONCLUSIONS

We show that LPG interventions lowered air pollution exposure significantly compared to three-stone fires. However, post-intervention exposures still exceeded health-relevant targets.

SIGNIFICANCE

In a large controlled trial of cleaner cooking interventions, an LPG stove and fuel intervention reduced air pollution exposure in a vulnerable population in a low-resource setting.

The effect of clean cooking interventions on mother and child personal exposure to air pollution: results from the Ghana Randomized Air Pollution and Health Study (GRAPHS)

BACKGROUND

Clean cooking interventions to reduce air pollution exposure from burning biomass for daily cooking and heating needs have the potential to reduce a large burden of disease globally.

OBJECTIVE

The objective of this study is to evaluate the air pollution exposure impacts of a fan-assisted efficient biomass-burning cookstove and a liquefied petroleum gas (LPG) stove intervention in rural Ghana.

METHODS

We randomized 1414 households in rural Ghana with pregnant mothers into a control arm (N = 526) or one of two clean cooking intervention arms: a fan-assisted efficient biomass-burning cookstove (N = 527) or an LPG stove and cylinder refills as needed (N = 361). We monitored personal maternal carbon monoxide (CO) at baseline and six times after intervention and fine particulate matter (PM2.5) exposure twice after intervention. Children received three CO exposure monitoring sessions.

RESULTS

We obtained 5655 48-h maternal CO exposure estimates and 1903 for children, as well as 1379 maternal PM2.5 exposure estimates. Median baseline CO exposures in the control, improved biomass, and LPG arms were 1.17, 1.17, and 1.30 ppm, respectively. Based on a differences-in-differences approach, the LPG arm showed a 47% reduction (95% confidence interval: 34-57%) in mean 48-h CO exposure compared to the control arm. Mean maternal PM2.5 exposure in the LPG arm was 32% lower than the control arm during the post-intervention period (52 ± 29 vs. 77 ± 44 μg/m3). The biomass stove did not meaningfully reduce CO or PM2.5 exposure.

CONCLUSIONS

We show that LPG interventions lowered air pollution exposure significantly compared to three-stone fires. However, post-intervention exposures still exceeded health-relevant targets.

SIGNIFICANCE

In a large controlled trial of cleaner cooking interventions, an LPG stove and fuel intervention reduced air pollution exposure in a vulnerable population in a low-resource setting.

Effectiveness of interventions to reduce household air pollution from solid biomass fuels and improve maternal and child health outcomes in low- and middle-income countries: a systematic review protocol

BACKGROUND

A variety of public health interventions have been undertaken in low- and middle-income countries (LMICs) to prevent morbidity and mortality associated with household air pollution (HAP) due to cooking, heating and lighting with solid biomass fuels. Pregnant women and children under five are particularly vulnerable to the effects of HAP, due to biological susceptibility and typically higher exposure levels. However, the relative health benefits of interventions to reduce HAP exposure among these groups remain unclear. This systematic review aims to assess, among pregnant women, infants and children (under 5 years) in LMIC settings, the effectiveness of interventions which aim to reduce household air pollutant emissions due to household solid biomass fuel combustion, compared to usual cooking practices, in terms of health outcomes associated with HAP exposure.

METHODS

This protocol follows standard systematic review processes and abides by the PRISMA-P reporting guidelines. Searches will be undertaken in MEDLINE, EMBASE, CENTRAL, WHO International Clinical Trials Registry Platform (ICTRP), The Global Index Medicus (GIM), ClinicalTrials.gov and Greenfile, combining terms for pregnant women and children with interventions or policy approaches to reduce HAP from biomass fuels or HAP terms and LMIC countries. Included studies will be those reporting (i) pregnant women and children under 5 years; (ii) fuel transition, structural, educational or policy interventions; and (iii) health events associated with HAP exposure which occur among pregnant women or among children within the perinatal period, infancy and up to 5 years of age. A narrative synthesis will be undertaken for each population-intervention-outcome triad stratified by study design. Clinical and methodological homogeneity within each triad will be used to determine the feasibility for undertaking meta-analyses to give a summary estimate of the effect for each outcome.

DISCUSSION

This systematic review will identify the effectiveness of existing HAP intervention measures in LMIC contexts, with discussion on the context of implementation and adoption, and summarise current literature of relevance to maternal and child health. This assessment reflects the need for HAP interventions which achieve measurable health benefits, which would need to be supported by policies that are socially and economically acceptable in LMIC settings worldwide.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020164998.

Factors critical to implementation success of cleaner cooking interventions in low-income and middle-income countries: protocol for an umbrella review

INTRODUCTION

Over a third of the world's population relies on solid fuels as their primary energy source. These fuels have damaging effects on health, air quality and forest resources. Interventions to promote access to cleaner solid fuel cookstoves and clean fuels have existed for decades. However, the adoption by local communities has largely failed, which led to a waste of resources and suboptimal outcomes. Therefore, the objective of this umbrella review is to identify factors that determine implementation success for cleaner cooking interventions in low-resource settings and weigh their level of confidence in the evidence.

METHODS AND ANALYSIS

We identified systematic and narrative reviews examining factors that influence the acquisition, initial adoption or sustained use of cleaner solid fuel cookstoves and clean fuels at any scale by a literature search in PubMed, Embase, Global Health Database, Cochrane, PsycINFO, Emcare, Web of Science and CINAHL, without date or language restrictions. The search was conducted on 23 October 2017 and updated on 10 July 2019. Reviews based on qualitative, quantitative or mixed-methods studies were included and will be appraised using the Meta Quality Appraisal Tool combined with the Assessment of Multiple Systematic Reviews. Data will be extracted and factors affecting implementation will be coded using the Consolidated Framework for Implementation Research. The Grading of Recommendations Assessment, Development and Evaluation-Confidence in the Evidence from Reviews of Qualitative Research tool will be used to determine the level of confidence in the coded factors. Two researchers will independently conduct these steps.

ETHICS AND DISSEMINATION

This umbrella review does not require the approval of an ethical review board. Study results will be published in an international peer-reviewed journal. The outcomes will be converted into two practical tools: one for cleaner solid fuel cookstoves and one for clean fuels. These tools can guide the development of evidence-based implementation strategies for cleaner cooking interventions in low-income and middle-income countries to improve implementation success. These tools should be pilot-tested and promoted among regional and global initiatives.

PROSPERO REGISTRATION NUMBER

CRD42018088687.

Household and personal air pollution exposure measurements from 120 communities in eight countries: results from the PURE-AIR study

BACKGROUND

Approximately 2·8 billion people are exposed to household air pollution from cooking with polluting fuels. Few monitoring studies have systematically measured health-damaging air pollutant (ie, fine particulate matter [PM2·5] and black carbon) concentrations from a wide range of cooking fuels across diverse populations. This multinational study aimed to assess the magnitude of kitchen concentrations and personal exposures to PM2·5 and black carbon in rural communities with a wide range of cooking environments.

METHODS

As part of the Prospective Urban and Rural Epidemiological (PURE) cohort, the PURE-AIR study was done in 120 rural communities in eight countries (Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania, and Zimbabwe). Data were collected from 2541 households and from 998 individuals (442 men and 556 women). Gravimetric (or filter-based) 48 h kitchen and personal PM2·5 measurements were collected. Light absorbance (10-5m-1) of the PM2·5 filters, a proxy for black carbon concentrations, was calculated via an image-based reflectance method. Surveys of household characteristics and cooking patterns were collected before and after the 48 h monitoring period.

FINDINGS

Monitoring of household air pollution for the PURE-AIR study was done from June, 2017, to September, 2019. A mean PM2·5 kitchen concentration gradient emerged across primary cooking fuels: gas (45 μg/m3 [95% CI 43-48]), electricity (53 μg/m3 [47-60]), coal (68 μg/m3 [61-77]), charcoal (92 μg/m3 [58-146]), agricultural or crop waste (106 μg/m3 [91-125]), wood (109 μg/m3 [102-118]), animal dung (224 μg/m3 [197-254]), and shrubs or grass (276 μg/m3 [223-342]). Among households cooking primarily with wood, average PM2·5 concentrations varied ten-fold (range: 40-380 μg/m3). Fuel stacking was prevalent (981 [39%] of 2541 households); using wood as a primary cooking fuel with clean secondary cooking fuels (eg, gas) was associated with 50% lower PM2·5 and black carbon concentrations than using only wood as a primary cooking fuel. Similar average PM2·5 personal exposures between women (67 μg/m3 [95% CI 62-72]) and men (62 [58-67]) were observed. Nearly equivalent average personal exposure to kitchen exposure ratios were observed for PM2·5 (0·79 [95% 0·71-0·88] for men and 0·82 [0·74-0·91] for women) and black carbon (0·64 [0·45-0·92] for men and 0·68 [0·46-1·02] for women).

INTERPRETATION

Using clean primary fuels substantially lowers kitchen PM2·5 concentrations. Importantly, average kitchen and personal PM2·5 measurements for all primary fuel types exceeded WHO's Interim Target-1 (35 μg/m3 annual average), highlighting the need for comprehensive pollution mitigation strategies.

FUNDING

Canadian Institutes for Health Research, National Institutes of Health.

Health effects of household air pollution related to biomass cook stoves in resource limited countries and its mitigation by improved cookstoves

BACKGROUND

Household air pollution (HAP) related to cooking is associated with significant global morbidity and mortality. An estimated three billion people worldwide are exposed to cooking related HAP caused by solid fuel combustion. This exposure is highest for the vulnerable population of women and children resulting in significant cumulative health effects.

METHODS

A literature review was conducted for health effects of household air pollution related to biomass cookstoves in resource limited countries and to evaluate the effect of improved cookstoves on these health effects. We searched PubMed, Embase and Cochrane Library. We conducted searches in January 2018 with a repeat in February 2020. We included only studies conducted in resource limited countries, published in English, irrespective of publication year and studies that examined the health effects of HAP and/or studied the effects of improved cookstove (IC). Two authors independently screened journal article titles, abstracts and full-text articles to identify those that included the following search term: biomass cookstoves and health risks. We also assessed the limitations of IC with barriers to their uptake.

RESULTS

Health effects associated with HAP mostly include increased blood pressure (BP), dyspnea, childhood pneumonia, lung cancer, low birthweight and cardiovascular diseases. Being a global problem with divergent environmental factors including wide variety of fuel used, housing condition, foods prepared, climatic condition and social factors; most solutions though efficient seems inadequate. Improved cookstove (IC) mitigates emissions and improves short term health, though few randomized long-term studies could substantiate its long-standing continuance and health benefits.

CONCLUSION

There is ample data about the health effects of HAP, with some benefit with IC intervention for elevated blood pressure, dyspnea symptoms, mutagenicity and cardiovascular diseases. IC does not have any benefit in pregnancy outcomes or children health.

The role of cities in reducing the cardiovascular impacts of environmental pollution in low- and middle-income countries

BACKGROUND

As low- and middle-income countries urbanize and industrialize, they must also cope with pollution emitted from diverse sources.

MAIN TEXT

Strong and consistent evidence associates exposure to air pollution and lead with increased risk of cardiovascular disease occurrence and death. Further, increasing evidence, mostly from high-income countries, indicates that exposure to noise and to both high and low temperatures may also increase cardiovascular risk. There is considerably less research on the cardiovascular impacts of environmental conditions in low- and middle-income countries (LMICs), where the levels of pollution are often higher and the types and sources of pollution markedly different from those in higher-income settings. However, as such evidence gathers, actions to reduce exposures to pollution in low- and middle-income countries are warranted, not least because such exposures are very high. Cities, where pollution, populations, and other cardiovascular risk factors are most concentrated, may be best suited to reduce the cardiovascular burden in LMICs by applying environmental standards and policies to mitigate pollution and by implementing interventions that target the most vulnerable. The physical environment of cities can be improved though municipal processes, including infrastructure development, energy and transportation planning, and public health actions. Local regulations can incentivize or inhibit the polluting behaviors of industries and individuals. Environmental monitoring can be combined with public health warning systems and publicly available exposure maps to inform residents of environmental hazards and encourage the adoption of pollution-avoiding behaviors. Targeted individual or neighborhood interventions that identify and treat high-risk populations (e.g., lead mitigation, portable air cleaners, and preventative medications) can also be leveraged in the very near term. Research will play a key role in evaluating whether these approaches achieve their intended benefits, and whether these benefits reach the most vulnerable.

CONCLUSION

Cities in LMICs can play a defining role in global health and cardiovascular disease prevention in the next several decades, as they are well poised to develop innovative, multisectoral approaches to pollution mitigation, while also protecting the most vulnerable.