A follow-up study after an improved cookstove intervention in rural Mexico: Estimation of household energy use and chronic PM2.5 exposure

Effect of a chimney-fitted improved stove on pregnancy outcomes in Northwest Ethiopia: a randomized controlled trial

BACKGROUND

Exposure to household air pollution during pregnancy has been linked to adverse pregnancy outcomes. Improved stove was implemented in Ethiopia to reduce this exposure and related health problems. However, the effects of improved stove interventions on pregnancy outcomes remains uncertain.

METHOD

Individually randomized stove replacement trial was conducted among 422 households in six low-income rural kebeles of Northwestern Ethiopia. Pregnant women without known health conditions were recruited at ≤ 24 weeks gestation and randomized to an intervention or control group with a 1:1 ratio. A baseline survey was collected and a balance test was done. Two-sided independent samples t-test for continuous outcomes and chi-square for categorical variables were used to compare the effect of the intervention between the groups. Mean differences with 95% CIs were calculated and a p-value of < 0.05 was considered statistically significant.

RESULT

In this study, the mean birth weight was 3065 g (SD = 453) among the intervention group and not statistically different from 2995 g (SD = 541) of control group. After adjusting for covariates, infants born from intervention group weighed 55 g more [95% CI: - 43 to 170) than infants born from the control group, but the difference was not statistically significant (P = 0.274). The respective percentages for low birth weight were 8% and 10.3% for intervention and control groups respectively (P = 0.346). However, the average gestational age at delivery was higher among improved stove users (38 weeks (SD = 8.2) compared to control groups 36.5 weeks (SD = 9.6) with statistically significant difference at 0.91 weeks (95% CI: 0.52 to 1.30 weeks, p < 0.001). The corresponding difference in risk ratio for preterm birth is 0.94 (95% CI:0.92 to 0.97; p < 0.001). The percentages for maternal complications, stillbirth, and miscarriage in the intervention group were not statistically different from the control group.

CONCLUSIONS

While the increase in average birth weight among babies born to mothers using improved stoves was not statistically significant, babies had a longer gestational age on average, offering valuable health benefits. However, the study didn't find a significant impact on other pregnancy outcomes like stillbirth, miscarriage, or maternal complications.

TRIAL REGISTRATION

The study was registered at the Pan African Clinical Trial Registry website under the code PACTR202111534227089, ( https://pactr.samrc.ac.za/ (Identifier). The first trial registration date was (11/11/2021).

Socioeconomic and Environmental Aspects of Traditional Firewood for Cooking on the Example of Rural and Peri-Urban Mexican Households

Firewood is a solid biofuel that is widely used for cooking in Mexico’s residential sector. This study seeks to identify relevant factors in firewood consumption patterns, and their implications for climate change, gender, and health, and for energy poverty in Mexico, by climate region and socioeconomic level. For this purpose, a statistical analysis was conducted of recently published official information. We estimate that a total of 31.3 million Mexicans—26% of the total population—use firewood, and we have identified three main types of users: (i) exclusive firewood users (30%); (ii) mixed firewood users using firewood as their primary fuel (18%) and (iii) mixed firewood users using firewood as their secondary fuel source (52%). Total consumption of firewood was estimated at 116.6 PJ, while estimated greenhouse gas emissions were 8.1 million tCO2e. Out of all the households studied, 53% were in the tropical climate region; 59% were categorized as being in the “low” socioeconomic level; and 75% were in population centers comprising fewer than 2500 inhabitants. Some 68% of households do not pay for the acquisition of firewood, and for those households that do pay for the resource, estimated transactions total USD 286.9 million. Expenditures on firewood for energy represent up to 10% of household income. Finally, it was estimated that 15.7 million direct users of firewood are women who use the resource in three-stone fires, in which they expose themselves to health risks in doing so. In conclusion, main universal findings, the study’s limitations, and future research are presented.

"We threw away the stones": a mixed method evaluation of a simple cookstove intervention in Malawi

Background: Air pollution exposure is responsible for a substantial burden of respiratory disease globally. Household air pollution from cooking using biomass is a major contributor to overall exposure in rural low-income settings. Previous research in Malawi has revealed how precarity and food insecurity shape individuals' daily experiences, contributing to perceptions of health. Aiming to avoid a mismatch between research intervention and local context, we introduced a simple cookstove intervention in rural Malawi, analysing change in fine particulate matter (PM 2.5) exposures, and community perceptions. Methods: Following a period of baseline ethnographic research, we distributed 'chitetezo mbaula', locally-made cookstoves, to all households (n=300) in a rural Malawian village. Evaluation incorporated village-wide participant observation and concurrent exposure monitoring using portable PM 2.5 monitors at baseline and follow-up (three months post-intervention). Qualitative data were thematically analysed. Quantitative analysis of exposure data included pre-post intervention comparisons, with datapoints divided into periods of combustion activity (almost exclusively cooking) and non-combustion periods. Findings were integrated at the interpretation stage, using a convergent design mode of synthesis. Results: Individual exposure monitoring pre- and post-cookstove intervention involved a sample of 18 participants (15 female; mean age 43). Post-intervention PM 2.5 exposures (median 9.9μg/m 3 [interquartile range: 2.2-46.5]) were not significantly different to pre-intervention (11.8μg/m 3 [3.8-44.4]); p=0.71. On analysis by activity, background exposures were found to be reduced post-intervention (from 8.2μg/m 3 [2.5-22.0] to 4.6μg/m 3 [1.0-12.6]; p=0.01). Stoves were well-liked and widely used by residents as substitutes for previous cooking methods (mainly three-stone fires). Commonly cited benefits related to fuel saving and shorter cooking times. Conclusions: The cookstove intervention had no impact on cooking-related PM 2.5 exposures. A significant reduction in background exposures may relate to reduced smouldering emissions. Uptake and continued use of the stoves was high amongst community members, who preferred using the stoves to cooking over open fires.

Factors affecting access to clean cooking fuel among rural households in India during COVID-19 pandemic

This paper investigates the factors affecting access to clean cooking fuel among rural Indian households during the COVID-19 outbreak, based on World Bank's rural impact survey, covering 2731 rural households. Our analysis shows a significant decline in access to clean fuel among rural households from 35% in 2018 i.e. before COVID-19 to 19.7% during the COVID-19 pandemic. This implies that in order to meet their cooking needs, many rural households have switched from conventional fuels, which have numerous health and environmental concerns. The association between states and socio-demographic profiles of rural households with access to sources of cooking fuel shows a significant difference. The analysis results further indicate that socio-demographic characteristics and asset holdings of the rural households are the key factors that determine access to clean cooking fuel during COVID-19. Among the socio-demographic variables, age, gender, family size, social category, and income level are estimated to be significant factors that affect the access to clean fuel for cooking. Similarly, ownership of assets such as exclusive kitchen room, refrigerator, pressure cooker, television, and furniture are significant factors affecting access to clean cooking fuel among Indian rural households. Additionally, this study provides policy insights on developing mechanisms to ensure that rural households have an access to clean cooking fuel during crisis situations such as COVID-19.

"We threw away the stones": a mixed method evaluation of a simple cookstove intervention in Malawi

Background: Air pollution exposure is responsible for a substantial burden of respiratory disease globally. Household air pollution from cooking using biomass is a major contributor to overall exposure in rural low-income settings. Previous research in Malawi has revealed how precarity and food insecurity shape individuals' daily experiences, contributing to perceptions of health. Aiming to avoid a mismatch between research intervention and local context, we introduced a simple cookstove intervention in rural Malawi, analysing change in fine particulate matter (PM 2.5) exposures, and community perceptions. Methods: Following a period of baseline ethnographic research, we distributed 'chitetezo mbaula', locally-made cookstoves, to all households (n=300) in a rural Malawian village. Evaluation incorporated village-wide participant observation and concurrent exposure monitoring using portable PM 2.5 monitors at baseline and follow-up (three months post-intervention). Qualitative data were thematically analysed. Quantitative analysis of exposure data included pre-post intervention comparisons, with datapoints divided into periods of combustion activity (almost exclusively cooking) and non-combustion periods. Findings were integrated at the interpretation stage, using a convergent design mode of synthesis. Results: Individual exposure monitoring pre- and post-cookstove intervention involved a sample of 18 participants (15 female; mean age 43). Post-intervention PM 2.5 exposures (median 9.9μg/m 3 [interquartile range: 2.2-46.5]) were not significantly different to pre-intervention (11.8μg/m 3 [3.8-44.4]); p=0.71. On analysis by activity, background exposures were found to be reduced post-intervention (from 8.2μg/m 3 [2.5-22.0] to 4.6μg/m 3 [1.0-12.6]; p=0.01). Stoves were well-liked and widely used by residents as substitutes for previous cooking methods (mainly three-stone fires). Commonly cited benefits related to fuel saving and shorter cooking times. Conclusions: The cookstove intervention had no impact on cooking-related PM 2.5 exposures. A significant reduction in background exposures may relate to reduced smouldering emissions. Uptake and continued use of the stoves was high amongst community members, who preferred using the stoves to cooking over open fires.

"We threw away the stones": a mixed method evaluation of a simple cookstove intervention in Malawi

Background: Exposure to air pollution is responsible for a substantial burden of respiratory disease globally. Household air pollution from cooking using biomass is a major contributor to overall exposure in rural low-income settings. Previous research in Malawi has revealed how precarity and food insecurity shape individuals' daily experiences, contributing to perceptions of health. Aiming to avoid a mismatch between research intervention and local context, we introduced a simple cookstove intervention in rural Malawi, analysing change in fine particulate matter (PM 2.5) exposures, and community perceptions. Methods: Following a period of baseline ethnographic research, we distributed 'chitetezo mbaula', locally made clay cookstoves, to all households (n=300) in a rural Malawian village. Evaluation incorporated village-wide participant observation and concurrent exposure monitoring using portable PM 2.5 monitors at baseline and follow-up (three months post-intervention). Qualitative data were thematically analysed. Quantitative analysis of exposure data included pre-post intervention comparisons, with datapoints divided into cooking and non-cooking ('baseline') periods. Findings were integrated at the interpretation stage, using a convergent design mode of synthesis. Results: Individual exposure monitoring pre- and post-cookstove intervention  involved a sample of 18 participants (15 female; mean age 43). Post-intervention PM 2.5 exposures (median 9.9μg/m 3 [interquartile range: 2.2-46.5]) were not significantly different to pre-intervention (11.8μg/m 3 [3.8-44.4]); p=0.71. On analysis by activity, 'baseline' exposures were found to be reduced post-intervention (from 8.2μg/m 3 [2.5-22.0] to 4.6μg/m 3 [1.0-12.6]; p=0.01). Stoves were well-liked and widely used by residents as substitutes for previous cooking methods (mainly three-stone fires). Most cited benefits related to fuel saving and shorter cooking times. Conclusions: The cookstove intervention had no impact on cooking-related PM 2.5 exposures. A significant reduction in baseline exposures may relate to reduced smouldering emissions. Uptake and continued use of the stoves was high amongst community members, who preferred using the stoves to cooking over open fires.

Using Design Thinking to Improve Cook Stoves Development in Mexico

A traditional use of bioenergy is the main source of residential energy in developing countries, essentially using firewood to cook, boil water or heating affecting people in developing countries. Improved cook stoves are more efficient and less polluting, and there is a need to evaluate different design options to facilitate their adoption. There are different types of very economical improved cookstoves with high combustion efficiency. In Mexico, multiple projects about cook stoves have been carried out, the root of this study being one of them: the Patsari cook stoves. The goal of this project was to modify previous stove designs to align with local people’s habits and traditions. This study shows the importance of including the participation of users in the design of the portable model of Patsari cook stoves, applying the Design Thinking methodology. Many designs or design changes have been carried out on cook stoves by different researchers, but users often do not adapt to them. This article, through a field study, shows the importance of integrating theoretical analyses along with user experiences to facilitate the adoption of improved cook stoves and ensure their success.

Biomass-fuelled improved cookstove intervention to prevent household air pollution in Northwest Ethiopia: a cluster randomized controlled trial

Background

Household air pollution from biomass fuels burning in traditional cookstoves currently appeared as one of the most serious threats to public health with a recent burden estimate of 2.6 million premature deaths every year worldwide, ranking highest among environmental risk factors and one of the major risk factors of any type globally. Improved cookstove interventions have been widely practiced as potential solutions. However, studies on the effect of improved cookstove interventions are limited and heterogeneous which suggested the need for further research.

Methods

A cluster randomized controlled trial study was conducted to assess the effect of biomass-fuelled improved cookstove intervention on the concentration of household air pollution compared with the continuation of an open burning traditional cookstove. A total of 36 clusters were randomly allocated to both arms at a 1:1 ratio, and improved cookstove intervention was delivered to all households allocated into the treatment arm. All households in the included clusters were biomass fuel users and relatively homogenous in terms of basic socio-demographic and cooking-related characteristics. Household air pollution was determined by measuring the concentration of indoor fine particulate, and the effect of the intervention was estimated using the Generalized Estimating Equation.

Results

A total of 2031 household was enrolled in the study across 36 randomly selected clusters in both arms, among which data were obtained from a total of 1977 households for at least one follow-up visit which establishes the intention-to-treat population dataset for analysis. The improved cookstove intervention significantly reduces the concentration of household air pollution by about 343 μg/m³ (Ḃ = − 343, 95% CI − 350, − 336) compared to the traditional cookstove method. The overall reduction was found to be about 46% from the baseline value of 859 (95% CI 837–881) to 465 (95% CI 458–472) in the intervention arm compared to only about 5% reduction from 850 (95% CI 828–872) to 805 (95% CI 794–817) in the control arm.

Conclusions

The biomass-fuelled improved cookstove intervention significantly reduces the concentration of household air pollution compared to the traditional method. This suggests that the implementation of these cookstove technologies may be necessary to achieve household air pollution exposure reductions.

Trial registration

The trial project was retrospectively registered on August 2, 2018, at the clinical trials.gov registry database (https://clinicaltrials.gov/) with the NCT03612362 registration identifier number.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12199-020-00923-z.

A neglected source of household air pollution: a preliminary, mixed methods study of purposely produced household smoke in Wollo, Ethiopia

BACKGROUND

Ill health associated with household air pollution (HAP) is increasingly recognized as a public health problem in sub-Saharan Africa. To date, attempts to reduce HAP have focussed on smoke from cooking fires and have ignored traditional cultural practices which generate purposely produced smoke (PPS). This study aimed to investigate PPS prevalence, reasons for use and safety perceptions.

METHODS

The study was conducted in Wollo, Ethiopia, and used a mixed methods approach of quantitative surveys (analysed descriptively) and qualitative interviews with householders and healthcare workers (analysed thematically).

RESULTS

PPS use was reported by 99% of survey respondents and it was considered a fundamental part of life. Although reasons for use included housekeeping, culture/religion and well-being, coffee ceremony was most commonly cited (44% of respondents). Both householders and healthcare workers appeared to assume PPS is safe, except for people with certain underlying conditions. Healthcare workers felt the lack of evidence of harm from PPS meant there was no justification for intervention.

CONCLUSION

This study, the first in-depth study of PPS, has shown its use to be widespread, with many perceived benefits and thus a very important part of local culture in this sample Ethiopian community. Consequently, any public health interventions aimed at reducing HAP in this setting need to consider PPS.

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 19.1 kg (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 0.5 kg higher for each additional pig or dog owned (p=0.003), 0.7 kg higher for each additional household member (p<0.001), 0.3 kg higher for households in the second-lowest compared to the lowest wealth quintile (p=0.01), and 1.1 kg higher if the household had previously received subsidized LPG (p=0.05). LPG use per month was 1.1 kg lower during the rainy season (p<0.001) and 1.7 kg 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 0.05 kg 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 10 kg 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.

Critical review of social, environmental and health risk factors in the Mexican indigenous population and their capacity to respond to the COVID-19

The objective of this study was to conduct a critical analysis of the social, environmental and health risk factors in the Mexican indigenous population in the context of the COVID-19 disease pandemic, and to propose strategies to mitigate the impacts on these communities. Regarding social factors, we identified the return of indigenous people to their communities, poor access to water, language barriers, and limited access to the Internet, as factors that will not allow them to take the minimum preventive measures against the disease. Additionally, environmental risk factors associated with pollutants from biomass burning were identified. In health, the lack of coverage in these areas and comorbidities such as diabetes mellitus, hypertension, respiratory tract infections, and chronic pulmonary diseases were identified. Some existing government programmes were identified that could be supported to address these social, environmental and health gaps. We believe that the best way to address these issues is to strengthen the health system with a community-based approach. Health is the best element of cohesion for inserting development and progress proposals in indigenous communities, given the vulnerability to which they are exposed in the face of the COVID-19 pandemic. In this review, all information is provided (as possible) on risk factors and potential solutions in indigenous communities in the hope of providing solutions to this pandemic and providing a reference for future studies.

Understanding Household Energy Transitions: From Evaluating Single Cookstoves to “Clean Stacking” Alternatives

The pervasiveness of “stacking” between traditional and clean fuels/stoves is moving the household clean cooking research and policy agenda from programs that are centered on one-fuel or stove, to multi-clean fuel/device interventions that could result in a more effective displacement of traditional biomass stoves. However, there is little recognition and knowledge of the benefits realistic clean-stacking cooking solutions can have on indoor air quality and health. In this paper, particulate matter (PM2.5) and carbon monoxide (CO) concentration levels that are associated with stove-stacking options (Patsari-U-shaped open fire (U-type), Patsari-liquefied petroleum gas (LPG) stove, U-type-LPG, and Patsari-U-type-LPG) common within rural Mexico were evaluated while using a controlled cooking cycle (CCC) from the Purepecha Highlands, which mimics the most common dishes prepared daily within the region as well as their sequential arrangement. The results confirms that the WHO Interim Target-1 (IT1) of 35 μg/m3 for PM2.5 is exceeded whenever woodburning open fires are part of the stacking combination (Patsari-U-type 107 ± 9 μg/m3, U-type-LPG 131 ± 55 μg/m3 and Patsari-U-type-LPG 107 ± 22 μg/m3). However, well-designed and properly operated woodburning chimney stoves, such as the Patsari can meet the IT1, either used exclusively (21 ± 8 μg/m3) or as a “clean stacking” option with LPG (24 ± 5 μg/m3). Given stove stacking patterns, evaluating the health and environmental consequences of stove transitions while assuming the total replacement of traditional fires by clean cooking options will lead to misplaced expectations, and programs should evaluate more realistic “clean-stacking” options.