Household Air Pollution Exposures of Pregnant Women Receiving Advanced Combustion Cookstoves in India: Implications for Intervention

Personal exposure to household air pollution and lung function in rural Bangladesh: A population-based cross-sectional study

We assessed whether personal exposure to household air pollution [PM2.5 and black carbon (BC)] is associated with lung functions (FEV1, FVC, and their ratio) in non-smoking adults in rural Bangladesh. We measured personal exposure to PM2.5 using gravimetric analysis of PM2.5 mass and BC by reflectance measurement between April 2016 and June 2019. The average 24-hour PM2.5 and BC concentration was 141.0μgm-3 and 13.8μgm-3 for females, and 91.7 μgm-3 and 10.1 μgm-3 for males, respectively. A 1 μgm-3 increase in PM2.5 resulted in a 0.02 ml reduction in FEV1, 0.43 ml reduction in FVC, and 0.004% reduction in FEV1/FVC. We also found a similar inverse relationship between BC and lung functions (9.6 ml decrease in FEV1 and 18.5 ml decrease in FVC per 1μgm-3 increase in BC). A higher proportion of non-smoking biomass fuel users (50.1% of the females and 46.7% of the males) had restrictive patterns of lung function abnormalities, which need further exploration.

A review and analysis of personal and ambient PM2.5 measurements: Implications for epidemiology studies

BACKGROUND

In epidemiology studies, ambient measurements of PM_2.5 are often used as surrogates for personal exposures. However, it is unclear the degree to which ambient PM_2.5 reflects personal exposures.

OBJECTIVE

In order to examine potential sources of bias in epidemiology studies, we conducted a review and meta-analysis of studies to determine the extent to which short-term measurements of ambient PM_2.5 levels are related to short-term measurements of personal PM_2.5 levels.

METHODS

We conducted a literature search of studies reporting both personal and ambient measurements of PM_2.5 published in the last 10 years (2009-2019) and incorporated studies published prior to 2009 from reviews.

RESULTS

Seventy-one studies were identified. Based on 17 studies reporting slopes, a meta-analysis revealed an overall slope of 0.56 μg/m³ (95% CI: [0.39, 0.73]) personal PM_2.5 per μg/m³ increase in ambient PM_2.5. Slopes for summer months were higher (slope = 0.73, 95% CI: [0.64, 0.81]) than for winter (slope = 0.46, 95% CI: [0.36, 0.57]). Based on 44 studies reporting correlations, we calculated an overall personal-ambient PM_2.5 correlation of 0.63 (95% CI: [0.55, 0.71]). Correlations were stronger in studies conducted in Canada (r = 0.86, 95% CI: [0.67, 0.94]) compared to the USA (r = 0.60, 95% CI: [0.49, 0.70]) and China (r = 0.60, 95% CI: [0.46, 0.71]). Correlations also were stronger in urban areas (r = 0.53, 95% CI: [0.43, 0.62]) vs. suburban areas (r = 0.36, 95% CI: [0.21, 0.49]).

SIGNIFICANCE

Our results suggest a large degree of variability in the personal-ambient PM_2.5 association and the potential for exposure misclassification and measurement error in PM_2.5 epidemiology studies.

Personal exposure to PM2.5 of indoor and outdoor origin in two neighboring Chinese communities with contrasting household fuel use patterns

The Chinese government is replacing high-polluting, household coal heating stoves with electricity- and natural gas-powered heaters to improve ambient air quality. The evaluation of the intervention impact on outdoor PM_2.5 and personal exposure in community level are in their initial stages. We compared outdoor air pollution and personal exposure in two neighboring communities (~2 km) in northern China with contrasting household fuel use patterns: one where residents primarily used coal for cooking and heating ("coal village") and one where natural gas was the dominant fuel ("gas village"). We collected 24-h outdoor gravimetric PM_2.5 samples in each village and concurrently measured 48-h integrated exposures among 71 participants from 41 and 30 households in the coal and gas villages, respectively. PM_2.5 samples were analyzed for mass and chemical composition. Daily outdoor PM_2.5 concentrations in the coal village (mean ± standard deviation: 109 ± 41 μg/m³) were, on average, 1.3 ± 0.2 times higher than in the gas village (88 ± 38 μg/m³). However, personal PM_2.5 exposures were lower in the coal village (116 ± 121 μg/m³ versus 156 ± 106 μg/m³). PM_2.5 species that can serve as tracers for residential coal combustion (e.g., S, Se, Zn, Pb, etc.) and dust (Al, Ca, Mg, Fe, Si and Ti) were higher in the coal village, and the proportion of personal PM_2.5 of outdoor origin in the coal village was nearly 2 times higher than the gas village. Our results suggest that ambient PM_2.5 and its chemical composition can vary at relatively small spatial scales and may reflect community-level differences in the household energy use. However, personal PM_2.5 exposures may not mirror between-village differences in outdoor air pollution if only PM_2.5 mass is evaluated. Individual chemical composition of PM_2.5 exposure can provide important insight in future studies on the effectiveness of source-targeted air quality interventions.

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.

High Levels of Fine Particulate Matter (PM2.5) Concentrations from Burning Solid Fuels in Rural Households of Butajira, Ethiopia

The use of solid fuel, known to emit pollutants which cause damage to human health, is the primary energy option in Ethiopia. Thus, the aim of this study was to measure the level of household air pollution by using the 24-h mean concentration of fine particulate matter (PM_2.5) in 150 randomly recruited households in rural Butajira, Ethiopia. Data relating to household and cooking practices were obtained by conducting face-to-face interviews with the mothers. The 24-h mean (standard deviation) and median PM_2.5 concentrations were 410 (220) and 340 µg/m³, respectively. Households using only traditional stoves and those who did not open the door or a window during cooking had a significantly higher mean concentration compared with their counterparts. There is a statistically significant correlation between the mean concentration of PM_2.5 and the self-reported cooking duration. The pollution level was up to 16 times higher than the WHO 24-h guideline limit of 25 μg/m^3, thus leaving the mothers and children who spend the most time at the domestic hearth at risk of the adverse health effects from solid fuel use in Ethiopia. Thus, effective short- and long-term interventions are urgently needed.

Solid fuels use for cooking and sleep health in adults aged 45 years and older in China

Outdoor air pollution has been linked to poor sleep health, but limited studies have investigated the relationship between solid cooking fuels and sleep health in adults. Therefore, we analyzed data from the China Health and Retirement Survey (CHARLS), a national survey of about 17,000 residents aged over 45. Participants were restricted to those who participated in CHARLS 2011, 2013 and 2015 (n = 8,668). Sleep health was indicated by self-reported average sleep hours at night and the numbers of unrested days/week in CHARLS 2015. We analyzed cooking fuel types reported and assessed the duration of solid fuels usage as consistent (indicated use in all three surveys or 6 + years) or inconsistent use (indicated use in one or two surveys or 1-4 years). We found consistent use of solid fuels was associated with a shorter sleep duration (OR = 1.17 95% CI 1.01, 1.35 for ≤ 6 h vs. 7-9 h/day) and higher frequencies of feeling unrested (OR = 1.32 95% CI 1.12, 1.55 for ≥ 5 days/week vs. none) compared with cleaner fuels use. The associations for inconsistent solid fuels use and sleep health were in the similar direction but smaller in magnitude. Further research is needed to confirm our findings and evaluate the exposure impact of specific fuel types to inform intervention strategies.

Exposure contrasts associated with a liquefied petroleum gas (LPG) intervention at potential field sites for the multi-country household air pollution intervention network (HAPIN) trial in India: results from pilot phase activities in rural Tamil Nadu

BACKGROUND

The Household Air Pollution Intervention Network (HAPIN) trial aims to assess health benefits of a liquefied petroleum gas (LPG) cookfuel and stove intervention among women and children across four low- and middle-income countries (LMICs). We measured exposure contrasts for women, achievable under alternative conditions of biomass or LPG cookfuel use, at potential HAPIN field sites in India, to aid in site selection for the main trial.

METHODS

We recruited participants from potential field sites within Villupuram and Nagapattinam districts in Tamil Nadu, India, that were identified during a feasibility assessment. We performed. (i) cross-sectional measurements on women (N = 79) using either biomass or LPG as their primary cookfuel and (ii) before-and-after measurements on pregnant women (N = 41), once at baseline while using biomass fuel and twice - at 1 and 2 months - after installation of an LPG stove and free fuel intervention. We involved participants to co-design clothing and instrument stands for personal and area sampling. We measured 24 or 48-h personal exposures and kitchen and ambient concentrations of fine particulate matter (PM2.5) using gravimetric samplers.

RESULTS

In the cross-sectional analysis, median (interquartile range, IQR) kitchen PM2.5 concentrations in biomass and LPG using homes were 134 μg/m3 [IQR:71-258] and 27 μg/m3 [IQR:20-47], while corresponding personal exposures were 75 μg/m3 [IQR:55-104] and 36 μg/m3 [IQR:26-46], respectively. In before-and-after analysis, median 48-h personal exposures for pregnant women were 72 μg/m3 [IQR:49-127] at baseline and 25 μg/m3 [IQR:18-35] after the LPG intervention, with a sustained reduction of 93% in mean kitchen PM2.5 concentrations and 78% in mean personal PM2.5 exposures over the 2 month intervention period. Median ambient concentrations were 23 μg/m3 [IQR:19-27). Participant feedback was critical in designing clothing and instrument stands that ensured high compliance.

CONCLUSIONS

An LPG stove and fuel intervention in the candidate HAPIN trial field sites in India was deemed suitable for achieving health-relevant exposure reductions. Ambient concentrations indicated limited contributions from other sources. Study results provide critical inputs for the HAPIN trial site selection in India, while also contributing new information on HAP exposures in relation to LPG interventions and among pregnant women in LMICs.

TRIAL REGISTRATION

ClinicalTrials.Gov. NCT02944682 ; Prospectively registered on October 17, 2016.

A hierarchical model for estimating the exposure-response curve by combining multiple studies of acute lower respiratory infections in children and household fine particulate matter air pollution

Adverse health effects of household air pollution, including acute lower respiratory infections (ALRIs), pose a major health burden around the world, particularly in settings where indoor combustion stoves are used for cooking. Individual studies have limited exposure ranges and sample sizes, while pooling studies together can improve statistical power.

Methods

We present hierarchical models for estimating long-term exposure concentrations and estimating a common exposure-response curve. The exposure concentration model combines temporally sparse, clustered longitudinal observations to estimate household-specific long-term average concentrations. The exposure-response model provides a flexible, semiparametric estimate of the exposure-response relationship while accommodating heterogeneous clustered data from multiple studies. We apply these models to three studies of fine particulate matter (PM_2.5) and ALRIs in children in Nepal: a case-control study in Bhaktapur, a stepped-wedge trial in Sarlahi, and a parallel trial in Sarlahi. For each study, we estimate household-level long-term PM_2.5 concentrations. We apply the exposure-response model separately to each study and jointly to the pooled data.

Results

The estimated long-term PM_2.5 concentrations were lower for households using electric and gas fuel sources compared with households using biomass fuel. The exposure-response curve shows an estimated ALRI odds ratio of 3.39 (95% credible interval = 1.89, 6.10) comparing PM_2.5 concentrations of 50 and 150 μg/m³ and a flattening of the curve for higher concentrations.

Conclusions

These flexible models can accommodate additional studies and be applied to other exposures and outcomes. The studies from Nepal provides evidence of a nonlinear exposure-response curve that flattens at higher concentrations.

Effectiveness of Gas and Chimney Biomass Stoves for Reducing Household Air Pollution Pregnancy Exposure in Guatemala: Sociodemographic Effect Modifiers

Household air pollution (HAP) due to solid fuel use during pregnancy is associated with adverse birth outcomes. The real-life effectiveness of clean cooking interventions has been disappointing overall yet variable, but the sociodemographic determinants are not well described. We measured personal 24-h PM_2.5 (particulate matter <2.5 µm in aerodynamic diameter) thrice in pregnant women (n = 218) gravimetrically with Teflon filter, impactor, and personal pump setups. To estimate the effectiveness of owning chimney and liquefied petroleum gas (LPG) stoves (i.e., proportion of PM_2.5 exposure that would be prevented) and to predict subject-specific typical exposures, we used linear mixed-effects models with log (PM_2.5) as dependent variable and random intercept for subject. Median (IQR) personal PM_2.5 in µg/m³ was 148 (90-249) for open fire, 78 (51-125) for chimney stove, and 55 (34-79) for LPG stoves. Adjusted effectiveness of LPG stoves was greater in women with ≥6 years of education (49% (95% CI: 34, 60)) versus <6 years (26% (95% CI: 5, 42)). In contrast, chimney stove adjusted effectiveness was greater in women with <6 years of education (50% (95% CI: 38, 60)), rural residence (46% (95% CI: 34, 55)) and lowest SES (socio-economic status) quartile (59% (95% CI: 45, 70)) than ≥6 years education (16% (95% CI: 22, 43)), urban (23% (95% CI: -164, 42)) and highest SES quartile (-44% (95% CI: -183, 27)), respectively. A minority of LPG stove owners (12%) and no chimney owner had typical exposure below World Health Organization Air Quality guidelines (35 μg/m³). Although having a cleaner stove alone typically does not lower exposure enough to protect health, understanding sociodemographic determinants of effectiveness may lead to better targeting, implementation, and adoption of interventions.

Drivers of the Adoption and Exclusive Use of Clean Fuel for Cooking in Sub-Saharan Africa: Learnings and Policy Considerations from Cameroon

Household air pollution (HAP) caused by the combustion of solid fuels for cooking and heating is responsible for almost 5% of the global burden of disease. In response, the World Health Organisation (WHO) has recommended the urgent need to scale the adoption of clean fuels, such as liquefied petroleum gas (LPG), in low and middle-income countries (LMICs). To understand the drivers of the adoption and exclusive use of LPG for cooking, we analysed representative survey data from 3343 peri-urban and rural households in Southwest Cameroon. Surveys used standardised tools to collect information on fuel use, socio-demographic and household characteristics and use of LPG for clean cooking. Most households reported LPG to be clean (95%) and efficient (88%), but many also perceived it to be expensive (69%) and unsafe (64%). Positive perceptions about LPG's safety (OR = 2.49, 95% CI = 2.04, 3.05), cooking speed (OR = 4.31, 95% CI = 2.62, 7.10), affordability (OR = 1.7, 95% CI = 1.38, 2.09), availability (OR = 2.17, 95% CI = 1.72, 2.73), and its ability to cook most dishes (OR = 3.79, 95% CI = 2.87, 5.01), were significantly associated with exclusive LPG use. Socio-economic status (higher education) and household wealth (higher income) were also associated with a greater likelihood of LPG adoption. Effective strategies to raise awareness around safe use of LPG and interventions to address financial barriers are needed to scale wider adoption and sustained use of LPG for clean cooking, displacing reliance on polluting solid fuels.

The Association of Cooking Fuel Use, Dietary Intake, and Blood Pressure among Rural Women in China

Household air pollution (HAP) from solid cooking fuels continues to affect 600 million people in China and has been associated with high blood pressure. The role of diet in HAP-associated high blood pressure has yet to be evaluated in China. The aim of this study was to estimate the impact of cooking fuel on change in blood pressure and evaluate whether intake of antioxidant- and omega-3 fatty acid-rich foods (fruits, vegetables, and seafood) attenuates any adverse effects of solid fuel use on blood pressure. We analyzed longitudinal data collected between 1991 and 2011 from nonpregnant women aged 18 to 80 years living in rural areas of China. We used linear mixed effects models to estimate the association between cooking fuel (coal or wood versus clean [electric or liquid petroleum gas]) and blood pressure. Possible mediation of the fuel effect by diet was assessed by the difference method. A total of 6671 women were included in this study. Women less than 40 years of age cooking with cleaner fuels over time had lower rates of change in systolic blood pressure compared to women cooking with coal (p = 0.004), and this effect was not mediated by dietary intake. Associations between fuel use and change in diastolic blood pressure were not significant. These findings lend further support for there being a direct effect of reducing HAP on improvements in blood pressure, independent of concurrent dietary intake.

Barriers and Facilitators to the Adoption and Sustained Use of Cleaner Fuels in Southwest Cameroon: Situating 'Lay' Knowledge within Evidence-Based Policy and Practice

Approximately four million people die each year in low- and middle-income countries from household air pollution (HAP) due to inefficient cooking with solid fuels. Liquid Petroleum Gas (LPG) offers a clean energy option in the transition towards renewable energy. This qualitative study explored lay knowledge of barriers and facilitators to scaling up clean fuels in Cameroon, informed by Quinn et al.'s Logic Model. The model has five domains and we focused on the user and community needs domain, reporting the findings of 28 semi-structured interviews (SSIs) and four focus group discussions (FGDs) that explored the reasons behind fuel use choices. The findings suggest that affordability, safety, convenience, and awareness of health issues are all important influences on decision making to the adoption and sustained use of LPG, with affordability being the most critical issue. We also found the ability of clean fuels to meet cooking needs to be central to decision-making, rather than an aspect of convenience, as the logic model suggests. Local communities provide important insights into the barriers and facilitators to using clean fuels. We adapt Quinn et al.'s logic model accordingly, giving more weight to lay knowledge so that it is better positioned to inform policy development.

Effectiveness of a Household Energy Package in Improving Indoor Air Quality and Reducing Personal Exposures in Rural China

We evaluated whether an energy package comprising a low-polluting semigasifier cookstove with chimney, water heater, and pelletized biomass fuel would improve air pollution in China. We measured the stove use, 48-h air pollution exposures (PM_2.5, black carbon), and kitchen concentrations (PM_2.5, black carbon, carbon monoxide, nitrogen oxides) for 205 women, along with ambient PM_2.5. Over half (n = 125) were offered the energy package after baseline assessment, forming "treated" and "untreated" groups, and we repeated the measurements up to 3 occasions over 18-months. Kitchen carbon monoxide did not change, and nitrogen oxides increased in summer but decreased in winter for both groups. Summer geometric mean exposures and kitchen concentrations of PM_2.5 and black carbon decreased by 24-67% in women who received the energy package, but greater reductions (48-70%) were observed in untreated homes, likely due to increased use of gas stoves. After adjusting for differences in outdoor PM_2.5, receiving the energy package was associated with decreased winter exposures to PM_2.5 (-46%; 95% CI: -70, -2) and black carbon (-55%; -74, -25) and the summer increases were smaller (PM_2.5: 8%; -22, 51 and black carbon: 37%; -12, 113). However, PM_2.5 exposures remained 1.5-3 times higher than those of health-based international air pollution targets.

Impact of intervention of biomass cookstove technologies and kitchen characteristics on indoor air quality and human exposure in rural settings of India

This study investigates the impact of increased levels of indoor air pollution (IAP) caused due to biomass burning in the rural households of Northern India. A comparative assessment of the impact of traditional cookstoves (TCS) and improved cookstoves (ICS) coupled with the characteristics of kitchen was conducted to estimate the PM (PM₁₀, PM_2.5, PM₁), CO/CO₂ concentrations in the micro-environments of kitchen and living area of the households. The study incorporated both extensive and intensive real-time indoor air quality (IAQ) monitoring during the two cooking sessions of the day. The pollutant concentrations were reported in terms of 24-h as well as 8-h (cooking hours including morning and evening meal) averages. Influence of the three types of kitchen characteristics, i.e., enclosed, semi-enclosed and open was also comprehensively analyzed to measure its impact on the IAQ. In addition to this, the IAQ was further used to evaluate the particle size distribution (PSD), respiratory tract deposition and exposure index to assess its impact on health status of the exposed group including women involved in cooking practices. The results of the study highlighted that deployment of ICS would help in improving the IAQ of the kitchen area by resulting in reducing the concentrations of PM_10, PM_2.5, PM₁ and CO by 21-62%, 20-80%, 24-87% and 19-93%, respectively. It was also highlighted that the kitchen characteristics significantly influence the accumulation of air pollutants, demonstrated by the results that the IAQ being worst in the case of enclosed kitchen, resulted in the highest exposure index values. Multivariate regression models to predict PM₁ concentration were also developed for three kitchen categories for both TCS and ICS. Thus, the current study concludes that usage of ICS coupled with efficient designing of the kitchen can improve the overall IAQ of the household along with immense health benefits. Overall, the study emphasized the need of more comprehensive studies to fully assess the association of household air pollution (HAP) and health of individual in the rural settings by considering the toxicity of PM.

Emission of black carbon from rural households kitchens and assessment of lifetime excess cancer risk in villages of North India

The use of biomass solid fuels (BSFs) for cooking, contribute significantly to the household air pollution (HAP) in developing countries. Emissions resulting from a variety of BSFs (cow dung cakes, wood, and agriculture residues) contain a significant amount of air pollutants, which are now recognized for their role in climatic change and adverse human health impacts. In the current study, daily variations in black carbon (BC) or Short-Lived Climate Forcer concentrations were studied from rural household kitchens using portable aethalometer. The hourly average concentration of BC ranges from 5.4 μg·m^-3 to 34.9 μg·m^-3 for various types of household kitchens. The peak levels of BC were found to be significantly higher, when compared to World Health Organization PM_2.5 limits for ambient air and hence pose a threat to the health of the vulnerable population, i.e., women, children, older adults and those who have health problems. The study also highlights the variation of BC concentration in different kitchen type. The average BC concentration in indoor, outdoor and semi-open kitchen was observed to be 14.54, 14.28 and 24.69 μg·m^-3, respectively. The excess lifetime carcinogenic risk for cooking 4 h/day in these kitchens in the North Indian villages was estimated to be 1.25 × 10^-7, 1.22 × 10^-7, and 2.12 × 10^-7 respectively. Age-specific excess cancer deaths due to BC exposure were measured highest in children below four years of age in Chandigarh, India. Hence, there is a need to shift the BSF users to clean fuel alternatives to reduce the exposure to HAP. This can be achieved by generating local/regional evidences of BSFs associated health risks to support policy interventions. Further, more research is required to improve the air quality in indoor micro-environments and specifically in kitchens. NOVELTY: The first study reporting the near real-time measurements of BC from different types of rural households kitchens of north India. Diurnal pattern of BC concentration was also studied including the effect of chimney, ventilation and kitchen size on observed BC concentration. This study also estimates lifetime excess cancer risk due to BC exposure in rural households in India. The recent 'Global Burden of Disease' report identifies household air pollutants as a major cause of disease and disability in Asia. The study will help to plan suitable policies and intervention to reduce household air pollution in the region.

A Low-Cost Stove Use Monitor to Enable Conditional Cash Transfers

Conditional cash transfers (CCTs)-cash payments provided to households or specific household members who meet defined conditions or fulfill certain behaviors-have been extensively used in India to encourage antenatal care, institutional delivery, and vaccination. This paper describes the social design and technical development of a low-cost, meal-counting stove use monitor (the Pink Key) that enables a CCT based on liquefied petroleum gas (LPG) usage and presents pilot data from its testing and the initial deployment. The system consists of a sensing harness attached to a two-burner LPG stove and an easily removable datalogger. For each cooking event with LPG, households receive 2 rupees-less than the cost of fuel, but enough to partially defray LPG refill costs. The system could enable innovative "self-monitoring" at a large scale-participants initiate the CCT by bringing their Pink Key to antenatal clinic visits, where care providers download data and initiate payments, and participants return the sensor to their stove at home. The system aligns with existing Indian programs to improve health among poor, pregnant women, and contributes a new method to encourage the use of clean cooking technologies.

The impact of cookstove operation on PM2.5 and CO emissions: A comparison of laboratory and field measurements

Inefficient biomass combustion in traditional cookstoves generates high levels of household air pollution (HAP) that is associated with numerous adverse environmental and human health conditions. Many cookstoves have been evaluated using laboratory tests, but past studies revealed discrepancies between laboratory and field measurements. Fuel re-loading, a common operation in actual use but not required in the laboratory test, might be a contributing factor to this laboratory-field gap. In this study, we evaluated the pollutant emissions performance of a semi-gasifier cooking stove using both laboratory and field measurements. Emission factors and real-time properties of CO and PM_2.5 were separately measured during the following 4 phases of a typical cooking event: lighting, stable combustion, fuel re-loading and post fuel re-loading. We quantified the CO and PM_2.5 contributions to total cooking event emissions in each phase. We found over 70% lower PM_2.5 emissions and 60% lower CO emissions during 3 no re-loading laboratory tests compared with all 16 field tests. Lighting generated 83.8% ± 15.6% of the total PM_2.5 and 39.1% ± 7.8% of the total CO in laboratory tests without fuel re-loading, and 57.8% ± 33.5% and 37.9% ± 21.2% of the total PM_2.5 and CO in field tests, respectively. On average, fuel re-loading led to 29.1% ± 30.8% of PM_2.5 emissions and 24.9% ± 22.6% of CO emissions in 16 field tests, which also contributed to significant discrepancies between laboratory and field-based emissions. According to the ISO IWA tiered stove ratings for emissions, fuel re-loading led to at least one tier lower ranking in both laboratory and field cookstove tests. Fuel re-loading could be an important factor causing laboratory-field discrepancy of emissions, thus it could be considered in future cookstove selection and intervention projects.

Establishing a Demographic, Development and Environmental Geospatial Surveillance Platform in India: Planning and Implementation

BACKGROUND

Inadequate administrative health data, suboptimal public health infrastructure, rapid and unplanned urbanization, environmental degradation, and poor penetration of information technology make the tracking of health and well-being of populations and their social determinants in the developing countries challenging. Technology-integrated comprehensive surveillance platforms have the potential to overcome these gaps.

OBJECTIVE

This paper provides methodological insights into establishing a geographic information system (GIS)-integrated, comprehensive surveillance platform in rural North India, a resource-constrained setting.

METHODS

The International Clinical Epidemiology Network Trust International established a comprehensive SOMAARTH Demographic, Development, and Environmental Surveillance Site (DDESS) in rural Palwal, a district in Haryana, North India. The surveillance platform evolved by adopting four major steps: (1) site preparation, (2) data construction, (3) data quality assurance, and (4) data update and maintenance system. Arc GIS 10.3 and QGIS 2.14 software were employed for geospatial data construction. Surveillance data architecture was built upon the geospatial land parcel datasets. Dedicated software (SOMAARTH-1) was developed for handling high volume of longitudinal datasets. The built infrastructure data pertaining to land use, water bodies, roads, railways, community trails, landmarks, water, sanitation and food environment, weather and air quality, and demographic characteristics were constructed in a relational manner.

RESULTS

The comprehensive surveillance platform encompassed a population of 0.2 million individuals residing in 51 villages over a land mass of 251.7 sq km having 32,662 households and 19,260 nonresidential features (cattle shed, shops, health, education, banking, religious institutions, etc). All land parcels were assigned georeferenced location identification numbers to enable space and time monitoring. Subdivision of villages into sectors helped identify socially homogenous community clusters (418/676, 61.8%, sectors). Water and hygiene parameters of the whole area were mapped on the GIS platform and quantified. Risk of physical exposure to harmful environment (poor water and sanitation indicators) was significantly associated with the caste of individual household (P=.001), and the path was mediated through the socioeconomic status and density of waste spots (liquid and solid) of the sector in which these households were located. Ground-truthing for ascertaining the land parcel level accuracies, community involvement in mapping exercise, and identification of small habitations not recorded in the administrative data were key learnings.

CONCLUSIONS

The SOMAARTH DDESS experience allowed us to document and explore dynamic relationships, associations, and pathways across multiple levels of the system (ie, individual, household, neighborhood, and village) through a geospatial interface. This could be used for characterization and monitoring of a wide range of proximal and distal determinants of health.

Impact of cleaner fuel use and improved stoves on acute respiratory infections: evidence from India

Background

The use of cleaner fuel and improved stoves has been promoted as a means to lower harmful emissions from solid fuels. However, little is known about how exclusive use of cleaner fuels, mixed fuel use and improved stoves influences children's health.

Methods

We compared the impact of using liquefied petroleum gas (LPG) exclusively with mixed fuel use (LPG plus polluting fuels) and with exclusive use of polluting fuels on acute respiratory infections (ARI) among 16 157 children 0-4 years of age from households in the 2012 Indian Human Development Survey. Inverse probability weighting (IPW) procedures for multiple treatments were used for this evaluation.

Results

Children from households using LPG had a 5.0% lower probability of reporting ARI relative to exclusive users of polluting fuels, with larger effects (10.7%) in rural households. The probability of ARI in households using improved stoves and mixed fuel use was also lower in rural households, by 2.9% and 2.8%, respectively. The magnitude of effect varied across population subgroups, with the highest effects for children living in households living in kachha (low quality material) houses households identified as poor.

Conclusion

Use of LPG and improved stoves lowered the probability of ARI among children younger than 5 years.

Estimation of Short-term Mortality and Morbidity Attributed to Fine Particulate Matter in the Ambient Air of Eight Iranian Cities

Amongst the various pollutants in the air, particulate matters (PM) have significant adverse effects on human health. The current research is based on existing epidemiological literature for quantitative estimation of the current health impacts related to particulate matters in some selected principal Iranian megacities. In order to find the influence of air pollution on human health, we used the AirQ software tool presented by the World Health Organization (WHO) European Centre for Environment and Health (ECEH), Bilthoven Division. The adverse health outcomes used in the study consist of mortality (all causes excluding accidental causes), due to cardiovascular (CVD) and respiratory (RES) diseases, and morbidity (hospital admissions for CVD and RES causes). For this purpose, hourly PM₁₀ data were taken from the monitoring stations in eight study cities during 2011 and 2012. Results showed annual average concentrations of PM₁₀ and PM_2.5 in all megacities exceeded national and international air quality standards and even reached levels nearly ten times higher than WHO guidelines in some cities. Considering the short-term effects, PM_2.5 had the maximum effects on the health of the 19,048,000 residents of the eight Iranian cities, causing total mortality of 5,670 out of 87,907 during a one-year time-period. Hence, reducing concentrations and controlling air pollution, particularly the presence of particles, is urgent in these metropolises.

Maternal exposure to PM2.5 in south Texas, a pilot study

In this study, we characterized personal exposure to fine particulate matter (PM_2.5), black carbon (BC), and nicotine in pregnant women in Hidalgo County, where the hospitalization rates of childhood asthma are the highest in the state of Texas. The measurements were conducted over three non-consecutive sampling days for 17 participants in their third trimester. Measurements were partitioned into four microenvironments, i.e., Residential, Vehicular, Commercial, and Other, on the basis of GPS coordinates and temperature and humidity measurements. The daily average PM_2.5 mass concentration was 24.2 (standard deviation=22.0) μg/m³, with the highest daily mass concentration reaching 126.0μg/m³. The daily average BC concentration was 1.44 (SD=0.82) μg/m³, ranging from 0.5 to 5.4μg/m³. Hair nicotine concentrations were all near the detection level (i.e., 49.2pg/mg), indicating that the participants were not routinely exposed to tobacco smoke. The Residential microenvironment contributed dominantly to the mass concentration since the participants chiefly remained at home and cooking activities contributed significantly to the total PM_2.5. When compared to an ambient monitoring station, the person-specific PM_2.5 was frequently more than double the ambient measurement (10.4μg/m³ overall), revealing that even in regions where ambient concentrations are below national standards, individuals may be still be exposed to elevated PM_2.5 mass concentrations.

Impact of improved cookstoves on women's and child health in low and middle income countries: a systematic review and meta-analysis

OBJECTIVES

Improved biomass cookstoves may help reduce the substantial global burden of morbidity and mortality due to household air pollution (HAP) that disproportionately affects women and children in low and middle income countries (LMICs).

DESIGN

Systematic review and meta-analysis of (quasi-)experimental studies identified from 13 electronic databases (last update: 6 April 2018), reference and citation searches and via expert consultation.

SETTING

LMICs PARTICIPANTS: Women and children INTERVENTIONS: Improved biomass cookstoves MAIN OUTCOME MEASURES: Low birth weight (LBW), preterm birth, perinatal mortality, paediatric acute respiratory infections (ARIs) and COPD among women.

RESULTS

We identified 53 eligible studies, including 24 that met prespecified design criteria. Improved cookstoves had no demonstrable impact on paediatric lower ARIs (three studies; 11 560 children; incidence rate ratio (IRR)=1.02 (95% CI 0.84 to 1.24)), severe pneumonia (two studies; 11 061 children; IRR=0.88 (95% CI 0.39 to 2.01)), LBW (one study; 174 babies; OR=0.74 (95% CI 0.33 to 1.66)) or miscarriages, stillbirths and infant mortality (one study; 1176 babies; risk ratio (RR) change=15% (95% CI -13 to 43)). No (quasi-)experimental studies assessed preterm birth or COPD. In observational studies, improved cookstoves were associated with a significant reduction in COPD among women: two studies, 9757 participants; RR=0.74 (95% CI 0.61 to 0.90). Reductions in cough (four studies, 1779 participants; RR=0.72 (95% CI 0.60 to 0.87)), phlegm (four studies, 1779 participants; RR=0.65 (95% CI 0.52 to 0.80)), wheezing/breathing difficulty (four studies; 1779 participants; RR=0.41 (95% CI 0.29 to 0.59)) and conjunctivitis (three studies, 892 participants; RR=0.58 (95% CI 0.43 to 0.78)) were observed among women.

CONCLUSION

Improved cookstoves provide respiratory and ocular symptom reduction and may reduce COPD risk among women, but had no demonstrable child health impact.

REGISTRATION

PROSPERO: CRD42016033075.

Exposures to fine particulate matter (PM2.5) and birthweight in a rural-urban, mother-child cohort in Tamil Nadu, India

BACKGROUND

Exposure to PM_2.5 (fine particulate matter <less than 2.5µm in aerodynamic diameter) related to ambient and household air pollution has been associated with low birthweight. Few of these studies, however, have been conducted in high exposure settings that are commonly encountered in low and middle income countries (LMICs).

OBJECTIVES

We examined whether PM_2.5 exposures during pregnancy were associated with birthweight in an integrated rural-urban, mother-child cohort in the state of Tamil Nadu, India.

METHODS

We recruited 1285 pregnant women in the first trimester of pregnancy from primary health care centers and urban health posts and followed them until birth to collect antenatal care data and birthweight. We estimated pregnancy period PM _2.5 exposures through direct serial measurements of 24-h household PM_2.5 concentrations, performed across each trimester. Mothers also completed detailed questionnaires to provide data on covariates related to household, socio-economic, demographic and maternal health characteristics. The association between PM_2.5 exposures and birth weight was assessed using linear and logistic regression models that controlled for potential confounders.

RESULTS

A 10-μg/m³ increase in pregnancy period PM_2.5 exposures was associated with a 4g (95% CI: 1.08g, 6.76g) decrease in birthweight and 2% increase in prevalence of low birthweight [odds ratio(OR) = 1.02; 95%CI:1.005,1.041] after adjusting for gestational age, infant sex, maternal BMI, maternal age, history of a previous low birth weight child, birth order and season of conception.

CONCLUSIONS

The study provides some of the first quantitative effects estimates for linking rural-urban PM_2.5 exposures and birthweight in India, adding important evidence for this association from high exposure settings in LMICs, that also experience dual health burdens from ambient and household air pollution. Study results also point to the need for considering maternal PM_2.5 exposures alongside other risk factors for low birthweight in India.

Assessing Exposure to Household Air Pollution: A Systematic Review and Pooled Analysis of Carbon Monoxide as a Surrogate Measure of Particulate Matter

BACKGROUND

Household air pollution from solid fuel burning is a leading contributor to disease burden globally. Fine particulate matter (PM_2.5) is thought to be responsible for many of these health impacts. A co-pollutant, carbon monoxide (CO) has been widely used as a surrogate measure of PM_2.5 in studies of household air pollution.

OBJECTIVE

The goal was to evaluate the validity of exposure to CO as a surrogate of exposure to PM_2.5 in studies of household air pollution and the consistency of the PM_2.5-CO relationship across different study settings and conditions.

METHODS

We conducted a systematic review of studies with exposure and/or cooking area PM_2.5 and CO measurements and assembled 2,048 PM_2.5 and CO measurements from a subset of studies (18 cooking area studies and 9 personal exposure studies) retained in the systematic review. We conducted pooled multivariate analyses of PM_2.5-CO associations, evaluating fuels, urbanicity, season, study, and CO methods as covariates and effect modifiers.

RESULTS

We retained 61 of 70 studies for review, representing 27 countries. Reported PM_2.5-CO correlations (r) were lower for personal exposure (range: 0.22-0.97; median=0.57) than for cooking areas (range: 0.10-0.96; median=0.71). In the pooled analyses of personal exposure and cooking area concentrations, the variation in ln(CO) explained 13% and 48% of the variation in ln(PM_2.5), respectively.

CONCLUSIONS

Our results suggest that exposure to CO is not a consistently valid surrogate measure of exposure to PM_2.5. Studies measuring CO exposure as a surrogate measure of PM exposure should conduct local validation studies for different stove/fuel types and seasons. https://doi.org/10.1289/EHP767.

Sri Lanka Pilot Study to Examine Respiratory Health Effects and Personal PM2.5 Exposures from Cooking Indoors

A pilot study of indoor air pollution produced by biomass cookstoves was conducted in 53 homes in Sri Lanka to assess respiratory conditions associated with stove type ("Anagi" or "Traditional"), kitchen characteristics (e.g., presence of a chimney in the home, indoor cooking area), and concentrations of personal and indoor particulate matter less than 2.5 micrometers in diameter (PM2.5). Each primary cook reported respiratory conditions for herself (cough, phlegm, wheeze, or asthma) and for children (wheeze or asthma) living in her household. For cooks, the presence of at least one respiratory condition was significantly associated with 48-h log-transformed mean personal PM2.5 concentration (PR = 1.35; p < 0.001). The prevalence ratio (PR) was significantly elevated for cooks with one or more respiratory conditions if they cooked without a chimney (PR = 1.51, p = 0.025) and non-significantly elevated if they cooked in a separate but poorly ventilated building (PR = 1.51, p = 0.093). The PRs were significantly elevated for children with wheeze or asthma if a traditional stove was used (PR = 2.08, p = 0.014) or if the cooking area was not partitioned from the rest of the home (PR = 2.46, p = 0.012). For the 13 children for whom the cooking area was not partitioned from the rest of the home, having a respiratory condition was significantly associated with log-transformed indoor PM2.5 concentration (PR = 1.51; p = 0.014).