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Biomass combustion for cooking and heating releases particulate matter (PM 2.5 ) that contributes to household air pollution. Fuel and stove types affect the chemical composition of household PM, as does infiltration of outdoor PM. Characterization of these impacts can inform future exposure assessments and epidemiologic studies, but is currently limited. In this study, we measured chemical components of PM 2.5 (water-soluble organic matter [WSOM], ions, black carbon, elements, organic tracers) in rural Chinese households using traditional biomass stoves, semi-gasifier stoves with pelletized biomass, and/or non-biomass stoves. We distinguished households using one stove type (traditional, semi-gasifier, or LPG/electric) from those using multiple stoves/fuels. WSOM concentrations were higher in households using only semi-gasifier or traditional stoves (31%-33%) than in those with exclusive LPG/electric stove (13%) or mixed stove use (12%-22%). Inorganic ions comprised 14% of PM in exclusive LPG/electric households, compared to 1%-5% of PM in households using biomass. Total PAH content was much higher in households that used traditional stoves (0.8-2.8 mg/g PM) compared to those that did not (0.1-0.3 mg/g PM). Source apportionment revealed that biomass burning comprised 27%-84% of PM 2.5 in households using biomass. In all samples, identified outdoor sources (vehicles, dust, coal combustion, secondary aerosol) contributed 10%-20% of household PM 2.5 ., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Telomere shortening is associated with early mortality and chronic disease. Recent studies indicate that environmental exposures, including urban and traffic-related air pollution, may shorten telomeres. Associations between exposure to household air pollution from solid fuel stoves and telomere length have not been evaluated., Methods: Among 137 rural Chinese women using biomass stoves ([Formula: see text] of age), we measured 48-h personal exposures to fine particulate matter [PM [Formula: see text] in aerodynamic diameter ([Formula: see text])] and black carbon and collected oral DNA on up to three occasions over a period of 2.5 y. Relative telomere length (RTL) was quantified using a modified real-time polymerase chain reaction protocol. Mixed effects regression models were used to investigate the exposure–response associations between household air pollution and RTL, adjusting for key sociodemographic, behavioral, and environmental covariates., Results: Women's daily exposures to air pollution ranged from [Formula: see text] for [Formula: see text] ([Formula: see text]) and [Formula: see text] for black carbon ([Formula: see text]). Natural cubic spline models indicated a mostly linear association between increased exposure to air pollution and shorter RTL, except at very high concentrations where there were few observations. We thus modeled the linear associations with all observations, excluding the highest 3% and 5% of exposures. In covariate-adjusted models, an interquartile range (IQR) increase in exposure to black carbon ([Formula: see text]) was associated with shorter RTL [all observations: [Formula: see text] (95% CI: [Formula: see text], [Formula: see text]); excluding highest 5% exposures: [Formula: see text] (95% CI: [Formula: see text], [Formula: see text])]. Further adjustment for outdoor temperature brought the estimates closer to zero [all observations: [Formula: see text] (95% CI: [Formula: see text], 0.06); excluding highest 5% exposures: [Formula: see text] (95% CI: [Formula: see text], [Formula: see text])]. Models with [Formula: see text] as the exposure metric followed a similar pattern., Conclusion: Telomere shortening, which is a biomarker of biological aging and chronic disease, may be associated with exposure to air pollution in settings where household biomass stoves are commonly used. https://doi.org/10.1289/EHP4041.

Fine particulate matter (PM 2.5 ) has health effects that may depend on its sources and chemical composition. Few studies have quantified the composition of personal and area PM 2.5 in rural settings over the same time period. Yet, this information would shed important light on the sources influencing personal PM 2.5 exposures. This study investigated the sources and chemical composition of 40 personal exposure, 40 household, and 36 ambient PM 2.5 samples collected in the non-heating and heating seasons in rural southwestern China. Chemical analysis included black carbon (BC), water-soluble components (ions, organic carbon), elements, and organic tracers. Source apportionment was conducted using organic tracer concentrations in a Chemical Mass Balance model. Biomass burning was the largest identified PM 2.5 source contributor to household (average, SD: 48 ± 11%) and exposures (31 ± 6%) in both seasons, and ambient PM 2.5 in winter (20 ± 4%). Food cooking also contributed to household and personal PM, reaching approximately half of the biomass contributions. Secondary inorganic aerosol was the major identified source in summertime ambient PM 2.5 (32 ± 14%), but was present in all samples (summer: 10 ± 3% [household], 13 ± 6% [exposures]; winter: 18 ± 2% [ambient], 7 ± 2% [household], 8 ± 2% [exposures]). Dust concentrations and fractional contribution to total PM 2.5 were higher in summer exposure samples (7 ± 4%) than in ambient or household samples (6 ± 1% and 2 ± 1%, respectively). Indoor sources comprised up to one-fifth of ambient PM 2.5 , and outdoor sources (vehicles, secondary aerosols) contributed up to 15% of household PM 2.5 . While household sources were the main contributors to PM 2.5 exposures in terms of mass, inorganic components of personal exposures differed from household samples. Based on these findings, health-focused initiatives to reduce harmful PM 2.5 exposures may consider a coordinated approach to address both indoor and outdoor PM 2.5 source contributors., (Copyright © 2018. Published by Elsevier B.V.)

Background: Air pollution from cooking with solid fuels is a potentially modifiable risk factor for increased blood pressure and may lead to eye irritation., Objectives: To evaluate whether a climate motivated cookstove intervention reduced blood pressure and eye irritation symptoms in Indian women., Methods: Households using traditional stoves were randomized to receive a rocket stove or continue using traditional stoves. Systolic (SBP) and diastolic blood pressure (DBP), and self-reported eye symptoms were measured twice, pre-intervention and at least 124 days post-intervention in women > 25 years old in control (N = 111) and intervention (N = 111) groups in rural Karnataka, India. Daily (24-h) fine particle (PM 2.5 ) mass and absorbance (Abs) were measured in cooking areas at each visit. Mixed-effect models were used to estimate before-and-after differences in SBP, DBP and eye symptoms., Results: We observed a lower SBP (-2.0 (-4.5, 0.5) mmHg) and DBP (-1.1 (-2.9, 0.6) mmHg) among exclusive users of intervention stove, although confidence intervals included zero. Stacking or mixed use of intervention and traditional stoves contributed to a small increase in SBP 2.6 (-0.4, 5.7) mmHg) and DBP (1.2 (-0.9, 3.3) mmHg). Exclusive and mixed stove users experienced higher post-intervention reductions, on average, in self-reported eye irritation symptoms for burning sensation in eyes, and eyes look red often compared to control. Median air pollutant concentrations increased post-intervention in all stove groups, with the lowest median PM 2.5 increase in the exclusive intervention stove group., Conclusions: Health benefits were limited due to stacking and lower-than-predicted efficiency of the intervention stove in the field. Stove adoption and use behavior, in addition to stove technology, affects achievement of health co-benefits. Carbon-financing schemes need to align with international guidelines that have been set based on health outcomes to maximize health co-benefits from cookstove interventions., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Decades of intervention programs that replaced traditional biomass stoves with cleaner-burning technologies have failed to meet the World Health Organization (WHO) interim indoor air quality target of 35-μg m -3 for PM 2.5 . Many attribute these results to continued use of biomass stoves and poor outdoor air quality, though the relative impacts of these factors have not been empirically quantified., Methods: We measured 496 days of real-time stove use concurrently with outdoor and indoor air pollution (PM 2.5 ) in 150 rural households in Sichuan, China. The impacts of stove use patterns and outdoor air quality on indoor PM 2.5 were quantified. We also estimated the potential avoided cardiovascular mortality in southwestern China associated with transition from traditional to clean fuel stoves using established exposure-response relationships., Results: Mean daily indoor PM 2.5 was highest in homes using both wood and clean fuel stoves (122 μg m -3 ), followed by exclusive use of wood stoves (106 μg m -3 ) and clean fuel stoves (semi-gasifiers: 65 μg m -3 ; gas or electric: 55 μg m -3 ). Wood stoves emitted proportionally higher indoor PM 2.5 during ignition, and longer stove use was not associated with higher indoor PM 2.5 . Only 24% of days with exclusive use of clean fuel stoves met the WHO indoor air quality target, though this fraction rose to 73% after subtracting the outdoor PM 2.5 contribution. Reduced PM 2.5 exposure through exclusive use of gas or electric stoves was estimated to prevent 48,000 yearly premature deaths in southwestern China, with greater reductions if local outdoor PM 2.5 is also reduced., Conclusions: Clean stove and fuel interventions are not likely to reduce indoor PM 2.5 to the WHO target unless their use is exclusive and outdoor air pollution is sufficiently low, but may still offer some cardiovascular benefits., (Copyright © 2018. Published by Elsevier Ltd.)

Background: Approximately three billion people are exposed to household air pollution (HAP) from solid fuel cookstoves. Studies from single settings have linked HAP with elevated blood pressure (BP), but no evidence exists from multi-country analyses., Objectives: Using nationally representative and internationally comparable data, we examined the association between solid fuel use and BP in 77,605 largely premenopausal women (aged 15-49) from ten resource-poor countries., Methods: We obtained data on systolic and diastolic BP, self-reported primary cooking fuel, health and socio-demographic characteristics from 12 Demographic and Health Surveys conducted in Albania, Armenia, Azerbaijan, Bangladesh, Benin, Ghana, Kyrgyzstan, Lesotho, Namibia, and Peru. We estimated associations between history of fuel use [solid fuel (coal or biomass) versus clean fuel (electricity or gas)] with systolic and diastolic BP and hypertension using a meta-analytical approach., Results: Overall, the country-level mean systolic and diastolic BP were 117 (range: 111-127) and 74 (71-83) mmHg, respectively. The country-level mean age of the women was 30.8 years (range: 28.4-32.9). The prevalence of solid fuel use was 46.0% (range: 4.1-95.8). In adjusted, pooled analyses, primary use of solid fuel was associated with 0.58mmHg higher systolic BP (95% CI: 0.23, 0.93) as compared to primary use of clean fuel. The pooled estimates for diastolic BP and pulse pressure were also positive, but the confidence intervals contained zero. The pooled odds of hypertension was [OR = 1.07 (95% CI: 0.99, 1.16)], an effect that was driven by rural participants for whom solid fuel use was associated with a 16% greater odds of hypertension [OR = 1.16 (95% CI: 1.01, 1.35)]., Conclusions: Cooking with solid fuels was associated with small increases in BP and odds of hypertension. Use of cleaner fuels like gas or electricity may reduce cardiovascular risk in developing countries, particularly among rural residents., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Cooking and heating with coal and biomass is the main source of household air pollution in China and a leading contributor to disease burden. As part of a baseline assessment for a household energy intervention program, we enrolled 205 adult women cooking with biomass fuels in Sichuan, China and measured their 48-h personal exposure to fine particulate matter (PM2.5) and carbon monoxide (CO) in winter and summer. We also measured the indoor 48-h PM2.5 concentrations in their homes and conducted outdoor PM2.5 measurements during 101 (74) days in summer (winter). Indoor concentrations of CO and nitrogen oxides (NO, NO2) were measured over 48-h in a subset of ~80 homes. Women's geometric mean 48-h exposure to PM2.5 was 80μg/m(3) (95% CI: 74, 87) in summer and twice as high in winter (169μg/m(3) (95% CI: 150, 190), with similar seasonal trends for indoor PM2.5 concentrations (winter: 252μg/m(3); 95% CI: 215, 295; summer: 101μg/m(3); 95% CI: 91, 112). We found a moderately strong relationship between indoor PM2.5 and CO (r=0.60, 95% CI: 0.46, 0.72), and a weak correlation between personal PM2.5 and CO (r=0.41, 95% CI: -0.02, 0.71). NO2/NO ratios were higher in summer (range: 0.01 to 0.68) than in winter (range: 0 to 0.11), suggesting outdoor formation of NO2 via reaction of NO with ozone is a more important source of NO2 than biomass combustion indoors. The predictors of women's personal exposure to PM2.5 differed by season. In winter, our results show that primary heating with a low-polluting fuel (i.e., electric stove or wood-charcoal) and more frequent kitchen ventilation could reduce personal PM2.5 exposures. In summer, primary use of a gaseous fuel or electricity for cooking and reducing exposure to outdoor PM2.5 would likely have the greatest impacts on personal PM2.5 exposure., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Efforts to introduce more efficient stoves increasingly leverage carbon-finance to scale up dissemination of interventions. We conducted a randomized intervention study to evaluate a Clean Development Mechanism approved stove replacement impact on fuelwood usage, and climate and health-relevant air pollutants. We randomly assigned 187 households to either receive the intervention or to continue using traditional stoves. Measurements of fine particulate matter (PM2.5) and absorbance were conducted in cooking areas, village center and at upwind background site. There were minor and overlapping seasonal differences (post- minus preintervention change) between control and intervention groups for median (95% CI) fuel use (-0.60 (-1.02, -0.22) vs -0.52 (-1.07, 0.00) kg day(-1)), and 24 h absorbance (35 (18, 60) vs 36 (22, 50) × 10(-6) m(-1)); for 24 h PM2.5, there was a higher (139 (61,229) vs 73(-6, 156) μg m(-3))) increase in control compared to intervention homes between the two seasons. Forty percent of the intervention homes continued using traditional stoves. For intervention homes, absorbance-to-mass ratios suggest a higher proportion of black carbon in PM2.5 emitted from intervention compared with traditional stoves. Absent of field-based evaluation, stove interventions may be pursued that fail to realize expected carbon reductions or anticipated health and climate cobenefits.

Background: Kerosene is a widely used cooking and lighting fuel in developing countries. The potential respiratory health effects of cooking with kerosene relative to cooking with cleaner fuels such as liquefied petroleum gas (LPG) have not been well characterised., Methods: We sampled 600 households from six urban neighbourhoods in Bangalore, India. Each household's primary cook, usually the woman of the house, was interviewed to collect information on current domestic fuel use and whether there was any presence of respiratory symptoms or illness in her or in the children in the household. Our analysis was limited to 547 adult females (ages 18-85) and 845 children (ages 0-17) in households exclusively cooking with either kerosene or LPG. We investigated the associations between kerosene use and the likelihood of having respiratory symptoms or illness using multivariate logistic regression models., Results: Among adult women, cooking with kerosene was associated with cough (OR=1.88; 95% CI 1.19 to 2.99), bronchitis (OR=1.54; 95% CI 1.00 to 2.37), phlegm (OR=1.51; 95% CI 0.98 to 2.33) and chest illness (OR=1.61; 95% CI 1.02 to 2.53), relative to cooking with LPG in the multivariate models. Among children, living in a household cooking with kerosene was associated with bronchitis (OR=1.91; 95% CI 1.17 to 3.13), phlegm (OR=2.020; 95% CI 1.29 to 3.74) and chest illness (OR=1.70; 95% CI 0.99 to 2.90) after adjusting for other covariates. We also found associations between kerosene use and wheezing, difficulty breathing and asthma in adults and cough and wheezing in children, though these associations were not statistically significant., Conclusions: Women and children in households cooking with kerosene were more likely to have respiratory symptoms and illnesses compared with those in households cooking with LPG. Transitioning from kerosene to LPG for cooking may improve respiratory health among adult women and children in this population., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Air pollution in China and other parts of Asia poses large health risks and is an important contributor to global climate change. Almost half of Chinese homes use biomass and coal fuels for cooking and heating. China's economic growth and infrastructure development has led to increased emissions from coal-fired power plants and an expanding fleet of motor vehicles. Black carbon (BC) from incomplete biomass and fossil fuel combustion is the most strongly light-absorbing component of particulate matter (PM) air pollution and the second most important climate-forcing human emission. PM composition and sources may also be related to its human health impact. We enrolled 280 women living in a rural area of northwestern Yunnan where biomass fuels are commonly used. We measured their blood pressure, distance from major traffic routes, and daily exposure to BC (pyrolytic biomass combustion), water-soluble organic aerosol (organic aerosol from biomass combustion), and, in a subset, hopane markers (motor vehicle emissions) in winter and summer. BC had the strongest association with systolic blood pressure (SBP) (4.3 mmHg; P < 0.001), followed by PM mass and water-soluble organic mass. The effect of BC on SBP was almost three times greater in women living near the highway [6.2 mmHg; 95% confidence interval (CI), 3.6 to 8.9 vs. 2.6 mmHg; 95% CI, 0.1 to 5.2]. Our findings suggest that BC from combustion emissions is more strongly associated with blood pressure than PM mass, and that BC's health effects may be larger among women living near a highway and with greater exposure to motor vehicle emissions.

Household air pollution from solid fuel combustion is the leading environmental health risk factor globally. In China, almost half of all homes use solid fuel to meet their household energy demands. Gasifier cookstoves offer a potentially affordable, efficient, and low-polluting alternative to current solid fuel combustion technology, but pollutant emissions and energy efficiency performance of this class of stoves are poorly characterized. In this study, four Chinese gasifier cookstoves were evaluated for their pollutant emissions and efficiency using the internationally recognized water boiling test (WBT), version 4.1.2. WBT performance indicators included PM2.5, CO, and CO2 emissions and overall thermal efficiency. Laboratory investigation also included evaluation of pollutant emissions (PM2.5 and CO) under stove operating conditions designed to simulate common Chinese cooking practices. High power average overall thermal efficiencies ranged from 22 to 33%. High power average PM2.5 emissions ranged from 120 to 430 mg/MJ of useful energy, and CO emissions ranged from 1 to 30 g/MJ of useful energy. Compared with several widely disseminated "improved" cookstoves selected from the literature, on average, the four Chinese gasifier cookstoves had lower PM2.5 emissions and higher CO emissions. The recent International Organization for Standardization (ISO) International Workshop Agreement on tiered cookstove ranking was developed to help classify stove performance and identify the best-performing stoves. The results from this study highlight potential ways to further improve this approach. Medium power stove operation emitted nearly twice as much PM2.5 as was emitted during high power stove operation, and the lighting phase of a cooking event contributed 45% and 34% of total PM2.5 emissions (combined lighting and cooking). Future approaches to laboratory-based testing of advanced cookstoves could improve to include greater differentiation between different modes of stove operation, beyond those evaluated with the WBT.

BACKGROUND: Telomere shortening is associated with early mortality and chronic disease. Recent studies indicate that environmental exposures, including urban and traffic-related air pollution, may shorten telomeres. Associations between exposure to household air pollution from solid fuel stoves and telomere length have not been evaluated. METHODS: Among 137 rural Chinese women using biomass stoves (mean=55 y of age), we measured 48-h personal exposures to fine particulate matter [PM ≤ 2:5 lm in aerodynamic diameter (PM2:5)] and black carbon and collected oral DNA on up to three occasions over a period of 2.5 y. Relative telomere length (RTL) was quantified using a modified real-time polymerase chain reaction protocol. Mixed effects regression models were used to investigate the exposure-response associations between household air pollution and RTL, adjusting for key sociodemographic, behavioral, and environmental covariates. RESULTS: Women's daily exposures to air pollution ranged from 13-1,136 lg=m3 for PM2:5 (mean=154) and 0:1-34 lg=m3 for black carbon (mean=3:6). Natural cubic spline models indicated a mostly linear association between increased exposure to air pollution and shorter RTL, except at very high concentrations where there were few observations. We thus modeled the linear associations with all observations, excluding the highest 3% and 5% of exposures. In covariate-adjusted models, an interquartile range (IQR) increase in exposure to black carbon (3:1 lg=m3) was associated with shorter RTL [all observations: −0:27 (95% CI: −0:48, −0:06); excluding highest 5% exposures: −1:10 (95% CI: −1:63, −0:57)]. Further adjustment for outdoor temperature brought the estimates closer to zero [all observations: −0:15 (95% CI: −0:36, 0.06); excluding highest 5% exposures: −0:68 (95% CI: −1:26, −0:10)]. Models with PM2:5 as the exposure metric followed a similar pattern. CONCLUSION: Telomere shortening, which is a biomarker of biological aging and chronic disease, may be associated with exposure to air pollution in settings where household biomass stoves are commonly used. [ABSTRACT FROM AUTHOR]

Objective: We evaluated the exposure-response associations between personal exposure to air pollution from biomass stoves and multiple vascular and haemodynamic parameters in rural Chinese women.Methods: We analysed the baseline information from a longitudinal study in southwestern China. Women's brachial and central blood pressure and pulse pressure, carotid-femoral pulse wave velocity and augmentation index, and their 48-hour personal exposures to fine particulate matter (PM2.5) and black carbon were measured in summer and winter. We evaluated the associations between exposure to air pollution and haemodynamic parameters using mixed-effects regression models adjusted for known cardiovascular risk factors.Results: Women's (n=205, ages 27-86 years) exposures to PM2.5 and black carbon ranged from 14 µg/m3 to 1405 µg/m3 and 0.1-121.8 µg/m3, respectively. Among women aged ≥50 years, increased PM2.5 exposure was associated with higher systolic (brachial: 3.5 mm Hg (P=0.05); central: 4.4 mm Hg (P=0.005)) and diastolic blood pressure (central: 1.3 mm Hg (P=0.10)), higher pulse pressure (peripheral: 2.5 mm Hg (P=0.05); central: 2.9 mm Hg (P=0.008)) and lower peripheral-central pulse pressure amplification (-0.007 (P=0.04)). Among younger women, the associations were inconsistent in the direction of effect and not statistically significant. Increased PM2.5 exposure was associated with no difference in pulse wave velocity and modestly higher augmentation index though the CI included zero (1.1%; 95% CI -0.2% to 2.4%). Similar associations were found for black carbon exposure.Conclusions: Exposure to household air pollution was associated with higher blood pressure and central haemodynamics in older Chinese women, with no associations observed with pulse wave velocity. [ABSTRACT FROM AUTHOR]

Exposure to air pollution is a major risk factor globally and particularly in Asia. A large portion of air pollutants result from residential combustion of solid biomass and coal fuel for cooking and heating. This study presents a regional modeling sensitivity analysis to estimate the impact of residential emissions from cooking and heating activities on the burden of disease at a provincial level in China. Model surface PM2.5 fields are shown to compare well when evaluated against surface air quality measurements. Scenarios run without residential sector and residential heating emissions are used in conjunction with the Global Burden of Disease 2013 framework to calculate the proportion of deaths and disability adjusted life years attributable to PM2.5 exposure from residential emissions. Overall, we estimate that 341 000 (306 000-370 000; 95% confidence interval) premature deaths in China are attributable to residential combustion emissions, approximately a third of the deaths attributable to all ambient PM2.5 pollution, with 159 000 (142 000-172 000) and 182 000 (163 000-197 000) premature deaths from heating and cooking emissions, respectively. Our findings emphasize the need to mitigate emissions from both residential heating and cooking sources to reduce the health impacts of ambient air pollution in China. [ABSTRACT FROM AUTHOR]