Effect estimates (95% confidence intervals) and variance components from linear mixed effects models to predict natural log personal PM_2.5 (216 24-hour exposure measures among 116 subjects).

*<p>Stove by CO interaction effect = −0.00 (−0.22, 0.22).</p

Scatter plot of simultaneous 24-hour personal fine particles (PM_2.5) and personal carbon monoxide (CO).

<p>Lines for each stove type (red for open fire, blue for chimney stove) using equation PM_2.5 = e^{(<b>−2.13+0.61*ln(CO) − 0.36*chimney</b>)} estimated from linear mixed effects regression model with natural log-transformed exposures (216 measurements among 116 women).</p

Pollutant Emissions and Energy Efficiency under Controlled Conditions for Household Biomass Cookstoves and Implications for Metrics Useful in Setting International Test Standards

Realistic metrics and methods for testing household biomass cookstoves are required to develop standards needed by international policy makers, donors, and investors. Application of consistent test practices allows emissions and energy efficiency performance to be benchmarked and enables meaningful comparisons among traditional and advanced stove types. In this study, 22 cookstoves burning six fuel types (wood, charcoal, pellets, corn cobs, rice hulls, and plant oil) at two fuel moisture levels were examined under laboratory-controlled operating conditions as outlined in the Water Boiling Test (WBT) protocol, Version 4. Pollutant emissions (carbon dioxide, carbon monoxide, methane, total hydrocarbons, and ultrafine particles) were continuously monitored. Fine particle mass was measured gravimetrically for each WBT phase. Additional measurements included cookstove power, energy efficiency, and fuel use. Emission factors are given on the basis of fuel energy, cooking energy, fuel mass, time, and cooking task or activity. The lowest PM_2.5 emissions were 74 mg MJ_delivered^–1 from a technologically advanced cookstove compared with 700–1400 mg MJ_delivered^–1 from the base-case open 3-stone cookfire. The highest thermal efficiency was 53% compared with 14–15% for the 3-stone cookfire. Based on these laboratory-controlled test results and observations, recommendations for developing potentially useful metrics for setting international standards are suggested

Evaluating the Performance of Household Liquefied Petroleum Gas Cookstoves

Liquefied petroleum gas (LPG) cookstoves are considered to be an important solution for mitigating household air pollution; however, their performance has rarely been evaluated. To fill the data and knowledge gaps in this important area, 89 laboratory tests were conducted to quantify efficiencies and pollutant emissions from five commercially available household LPG stoves under different burning conditions. The mean thermal efficiency (±standard deviation) for the tested LPG cookstoves was 51 ± 6%, meeting guidelines for the highest tier level (Tier 4) under the International Organization for Standardization, International Workshop Agreement 11. Emission factors of CO₂, CO, THC, CH₄, and NO_<i>x</i> on the basis of useful energy delivered (MJ_d) were 142 ± 17, 0.77 ± 0.55, 130 ± 196, 5.6 ± 8.2, and 46 ± 9 mg/MJ_d, respectively. Approximately 90% of the PM_2.5 data were below the detection limit, corresponding to an emission rate below 0.11 mg/min. For those data above the detection limit, the average emission factor was 2.4 ± 1.6 mg/MJ_d, with a mean emission rate of 0.20 ± 0.16 mg/min. Under the specified gas pressure (2.8 kPa), but with the burner control set to minimum air flow rate, less complete combustion resulted in a visually yellow flame, and CO, PM_2.5, EC, and BC emissions all increased. LPG cookstoves met guidelines for Tier 4 for both CO and PM_2.5 emissions and mostly met the World Health Organization Emission Rate Targets set to protect human health

Patterns of Stove Usage after Introduction of an Advanced Cookstove: The Long-Term Application of Household Sensors

Household air pollution generated from solid fuel use for cooking is one of the leading risk factors for ill-health globally. Deployment of advanced cookstoves to reduce emissions has been a major focus of intervention efforts. However, household usage of these stoves and resulting changes in usage of traditional polluting stoves is not well characterized. In Palwal District, Haryana, India, we carried out an intervention utilizing the Philips HD4012 fan-assisted stove, one of the cleanest biomass stoves available. We placed small, unobtrusive data-logging iButton thermometers on both the traditional and Philips stoves to collect continuous data on use patterns in 200 homes over 60 weeks. Intervention stove usage declined steadily over time and stabilized after approximately 200 days; use of the traditional stove remained relatively constant. We additionally evaluated how well short-duration usage measures predicted long-term use. Measuring usage over time of both traditional and intervention stoves provides better understanding of cooking behaviors and can lead to more precise quantification of potential exposure reductions and consequent health benefits attributable to interventions

Left, a traditional ger dwelling. right, houses typical of the peri-urban regions of UB.

<p>(Credit: L. Drew Hill).</p

Estimates of age-specific city-wide population and household number by home type, and estimated household size.

<p>Estimates of age-specific city-wide population and household number by home type, and estimated household size.</p

Population weighted wintertime outdoor PM_2.5 concentrations.

<p>Whiskers represent 10^th and 90^th percentile concentrations.</p

Summary of the assumptions made for emissions sources, by category ¹.

<p>Summary of the assumptions made for emissions sources, by category <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0186834#t001fn001" target="_blank">¹</a>.</p

Estimated burden averted from BAU by measures taken in Pathways 1 and 2 (2014–2024).

<p>Pathway 2 would save more lives than Pathway 1 by more than a factor of 2. Lower and upper bounds on total values are shown as whiskers. Note the greater importance of child ALRI in averted DALYs as compared to averted deaths.</p