Lung Function in Rural Guatemalan Women Before and After a Chimney Stove Intervention to Reduce Woodsmoke Exposure:Results From RESPIRE and CRECER. Chest, June 2015.
Authors: Michael Guarnieri; Esperanza Diaz; Daniel Pope; Ellen Eisen; Jennifer Mann; Kirk R. Smith; Tone Smith-Sivertsen; Nigel Bruce; John Balmes
Background: Chronic Obstructive Pulmonary Disease (COPD) is the third most frequent cause of death globally with much of this burden attributable to household biomass smoke exposure in developing countries. As biomass smoke exposure is also associated with cardiovascular disease, lower respiratory infection, lung cancer, and cataracts, it presents an important target for public health intervention.
Methods: Lung function in Guatemalan women exposed to woodsmoke from open fires was measured throughout the RESPIRE stove intervention trial, and continued during the CRECER cohort study. In RESPIRE, early stove households received a chimney woodstove at the beginning of the 18-month trial while delayed stove households received a stove at trial completion. Personal exposure to woodsmoke was assessed with exhaled breath carbon monoxide and personal CO tubes. Change in lung function between intervention groups and as a function of woodsmoke exposure was assessed using random effects models.
Results: Of 306 women participating in both studies, acceptable spirometry was collected in 129 early stove and 136 delayed stove households (n=265), with 5.6 years mean follow-up. Despite reduced woodsmoke exposures in early stove households, there were no significant differences in any of the measured spirometric variables during the study period; FEV1, FVC, FEV1/FVC ratio, and annual change, after adjustment for confounding.
Conclusion: In these young Guatemalan women, there was no association between lung function and early randomization to a chimney stove or personal woodsmoke exposure. Future stove intervention trials should incorporate cleaner stoves, longer follow-up, or potentially susceptible groups to identify meaningful differences in lung function.
Biogas: Clean Energy Access with Low-Cost Mitigation of Climate Change, 2015. World Bank.
Authors: E. Somanathan, Randall Bluffstone
This paper finds that the mean reduction in household firewood collection associated with use of a biogas plant for cooking is about 1,100 kilograms per year from a mean of about 2,400 kilograms per year. This estimate is derived by comparing only households with and without biogas in the same village, thus effectively removing the influence of many potential confounders. Further controls for important determinants of firewood collection, such as household size, per capita consumption expenditure, cattle ownership, and unemployment are used to identify the effect of biogas adoption on firewood collection.
Bounds on omitted variable bias are derived with the proportional selection assumption. The central estimate is much smaller than those in the previous literature, but is still large enough for the cost of adopting biogas to be significantly reduced via carbon offsets at a modest carbon price of $10 per ton of CO2e when using central estimates of emission factors and global warming potentials of pollutants taken from the scientific literature.
Use of Systematic Review and Meta-Analysis in Environmental Health Epidemiology: a Systematic Review and Comparison with Guidelines. Current Environmental Health Reports, 2015 :62 DOI: 10.1007/s40572-015-0062-z
Authors: Mary C. Sheehan and Juleen Lam. Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA , Mary C. Sheehan Email: msheeh10@jhu.edu
Systematic review (SR) and meta-analysis (MA) have potential to contribute substantially to environmental health (EH) risk assessment and policy-making, provided study questions are clear and methods sound. We undertook a systematic review of the published epidemiological literature for studies using both SR and MA examining associations between chronic low-dose chemical exposures and adverse health outcomes in general populations and compared actual methods and reporting with a checklist based on available published guidelines.
We identified 48 EH SRMAs meeting these criteria. Associations were mainly positive and statistically significant, often involving large populations. A majority of studies followed most general SRMA guidance, although we identified weaknesses in problem formulation, study search, selection and data extraction, and integrating policy implications. Fewer studies followed EH-specific SRMA recommendations, particularly regarding exposure heterogeneity and other risks of bias. Development and adoption of EH-specific SRMA guidelines would contribute to strengthening these tools for public health decision-making.
Children’s personal exposure to air pollution in rural villages in Bhutan. Environmental Research, July 2015.
Authors: Tenzin Wangchuka, Mandana Mazaheri, et al.
This study quantified school children’s daily personal exposure to ultrafine particles (UFP) using real-time monitoring, as well as volatile organic compounds (VOCs) and NO2 using passive sampling in rural Bhutan in order to determine the factors driving the exposures. An activity diary was used to track children’s time activity patterns, and difference in mean exposure levels across sex and indoor/outdoor were investigated with ANOVA. 82 children, attending three primary schools participated in this study; S1 and S2 during the wet season and S3 during the dry season.
Mean daily UFP exposure (cm–3) was 1.08×104 for children attending S1, 9.81×103 for S2, and 4.19×104 for S3. The mean daily NO2 exposure (µg m−3) was 4.27 for S1, 3.33 for S2 and 5.38 for S3 children. Likewise, children attending S3 also experienced higher daily exposure to a majority of the VOCs than those attending S1 and S2. Time-series of UFP personal exposures provided detailed information on identifying sources of these particles and quantifying their contributions to the total daily exposures for each microenvironment.
The highest UFP exposure resulted from cooking/eating, contributing to 64% of the daily exposure, due to firewood combustion in houses using traditional mud cookstoves. The lowest UFP exposures were during the hours that children spent outdoors at school. The outcomes of this study highlight the significant contributions of lifestyle and socio-economic factors in personal exposures and have applications in environmental risk assessment and household air pollution mitigation in Bhutan.
Do improved biomass cookstoves reduce fuelwood consumption and carbon emissions? evidence from rural Ethiopia using a randomized treatment trial with electronic monitoring, 2015. World Bank.
Authors: Beyene, Abebe; Bluffstone, Randy; et al.
This paper uses a randomized experimental design with real-time electronic stove temperature measurements and controlled cooking tests to estimate the fuelwood and carbon dioxide savings from an improved cookstove program in the process of being implemented in rural Ethiopia. Knowing more about how households interact with improved cookstoves is important, because cooking uses a majority of the fuelwood in the country and therefore is an important determinant of greenhouse gas emissions and indoor air pollution.
Creating local networks among stove users generally appears to increase fuelwood savings, and among monetary treatments the most robust positive effects come from free distribution. The paper estimates that on average one improved stove saves approximately 634 kilograms of fuelwood per year or about 0.94 tons of carbon dioxide equivalent per year, which is about half of previous estimates. Using the May 2015 California auction price of $13.39/ton, the carbon sequestration from each stove deployed is worth about $12.59. Such carbon market offset revenues would be sufficient to cover the cost of the stove within one year.
Microgasification cookstoves and pellet fuels from waste biomass: A cost and performance comparison with charcoal and natural gas in Tanzania. African Jnl Sci & Tech, June 2015.
Authors: Don Lotter, Nathan Hunter, Mary Straub, David Msola
Cooking with wood and wood charcoal is done by over 90% of Africa’s population; it has two major challenges: deforestation and indoor air pollution from cooking smoke, the latter being the top risk factor for disease in Tanzania. Microgasification stoves (top lit up draft [TLUD]) that burn pellets produced from agricultural waste have potential to address both of these issues. We examined the relative efficiency and cost of the major urban cooking fuels – charcoal and liquefied natural gas (LNG) – and compared them to cooking with waste biomass-based pellet fuels; we also compared the performance of three models of natural draft (ND) TLUD stove (Troika, Jiko Bomba, St. John’s) and one forced air (fan) stove (Philips).
The Philips and averaged ND stoves used 83 and 133% more pellets by weight respectively to cook beans than charcoal, costing 47 and 93% more at 2013 charcoal and pellet prices. Cooking with LNG costs 387 to 647% more than cooking with charcoal, depending on gas flow rate. The high cost of LNG and LNG stoves will be barriers to the great majority of Tanzanians to move to this improved cookstove technologies (ICTs). Biochar production averaged 59 and 29% of total fuel in the ND and Philips, respectively.
Interviews of 30 ND TLUD stove users showed that 60% abandoned use within one month, 80% stating that they produce too much smoke and 40% stating that controlling the air vent is too much trouble. Seventy five percent said that the TLUD cooks significantly faster than charcoal. Due to the continued 33-99% annual increase in charcoal prices in Tanzania, work on introducing TLUD stoves is justified.
Public health impacts of ecosystem change in the Brazilian Amazon. PNAS, June 2015.
Authors: Simone C. Bauch, Anna M. Birkenbach, Subhrendu K. Pattanayak,1, and Erin O. Sills
The claim that nature delivers health benefits rests on a thin empirical evidence base. Even less evidence exists on how specific conservationpolicies affect multiple health outcomes. We address these gaps in knowledge by combining municipal-level panel data on diseases,public health services, climatic factors, demographics, conservation policies, and other drivers of land-use change in the Brazilian Amazon.
To fully exploit this dataset, we estimate random-effects and quantile regression models of disease incidence. We find that malaria, acute respiratory infection (ARI), and diarrhea incidence are significantly and negatively correlated with the area under strict environmental protection. Results vary by disease for other types of protected areas(PAs), roads, and mining. The relationships between diseases and land-use change drivers also vary by quantile of the disease distribution. Conservation scenarios based on estimated regression results suggest that malaria, ARI, and diarrhea incidence would be reduced by expanding strict PAs, and malaria could be further reduced by restricting roads and mining.
Behavior Change Approaches To Facilitate Clean Cooking and Reduced HAP, 2015. Julia Rosenbaum, WASHplus; FHI 360.
A presentation at the Behavior Change for Clean Cooking: Current Knowledge and Next Steps Seminar, Washington DC, April 2015.
The revolution from the kitchen: Social processes of the removal of traditional cookstoves in Himachal Pradesh, India. Energy for Sustainable Development, August 2015.
Authors: Yiting Wang, , Robert Bailis
Highlights
• We examine social processes of cookstove adoption and displacement in Northern India.
• By subsidizing and reducing logistical barriers, local NGO improved access to LPG.
• Lower caste households remove traditional stoves more readily than higher castes.
• We analyze triggers and drivers propelling changes in kitchen.
• Desire for cleanliness and social identity shape stove choices.
Despite decades of effort, widespread adoption and long-term use of improved cookstoves in developing countries remain hard to achieve. Conventional energy transition models emphasize households’ socio-economic improvement as the most important driver of energy transition. However, previous work has shown households’ continued use of old cookstoves or fuels even when adopting new technologies. Through a case study in India, this paper highlights the socio-political processes of the permanent removal of the traditional chulha cookstove. Newly available liquefied petroleum gas stoves and improved biomass stoves, thought to be substitutes for chulha, lead to different adoption pathways for lower and higher caste households. Lower caste households seem to remove chulha more readily because of sensitivity to chulha’s heavy smoke that pollutes their utensils, kitchen, and clothes. We posit that by adopting cleaner stoves and removing traditional ones, the marginalized can disassociate themselves from practices that perpetuate their social stigma.
The Improved Biomass Stove Saves Wood, But How Often Do People Use It? Evidence from a Randomized Treatment Trial in Ethiopia. World Bank.
Authors: Abebe D. Beyene, Randall Bluffstone, et al.
This paper uses a randomized experimental design and real-time electronic stove use monitors to evaluate the frequency with which villagers use improved biomass-burning Mirt injera cookstoves in rural Ethiopia. Understanding whether, how much, and why improved cookstoves are used is important, because use of the improved stove is a critical determinant of indoor air pollution reductions, and reduced greenhouse gas emissions due to lower fuelwood consumption. Confirming use is, for example, a critical aspect of crediting improved cookstoves’ climate change benefits under the United Nations Reducing Emissions from Deforestation and Forest Degradation Programme.
The paper finds that Ethiopian households in the study area do use the Mirt stove on a regular basis, taking into account regional differences in cooking patterns. In general, stove users also use their Mirt stoves more frequently over time. Giving the Mirt stove away for free and supporting community-level user networks are estimated to lead to more use. The study found no evidence, however, that stove recipients use the stoves more if they have to pay for them, a hypothesis that frequently arises in policy arenas and has also been examined in the literature.
