Indoor Air Quality Updates
Quantitative Guidance for Stove Usage and Performance to Achieve Health and Environmental Targets. Env Health Perspec, March 2015.
Authors: Michael A. Johnson and Ranyee A. Chiang
Background: Displacing the use of polluting and inefficient cookstoves in developing countries is necessary to achieve the potential health and environmental benefits sought through clean cooking solutions. Yet little quantitative context has been provided on how much displacement of traditional technologies is needed to achieve targets for household air pollutant concentrations or fuel savings.
Objectives: This paper provides instructive guidance on the usage of cooking technologies required to achieve health and environmental improvements.
Methods: We evaluate different scenarios of displacement of traditional stoves with use of higher performing technologies. The air quality and fuel consumption impacts were estimated for these scenarios using a single zone box model of indoor air quality and ratios of thermal efficiency. Results: Stove performance and usage must be considered together, as lower performing stoves can result in similar or greater fuel savings than a higher performing stove if the lower performing stove has considerably higher displacement of the baseline stove. Similarly, based on the indoor air quality model, there are multiple performance-usage scenarios for achieving modest indoor air quality improvements. To meet World Health Organization targets, three-stone-fire and basic charcoal stove usage must be nearly eliminated to achieve the particulate matter target (<1-3 hours per week), and substantially limited to meet the carbon monoxide (<7-9 hours per week).
Conclusions: Moderate health gains may be achieved with various performance-usage scenarios. The greatest benefits are estimated to be achieved by near complete displacement of traditional stoves with clean technologies, emphasizing the need to shift in the long term to near exclusive use of clean fuels and stoves. The performance-usage scenarios are also provided as a tool to guide technology selection and prioritize behavior change opportunities to maximize impact.
BMJ Editorial: Air pollution, stroke, and anxiety. British Medical Journal, March 24, 2015.
Author: Michael Brauer, professor
Particulate air pollution is an emerging risk factor for an increasing number of common conditions
The effects of air pollution on the lungs and heart are now widely appreciated, with expanding evidence for an important role in cardiac disease.1 The Global Burden of Disease Study identified fine particulate matter (PM2.5) in outdoor air and household air pollution from use of solid fuels as the ninth and fourth leading risk factors, respectively, for disease worldwide,2 and the World Health Organization attributes one in every eight deaths to air pollution.3 The effects of air pollution are not limited to cardiopulmonary diseases. Recent evidence suggests a role in diverse outcomes, including diabetes,4 low birth weight, and preterm birth.5 This research stems from improved understanding of the role of air pollution in initiating systemic inflammation, a response that may affect multiple organ systems. Two linked studies (doi:10.1136/bmj.h1295, doi:10.1136/bmj.h1111) add to growing evidence that air pollution is an important risk factor for an increasing number of common diseases.6 7
In the first of the two papers, Shah and colleagues6 systematically reviewed and meta-analysed 103 studies conducted in 28 countries and including 6.2 million events to assess the role of short term fluctuations in air pollution as a trigger for stroke. Although evidence from several cohort studies of long term exposure to particulate matter indicates associations with stroke mortality, such findings are not universal.8
The role of air pollution as a possible trigger for stroke has important implications for disease burden, especially in China where air pollution and the incidence of (especially haemorrhagic) stroke are high. In their analysis, Shah and colleagues found that increases in each of the common gaseous and particulate air pollutants were significantly associated with admission to hospital for stroke or stroke related mortality, with associations strongest for strokes on the same day as exposure; increased ozone was only weakly associated with cerebrovascular events.
Air pollution remained significantly associated with stroke in sensitivity analyses that adjusted for potential biases related to quality of outcome ascertainment, assessment of exposure, and adjustment for confounders. This analysis supports a role for air pollution as a modifiable risk factor for stroke, although associations with air pollution were less precise for haemorrhagic stroke than for ischaemic stroke. The impact of chronic exposure to air pollution on development of carotid atherosclerosis (a precursor for stroke) remains unclear. Although this is not covered in the analysis, evidence of an association is growing.9
Since air pollution causes systemic inflammation, it is reasonable that researchers have now turned to the arena of mental health, a leading priority for research given the relative absence of known modifiable risk factors and a high and growing disease burden.10 In the second linked paper, Power and colleagues exploit rich data in the Nurse’s Health Study cohort to assess the role of particulate pollution on prevalent anxiety symptoms.7 They found an exposure dependent association between higher levels of PM2.5 and increased symptoms of anxiety, and indications that associations were stronger for exposures in the month immediately preceding the scoring of anxiety.
These observations were supported by several sensitivity analyses, which indicated that associations were robust to broad geographical region, health status (to control for the possibility of anxiety as a sequela of cardiopulmonary effects of air pollution), and demographic characteristics, although the study was limited to older women. Power and colleagues’ findings add to a growing literature on the mental health effects of air pollution, including a small but intriguing body of research linking short term variability in air pollution to suicide.11
Power and colleagues used spatiotemporal exposure estimates and reported stronger effects for more recent exposures, reducing confounding by spatially varying factors correlated with air pollution. Since effects were observed over all time periods, spatial variation seems to have had an important influence on effect estimates. Furthermore, although effects were observed in all geographical regions, the investigators did not examine other potentially adverse (for example, noise, barometric pressure, solar intensity) or healthy (for example, natural spaces) environmental exposures that may operate at different scales. Indeed, evidence is accumulating that natural spaces may have beneficial effects on stress and social cohesion, both of which deserve further study in relation to mental health.12
As with any observational study, questions remain, as the authors acknowledge, and the findings should be replicated in other populations and with other study designs. Moreover, although these observations are biologically plausible, given links between inflammation and anxiety there is a need for greater mechanistic supporting evidence, of the type that now exists for associations between particulate matter and pulmonary, cardiac, and circulatory disease.
The findings of these two studies support a sharper focus on air pollution as a leading global health concern. They also suggest opportunities for reducing the prevalence of two debilitating and common diseases. One of the unique features of air pollution as a risk factor for disease is that exposure to air pollution is almost universal. While this is a primary reason for the large disease burden attributable to outdoor air pollution, it also follows that even modest reductions in pollution could have widespread benefits throughout populations. The two linked papers in this issue confirm the urgent need to manage air pollution globally as a cause of ill health and offer the promise that reducing pollution could be a cost effective way to reduce the large burden of disease from both stroke and poor mental health.
How Cookstoves Research is Changing the World | Source: American Thoracic Society News, March 2015.
Three billion people in the world, a number unchanged in nearly 30 years, cook their food with an open fire, causing respiratory problems such as pneumonia in children and COPD and lung cancer in adults, as well as cardiovascular diseases. Estimates in 2012 from the Global Burden of Disease project, indicate that smoke from these traditional cooking methods causes a staggering four million premature deaths each year.
Until the last decade, this major health issue had gone largely unnoticed by most medical scientists and public health experts. ATS members, in collaboration with organizations, government officials, and institutions across the world, have played important roles in describing the health impacts of cook smoke, conducting clinical trials with cleaner-burning biomass stoves, and highlighting gaps in knowledge of the problem. In recent months, their efforts have gained momentum.
Their findings have contributed to the publication of the World Health Organization’s Indoor Air Quality Guidelines, a report on childhood pneumonia from the Institute of Health Metrics and Evaluation, and a Lancet Respiratory Household Air Pollution (HAP) Commission.
- Read the complete article.
Kodros, Jack CSU Global Modeling and Climate Effects (PDF) (40 pp, 3.87 MB) Smith, Kirk SOMAARTH -I Demographic Development and Environment Surveillance Site (DDESS) (PDF) (20 pp, 4.2 MB) Smith, Kirk Household/Outdoor Pollution in India: EPA STAR Grant (PDF) (45 pp, 3.91 MB) Volckens, John
Pierce, Jeff Quantifying the Climate, Air Quality, and Health Benefits of Improved Cookstoves: An Integrated Laboratory, Field and Modeling Study (PDF) (17 pp, 1.33 MB) Birnbaum, Linda Assessing Exposures and Health Effects Related to Indoor Biomass Fuel Burning (PDF) (13 pp, 1.2 MB) Mehta Sumi Phase 2 Research and Evaluation Roadmap Public Health, Environment, and Climate (PDF) (18 pp, 5.23 MB) Sage, Mike
Yip, Fuyuen Evaluation of Acceptability and Performance of Stove Options for Reducing Household Air Pollution in Rural West Kenya (PDF) (26 pp, 3.18 MB)
Sustainable diffusion of sustainable technologies? An entrepreneur-led initiative to promote improved cookstoves in rural western Kenya
Sustainable diffusion of sustainable technologies? An entrepreneur-led initiative to promote improved cookstoves in rural western Kenya. Sustainability: Science, Practice, & Policy, Spring 2015.
Authors: Barry Ness & Ann Åkerman, Lund University Centre for Sustainability Studies, PO Box 170, Lund, 22100 Sweden (email: firstname.lastname@example.org; email@example.com)
This article presents the accomplishments and challenges of a rural sustainable development initiative in Nyanza Province, Kenya. Our focus is on the sale and financing of a simple technology—an improved cookstove—by a local entrepreneur. The theoretical basis of the research is innovation systems and (social) entrepreneurship. We first define the major challenges of the diffusion process encountered throughout the initiative’s early years, with special concentration on maintaining the working capital to sell and finance additional innovations.
We next present the measures to address the challenge, including detailed written contracts, a modest fee for late payments, a contractsigning witness, and money-transfer options by mobile telephone. We subsequently present repayment rates for up to one year after implementing the changes, which show a general pattern of improvement. Finally, we discuss the sustainability of the technology, repayment rates, innovation systems, and entrepreneurship in sub-Saharan Africa. The main message of the research is that the major challenge is not creating more sustainable technologies, but overcoming difficulties in diffusion processes.
Household air pollution and cancers other than lung: a meta-analysis. Environmental Health, Mar 2015.
Authors: Sowmya Josyula (firstname.lastname@example.org)Juan Lin (email@example.com), et al.
Household air pollution (HAP) from solid fuel combustion contributes to 2.6% of the global burden of disease. HAP emissions are an established lung carcinogen; however, associations with other cancer sites have not been fully explored. We conducted a meta-analysis of 18 case–control studies. Using fixed-effects models, utilizing the adjusted odds ratios (OR) and 95% confidence intervals (95% CI) from each study, we evaluated the association between HAP and cervical neoplasia (663 cases and 1747 controls) and upper aero-digestive tract cancers (6022 cases and 15 325 controls).
We found that HAP was associated with cervical neoplasia (OR = 6.45; 95%CI = 3.12-13.35; 4 studies); oral (OR = 2.54; 95% CI = 1.92-3.34; 4 studies; 1000 cases /3450 controls); nasopharyngeal (OR = 1.80; 95%CI = 1.26-2.28; 6 studies; 2231 cases/2160 controls); pharyngeal (OR = 3.56; 95%CI = 2.22-5.70; 4 studies; 1036 cases/3746 controls); and laryngeal (OR = 2.34; 95% CI = 1.71- 3.20; 5 studies; 1416 cases/4514 controls) cancers. The elevated risk for esophageal cancer (OR = 1.92; 95%CI = 0.82-4.48; 2 studies; 339 cases/1455 controls) was non-significant.
HAP was associated with cervical neoplasia among studies that accounted for HPV infection (OR = 9.60; 95%CI = 3.79-24.32) and smoking (OR = 4.72; 95%CI = 1.84-12.07). Similarly, our observed associations between HAP and upper aero-digestive tract cancers remained significantly elevated when analyses were restricted to studies that controlled for smoking. No significant publication bias was detected. Our results suggest that the carcinogenic effect of HAP observed for lung cancer may extend to other cancers, including those of the cervix and the upper aero-digestive tract. Further research is needed to confirm these associations in prospective studies.
Prevalence of chronic obstructive pulmonary disease and variation in risk factors across four geographically diverse resource-limited settings in Peru
Prevalence of chronic obstructive pulmonary disease and variation in risk factors across four geographically diverse resource-limited settings in Peru. Respiratory Research, Feb 2015,
Authors, Devan Jaganath (firstname.lastname@example.org)J Jaime Miranda (email@example.com), et al.
Background – It is unclear how geographic and social diversity affects the prevalence of chronic obstructive pulmonary disease (COPD). We sought to characterize the prevalence of COPD and identify risk factors across four settings in Peru with varying degrees of urbanization, altitude, and biomass fuel use.
Methods – We collected sociodemographics, clinical history, and post-bronchodilator spirometry in a randomly selected, age-, sex- and site-stratified, population-based sample of 2,957 adults aged ≥35 years (median age was 54.8 years and 49.3% were men) from four resource-poor settings: Lima, Tumbes, urban and rural Puno. We defined COPD as a post-bronchodilator FEV1/FVC < 70%.
Results – Overall prevalence of COPD was 6.0% (95% CI 5.1%–6.8%) but with marked variation across sites: 3.6% in semi-urban Tumbes, 6.1% in urban Puno, 6.2% in Lima, and 9.9% in rural Puno (p < 0.001). Population attributable risks (PARs) of COPD due to smoking ≥10 pack-years were less than 10% for all sites, consistent with a low prevalence of daily smoking(3.3%). Rather, we found that PARs of COPD varied by setting. In Lima, for example, thehighest PARs were attributed to post-treatment tuberculosis (16% and 22% for men andwomen, respectively). In rural Puno, daily biomass fuel for cooking among women wasassociated with COPD (prevalence ratio 2.22, 95% CI 1.02–4.81) and the PAR of COPD dueto daily exposure to biomass fuel smoke was 55%.
Conclusions – The burden of COPD in Peru was not uniform and, unlike other settings, was not predominantly explained by tobacco smoking. This study emphasizes the role of biomass fuel use, and highlights pulmonary tuberculosis as an often neglected risk factor in endemic areas
Does household use of biomass fuel cause lung cancer? A systematic review and evaluation of the evidence for the GBD 2010 study
Does household use of biomass fuel cause lung cancer? A systematic review and evaluation of the evidence for the GBD 2010 study. Thorax, March 2015.
Authors: Nigel Bruce1, Mukesh Dherani1, Rui Liu2, H Dean Hosgood III3,4, Amir Sapkota5, Kirk R Smith2, Kurt Straif6, Qing Lan3, Daniel Pope1
+ Author Affiliations
1Department of Public Health and Policy, University of Liverpool, Liverpool, UK
2Environmental Health Sciences, School of Public Health, University of California Berkeley, California, USA
3Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
4Division of Epidemiology, Albert Einstein College of Medicine, Bronx, New York, USA
5Maryland Institute for Applied Environmental Health, University of Maryland, School of Public Health, College Park, Maryland, USA
6International Agency for Research on Cancer, Lyon, France
Correspondence to: Dr Nigel G Bruce, Department of Public Health and Policy, University of Liverpool, Whelan Building, Quadrangle, Liverpool L69 3GB, UK; firstname.lastname@example.org
Background – Around 2.4 billion people use traditional biomass fuels for household cooking or heating. In 2006, the International Agency for Research on Cancer (IARC) concluded emissions from household coal combustion are a Group 1 carcinogen, while those from biomass were categorised as 2A due to epidemiologic limitations. This review updates the epidemiologic evidence and provides risk estimates for the 2010 Global Burden of Disease study.
Methods – Searches were conducted of 10 databases to July 2012 for studies of clinically diagnosed or pathologically confirmed lung cancer associated with household biomass use for cooking and/or heating.
Findings – Fourteen eligible studies of biomass cooking or heating were identified: 13 had independent estimates (12 cooking only), all were case-control designs and provided 8221 cases and 11 342 controls. The ORs for lung cancer risk with biomass for cooking and/or heating were OR 1.17 (95% CI 1.01 to 1.37) overall, and 1.15 (95% CI 0.97 to 1.37) for cooking only. Publication bias was not detected, but more than half the studies did not explicitly describe a clean reference category. Sensitivity analyses restricted to studies with adequate adjustment and a clean reference category found ORs of 1.21 (95% CI 1.05 to 1.39) for men (two reports, compiling five studies) and 1.95 (95% CI 1.16 to 3.27) for women (five reports, compiling eight studies). Exposure–response evidence was seen for men, and higher risk for women in developing compared with developed countries, consistent with higher exposures in the former.
Conclusions – There is now stronger evidence for biomass fuel use causing lung cancer, but future studies need better exposure assessment to strengthen exposure–response evidence.
Characterization of biomass burning emissions from cooking fires, peat, crop residue, and other fuels with high-resolution proton-transfer-reaction time-of-flight mass spectrometry
Characterization of biomass burning emissions from cooking fires, peat, crop residue, and other fuels with high-resolution proton-transfer-reaction time-of-flight mass spectrometry. Atmos. Chem. Phys., 15, 845–865, 2015.
Authors: C. E. Stockwell1, P. R. Veres2,3, J. Williams4, and R. J. Yokelson1
1University of Montana, Department of Chemistry, Missoula, MT, USA
2Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
3Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and
Atmospheric Administration, Boulder, CO, USA
4Max Planck Institute for Chemistry, Atmospheric Chemistry Department, 55128 Mainz, Germany
Correspondence to: R. J. Yokelson (email@example.com)
We deployed a high-resolution proton-transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) to measure biomass-burning emissions from peat, crop residue,cooking fires, and many other fire types during the fourth FireLab at Missoula Experiment (FLAME-4) laboratory campaign.A combination of gas standard calibrations and composition sensitive, mass-dependent calibration curves was applied to quantify gas-phase non-methane organic compounds(NMOCs) observed in the complex mixture of fire emissions. We used several approaches to assign the best identities to most major “exact masses”, including many high molecular mass species. Using these methods, approximately 80–96 % of the total NMOC mass detected by the PTR-TOFMSand Fourier transform infrared (FTIR) spectroscopy was positively or tentatively identified for major fuel types.
We report data for many rarely measured or previously unmeasured emissions in several compound classes including aromatic hydrocarbons, phenolic compounds, and furans; many of these are suspected secondary organic aerosol precursors.A large set of new emission factors (EFs) for a range of globally significant biomass fuels is presented. Measurements show that oxygenated NMOCs accounted for the largest fraction of emissions of all compound classes. In a brief studyof various traditional and advanced cooking methods, the EFs for these emissions groups were greatest for open three stone cooking in comparison to their more advanced counterparts. Several little-studied nitrogen-containing organic compounds were detected from many fuel types, that together accounted for 0.1–8.7 % of the fuel nitrogen, and some may play a role in new particle formation.
Innovating Energy Access for Remote Areas: Discovering Untapped Resources: Proceedings, 2014.
Martina Schäfer | Daniel Kammen | Noara Kebir | Daniel Philipp (editors)
Some of the papers in the proceedings are:
- The influence of the end user’s context on the dissemination of domestic biogas systems in developing countries
- Scale vs. Substance? Lessons from a Context-responsive Approach to Market-based Stove Development in Western Kenya
- Feasibility study assessing the impact of biogas digesters on indoor air pollution in households in Uganda
- How to Scale Up Green Microfinance? A Comparative Study of Energy Lending in Peru
- Microfinancing decentralized solar energy systems in India: Innovative products through group approach
- Innovative Energy Access for Remote Areas – “The LUAV-Light Up a Village” project
Relationship Between Daily Exposure to Biomass Fuel Smoke and Blood Pressure in High-Altitude Peru. Hypertension, Mar 2015.
Authors: Melissa Burroughs Peña, Karina M. Romero, Eric J. Velazquez, Victor G. Davila-Roman, Robert H. Gilman, Robert A. Wise, J. Jaime Miranda, William Checkley
Correspondence to William Checkley, Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University, 1800 Orleans St, Suite 9121, Baltimore, MD 21205.
Household air pollution from biomass fuel use affects 3 billion people worldwide; however, few studies have examined the relationship between biomass fuel use and blood pressure. We sought to determine if daily biomass fuel use was associated with elevated blood pressure in high altitude Peru and if this relationship was affected by lung function. We analyzed baseline information from a population-based cohort study of adults aged ≥35 years in Puno, Peru. Daily biomass fuel use was self-reported. We used multivariable regression models to examine the relationship between daily exposure to biomass fuel smoke and blood pressure outcomes. Interactions with sex and quartiles of forced vital capacity were conducted to evaluate for effect modification. Data from 1004 individuals (mean age, 55.3 years; 51.7% women) were included.
We found an association between biomass fuel use with both prehypertension (adjusted relative risk ratio, 5.0; 95% confidence interval, 2.6–9.9) and hypertension (adjusted relative risk ratio, 3.5; 95% confidence interval, 1.7–7.0). Biomass fuel users had a higher systolic blood pressure (7.0 mm Hg; 95% confidence interval, 4.4–9.6) and a higher diastolic blood pressure (5.9 mm Hg; 95% confidence interval, 4.2–7.6) when compared with nonusers. We did not find interaction effects between daily biomass fuel use and sex or percent predicted forced vital capacity for either systolic blood pressure or diastolic blood pressure. Biomass fuel use was associated with a higher likelihood of having hypertension and higher blood pressure in Peru. Reducing exposure to household air pollution from biomass fuel use represents an opportunity for cardiovascular prevention.
Effectiveness of interventions to reduce indoor air pollution and/or improve health in homes using solid fuel in lower and middle income countries: protocol for a systematic review
Effectiveness of interventions to reduce indoor air pollution and/or improve health in homes using solid fuel in lower and middle income countries: protocol for a systematic review. Systematic Reviews, March 2015, 4:22 doi:10.1186/s13643-015-0012-8
Authors: Reginald Quansah, Caroline A Ochieng, Sean Semple, Sanjar Juvekar, Jacques Emina, Frederick Ato Armah and Isaac Luginaah
Background – Indoor air pollution (IAP) interventions are widely promoted as a means of reducing indoor air pollution/health from solid fuel use; and research addressing impact of these interventions has increased substantially in the past two decades. It is timely and important to understand more about effectiveness of these interventions. We describe the protocol of a systematic review to (i) evaluate effectiveness of IAP interventions to improve indoor air quality and/or health in homes using solid fuel for cooking and/or heating in lower- and middle-income countries, (ii) identify the most effective intervention to improve indoor air quality and/or health, and (iii) identify future research needs.
Methods – This review will be conducted according to the National Institute for Health and Care Excellence (NICE) guidelines and will be reported following the PRISMA statement. Ovid MEDLINE, Ovid Embase, SCOPUS, and PubMed searches were conducted in September 2013 and updated in November 2014 (and include any further search updates in February 2015). Additional references will be located through searching the references cited by identified studies and through the World Health Organization Global database of household air pollution measurements. We will also search our own archives. Data extraction and risk of bias assessment of all included papers will be conducted independently by five reviewers.
Discussion – The study will provide insights into what interventions are most effective in reducing indoor air pollution and/or adverse health outcomes in homes using solid fuel for cooking or heating in lower- or middle-income countries. The findings from this review will be used to inform future IAP interventions and policy on poverty reduction and health improvement in poor communities who rely on biomass and solid fuels for cooking and heating.
WHO indoor air quality guidelines on household fuel combustion: Strategy implications of new evidence on interventions and exposure–risk functions
WHO indoor air quality guidelines on household fuel combustion: Strategy implications of new evidence on interventions and exposure–risk functions. Atmospheric Environment, April 2015.
Authors: Nigel Bruce, Dan Pope, Eva Rehfuess, Kalpana Balakrishnan, Heather Adair-Rohani, Carlos Dora
- New WHO air quality guidelines will address household air pollution (HAP).
- Action on HAP could lower risk of multiple child and adult diseases by 20–50%.
- New evidence shows levels at or below 35 μg/m3 PM2.5 (WHO IT-1) are needed.
- Most improved solid fuel stoves result in PM2.5 levels well above IT-1.
- Intervention strategy must shift towards accelerating access to clean fuels.
Background: 2.8 billion people use solid fuels as their primary cooking fuel; the resulting high levels of household air pollution (HAP) were estimated to cause more than 4 million premature deaths in 2012. The people most affected are among the world’s poorest, and past experience has shown that securing adoption and sustained use of effective, low-emission stove technologies and fuels in such populations is not easy. Among the questions raised by these challenges are (i) to what levels does HAP exposure need to be reduced in order to ensure that substantial health benefits are achieved, and (ii) what intervention technologies and fuels can achieve the required levels of HAP in practice? New WHO air quality guidelines are being developed to address these issues.
Aims: To address the above questions drawing on evidence from new evidence reviews conducted for the WHO guidelines.
Methods: Discussion of key findings from reviews covering (i) systematic reviews of health risks from HAP exposure, (ii) newly developed exposure–response functions which combine combustion pollution risk evidence from ambient air pollution, second-hand smoke, HAP and active smoking, and (iii) a systematic review of the impacts of solid fuel and clean fuel interventions on kitchen levels of, and personal exposure to, PM2.5 and carbon monoxide (CO).
Findings: Evidence on health risks from HAP suggest that controlling this exposure could reduce the risk of multiple child and adult health outcomes by 20–50%. The new integrated exposure–response functions (IERs) indicate that in order to secure these benefits, HAP levels require to be reduced to the WHO IT-1 annual average level (35 μg/m3 PM2.5), or below. The second review found that, in practice, solid fuel ‘improved stoves’ led to large percentage and absolute reductions, but post-intervention kitchen levels were still very high, at several hundreds of μg/m3 of PM2.5, although most solid fuel stove types met the WHO 24-hr average guideline for CO of 7 mg/m3. Clean fuel user studies were few, but also did not meet IT-1 for PM2.5, likely due to a combination of continuing multiple stove and fuel use, other sources in the home (e.g. kerosene lamps), and pollution from neighbours and other outdoor sources.
Conclusions: Together, this evidence implies there needs to be a strategic shift towards more rapid and widespread promotion of clean fuels, along with efforts to encourage more exclusive use and control other sources in and around the home. For households continuing to rely on solid fuels, the best possible low-emission solid fuel stoves should be promoted, backed up by testing and in-field evaluation.
Reductions in Indoor Black Carbon Concentrations from Improved Biomass Stoves in Rural India. Environ Sci Technol. 2015 Mar 4.
Authors: Patange OS, Ramanathan N, Rehman H, Tripathi SN, Misra A, Kar A, Graham E, Singh L, Bahadur R, Ramanathan V.
Deployment of improved biomass burning cookstoves is recognized as a black carbon (BC) mitigation measure that has the potential to achieve health benefits and climate co-benefits. Yet, few field based studies document BC concentration reductions (and resulting human exposure) resulting from improved stove usage. In this paper, data are presented from 277 real-world cooking sessions collected during two field studies to document the impacts on indoor BC concentrations inside village kitchens as a result of switching from traditional stoves to improved forced draft (FD) stoves. Data collection utilized new low-cost cellphone methods to monitor BC, cooking duration, and fuel consumption.
A cross sectional study recorded a reduction of 36% in BC during cooking sessions. An independent paired sample study demonstrated a statistically significant reduction of 40% in 24-hour BC concentrations when traditional stoves were replaced with FD stoves. Reductions observed in these field studies differ from emission factor reductions (up to 99%) observed under controlled conditions in laboratory studies. Other non-stove sources (e.g. kerosene lamps, ambient concentrations) likely offset the reductions. Health exposure studies should utilize reductions determined by field measurements inside village kitchens, in conjunction with laboratory data, to assess the health impacts of new cooking technologies.
The effect of exposure to wood smoke on outcomes of childhood pneumonia in Botswana. Source: The International Journal of Tuberculosis and Lung Disease, March 2015.
Authors: Kelly, M. S.; Wirth, K. E. et al.
SETTING: Tertiary hospital in Gaborone, Botswana.
OBJECTIVE: To examine whether exposure to wood smoke worsens outcomes of childhood pneumonia.
DESIGN: Prospective cohort study of children aged 1–23 months meeting clinical criteria for pneumonia. Household use of wood as a cooking fuel was assessed during a face-to-face questionnaire with care givers. We estimated crude and adjusted risk ratios (RRs) and 95% confidence intervals (CIs) for treatment failure at 48 h by household use of wood as a cooking fuel. We assessed for effect modification by age (1–5 vs. 6–23 months) and malnutrition (none vs. moderate vs. severe).
RESULTS: The median age of the 284 enrolled children was 5.9 months; 17% had moderate or severe malnutrition. Ninety-nine (35%) children failed treatment at 48 h and 17 (6%) died. In multivariable analyses, household use of wood as a cooking fuel increased the risk of treatment failure at 48 h (RR 1.44, 95%CI 1.09–1.92, P = 0.01). This association differed by child nutritional status (P = 0.02), with a detrimental effect observed only among children with no or moderate malnutrition.
CONCLUSIONS: Exposure to wood smoke worsens outcomes for childhood pneumonia. Efforts to prevent exposure to smoke from unprocessed fuels may improve pneumonia outcomes among children.
Children’s Health in Latin America: The Influence of Environmental Exposures. Environ Health Perspect, March 2015, DOI:10.1289/ehp.1408292
Authors: Amalia Laborde, Fernando Tomasina, et al.
Specific Environmental Health Threats to Children in Latin America
Indoor air pollution. Indoor air pollution is the leading environmental threat to health in the Americas, being responsible for nearly 5% of healthy years of life lost and 7% of premature deaths (WHO 2014c). WHO estimates that in 2012, 7,500 deaths were attributable to indoor air pollution in children < 5 years of age in low- and middle-income countries of the Americas (WHO 2014c). In 2010, indoor air pollution ranked eighth among risk factors for chronic disease in Latin America (Lim et al. 2012).
Solid and biomass fuels are the major source of indoor air pollution, especially in rural areas. WHO estimates that in 2010, 10% of the population of Latin America relied on solid and biomass fuels for cooking and heating, largely in open fires or unvented stoves (WHO 2014b). The rural/urban ratio in use of solid fuels is 2.3 in countries in the lowest and, 11.7 in the highest quartile of the Human Development Index (http://hdr.undp.org/en/content/human-development-index-hdi). The Living Standards Measurement Survey (World Bank 2012) conducted in Guatemala demonstrated the highest reliance on solid fuel—up to 95% in some regions—among indigenous populations in rural areas.
Ten-fold disparities in death rates attributable to indoor air pollution are seen across Latin American countries and range from a high of 14 in the least developed countries, down to 0.3 for high-income countries (WHO 2014b). Thus in 2012, ≥ 50% of the populations of Guatemala, Haiti, Honduras, and Nicaragua used solid fuels as their main energy source (WHO 2014b). Even in urban areas of the less-developed countries of the Americas, a high percentage of the population relies on solid fuels (Soares da Silva et al. 2013; WHO 2014b).
Since 1990 the region has experienced a steady decline in the percentage of the population using solid fuels and the size of the population exposed (Bonjour et al. 2013). Some countries can make the transition to cleaner fuels, but others will likely continue to use solid fuels because of lack of infrastructure and the high costs associated with transition to gas and electricity.
Interventions are underway, especially in areas of the Americas, to introduce new cookstoves that use solid fuels more efficiently and are less polluting. A major study of this intervention in Guatemala found that using clean stoves was associated with a 30% reduction in severe pneumonia among children < 18 months of age (Smith et al. 2011). A study in Peru found that using the new cookstoves significantly reduced sleep and respiratory symptoms in children 2–14 years of age, but only in households that used the less-polluting stoves exclusively and with adequate maintenance (Accinelli et al. 2014).
Patterns of Stove Use in the Context of Fuel–Device Stacking: Rationale and Implications. EcoHealth, February 2015
Authors: Ilse Ruiz-Mercado, Omar MaseraIn this paper we explain that stacking and, specifically, the residual use of traditional fires have strong implications for two agendas critical to the cookstove sector: the implementation of fuel-stove programs that deliver tangible and sustained benefits and the design of evaluation and monitoring schemes that effectively and realistically assess these benefits. The rationale and implications of stacking hinge on three key aspects: end uses, cooking tasks and livelihood strategies. For example, traditional fires satisfy energy uses that extend beyond cooking and therefore, most of the times, introducing a single clean fuel-stove will not be a perfect substitution of the traditional fires and their residual use will persist. It is by looking at the interactions of these three aspects with habits, culture, preferences, and household dynamics that the patterns of fuel-stove use can be understood and that the actual benefits from clean fuels and stoves can be assessed. Thus, addressing stacking, displacement and residual use of traditional fires requires that we:
- Move from introducing a single fuel-stove to the promotion of a portfolio or “stack” of options(fuels, stoves and practices) to fully displace the negative health and environmental effects of traditional open fires.
- Design stoves that target the most critical traditional cooking tasks (the most frequent, most culturally relevant or those with the greatest negative effects -not necessarily the same) and stoves specifically aimed at covering residual end uses.
- Evaluate the effects of introducing a clean fuel-device and its levels of usage in terms of the niche of tasks that the stove can actually cover. Characterize the redistribution of tasks among new and existing stoves and consider the weight that each task has (for health, fuel or emissions) to assess the impacts of stacking and displacement.
- Complement fuel-stove dissemination with strategies to provide cost-effective alternatives to fuel processing, storage and drying as well as sustainable mechanisms to secure spare parts and stove repairs.
Abstract: The implementation of clean fuel and stove programs that achieve sustained use and tangible health, environmental, and social benefits to the target populations remains a key challenge. Realization of these benefits has proven elusive because even when the promoted fuels-stoves are used in the long term they are often combined (i.e., “stacked”) with the traditional ones to fulfill all household needs originally met with open fires.
This paper reviews the rationale for stacking in terms of the roles of end uses, cooking tasks, livelihood strategies, and the main patterns of use resulting from them. It uses evidence from case studies in different countries and from a 1-year-long field study conducted in 100 homes in three villages of Central Mexico; outlining key implications for household fuel savings, energy use, and health. We argue for the implementation of portfolios of clean fuels, devices and improved practices tailored to local needs to broaden the use niches that stove programs can cover and to reduce residual open fire use.
This allows to integrate stacking into diagnosis tools, program monitoring, evaluation schemes, and implementation strategies and establish critical actions that researchers and project planners can consider when faced with actual or potential fuel-device stacking.
A Household-Based Study of Contact Networks Relevant for the Spread of Infectious Diseases in the Highlands of Peru
A Household-Based Study of Contact Networks Relevant for the Spread of Infectious Diseases in the Highlands of Peru. PLoS ONE, Mar 2015.
Authors: Carlos G. Grijalva , Nele Goeyvaerts, Hector Verastegui, Kathryn M. Edwards, Ana I. Gil, Claudio F. Lanata, Niel Hens
Background - Few studies have quantified social mixing in remote rural areas of developing countries, where the burden of infectious diseases is usually the highest. Understanding social mixing patterns in those settings is crucial to inform the implementation of strategies for disease prevention and control. We characterized contact and social mixing patterns in rural communities of the Peruvian highlands.
Methods and Findings - This cross-sectional study was nested in a large prospective household-based study of respiratory infections conducted in the province of San Marcos, Cajamarca-Peru. Members of study households were interviewed using a structured questionnaire of social contacts (conversation or physical interaction) experienced during the last 24 hours. We identified 9015 reported contacts from 588 study household members. The median age of respondents was 17 years (interquartile range [IQR] 4–34 years). The median number of reported contacts was 12 (IQR 8–20) whereas the median number of physical (i.e. skin-to-skin) contacts was 8.5 (IQR 5–14). Study participants had contacts mostly with people of similar age, and with their offspring or parents. The number of reported contacts was mainly determined by the participants’ age, household size and occupation. School-aged children had more contacts than other age groups. Within-household reciprocity of contacts reporting declined with household size (range 70%-100%). Ninety percent of household contact networks were complete, and furthermore, household members’ contacts with non-household members showed significant overlap (range 33%-86%), indicating a high degree of contact clustering. A two-level mixing epidemic model was simulated to compare within-household mixing based on observed contact networks and within-household random mixing. No differences in the size or duration of the simulated epidemics were revealed.
Conclusion - This study of rural low-density communities in the highlands of Peru suggests contact patterns are highly assortative. Study findings support the use of within-household homogenous mixing assumptions for epidemic modeling in this setting.
Field Testing of Alternative Cookstove Performance in a Rural Setting of Western India. International Journal of Environmental Research and Public Health, Feb 2015.
Authors: Veena Muralidharan , Thomas E. Sussan, et al.
Nearly three billion people use solid fuels for cooking and heating, which leads to extremely high levels of household air pollution and is a major cause of morbidity and mortality. Many stove manufacturers have developed alternative cookstoves (ACSs) that are aimed at reducing emissions and fuel consumption. Here, we tested a traditional clay chulha cookstove (TCS) and five commercially available ACSs, including both natural draft (Greenway Smart Stove, Envirofit PCS-1) and forced draft stoves (BioLite HomeStove, Philips Woodstove HD4012, and Eco-Chulha XXL), in a test kitchen in a rural village of western India.
Compared to the TCS, the ACSs produced significant reductions in particulate matter less than 2.5 µm (PM2.5) and CO concentrations (Envirofit: 22%/16%, Greenway: 24%/42%, BioLite: 40%/35%, Philips: 66%/55% and Eco-Chulha: 61%/42%), which persisted after normalization for fuel consumption or useful energy. PM2.5 and CO concentrations were lower for forced draft stoves than natural draft stoves. Furthermore, the Philips and Eco-Chulha units exhibited higher cooking efficiency than the TCS. Despite significant reductions in concentrations, all ACSs failed to achieve PM2.5 levels that are considered safe by the World Health Organization.
Consequence of indoor air pollution in rural area of Nepal: a simplified measurement approach. Frontiers in Public Health, Jan 2015.
Authors: Chhabi Lal Ranabhat, Chun-Bae Kim, et al.
People of developing countries especially from rural area are commonly exposed to high levels of household pollution for 3–7 h daily using biomass in their kitchen. Such biomass produces harmful smoke and makes indoor air pollution (IAP). Community-basedcross-sectional study was performed to identify effects of IAP by simplified measurement approach in Sunsari District of Nepal. Representative samples of 157 housewives from household, involving more than 5 years in kitchen were included by cluster sampling. Datawere analyzed by SPSS and logistic regression was applied for the statistical test. Most(87.3%) housewives used biomass as a cooking fuel. Tearing of eyes, difficulty in breathing,and productive cough were the main reported health problems and traditional mudstoves and use of unrefined biomass were statistically significant (p < 0.05) and more risk(AOR > 2) with health problems related to IAP. The treatment cost and episodes of acuterespiratory infection was >2 folders higher in severe IAP than mild IAP. Simplified measurement approach could be helpful to measure IAP in rural area. Some effective intervention is suggested to reduce the severe level of IAP considering women and children.