WHO Indoor air quality guidelines on household fuel combustion: Strategy implications of new evidence on interventions and exposure-risk functions. Atmospheric Environment, 27 August 2014, In Press.

Nigel Brucea, b, , , Dan Popea, Eva Rehfuessc, Kalpana Balakrishnand, Heather Adair-Rohanib, Carlos Dorab
a Department of Public Health and Policy, University of Liverpool, UK
b Department of Public Health, Environmental and Social Determinants of Health, World Health Organisation, Geneva
c Institute for Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-University, Munich, Germany
d Department of Environmental Health Engineering, Sri Ramachandra University, Chennai, India

• 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 forPM2.5, 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.

Highway proximity and black carbon from cookstoves as a risk factor for higher blood pressure in rural China. Proc Natl Acad Sci U S A. 2014 Aug 25.

Baumgartner J1, Zhang Y2, Schauer JJ3, Huang W2, Wang Y2, Ezzati M4.
1Institute for Health and Social Policy and Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada H3A 1A3; Institute on the Environment, University of Minnesota, St. Paul, MN 55108; jill.baumgartner@mcgill.ca.
2College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China;
3Environmental Chemistry and Technology Program, Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706; and.
4MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London W2 1PG, United Kingdom.

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.

Sustained high incidence of injuries from burns in a densely populated urban slum in Kenya: An emerging public health priority. Burns. 2014 Sep;40(6):1194-200.

Authors: Wong JM1, Nyachieo DO1, Benzekri NA1, Cosmas L1, Ondari D1, Yekta S2, Montgomery JM1, Williamson JM1, Breiman RF3.
1Global Disease Detection Division, Center for Global Health, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya and the Kenya Medical Research Institute (KEMRI)-CDC Research Collaboration.
2Division of Plastic and Reconstructive Surgery, University of Toronto, Toronto, ON, Canada.
3Global Disease Detection Division, Center for Global Health, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya and the Kenya Medical Research Institute (KEMRI)-CDC Research Collaboration. Electronic address: rfbreiman@emory.edu.

INTRODUCTION: Ninety-five percent of burn deaths occur in low- and middle-income countries (LMICs); however, longitudinal household-level studies have not been done in urban slum settings, where overcrowding and unsafe cook stoves may increase likelihood of injury.

METHODS: Using a prospective, population-based disease surveillance system in the urban slum of Kibera in Kenya, we examined the incidence of household-level burns of all severities from 2006-2011.

RESULTS: Of approximately 28,500 enrolled individuals (6000 households), we identified 3072 burns. The overall incidence was 27.9/1000 person-years-of-observation. Children <5 years old sustained burns at 3.8-fold greater rate compared to (p<0.001) those ≥5 years old. Females ≥5 years old sustained burns at a rate that was 1.35-fold (p<0.001) greater than males within the same age distribution. Hospitalizations were uncommon (0.65% of all burns).

CONCLUSIONS: The incidence of burns, 10-fold greater than in most published reports from Africa and Asia, suggests that such injuries may contribute more significantly than previously thought to morbidity in LMICs, and may be increased by urbanization. As migration from rural areas into urban slums rapidly increases in many African countries, characterizing and addressing the rising burden of burns is likely to become a public health priority.

Factors Influencing Household Uptake of Improved Solid Fuel Stoves in Low- and Middle-Income Countries: A Qualitative Systematic Review. Int. J. Environ. Res. Public Health, Aug 2014.

Authors: Stanistreet Debbi 1,*, Puzzolo Elisa 1, Bruce Nigel 1, Pope Dan 1 and Rehfuess Eva 2
1 Department of Public Health and Policy, Institute of Psychology, Health and Society, Whelan Building, University of Liverpool, Liverpool L69 3GB, UK; E-Mails: puzzoloe@liv.ac.uk (P.E.); ngb@liv.ac.uk (B.N.); danpope@liv.ac.uk (P.D.)
2 Institute for Medical Informatics, Biometry and Epidemiology, University of Munich, Marchioninistr. 15, Munich 81377, Germany; E-Mail: rehfuess@ibe.med.uni-muenchen.de
* Author to whom correspondence should be addressed; E-Mail: debbi@liv.ac.uk; Tel.: +44-151-794-5583.

Abstract: Household burning of solid fuels in traditional stoves is detrimental to health, the environment and development. A range of improved solid fuel stoves (IS) are available but little is known about successful approaches to dissemination. This qualitative systematic review aimed to identify factors that influence household uptake of IS in low- and middle-income countries. Extensive searches were carried out and studies were screened and extracted using established systematic review methods. Fourteen qualitative studies from Asia, Africa and Latin-America met the inclusion criteria. Thematic synthesis was used to synthesise data and findings are presented under seven framework domains.

Findings relate to user and stakeholder perceptions and highlight the importance of cost, good stove design, fuel and time savings, health benefits, being able to cook traditional dishes and cleanliness in relation to uptake. Creating demand, appropriate approaches to business, and community involvement, are also discussed. Achieving and sustaining uptake is complex and requires consideration of a broad range of factors, which operate at household, community, regional and national levels. Initiatives aimed at IS scale up should include quantitative evaluations of effectiveness, supplemented with qualitative studies to assess factors affecting uptake, with an equity focus.

Liverpool School of Tropical Medicine - CAPS Study: An advanced cookstove intervention to prevent pneumonia in children under 5 years old in Malawi: a cluster randomised controlled trial.


  • Malawi has one of the highest rates of death among infants and the under fives (69 and 110 per 1000 live births respectively in 2009) despite having made progress towards meeting the Millennium Development Goal of reducing child mortality.
  • Pneumonia is the leading cause of death and one of the commonest causes of morbidity: around 300 per 1000 children under the age of 5 are diagnosed with pneumonia every year.
  • Exposure to smoke produced when biomass fuels (animal or plant material) are burned in open fires is a major avoidable risk factor for pneumonia.
  • In Malawi, where at least 95% of households depend on biomass as their main source of fuel, biomass smoke exposure is likely to be responsible for a substantial burden of this disease.
  • Smoke from burning biomass in open fires also causes other health problems including chronic lung disease, lung cancer, heart disease, stillbirth and low birth weight; it is also thought to be an important driver of global climate change.
  • The problem of biomass smoke exposure is seen across Africa where around 700 million people burn biomass fuels to provide energy for cooking, heating and lighting.
  • The problem extends right around the globe where around half the worlds population are dependent on biomass fuels for their day-to-day energy requirements.
  • Around 4 million people die every year around the world from the effects of biomass smoke.

[click to continue…]

Bookmark and Share

EPA/Winrock Webinar – Results from CCT Studies and Stove Design and Performance Testing Workshops in Vietnam, Mexico, and Nepal, July 29, 2014.

In 2012 and 2013 Aprovecho Research Center, with support from the U.S. EPA and Winrock International, conducted Controlled Cooking Test (CCT) field studies and provided technical training for organizations working to promote cleaner, more efficient cooking technologies in Vietnam (2012), Mexico (2013), and Nepal (2013). On July 2, 2014 Winrock and the U.S. EPA hosted a webinar to present results and lessons learned from the studies and information about how these results can inform and improve cookstove design, performance and use. The webinar also provided context and outcomes from the regional technical capacity building workshops that complemented each field study. Mike Hatfield presented on behalf of Aprovecho Research Center.

Perspectives in Household Air Pollution Research: Who Will Benefit from Interventions? Curr Envir Health Rpt, July 2014.

Authors: Maggie L. Clark & Jennifer L. Peel

Despite increasing recognition surrounding this global environmental health problem, much remains to be elucidated regarding exposure response relationships, particularly among potentially susceptible population subgroups. Given that many of the communities most affected by household air pollution exposures also experience elevated exposures to poverty, psychosocial stressors, other environmental pollutants, and comorbid conditions, research needs to correctly specify risks due to these potentially interacting risk factors. Although suggestive evidence exists for differential improvements in health following reductions in ambient air pollution concentrations among specific subgroups, the question remains as to who will benefit and to what extent from efforts to reduce exposures to emissions from household solid fuel combustion. The ability to know what to expect from cookstove interventions and to accurately describe the presence of distinct subgroup responses is crucial to reduce uncertainty and to encourage policy makers to enact change.

Study delves into Nepal’s household hazardsNic White, Medical Press, Aug 8, 2014

A pilot study of Nepalese kitchens aims to improve public health and reduce burn injuries in the poorest neighbourhoods of South Asia, a UWA burn researcher says.

Burn Injury Research Unit Assistant Professor Hilary Wallace says 75 per cent of burns in South Asia occur in the home, mostly in the kitchen, and targeted education and financial support interventions could help save many lives.

“What happens in the kitchen can improve or undermine public health,” she says.

“In many of these poverty-stricken areas, burns are more common than AIDS or tuberculosis.”

[click to continue…]

Bookmark and Share

Adherence to reduced-polluting biomass fuel stoves improves respiratory and sleep symptoms in children. BMC Pediatrics 2014, 14:12.

Roberto A Accinelli, et al. Corresponding authors: Roberto A Accinelli roberto.accinelli@upch.pe

Background – Symptoms of sleep apnea are markedly increased in children exposed to smoke from biomass fuels and are reduced by kitchen stoves that improve indoor biomass pollution. However, the impact of adherence to the use of improved stoves has not been critically examined.

Methods – Sleep-related symptom questionnaires were obtained from children <15 years of age in 56 families residing in the communities of Lliupapuquio, Andahuaylas province in Peru before and 2 years after installation of less-polluting Inkawasi cooking stoves.

Results – 82 children with lifetime exposures to indoor fuel pollution were included. When compared to those alternating between both types of stoves or those using traditional stoves only, those children who exclusively used Inkawasi cooking stoves showed significant improvements in sleep and respiratory related symptoms, but some minor albeit significant improvements occurred when both stoves were concomitantly used.

Conclusions- Improvements in respiratory and sleep-related symptoms associated with elevated indoor biomass pollution occur only following implementation and exclusive utilization of improved kitchen stoves.

Tracking Access to Nonsolid Fuel for Cooking, 2014.

Ghosh Banerjee, Sudeshna; Portale, Elisa; Adair-Rohani, Heather; Bonjour, Sophie. World Bank.

The World Health Organization estimates that in 2012 about 4.3 million deaths occurred because of exposure to household air pollution caused by smoke from the incomplete combustion of fuels such as wood, coal, and kerosene. Inefficient energy use in the home also poses substantial risks to safety, causing burns and injuries across the developing world. To support the achievement of these goals, a starting point must be set, indicators developed, and a framework established to track those indicators until 2030.

The World Bank and International Energy Agency have led a consortium of 15 international agencies to produce data on access to nonsolid fuel for the SE4ALL Global Tracking Framework. Launched in 2013, the framework defines access to modern cooking solutions is as the use of nonsolid fuels for the primary method of cooking. Nonsolid fuels include (i) liquid fuels (for example, kerosene, ethanol, or other biofuels), (ii) gaseous fuels (such as natural gas, LPG, and biogas), and (iii) electricity. These are in contrast to solid fuels such as (i) traditional biomass (wood, charcoal, agricultural residues, and dung), (ii) processed biomass (pellets, briquettes); and (iii) other solid fuels (such as coal and lignite).