Chronic Obstructive Pulmonary Disease (COPD) Stove Project
The Chronic Obstructive Pulmonary Disease (COPD) Stove Project in Quetzaltenango, Guatemala, is a collaboration between UC Berkeley, UCSF, and the Universidad del Valle de Guatemala. This will be a prospective cohort study of 200 individuals with COPD due to biomass smoke exposure identified with spirometry at a public hospital.  Eligible women will be complete a baseline health and exposure questionnaire, after which they will be followed prospectively with spirometry and symptom questionnaires for 6 months. Additionally, 32 participants of the main study who cook primarily over an open fire will be recruited for a stove intervention sub-study. These participants will receive one of four types of improved cookstoves locally available in Guatemala (Dona Dora, Helps-Onil Stove, liquid propane gas [LPG] stove and LPG stove with a partial gas subsidy).  Stove performance and acceptability will be assessed with personal and kitchen monitoring of PM and CO, stove use monitors (SUMs), and a stove acceptability questionnaire before and after the intervention. This group will be followed for 6 months post-intervention with periodic spirometry, symptom questionnaires, and blood samples to assess for serum markers of inflammation commonly associated with biomass smoke exposure. Overall, we believe that those with COPD may be a group that is particularly sensitive to on-going biomass smoke exposure, and a relevant target for stove interventions.

Guarnieri MJ, Diaz JV, Basu C, Diaz A, Pope D, et al. (2014) Effects of Woodsmoke Exposure on Airway Inflammation in Rural Guatemalan Women. PLoS ONE 9(3): e88455. doi:10.1371/journal.pone.0088455

NACER-Neurodevelopment and anthropometric growth of infants exposed to household air pollution in rural Guatemala:  A pilot study for a future clean stove intervention trial
NACER was an 18-month longitudinal pilot study (NACER) conducted between January 2012 and December 2013 in rural Guatemala in collaboration with UCSF and Universidad del Valle de Guatemala. The aim of the study was to examine the impact of maternal and infant exposures to household air pollution on infant outcomes, including low birth weight, preterm birth and infant neurodevelopment. Personal CO and PM exposures were measured using real time monitors worn on vests by the pregnant women/mothers, or kept near the infant after birth.  Airborne polycyclic aromatic hydrocarbons (8 vapor-phase PAHs measured using passive diffusion badges) were measured at 24-28 weeks of pregnancy and during the post-partum meeting. We measured urinary metabolites of PAHs/VOCs/8-OHdG and 8-isoprostane on women 3 months after the delivery of the infant. A 12 week randomized stove (“Doña Dora” chimney stove/behavior change intervention was conducted from January to April 2014. 

Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE)
We carried out a study in the Western Highlands of Guatemala to better understand the relationship between acute respiratory infections in children and exposure to indoor air pollution. To do this, we chose several communities that are well suited for such a study and have installed an improved cookstove called a plancha in half of the participating households. We examined acute respiratory infections (ARI) in children 18 months of age over a 2 year period to see if there was a difference in the incidence of ARI in children who have the plancha compared to children who do not have the plancha. We measured levels of pollution in households that have the plancha and those without the plancha. After completing the study, all participating households received a plancha.

For more information, click here.

Chronic Respiratory Effects of Early Childhood Exposure to Respirable Particulate Matter (CRECER)
Our primary goal is to follow the cohort of children who participated in the Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) – Guatemala, longitudinally for a 5-year period to elicit the chronic effects of inhaled PM during the critical time window of infant lung development on respiratory health.

This recently concluded intervention trial randomized 500 rural Guatemalan households to improved plancha stoves (intervention) or traditional open wood stoves (control) and measured as the main study outcome, the incidence of acute lower respiratory infections (ALRI) in children from birth to 18 months. In addition, extensive exposure assessment was performed and preliminary data suggests that the plancha stove has significantly decreased the levels of biomass smoke exposure inside the intervention homes. At the end of the trial, which concluded in December 2004, all control households were offered an improved plancha stove.

This randomized trial has created a unique opportunity to follow this cohort of children who had variable exposures to biomass smoke from birth to 18 months (critical time window for lung development) and observe the effects of these exposures on future respiratory health.

For more information, click here.



Heart of the Hearth 
One way of developing clean biomass stoves is to think of the combustion chamber separately from the stove itself.  If a clean robust “heart of the hearth (HOH)” can be developed and mass manufactured, it could potentially be brought to villages where it would be inserted into a stove body customized for local needs.  To try this out, we are contributing to a project to develop a HOH for massive chimney stoves, which have been quite popular in many parts of the world, but have not to date been very clean although good ones save fuel.  It is thus an attempt to try to make the “popular clean” in distinction to trying to make the “clean popular,” i.e. promote new stove designs that have not been proved popular.  Our research group is conducting independent monitoring and evaluation of the first attempt to try such an approach, which is using the popular Patsari stove in Mexico utilizing a HOH chamber modified from the BioLite forced draft two-stage combustion chamber.   This project is supported by the US Department of Energy.

Sagar A and Smith KR (2013). An innovation prize for clean cookstoves. Nature, 497: 317.

Use, Displacement, and Field Performance of Advanced Combustion Stoves
Sizable benefits from the implementation of cookstove programs can only occur when the cleaner and more efficient stoves perform well in the field, are used frequently, and displace the older, less efficient stoves. We used Stove Use Monitors (SUMs) to estimate the levels of usage of advanced stoves and the displacement of traditional fires, in two stove interventions programs in Mexico and India. The specific objectives of this study were to: 

  1. Define metrics of stove use and adoption to link field measurements of fuel consumption and emissions to controlled laboratory performance tests.
  2. Test in-field performance of two advanced-combustion stove combinations: the Patsari-LPG-traditional hearths in Mexico and Phillips-LPG-traditional hearths in India and test the proposed linking metrics using SUMs.
  3. Estimate the health and climate related impacts from the dominant patterns (or clusters) of stove use and fuel-device stacking in Michoacan-Mexico and Haryana-India.

We instrumented with SUMs all the stoves present in the study homes to identify the main stacking clusters and to quantify the levels of combined stove usage. In a subsample of homes at each site we measured in-field emissions simultaneously with the SUMs. 


Householdair pollution from biomass fuels in urban and rural areas in Paraguay
In collaboration with the Direccion General de Salud Ambiental (DIGESA), Ministry of Health, and PAHO-Paraguay, we conducted the first study characterizing the air quality of households using firewood or charcoal to cook as well as those withusing LPG or electricity.  We monitored 24-hour PM2.5 and CO levels in the household kitchen area. Additionally, an outdoor PM2.5 sampling campaign was performed in each comunity. Indoor PM2.5 levels were high in households using firewood, followed by those using charcoal. Households cooking with LPG and electricity showed PM2.5 concentrations similar to levels found at outdoor. Ambient PM2.5 were frequently above 35 ug/m3 and was attributable to biomass used to cook, but also to combustion of residential and agricultural waste.

The project findings will contribute to advancing the DIGESA and PAHO-Paraguay strategic plans for air pollution. These include the development of national air quality guidelines, justification for programs supporting clean energy in households, and increasing national capacity for air quality monitoring. It is hoped this research will be useful to improve the life quality of families with economic needs in Paraguay. 


To accomplish the overall goal of providing evidence necessary to evaluate the impact of reducing exposure to biomass smoke on lung function decline, we are building on the infrastructure of the Cooking Stove and Pneumonia Study (CAPS) randomized controlled trial (RCT) of the Philips gasifier stove for the prevention of childhood pneumonia and a cross-sectional Burden of Lung Disease (BOLD) study of adult respiratory health in rural Malawi. In CAPS, approximately 3,600 households have been recruited from 50 villages in the Chikhwawa district using a cluster randomization approach at the village level. The CAPS protocol has been reviewed and published by the Lancet. For the BOLD study, 2,000 men and women in two age strata (18-39 and ≥40) are currently being recruited from the villages participating in CAPS. We plan to follow the BOLD participants annually for 6 years to assess personal exposure (PM2.5, CO, and BC), lung function, and respiratory symptoms. In addition, because ~50% of the 2,000 participants to be recruited for the BOLD study will be from CAPS households, we will be able to conduct an RCT of the efficacy of the Philips stove in this nested sub-cohort.




Kaski Air Pollution Study (KAPS)
The Kaski Air Pollution Study (KAPS) is an NIEHS-funded R01 case-control study of pulmonary TB disease and latent TB infection  in Nepal (Co-PIs: Michael Bates and Kirk Smith).  The cases are adult men and women recruited from the Regional TB Clinic (RTC) in Pokhara, and the controls are from surrounding communities, recruited through population-based sampling.  The aims are to determine whether biomass fuel and/or kerosene used for cooking, heating or lighting are risk factors for M tuberculosis infection or TB disease.

Bhaktapur Air Pollution Case-Control Study
The Bhaktapur air pollution case-control study was funded by the governments of Norway and Denmark in 2006 and the Kirk Smith research group was invited to add a household air pollution (HAP) monitoring component.  This study examines the association between solid fuel HAP and risk of acute lower respiratory infection (ALRI) in young children in Bhaktapur, Nepal. The HAP level was measured in 824 kitchens of pneumonia cases and age-matched controls without pneumonia using the UC Berkeley Particle and Temperature Sensors (UCB-PATS). Separately, a sub-study was conducted in 60 households to validate the monitoring instruments.

PEER Study of Child Pneumonia
Through the PEER Health program (click 'Read More' below for more information), our research group is assisting colleagues in Nepal to conduct a study examining the impacts on household air pollution and child respiratory disease of a biogas intervention in Western Nepal.  Biogas, methane produced biologically from animal waste in household digesters and burned cleanly for cooking and lighting, is used in many parts of the world, but has apparently not yet been examined systematically as a health intervention. 


Newborn Stove Project (NBSP)
NSBP – a partnership between the International Clinical Epidemiology Network (INCLEN), Columbia University, UC Berkeley, and Sri Ramachandra University (SRU) – evaluated the feasibility of distributing clean cookstoves through the rural antenatal care system, which targets arguably the most vulnerable population -- poor, pregnant, rural women. The study distributed 200 blower stoves to pregnant women at INCLEN's SOMAARTH field site and tracked usage of the stoves continuously for 15 months using our Stove Use Monitoring System (SUMS) and measured pollutant concentrations and exposures before and after introduction of the stove. Funding for this project came from the United States Centers for Disease Control and Prevention, the World Lung Foundation, and the World Bank. For more information, see 

Mukhopadhyay R, Sambandam S, Pillarisetti A, Jack D, Mukhopadhyay K, Balakrishnan K, Vaswani M, Bates MN, Kinney PL, Arora N, & Smith, KR. (2012). Cooking practices, air quality, and the acceptability of advanced cookstoves in Haryana, India: an exploratory study to inform large-scale interventions. Global Health Action, 5. doi:10.3402/gha.v5i0.19016

Village and Regional Pollution from Household Fuels
This multi-year project has three goals and is conducted with several US and Indian partners at the Haryana SOMAARTH site noted above and operated by INCLEN.

  1. The contribution of household fuels to outdoor air pollution has been estimated to be substantial in many parts of the world, for example about one-quarter of ambient PM2.5 in India, but has not been well characterized.  This is partly due to lack of understanding of how much such sources contribute to secondary particle formation in the atmosphere, a significant portion of outdoor pollution exposure.  Although outdoor pollution is widely recognized as a problem and most major governments, including India’s, have clean air legislation, there is little understanding of the degree to which clean household combustion will be needed to meet outdoor air pollution goals.  Quantifying these relationships through over all seasons is one purpose of this project.
  2. In addition, there is recognition that changing out one household at a time in a village may not be result in much reduction in exposure because of the “neighborhood pollution” created when the rest of the community is still using polluting cooking methods. This project addresses whether community-scale interventions may be needed to reduce personal exposures to cookstove emissions in India
  3. As advanced biomass stoves have not to date been able to reliably achieve low emissions, this project focuses on monitoring the changes in emissions and exposures due to community-level introduction of fully clean alternatives: LPG and electric cooking.

 Partial funding has come from the United States Environmental Protection Agency.

Heat stress among farmers
One of the potentially large impacts of climate change could be an increasingly difficult trade off in outdoor workers between productivity and health as the combined increase in temperature and humidity approaches or exceeds physiological limits for manual labor.  Jointly with Indian colleagues in Chennai, we are conducing preliminary measurements and interviews during the summer 2014 with small farmers in Tamil Nadu to examine how they deal with this trade-off.


Savannakhet region 
Protocol for estimating health benefits from a stove intervention: Jointly with colleagues  at Berkeley Air Monitoring Group, the World Bank, and LIRE (Vientiane), we are developing standard methods for estimating the health benefits (in the form of ADALYs – avoided disability adjusted life years) accruing to a stove project to introduce advanced combustion stoves in villages within the Savannakhet region of Laos.  This involves air pollution field work before and after the introduction of the stoves, modeling changes in personal exposure to PM2.5, and using the Household Air Pollution Invervention Tool (HAPIT) to calculate the estimated change in adult and child disease rates that would result.


Policy Project with the Mongolian Ministry of Environment & Green Development
With many partners, we are estimating the health impacts of several energy policy pathways for the Mongolian capital city of Ulaanbaatar (UB) through 2025. Pathways include considerations for household heating, electricity generation, and traffic, and are used to model outdoor and indoor environmental exposures to particulate matter less than 2.5 microns (PM2.5). Exposure and health impacts are estimated. 

A Pilot Study of Longterm, Wintertime Indoor PM2.5 Concentrations in Gers in Ulaanbaatar, Mongolia
Continuous measurements of particulate matter smaller than 2.5 microns (PM2.5) were taken inside and directly outside households in UB during winter 2014. We seek to better understand the  magnitudes and patterns of variation in PM2.5 levels in the ger region of UB.


Village ambient pollution
In collaboration with Chinese colleagues, we monitored the metrology, outdoor air pollution, and household stove use over a year in a village outside Beijing.  We found outdoor pollution levels as severe as in the middle of the city, which were influenced heavily by local household sources, mainly coal and wood heating in the winter.  Publications in progress.

An Assessment of Programs to Promote Improved Household Stoves in China

This project was an independent, multidisciplinary review of China’s improved rural household stoves programs that were carried out by MOA, MOH, and SDPC. The project had three major objectives, i.e.:

1. to evaluate the implementation methods used to promote improved stoves;
2. to evaluate the commercial stove production and marketing organizations that were created during the same period; and
3. to measure the household impacts of the programs.