Are rocket mud stoves associated with lower indoor carbon monoxide and personal exposure in rural Kenya?

UNLABELLED Household use of biomass fuels is a major source of indoor air pollution and poor health in developing countries. We conducted a cross-sectional investigation in rural Kenya to assess household air pollution in homes with traditional three-stone stove and rocket mud stove (RMS), a low-cost unvented wood stove. We conducted continuous measurements of kitchen carbon monoxide (CO) concentrations and personal exposures in 102 households. Median 48-h kitchen and personal CO concentrations were 7.3 and 6.5 ppm, respectively, for three-stone stoves, while the corresponding concentrations for RMS were 5.8 and 4.4 ppm. After adjusting for kitchen location, ventilation, socio-economic status, and fuel moisture content, the use of RMS was associated with 33% lower levels of kitchen CO [95% Confidence Interval (CI), 64.4-25.1%] and 42% lower levels of personal CO (95% CI, 66.0-1.1%) as compared to three-stone stoves. Differences in CO concentrations by stove type were more pronounced when averaged over the cooking periods, although they were attenuated after adjusting for confounding. In conclusion, RMS appear to lower kitchen and personal CO concentrations compared to the traditional three-stone stoves but overall, the CO concentrations remain high. PRACTICAL IMPLICATIONS The rocket mud stoves (RMS) were associated with lower CO concentrations compared to three-stone stoves. However, the difference in concentrations was modest and concentrations in both stove groups exceeded the WHO guideline of 7 μg/m(3) , suggesting the unvented RMSs on their own are unlikely to appreciably benefit health in this population. Greater air quality benefit could be realized if the stoves were complemented with behavior change, including education on extinguishing fire when not in use as well as fuel drying, and cooking in locations that are separate from the main house.

[1]  Pratim Biswas,et al.  Evaluation of mass and surface area concentration of particle emissions and development of emissions indices for cookstoves in rural India. , 2011, Environmental science & technology.

[2]  L Punnett,et al.  Incorporating work organisation into occupational health research: an invitation for dialogue , 2007, Occupational and Environmental Medicine.

[3]  P. Layde,et al.  Health effects of an efficient vented stove in the highlands of Guatemala , 2011, Global public health.

[4]  Justus K. Laichena,et al.  The effects of woodfuel consumption in the ASAL areas of kenya: the case of marsabit forest , 2000 .

[5]  Majid Ezzati,et al.  Addressing the Impact of Household Energy and Indoor Air Pollution on the Health of the Poor: Implic , 2002 .

[6]  Sumi Mehta,et al.  Assessing Household Solid Fuel Use: Multiple Implications for the Millennium Development Goals , 2006, Environmental health perspectives.

[7]  Amanda Northcross,et al.  Estimating personal PM2.5 exposures using CO measurements in Guatemalan households cooking with wood fuel. , 2010, Journal of environmental monitoring : JEM.

[8]  R. Hornung,et al.  Estimation of Average Concentration in the Presence of Nondetectable Values , 1990 .

[9]  K. R. Smith,et al.  Indoor air pollution in developing countries: recommendations for research. , 2002, Indoor air.

[10]  M. Kees,et al.  The role of donor organisations in promoting energy efficient cook stoves , 2011 .

[11]  M. Ezzati,et al.  Patterns and predictors of personal exposure to indoor air pollution from biomass combustion among women and children in rural China. , 2011, Indoor air.

[12]  Daniel M Kammen,et al.  Greenhouse gas implications of household energy technology in Kenya. , 2003, Environmental science & technology.

[13]  C. Molyneux,et al.  Estimating inequalities in ownership of insecticide treated nets: does the choice of socio-economic status measure matter? , 2009, Health policy and planning.

[14]  B. Armstrong,et al.  Public health benefits of strategies to reduce greenhouse-gas emissions: household energy , 2009, The Lancet.

[15]  R. Maynard,et al.  Effects on health of prolonged exposure to low concentrations of carbon monoxide , 2002, Occupational and environmental medicine.

[16]  B G Armstrong,et al.  Effect of measurement error on epidemiological studies of environmental and occupational exposures. , 1998, Occupational and environmental medicine.

[17]  M. Jaakkola,et al.  Biomass fuels and health: the gap between global relevance and research activity. , 2006, American journal of respiratory and critical care medicine.

[18]  E. Wafula,et al.  Effect of improved stoves on prevalence of acute respiration infection and conjunctivitis among children and women in a rural community in Kenya. , 2009, East African medical journal.

[19]  L. Ng'ang'a,et al.  Home environment and asthma in Kenyan schoolchildren: a case-control study. , 1995, Thorax.

[20]  L. Naeher,et al.  Evaluation of exposure reduction to indoor air pollution in stove intervention projects in Peru by urinary biomonitoring of polycyclic aromatic hydrocarbon metabolites. , 2011, Environment international.

[21]  Ben Armstrong,et al.  CONFIDENCE INTERVALS FOR ARITHMETIC MEANS OF LOGNORMALLY DISTRIBUTED EXPOSURES , 1992 .

[22]  Dorisel Torres,et al.  Climate change impact of biochar cook stoves in western Kenyan farm households: system dynamics model analysis. , 2011, Environmental science & technology.

[23]  Ken R. Smith Indoor Air Pollution , 1999 .

[24]  Daniel M Kammen,et al.  The health impacts of exposure to indoor air pollution from solid fuels in developing countries: knowledge, gaps, and data needs. , 2002, Environmental health perspectives.

[25]  C. Viau,et al.  Indoor exposure to polycyclic aromatic hydrocarbons and carbon monoxide in traditional houses in Burundi , 2000, International archives of occupational and environmental health.

[26]  Daniel Pope,et al.  Impact of Reduced Maternal Exposures to Wood Smoke from an Introduced Chimney Stove on Newborn Birth Weight in Rural Guatemala , 2011, Environmental health perspectives.

[27]  J. Manuel The quest for fire: hazards of a daily struggle. , 2003, Environmental health perspectives.

[28]  Kirk R. Smith,et al.  Indoor air pollution and acute respiratory infections. , 2003, Indian pediatrics.

[29]  Nigel Bruce,et al.  Effect of reducing indoor air pollution on women's respiratory symptoms and lung function: the RESPIRE Randomized Trial, Guatemala. , 2009, American journal of epidemiology.

[30]  J T Spickett,et al.  Indoor air pollution from biomass combustion and respiratory symptoms of women and children in a Zimbabwean village. , 2007, Indoor air.

[31]  Nigel Bruce,et al.  Personal child and mother carbon monoxide exposures and kitchen levels: Methods and results from a randomized trial of woodfired chimney cookstoves in Guatemala (RESPIRE) , 2010, Journal of Exposure Science and Environmental Epidemiology.

[32]  F. White,et al.  Health and social impacts of improved stoves on rural women: a pilot intervention in Sindh, Pakistan. , 2005, Indoor air.

[33]  J. Ayres,et al.  Biomass fuel use and indoor air pollution in homes in Malawi , 2009, Occupational and Environmental Medicine.

[34]  Daniel M. Kammen,et al.  Comparison of Emissions and Residential Exposure from Traditional and Improved Cookstoves in Kenya , 2000 .

[35]  E. Wafula,et al.  Characteristics related to the incidence and prevalence of acute respiratory tract infection in young children in Kenya. , 1994, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[36]  H. Riojas-Rodríguez,et al.  Household Firewood Use and the Health of Children and Women of Indian Communities in Chiapas, Mexico , 2001, International journal of occupational and environmental health.

[37]  W. Tefera,et al.  Inhalation Exposures to Particulate Matter and Carbon Monoxide during Ethiopian Coffee Ceremonies in Addis Ababa: A Pilot Study , 2010, Journal of environmental and public health.

[38]  O. Masera,et al.  Impact of the Improved Patsari Biomass Stove on Urinary Polycyclic Aromatic Hydrocarbon Biomarkers and Carbon Monoxide Exposures in Rural Mexican Women , 2011, Environmental health perspectives.

[39]  Omar Masera,et al.  Reduction in personal exposures to particulate matter and carbon monoxide as a result of the installation of a Patsari improved cook stove in Michoacan Mexico. , 2008, Indoor air.

[40]  Wilhemina Quaye,et al.  Indoor air quality impacts of an improved wood stove in Ghana and an ethanol stove in Ethiopia , 2009 .

[41]  M. Brauer,et al.  Woodsmoke Health Effects: A Review , 2007, Inhalation toxicology.

[42]  Daniel M Kammen,et al.  Indoor air pollution from biomass combustion and acute respiratory infections in Kenya: an exposure-response study , 2001, The Lancet.

[43]  Stephen J Reynolds,et al.  Indoor air pollution, cookstove quality, and housing characteristics in two Honduran communities. , 2010, Environmental research.

[44]  Nigel Bruce,et al.  Indoor air pollution from biomass fuel smoke is a major health concern in the developing world , 2008, Transactions of the Royal Society of Tropical Medicine and Hygiene.

[45]  K. R. Smith,et al.  Particulate matter and carbon monoxide in highland Guatemala: indoor and outdoor levels from traditional and improved wood stoves and gas stoves. , 2000, Indoor air.

[46]  N. Bruce,et al.  Indoor air pollution in developing countries: a major environmental and public health challenge. , 2000, Bulletin of the World Health Organization.

[47]  Alan Hubbard,et al.  Effect of reduction in household air pollution on childhood pneumonia in Guatemala (RESPIRE): a randomised controlled trial , 2011, The Lancet.

[48]  Nigel Bruce,et al.  Combining Individual- and Group-Level Exposure Information: Child Carbon Monoxide in the Guatemala Woodstove Randomized Control Trial , 2009, Epidemiology.

[49]  Nigel Bruce,et al.  Impact of improved stoves, house construction and child location on levels of indoor air pollution exposure in young Guatemalan children , 2004, Journal of Exposure Analysis and Environmental Epidemiology.

[50]  Evans Kituyi,et al.  Carbon monoxide and nitric oxide from biofuel fires in Kenya , 2001 .

[51]  Majid Ezzati,et al.  Biomass fuels and respiratory diseases: a review of the evidence. , 2008, Proceedings of the American Thoracic Society.

[52]  M. Montgomery,et al.  Measuring living standards with proxy variables , 2011, Demography.

[53]  N. Bruce,et al.  Risk of low birth weight and stillbirth associated with indoor air pollution from solid fuel use in developing countries. , 2010, Epidemiologic reviews.