Changes in Wood Smoke Exposures and Respiratory Health Before and After Installation of a Chimney Cookstove in Rural Guatemala

AMANDA L. NORTHCROSS (1), Jennifer Mann (1), John Balmes (1), Alisa Jenny (1). Zohir Chowdury (3), Eduardo Canuz (4), Kirk R. Smith (1)

(1) University of California Berkeley (2) University of California San Francisco (3) San Diego State University (4) Universidad de Valle de Guatemala

     Abstract Number: 2512
     Last modified: February 8, 2010

Abstract
For many households around the world the simple act of cooking creates exposure to hundreds of toxic compounds in the form of incomplete combustion products. The smoke produced from burning household biomass fuels such as wood, and crop residues is estimated by WHO to be responsible for 1.6 million premature deaths annually. Reducing the exposure to smoke by the use of a chimney cookstove removes the smoke from the kitchen. To quantify these benefits to both toddlers and babies we have conducted two studies.

The RESPIRE trial conducted in the rural highlands of Guatemala enrolled 534 households into a randomized improved cook-stove intervention study. The focus of the study was the impact of indoor air pollution (IAP) on acute lower respiratory infection incidence among children. The households were divided into a control group, which continued to cook on open fires and an intervention group, receiving an improved cook-stove. RESPIRE was an efficacy study in which use, repair, and maintenance of the stoves was promoted during weekly visits.

The CRECER study monitored the same cohort of RESPIRE children longitudinally for an additional 5 years to elicit the chronic effects of PM inhaled during the time of infant lung development on respiratory health. 166 new homes were enrolled into the CRECER study to compensate for the families in RESPIRE who chose not to continue. 557 homes participated in the CRECER study. Here we report CO and PM2.5 concentrations before and after installation of the chimney stove in these new CRECER households to evaluate the ability of the improved stove to reduce indoor air pollutant exposures in an effectiveness mode, i.e. without weekly visits to promote use and maintenance.

PM2.5 was measured both continuously and cumulatively in a subset of homes using the UC Berkeley particle and temperature monitor. In addition gravimetric filters coupled with cyclones were also used to determine 48-hour mean concentrations. CO was measured continuously in the kitchens, and on mothers. Personal CO was measured on all study children using passive diffusion CO tubes, and on mothers in the subset of homes. The improved stove reduced kitchen concentrations by 66% and 62% respectively for CO and PM2.5. The reduction in personal exposures to CO by the study children was only 22%. In comparison, the newly recruited infants had much higher personal exposures than their older siblings emphasizing the age dependant nature of kitchen smoke exposures.

The goal of CRECER is to measure the chronic effects of inhaled PM and CO during the critical time window of infant lung development on respiratory health. The relationship of both respiratory health indicators and allergy skin testing with CO exposures will be evaluated.