Reducing indoor air pollution with a randomised intervention design - A presentation of the Stove Intervention Study in the Guatemalan Highlands

Indoor air pollution from the burning of solid fuels (like wood and coal) in simple stoves is a global problem especially affecting people living in poor rural areas of the world. When typically burnt on open fires, the resulting indoor pollution levels may be orders of magnitude higher than levels recommended by inter- national guidelines. The most important health effects seem to be acute lower respiratory infections (ALRI) in children and chronic obstructive pulmonary disease in women. So far, health risks from solid fuel use have only been studied with observational designs, often with poor assessment of exposures. Hence there is good reason to conduct a well-designed randomised intervention study. In this randomised study, conducted in a poor rural community in Guatemala, indoor exposure burden in the intervention group is reduced by replacing open fires with new chimney stoves burning the same wood fuels. Participating households (n=534) all started the project with a child less than four months or a preg- nant woman, and are being followed until the child reaches 18 months. At the end of follow-up, the control households receive their new stove. The main health outcome investigated is the incidence of ALRI in infants. Also, respiratory and cardiovascular health in women is studied. Preparations are also being made to study asthma/atopy in the children as they grow older. This study will define the relationship between expo- sure and disease more completely, quantify the impacts of reducing indoor air pollution and document the potential for prevention of ill-health that new stoves give. It is the first randomised controlled trial ever per- formed on health effects from combustion pollutants in normal populations.