Impacts of Poor Indoor Air Quality
With economic development, there is generally a transition up the so-called 'energy-ladder' from polluting fuels to those that burn cleaner and hotter. However, Over two billion people lack access to modern energy carriers and services and almost half of the world's population relies predominantly on fuels at the lower end of this energy-ladder, and, for many,
the prospects of moving up the ladder in the short term appear limited.
In these poor rural and urban homes, biomass fuels( wood, charcoal,animal dung, and crop wastes) and coal are typically burnt in open fires or poorly functioning stoves, often indoors, with inadequate ventilation for the smoke. This leads to very high levels of pollution in the homes where especially women and young children are exposed on a daily basis. Smoke from these fuels contains many health damaging pollutants, including
- carbon monoxide,
- nitrogen oxides,
- benzene, and many others
Together, these pollutants are known to be capable of irritating the airways and lungs, reducing the resistance to infection, and increasing the risk of cancer.
The World Health Report-2002 ranked indoorairpollution from solid fuels as the fourth most important health risk factor in least developed countries, where 40% of the world's population lives. And the majority of these are women, who are normally responsible for food
preparation and cooking, and infants/young children who spend time near the cooking area. Indoor air pollution is the clearest and most direct physical health risk because biomass smoke exposure increases the risk of a range of common and serious diseases Chief among these which are quite well established particularly among women and children are:
- childhood acute lower respiratory infections (ALRI),
- chronic bronchitis (long-term cough and phlegm) and
- chronic obstructive lung disease (narrowing of airways in the lung),
- Indoor air pollution (IAP) in developing countries may also increase the risk of other important child and adult health problems, such as
- low birth weight,
- perinatal mortality (stillbirths and deaths in the first week of life),
- asthma, and middle ear infection in children,
- nasopharyngeal and laryngeal cancer, and
- cataract in adults
Women normally continue their usual work during pregnancy, so the unborn child is exposed as the mother continues her activities in the polluted kitchen. After birth, the young child typically stays very close to its mother until s/he is able to walk, so being exposed directly and increasing the risk of a range of serious health problems.
Open fires, stoves and lamps all pose a significant risk of burns for children. Kerosene,although a cleaner fuel, carries the risk of fire if the stove or lamp is knocked over or if it is drunk by mistake.In addition to this, there are a range of issues encompassing the use of women's time, injuries associated with the collection and carrying of fuel (mainly wood), use of fires and smoke in the home (food preservation, control of insects), opportunities for small scale commercial activities, effects on the local and global environment and so on which can also impact - directly or indirectly - on health (WHO, 1992).
Although these health outcomes do not result from human exposure to IAP, efforts to control that exposure will impact on these other consequences. For example, an additional benefit of the transition from open fires to enclosed stoves or alternative fuels may be to reduce the incidence of serious burns.
Lack of access to more modern fuels and appliances limits the quality of life and opportunities for income generation in a variety of ways. Lighting may be provided only by the fire, candles,or simple kerosene wick lamps which can be a significant source of pollution. Fumes from kerosene lamps in poorly ventilated houses are a serious health problem in much of the world where electricity is unavailable. It is estimated that people who rely on kerosene inhale the equivalent of two packs of cigarette smoke per day. In addition, kerosene lamps are a serious fire hazard in the developing world, killing and maiming tens of thousands of people each year. Solar electric light is entirely safe, and improves the indoor air quality of rural households that previously relied upon kerosene.
Electric light helps to increase literacy because people can read after dark more easily than they can by candlelight or a kerosene lamp. School work improves and eyesight is safeguarded Dependence on biomass fuels can affect the well-being of children in other ways. For example, it is not uncommon for older children to help their mothers in collecting fuel, thus missing school attendance and also being exposed to the risk of physical injury.
How can we help the rural population to breathe easily and get rid of the burden of diseases due to Indoor Air Pollution?
Ideally, a range of interventions can be used to reduce exposure to indoor air pollution. These are:
- Smoke removal - Flues attached to stoves, hoods and chimneys to remove smoke.
- Housing design - Changes to kitchen design to increase ventilation and control the distribution of pollution.
- Fuels -promoting fuel-switching to alternatives such as kerosene or LPG.
- Changing from traditionally designed cookstove to the improved cookstoves which reduce emissions, through better combustion and more efficient heat transfer. Stoves with longer life-span.
- Using solar energy or other energy sources for lighting of their homes and space heating
- Promoting awareness of long-term health effects on the part of users. This may lead to people finding ways of minimizing exposure through better kitchen management and infant protection
- Local microcredit facilities for the upfront costs of switching to gaseous fuels, examination of targeted (as opposed to across-the-board) subsidies to enable low income households to switch, income generation opportunities
- Training - to develop skills and expertise for stove development, improved housing design, and better education about health risks.
An estimated 500,000 women and children die in India each year due to IAP-related causes-this is 25 percent of estimated IAP-related deaths worldwide India currently bears the largest number of indoor air pollution (IAP)-related health problems in the world, with 75 percent of its households burning wood, dung, and crop residues-the "traditional" biomass fuels. traditional biomass fuels accounting for more than 50 percent of India's total energy supply, and more than 80 percent of household energy supply Women from poor families, in particular, suffer from severe health problems due to extended exposure to biomass smoke while cooking with traditional stoves, Exposure to biomass smoke increases the risk of acute respiratory infection (ARI) in children under five years of age.
Children in The Gambia found riding on their mothers' backs as they cooked over smoky cookstoves were six times more likely to develop ARI than unexposed children. women exposed to wood smoke for many years faced 75 times more risk of acquiring chronic lung disease, about the level of risk that heavy cigarette smokers face, than women not exposed to wood smoke.
Exposure to high indoor smoke levels has been linked to pregnancy-related problems such as stillbirths and low birth weight in studies in Latin America, Asia, and Africa. It has also been associated with blindness (attributed to 18 percent of cases in India) and immune system depression.
ContributorsGrant Ballard-Tremeer 21 August 2003
Dr Karabi Dutta 19 September 2003