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            Indoor Air Pollution                                                                            at a glance


Why is alleviating Indoor Air                              a three-stone open fire is wasted, which is a real
                                                           problem considering that poor families spend up to
Pollution a priority?                                      20% of their income on solid fuels and/or spend one
Indoor Air Pollution (IAP) is a major risk factor,         quarter of their time gathering wood.
accounting for about 4% of the global burden of
disease measured by disability adjusted life years         How large is the global burden of
(DALYs) lost. It is caused by the use of low-cost,         ill health from IAP?
widely available traditional energy sources such as
coal and bio-mass (wood, dung, crop residues) for          While acute exposure to smoke may result in carbon
cooking and home heating. Bio-mass is still the main       monoxide poisoning and death, most of the effects
source of energy for 60 to 90% of households in            occur as a result of long term exposure. There is strong
developing countries, about 3.5 billion people. The        evidence that chronic exposure to indoor air pollutants
health burden from IAP is greater in high-altitude rural   increases the risk of a range of respiratory illnesses,
areas and amongst poor families who tend to use            including acute lower respiratory infections (ALRI) in
cheap bio-mass and low quality coal fuels in primitive     children and chronic obstructive pulmonary disease
stoves without proper ventilation. Women and young         (COPD) in adults. In addition, chronic exposure to coal
children are at greatest risk because their gender         smoke results in increased risk for lung cancer.
roles and household responsibilities and behaviors--
cooking and spending a lot of time indoors--result in
high exposure to IAP (85% of all global particulate
exposure occurs indoors).

Bio-mass and coal, while cheap and readily
available, are extremely polluting. They pose serious
health hazards due to acute and chronic exposure to
particulates (PM10), sulfure and nitrous oxides (SO2,
NOX), carbon monoxide (CO), fluoride (coal),
aldehydes and para amino hydrocarbons (PAH).
Developing countries account for 77% of all global
particulate exposure, where numerous studies have
found that IAP levels are typically many times higher
than developed world standards for ambient air
quality. Concentration levels vary greatly depending
on the time of day, season and place of
measurement, especially for inhalable particulates
(<PM10) and CO levels.

Use of solid fuels, biomass or coal causes respiratory
and other illnesses. It also has implications for
household safety (burns and disfiguration, fire),
allocation and use of the time of household members,
especially women, and local ecology (hygiene, fire
hazards, ambient air pollution, etc.) Furthermore, IAP
is a proxy indicator of inefficient use of scarce          IAP hazards in homes: open fires and cigarette smoke.
sources of energy and household income and assets.         Source: Institute of Environmental Health and Engineering, Chinese Academy
For example, up to 85% of the energy generated by          of Preventive Medicine, 2000.



                                                                                                         September 2003
 Burden of disease attributable to 10 selected leading risk factors, by level of development
 and type of affected outcome

                                          Developing countries ­ high mortality
                          Underweight
                            Unsafe sex
 Unsafe water, sanitation and hygiene
        Indoor smoke from solid fuels
                        Zinc deficiency
                        Iron deficiency
                 Vitamin A deficiency
                        Blood pressure
                              Tobacco
                            Cholesterol
                                      0%          2%          4%          6%          8%      10%    12%        14%        16%
                                          Attributable DALYs (% of total 833 million DALYs)



                                          Developing countries ­ low mortality                GROUP I. Communicable diseases,
                                                                                              maternal and perinatal conditions and
                               Alcohol                                                        nutritional deficiencies
                        Blood pressure                                                                 Infectious and parasitic diseases
                              Tobacco                                                                  Maternal and perinatal conditions
                          Underweight                                                                  Nutritional deficiencies
                           Overweight                                                         GROUP II. Noncommunicable conditions
                            Cholesterol                                                                Cardiovascular diseases
       Low fruit and vegetable intake                                                                  Cancers
        Indoor smoke from solid fuels                                                                  Chronic respiratory diseases
                        Iron deficiency                                                                Neuropsychiatric disorders
 Unsafe water, sanitation and hygiene                                                                  Other noncommunicable conditions
                                      0%          2%          4%          6%          8%      GROUP III. Injuries
                                          Attributable DALYs (% of total 408 million DALYs)
                                                                                                       Unintentional injuries
                                                                                                       Intentional injuries

Source: World Health Report, 2002


According to the World Health Report (WHR) 2002                             80% of which occurs in Africa and South and South
about 36% of ALRI, 22% of COPD and 1.5% of                                  East Asia. Indoor Air Pollution ranks eighth globally
cancers of the trachea, lung and bronchus are caused                        among risk factors, and fourth in developing countries
by exposure to IAP. Other conditions attributed to IAP                      with high mortality, which make up 40% of the world
for which the evidence is emerging but still inconclusive                   population,after underweight, unsafe sex and unsafe
include increased susceptibility to asthma and middle                       water, sanitation and hygiene, but before micronutrient
ear infections in children, and tuberculosis, cataracts,                    deficiencies and tobacco. COPD and lung cancer are
and cancers of the nasopharynx and larynx in adults.                        the main causes of death associated with IAP in China
Two studies have also implicated indoor air pollution in                    whereas ARI account for more than 80% of the deaths
low birth weight and perinatal mortality. Finally, one                      and DALYs lost in India.
could include burns (although not directly related to
IAP), eye irritation, and fluorosis due to exposure to                      What can be done to alleviate
smoke from coal with high fluoride content through                          Indoor Air Pollution?
inhalation and ingestion.
                                                                            Eventually, most developing countries will move up the
Several reviews have tried to estimate the global                           energy ladder to liquid or natural gas, or electricity. But
burden due to use of solid fuels by applying disease                        this move is inhibited by poor people's low incomes
specific relative risks or odds ratios to global estimates                  and limited access to high quality fuel such as liquefied
of the number of households using solid fuels. WHR                          petroleum gas (LPG), natural gas or electricity. In fact,
2002 finds that 2.7% of the total global burden of ill                      use of biomass and coal have stagnated at around
health measured as DALY's is attributable to IAP, almost                    25% of all energy sources since 1975, and may even
 Many interventions have been shown to be effective in reducing indoor air pollution. These can be
 grouped into three categories:

 Intervention type               Intervention examples                    Key monitoring indicators

 technologies which aim at          better stove design                      Particulates (PM10) in the air in homes
 improved cooking/heating           better ventilation to reduce IAP         Carbon monoxide (CO in parts per
 devices, improved fuels, or        particulate levels in houses             million or ppm)
 reduced need for heating           switch to cleaner (but typically         Fluoride levels in food (for households
                                    more costly) fuels                       that use coal which contains fluoride)
                                    chemical treatment of some fuels,        Ideally, have beneficiaries wear a
                                    eg coal                                  device that measures direct exposure
                                    reduce size of fuel pieces,              to PM10 over a specified time period
                                    eg briquettes and pellets instead        (eg 24 hours) before and after the
                                    of large coal lumps                      intervention
                                    better insulation
                                    solar energy for boiling water

 technologies aimed at              partitions, walls or screens in
 improving the                      homes to separate cooking and
 living environment                 sleeping/living areas
                                    better ventilation or ducts, hoods
                                    to carry smoke and particulates
                                    outside the house

 behavioral change to reduce        reduce time spent in
 exposure and/or reduce             kitchen/cooking area
 smoke generation                   keep lids on pots while cooking
                                    proper stove maintenance
                                    and cleaning
                                    push fuel (esp plant stalks) deeper
                                    into stove so that less smoke
                                    "escapes" into the room
                                    keep children away from
                                    the smoke



be increasing with growing poverty and income               improved biomass stove program cost only $50­100
disparities. According to the World Energy Council,         per DALY saved, slightly higher than the provision of
biomass energy use is likely to reach the equivalent of     water in rural areas ($35 per DALY saved), but still
1.1­1.3 gigatones of oil by 2020. Even when energy          well within the cost-effective range (< $150­200 per
transition starts, most households continue to use a mix    DALY saved). However, before recommending
of modern and traditional fuels and energy sources to       changes in fuel source, technology and behavior, the
meet various household needs.                               implications for affordability, commercial viability,
                                                            socio-cultural acceptability, environmental impact and
Several intervention studies have shown that simply         long term sustainability need to be considered. Large-
switching from wood to charcoal, or installing better       scale community-based intervention trials are needed
stoves can reduce exposure to PM10 substantially and        to document cost-effectiveness, feasibility and long-
reduce ALRI incidence. These interventions appear to        term sustainability of multi-sectoral interventions.
be highly cost-effective. For example, in India one
The World Bank's role                                        Stove improvement programs need to include a
                                                             component to inform, educate and communicate
The World Bank is strategically well positioned for          the health, environmental, energy and financial
advocacy, and inter-sectoral research and interven-          consequences of indoor air pollution and how
tions to alleviate indoor air pollution in poor rural        improved stoves together with behavioral change
settings. The Bank has already spearheaded                   can lead to better health and household finances.
numerous initiatives to improve household energy use         Long-term sustainable solutions require full
through energy and rural development operations. An          participation from local government, NGOs, the
important lesson of experience is that interventions         commercial sector and local communities.
must be evaluated from several perspectives: health,
energy, environment, and cultural/social practices,
such as the ways in which homes are used. Recent
                                                          Selected sources for more
multi-sectoral intervention initiatives and advocacy
                                                          information:
efforts are underway in India, China, Guatemala and       People
other high-burden countries to improve access to
efficient and affordable energy through local design,        World Bank: Enis Baris (health), Kseniya Lvovsky
manufacturing and dissemination of low-cost stove            (environment), Todd Johnson (environment/energy)
technologies, modern fuel alternatives and renewable         WHO: Majid Ezzati, Nigel Bruce, Yasmin von
energy solutions.                                            Schirnding
                                                             UC Berkeley, Institute of Global Health: Kirk Smith
Best Practices and Implementation
Lessons Learned:
                                                          Key references
   Effectiveness will depend on three key considera-
   tions: (i) the policy and regulatory context;             von Schirnding Y, N Bruce, K Smith, G Ballars-
   (ii) making sure that all relevant sectors/perspec-       Tremeer, M Ezzati, and K Lvovsky, Addressing the
   tives are considered in interventions that aim to         Impact of Household Energy and Indoor Air
                                                             Pollution on the Health of the Poor--Implications for
   increase fuel efficiency, reduce health risks and
                                                             Policy Action and Intervention Measures,
   improve local ecology; and (iii) local community
                                                             Commission on Macroeconomics and Health
   involvement in technology design and application,         Working Paper WG5:12, July 2001
   especially with regard to stoves and ventilation.
                                                             Bruce N, R Perez-Padilla, and R Albalak, Indoor
   Improved stove design should be needs-based and           Air Pollution in developing countries: a major
   tailored to the local ecology and socio-economic          environmental and public health challenge, Bulletin
                                                             of the World Health Organization, 2000, 78(9):
   conditions of the community.                              1078-1092
   All interventions (or combinations of interventions)
   need to be customized to local circumstances.          Key websites
   Stove building and maintenance can create                 World Health Organization, World Health Report
   income-generating opportunities for the local             2002. http://www.who.int/whr/en/
   economy, and enable women especially to make
                                                             Indoor Air Pollution: Energy and Health for the
   more productive use of their time, earn higher
                                                             Poor. An ESMAP World Bank Initiative (Newsletter).
   incomes and gain financial independence.                  http://wbln1018.worldbank.org/sar/sa.nsf
   Subsidies can be offered as an incentive to adopt
   improved stoves as long as they are managed            Recent global event
   effectively and phased out gradually to limit
   continuous reliance on public funding.                    Global Health Council Conference, 27­30 May
                                                             2003, Washington, D.C. (www.globalhealth.org).
   Rural credit schemes can be an effective way to           The overall theme was "Our Future on Common
   promote demand and finance community-based                Ground: Health and the Environment", and IAP
   stove improvement schemes.                                was one of the sub-themes.



 Expanded versions of the "at a glance" series, with e-linkages to resources and more information, are
 available on the World Bank Health-Nutrition-Population web site: www.worldbank.org/hnp