ArticlesCooking fuels and prevalence of asthma: a global analysis of phase three of the International Study of Asthma and Allergies in Childhood (ISAAC)
Introduction
Despite much research, little is known about the cause of asthma. The international study of asthma and allergies in childhood (ISAAC) has documented a wide variation in asthma prevalence across the world and has also detected evidence of a continuing increase, especially in low-income and middle-income countries.1, 2 The possible role of air pollution in the development of respiratory diseases is a major focus of research. Several studies have investigated the association between indoor air pollution and asthma and chronic obstructive pulmonary disorder (COPD).3, 4 In high-income countries, the use of gas appliances for cooking has been implicated as a cause of respiratory symptoms, particularly in women.5 The use of gas as cooking fuel has also been implicated as one of the factors that might explain the higher asthma prevalence in Chinese children in Hong Kong compared with children in other Chinese cities.6 However, results from the European community respiratory health survey of more than 10 000 respondents did not show any relation between the use of gas for cooking and obstructive respiratory symptoms.7
Exposures to domestic fire burning of coal and biomass such as wood, animal dung, and crop residues for cooking or heating are widespread, especially in rural areas of poor countries. According to WHO, at least half the world's population live in households in which solid fuels or biomass are the primary fuel for cooking, heating, or both.8, 9 In resource-poor countries, cooking with biomass is typically done on unvented stoves without any form of ventilation system.10 In India, biomass burning has been shown to be associated with increased respiratory symptoms in children.11 A nationwide study in India showed that exposure to the combustion of biomass and solid fuels was associated with an increased risk of asthma in women.12 A study of 508 adults in the USA also showed a positive association between asthma and exposure to cooking indoors with wood and coal.13 WHO estimated that indoor air pollution from the burning of biomass causes almost 2 million deaths annually.8 Because the burning of biomass fuel or the use of gas for cooking are potentially modifiable factors, the study of their relation with asthma and wheezing illnesses in children is important.
Many studies of the association between cooking fuel and asthma have been of low statistical power. Furthermore, estimation of the individual exposure presents a major challenge because the proximity to the sources of exposure, the duration of exposure, and accurate assessment of ventilation are not easily quantifiable in large studies. The existing evidence about the association between household air pollution from biomass burning and asthma is conflicting, with more consistent positive associations in children than in adults.14, 15, 16, 17, 18 We investigated the relation between asthma and the use of a range of cooking fuels in study centres around the world. Using standardised methods, phase one of ISAAC documented large variations in asthma prevalence across the world. Phase two included objective measurements including skin-prick test and bronchial challenge test, providing further support of the importance of environmental factors in the development of asthma. The results reported here are based on a detailed environmental questionnaire administered to children in 47 countries to test different cause hypotheses of asthma as part of the phase three ISAAC study.
Section snippets
Study design
ISAAC phase three is an expansion using the same study design of the first phase of ISAAC, findings from which showed a wide variation in the prevalence of childhood asthma and related atopic disorders across the world.1, 2, 19 The details of the study protocol are available elsewhere.2, 19 Briefly, written questionnaires were self-completed at school by secondary school students aged 13–14 years who were then, in most centres, shown a video questionnaire on wheezing symptoms. 244 734 (78%)
Results
Data were collected between 1999 and 2004. In the initial statistical models, there were 198 398 children aged 6–7 years from 70 centres in 29 countries (figure 1) and 314 309 children aged 13–14 years from 108 centres in 47 countries (figure 2). Table 1, Table 2 show the distribution of the use of different types of fuel for cooking by region for the two age groups (see appendix for the prevalence rates of the various health outcomes in relation to the use of different types of cooking fuel in
Discussion
The findings from this large multicentre survey show that the use of open fires for cooking is associated with symptoms of asthma and ever reported asthma in school children of two age groups: 6–7 years and 13–14 years. The associations were consistent between sexes. Furthermore, the associations were similar using three different validated methods to assess the symptoms of current wheeze or ever reported asthma (self-completed written questionnaire and video questionnaires for children aged
References (48)
- et al.
Worldwide time trends in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and eczema in childhood: ISAAC Phases One and Three repeat multicountry cross-sectional surveys
Lancet
(2006) - et al.
Chronic obstructive pulmonary disease in non-smokers
Lancet
(2009) - et al.
Association of respiratory symptoms and lung function in young adults with use of domestic gas appliances
Lancet
(1996) - et al.
Association between paracetamol use in infancy and childhood, and risk of asthma, rhinoconjunctivitis, and eczema in children aged 6–7 years: analysis from Phase Three of the ISAAC programme
Lancet
(2008) - et al.
A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010
Lancet
(2012) - et al.
Selected major risk factors and global and regional burden of disease
Lancet
(2002) - et al.
Indoor air pollution from biomass fuel smoke is a major health concern in the developing world
Trans R Soc Trop Med Hyg
(2008) Worldwide variation in prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema: ISAAC
Lancet
(1998)- et al.
Effects of smoking and solid-fuel use on COPD, lung cancer, and tuberculosis in China: a time-based, multiple risk factor, modelling study
Lancet
(2008) - et al.
Factors associated with difference in prevalence of asthma in children from three cities in China: multicentre epidemiological survey
BMJ
(2004)
The association of respiratory symptoms and lung function with the use of gas for cooking. European Community Respiratory Health Survey
Eur Respir J
Indoor air-pollution from solid fuel use
Fuel for life: household energy and health
National burden of disease in India from indoor air pollution
Proc Natl Acad Sci USA
Impact of domestic air pollution from cooking fuel on respiratory allergies in children in India
Asian Pac J Allergy Immunol
Effect of indoor air pollution from biomass and solid fuel combustion on prevalence of self-reported asthma among adult men and women in India: findings from a nationwide large-scale cross-sectional survey
J Asthma
Exposure to indoor biomass fuel pollutants and asthma prevalence in Southeastern Kentucky: results from the Burden of Lung Disease (BOLD) study
J Asthma
Home environment and asthma in Kenyan schoolchildren: a case–control study
Thorax
Indoor air pollution and asthma in hospitalized children in a tropical environment
J Asthma
Asthma and indoor environment in Nepal
Thorax
Effect of indoor air pollution from biomass combustion on prevalence of asthma in the elderly
Environ Health Perspect
Childhood asthma and indoor woodsmoke from cooking in Guatemala
J Expo Anal Environ Epidemiol
The international study of asthma and allergies in childhood (ISAAC): phase three rationale and methods
Int J Tuberc Lung Dis
The impact of the method of consent on response rates in the ISAAC time trends study
Int J Tuberc Lung Dis
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