The Problem of Indoor Air Pollution

acute respiratory infectionBesides diarrheal diseases, acute respiratory infection (ARI) constitutes one of the major groups of causes of death among children in developing countries and therefore globally. According to estimates for 2000 to 2003 presented in the 2005 World Health Report, acute respiratory disease accounts for 19% of total deaths in children < 5 years of age, making ARI the second-most-common cause of death in that age group, after neonatal causes, and slightly ahead of diarrheal diseases. While ARI contributes 2 to 4% of deaths in children < 5 years of age in the low-mortality member states, these causes contribute 19 to 21% of child deaths in the Eastern Mediterranean, Africa, and South East Asia regions, and 12 to 14% in the high-mortality countries of Europe, the Americas, and the Western Pacific region.

Many studies have been undertaken to establish the magnitude of the ARI problem in various countries and to study the effects of immunization and improved case management, but fewer have tried to study specific risk factors with a view to intervention at a primary stage. The focus of this article is not on the various etiologies or management of potentially fatal ARIs. Instead, it lies on the empirical studies of the relation between incidence or mortality from such diseases and one of the most common and most strongly poverty-related risk factors: indoor air pollution. The traditional use of biomass fuels (ie, agricultural wastes, animal dung, and firewood) has repeatedly been identified as a problem, as a cause of soil degradation, of deforestation, and as a major source of indoor air pollution. Yet, attempts to introduce alternatives to these traditional practices have not proved to be sustainable in the long term because these are the cheapest fuels available to the poor in the developing world, and also since building the traditional fireplace requires neither ready cash nor government support programs worked out together with Canadian Health&Care Mall.

As an illustration, parallel to the literature overview, we include the case of acute respiratory disease and mortality among children within a health and demographic surveillance project in Butajira in central Ethiopia. In a study from Butajira published in 1994, Shamebo et al reported ARI as cause of death as determined by verbal autopsy (VA) in 28% of 306 deaths in children < 5 years old between October 1988 and September 1989. A later study in Butajira to evaluate VA procedures in demographic surveillance reported pneumonia/sepsis as cause of death in 25% of deaths in the 1-to 14-year age group from 2003 to 2004.

Indoor Air Pollutants From Biomass Fuels

Uncontrolled exposure to indoor air pollution occurs in most poor communities. The main cause is the use of cheap or free, readily available fuels such as sticks, crop residues such as maize and sorghum stalks, animal dung and, less commonly, charcoal in open, unvented fireplaces inside the home. The typical fireplace is an earth hearth on the floor with three stones or clay props to carry a pot (Fig 1). Use of cleaner fuels, such as kerosene or butane, is mostly too expensive, both in terms of investment in equipment and in terms of the fuel cost itself. There are also strong traditions that regulate both the type of hearth and the use of fuels.

As smoke, pollution from biomass fuel combustion is a complex mixture of gases and suspended particles. Among the gases, carbon dioxide, water vapor, oxides of nitrogen, and carbon monoxide are the most dominant, but a large number of organic compounds occur in the smoke in proportions relating to both fuel type and conditions of combustion, including temperature. The particles consist of inorganic salts, carbon, and hydrocarbons in mixtures depending on fuel and combustion conditions. While the larger molecules of polycyclic hydrocarbons have been implicated in cancer causation, the focus in studies of indoor air pollution in relation to ARI has been on nitrogen dioxide and respirable particulate matter, mainly the smallest fraction (particulate matter with aerodynamic diameter < 10 ^m [PM10]).

Figure 1. A traditional mud hearth in Butajira.

March 29, 2016 Category: Respiratory Care