Respiratory Health and Indoor Air Pollution at High Elevation

Abstract

In this research, the authors sought to provide experimental data on indoor air quality, and the resulting respiratory impact, for a high-elevation (4550 m), rural community in Ladakh, India. This community is of interest because the primarily nomadic residents burn biomass inside the home for heating and cooking. The concentrations of particulate matter (PM), endotoxin, and carbon monoxide were determined for 6 homes. Lung function data and induced sputum samples were collected for 9 female test-home subjects. In addition, lung function data were collected for 84 additional Ladakhi highlanders at this location. Sputum from 3 visiting scientists (sojourners) was collected and analyzed as well. The average PM concentration ranged from 2 mg/m 3 to 7 mg/m 3 , with 85% of the sampled PM sized as respirable. The average endotoxin concentration ranged from 2.4 ng/m 3 to 19 ng/m 3 , and average carbon monoxide levels ranged from 50 ppm to 120 ppm. Lung function values for the highlander population and the test-home subjects were equal to or greater than predicted, despite the highlanders' significant exposure to indoor pollutants. An induced sputum analysis revealed a significantly greater total inflammatory cell count (M ± SD, 10 5 cell/mg) in the Ladakhi natives than in the sojourners (107.5 ± 75.2 vs 7.1 ± 8.1, p .01). Although the high levels of indoor pollutants did not correlate with significant decrements in lung function, the induced sputum analysis revealed marked airway inflammation dominated by macrophages and neutrophils. It appears that augmented lung mechanics of this high-altitude population are adaptive to reduce the work of breathing; thus, decrements in lung function go undetected because the true predicted values are greater than expected.Keywords biomass combustion; high-altitude population; indoor air quality; lung functionThe World Health Organization estimates that 20% to 30% of all respiratory diseases are caused by ambient and indoor air pollution.1 Globally, indoor air contaminants are of Request for reprints should be sent to Jacky Ann Rosati, PhD, USEPA, Office of Research and Development, National Homeland Security Research Center, E-343−06, 109 TW Alexander Drive, Research Triangle Park, NC 27711. E-mail: rosati.jacky@epa.gov. HHS Public Access Author ManuscriptAuthor Manuscript Author ManuscriptAuthor Manuscript concern because nearly 50% of the world's population burns biomass for domestic purposes such as cooking and heating.1,2 In developing nations, indoor exposure to biomass combustion byproducts has been associated with an increased incidence of respiratory disease as well as an increased rate of mortality.3-12 The World Bank has estimated that indoor air pollution is responsible for almost half the burden of disease in developing countries.2,13 In India alone, it is estimated that 400,000 to 550,000 premature deaths can be contributed to the use of biomass fuels.14 In Ladakh, Indian Himalaya, research has shown a prevalence of chronic cough, chronic phlegm, nonoccupational...

Assessment of the Indoor Environment and Implications for Health in Roma Villages in Slovakia and Romania

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