Mongolia is located in a high latitude area of extreme continental weather with very low temperatures, which makes residents of gers or brick houses use wood or coal-burning stoves indoors for cooking and heating during the long winter. Heating in indoor living environments makes air pollution worse during the winter in Ulaanbaatar, Mongolia. Polycyclic aromatic hydrocarbons (PAHs) are byproduct emissions from various coal combustion sources, including coal-fired power plants, coal and wood stoves, and traffic emissions from vehicles. Urinary 1-hydroxypyrene (1-OHP) concentrations, a good biomarker of PAH exposure, were found to be significantly elevated among Mongolian children during the cold season, and for those living in ger areas, gers, or brick houses in Ulaanbaatar. Meanwhile, children’s urinary 1-OHP levels were associated with PAH co-pollutants SO2 and NO2, suggesting elevated 1-OHP levels may be attributable to PAH emissions from coal burning and traffic respectively, with indoor emissions from stoves further contributing to elevated 1-OHP in some children. These are the findings of a national study by researchers from National Taiwan University (NTU) and Health Sciences University of Mongolia. This study has been published in the February 2015 issue of Environmental Research.
The research team was led by Professor Dr. Chang-Chuan Chan (associate dean and director of the Global Health Center) in the College of Public Health, NTU, with his graduated Master’s degree student Ms. Yi-Ting Chen as first author. Total of 320 children aged 11-15 years were included in their study. Spot urine samples and questionnaires were conducted by Ms. Chen and collected three times from each subject in three seasons, September (warm) and December (cold) in 2011 and March (moderate) in 2012. Urinary 1-OHP was analyzed by high-performance liquid chromatography with fluorescent detection (HPLC/FLD). Generalized estimating equation (GEE) models were applied to estimate the seasonal and residential effects on 1-OHP levels, adjusting for demographic and environmental factors.
Their findings revealed that children who lived in gers or brick houses had higher urinary 1-OHP levels might be attributable by the use of wood and coal in indoor burning stoves for heating and cooking during the cold season. “Heating indoor living environments elevates air pollution and PAH exposure in Ulaanbaatar, Mongolia.” said Ms. Chen. Coal-fired power plants and traffic emission are also a potential source of PAH exposure in Ulaanbaatar. They used modeling SO2 and NO2 concentrations at children’s present home address to represent the air pollutants from coal consumption and traffic emission, respectively. “Both traffic and coal combustion were equally important in contributing to PAHs exposures of Mongolian children in Ulaanbaatar,” Prof. Chan pointed out.
The researchers hope their findings will promote the development of air pollution control policies and improve their air pollution problems in Ulaanbaatar, Mongolia. Furthermore, the bilateral cooperate program between Taiwan and Mongolia is a good beginning for public health research in international air pollution issues.