Exposure to airborne asbestos in thermal power plants in Mongolia

Background:

Coal-fired thermal power plants (TPPs) in Mongolia use various types of asbestos-containing materials (ACMs) in thermal insulation of piping systems, furnaces, and other products.Objective: To investigate the occupational exposure of insulation workers to airborne asbestos in Mongolian power plants.

Methods:

Forty-seven air samples were collected from four power plants in Mongolia during the progress of insulation work. The samples were analyzed by phase contrast microscopy (PCM) and transmission electron microscopy (TEM).

Results:

The average phase contrast microscopy equivalent (PCME) asbestos fiber concentration was 0.93 f/cm³. Sixteen of the 41 personal and one of the area samples exceeded the United States Occupational Safety and Health Administration (US OSHA) short-term exposure limit of 1.0 f/cm³. If it is assumed that the short-term samples collected are representative of full-shift exposure, then the exposures are approximately 10 times higher than the US OSHA 8-hour permissible exposure limit of 0.1 f/cm³.

Conclusion:

Power plant insulation workers are exposed to airborne asbestos at concentrations that exceed the US OSHA Permissible Exposure Limit. Action to mitigate the risks should be taken in Mongolia.     

Occupational lung diseases and the mining industry in Mongolia

Mining production has accounted for around 50% of the gross industrial product in Mongolia since 1998. Dust-induced chronic bronchitis and pneumoconiosis currently account for the largest relative share (67.8%) of occupational diseases in Mongolia, and cases are increasing annually. In 1967-2004, medically diagnosed cases of occupational diseases in Mongolia numbered 7,600. Of these, 5,154 were confirmed cases of dust-induced chronic bronchitis and pneumoconiosis. Lung diseases and other mining-sector health risks pose major challenges for Mongolia. Gold and coal mines, both formal and informal, contribute significantly to economic growth, but the prevalence of occupational lung diseases is high and access to health care is limited. Rapid implementation of an effective national program of silicosis elimination and pneumoconiosis reduction is critical to ensure the health and safety of workers in this important sector of the Mongolian economy.     

Analysis of incidence rates of occupational diseases in Mongolia, 1986-2006

The purpose of this study was to determine incidence rates and time trends of major occupational diseases in Mongolia. We retrieved information about all 4598 patients from 1986 to 2006 who were diagnosed and registered with occupational diseases by the National Center of Workplace Conditions and Occupational Diseases. There was an increasing trend for new cases as well as for incidence rates of reported occupational respiratory diseases (ORD), musculoskeletal disorders (MSD), cardiovascular diseases, skin diseases, toxic hepatitis, and noise-induced hearing loss. Such a trend may result from both rapid industrialization in Mongolia and increased recognition of occupational disease. Actions must be taken immediately to allocate more resources for prevention and early recognition of occupational diseases, establishment of a comprehensive hazard communication system, and enforcement of all regulations. Key words: occupational diseases, incidence rate, epidemiology, Mongolia.     

An assessment of air pollution and its attributable mortality in Ulaanbaatar, Mongolia

Epidemiologic studies have consistently reported associations between outdoor fine particulate matter (PM_2.5) air pollution and adverse health effects. Although Asia bears the majority of the public health burden from air pollution, few epidemiologic studies have been conducted outside of North America and Europe due in part to challenges in population exposure assessment. We assessed the feasibility of two current exposure assessment techniques, land use regression (LUR) modeling and mobile monitoring, and estimated the mortality attributable to air pollution in Ulaanbaatar, Mongolia. We developed LUR models for predicting wintertime spatial patterns of NO₂ and SO₂ based on 2-week passive Ogawa measurements at 37 locations and freely available geographic predictors. The models explained 74% and 78% of the variance in NO₂ and SO₂, respectively. Land cover characteristics derived from satellite images were useful predictors of both pollutants. Mobile PM_2.5 monitoring with an integrating nephelometer also showed promise, capturing substantial spatial variation in PM_2.5 concentrations. The spatial patterns in SO₂ and PM, seasonal and diurnal patterns in PM_2.5, and high wintertime PM_2.5/PM₁₀ ratios were consistent with a major impact from coal and wood combustion in the city’s low-income traditional housing (ger) areas. The annual average concentration of PM_2.5 measured at a centrally located government monitoring site was 75 μg/m³ or more than seven times the World Health Organization’s PM_2.5 air quality guideline, driven by a wintertime average concentration of 148 μg/m³. PM_2.5 concentrations measured in a traditional housing area were higher, with a wintertime mean PM_2.5 concentration of 250 μg/m³. We conservatively estimated that 29% (95% CI, 12–43%) of cardiopulmonary deaths and 40% (95% CI, 17–56%) of lung cancer deaths in the city are attributable to outdoor air pollution. These deaths correspond to nearly 10% of the city’s total mortality, with estimates ranging to more than 13% of mortality under less conservative model assumptions. LUR models and mobile monitoring can be successfully implemented in developing country cities, thus cost-effectively improving exposure assessment for epidemiology and risk assessment. Air pollution represents a major threat to public health in Ulaanbaatar, Mongolia, and reducing home heating emissions in traditional housing areas should be the primary focus of air pollution control efforts.