| Summary: | 碩士 === 國立臺灣大學 === 職業醫學與工業衛生研究所 === 101 === Background：Ulaanbaatar, the capital city of Mongolia, is the most urbanized city of
the country. Many people live in gers, the traditional Mongolian dwellings, in crowded
areas called ger areas, in Ulaanbaatar. Previous studies have shown that air quality was
polluted by emissions from coals and woods used in gers and three coal-fired power
plants and the concentrations of heavy metals in PM10 were elevated in Ulaanbaatar.
However, no study on human exposure to air pollutants has been reported in
Ulaanbaatar yet. The purpose of this study is to evaluate children’s exposure to heavy
metals and identify potential sources of such exposures in Ulaanbaatar.
Methods：Our study subjects were 320 students aged from 11 to 15 years old in 6
schools in Ulaanbaatar. Spot urine samples and questionnaires were collected three
times for each subject in the non-heating season (September in 2011) and heating season
(December in 2011and March in 2012). Personal information and potential heavy
metals exposure-related factors were collected by questionnaire. The levels of urinary
heavy metals, including vanadium, chromium, manganese, nickel, copper, arsenic,
strontium, cadmium, mercury, thallium and lead, were analyzed by inductively coupled
plasma mass spectroscopy (ICP-MS). Generalized Estimating Equation (GEE) modes
were applied to estimate seasonal effects on urinary heavy metals levels, adjusting for
demographic and environmental factors.
Results：According to GEE models, we found that the urinary levels of cadmium and
lead of the children who live in gers were respectively 1.52 and 1.46 times higher than
those of the children living in apartments, after adjusting for age, gender, season, area,
smoking and insecticide use. Urinary levels of vanadium and chromium of the children
who live in brick houses were respectively 1.14 and 1.15 times higher than those of the children living in apartments. Urine cadmium and lead levels for children living in ger
areas were 1.24 and 1.23 times higher than those living in non-ger areas. In addition, we
found that urinary levels of copper and arsenic of the children in the heating season
were respectively 1.10 and 1.20 times higher than in the non-heating season after
adjusting for other exposure-related factors. By contrast, urinary levels of nickel and
cadmium of the children in the heating season were respectively 0.75 and 0.76 times
lower than in the non-heating season.
Conclusions：Mongolian children’s urinary cadmium and lead levels were significantly
increased for those living in ger areas or in gers in Ulaanbaatar. Air pollution was not
the only source of Mongolian children’s exposures to heavy metals.
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