Analysis of polybrominated diphenyl ether and tetrabromobisphenol A in plastic samples in Mongolia

This study was conducted to determine brominated flame retardants (BFRs) in electronic products in view compliance with the Restriction of Hazardous Substances (RoHS) and initiated by activities for implementation of the Stockholm Convention. Brominated flame retardants (BFRs) are synthetic additives mainly used in electrical and electronic appliances and in construction materials. Total 16 plastic casing samples were tested for threshold levels of polybrominated ethers. According the XFR results, the concentration of cadmium, lead, mercury and chromium were found below than Maximum Concentration Value (MCV) of RoHS, while the concentration of total bromine was exceeded the standard limitations in the samples. Only 1 out of the 16 plastic samples contains DecaBDEs while Tetrabromobisphenol (TBBP-A) is the major brominated flame retardants. However by the presence of one sample the average concentration of DecaBDE was above the RoHS limit of 1000 ppm as found in studies in other countries.DOI: http://doi.dx.org/10.5564/mjc.v15i0.317 Mongolian Journal of Chemistry 15 (41), 2014, p27-3

Relationship between dynamics of modern glaciers of the Mt. Munkhkhairkhan (Mongolian Altai) and climate

Mt. Munkhkhairkhan is the most crucial region for understanding climate and glaciation changes in Mongolia. This study investigated the relationship between glacial area changes and the climate elements of Mt. Munkhkhairkhan in the Mongolian-Altai Mountains using a remote sensing approach, in-situ observations, the Mann–Kendall (MK) test, Innovative Trend Analysis Method (ITAM), Sen’s slope estimator test, and statistical analysis. The study results showed that for the last 30 years, the annual average air temperature of Mt. Munkhkhairkhan has been slightly increasing. Total annual precipitation (mainly snow) in the mountain area decreased from 1990 to 2000, but since 2000, a significant increase in precipitation levels has appeared. For the last 30 years, the glacial area has decreased by 32% to 11.7 km2. Multiple regression results showed a strong correlation between Temperature, Precipitation, and Glaciers (Multiple R = 0.69, R2 = 0.48). Ruther indicated that Temperature (t = −2.332, p = 0.036) and Precipitation (t = −3.212, p = 0.007) were significant predictors in the model. Air temperature and precipitation explained 48 percent of the change in the glacier area, and R = 0.69 is a strong correlation. The glaciers and snow area in the study area have changed due to climate warming and precipitation changes and are located in arid and semi-arid regions of Central Asia. This study of Mt. Munkhairkhan shows that climate change significantly impacts glaciers and snow

In Memoriam, Academician Prof. Dr. Osor Shagdarsuren (1929-2010)

Academician, Professor Osor Shagdarsuren passed away due to apoplexy on Tuesday, February 2, 2010, at the age of 81. He was one of the most respected Mongolian ornithologists, biologists, and educators. The Mongolian scientific community has lost one of its greatest members, the premier Mongolian ornithologist

Prevalence and Determinants of QuantiFERON-Diagnosed Tuberculosis Infection in 9810 Mongolian Schoolchildren.

BACKGROUND: There is controversy regarding the potential influence of vitamin D deficiency, exposure to environmental tobacco smoke, BCG vaccination, season, and body habitus on susceptibility to Mycobacterium tuberculosis (MTB) infection. METHODS: We conducted a cross-sectional analysis to identify determinants of a positive QuantiFERON-TB Gold (QFT) assay result in children aged 6-13 years attending 18 schools in Ulaanbaatar, Mongolia. Data relating to potential risk factors for MTB infection were collected by questionnaire, physical examination, and determination of serum 25-hydroxyvitamin D (25[OH]D) concentrations. Risk ratios (RRs) were calculated with adjustment for potential confounders, and population attributable fractions (PAFs) were calculated for modifiable risk factors identified. RESULTS: Nine hundred forty-six of 9810 (9.6%) participants had a positive QFT result. QFT positivity was independently associated with household exposure to pulmonary tuberculosis (adjusted RR [aRR], 4.75 [95% confidence interval {CI}, 4.13-5.46, P < .001]; PAF, 13.1% [95% CI, 11.1%-15.0%]), vitamin D deficiency (aRR, 1.23 [95% CI, 1.08-1.40], P = .002; PAF, 5.7% [95% CI, 1.9%-9.3%]), exposure to environmental tobacco smoke (1 indoor smoker, aRR, 1.19 [95% CI, 1.04-1.35]; ≥2 indoor smokers, aRR, 1.30 [95% CI, 1.02-1.64]; P for trend = .006; PAF, 7.2% [95% CI, 2.2%-12.0%]), and increasing age (aRR per additional year, 1.14 [95% CI, 1.10-1.19], P < .001). No statistically significant independent association was seen for presence of a BCG scar, season of sampling, or body mass index. CONCLUSIONS: Vitamin D deficiency and exposure to environmental tobacco smoke are potentially modifiable risk factors for MTB infection

Vitamin D supplements for fracture prevention in schoolchildren in Mongolia: analysis of secondary outcomes from a multicentre, double-blind, randomised, placebo-controlled trial.

BACKGROUND: Vitamin D supplementation has been shown to increase total hip areal bone mineral density in healthy children and adolescents. We aimed to investigate whether supplementing schoolchildren living in Mongolia with weekly vitamin D3 for 3 years affected fracture risk. METHODS: We did a multicentre, double-blind, randomised, placebo-controlled trial across 18 public schools in Ulaanbaatar, Mongolia. Schoolchildren were eligible if they were aged 6-13 years at screening, had a negative QuantiFERON-TB Gold In-tube assay (QFT) result, were not hypersensitive to vitamin D or immunocompromised, did not use vitamin D supplements, did not have clinical signs of rickets, and had no intention of leaving Ulaanbaatar within 3 years. Participants were randomly assigned (1:1) to receive either vitamin D (oral dose of 14 000 international units [IU] vitamin D3, once per week) or placebo for 3 years using permuted block randomisation stratified by school of attendance. Participants, care providers, and all trial staff were masked to group assignment during the intervention. Prespecified secondary outcomes were incidence of fractures and adverse events, ascertained using questionnaires. The fracture and safety analyses included participants who completed at least one follow-up fracture questionnaire. We estimated adjusted risk ratios (RRs) and 95% CIs using generalised linear models with binomial distribution and a log link function with adjustment for school of attendance. The trial is registered with ClinicalTrials.gov, NCT02276755, and the intervention ended in May, 2019. FINDINGS: Between Sept 2, 2015, and March 20, 2017, 11 475 children were invited to participate in the study and 8851 were recruited and randomly assigned to receive either vitamin D (n=4418) or placebo (n=4433). 8348 participants were included in the fracture and safety analyses (4176 [94·5%] in the vitamin D group and 4172 [94·1%] in the placebo group). Of these, 4125 (49·4%) were female, 4223 (50·6%) were male, and 7701 (92·2%) were of Khalkh ancestry. Median age was 9·2 years (IQR 8·0-10·7) and 7975 (95·5%) participants had baseline serum 25-hydroxyvitamin D concentrations less than 50 nmol/L. During a median follow-up of 3·0 years (IQR 2·9-3·1), 268 (6·4%) participants in the vitamin D group and 253 (6·1%) in the placebo group reported one or more fractures (adjusted RR 1·10, 95% CI 0·93-1·29; p=0·27). Incidence of adverse events did not differ between study groups. INTERPRETATION: Oral vitamin D supplementation at a dose of 14 000 IU/week for 3 years was safe, but did not influence fracture risk in schoolchildren living in Mongolia who had a high baseline prevalence of vitamin D deficiency. FUNDING: US National Institutes of Health