Introduction: Air pollution has become one of the major problems in socio-economic and health issues in Mongolia. Among the various hazards of particulate matter (PM) pollutants, microorganisms in PM2.5 and PM10 are thought to be responsible for various allergies and for the spread of respiratory diseases. Recent studies have shown that PM2.5 particles can cause chronic heart failure, heart arrhythmias, and strokes, as well as lung damage, cirrhosis, inflammation, cancer, cardiovascular disease, and metabolic disorders. Furthermore, some studies have concluded that PM2.5 particles in the environment are a risk factor for gastrointestinal, liver, colon, and lung cancer as well as it affects the growth and metastasis of various cancer cells caused by other factors. In our country, the health effects of air pollution and the relationship between the pathogenesis of cancer research are scarce. Therefore, the study of the effects of PM2.5 particles on cancer cell proliferation, migration (metastasis) can provide a significant role for cancer treatment, diagnosis, and prevention. Purpose: Determining the effects of PM2.5 particles on cancer cell proliferation, migration (metastasis) in in-vitro Material and Methods: A human liver cancer cell line (HepG2), human gastric cancer cell line (AGS) were obtained from the central scientific research laboratory in the Institute of medical sciences. HepG2, AGS cells were seeded at a concentration of 1*105 cells/mL in a culture flask and cultured in RPMI-1640 medium supplemented with 10% FBS, 1% antibiotic mix (penicillin, streptomycin) in a humidified atmosphere of 5% CO2 at 37 °C. The cytotoxic effect of PM 2.5 in AGS, HepG2 cells were evaluated by MTT, CCK8 assays. AGS, HepG2 cells were incubated in 96 well plates for 24h then treated with different concentrations (0, 5, 10, 25, 50 and 100 μg ) of Bayankhoshuu, Buhiin urguu, and Zaisan samples for 24h, respectively. Results: Concentrations of 10, 25, and 50 μg/ml of samples collected from the Bukhiin urguu and Zaisan in March increased HepG2 cell growth, while doses of 25, 50 μg/ml of samples collected from Bayankhoshuu in March and December increased HepG2 cell growth. Therefore, concentrations of 25 and 50 μg/ml of samples collected from Bayankhoshuu in March increased AGS cell growth, while concentrations of 25, 100 and μg/ml of samples collected in December increased AGS cell growth. However, no cytotoxic effect was observed in the sample collected from Zaisan in March, whereas the PM2.5 sample enhanced AGS cell growth in dose dependent manner in December.(p <0.05) Conclusion High levels of heavy metals were detected in samples collected in December from Bayankhoshuu, Bukhiin urguu and Zaisan of Ulaanbaatar. Concentration of 25 μg/ml of samples collected from the Bukhiin urguu and Zaisan in March increased HepG2 cell growth. Concentrations of 25 μg/ml of PM2.5 collected from three regions around Ulaanbaatar increased HepG2 and AGS cell migration.

BACKGROUND. Chronic rhino-sinusitis (CRS) is a common inflammatory disease of the nose and paranasal sinuses, especially after virus infections. It has a significant impact on patients’ quality of life. We aimed to evaluate the clinical value of low-level laser therapy (LLLT) forpediatric chronic rhino-sinusitis. METHODS. 30 patients 6-15 years old with CRS were divided into two groups: T1 were treated twice a week and T2 were treated five times a week for 2 treatment sessions within 2 weeks. Laser irradiation was delivered on 12 points over each maxillary and frontal sinuses with 30 seconds and the total treatment duration was 180 seconds. The evaluation was performed by a total symptom score based on SNOT-22 questionnaires of pre and after treatments. RESULTS. The total symptom scoreimproved significantly (p<0.15) in 27 cases. CONCLUSION. This study indicates that LLLT applied for 4 weeks improves symptoms in patients with CRS. LLLT is one of the most cost-efficient and painless treatment methods for pediatric rhino-sinusitis.