Identifying indoor radon sources in Pa Miang, Chiang Mai, Thailand.

Radon is the leading source of lung cancer mortality after smoking in Chiang Mai, Thailand. Finding a source of carcinogens is one of the important measures for preventing the cancer risk for this region. Specific sites at Pa Miang, Doi Saket have the highest incidences of lung cancer and have a combination of factors that influence indoor radon concentration. Our study identified the sources of indoor radon within several houses. The results indicate that geological and topographic characteristics, including active faults and mountain terraces, are the main sources of indoor radon, especially for wooden houses. Besides building materials, the design of the houses, ventilation conditions, and lifestyle choices are all factors influencing indoor radon concentrations and its associated risk. Although radon levels (29-101 Bq m-3) and total indoor annual effective doses (0.9-3.8 mSv year-1) received from all sources at these sites have shown no significant health risk due to radon exposure , this investigation will be useful as a starting point to guide strategies to respond and prevent the risk of lung cancer, especially in Chiang Mai.

Bone mineral density at distal forearm in men over 40 years of age in Mae Chaem district, Chiang Mai Province, Thailand: a pilot study.

OBJECTIVE: To study the prevalence of bone mineral density (BMD) and osteoporosis in the distal forearm among Thai men over 40 years of age in Mae Chaem District, Chiang Mai Province, Thailand. METHODS: The subjects in this study were 194 Thai men, aged between 40 and 87 years who resided in Mae Chaem District, Chiang Mai Province, Thailand. Self-administered questionnaires were used for receiving the demographic characteristics information. BMD was measured by peripheral dual energy X-ray absorptiometry at the nondominant distal forearm in all men. RESULTS: The BMD was highest in the age-group 40-49 years and lowest in the age-group 70-87 years. The average T-score at the distal forearm was also highest in the age-group 40-49 years and lowest in the age-group 70-87 years. The BMD decreased as a function of age-group (p < .05). In contrast, the BMD increased as a function of weight (p < .05). Height had weak impact on the BMD in the distal forearm (p > .05). The percentage of osteopenia and osteoporosis are increased as a function of age-group in, while decreased in that of normal bone density. CONCLUSIONS: We found the prevalence of osteoporosis in men who resided in Mae Chaem District, Chiang Mai Province, Thailand.