IDENTIFICATION OF NOVEL BIOMARKERS FOR LUNG CANCER RISK IN HIGH LEVELS OF RADON BY PROTEOMICS: A PILOT STUDY

Radon is the second most important risk factor for lung cancer after tobacco smoking. In Chiang Mai, Thailand, the values of indoor radon activity concentrations are considerably higher than global average values and it is a highest level among East Asian countries. The aim of our study is to identify novel biomarkers for lung cancer risk in high radon areas using a proteomic approach. In our transitional study, a total of 81 participants of non-smokers were examined, consist of 25 lung cancer patients (LC), 16 healthy controls from low levels of natural radiation areas (LLNRA) and 40 healthy controls from high levels of natural radiation areas (HLNRA). The results showed that a total of 799 differentially expressed proteins were identified. Among these, a total of 25 proteins were observed in both LC and HLNRA, but not in LINRA. Owing to the results obtained from this study, we also point out the research direction regarding the validation of some new candidate protein as a biomarker to screen population with high risk for lung cancer in the area with high levels of radon.

Characteristics of indoor radon and its progeny in a Japanese dwelling while using air appliances

Characteristics of radon and its progeny were investigated in different air conditions by turning four types of indoor air appliances on and off in a two-story concrete Japanese dwelling. The four appliances were air conditioner, air cleaner, gas heater and cooker hood. The measurements were done using two devices: (1) a Si-based semiconductor detector for continuous measurement of indoor radon concentration and (2) a ZnS(Ag) scintillation counting system for equilibrium-equivalent radon concentration. Throughout the entire experiment, the cooker hood was the most effective in decreasing indoor radon concentration over a long period of time and the less effective was the air conditioner, while the air cleaner and gas heater did not affect the concentration of radon. However, the results measured in each air condition will differ according to the lifestyles and activities of the inhabitants. In this study, indoor radon and its progeny in a Japanese dwelling will be characterised by the different air conditions.

Comparative dosimetry for radon and thoron in high background radiation areas in China

The present study focuses on internal exposure caused by the inhalation of radon and thoron progenies because the internal exposures have not yet been clarified. For their dose assessment, radon, thoron and thoron progeny concentrations were measured by passive monitors over a long period (for 6 months). Consequently, radon, thoron and equilibrium equivalent thoron concentrations were given as 124 ± 78, 1247 ± 1189 and 7.8 ± 9.1 Bq m(-3), respectively. Annual effective doses are estimated to be 3.1 ± 2.0 mSv for radon and 2.2 ± 2.5 mSv for thoron. Total dose are estimated to be 5.3 ± 3.5 mSv a(-1). The present study has revealed that the radon dose was comparable with the thoron dose, and the total dose was ∼2 times higher than the worldwide average.

Baseline data of naturally occurring radionuclides in some native vegetables and fruits in Southern Thailand

The aim of this study was to provide the baseline data information on natural radioactivities in vegetables and fruits produced and consumed locally in the areas of potential nuclear power plant sites in Thailand. Four provinces (Prajuab-Kirikhan, Chumphon, Surat-Thani and Nakhon-Si-thammarat) were selected for collection of native vegetables and fruits samples, together with their corresponding soils. The activities of (226)Ra, (228)Ra, (40)K and (210)Po were determined in all these samples. The obtained results for (226)Ra, (228)Ra, (40)K and (210)Po for all vegetable and fruit samples were in the range of 1-34, 1-108, 32-4392 and 0.2-47 Bq kg(-1), respectively, which were much lower than those obtained for their corresponding soils.