ABSTRACT
A study of indoor was carried out on 615 different building in Rayong Province, Thailand, using an activated charcoal canister for sample collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, varying in concentrations from 4.00 to 74.15 becquerels/cubic metre (13.23+8.97 Bq.M-3). Although the levels of radon encountered were well below the safety threshold of 148 Bq.M-3 established by the U.S. Environmental Protection Agency, there were statistically significant difference between some districts. With regard to the type, age and ventilation status of the buildings, and the occupant’s practice of smoking indoor, the findings of this investigation do not warrant a conclusion that would support the notion of these factors contributing to, or being mutually associated with, indoor gaseous concentrations of radon.
ABSTRACT
A study of indoor radon was carried out on 1,024 different buildings in Samutprakarn province, Thailand, using an activated charcoal canister for sample collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, varying in concentration from 4.00 to 47.51 Bequerels/cubic metre (7.47+4.69 Bq.m-3). Although the levels of radon encountered were well below the safety threshold of 148 Bq.m-3 established by the U.S. Environmental Protection Agency, there were statistically significant differences between some districts. With regard to the type, age and ventilation status of the buildings, and the occupants’ practice of smoking indoors, the findings of this investigation do not warrant a conclusion that would support the notion of these factors contributing to, or being mutually associated with, indoor gaseous concentrations of radon.
ABSTRACT
During the months of December 1997 and January 1998, a study of indoor radon was carried out on 786 different buildings in 13 districts of Lampang Province in northern Thailand, using the charcoal canister method. The survey revealed the presence of radon gas inside all buildings investigated, varying in concentration from 4.00 to 176.73 becquerels/cubic metre (32.41+21.14 Bq.m-3); an elevated concentration over 150 Bq.m-3 was encountered in only one house in Muangpan district. Although the other measurements did not reveal indoor radon levels exceeding the safety threshold, the prevalence of high levels within normal range was detected among the building in the adjoining four districts (Amphur Muangpan, Amphur Hangchat, Amphur Jaehom and Amphur Koa-ka). With regard to the type, age and ventilation status of the buildings, and the practice of smoking indoors, the findings of this investigation do not conclusively support the notion of their contributing to, or being mutually associated with, indoor gaseous concentrations of radon.
ABSTRACT
During the months of July and August 1997, a survey to determine the existence of indoor radon was carried out, using an activated charcoal technique, in 474 different buildings in Nakornpathom Province. The presence of radon gas was encountered inside all the buildings investigated, varying in concentration from 4.00 to 86.40 Bq.m-3 (13.45 + 9.23 Bq.m-3). With regard to the type, age and ventilation status of the buildings, and the practice of smoking indoors, the findings do not conclusively support the notion of their contributing to, or mutually associated with, indoor gaseous concentrations of radon.
ABSTRACT
A study of indoor radon was carried out on 1,052 different buildings in Songkla Province, Thai-land, using an activated charcoal canister for sample collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, varying in concen-tration from 2.14 to 86.10 Bequerels/cubic metre (16.15 + 11.97 Bq.m-3). Although the levels of radon encoun-tered were well below the safety threshold of 148 Bq.m-3 established by the U.S. Environmental Protection Agency, a trend was detected suggesting that high levels within the normal range are prevalent in certain areas of the province. The phenomenon will be investigated in the next setting. With regard to the type, age and ventilation status of the buildings, and the practice of smoking indoors, the findings of this investigation do not conclusively support the notion of their contributing to, or being mutually associated with, indoor gaseous concentrations of radon.
ABSTRACT
Measurement of radon was carried out on seven different floors of a 32-storey glass-faced building. It revealed the presence of relatively comparable amounts of radon on every one of the floors investigated; however, the concentrations (4.00-14.53 Bq/m3) did not exceed the safety threshold. Based on the result of a previous investigation showing significant concentrations of radon in concrete buildings, it is imputed from the finding of the present study that the type of glass used as a building material in this case was unlikely to be an additional source of radon.
ABSTRACT
A study of indoor radon was carried out on 188 different building in 3 districts (Amphurs Kangkoi, phrabudhabat and Baanmoh) of Saraburi Province in Central Thailand, using an activated charcoal canister for gaseous collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside al the buildings investigated, ranging in concentrations from 4.00 to 33.66 Bequerels/cubic metre. The safety threshold for indoor radon, according to the U.S.Environmental Protection Agency, is 4 pCi/l (equivalent to 148 Bq.m-3).
ABSTRACT
A study of indoor radon was carried out on 319 different buildings in five districts (Amphurs Muang, Phuwiang, Khou-suankwan, ubolrat and Nampong) of Khonkaen Province in northeastern Thailand, using an activated charcoal canister for gaseous collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, with overall concentrations being 15.33 + 22.13 bequerels/cubic metre and the prevalence rate of elevated values being 0.94 percent. The prevalence f higher indoor radon concentrations in Amphur Phuwiang (32.18+ 44.05) Bq.m-3) differs statistically from the concentrations encountered in the four other districts. In considering the age of the buildings and the type of building materials, the differences in indoor radon concentrations were not statistically significant. Indoor cigarette smoking and the inappropriate ventilation of the buildings appeared to relate to the higher radon concentrations.
ABSTRACT
A study of indoor radon was carried out on 271 different buildings in the districts (Amphurs Thalang, Muang and Kratoo) of Phuket Province in Southern Thailand, using an activated charcoal canister for gaseous collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, varying in concentration from 4 to 82.50 Bequerels/cubic metre (14.09 + 11.48 Bq.m-3), i.e., well below the threshold limit of 148 Bq.m-3 established by the American Environmental Protection Agency. The results of measurement of radon concentrations in Amphur Kratoo (22.27 + 18.93 Bq.m-3), Amphur Thalang (14.45 + 10.11 Bq.m-3), and Amphur Muang (10.25 + 5.95 Bq.m-3) showed a marked statistically significant difference (p < 0.005). In considering the age of the buildings (less than 1 year, 1-5 years and over 5 years old), types of building materials (concrete, wood, zinc sheeting and glass) and the apprarent difference of ventilation, the differences in indoor radon concentrations were not statistically significant (P > 0.05). Indoor cigarette smoking did not affect indoor radon concentrations (p = 0.072).
ABSTRACT
A study of indoor radon was carried out on 287 different buildings in four districts (Amphur Muang, A. Tha Muang, A. Tha Maka and A. Phanomthuan) of Kanchanaburi Province, Thailand, using an activated charcoal canister for sample collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, with overall concentrations being 125.38 + 145.43 Bq.m-3 and the prevalence rate of elevated values being 31.70 percent. Concentrations of 131.14 + 116.36 Bq.m-3 with a 32.39 percent prevalence rate were obtained in Amphur Muang (71 buildings) ; 98.31 + 91.36 Bq.m-3 with a 22.41 percent prevalence rate in Amphur Tha Muang (58 buildings) ; 160.35 + 95.30 Bq.m-3 with a 56.66 percent prevalence rate in Amphur Tha Maka (60 buildings) ; 115.82 + 202.10 Bq.m-3 with a 21.24 percent prevalence rate in Amphur Phanomthuan (98 buildings). The higher prevalence at Amphur Tha Maka differs statistically from the prevalence encountered in the three other districts. In considering buildings constructed less than five years previously and those five or more years old, there were no statistically significant differences with regard to both the radon concentrations and the prevalence rate of elevated concentrations. There was evidence suggesting that sources of indoor radon are both the soil and construction materials. Buildings with good ventilation (e.g., houses built on high posts, and those with doors and windows frequently opened) showed somewhat less accumulation of indoor gas, without statistically significant difference (P>0.05).
ABSTRACT
Fifty-four hourses, mostly in Bangkok and Nonthaburi, where 54 lung cancer patients had lived for same time were selected for investigating the presence of indoor radon by the charcoal canister method. In only four of these houses were radon level higher than the normal threshold level of 150 Bq.m (i.e. 153, 160, 172 and 283 Bq.m). Thus, the prevalence of elevated radon concentrations was a mere 7.40 percent in contrast with 22.16 percent found in the general survey. Although this finding would apparently suggest a negative relationship between indoor radon concentrations and lung cancer, it is possible that those patients had been exposed earlier to high radon concentrations, perhaps when the buildings were still new. It should be remembered also that exposure to even low radon concentrations dose not rule out the potential hazard of this radioactive gas as a cause of lung cancer. Most houses in this study (92.60%) were constructed of concrete and more than 5 years old. Therefore, it is not surprising to encounter such low radon levels, since rates are usually higher in newer buildings.