ABSTRACT
Radon is an odourless, colourless and tasteless gas and it is the first cause of lung cancer among non- smokers. The assessment of the level of radium in building materials helps in understanding the radiological implications. It has been observed that everyone has some levels of exposure to them. Therefore measurement of radium and radon in the soil samples are important from public health point of view. In the present work, radon exhalation rate and radium from soil samples have been measured through "Sealed Can technique" using LR-115 type II plastic track detector. Twenty two samples were collected from industrial area of Bulandshahr, Hapur and Meerut districts of Uttar Pradesh [India]. The radium concentration ranges from 9.2 to 18.7 Bqkg[-1] with an average value of 14.1 Bqkg[-1]. The area exhalation rate for radon ranges from 394.1 to 798.3 mBqm[-2] h[- 1] with an average value of 600.7 mBqm[-2] h[-1] and mass exhalation rate ranges from 15.1 to 30.7 mBqkg[-1]h[-1] with an average value of 23.1 mBqkg[-1]h[-1]. A strong correlation coefficient has been observed between radium concentration and radon exhalation rate. The values of radium concentration in all the soil samples were found to be lower than the limit 370 Bqkg[-1] as recommended by OECD, 1979. Hence, there is no matter of concern to the population living in this region
ABSTRACT
More than 50% of the total dose received by human beings from all sources of radiation [both from natural and manmade] comes from radon and its progeny which is responsible for lung cancer in many cases. In the present study, the measurements have been carried out by using twin chamber dosimeter cups with LR-115 type-II detectors. The value of track density of detectors gives the concentration of radon, thoron and their progeny in different modes. The average value of radon and thoron concentration was found 59 and 28 Bq/m[3], respectively. The inhalation dose was found to vary from 1.6 to 2.9 mSv/y. The average value of PAEC for radon and thoron was found 6.4 mWL and 0.75 mWL, respectively. Total annual exposure and annual effective dose varies from 0.23 to 0.39 WLM and 0.87 to 1.51 mSv/y respectively. The values of life time fatality risk was found to vary from 0.68 x 10[-4] to 1.18 x 10[-4]. These measurements show that the radon/thoron concentrations and annual effective dose received by the population of the area are well below the action level recommended by the International Commission on Radiological Protection [ICRP]
ABSTRACT
One hundred and fifty two eyes were treated for pterygium. Group I [72 eyes] were treated by the d'Ombrian Bare Sclera operating technique only whereas Group II [80 eyes] received triamciniolone acetonide 20 mg injection at the excision site after surgery. A recurrence rate of 40% was seen in Group I compared to 4% in Group II during a follow up period of 18 months. Raised intra-ocular pressure was noted in 9% of eyes requiring anti-glaucoma treatment for 9 to 18 weeks, in Group II only. The presence of a thin conjunctiva covered with very few vessels at the injection site following treatment could suggest a vasoconstrictor effect of triamcinolone and/or an inhibitory effect on vascular and fibroblastic proliferation, as the mechanism for preventing pterygium recurrence