Background: In this study, measurement of indoor radon and its progeny levels was carried out in Gas Turbine Power Station in Haryana ( India ), where natural gas is used as fuel. For comparison, the results of a study carried out in thermal power plant in Haryana are also presented. Radon being a ubiquitous air pollutant has global impact and its monitoring in the environment at work places is essential from health and hygiene point of view.

Materials and Methods: LR-115, Type- II (Kodak Pathe, France), plastic track detectors commonly known as solid state nuclear track detectors (SSNTDs) were used to measure the radon concentration over long integrated times. Alpha particles emitted from radon cause radiation damage tracks, which were subsequently revealed by chemical etching in NaOH. These alpha tracks registered were counted by optical microscope at suitable magnification and converted into radon concentration.

Results: The radon levels measured at various locations were moderate to high and thus unsafe from health point of view. The potential alpha energy concentration (PAEC), radon levels (EEC), annual exposure, annual effective dose in the Gas Turbine Power Plant varied from 4.14 mWL to 26.7 mWL, 38.3 Bq m^-3 to 247.6 Bq m^-3, 0.17 WLM to 1.10 WLM and 0.66 mSv to 4.25 mSv respectively.

Conclusion: In gas turbine power plant, the radon levels were found to be lower as compared with thermal power plant. In thermal power plant a lot of coal is being burnt which contains radionuclides. Coal fired plants release more radioactive waste which is hazardous into the air than gas power plants of equivalent capacity. Iran . J. Radiat. Res., 2003; 1(3): 133 - 137