STUDY ON CORRELATION BETWEEN OUTDOOR RADON CONCENTRATION AND SURFACE RADIATION DOSE IN A FORMER TIN MINING AREA
Zaharidah Abu Bakar2, Ahmad Saat1, Zaini Hamzah2, Norafizah Hashim2
1Institute of Science
2Faculty of Applied Sciences
Universiti Teknologi MARA Malaysia
40450 Shah Alam
Former tin mining areas are known to be disturbed by anthropogenic activities that change the structure composition of the soils. Naturally occurring radioactive material (NORM) especially those containing uranium tends to be higher in concentration in the area. The present study aims at determining the outdoor radon concentration as well as the correlation of between the radiation dose and the radon concentration at various points in the area. The study was carried out in one of the former tin mining area that has been converted to a training centre in Kampung Gajah, Perak. Radiation dose at measuring points were measured at surface level and at 1 m from the surface. Radon concentrations at selected points were monitored at hourly interval for twenty four hours period. Radiation dose were measured by using a Ladlum Radiation Survey meter, while radon gas were monitored by using Professional Continuous Radon Monitor Model 1027. The study found that the average outdoor radon concentration was about 0.7 pCi/L, but can reach a maximum value of 4.6 pCi/L. This is higher than the global average of 0.4 pCi/L. There is also a positive correlation between average outdoor radon concentration and radiation dose, with linear regression coefficients of R2 = 0.6323 and 0.5222 for surface dose and 1 m dose respectively. Thus, it can safely be said that majority of the radon gas in the study points originated from soils in the respective points, and not being transported from other places.
Keywords: Tin mining area, outdoor radon, radiation dose