Study on the ambient gamma radiation level of Pondicherry coastal ecosystem, India

Ionizing radiation expose to human being from natural sources is continuing inescapable feature of life on earth. Measurement of ambient gamma radiation was carried out in many countries. Such investigations can be useful to assess the environment and such studies will serve as baseline data for the ecosystem. They help to ascertain possible changes in the environmental radioactivity due to natural disaster, industrial and other human activities such as nuclear power production. Pondicherry coast is one of the undisturbed natural coastal ecosystem of south east cost of India. Ambient gamma survey was made in the entire coast of 35 km by fixing seven sampling stations with an interval of 5 Km. Survey was made for a year from April 2010 to March 2011, by Scintillometer (SM141 E) one meter above the ground. The ambient gamma radiation ranged from 3.1 to 5.1 μR/h with a mean value of 23.27 μR/h. Gamma radiation values registered in the present study are far low compared to adjacent coast Gulf of Mannar 10-45 μR/h, Kerala coast, 100-3000 μR/h and world average of range of 28-120 μR/h. The annual effective dose in this region was found to be 2.4 μSv/yr. (author)