Review article Is it time to shed some light on the black box of health policies regarding the inhabitants of the high background radiation areas of Ramsar

*Corresponding author: Prof. Seyed Mohammad Javad Mortazavi, Department of Medical Physics and Medical Engineering, School of Medicine, and the Center for Research in Radiation Sciences (CRRS), Shiraz University of Medical Sciences, Shiraz, Iran. Fax: + 98 711 2349332 E-mail: mmortazavi@sums.ac.ir Although there are substantial experimental, epidemiological and clinical evidences that high doses of ionizing radiation cause cancer and other detrimental biological effects, the health effects of human exposure to chronic low dose radiation exposures are still poorly known. People in some areas around the world live in dwellings with radiation and radon levels as much as more than 200 times the global average. Inhabited areas with high levels of natural radiation are found in different areas around the world including Yangjiang, China; Kerala, India; Guarapari, Brazil and Ramsar, Iran. Ramsar in northern Iran is among the world’s well-known areas with highest levels of natural radiation. Annual exposure levels in areas with elevated levels of natural radiation in Ramsar are up to 260 mGy y-1 and average exposure rates are about 10 mGy y-1 for a population of about 2000 residents. Due to the local geology, which includes high levels of radium in rocks, soils, and groundwater, Ramsar residents are also exposed to high levels of alpha activity in the form of ingested radium and radium decay progeny as well as very high radon levels in their dwellings. Based on the findings obtained by studies on the health effect of high levels of natural radiation in Ramsar, as well as other high background radiation areas, no consistent detrimental effect has been detected so far. Further research is needed to clarify if the regulatory authorities should set limiting regulations to protect the inhabitants against such extraordinary elevated levels of natural radiation. Iran. J. Radiat. Res., 2012; 10 (3‐4): 111‐116