Atomic Energy Organization of Iran Iran Nuclear Regulatory Authority (INRA) Ramsar the Radioactive Nature Presented by: Naser Rastkhah Head of INRA

Ramsar is a coastal city located in the north of Iran. And is well known for highest level of natural radiation among the worlds high levels of natural radiation areas (HLNRAs) such as : Kerala in India, Yangjiang in China, Guarapariin in Brazil, … ). Since 1959 this area is recognized as HLNRA and has been the subject of environmental radioactivity and epidemiological studies. Several national and international research teams visited the area and curried our research projects

An international conference on high levels of Natural Radiation was held in Ramsar jointly with WHO, UNEP and IAEA in 1990

The natural radiation in Ramsar is mainly due to the transfer of the dissolved radium in water to the ground surface through the hot springs. So the natural gamma dose rate is high in some areas. Outdoor gamma dose rate is dependent on the distribution of hot spring residues including Ra-226. In some places it is 22μGy/h at height of 1 m and 73μGy/h on the surface.

Hot Springs as a Source of Natural Radionuclide in Ramsar Region There are more than 9 hot springs with different concentrations of Ra-226 in Ramsar which people believe that they do well for rheumatism, neurotic and muscular pains, and skin diseases. Inhabitants who live in some houses in this area receive annual doses as high as 132 mSv. Cytogenetic studies show no significant differences between people living in the high background radiation areas comparing to those living in normal background areas.

Radon concentration at many homes is higher comparing to those homes constructed in normal areas. Location (Houses, Schools and Hotels) 222 Rn Concentration (kBq/m 3 ) Indoors3.1 Outdoors0.5

Some homes constructed with the stones containing high value of Ra-226 and having high level of Radon-222 concentration (3kBq/M3)

Since 1996, “High Natural Radiation Research Center” has been established in Ramsar to conduct research projects on high natural background radiation and epidemiological studies at the national and international level. Some laboratories such as radioecology, sample preparation as well as dosimetry have been established and equipped with the radiation detection equipments.

Passive Method: TL environmental Dosimeter (GR-200) Active Method: Proportional Gamma counter equipments in use for Gamma dose measurement

Detector: -Lexan Polycarbonate Electrochemical Etching Condition: -Solution: 15% KOH+40% C2H5OH+45% H2O -Field Strength : 32 kV/cm -Frequency: 2 kHz -Temperature: 25◦C Passive Radon Measurements (in Air) Radon Diffusion Chamber

Measurement of dissolved Radon in water AlphaGuard Pylon AB-5 Active Radon Measurements

A comprehensive action plan approved and scheduled by INRA in 2008 which consisted of 4 projects: a) Preparing the natural radioactivity map of Ramsar including measurement of gamma dose rate on the ground surface, radionuclide content of the soil, radium- 226 and Rn-222 content of the drinking water, Rn-222 concentration at homes following standard protocols. b) To determine precisely the exposure of people considering all pathways such as inhalation, ingestion and external exposure. c) To do a health surveillance programe for the people living in the area considering natural exposure. d) To provide guidelines and solutions to the inhabitants to reduce their exposure considering the social and economical impacts.

The area of Ramsar is about Km2. The central and most populated area (Red line) was selected for investigation and was divided to 2500 cells of dimension 50x50 m 2. The gamma dose rate was measured at 5 Cm and 100 Cm above the ground using scintilation survey meter. Maximum, minimum and average dose rate along with the georaphical specification of the cells registered for each cell.

Gamma dose rate measurement at 1 m above the ground

Project a) was ended by 2012 and Gamma Dose map of Ramsar at 1 meter above the ground was prepared. This project shall be extended to cover also the suburb of Ramsar 150 < nSv/h 150 < < < < < < < < < < < < < <15000 >15000

Project a) Gamma Dose map of Ramsar at 5 Cm above the ground was 150 < nSv/h 150 < < < < < < < < < < < < < <15000 >15000

INRA in Corporation with the Road, Housing and Urban Development Research Center approved the Regulation for the protection of buildings agaist the penetration of Radon gas to be implemented in high natural radiation areas

More budget and investment is needed to complete high natural background radiation research center of Ramsar. All researchers and interested research institutes and universities are highly welcomed for defining and performing common projects jointly with INRA as well as sponsorship to equip laboratories

Thank you for your attention