Abstracts ASN Report 2019

׏ِ ב ِ ב xȒǼƺƬɖǼƏȸ ɀǣǕȇƏɎɖȸƺ ǣȇ ȸƏƳǣƏɎǣȒȇ ٮ ǣȇƳɖƬƺƳ ƬƏȇƬƺȸɀ It is currently impossible to distinguish a radiation-induced cancer from a cancer that is not radiation induced. The reason for this is that the molecular lesions caused by ionising radiation seem no different to those resulting from the normal cellular metabolism, with the involvement of free radicals –oxygenated ļŁ ŃĴŅŇļĶňĿĴŅ҂ ļŁ ĵłŇĻ ĶĴņĸņє ňŅŇĻĸŅŀłŅĸё Ňł ķĴŇĸё ŁĸļŇĻĸŅ anatomopathological examinations nor research for specific mutations have been able to distinguish a radiation-induced tumour from a sporadic tumour. It is known that in the first stages of carcinogenesis (process of cancer formation) a cell develops with a particular combination of DNA lesions that enables it to escape from the usual control of ĶĸĿĿňĿĴŅ ķļʼnļņļłŁё ĴŁķ ŇĻĴŇ ļŇ ŇĴľĸņ ĴĵłňŇ ŇĸŁ Ňł ӄӃӃׇ ĿĸņļłŁņ (mutations, breaks, etc.) at critical points to pass through these stages. All the agents capable of damaging cellular DNA (tobacco, alcohol, various chemical substances, ionising radiation, high temperature, other environmental factors, notably nutritional and free radicals of normal cellular metabolism, etc.) contribute to cellular ageing and to carcinogenesis. Consequently, in a multi-risk approach to carcinogenesis, can we still talk about radiation-induced cancers? Yes we can, given the quantity of epidemiological data which indicate that cancer frequency increases when the dose increases, with the other main risk factors taken into account. However, the radiation-induced event can also in certain cases be the only event responsible (radiation-induced cancers in children). Highlighting a radiological signature of cancers, that is to say the discovery of markers that could indicate whether a tumour has a radiation-induced component or not, would be of considerable benefit in the evaluation of the risks associated with exposure to ionising radiation, but has not been demonstrated to date. The multifactorial nature of carcinogenesis pleads in favour of a precautionary approach with regard to all the risk factors, since each one of them can contribute to DNA impairment. This is particularly important in persons displaying high individual radiosensitivity and for the most sensitive organs such as the breast and the bone marrow, and all the more so if the persons are young. Here, the principles of justification and optimisation are more than ever applicable (see chapter 2). ׫٫ ڲ The different sources of ionising radiation א ِ׏ zƏɎɖȸƏǼ ȸƏƳǣƏɎǣȒȇ Ł ŅĴŁĶĸё ĸŋŃłņňŅĸ Ňł ŇĻĸ ķļĹĹĸŅĸŁŇ ŇŌŃĸņ łĹ ŁĴŇňŅĴĿ ŅĴķļłĴĶŇļʼnļŇŌ (cosmic or terrestrial) represents on average about 65% of the total annual exposure. א ِ׏ِ׏ zƏɎɖȸƏǼ ɎƺȸȸƺɀɎȸǣƏǼ ȸƏƳǣƏɎǣȒȇ ٢ƺɴƬǼɖƳǣȇǕ ȸƏƳȒȇ٣ Natural radionuclides of terrestrial origin are present at various levels in all the compartments of our environment, including inside the human body. They lead to external exposure of the ŃłŃňĿĴŇļłŁ łŊļŁĺ Ňł ĺĴŀŀĴ ŅĴŌņ ĸŀļŇŇĸķ ĵŌ ŇĻĸ ňŅĴŁļňŀіӅӆӋׇĴŁķ ŇĻłŅļňŀіӅӆӅׇķĴňĺĻŇĸŅ ŃŅłķňĶŇņ ĴŁķ ĵŌ ŇĻĸ ŃłŇĴņņļňŀіӇӃׇŃŅĸņĸŁŇ ļŁ the soil, but also to internal exposure by inhalation of particles in suspension and by ingestion of foodstuffs or drinking water. The levels of natural radionuclides in the ground are extremely variable. Ļĸ ĸŋŇĸŅŁĴĿ ĸŋŃłņňŅĸ ķłņĸ ŅĴŇĸ ʼnĴĿňĸņ ļŁ ŇĻĸ łŃĸŁ ĴļŅ ļŁ ŅĴŁĶĸё depending on the region, range from a few nSv/h (nanosieverts ŃĸŅ ĻłňŅҏ Ňł ӄӃӃׇŁ ʼnѼĻє The dose rate values inside residential premises are generally higher owing to the contribution of construction materials (about 20% higher on average). Based on assumptions covering the time individuals spend inside ĴŁķ łňŇņļķĸ ŅĸņļķĸŁŇļĴĿ ŃŅĸŀļņĸņ ҎӌӃՌ ĴŁķ ӄӃՌ ŅĸņŃĸĶŇļʼnĸĿŌҏё the average effective dose due to external exposure to gamma ŅĴķļĴŇļłŁ łĹ ŇĸŅŅĸņŇŅļĴĿ łŅļĺļŁ ļŁ ŅĴŁĶĸ ļņ ĸņŇļŀĴŇĸķ ĴŇ ĴĵłňŇ Ӄєӈ ŀ ʼn ŃĸŅׇŃĸŅņłŁ ŃĸŅ ŌĸĴŅє The doses due to internal exposure of natural origin vary according to the quantities of radionuclides of the uranium and thorium families incorporated through the food chain, which depend on each individual’s eating habits. According to Institute of Radiation Protection and Nuclear Safety (IRSN) in 2015, the average dose per individual would be about 0.32 mSv/year (millisieverts per ŌĸĴŅҏє Ļĸ ĴʼnĸŅĴĺĸ ĶłŁĶĸŁŇŅĴŇļłŁ łĹ ŃłŇĴņņļňŀіӇӃׇļŁ ŇĻĸ łŅĺĴŁļņŀ ŅĸŃŅĸņĸŁŇņ ĴĵłňŇ ӈӈׇ ńѼľĺ ҎĵĸĶńňĸŅĸĿņ ŃĸŅ ľļĿłĺŅĴŀҏ ĵłķŌ ŀĴņņё ŅĸņňĿŇļŁĺ ļŁ ĴŁ ĴʼnĸŅĴĺĸ ĸĹĹĸĶŇļʼnĸ ķłņĸ łĹ ĴĵłňŇ ӃєӄӋ ŀ ʼnѼŌĸĴŅє Waters intended for human consumption, in particular ground- water and mineral waters, become charged in natural radionuclides depending on the nature of the geological strata. The concentration łĹ ňŅĴŁļňŀ ĴŁķ ŇĻłŅļňŀ ķĴňĺĻŇĸŅņ ĴŁķ łĹ ŃłŇĴņņļňŀіӇӃׇʼnĴŅļĸņ according to the resource exploited, given the geological nature łĹ ŇĻĸ ĺŅłňŁķє łŅ ŊĴŇĸŅņ ķļņŃĿĴŌļŁĺ ĻļĺĻ ŅĴķļłĴĶŇļʼnļŇŌё ŇĻĸ annual effective dose resulting from daily consumption (two litres per inhabitant per day) may reach several tens or hundreds of ի ʼnׇҎŀļĶŅłņļĸʼnĸŅŇņҏє א ِ׏ِ « א ƏƳȒȇ Some geological areas have a high radon exhalation potential due to the geological characteristics of the ground (granitic bedrock, for example). The concentration measured inside homes also depends on the tightness of the building (foundations) and the ventilation of the rooms. So-called “domestic” exposure to radon (radon in dwellings) has been estimated by IRSN through measurement campaigns which were then followed by statistical analyses (see irsn.fr ) . The average ŅĴķłŁ ĴĶŇļʼnļŇŌ ʼnĴĿňĸ ŀĸĴņňŅĸķ ļŁ ŅĴŁĶĸ ļņ Ӊӆׇ ńѼŀ 3 , with about ĻĴĿĹ ŇĻĸ ŅĸņňĿŇņ ĵĸļŁĺ ĵĸĿłŊ ӈӃׇ ńѼŀ 3 ё ӌՌ Ĵĵłʼnĸ ӅӃӃׇ ńѼŀ 3 ׇĴŁķ ӅєӆՌ Ĵĵłʼnĸ ӇӃӃׇ ńѼŀ 3 . Ļĸņĸ ŀĸĴņňŅĸŀĸŁŇņ ĻĴʼnĸ ĴĿĿłŊĸķ ŇĻĸ ŅĸŁĶĻ département s to be classified according to the radon exhalation potential of the ĺŅłňŁķє Ł ӅӃӄӄё ŃňĵĿļņĻĸķ Ĵ ŀĴŃ łĹ ŅĴŁĶĸ ĶłŁņļķĸŅļŁĺ ŇĻĸ radon exhalation potential of the ground, based on data from the ŅĸŁĶĻ ĸłĿłĺļĶĴĿ ĴŁķ ļŁļŁĺ ĸņĸĴŅĶĻ ĹĹļĶĸє Ĵņĸķ łŁ ŇĻļņё Ĵ more fine-grained classification, by municipality, was published ŇĻŅłňĺĻ ŇĻĸ ļŁļņŇĸŅļĴĿ ŅķĸŅ łĹ Ӆӊׇ ňŁĸ ӅӃӄӋׇҎņĸĸ ņĸĴŅĶĻ ĸŁĺļŁĸ by municipality and mapping accessible on asn.fr and irsn.fr ) . Ultimately, the new obligation placed on radon detector analysis laboratories to communicate the dosimeter results to IRSN ņĻłňĿķ ĸŁĻĴŁĶĸ ľŁłŊĿĸķĺĸ łĹ ŅĴķłŁ ĸŋŃłņňŅĸ ļŁ ŅĴŁĶĸ Ҏņĸĸ ŇĻĸ ӆŅķׇ ĴŇļłŁĴĿ ĿĴŁ ӅӃӄӉіӅӃӄӌׇĹłŅ ĴķłŁ ļņľ ĴŁĴĺĸŀĸŁŇё ŃňĵĿļņĻĸķ ļŁ ĴŁňĴŅŌ ӅӃӄӊׇĴŁķ ĴĶĶĸņņļĵĿĸ łŁ asn.fr ). א ِ׏ِ ! ב ȒɀȅǣƬ ȸƏƳǣƏɎǣȒȇ The cosmic radiation from ionic and neutronic components is also accompanied by electromagnetic radiation. At sea level, the dose rate resulting from electromagnetic radiation is estimated ĴŇ ӆӅׇŁ ʼnѼĻ ĴŁķ ŇĻĴŇ ŅĸņňĿŇļŁĺ ĹŅłŀ ŇĻĸ ŁĸňŇŅłŁļĶ ĶłŀŃłŁĸŁŇ ĴŇ ӆєӉׇŁ ʼnѼĻє 102 ASN Report on the state of nuclear safety and radiation protection in France in 2019 ׎׏ ٲ NUCLEAR ACTIVITIES: IONISING RADIATION AND HEALTH AND ENVIRONMENTAL RISKS