[Assessment of radon-induced health risk for occupants of a house built on uranium ore residue]. / Évaluation des risques sanitaires induits par le radon pour les occupants d'une maison construite sur des résidus de minerais d'uranium.

BACKGROUND: At the request of French public authorities, the Institute of Radiological Protection and Nuclear Safety has assessed the radiological situation of a house built on uranium ore residues in Haute-Vienne and the health risks induced from exposure to radon for all occupants. Classified as a lung carcinogen by the World Health Organization, radon is a proven cause of lung cancer in case of regular inhalation over a long period, and the risk increases with cumulative exposure. METHODS: Radon exposure was reconstructed for various standard profiles of house occupancy. A risk model derived from a European epidemiological study was used to calculate the lifetime probability of death from lung cancer according to these standard profiles. RESULTS: Risk assessment of the occupants of the house highlighted the following main findings. For a resident school child having been exposed to radon from birth to the age of 7, the lifetime relative risk (LRR) was estimated at 5. For last adult and young adult residents having lived more than 10years in the house, the probability of death from lung cancer was in the same order of magnitude as that of a regular cigarette smoker, with a LRR from 10 to 13 and a lifetime probability of death from lung cancer between 3 and 4%. If these individuals smoked regularly, in addition to being exposed to radon, this probability would be between 6 and 32% (supposing an additive or multiplicative interaction). CONCLUSION: For former occupants (non-smokers) having been exposed 10years during childhood, the LRR was two-fold lower. For children having been in day care in the house, the increased probability of death from lung cancer was low, with a LRR lower than 2. Supposing, as in adults, that the risk decreases beyond 30years after the end of radon exposure, the increase was almost zero for former occupants exposed during childhood and during day care, with a LRR close to 1.

NATIONAL DOSE REGISTER IN FRANCE WITHIN THE NATIONAL INFORMATION SYSTEM SISERI.

Over the past decade, France has developed an electronic dose register at national level called SISERI. Institute for Radiological Protection and Nuclear Safety is in charge of the management of this information system. Besides the main purpose of being a central register of any doses measured for the individual dosimetric monitoring of all exposed workers, SISERI has been developed so as to constitute a tool for occupational physicians and radiation protection officers allowing access in real-time to the results of the individual monitoring. The SISERI information system centralises, verifies and keeps the records of all personal dosimetric results of the 370 000 workers annually monitored in France. Moreover, since the publication of a new order in 2013, employers shall declare any new workers in SISERI before the beginning of their occupation and they shall upload data concerning in particular the activity field/sector and the occupation of each worker. The enforcement of this new order is going to enrich the individual dosimetric information stored in SISERI. Thus, it is expected that more precise and accurate statistics on occupational exposure to ionising radiation in France will be established in the next few years.

Risk of eye lens radiation exposure for members of the public.

In 2011, the International Commission on Radiological Protection (ICRP) reviewed its recommendation concerning the equivalent dose limit for the eye lens, lowering it to 20 mSv in a year, for occupational exposure in planned exposure situations. The ICRP's statement does not contain any explicit recommendations regarding the organ dose limit for the eye lens for public exposure. For the moment, no change is proposed. But, to be coherent in the overall approach, the current equivalent limit for the public might be lowered. A similar yardstick than in the former recommendation may be used, that is to say a reduction of 10 times lower than that for occupational exposure. In this context, additional data on potential scenarios for public exposure of the eye lens are necessary. This paper, mainly based on a literature study, aims to provide, as far as possible, an exhaustive list of the situations in which members of the public can be exposed at the level of the eye lens. Once these situations have been defined, some calculations, made to assess the associated doses to the eye lens, are presented. This literature study did not reveal any current situations where members of the public would receive significant radiation doses to the eye lens. Indeed, the situations in which the dose to the eye lens might reach around 1 mSv per year for the public are extremely rare.

Occupational external exposure to ionising radiation in France (2005-2011).

The Institute for Radiological Protection and Nuclear Safety (IRSN) produces the French annual report on occupational exposure to ionising radiation, collecting all national data and aggregating the results according to a unique activity classification expected to be shared by all involved in personal dosimetric monitoring (employers, external dosimetry services and IRSN). Nearly 344,000 monitored workers were counted in France in 2011, with a collective dose of 64.24 man.Sv. The average annual dose (as calculated over the number of measurably exposed workers) differed among the main activity fields: 0.54 mSv in medical and veterinary activities, 1.18 mSv in the nuclear field, 1.60 mSv in non-nuclear industry and 0.47 mSv in research activities. Because of improved knowledge about worker activities, the results for year 2011 are detailed per activity sectors in each field. Lasting limitations prevent from having complete and reliable worker activity information. Solutions are considered to reduce the inaccuracy in the annually published statistics. The evolution of occupational external exposure to ionising radiation from 2005 to 2011 in France is then presented for the main activity fields.

IRSN methodological guide to conducting workplace studies in compliance with French regulations.

Under French regulations governing radiation protection of workers, dosimetric workplace studies are mandatory. However, their practical implementation is not described. IRSN has developed a guide to help stakeholders in the radiological protection of workers conduct such studies. It proposes a general methodology applicable to most cases and 'workplace sheets', which apply this methodology to specific occupational settings. At present, two sheets are available: conventional radiology and interventional radiology.

French population exposure to radon, terrestrial gamma and cosmic rays.

In France, natural sources account for most of the population exposure to ionising radiation. This exposure varies widely with area. Radon and gamma-ray exposure data come from national measurement campaigns; cosmic doses were calculated from city altitude. These data were corrected for season of measurement, housing characteristics and population density to study their relationship with health indicators. The crude average of indoor radon concentrations was 89 Bq m(-3), and the average corrected for season and housing characteristics was 83 Bq m(-3) (range over districts: 19-297). Weighting by district population density yielded a national average of 63 Bq m(-3). Gamma-ray dose rates averaged 55 nSv h(-1) (23-96) indoors and 46 nSv h(-1) (25-85) outdoors; corrections did not change the means. Corrected cosmic annual doses averaged 0.28 mSv (0.27-0.38). These corrections estimated the radiation exposure of the French population more accurately and represented its distribution well, thereby allowing its study as a cofactor in ecological studies.

Numerical and experimental results of the operational neutron dosemeter 'Saphydose-N'.

Since 1993, the Institute for Radiological Protection and Nuclear Safety (IRSN) has lead, in association with Electricité de France (EDF), a R&D study of a neutron personal electronic dosemeter. This dosemeter, called 'Saphydose-N', is manufactured by the SAPHYMO company. This paper presents first the optimisation of some detector components using Monte Carlo calculations, and second the test of the manufactured Saphydose-N under radiation following the IEC 1323 standard's recommendations for active personal neutron dosemeters. The measurements with the manufactured dosemeter were performed on the one hand at PTB (Physikalisch-Technische Bundesanstalt) in mono-energetic neutron fields and, on the other hand at IRSN in neutron fields generated by a thermal facility (SIGMA), radionuclide ISO sources and a realistic spectrum (CANEL/T400). The manufactured dosemeter Saphydose-N was also tested during measurement campaigns of the European programme EVIDOS ('Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields') at different nuclear workplaces. The study showed that Saphydose-N complies with the recommendations of standard IEC 1323 and can be used at any workplace with no previous knowledge of the neutron field characteristics.

Performance of a cylindrical tissue-equivalent proportional counter for use in neutron monitoring.

Tissue-equivalent proportional counters (TEPC) allow the measurements of the absorbed dose and the ambient dose equivalent for neutron fields. A device based on this approach, called NAUSICAA((1,2)), has already been developed by IRSN to be used in high energy neutron fields for space applications. The response of this detector underestimates significantly the dose equivalent at low energies (several hundred keV) which represent the major component of neutron fields at workplaces in the nuclear industry. A counter with a similar geometry (cylindrical detector) and a lower gas pressure was studied in order to simulate a 1 microm biological site. In 2003, the performance of the device was further improved by adding a small amount of 3He to the tissue-equivalent gas (propane based) in order to increase the response for the lower energies of neutrons. Three amplification circuits were used to cover lineal energy range from 10(-1) to 10(4) keV microm(-1). Tests were performed in monoenergetic neutron and source fields. This paper presents the experimental results obtained with this change.

Determination of the physical and chemical properties, biokinetics, and dose coefficients of uranium compounds handled during nuclear fuel fabrication in France.

The introduction of new ICRP recommendations, especially the new Human Respiratory Tract Model (HRTM) in ICRP Publication 66 led us to focus on some specific parameters related to industrial uranium aerosols collected between 1990 and 1999 at French nuclear fuel fabrication facilities operated by COGEMA, FBFC, and the CEA. Among these parameters, the activity median aerodynamic diameter (AMAD), specific surface area (SSA), and parameters describing absorption to blood f(r), s(r) and s(s) defined in ICRP Publication 66 were identified as the most relevant influencing dose assessment. This study reviewed the data for 25 pure and impure uranium compounds. The average value of AMAD obtained was 5.7 microm (range 1.1-8.5 microm), which strongly supports the choice of 5 microm as the default value of AMAD for occupational exposures. The SSA varied between 0.4 and 18.3 m2 g(-1). For most materials, values of the absorption parameters f(r), s(r), and s(s) derived from the in vitro experiments were generally consistent with those derived from the in vivo experiments. Using average values for each pure compound allowed us to classify UO2 and U3O8 as Type S, mixed oxides, UF4, UO3 and ADU as Type M, and UO4 as Type F based on the ICRP Publication 71 criteria. Dose coefficients were also calculated for each pure compound, and average values for each type of pure compound were compared with those derived using default values. Finally, the lung retention kinetics and urinary excretion rates for inhaled U03 were compared using material-specific and default absorption parameters, in order to give a practical example of the application of this study.

[Geo-pathologic considerations on the most frequent tumors in Quebec presented in 1984-1986 and 1989-1991]. / Considérations géo-pathologiques sur les tumeurs les plus fréquentes au Québec relevées en 1984-1986 et 1989-1991.

This study describes the geographical variations in the incidence of, and mortality due to, the most frequent cancers in Quebec. They are breast, colon and tracheal, bronchial, and lung cancers in women and prostate, colon and trachea, bronchial and lung cancers in men. Data for the periods 1984 to 1986 and 1989 to 1991 for the whole of the Quebec Community Health Department are reviewed. A direct method of standardization, with the world population as the reference population, was used to allow comparison of geographical units. The ranking correlation method was used to test correlations for the various cancer sites. There were significant coefficients between the two periods only for lung cancer for both sexes, for both incidence and mortality. The spatial autocorrelation method was used to determine the presence or absence of a geographical configuration from the estimated rates. Moran I values were positive and significant for the two periods for lung cancer associated mortality and for the incidence of breast cancer. This implicates local factors (probably associated with lifestyle). The results for the incidence of lung cancer among men and women were similar for the period 1989 to 1991. The advantages and limitations of the methods used and also the data available are considered.

[A geographic analysis of regional disparities in temporal accessibility of emergency services to traffic accident victims in Quebec]. / Une analyse géographique des disparités régionales de l'accessibilité temporelle des traumatisés de la route aux services d'urgence au Québec.

This study provides a geographic analysis of variation in temporal accessibility to emergency services by accident victims within regional municipalities in Quebec. The model employed takes account of various post-accident variables (supply and demand; the service organization) which existed in Quebec in 1987. The study population consisted of 8,989 accident victims who required ambulance service between June 1 and August 31, 1987. The study concludes that the time between the accident and the arrival of the victim at the hospital was longer than one hour (the "Golden Hour") in 25% of the regional municipalities in distant regions and in the areas close to Ontario and the United States. Emergency interventions took less than 40 minutes in suburbs to the North and South of Montreal Island. Forty-eight percent of the variance is linked to the presence and the type of emergency services with an ATLS professional available and 20% is linked with the variables of distance and time.

Study of 222Rn permeation through polymer membranes: application to continuous measurement of 222Rn in water.

Membranes that exclude water but are permeable to radon can extend the range of environments where many radon detection systems could operate. We have studied the permeation of 222Rn through polypropylene membranes separating air and water phases. The permeation coefficient and the activation energy were calculated for various conditions. Potential applications, such as in situ detection of radon in water, are discussed.

Geographical variations of motor-vehicle injuries in Quebec, 1983-1988.

Data furnished by the Régie de l'Assurance Automobile du Québec (RAAQ) were used to describe the geography of motor vehicle accidents in the province of Quebec for the period 1983-1988. These were also used to evaluate the risk factors associated with zones of high risk with regards to accidents for the 97 Municipalités Régionales de Comté (MRC). The results demonstrate that non-severe accidents are more frequent in the urban context. On the other hand, severe accidents are more frequent in the rural context. The Standard Morbidity Ratio (SMR) highlights those MRC's with the risk of severe or non-severe accidents, where risks are twice that of Quebec as a whole. The demographic characteristics (age, sex) of the driver and passengers and the place of the accident (region, density) were used in the model LOGIT to evaluate risk factors associated with high risk zones. Results of the model for those severely injured are different from those for non-severely injured people. This holds true for the location of accidents as well as for demographic characteristics. In both models, women and people over 65 years of age are low-risk groups for accidents. The authors indicate certain action to be undertaken in Quebec by the Government to improve this situation.

Obesity, hypertension, hyperuricemia and diabetes mellitus among the Cree and Inuit of northern Québec.

In the last thirty years, sociocultural and political changes have profoundly affected the way of life of the Cree and Inuit of Northern Québec. Their health status profile has also changed. This study presents the main results of a health survey performed among the Cree and Inuit in 1982-1984 by a multidisciplinary team. Obesity, arterial hypertension, hyperuricemia and diabetes mellitus while almost unknown in the past, have now been added to the list of Cree and Inuit health problems. Crees have the highest risk for obesity, hypertension and diabetes mellitus. Hyperuricemia for unknown reasons seems more prevalent among the Inuit. Our findings suggest that further in-depth studies of chronic conditions in these communities are needed.

Radon in dwellings: physical and health properties.

It is well established that in certain areas abnormally high concentrations of radon can find its way into buildings and that its radioactive decay products are potentially carcinogenic when inhaled. This article reviews the studies that have been made in attempts to ascertain how far this represents a real public health hazard.

Correlates of health-care use: Inuit and Cree of northern Quebec.

This case study of the use of health-care services in northern Quebec is the first of a series of reports dealing with the health status, risk factors and access to care of the two major aboriginal populations in this region, the Cree and the Inuit. The focus of the broader study is on the health status and risk factors in these native populations. This research, based on a survey conducted in 1983-84, describes the present health status and health-care system of the Cree and Inuit, then presents a path analysis model of their use of health services. The purpose of this approach is to provide health planners and care providers with useful information and to encourage the development of well-organized and reasonable health-care service delivery to these populations.

The other face of development: native population, health status and indicators of malnutrition--the case of the Cree and Inuit of northern Quebec.

The cultural setting of the isolated Cree Indian and Inuit communities is described and measures of their health examined. Questionnaires were employed to consider both epidemiological and socio-cultural facets and physical examination evaluated serological indicators of nutritional status. Changes of lifestyle toward store purchased food and a lessened reliance on hunting and fishing along with the non-native nature of the health services available seem to be leading to heart conditions, hypertension and diabetes all of which give cause for concern.

Survey of natural radiation in France.

Survey of natural radiation is conducted in France since 1981, with the assessment of the components resulting from external sources (ground and building materials) using thermoluminescent dosemeters. In addition, the internal exposure to Rn-222 and the potential alpha energy due to radon daughters, are estimated by passive track detectors in the first case and active dosemeters in the second one. This paper presents the French program methods and results with an analysis and discussion of the observed levels.