[Mortality in nuclear workers of the French electricity company: period 1968-2003]. / Cohorte des travailleurs du nucléaire à Electricité de France: mortalité des agents statutaires sur la période 1968-2003.

BACKGROUND: We conducted a mortality study on a cohort of French nuclear workers employed at Electricité de France (EDF). A first cancer mortality analysis had covered the period 1968-1994. This paper presents results from a mortality analysis including nine additional years of follow-up to cover workers employed from 1968 to 2003. METHODS: The cohort includes 22393 workers, 97% of whom are males. Employment data were updated using the EDF personnel file. Vital status was ascertained using the French National Registry of Population, and further completed using EDF personnel and pension files. Causes of death were obtained from the National registry of causes of death. Standardised Mortality Ratios (SMR) were computed using national rates as references. Variations of all causes and all cancers SMRs were studied according to demographic and occupational characteristics. RESULTS: At the study end point (31/12/2003), 74% of workers are still in active employment. Only 0.3% of workers are lost to follow-up. The median duration of follow-up is 20 years. Causes are ascertained for 96% of deaths. The total number of deaths is 874, 307 of which are cancer deaths. SMRs for all causes and cancers show a significant deficit compared to the French national mortality. No significant excess was observed for any of the cancer sites studied. Non-significant excesses are observed for pancreatic, pleural, kidney and brain cancer. Significant variations of all causes SMRs according to age at study entry and attained age are observed. Significant variations of all causes and all cancers SMRs according to diploma at employment are observed, with a reduced SMR for a higher level of diploma. CONCLUSION: There is a significant deficit of mortality compared to the general population, reflecting a strong Healthy Worker Effect. Although nine years of follow-up were added, this cohort is made up of young workers, most of whom are still in active service. Regular updating of the follow up of this cohort is planned, aiming for an occupational health surveillance of workers occupationally exposed to ionizing radiation in France.

Intercomparison of passive dosimetry technology at EDF facilities in France.

Since the spring of 1999, new French radiation protection legislation has allowed the use of passive dosemeters, other than the silver emulsion film badge, for the measurement of H(p)(10). Faced with the eventual obsolescence of its dosimetry system, Electricité de France (EDF, the French electricity provider) initiated a comparative study of passive dosemeters, based on different technologies, that had received accreditation by national laboratories and regulatory bodies, namely: TLD, RPL and OSL. An extended field study in nuclear power stations and medical X-ray departments has shown that all technologies provide compatible dosimetric estimates. It also showed that the selected dosemeters based on RPL and OSL technologies gave better results due to their energy responses and to a lower detection threshold compliant with the new regulation. A final suggestion to implement a new OSL based dosimetric system is made due to its overall performance and to its lower cost of implementation.

Control of the risk of exposure to alpha emitting radionuclides in French nuclear power plants: example of Cattenom.

Control of the risk of internal exposure of EDF PWR plant maintenance workers by alpha-emitting radioactive elements is based on identification and quantification of the contamination of the systems. In 2001, an experiment carried out at Cattenom Power Plant during a unit outage in the presence of a leaking fuel cladding, based on measurement of alpha-emitting radioactive elements, made it possible to determine a realistic particle resuspension coefficient. A resuspension coefficient of 10(-6) m(-1) was adopted for operational radiological protection. An appropriate monitoring system for workers was set in place in collaboration with the occupational medicine and radiological protection department. It was based on prior estimation of the level of alpha contamination, and confirmed by swipe measurements, atmospheric surveillance by monitors, and collective analysis by nose blow samples from workers selected on the basis of their workstations, as well as supplementary individual measurements (monitoring of faeces). This surveillance made it possible to validate an appropriate work area monitoring system.

French approach for the distribution of iodine tablets in the vicinity of nuclear power plants.

In the event of an accident, isotopes of iodine including 131I can be released into the atmosphere. In 1997, as a safety measure, the French government decided to begin the distribution of stable iodine tablets in advance, directly to those living in the vicinity of the nuclear power plants, to avoid having to do so in an emergency. The tablets were previously stored by Electricite de France (EDF), which held them at the disposal of the government authorities. This year, as the existing tablets pass their use--by date, EDF has begun redistributing stable iodine within a ten-kilometer radius around its nineteen nuclear sites. We review the effectiveness of this countermeasure as well as the nature and incidence of possible side effects while measuring the duration of its action under the conditions in which it was administered. A bibliographic study of the kinetics of iodine in the human body has enabled the indications and the means of use to be determined. The effectiveness of the preventive effect and the onset of thyroid dysfunction depends on both external and individual factors: uptake of iodine from food, functional condition of the thyroid, and age. In an individual with a healthy thyroid, taking 100 mg of stable iodine immediately before exposure to radioactive iodine reduces the dose to the thyroid by at least 95%. In cases of prolonged exposure, the reduction is smaller. Therefore, if exposure lasts for a number of days, consideration needs to be given to taking stable iodine again, to maintain maximum protection. In addition to the bibliographic study, this presentation covers the impact of making iodine available and the action taken to educate the public; the attitudes of populations concerned; and the reaction of the health professionals.

[Medical surveillance of nuclear industry workers]. / Surveillance médicale des travailleurs de l'industrie nucléaire.

With a view to providing help for occupational doctors supervising nuclear plant workers, this article explains what "recommendations" means for the law make. It is the advice and counselling provided to doctors in order to heighten their awareness of specific problems; it does not mean instructions or stipulations to be scrupulously executed. A team of EDF (National French Electricity Board) doctors proposes an interpretation of these recommendations showing that they can help doctors evaluate the ability of workers according to their age, their antecedents, and the job's requirements. Thus, doctors are given greater freedom in the selection, frequency and interpretation of complementary examinations. Finally, the article develops the administrative aspect (filing, dosimetry) of worker supervision, and its connection with medical supervision.

[Biological and clinical prevalence of pollinosis caused by ragweeds of the upper valley of the Rhône corridor]. / Prévalence biologique et clinique de la pollinose due aux ambroisies dans la vallée supérieure du couloir rhodanien.

An epidemiological study of ragweed allergy was conducted on 646 employees belonging to 6 factories located in the Rhone valley south of the city of Lyon. Information on seasonal evocative clinical symptoms was obtained through a self-administered questionnaire. Biological prevalence was assessed by measuring anti-ragweed IgE specific antibodies. Measurements were performed by immunoenzymatic assay (W1 Phadezym RAST from Pharmacia). 34 (5,4%) subjects had evocative symptoms whereas 37 (5,9%) had increased specific IgE. Persons with the highest IgE levels were symptomatic. Concordance between symptoms and biology was 35% (12/34). Results indicate that sensitization level varies according to the location of the factory and people's residence, the risk to become allergic being of 10% in the most exposed population. This data emphasize the need to promote anti-ragweed eradication policy.