In vitro assessment of the immunity of implantable cardioverter-defibrillators to magnetic fields of 50/60 Hz.

Public concern for the compatibility of electromagnetic (EM) sources with active implantable medical devices (AIMD) has prompted the development of new systems that can perform accurate exposure studies. EM field interference with active cardiac implants (e.g. implantable cardioverter-defibrillators (ICDs)) can be critical. This paper describes a magnetic field (MF) exposure system and the method developed for testing the immunity of ICD to continuous-wave MFs. The MFs were created by Helmholtz coils, housed in a Faraday cage. The coils were able to produce highly uniform MFs up to 4000 µT at 50 Hz and 3900 µT at 60 Hz, within the test space. Four ICDs were tested. No dysfunctions were found in the generated MFs. These results confirm that the tested ICDs were immune to low frequency MFs.

Implantable cardioverter defibrillator and 50-Hz electric and magnetic fields exposure in the workplace.

PURPOSE: The operation of implantable cardioverter defibrillators (ICD) can be disrupted by exposure to electromagnetic fields (EMF). In the workplace, some workers can be exposed to EMF higher than in daily life. We present an approach aimed at assessing fitness for work in this type of situation, based on in situ case studies in the absence of clinical and in vivo studies. METHODS: A risk assessment protocol was developed to measure the 50-Hz electric and magnetic fields in the various places where the worker is likely to be present. These measures are taken in the worker's presence, while monitoring the ICD operation. RESULTS: All cases of implanted ICD workers in EDF, the French electricity company (around 130,000 employees), and potentially exposed to high electric and/or magnetic fields, between 2004 and 2009 are presented. These three cases involved different work circumstances, with exposure to 50-Hz electric and/or magnetic fields. No interference of the ICD was observed. CONCLUSIONS: This information provides the basis for the occupational physician to make a decision about fitness for work. This procedure can be extended to other medical implants and to electromagnetic fields frequencies other than 50-Hz.

Methodology of a study on the French population exposure to 50 Hz magnetic fields.

The characterisation of population exposure to a 50-Hz magnetic field (MF) is important for assessing health effects of electromagnetic fields. With the aim of estimating and characterising the exposure of the French population to 50-Hz MFs, two representative samples of the population were made. A random selection method based on the distribution of households in different regions of France was used. The samples were carried out starting from a random polling of telephone numbers of households (listed, unlisted fixed phones and cell phones only). A total of 95,362 telephone numbers were dialed to have 2148 volunteers (1060 children and 1088 adults). They all agreed to carrying an EMDEX II meter, measuring and recording MFs, and to filling out a timetable for a 24-hour period. In this article, the methodology of the sample selection and the collection of all necessary information for the realisation of this study are presented.

Characterization of exposure to extremely low frequency magnetic fields using multidimensional analysis techniques.

Our lack of knowledge about the biological mechanisms of 50 Hz magnetic fields makes it hard to improve exposure assessment. To provide better information about these exposure measures, we use multidimensional analysis techniques to examine the relations between different exposure metrics for a group of subjects. We used a combination of a two stage Principal Component Analysis (PCA) followed by an ascending hierarchical classification (AHC) to identify a set of measures that would capture the characteristics of the total exposure. This analysis gives an indication of the aspects of the exposure that are important to capture to get a complete picture of the magnetic field environment. We calculated 44 metrics of exposure measures from 16 exposed EDF employees and 15 control subjects, containing approximately 20,000 recordings of magnetic field measurements, taken every 30 s for 7 days with an EMDEX II dosimeter. These metrics included parameters used routinely or occasionally and some that were new. To eliminate those that expressed the least variability and that were most highly correlated to one another, we began with an initial Principal Component Analysis (PCA). A second PCA of the remaining 12 metrics enabled us to identify from the foreground 82.7% of the variance: the first component (62.0%) was characterized by central tendency metrics, and the second (20.7%) by dispersion characteristics. We were able to use AHC to divide the entire sample (of individuals) into four groups according to the axes that emerged from the PCA. Finally, discriminant analysis tested the discriminant power of the variables in the exposed/control classification as well as those from the AHC classification. The first showed that two subjects had been incorrectly classified, while no classification error was observed in the second. This exploratory study underscores the need to improve exposure measures by using at least two dimensions: intensity and dispersion. It also indicates the usefulness of constructing a typology of magnetic field exposures.

[Five-year survival of Ile-de-France cancer patients diagnosed in 1994]. / Survie à cinq ans des patients ayant eu un diagnostic de cancer en 1994 en Ile-de-France.

BACKGROUND: This study aimed to estimate survival at 5 years by localization, sex and stage of the patients who presented a new cancer in 1994 in the Ile-de-France area. METHODS: A cohort study began in 1994 by an exhaustive collection of the incidental cancers notified in the Ile-de-France area at the health insurance (27,080 patients). A stratified random sample based on tumor localization was followed at 1 year, 3 years and 5 years. The analysis of the observed survival was carried out according to Kaplan-Meier method. Relative survival was calculated according to Ederer II method. RESULTS: The follow-up sample concerned 4,166 patients. For all cancers, relative survival at 5 years was 65% for the women and 51% for the men. Relative survival rate at 5 years was 82% for the women with a breast cancer (98% for the patients in stage I) and 66% for those with a cancer of the cervix. Relative survival at 5 years for colonic cancer was 67% for men and 54% for women. For lung cancer, the relative survival rate fell from 47% for patients in stage I to 5% for those in stage IV. CONCLUSION: Our study produces population-based survival data for a entire geographical area covering 20% of the French population. Survival improves with earlier diagnosis but depends also on quality of care and availability of care: access to medical care can be a favouring factor. While in terms of incidence the situation in the Ile-de-France area is close to the national situation, survival at 5 years for a set of tumors appears to be better in this area than the nationwide figures. Besides providing information useful to determine mortality and incidence, the health insurance data offer additional insight to cancer epidemiology and contribute to better knowledge of this disease.

[Effects of 50 to 60 Hz and of 20 to 50 kHz magnetic fields on the operation of implanted cardiac pacemakers]. / Effets des champs magnétiques de 50 et 60 Hz et de 20 à 50 kHz sur le fonctionnement des cardiostimulateurs implantés.

UNLABELLED: The effect of 50 Hz and 60 Hz (frequencies of current distribution) and 20 kHz to 50 kHz (frequencies of induction cooktop) magnetic interference on implanted pacemakers have been assessed with the present generation of device technology. Sixty patients implanted in 1998 and 1999 with dual chamber pacemakers from 9 different manufacturers were monitored with telemetry while passing through, and standing between a system of two coils. They generated a 50 Hz or a 60 Hz magnetic field at 50 microT. Then, patients used a cooktop at different power. The recordings were made with the standard setting of "medically correct" sensing parameters chosen for the patients. Then pacemakers were reprogrammed to the unipolar mode, with the highest atrial (A) and ventricular (V) sensitivity that did not induce muscular inhibition while moving. Between each exposure (50 Hz, 60 Hz or 20 kHz to 50 kHz), the pacemaker programmation was controlled. At the end of the tests, pacemakers will be reprogrammed with the standard setting. The medical observer being blind to the existence or not of the magnetic field. No pacemaker was influenced by the vicinity of the magnetic field at medically correct settings. At unipolar high sensitivity, no inhibition nor reprogramming was observed. Transient reversion to interference mode was observed in 6 cases, 3 transient acceleration due to atrial detection of the interference, and one T wave detection by the ventricular lead. All were observed with the 60 Hz, and only 3 with the 50 Hz magnetic field. One device (Biotronik) shifted out of its special program (hysteresis research) during the tests with the induction cooktop, but it maintained its standard program, and the event could not be repeated despite further testing. CONCLUSION: Actual pacemakers do not present any electromagnetic interference with 50 Hz and 60 Hz or induction cooktop frequency working. They are insensitive with medically correct settings. Unusual high sensitivity leads only to noise reversion mode, or transient ventricular tracking.

[The Hemoccult II test: results of 16 years of screening tests at the Tumor Prevention Service of the City of Paris]. / Le test Hémoccult II: résultats de 16 ans de pratique dans le Service de Prévention et Dépistage des Tumeurs de la Ville de Paris.

OBJECTIVE: Colorectal cancer is a major health problem causing high mortality and short survival after diagnosis. Both the cancer itself and its precancerous lesion, the adenomatous polyp, can provoke occult bleeding. Screening programs for cancer of the colon use the Hemocult II test to detect such occult bleeding. We report the results obtained after 16 years of screening with the Hemocult II at the Paris tumor prevention center. METHODS: Since 1980, an annual Hemocult II test has been proposed to all consulting patients over the age of 40 years. Tests were self-administrated and returned to the center by mail. After rehydration, the tests were read by center nurses. RESULTS: The test was well accepted by the patients (78-90%). Over 16 years, the test led to the diagnosis of 18 cases of cancer, two-third of which were in an early stage (Dukes A) as well as 84 adenomatous polyps including 25% with signs of moderate to severe dysplasia and one case of diffuse adenomatous polyposis. Test sensitivity was 60%, with a 97% specificity and an overall (cancer and precancerous lesions) positive predictive value of 28.3%. In light of published data on the adenoma-cancer relationship, it can be estimated that 6 cancers were avoided. CONCLUSION: Hemoccult II is an easy to perform low-cost test well accepted by patients. Its use in a screening program can detect early stage precancerous and cancerous lesions of the colon.

[Intraepithelial carcinoma and invasive carcinoma of the vulva, vagina and penis in Ile-de-france. Enquete PETRI on 423 cases]. / Carcinomes intraépithéliaux et carcinomes invasifs de la vulve, du vagin et du pénis en Ile-de-France. Enquête PETRI portant sur 423 cas.

OBJECTIVE: Precancerous and invasive carcinoma of the external genitalia and of the vagina are rare tumors and their incidence is not very well known in the Paris region. The objective of this study was to evaluate the frequency of precancerous and invasive lesions of the vulva, the vagina and the penis as well as their variation according to age. METHODS: A prospective study was conducted implicating private and public pathology laboratories in Paris and the seven departments around. Four hundred and twenty three genital biopsies have been analyzed: 160 from the vulva, 151 from the vagina and 112 from the penis. RESULTS: The mean age of the patients was 45 years. The highest frequency of genital biopsies was similar for the three anatomical sites and concerned patients of 25-34 years old. intraepithelial neoplasias represented 77p. 100 of the biopsies (32p. 100 of low grade and 45p. 100 of high grade), invasive squamous carcinoma and adenocarcinoma represented 21p. 100 and 2p. 100 of cases, respectively. The mean age of the patients with low grade vulvar intraepithelial neoplasia, low grade vaginal intraepithelial neoplasia and low grade penile intraepithelial were 34, 40 and 33 years old, respectively. An interval of three to seven years separates the mean age of low grade intraepithelial neoplasia from the mean age of high grade. High grade intraepithelial neoplasia present a peak of frequency in the same class of age for the three localizations (25-34 years) and the risk of developing a high grade intraepithelial neoplasia of the external genital was higher between 25 and 35 years and between 35-45 years of the vagina. The mean age of invasive vulvar carcinoma, vagina carcinoma and penile carcinoma was 62, 59 and 68 years old, respectively. CONCLUSIONS: The correlation between the development of intraepithelial neoplasia of the vulva and the penis supposes a common aetiologic factor in the majority of the cases. The diagnosis of a intraepithelial neoplasia implies a clinical, colposcopic and follow-up of the entire genital area.

[Lifetime probability of developing a melanoma in the Ile-de-France in 1994]. / Probabilités de développer un mélanome au cours de la vie, en Ile-de-France en 1994.

OBJECTIVES: The probability of developing a cancer during lifetime is a global indicator, understandable by patients. It permits to establish a hierarchy of risks. An example of this indicator is calculated for melanoma. MATERIAL AND METHODS: The Seidman's method is used, with results of melanoma incidence in the Paris region in 1994 (PETRI's study). RESULTS: The risk of developing a melanoma during lifetime is 0.6 p. 100 for men and 1 p. 100 for women. CONCLUSIONS: Discussion of the assumptions used shows that this risk is underestimated. Although, it is high enough to justify preventive actions.

Absenteeism and mortality of workers exposed to electromagnetic fields in the French Electricity Company.

The objective of this study was to describe the health status of electricity workers exposed to electromagnetic fields during their job. Two groups of exposed workers were studied from 1978 to 1993: the live line workers (n = 121) and the substation workers (n = 232.7) of the French Electricity Company (EDF). A control group was randomly selected from all the company non-management male employees; one control for each exposed subject was matched for the first year of employment. Absenteeism indices and mortality rates were computed and compared in the exposed and control groups. The absence rates were 1.98% in the substation workers and 2.5% in the control group (p < 0.001) and 2.7% in the live-line workers and 2.8% in the control group (NS). No effect of the length of exposure was found. However the medical causes of sickness absence were different: exposed employees had less psychiatric and respiratory diseases but more accidents at work than their control group. Relative risks of accidents at work were 1.2 95% confidence interval (CI) = 1.08-1.33[ for substation workers and 3.22 (CI = 1.78-5.88) for live line workers. EDF electromagnetic field exposed workers seemed not to be affected by any specific health problems except for an excess of accidents at work.

Prospective study of the incidence of melanoma in the Paris region in 1994. The PETRI Melanoma Group.

The aim of this study was to estimate the incidence of melanoma in the Paris region in 1994 and analyse the main clinical and histological characteristics of these lesions. It took the form of a prospective inquiry, mailed to public and private pathology laboratories, to count as accurately as possible the number of new cases diagnosed by pathologists in the region during the 1994 calendar year. In all, 1089 newly diagnosed Clark level I to V melanomas (excluding precancerous melanosis of Dubreuilh) were studied. Parameters recorded included age, sex, Clark level and Breslow's thickness. The incidence per 100,000 inhabitants was 9.93 for melanoma and 8.62 for invasive melanoma. The female to male ratio was 1.6. Clark level I or thin (< 0.75 mm) melanomas represented 64.8% of the lesions. At the time of diagnosis, the females were significantly younger than the males (P = 0.004). Breslow's thickness increased with age and was significantly lower in women (P = 0.00005), especially those between 40 and 49 years old. The incidence of melanoma in the Paris region in 1994 was close to that observed during the preceding 5 years in England, Scotland and the French department of Haut-Rhin. It was 2.32 times higher for males and 1.69 times higher for females than the rates estimated for France for the period 1978-1982.

[Precancerous and cancerous involvement of the uterine cervix. Results of a survey conducted by the "Genital Cancers" group of Ile-de-France, May 1990-May 1992, based on 8,805 biopsies]. / Pathologie précancéreuse et cancéreuse du col de l'utérus. Résultats d'une enquête conduite par le groupe "cancers génitaux" de PETRI, dans la région Ile-de-France, de mai 1990 à mai 1992, et portant sur 8,805 biopsies.

Results of a study conducted by the "cervix cancer group" of PETRI, in Ile-de-France, from May 1990 to May 1992, and based on 8,805 biopsy specimens. In the absence of Cancer Registry in the Ile de France, no reliable data on invasive and preinvasive neoplasia of the cervix are available concerning this area. The aim of this survey, performed between May 15th, 1990 and May 15th, 1992 in 62 laboratories of pathology under the aegis of the Petri Association (Prévention et épidémiologie des tumeurs en Ile-de-France), was to obtain a better knowledge of this pathology, in which one of the major risk factors is the infection of the cervical epithelium by specific types of human papillomavirus. Over the course of these two years, 8,805 biopsy specimens, taken from neoplastic lesions of the cervix, were analyzed. Intra epithelial neoplasia represented more than 90% of the registered lesions. The average age at the time of the diagnosis was 32.4 years for the cases of condyloma, 32.7 years for CIN I, 33.8 years for CIN II, 36.3 years for CIN III, 45.7 years for micro-infiltrative carcinoma and 50.8 years for infiltrative squamous cell carcinoma. The breakdown of the different histological types of lesions is presented for three characteristic age groups (20-25, 30-35, and 60-70 years old). Differences observed in the eight departments belonging to the Ile-de-France are discussed.

[Control of laser treatment of 58 cervical condylomas: cyto-colposcopic correlations at 3, 6 and 12 months]. / Contrôle du traitement laser de 58 condylomes cervicaux: corrélations cyto-colposcopiques à 3, 6 et 12 mois.

Cytologic and colposcopic findings 3, 6 and 12 months after laser treatment of cervical condyloma or intraepithelial neoplasia have been studied. Cytologic features of Papillomavirus infection were evidenced in 28 cases by cytology but only in 12 by colposcopy. The cytologic most frequent feature was parakeratosis without clear koilocytosis. One year after laser treatment, cytology and colposcopy showed features of papillomavirus infection in only seven cases. Thus, spontaneous regression of colposcopically detected lesions occurred in five cases. In 16 cases, the parakeratosis detected on the first smear seem to represent healing and tissue maturation more than the persistence of HPV infection.