Screening for occupational diseases related to asbestos in France : which medical examination should be preferred ?
Is chest X-ray examination obsolete ? Whether the patient is an employee or a craftsman, active or retired, the examinationsto which he is submitted will not be the same, although the risk of developing a professional disease due to asbestos may be the same.
This is quite surprising , all the more so as there seems to be a specific examination which can be quite effective for post professional monitoring.
Asbestos was introduced massively in indutrialized countries at the end of World War I.
The use of asbestos wasn’t controlled in France until 1977, when standards of exposure to fibres were introduced.
Asbestos has been classified as carcinogen since 1976 and banned in France since 1997.
The professions concerned by exposure to asbestos have evolved over the decades.
While occupational diseases used to strike professionals in production in the 1960s, painters and jewelers are now primarily concerned.
The building sector has been the most widely exposed in the last years.
For employees or former employees of the “régime général” (general scheme) which are not working any more
These people (inactive, seeking employment, retired ), who have been exposed to asbestos in the past, benefit from a post professional supervision.
The monitoring protocol was defined by the “annexe II de l’arrêté du 28 février 1995 pris en application de l’article D. 461-25 du code de la Sécurité sociale.
It sets the standards of exposure and the examination modes during the postoccupational supervisionof the employees who were exposed to carcinogenic agents or processes.
The examinations to be carried out are a clinical examination, a lung X-ray and sometimes a pulmonary function test (such as spirometry ) every 2 years.
These check-ups are entirely covered by the Funds of social and sanitary action of the Social Security .
For an employee still in activity, who was exposed to asbestos in the past or currently
These people are submitted to a clinical examination every year, to a chest X-ray and a spirometry every two years, in the context of a “surveillance médicale renforcée” (heightened medical supervision)carried out by the occupational physician in accordance with the order of December 13th, 1996 on the implementation of Articles 13 and 32 of Decree No. 96-98 dated February 7th, 1996 on the protection of workers against the risks associated with inhaling asbestos dust.
These articles determine the recommendations and the technical instructions that ought to be followed by the occupational physicians who are in charge of the medical watch of the concerned employees.
Although the Decree No. 96-98 was repealed, these articles are still in motion until the order linked to Article R 4412-138 of the labour regulations fixing the technical instructions that the occupational physician has to follow in the context of asbestos reinforced medical watch is publicated.
According to article R 4624-20, the occupational physician is judge of the frequency and nature of the examinations that are included in the reinforced medical watch and, in practice, the physician usually sets the same frequency for the complementary examinations and the clinical one, i.e. every year.
The assumption of regulatory examinations for monitoring falls to the company which currently employs the concerned person.
These examinations are assumed by the employer even if the employee is not exposed to asbestos in his company
For the craftsmen
One retired craftsman out of 2 has been exposed to asbestos during at least 25 years.
All craftsmen having been exposed to asbestos are currently being identified so as to offer them an exposure assessment and a medical watch
Only recently retired craftsmen and specific regions are concerned for the moment – Aquitaine, Poitou-Charentes, Nord-Pas-de-Calais, Lower and Upper-Normandy, Picardy. The physician carries out a clinical examination and necessarily sends the craftsman who was exposed to asbestos to a radiologist who makes a chest scanner without injection, spiralled multisection (or even monosection).
The examinations are covered by the HRI
In case of anomaly, the crafstman is sent to the Fund of compensation for the victims of asbestos (FIVA) for compensation.
The “Société française de pneumologie de langue française” ( SPLF ; french-languageSociety of pneumology) issued its latest recommendations for the detection of asbestos-linked diseases in 2006 . SuRprisingly, according to the SPLF, ”the medical and public health interest of screening is still not proved Rright in view of the data currently available on pleural mesothelioma -(frequency, prognosis, therapeutics ) and on the performance (sensitivity, specificity ) of screening tools (chest imagings, biological markers ‘).
Therefore, regulations go against the current scientifical data and the current provisions must be held as a precautionary principle.
The SPLF suggests a CT chest scan from the age 50, under the postoccupational supervision of people previously exposed to asbestos.
The thoracoabdominal tomographyis known as a key examination in the diagnostic imaging of pleural mesothelioma.
Indeed, it enables to spot pleural thickening, the impact of fissures, which are suggestive signs of the disease.
For the detection of mesothelioma, front chest X-rays are not sensitive enough to spot a pleural effusion clearly, even in conditions of standardized reading –LIO codification.
It lacks sensitivity to diagnose discrete forms of pulmonary or pleural fibrosis. It only enables to diagnose severe forms. In its recommendations of 1999, the SPLF laid stress on the radiation of the scanner that was likely to encourage the development of mesothelioma.
But the spiral CT, now available, only delivers a very small amount of radiation compared to a conventional scanner.
- In the U.S., the scanner is not used in the first stage
Only a lung X-ray (anteriorslanted picture) and a spirometry are carried out on this occasion.
It is only after these procedures that a scanner can be achieved .
- In Canada, a number of studies were carried out and several screening methods were tested : chest X-rays, pulmonary function tests, gallium 27 absorption coupled with nuclear imaging, axial tomography and broncho-alveolar lavage.
Here are the conclusions of these various studies : diseases linked to asbestos are often detected too late and axial tomography is more sensitive to detect the disease .
Currently, on a regulatory level, screening for diseases linked to asbestos includes a chest X-ray and a pulmonary function test for employees, whereas the assessment put in place by the HRI for recently retired craftsmen includes a Spiral CT exclusively.
Screening among craftsmen therefore seems much more in tune with the current recommendations of the SPLF for the detection of mesothelioma, than that among employees;
Some occupational physicians who ensure the monitoring of employees are getting concerned of this gap between scientific knowledge on the one hand and texts in motion on the other hand.
While physicians are taken to court for their so-called passivity in cases related to asbestos, shouldn’t a Spiral CT be part of the screening regulatory examinations for mesothelioma ?
Couldn’t occupational physicians be blamed for not prescribing this examination whereas it is known as the best adapted screening examination ?
A doctor involved is likely to be condemned for not having fulfilled his obligation of means using the best techniques.
But it is far from simple, for the Spiral CT is not covered by the employer because it is not part of the planned regulatory examinations. Were the Spiral CT to become part of it, we can easily imagine the cost of such a decision compared to mere lung X-rays, given the number of employees who would regularly benefit from it. But should human lives be sacrified to economic principles ?
It is a matter of public health which should be solved as soon as possible by the publication of the decree indicating the technical instructions that the occupational physician has to follow during the “surveillance médicale renforcée”(heightened medical supervision) for asbestos.