[Use of a job-exposure matrix for the screening of occupational exposure to asbestos]

[Screening of occupational exposure to asbestos and silica by job-exposure matrix among patients with lung cancer and mesothelioma]

INTRODUCTION

In the context of underreporting of occupational diseases, the aim was to study the validity of silica and asbestos job-exposure matrices in screening occupational exposure in the field of thoracic oncology.

METHODS

Fifty patients hospitalized with primitive lung cancer or mesothelioma in a university hospital center in the Hauts-de-Seine department of France were included between November 2016 and September 2017. For each patient 1/the job history was collected, from which data was entered single-blindly into the job-exposure matrices by a resident in occupational medicine, 2/a questionnaire (Q-SPLF) was completed similarly, and 3/the patients also had a consultation with a chief resident in occupational medicine, considered the gold standard. The main outcome was the diagnostic performance of the matrices. The Q-SPLF diagnostic performance was also studied.

RESULTS

The asbestos and silica matrices had sensitivities of 100%, specificities of respectively 76.1% and 87.8%, the positive likelihood ratios were at 4.19 [2.5-6] and 8.17 [3.8-10], and the negative likelihood ratios were at 0. The Q-SPLF diagnostic performance was comparable to that of the matrices.

CONCLUSIONS

The matrices and the questionnaire have a great diagnostic performance which seems interesting for a use as a screening tool for occupational exposures. These results have yet to be confirmed by large-scale studies.

Modelling prevalence and incidence of fibrosis and pleural plaques in asbestos-exposed populations for screening and follow-up: a cross-sectional study

BACKGROUND

CT-Scan is currently under assessment for the screening of asbestos-related diseases. However, to date no consensus exists as to how to select high-risk asbestos-exposed populations suitable for such screening programs. The objective of this study is to select the most relevant exposure variables for the prediction of pleural plaques and asbestosis in order to guide clinicians in their use of CT-Scan.

METHODS

A screening program of non malignant asbestos-related diseases by CT-scan was conducted among asbestos-exposed volunteers in France. Precise assessments of asbestos exposure were obtained by occupational hygiene measurements and a job-exposure matrix. Several parameters were calculated (time since first exposure, duration, intensity and cumulative exposure to asbestos). Predictive parameters of prevalence and incidence were then estimated by standard logistic and a complementary log-log regression models.

RESULTS

1011 subjects were recruited in this screening program among them 474 (46.9%) presented with pleural plaques and 61 (6.0%) with interstitial changes compatible with asbestosis on CT-scan. Time since first exposure (p < 0.0001) and either cumulative or mean exposure (p < 0.0001) showed independent associations with both pleural plaques and asbestosis prevalence and pleural plaques incidence. Modelling incidence of pleural plaques showed a 0.8% to 2.4% yearly increase for a mean exposure of 1 f/ml.

CONCLUSION

Our findings confirmed the role played by time since first exposure and dose but not duration in asbestos-related diseases. We recommend to include these parameters in high-risk populations suitable for screening of these diseases. Short-periodicity of survey of pleural plaques by CT-Scan seemed not to be warranted.

Évaluation quantitative du risque de cancer du poumon et de mésothéliome pleural chez les mécaniciens de véhicules automobiles

BACKGROUND

A quantitative assessment of the risk of lung cancer and pleural mesothelioma among mechanics exposed to dust released from automobile asbestos-containing parts was performed.

METHODS

The population of automobile mechanics in France, according to profession and industrial sectors codes, was estimated from the data of the 1999 census. Risks were computed for a total male population of 242,360 automobile mechanics aged 16 to 60 years. Exposure to asbestos among these workers comes from maintenance tasks involving asbestos-containing parts produced before 1997 (date of the asbestos ban in France). Airborne asbestos concentration data available from the literature were highly variable. No data reporting the distribution of time spent for such tasks over a typical week of work were available. Therefore, different weekly exposure profiles were simulated, based on data from the 1994 SUMER survey. Risk models were those used for assessing asbestos health effects by all national and international agencies. Exposure scenarios mixed different levels of exposure, periods of time, proportions of exposed workers and dates of the "natural" disappearance of the automobile fleet built before asbestos was banned in brakes and other parts. The most realistic scenario hypothesizes that all automobile mechanics were exposed to asbestos, that the exposure levels ranged from 0.06 and 0.25 fibers/liter per week for the period before 1997, and between 0.01 and 0.06 fibers/liter per week afterwards until 2010.

RESULTS

According to this scenario, the number of lifelong cancer deaths (lung and pleura) induced by asbestos exposure in this population is estimated at 602 "unavoidable" cases, due to exposure experienced before 2003; 43 other cases will occur if asbestos is not removed from existing automobiles.