Do asbestos-related pleural plaques on HRCT scans cause restrictive impairment in the absence of pulmonary fibrosis?

BACKGROUND: It is uncertain whether isolated pleural plaques cause functional impairment. OBJECTIVE: To analyse the relationship between isolated pleural plaques confirmed by CT scanning and lung function in subjects with occupational exposure to asbestos. METHODS: The study population consisted of 2743 subjects presenting with no parenchymal interstitial abnormalities on the high-resolution CT (HRCT) scan. Asbestos exposure was evaluated by calculation of an individual cumulative exposure index (CEI). Each subject underwent pulmonary function tests (PFTs) and HRCT scanning. Variables were adjusted for age, smoking status, body mass index, CEI to asbestos and the centres in which the pulmonary function tests were conducted. RESULTS: All functional parameters studied were within normal limits for subjects presenting with isolated pleural plaques and for those presenting with no pleuropulmonary abnormalities. However, isolated parietal and/or diaphragmatic pleural plaques were associated with a significant decrease in total lung capacity (TLC) (98.1% predicted in subjects with pleural plaques vs. 101.2% in subjects free of plaques, p=0.0494), forced vital capacity (FVC) (96.6% vs. 100.4%, p<0.001) and forced expiratory volume in 1 s (FEV(1)) (97.9% vs. 101.9%, p=0.0032). In contrast, no significant relationship was observed between pleural plaques and FEV1/FVC ratio, forced expiratory flow at 25-75% FVC and residual volume. A significant correlation was found between the extent of pleural plaques and the reduction in FVC and TLC, whereas plaque thickness was not related to functional impairment. CONCLUSIONS: The results show a relationship between isolated parietal and/or diaphragmatic pleural plaques and a trend towards a restrictive pattern, although the observed decrease in FVC and TLC is unlikely to be of real clinical relevance for the majority of subjects in this series.

Does asbestos exposure cause airway obstruction, in the absence of confirmed asbestosis?

RATIONALE: Whether occupational exposure to asbestos causes airway obstruction remains controversial. OBJECTIVES: This study evaluated lung function in relation to cumulative exposure to asbestos in a large cohort of retired or unemployed workers exposed to asbestos. METHODS: The study population consisted of 3,660 volunteer subjects. An individual cumulative exposure index to asbestos was calculated for each subject, and information was obtained on smoking status. Pulmonary function tests were performed in all subjects; high-resolution chest computed tomography was also performed in 3,335 subjects. MEASUREMENTS AND MAIN RESULTS: Values of FEV(1)/FVC and FEF(25-75%) did not differ between five classes (quintiles) of cumulative exposure to asbestos, and no significant correlation was observed between cumulative exposure to asbestos and pulmonary function parameters, after adjustment for sex, tobacco consumption, emphysema, and body mass index. Furthermore, the proportion of abnormal pulmonary function tests did not differ between the five classes of cumulative exposure to asbestos. CONCLUSIONS: The results do not support a causal relationship between asbestos exposure alone and airway obstruction. However, the study sample may not be representative of all people occupationally exposed to asbestos, because a fraction of subjects with previously diagnosed asbestosis probably did not participate in this screening program.

Occupational exposure to polycyclic aromatic hydrocarbons influenced neither the frequency nor the spectrum of FGFR3 mutations in bladder urothelial carcinoma.

Occupational exposure to polycyclic aromatic hydrocarbons (PAH) is associated with an increased risk of urothelial carcinoma (UC). FGFR3 is found mutated in about 70% of Ta tumors, which represent the major group at diagnosis. The influence of PAH on FGFR3 mutations and whether it is related to the emergence or shaping of these mutations is not yet known. We investigated the influence of occupational PAH on the frequency and spectrum of FGFR3 mutations. We included on 170 primary urothelial tumors from five hospitals from France. Patients (median age, 64 yr) were interviewed to gather data on occupational exposure to PAH, revealing 104 non- and possibly PAH exposed patients, 66 probably and definitely exposed patients. Tumors were classified as follows: 75 pTa, 52 pT1, and 43 > or =pT2. Tumor grades were as follows: 6 low malignant potential neoplasms (LMPN) and 41 low-grade and 123 high-grade carcinomas. The SnaPshot method was used to screen for the following FGFR3 mutations: R248C, S249C, G372C, Y375C, A393E, K652E, K652Q, K652M, and K652T. Occupational PAH exposure was not associated with a particular stage or grade of tumors. Thirty-nine percent of the tumors harbored FGFR3 mutations. After adjustment for smoking, occupational exposure to PAH did not influence the frequency [OR, 1.10; 95% CI, 0.78-1.52], or spectrum of FGFR3 mutations. Occupational exposure to PAH influenced neither the frequency nor the spectrum of FGFR3 mutations and there was no direct relationship between these mutations and this occupational hazard.

A prospective study of the psychological effects of "person under train" incidents on drivers.

Previous studies have shown that person under train (PUT) accidents cause psychological distress to drivers during the first year following the incident. Our aims were to assess the psychological consequences of PUT accidents on drivers prospectively, and to identify risk factors for psychological effects. In this prospective, one-year, follow-up study, a consecutive series of PUT drivers (n=202) were compared with a group of matched control drivers (n=186). Psychological state was assessed 15 days, 3 months and 1 year after the event, using the GHQ-28 questionnaire and a standardised diagnostic interview (the v4.4 MINI). Fifteen days after the event, PUT drivers had significantly higher GHQ-28 scores (p<0.0001) and more acute stress disorder (p=0.008) than control drivers. No significant differences were found 3 months and 1 year after the accident. Significant explicative variables were the presence of acute and chronic psychosocial stressors (OR=3.30 and 3.68) and the availability of immediate help (OR=0.46). We thus confirm previous findings that train drivers who have experienced a PUT accident experience acute psychological disturbances. Our results also highlight the utility of the systematic prevention programme provided.

Methacholine bronchial responsiveness and variations in lung function among workers exposed to flour.

OBJECTIVES: Methacholine bronchial responsiveness and variations in the pulmonary function of workers exposed to wheat flour and a reference group were compared. METHODS: Each subject [140 men exposed to flour (bakers and pastry makers) and 77 controls] completed a standardized questionnaire. Bronchial responsiveness was quantified by measuring the slope between percentage decrements in forced expiratory volume in 1 second (FEV1) and cumulative methacholine dose. FEV1 and peak expiratory flow (PEF) were recorded four times a day for 15 days using a handheld electronic spirometer. The variability in the FEV1 and PEF readings was expressed as variation coefficients (100 x standard deviation/mean). RESULTS: The mean duration of exposure to flour was 14 (SD 9) years. Rhinitis was significantly more common in the exposed group than in the control group (30.7% versus 11.7%, P = 0.001). The mean FEV1 and PEF did not significantly differ between the two groups. The slope of the dose-response to methacholine and the variation coefficients were lower among the unexposed nonsmokers than among the exposed workers and smokers. The differences were significant for the exposed smokers. The two variation coefficients correlated with each other (r = 0.82) but not with the slope of the methacholine challenge. Conclusions Occupational exposure to flour and smoking increase bronchial responsiveness, as measured by the slope of the dose-response to methacholine and the variation coefficients of airflow. However, methacholine bronchial responsiveness and the variability of lung function do not measure exactly the same aspect of airway behavior.

[Occupational exposure and bladder cancer]. / Cancers de la vessie d'origine professionnelle.

There is an important gap between the number of bladder cancer cases--over a 1000 per year--that are imputable, by epidemiologists'estimations, to occupational factors and the small number--fewer than 20--compensated as occupational diseases. This can be explained by the latency of the disease and by the fact that the chemicals mainly responsible for bladder cancer--aromatic amines compounds and, to a lesser extent, polycyclic aromatic hydrocarbons--are very complex and disseminated in a large variety of industrial settings. Besides the sectors historically known as involving this occupational risk--the dye and the rubber industries--new branches have been identified as hazardous: some sectors of plastic materials or aluminium industries, of laboratory research, the industrial gas production from coke ovens, foundries... The European policy for the prevention of occupational cancers has applied for over 10 years to carcinogenic aromatic amines. Screening for the early detection of vesical lesions is legally prescribed in France for workers that are or have been exposed to chemicals or processes potentially carcinogenic for the bladder.

Assessment of nasal fibroscopy to explore olfactory cleft.

OBJECTIVE: To assess whether flexible nasoendoscopy can be used to visualize all parts of the olfactory cleft (OC) without morbidity. STUDY DESIGN: Single-center, prospective, observational study. SETTING: French tertiary referral center. SUBJECTS AND METHODS: 100 consecutive patients were divided in 2 groups of 50. Group 1 underwent nasal fibroscopy without vasoconstriction or local anesthesia with an endosheath- protected endoscope. Group 2 was examined by a fiberscope without an endosheath after application of naphazoline Xylocaine. Each OC was divided in 16 items recorded as visualized or not. Four scores were compared between both groups: out of 16 (1 side), out of 32 (both sides), out of 12 concerning only the narrowest and highest bilateral spaces, and out of 4 to divide these specific areas in anterior, middle, and posterior parts. Length of procedure, pain, epistaxis, blood mark on the endosheath, sneezing, rhinorrhea, and causes of failure were recorded. RESULTS: There was no significant difference between both groups concerning score out of 16 or 32. The visibility of the narrower and higher spaces was better in group 2: scores out of 12 were significantly different between the groups (P = .025), as were scores out of 4 for the anterior and middle parts of the OC (P = .02 and .01 respectively). Morbidity was low without differences between the groups. Deviated nasal septum was the only cause of failure and increased the patients' pain during the examination (P = .045). CONCLUSION: Nasal fibroscopy could be used to explore the different portions of the OC efficiently and with low morbidity.

Occupational exposures and haematological malignancies: overview on human recent data.

OBJECTIVE: Occupational causes of haematological malignancies are relatively uncommon, under-studied and under-identified. They are also often unrecognized by clinicians. This review summarizes the principal epidemiologic studies on this topic. METHODS: We analyzed the recent relevant human data found in the Medline, the Pascal and the BDSP databases. RESULTS: Benzene and ionizing radiation are the only agents conclusively demonstrated to be carcinogenic to the haematopoietic system. In particular, both exposures are strongly associated with acute myeloid leukaemia. Low doses of both may also be related to myeloid malignancies. Infectious agents and pesticides are also thought to induce lymphoproliferative cancers. Some studies show an association between haematological malignancies and low-frequency electromagnetic fields and organic solvents. All of these suspected occupational causes must be confirmed by further studies. CONCLUSIONS: Better knowledge and understanding of occupational causes of haematological malignancies are necessary to improve their prevention and compensation.