Occupational Respiratory Exposure Research Articles

Role of the occupational disease consultant in the multidisciplinary discussion of interstitial lung diseases.

Diffuse interstitial lung diseases (ILD) constitute a heterogeneous group of conditions with complex etiological diagnoses requiring a multidisciplinary approach. Much is still unknown about them, particularly their relationship with occupational exposures. The primary objective of this study was to investigate the distribution of occupational exposures according to type of ILD. The secondary objectives were to estimate the proportion of ILDs possibly related to occupational exposure and to evaluate the added value of the participation of an occupational disease consultant in ILD multidisciplinary discussions (MDD). From May to December 2020, all consecutive patients with ILD whose cases were reviewed during a MDD in a referral centre for ILD were prospectively offered a consultation with an occupational disease consultant. Of the 156 patients with ILD whose cases were reviewed in MDD during the study period, 141 patients attended an occupational exposure consultation. Occupational exposure was identified in 97 patients. Occupational exposure to asbestos was found in 12/31 (38.7%) patients with idiopathic pulmonary fibrosis (IPF) and in 9/18 (50.0%) patients with unclassifiable fibrosis. Occupational exposure to metal dust was found in 13/31 (41.9%) patients with IPFs and 10/18 (55.6%) patients with unclassifiable fibrosis. Silica exposure was found in 12/50 (24.0%) patients with autoimmune ILD. The link between occupational exposure and ILD was confirmed for 41 patients after the specialist occupational consultation. The occupational origin had not been considered (n = 9) or had been excluded or neglected (n = 4) by the MDD before the specialised consultation. A total of 24 (17%) patients were advised to apply for occupational disease compensation, including 22 (15.6%) following the consultation. In addition, a diagnosis different from the one proposed by the MDD was proposed for 18/141 (12.8%) patients. In our study, we found a high prevalence of occupational respiratory exposure with a potential causal link in patients with ILD. We suggest that a systematic specialised consultation in occupational medicine could be beneficial in the ILD diagnostic approach.

Causes of death among Federal Black Lung Benefits Program beneficiaries enrolled in Medicare, 1999-2016.

Coal miners with totally disabling pneumoconiosis are eligible for benefits through the Federal Black Lung Benefits Program (FBLP). We identify the causes of death among Medicare beneficiaries with a claim for which the FBLP was the primary payer and compare these causes of death to all deceased Medicare beneficiaries to better understand elevated death and disease among miners with occupational respiratory exposures. From 1999 to 2016 Medicare data, we extracted beneficiary and National Death Index data for 28,003 beneficiaries with an FBLP primary payer claim. We summarized the International Classification of Diseases, Clinical Modification 10th revision-coded underlying causes of death and entity-axis multiple causes of death for 22,242 deceased Medicare beneficiaries with an FBLP primary payer Medicare claim and compared their causes of death to the deceased Medicare beneficiary population. Among deceased FBLP beneficiaries, the three leading underlying causes of death were chronic obstructive pulmonary disease, unspecified (J44.9, 10.1%), atherosclerotic heart disease (I25.1, 9.3%), and coal workers' pneumoconiosis (CWP) (J60, 9.2%). All diseases of the respiratory system combined (J00-J99) were the underlying cause of death for 29.1% of all beneficiaries, with pneumoconioses (J60-J64) as the underlying cause for 11.0% of all beneficiaries. Coal miners enrolled in Medicare with an FBLP primary payer claim were more likely to have specific respiratory and cardiovascular diseases listed as a cause of death than deceased Medicare beneficiaries overall, and were also more likely to die from CWP or any pneumoconioses.

Does exposure to bentonite dust during tunnel hyperbaric interventions increase health risks for compressed air workers? A prospective qualitative and quantitative safety assessment

Introduction: The mining and tunneling industries are historically associated with hazardous exposures that result in significant occupational health concerns. Occupational respiratory exposures causing pneumoconiosis and silicosis are of great concern, silicosis being non-curable. This work demonstrates that compressed-air workers (CAWs) performing tunnel hyperbaric interventions (HIs) may be at risk for hazards related to bentonite exposure, increasing the likelihood of developing harmful illnesses including cancer. Bentonite dust inhalation may result in respiratory levels of silica exceeding acceptable industrial hygiene standards. Methods: A qualitative observational exposure assessment was conducted on CAWs while they were performing their HI duties. This was followed by quantitative data collection using personal and area air sample techniques. The results were analyzed and interpreted using standard industrial hygiene principles and guidelines from NIOSH and OSHA. Results: Our work suggests bentonite dust exposure may be an emerging particulate matter concern among CAWs in the tunneling industry. Aerosolized bentonite particles may have potential deleterious effects that include pneumoconiosis and silicosis. Silicosis can result in the development of pulmonary carcinoma. Conclusions: The modern tunneling industry and required hyperbaric interventional tasks represent a potential public health and occupational concern for CAWs. This paper introduces the modern tunneling industry and the duties of CAWs, the hazardous environment in which they perform their duties, and describes the risks and potential harmful health effects associated with these hazardous exposures.

Carbon monoxide emission rates from roasted whole bean and ground coffee

ABSTRACTCarbon monoxide (CO) emitted from roasted coffee is a potential occupational respiratory exposure hazard to workers within the coffee industry. The current study objective was to estimate CO emission factors from commercially available roasted whole bean and ground coffee measured in loose form, not packaged, and to assess the utility of CO monitoring in nonventilated storage spaces such as within coffee roasting and packaging facilities, transport vessels, and cafés. Determinants affecting CO emissions from coffee were investigated, including form (whole bean vs. ground), roast level (light, medium, medium-dark, dark), and age (time since the package was opened). CO emission factors were estimated for roasted coffee samples from a variety of manufacturers purchased from local grocery stores and online. Emission tests were performed on 36 brands of coffee, some with more than one sample per brand and with various roast levels. Decaying source equations or smoothing functions were fitted to the CO concentration measurements. Maximum observed emission factors at the peak of the predicted concentration curve were adjusted by the time required to reach the maximum CO concentration and reported as emission factors (EFbuildup). Ground coffee had a significantly increased EFbuildup (P < 0.0001) compared with whole bean. Roast level did not significantly affect emissions for whole bean (P = 0.72) but did for ground (P < 0.001) coffee. For ground coffee, medium-dark and dark roasts had significantly higher emissions than medium and light roasts. Worst-case emission factors from commercially available whole bean and ground coffee measured in loose form, not packaged, showed that roasted coffee can rapidly emit CO. CO concentrations should be monitored in storage spaces in service and manufacturing facilities as well as transport vessels to ensure exposures do not exceed occupational exposure limits. Storage spaces may need to be ventilated to control CO concentrations to safe levels.Implications: Emission rates of carbon monoxide (CO) from roasted coffee showed that unventilated or underventilated storage spaces should be monitored and ventilated, if necessary, to control CO concentrations to safe levels.

Occupational Respiratory Exposure to Platinum Group Metals: A Review and Recommendations.

Platinum group metals (PGMs) is a group of metals that include platinum, palladium, rhodium, ruthenium, iridium, and osmium. Occupational respiratory exposure to platinum has been reported since 1945, but studies investigating occupational exposure to palladium, rhodium, ruthenium, iridium, and osmium are scarce. This review provides a summation of the information available on the respiratory exposure to PGMs in various industrial settings, methods used to assess exposure, and the possible adverse health effects resulting from occupational exposure to PGMs. Of these effects, respiratory sensitization caused by soluble PGMs is of most importance. Metallic PGMs have not been shown to cause allergic reactions. This review reiterates that occupational respiratory exposure to PGMs is dependent on the type of industry where exposure takes place, the chemical form (soluble or insoluble) of the PGMs present in the workplace air, and the tasks performed by workers in the specific work areas. Sensitization to soluble platinum is associated with the degree of exposure to soluble platinum compounds, and the highest concentrations of soluble PGMs in workplace air have been reported for precious metals refineries where personal exposures frequently exceed the occupational exposure limit for soluble platinum (2 μg/m3). Additionally, this review emphasizes that personal exposure monitoring is preferred over area monitoring when assessing workers' exposure to PGMs. The legislation applicable to occupational exposure to PGMs is also discussed, and it is highlighted that the occupational exposure limit for soluble platinum has remained unchanged, in most countries, since 1970 and that too few countries have classified PGM compounds as respiratory or skin sensitizers. Finally, recommendations are made to ensure that future investigations are comparable in terms of the type of exposure monitoring (personal or area) conducted, the type of tasks included in the exposure monitoring program, and the format in which results are reported.

Respiratory Protection for Firefighters— Evaluation of CBRN Canisters for Use During Overhaul

In the United States, there are approximately 366,600 structural fires each year. After visible flames are extinguished, firefighters begin the overhaul stage of firefighting to smother remaining hot spots and initiate investigations. Typically during overhaul significant ambient concentrations of chemical contaminants remain. However, previous research suggests that the use of air purifying respirators (APR) fitted with chemical, biological, radiological, and nuclear (CBRN) canisters may reduce occupational respiratory exposures. This pilot study used large-scale prescribed burns of representative structural materials to perform simultaneous, side-by-side, filtering and service-life evaluations of commercially available CBRN filters. Three types of CBRN canisters and one cartridge were challenged in repetitive post live-fire overhaul exposure tests using a sampling manifold apparatus. At a flow rate of 80L/min, nine tests were conducted in the breathing zone for three different exposure durations (0–15 min, 0–30 min, and 0–60 min). Fifty different chemicals were identified for evaluation and results indicate that 21 of the 50 chemicals tested were in the air of the overhaul environment. Respirable particles and formaldehyde were consistently present above the American Conference of Governmental Industrial Hygienists (ACGIH®) recommended exposure level (REL) and threshold limit ceiling value (TLVc), respectively. Each filter effectively reduced concentrations for respirable particulates below the maximum recommended level. Formaldehyde was reduced, but not consistently filtered below the TLVc. These results were consistent across all exposure durations. This study indicates that, regardless of brand, CBRN filters provide protection from the vast majority of particle and gas-phase contaminants. However, due to formaldehyde breakthrough, CBRN filters do not provide complete protection during firefighter overhaul.

Lung function in fragrance industry employees

Production employees in the UK fragrance industry are exposed to large numbers of chemical substances and mixtures. There is a lack of published literature describing the effects of occupational respiratory exposure in this industry. To investigate whether occupational respiratory exposure to chemicals in the UK fragrance industry is linked to a statistically significant change in lung function as measured using spirometry. A multi-site cross-sectional study in which five UK companies took part, comprising an exposed group (fragrance production and associated functions) and a control group (non-exposed industry employees, e.g. office staff). Spirometric measurements (forced expiratory volume in 1 second, forced vital capacity and peak expiratory flow) were taken pre- and post-shift. Participants provided information on potential confounding factors (smoking, history of respiratory problems and body mass index). Post-shift measurements were compared between groups, using analysis of covariance to adjust for the baseline pre-shift measurements. A total of 112 subjects participated: 60 in the exposed group and 52 in control group (response rate 33 and 24%, respectively). Adjusted mean differences in post-shift spirometric measurements between exposed and control groups were not statistically significant. No significant effects were observed on the spirometric performance of the study population. This work is the first step in a novel area of research, and the industry would benefit from further such research.

Occupational History Quality in Patients With Newly Documented, Clinician-Diagnosed Chronic Bronchitis

Approximately 15% of cases of COPD, including chronic bronchitis, is attributable to occupational exposures. An occupational history is essential to identify exposures responsible for work-related chronic bronchitis. We conducted a structured retrospective analysis of the medical records of veterans, 18 to 70 years of age, newly diagnosed with chronic bronchitis in order to achieve the following: (1) to assess the quality of documented occupational histories; and (2) to characterize the management of patients with a history of exposure to a potentially hazardous respiratory substance. We also analyzed occupational exposure data reported by patients on a structured questionnaire. Sixty patients were included in the final analysis. A total of 6,150 notes were reviewed. Occupational status was documented in the records of 54 patients (90%). A description of occupational duties was recorded in 32 records (53%), and work exposure data in 26 records (43%). Clinicians concluded that occupational exposures potentially contributed to chronic bronchitis in three patients (5%). A recommendation for exposure avoidance was documented for six patients (10%). On the questionnaire, most patients reported a history of occupational exposure to respirable substances and symptoms of cough and/or shortness of breath. Details about job duties and occupational respiratory exposures were documented in the records of approximately half of patients with newly diagnosed chronic bronchitis. Patient self-reports of occupational exposures and respiratory symptoms were common. A determination that occupational exposures contributed to chronic bronchitis was rare. Few patients were counseled to take measures to avoid occupational exposures. Work-related chronic bronchitis may be incompletely assessed and undermanaged by clinicians.

Mapping the health and environmental situation in informal zones in Aleppo, Syria: report from the Aleppo household survey

Despite large communities living in informal zones around major cities in Syria, there is currently no information on the health and environmental situations in these areas. From May to August 2004, the Syrian Center for Tobacco Studies (SCTS) conducted the first household survey aiming to provide a baseline map of main health problems and exposures affecting these communities in Aleppo, the second largest city in Syria (2,500,000 inhabitants). Information on 1,021 participants randomly selected using stratified cluster sampling were available (46% males, mean age 34+/-11.7, age range 18-65 years, response rate 86%), including self-reported health/disability, exposures, and saliva cotinine measurement. Some positive findings include better than expected access to electricity, piped water, city sewage, and the use of propane for cooking. Particular areas of concern include high fertility rates, overcrowded housing conditions, and gender inequality in education and work. Household features likely to reflect negatively on residents' health include the use of diesel chimneys for heating and lack of smoking restrictions. Overall, residents of informal zones suffer from substantial physical and mental health problems and are exposed to high levels of indoor air pollution. All seem to affect women and the elderly disproportionately, while men are more affected by smoking, occupational respiratory exposures, and injuries. Both infectious and non-infectious respiratory outcomes were very common among study participants. Chronic and degenerative disease, including CVD and joint problems, were a source of substantial morbidity among the studied communities. This study highlights major health and environmental specificities of marginalized populations living in Aleppo, where women seem to bear a disproportionate burden of poor health and disability. Smoking and exposure to tobacco smoke seem among the major exposures facing these populations.

Sarcoidosis: impact of other illnesses on the presentation and management of multi-organ disease.

Sarcoidosis remains a fascinating illness that almost always affects the respiratory tract but often involves many other organs as well. Although many patients seem to have only an intrathoracic illness, with perhaps one other site or organ involved, others can experience a severe multi-organ disease. The inciting stimulus, even if unknown, can elicit an immunologic host response-the non-caseating granuloma-in almost every organ. It is intriguing that this stimulus can be so widespread throughout the body, while the biology of the disease can be so variable. Many series of patients with sarcoidosis have reported the multiple organs involved and the clinical presentation. Our series of 67 patients (40 female, 27 male, mean age 38.7 years +/- 13.2 (SD) at time of diagnosis) generally mirrors the clinical pattern found in five comparison series that span the past 60 years. However, more emphasis is given in this series to associated medical conditions that can complicate the presentation of sarcoidosis, as well as to co-morbid illnesses that must be managed in addition to the patient's sarcoidosis. Although most patients had intrathoracic sarcoidosis diagnosed at initial evaluation (40%), many had other organs or bodily sites involved in addition (or subsequently) as the illness evolved. Confounding the initial patient evaluation were two factors: (1) the presence of an occupational respiratory exposure(s) (n = 25 or 37% of patients); (2) a previously diagnosed malignancy (n = 6 or 9%) that heightened the possibility of a primary malignancy presenting in the chest, or the reactivation of a prior malignancy (breast, thyroid, and lymphoma) that could metastasize to the lung. Symptoms present when a patient's diagnosis was established usually differentiated respiratory and/or abdominal organ involvement. Although respiratory symptoms could be absent (n = 18 or 27%) for many patients with incidental thoracic findings, most had typical ones, including exertional dyspnea. For patients with an abdominal presenting illness (n = 11 or 16%), nonspecific digestive and abdominal symptoms were experienced as well as arthralgias. Almost every patient had at least one important other illness that factored significantly into the management of their sarcoidosis. Older patients had more illnesses, such as cardiovascular illness, diabetes mellitus, neurologic problems, and functional gastrointestinal symptoms. Depression affected all ages and was probably underrecognized; more emphasis on this illness is needed. Obesity was associated with disordered sleep syndromes, but not invariably so, as half the subjects had a good body habitus. Thus, many of the other illnesses experienced by sarcoidosis patients are common problems that middle-aged people develop. However, digestive and gastroenterological symptoms seemed disproportionately frequent in this series. This is a component of multi-organ sarcoidosis that has not received extensive coverage in the literature. Approximately one-third of sarcoidosis patients had one of two very common problems-gastroesophageal reflux or irritable bowel syndrome. But these are common problems, and it is thus necessary to separate these symptoms from those associated with abdominal visceral involvement of sarcoidosis. Although liver and/or splenic involvement with sarcoidosis do not cause organ dysfunction or insufficiency, they can contribute to abdominal symptoms. Finally, it remains of interest whether inflammatory bowel disease-Crohn's disease in particular-is another organ manifestation of sarcoidosis, or is it unrelated?

Trichloroethylene Cancer Risk: Simplified Calculation of PBPK-Based MCLs for Cytotoxic End Points

Cancer risk assessments for trichloroethylene (TCE) based on linear extrapolation from bioassay results are questionable in light of new data on TCE's likely mechanism of action involving induced cytotoxicity, for which a threshold-type dose–response model may be more appropriate. Previous studies have shown that if a genotoxic mechanism for TCE is assumed, algebraic methods can considerably simplify the use of physiologically based pharmacokinetic (PBPK) models to estimate virtually safe environmental concentrations for humans based on rodent cancer-bioassay data. We show here how such methods can be extended to the case in which TCE is assumed to induce cancer via cytotoxicity, to estimate environmentally safe concentrations based on rodent toxicity data. These methods can be substituted for the numerical methods typically used to calculate PBPK-effective doses when these are defined as peak concentrations. We selected liver and kidney as plausible target tissues, based on an analysis of rodent TCE-bioassay data and on a review of related data bearing on mechanism. Tumor patterns in rodent bioassays are shown to be consistent with our estimates of PBPK-based, effective cytotoxic doses to mice and rats used in these studies. When used with a margin of exposure of 1000, our method yielded maximum concentration levels for TCE of 16 ppb (87 μg/m3) for TCE in air respired 24 hr/day, 700 ppb (3.8 mg/m3) for TCE in air respired for relatively brief daily periods (e.g., 0.5 hr while showering/bathing), and 210 μg/liter for TCE in drinking water assuming a daily 2-liter ingestion. Cytotoxic effective doses were also estimated for occupational respiratory exposures. These estimates indicate that the current OSHA permissible exposure limit for TCE would produce metabolite concentrations that exceed anacuteno observed adverse effect level for hepatotoxicity in mice. On this basis, the OSHA TCE limit is not expected to be protective.

Airborne dust antigen exposure and specific IgG response in the potato processing industry

High prevalences of work-related respiratory symptoms in relation to organic dust exposure have been reported in the potato processing industry, but the responsible effect mechanisms are not known. To study the possible role of a type III allergy in aetiology. Specific immunoglobulin G (IgG) and IgG4 subclass antibodies against occupational airborne antigens were determined in sera from 131 potato processing workers and 36 non-exposed controls. Personal exposure to airborne antigens was measured, and a preliminary biochemical characterization was carried out. Specific IgG was detectable in almost all sera, but levels were significantly (P < 0.01) higher in potato processing workers compared with controls. Specific IgG4 was detectable in half of the workers' sera, but in none of the control sera. The antigens involved appeared to be heat-labile potato proteins. Antibody levels increased during the processing campaign in most workers, and this increase was dependent on the level of antigen exposure. Both the difference in IgG titres between the occupationally exposed group and the non-exposed group, and the exposure-related increase in specific IgG titres seemed to be mainly due to specific antibodies of the IgG4 subclass. Specific antibodies showed a non-significant tendency to lower levels in workers with work-related respiratory symptoms. Occupational respiratory exposure in the potato processing industry leads to a strong humoral immune response, most pronounced for IgG4 subclass antibodies. Type III allergy is, however, unlikely to play a predominant role in the aetiology of respiratory effects.

Changes in Forced Expiratory Volume in One Second and Peak Expiratory Flow Rate across a Work Shift among Unexposed Blue Collar Workers

Pre- and postshift spirometry was obtained on 1,113 blue collar workers employed at 35 work sites judged to have no hazardous occupational respiratory exposures on the basis of inspection visits and environmental sampling. In addition to spirometry, a standardized questionnaire was administered by trained personnel. A study population of 944 remained after exclusion of workers for incomplete demographic data and/or spirometry with poor within-session reproducibility, i.e., greater than or equal to 10% variability in the two largest values of either FVC and/or FEV1. Overall mean values of changes across the work shift in FEV1 and peak expiratory flow rate (PEFR) were -0.8% (-0.04 L) and +2.1% (+0.13 L/s), respectively. Standard deviations for these across-shift changes were 5.8% (0.19 L) and 13.2% (1.19 L/s) for FEV1 and PEFR, respectively. In univariate analyses, mean values of across-shift changes were not statistically related to age, race, sex, smoking status, work shift, or FEV1/FVC ratio. However, variability (i.e., standard deviation) of across-shift changes were significantly related to some of these factors. These observations provide a basis for interpreting results of occupational respiratory morbidity surveys involving measurement of changes in FEV1 and/or PEFR across a work shift.