BACKGROUND: Early studies during the COVID-19 pandemic suggested dental occupations were among the highest risk for exposure to SARs-CoV-2 because of multiple factors increasing exposure, including close proximity to unmasked patients and performance of aerosol-generating procedures. However, to date, few studies have investigated COVID-19 deaths in United States dental occupations, and compared COVID-19 deaths among healthcare occupations. METHODS: We analyzed 2020 mortality data collected by the National Center for Health Statistics' National Vital Statistics System. Multivariable logistic regression was used to generate odds ratios (ORs) and 95% confidence intervals for COVID-19 as the underlying cause of death in relation to occupation in working-age decedents (≤65 years), after adjusting for age, sex, race/ethnicity, education, and medical conditions associated with severe COVID-19. RESULTS: Dental occupations did not have significantly higher risk for COVID-19 death when compared to all other occupations combined. Among healthcare occupations with frequent, direct patient- or client interactions, LPNs and LVNs, and speech and language pathologists had significantly elevated adjusted ORs for COVID-19 death when compared to dentists, dental hygienists, or dental assistants. Similarly, nurse practitioners had significantly higher ORs for COVID-19 mortality than dentists or dental hygienists, and approached significance when compared to dental assistants. Conversely, massage therapists and other health diagnosing and treating practitioners had significantly lower adjusted ORs for COVID-19 death compared with dental occupations. CONCLUSION: Our study highlights potential differences in work-related transmission of SARs-CoV-2 and subsequent COVID-19 deaths in healthcare occupations, and furthers a previously limited understanding of COVID-19 deaths in healthcare occupations in 2020, before COVID-19 vaccine availability. Our results indicate that dental occupations were not among the highest, nor lowest risk, healthcare occupations for COVID-19 deaths in 2020, despite their known risks of direct exposure.

Recognition that an individual's job could impact their likelihood of contracting coronavirus disease 2019 created challenges for investigators who sought to better understand and prevent transmission of the severe acute respiratory syndrome coronavirus 2. Considerable research resources were devoted to separating the effects of occupational from non-occupational risk factors. This commentary highlights results from studies that adjusted for multiple non-occupational risk factors while estimating the effects of occupations and occupational risk factors. Methods used in these studies will prove useful in future infectious disease epidemics and pandemics, and could potentially enrich studies of other occupational infectious and non-infectious respiratory diseases as well.

BACKGROUND: Sporicidal products containing hydrogen peroxide (HP), peracetic acid (PAA), and acetic acid (AA) are used widely in multiple industries, including healthcare. Despite widespread use in healthcare, few studies have assessed associations between exposures to HP, PAA, and AA, and work-related symptoms in these settings. METHODS: In 2018, we performed a health and exposure assessment at a hospital where a sporicidal product consisting of HP, PAA, and AA, was used as the primary cleaner on hospital surfaces. We collected 56 personal and mobile air samples for HP, PAA, and AA on participants while they performed their regular cleaning duties; collected area samples for HP (n = 28), PAA (n = 28), and AA (n = 70) in multiple hospital locations where cleaning was performed; and administered a postshift survey to assess eye, skin, and upper and lower airway symptoms that occurred cross-shift or in the previous 4 weeks. RESULTS: Full-shift exposure levels for HP (range: <3-559 ppb), PAA (range: <0.2-8 ppb), and AA (range: <5-915 ppb) were all below US occupational exposure limits. We observed positive associations (p < 0.05) between shift, departmental average, and departmental 95th percentile exposures to HP, PAA, and AA vapors, and work-related acute (cross-shift) and chronic (previous 4 weeks) eye, upper airway, and lower airway symptoms after adjusting for age, gender, smoking status, use of other cleaning products containing sensitizers and irritants, allergic status, and stress. CONCLUSIONS: Our observations of work-related upper and lower airway symptoms among hospital workers exposed to vapors from a sporicidal product containing HP, PAA, and AA indicate a need for a combination of engineering, administrative, and PPE controls to reduce exposure. Additionally, alternative nonchemical disinfection technologies should be further investigated as a means to simultaneously reduce healthcare workers' exposure to disinfectants while also minimizing costly healthcare-acquired infections.

PURPOSE: The Keokuk County Rural Health Study (KCRHS) is a longitudinal population-based study conducted in rural Iowa. A prior analysis of enrollment data identified an association of airflow obstruction with occupational exposures only among cigarette smokers. The current study used spirometry data from all three rounds to investigate whether level of forced expiratory volume in one second (FEV(1)) and longitudinal change in FEV(1) were associated with occupational vapor-gas, dust, and fumes (VGDF) exposures, and whether these associations were modified by smoking. METHODS: This study sample comprised 1071 adult KCRHS participants with longitudinal data. A job-exposure matrix (JEM) was applied to participants' lifetime work histories to assign exposures to occupational VGDF. Mixed regression models of pre-bronchodilator FEV(1) (millimeters, ml) were fit to test for associations with occupational exposures while adjusting for potential confounders. RESULTS: Mineral dust had the most consistent association with change in FEV(1), including ever/never ( - 6.3 ml/year) and nearly every level of duration, intensity, and cumulative exposure. Because 92% of participants with mineral dust also had organic dust exposure, the results for mineral dust may be due to a combination of the two. An association of FEV(1) level with fumes was observed for high intensity ( - 91.4 ml) among all participants, and limited to cigarette smokers with results of  - 104.6 ml ever/never exposed,  - 170.3 ml high duration, and  - 172.4 ml high cumulative. CONCLUSION: The current findings suggest that mineral dust, possibly in combination with organic dust, and fumes exposure, especially among cigarette smokers, were risk factors for adverse FEV(1) results.

The articles published as part of the Frontiers in Public Health research topic, "Investigating exposures and respiratory health in coffee workers" present research findings that better characterize exposures to diacetyl and 2,3-pentanedione and inform our understanding of the health risks posed by these exposures. Although various research groups and organizations have conducted risk assessments to derive occupational exposure limits (OELs) for diacetyl, differences in the data used and assumptions made in these efforts have resulted in a wide range of recommended OELs designed to protect human health. The primary drivers of these differences include the decision to use data from human or animal studies in conducting a quantitative risk assessment, and the application of uncertainty factors (UF) to derive an OEL. This Perspectives paper will discuss the practical implications of these decisions, and present additional commentary on the potential role that the recent investigation of human exposures to relatively low concentrations of α-diketones, specifically diacetyl and 2,3-pentanedione, may play in supporting qualitative or quantitative human health risk assessments.

Workers in the coffee industry face a variety of inhalational hazards. These range from predominantly organic dust, endotoxin, and green and castor bean allergen exposures in the primary processing factories to dusts, gases, and vapors including α-diketones in coffee production facilities (1–5). Previously documented respiratory health effects include symptoms such as wheeze, cough, and dyspnea, bronchial hyperresponsiveness, reduced spirometric parameters, and chronic lung diseases including asthma and obliterative bronchiolitis (OB) (3, 5–10). Some of these studies are decades old, while some are notable for small size and limited exposure assessments. In this special issue of Frontiers in Public Health on “Investigating exposures and respiratory health in coffee workers”, a series of articles explores in detail the exposures, emissions, engineering controls, and health consequences across the contemporary coffee industry by describing studies of primary processing in 16 factories in two African countries and coffee production in 17 facilities in the United States.

Indoor dampness and mold are prevalent, and the exposure has been associated with various illnesses such as the exacerbation of existing asthma, asthma development, current asthma, ever-diagnosed asthma, bronchitis, respiratory infection, allergic rhinitis, dyspnea, wheezing, cough, upper respiratory symptoms, and eczema. However, assessing exposures or environments in damp and moldy buildings/rooms, especially by collecting and analyzing environmental samples for microbial agents, is complicated. Nonetheless, observational assessment (visual and olfactory inspection) has been demonstrated as an effective method for evaluating indoor dampness and mold. The National Institute for Occupational Safety and Health developed an observational assessment method called the Dampness and Mold Assessment Tool (DMAT). The DMAT uses a semi-quantitative approach to score the level of dampness and mold-related damage (mold odor, water damage/stains, visible mold, and wetness/dampness) by intensity or size for each of the room components (ceiling, walls, windows, floor, furnishings, ventilation system, pipes, and supplies and materials). Total or average room scores and factor-or component-specific scores can be calculated for data analysis. Because the DMAT uses a semi-quantitative scoring method, it better differentiates the level of damage compared to the binary (presence or absence of damage) approach. Thus, our DMAT provides useful information on identifying dampness and mold, tracking and comparing past and present damage by the scores, and prioritizing remediation to avoid potential adverse health effects in occupants. This protocol-type article describes the DMAT and demonstrates how to apply it to effectively manage indoor dampness and mold-related damage. © 2022 by the authors.

Coffee production workers are exposed to complex mixtures of gases, dust, and vapors, including the known respiratory toxins, diacetyl, and 2,3-pentanedione, which occur naturally during coffee roasting and are also present in flavorings used to flavor coffee. This study evaluated the associations of these two -diketones with lung function measures in coffee production workers. Workers completed questionnaires, and their lung function was assessed by spirometry and impulse oscillometry (IOS). Personal exposures to diacetyl, 2,3-pentanedione, and their sum (Sum(DA+PD)) were assigned to participants, and metrics of the highest 95th percentile (P95), cumulative, and average exposure were calculated. Linear and logistic regression models for continuous and binary/polytomous outcomes, respectively, were used to explore exposure-response relationships adjusting for age, body mass index, tenure, height, sex, smoking status, race, or allergic status. Decrements in percent predicted forced expiratory volume in 1 second (ppFEV(1)) and forced vital capacity (ppFVC) were associated with the highest-P95 exposures to 2,3-pentanedione and Sum(DA+PD). Among flavoring workers, larger decrements in ppFEV(1) and ppFVC were associated with highest-P95 exposures to diacetyl, 2,3-pentanedione, and Sum(DA+PD). Abnormal FEV(1), FVC, and restrictive spirometric patterns were associated with the highest-P95, cumulative, and average exposures for all -diketone metrics; some of these associations were also present among flavoring and non-flavoring workers. The combined category of small and peripheral airways plus small and large airways abnormalities on IOS had elevated odds for highest-P95 exposure to -diketones. These results may be affected by the small sample size, few cases of abnormal spirometry, and the healthy worker effect. Associations between lung function abnormalities and exposure to -diketones suggest it may be prudent to consider exposure controls in both flavoring and non-flavoring settings.

The assemblage of fungi including unicellular yeasts in schools is understudied. We conducted an environmental study to characterize fungal communities in classroom floor dust. We collected 500 samples from 50 elementary schools in Philadelphia, PA, and evaluated room dampness/mold conditions. Genomic DNA from dust was extracted for internal transcribed spacer 1 Illumina MiSeq sequencing to identify operational taxonomic units (OTUs) organized from DNA sequences. Differential abundance analyses were performed to examine significant differences in abundance among groups. We identified 724 genera from 1490 OTUs. The genus Epicoccum was not diverse but the most abundant (relative abundance = 18.9%). Fungi were less diverse but most dissimilar in composition in the most water-damaged classrooms compared to the least water-damaged, indicating differential effects of individual classroom water-damage on fungal compositions. We identified 62 yeast genera, representing 19.6% of DNA sequences. Cyberlindnera was the most abundant (6.1%), followed by Cryptococcus, Aureobasidium, Rhodotorula, and Candida. The average relative abundance of yeasts tended to increase with increasing dampness and mold score and was significantly (p-value = 0.048) higher in the most water-damaged classrooms (22.4%) than the least water-damaged classrooms (18.2%). Our study suggests the need for further research on the potential health effects associated with exposures to yeasts in schools.

BACKGROUND: The potential for work to be a risk factor for coronavirus disease 2019 (COVID-19) was recognized early in the pandemic based on the likelihood of work-related differences in exposures to COVID-19 in different occupations. Due to intense demands of the pandemic, implementation of recommendations to collect information on occupation in relation to COVID-19 has been uneven across the United States. The objective of this study was to investigate COVID-19 test positivity by occupation. METHODS: We analyzed data collected from September 8 to November 30, 2020, by the Delphi Group at Carnegie Mellon University USCOVID-19 Trends and Impact Survey, offered daily to a random sample of US-based Facebook users aged 18 years or older, who were invited via a banner in their news feed. Our focus was ever testing positive for COVID-19 in respondents working outside the home for pay in the past 4 weeks. RESULTS: The major occupational groups of"Production", "Building and grounds cleaning and maintenance,""Construction and extraction,""Healthcare support,"and "Food preparation and serving" had the five highest test positivity percentages (16.7%-14.4%). Highest detailed occupational categories (28.6%-19.1%) were "Massage therapist,""Food processing worker,""Bailiff, correctional officer, or jailer,""Funeral service worker,""First-line supervisor of production and operating workers,"and "Nursing assistant or psychiatric aide."Differences in test positivity by occupation remained after adjustment for age, gender, and pre-existing medical conditions. CONCLUSION: Information on differences in test positivity by occupation can aid targeting of messaging for vaccination and testing and mitigation strategies for the current and future respiratory infection epidemics and pandemics. These results, obtained before availability of COVID-19 vaccines, can form a basis for comparison to evaluate impacts of vaccination and subsequent emergence of viral variants.

Coffee production workers can be exposed to inhalational hazards including alpha-diketones such as diacetyl and 2,3-pentanedione. Exposure to diacetyl is associated with the development of occupational lung disease, including obliterative bronchiolitis, a rare and irreversible lung disease. We aimed to identify determinants contributing to task-based exposures to diacetyl and 2,3-pentanedione at 17 U.S. coffee production facilities. We collected 606 personal short-term task-based samples including roasting (n = 189), grinding (n = 74), packaging (n = 203), quality control (QC, n = 44), flavoring (n = 15), and miscellaneous production/caf tasks (n = 81), and analyzed for diacetyl and 2,3-pentanedione in accordance with the modified OSHA Method 1013/1016. We also collected instantaneous activity-based (n = 296) and source (n = 312) samples using evacuated canisters. Information on sample-level and process-level determinants relating to production scale, sources of alpha-diketones, and engineering controls was collected. Bayesian mixed-effect regression models accounting for censored data were fit for overall data (all tasks) and specific tasks. Notable determinants identified in univariate analyses were used to fit all plausible models in multiple regression analysis which were summarized using a Bayesian model averaging method. Grinding, flavoring, packaging, and production tasks with ground coffee were associated with the highest short-term and instantaneous-activity exposures for both analytes. Highest instantaneous-sources of diacetyl and 2,3-pentanedione included ground coffee, flavored coffee, liquid flavorings, and off-gassing coffee bins or packages. Determinants contributing to higher exposures to both analytes in all task models included sum of all open storage sources and average percent of coffee production as ground coffee. Additionally, flavoring ground coffee and flavoring during survey contributed to notably higher exposures for both analytes in most, but not all task groups. Alternatively, general exhaust ventilation contributed to lower exposures in all but two models. Additionally, among facilities that flavored, local exhaust ventilation during flavoring processes contributed to lower 2,3-pentanedione exposures during grinding and packaging tasks. Coffee production facilities can consider implementing additional exposure controls for processes, sources, and task-based determinants associated with higher exposures to diacetyl and 2,3-pentanedione, such as isolating, enclosing, and directly exhausting grinders, flavoring mixers, and open storage of off-gassing whole bean and ground coffee, to reduce exposures and minimize risks for lung disease among workers.

BACKGROUND: While other studies have reported estimates of COVID-19 vaccine uptake by broad occupational group, little is known about vaccine uptake by detailed occupational category. METHODS: Data on COVID-19 vaccination were provided by US adults ages ≥18 years old who responded to the Facebook/Delphi Group COVID-19 Trends and Impact Survey (Delphi US CTIS) in April-May 2021, reported working for pay in the past 4 weeks, and answered questions about their COVID-19 vaccine status. Percentages of occupational groups reporting having had at least one COVID-19 vaccination were weighted to resemble the US general population and calculated for 23 major occupational groups and 120 detailed occupational categories in 15 major groups. RESULTS: COVID-19 vaccine uptake for all 828,401 working adult respondents was 73.6%. Uptake varied considerably across the 23 major occupational groups, from 45.7% for Construction and Extraction to 87.9% for Education, Training, and Library. Percentage vaccinated was also very low for Installation, Maintenance, and Repair at 52.1% and Farming, Fishing, and Forestry at 53.9%. Among the 120 detailed occupational categories, the highest percentage vaccinated was 93.9% for Postsecondary Teacher and the three lowest values were 39.1% for Any Extraction Worker in Oil, Gas, Mining, or Quarrying; 40.1% for Vehicle or Mobile Equipment Mechanic, Installer, or Repairer; and 42.0% for Any Construction Trades Worker. CONCLUSION: Low vaccination percentages were seen in many US occupations by the end of May 2021, early in the period of widespread availability of vaccines for adults. These findings could help inform the deployment of occupation-specific vaccinepromotion activities during future viral epidemics and pandemics.

OBJECTIVE: Farmers have an increased risk for chronic bronchitis and airflow obstruction. The objective of this study was to investigate the association of these health outcomes with farm activities. METHODS: We evaluated the Keokuk County Rural Health Study (KCRHS) enrollment data for farm activities and the two health outcomes chronic bronchitis based on self-reported symptoms and airflow obstruction based on spirometry. We used logistic regression to model the health outcomes, yielding an odds ratio (OR) and 95% confidence interval (95% CI) for farm activities while adjusting for potential confounders and other risk factors. RESULTS: Of the 1234 farmers, 104 (8.4%) had chronic bronchitis, 75 (6.1%) fulfilled the criteria for airflow obstruction, and the two outcomes overlapped by 18 participants. Chronic bronchitis without airflow obstruction (n=86) had a statistically significant association with crop storage insecticides (OR 3.1, 95% CI 1.6, 6.1) and a low number of years (3) worked with turkeys (OR 3.3, 95% CI 1.2, 9.4). The latter result should be interpreted with caution because it is based on a small number of cases (n=5). Airflow obstruction with or without chronic bronchitis (n=75) was significantly associated with ever working in a hog or chicken confinement setting (OR 2.2, 95% CI 1.0, 4.5). CONCLUSIONS: These results suggest that work with crop storage insecticides or turkeys may increase the risk for chronic bronchitis and work in hog or chicken confinement may increase the risk for airflow obstruction.

Early in the COVID-19 pandemic, demand for N95 respirators far exceeded the supply, leading to widespread shortages. Initially, the US Centers for Disease Control and Prevention did not recommend N95 respirators in nonhealthcare settings, in order to reserve them for healthcare workers. As N95s became more available, the recommendations were updated in May 2021 to include N95 respirators for nonhealthcare settings. In this study, we estimated the numbers of N95s needed for nonhealthcare essential workers in the United States. This information is valuable for crisis preparedness and planning for future large-scale communicable respiratory infectious disease epidemics or pandemics. We adapted a spreadsheet-based tool originally built to estimate the potential demand for N95 respirators during an influenza pandemic. We defined nonhealthcare essential occupations according to the 2020 US Department of Homeland Security guidance and used US Bureau of Labor Statistics employment numbers and Occupational Information Network data as model parameters. We modeled minimum, intermediate, and maximum N95 provision scenarios (as 1, 2, and 5 N95 respirators, respectively) per week per worker, for pandemic durations of 15 and 40 weeks. For 85.15 million nonhealthcare essential workers during a 15-week pandemic, an estimated 1.3 billion N95 respirators would be needed under minimum provision scenarios, 2.6 billion for intermediate provision, and 6.4 billion for maximum provision. During a 40-week pandemic, these estimates increased to 3.4 billion, 6.8 billion, and 17 billion. Public health authorities and policymakers can use these estimates when considering workplace respirator-wearing practices, including prioritization of allocation, for nonhealthcare essential workers. Our novel spreadsheet-based tool can also be used to quickly generate estimates of other preparedness and response equipment.

Coffee production is a global industry with roasteries throughout the world. Workers in this industry are exposed to complex mixtures of gases, dusts, and vapors including carbon monoxide, carbon dioxide, coffee dust, allergens, alpha-diketones, and other volatile organic compounds (VOCs). Adverse respiratory health outcomes such as respiratory symptoms, reduced pulmonary function, asthma, and obliterative bronchiolitis can occur among exposed workers. In response to health hazard evaluations requests received from 17 small- to medium-sized coffee facilities across the United States, the National Institute for Occupational Safety and Health conducted investigations during 2016-2017 to understand the burden of respiratory abnormalities, exposure characteristics, relationships between exposures and respiratory effects, and opportunities for exposure mitigation. Full-shift, task-based, and instantaneous personal and area air samples for diacetyl, 2,3-pentanedione and other VOCs were collected, and engineering controls were evaluated. Medical evaluations included questionnaire, spirometry, impulse oscillometry, and fractional exhaled nitric oxide. Exposure and health assessments were conducted using standardized tools and approaches, which enabled pooling data for aggregate analysis. The pooled data provided a larger population to better address the requestors' concern of the effect of exposure to alpha-diketones on the respiratory heath of coffee workers. This paper describes the rationale for the exposure and health assessment strategy, the approach used to achieve the study objectives, and its advantages and limitations.

Occupational exposure to diacetyl, a butter flavor chemical, can result in obliterative bronchiolitis. Obliterative bronchiolitis is characterized by exertional dyspnea, fixed airflow obstruction, and histopathologic constrictive bronchiolitis, with bronchiolar wall fibrosis leading to luminal narrowing and obliteration. We describe a case of advanced lung disease with histopathology distinct from obliterative bronchiolitis in a 37-year-old male coffee worker following prolonged exposure to high levels of diacetyl and the related compound 2,3-pentanedione, who had no other medical, avocational, or occupational history that could account for his illness. He began working at a coffee facility in the flavoring room and grinding area in 2009. Four years later he moved to the packaging area but continued to flavor and grind coffee at least 1 full day per week. He reported chest tightness and mucous membrane irritation when working in the flavoring room and grinding area in 2010. Beginning in 2014, he developed dyspnea, intermittent cough, and a reduced sense of smell without a work-related pattern. In 2016, spirometry revealed a moderate mixed pattern that did not improve with bronchodilator. Thoracoscopic lung biopsy results demonstrated focal mild cellular bronchiolitis and pleuritis, and focal peribronchiolar giant cells/granulomas, but no evidence of constrictive bronchiolitis. Full-shift personal air-samples collected in the flavoring and grinding areas during 2016 measured diacetyl concentrations up to 84-fold higher than the recommended exposure limit. Medical evaluations indicate this worker developed work-related, airway-centric lung disease, most likely attributable to inhalational exposure to flavorings, with biopsy findings not usual for obliterative bronchiolitis. Clinicians should be aware that lung pathology could vary considerably in workers with suspected flavoring-related lung disease.

Introduction: This paper describes occupations in the U.S. that involve close contact with others and whether the work is outdoors or indoors (risk factors for coronavirus disease 2019 [COVID- 19]), including the distribution of Black and Hispanic workers over these occupations. Methods: U.S. data released from 2014 to 2019 on employment, proximity to others at work, outdoor or indoor work, and Black and Hispanic worker percentages for occupations were used. Occupations were assigned to 6 categories defined as low, medium, or high physical closeness (proximity) at work and outdoor or indoor work. Three of the 6 categories represent higher risk for exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): medium proximity indoor, high proximity outdoor, and high proximity indoor exposure. Results: A high proportion of U.S. workers may be at higher risk for exposure to SARS-CoV-2 because their occupations involve either high proximity to others indoors and outdoors (25.2%, 36.5 million workers) or medium proximity indoors (48%, 69.6 million workers). There is differential distribution of proximity and outdoor/indoor work by occupation, which disproportionately affects Black and Hispanic workers in some occupations. Conclusions: Implementation of COVID-19 preventive measures in work settings should be based on occupation-specific risk factors, including the extent of proximity to others and whether the work is conducted outdoors or indoors. It is important that communication messages are tailored to the languages and preferred media of the workforce.

Characterizing indoor microbial communities using molecular methods provides insight into bacterial assemblages present in environments that can influence occupants' health. We conducted an environmental assessment as part of an epidemiologic study of 50 elementary schools in a large city in the northeastern USA. We vacuumed dust from the edges of the floor in 500 classrooms accounting for 499 processed dust aliquots for 16S Illumina MiSeq sequencing to characterize bacterial assemblages. DNA sequences were organized into operational taxonomic units (OTUs) and identified using a database derived from the National Center for Biotechnology Information. Bacterial diversity and ecological analyses were performed at the genus level. We identified 29 phyla, 57 classes, 148 orders, 320 families, 1193 genera, and 2045 species in 3073 OTUs. The number of genera per school ranged from 470 to 705. The phylum Proteobacteria was richest of all while Firmicutes was most abundant. The most abundant order included Lactobacillales, Spirulinales, and Clostridiales. Halospirulina was the most abundant genus, which has never been reported from any school studies before. Gram-negative bacteria were more abundant and richer (relative abundance = 0.53; 1632 OTUs) than gram-positive bacteria (0.47; 1441). Outdoor environment-associated genera were identified in greater abundance in the classrooms, in contrast to homes where human-associated bacteria are typically more abundant. Effects of school location, degree of water damage, building condition, number of students, air temperature and humidity, floor material, and classroom's floor level on the bacterial richness or community composition were statistically significant but subtle, indicating relative stability of classroom microbiome from environmental stress. Our study indicates that classroom floor dust had a characteristic bacterial community that is different from typical house dust represented by more gram-positive and human-associated bacteria. Health implications of exposure to the microbiomes in classroom floor dust may be different from those in homes for school staff and students. Video abstract.

Roasted coffee and many coffee flavorings emit volatile organic compounds (VOCs) including diacetyl and 2,3-pentanedione. Exposures to VOCs during roasting, packaging, grinding, and flavoring coffee can negatively impact the respiratory health of workers. Inhalational exposures to diacetyl and 2,3-pentanedione can cause obliterative bronchiolitis. This study summarizes exposures to and emissions of VOCs in 17 coffee roasting and packaging facilities that included 10 caf&#233;s. We collected 415 personal and 760 area full-shift, and 606 personal task-based air samples for diacetyl, 2,3-pentanedione, 2,3-hexanedione, and acetoin using silica gel tubes. We also collected 296 instantaneous activity and 312 instantaneous source air measurements for 18 VOCs using evacuated canisters. The highest personal full-shift exposure in part per billion (ppb) to diacetyl [geometric mean (GM) 21 ppb; 95th percentile (P95) 79 ppb] and 2,3-pentanedione (GM 15 ppb; P95 52 ppb) were measured for production workers in flavored coffee production areas. These workers also had the highest percentage of measurements above the NIOSH Recommended Exposure Limit (REL) for diacetyl (95%) and 2,3-pentanedione (77%). Personal exposures to diacetyl (GM 0.9 ppb; P95 6.0 ppb) and 2,3-pentanedione (GM 0.7 ppb; P95 4.4 ppb) were the lowest for non-production workers of facilities that did not flavor coffee. Job groups with the highest personal full-shift exposures to diacetyl and 2,3-pentanedione were flavoring workers (GM 34 and 38 ppb), packaging workers (GM 27 and 19 ppb) and grinder operator (GM 26 and 22 ppb), respectively, in flavored coffee facilities, and packaging workers (GM 8.0 and 4.4 ppb) and production workers (GM 6.3 and 4.6 ppb) in non-flavored coffee facilities. Baristas in caf&#233;s had mean full-shift exposures below the RELs (GM 4.1 ppb diacetyl; GM 4.6 ppb 2,3-pentanedione). The tasks, activities, and sources associated with flavoring in flavored coffee facilities and grinding in non-flavored coffee facilities, had some of the highest GM and P95 estimates for both diacetyl and 2,3-pentanedione. Controlling emissions at grinding machines and flavoring areas and isolating higher exposure areas (e.g., flavoring, grinding, and packaging areas) from the main production space and from administrative or non-production spaces is essential for maintaining exposure control.

INTRODUCTION: Workers' exposure to metalworking fluid (MWF) has been associated with respiratory disease. As part of a public health investigation of a manufacturing facility, we performed paired environmental and human sampling to evaluate cross-pollination of microbes between environment and host and possible effects on lung pathology present among workers. METHODS: Workplace environmental microbiota was evaluated in air and MWF samples. Human microbiota was evaluated in lung tissue samples from workers with respiratory symptoms found to have lymphocytic bronchiolitis and alveolar ductitis with B-cell follicles and emphysema, lung tissue controls, and in skin, nasal and oral samples from 302 workers from different areas of the facility. In vitro effects of MWF exposure on murine B-cells were assessed. RESULTS: Increased similarity of microbial composition was found between MWF samples and lung tissue samples of case workers compared to controls. Among workers in different locations within the facility, those that worked in machine shop area had skin, nasal and oral microbiota more closely related to the microbiota present in MWF samples. Lung samples from four index cases, and skin and nasal samples from workers in machine shop area were enriched with Pseudomonas, the dominant taxa in MWF. Exposure to used MWF stimulated murine B-cell proliferation in vitro, a hallmark cell subtype found in pathology of index cases. CONCLUSIONS: Evaluation of a manufacturing facility with a cluster of workers with respiratory disease supports cross-pollination of microbes from MWF to humans and suggests the potential for exposure to these microbes to be a health hazard.

A recent article reported that occupational exposure to vapor-gas, dust, and fumes (VGDF) was more common in a sample of rural adults than in a sample of adults in urban settings. In another study of the same urban adults, airflow obstruction (AO) was associated with occupational VGDF and the combination of smoking and occupational exposure. The goal of the current study was to determine if similar associations were evident in the sample of rural adults. We analyzed enrollment data from the Keokuk County Rural Health Study (KCRHS), which investigated the health of rural residents in Iowa. We used the same methods as the study of urban adults. A job-exposure matrix (JEM) assigned an occupational VGDF exposure level based on each participants' last reported job. The health outcome was AO, defined as both the forced expiratory volume in one second (FEV1) and the FEV1/forced vital capacity (FVC) ratio < lower limit of normal. Of the 1699 KCRHS participants, 436 (25.7%) had high total VGDF occupational exposure, 661 (38.9%) had ever smoked cigarettes, and 110 (6.5%) had AO. The crude frequency of AO increased across the joint categories of smoking (never, ever) and high exposure (no, yes) (p < 0.05 for linear trend). After adjusting for potential confounders, AO was associated with high total occupational VGDF exposure only among smokers (OR = 1.81, 95% CI 1.002 to 3.26). In conclusion, the association of AO with occupational exposure in the current study of rural adults was similar to what was previously observed among urban adults.

OBJECTIVE: The aim of this study was to compare spirometry results in microwave popcorn and flavoring manufacturing workers. METHODS: We used NIOSH data on current and former microwave popcorn workers (MPWs) and surveillance data on flavoring manufacturing workers (FMWs). RESULTS: Former MPW had higher prevalence of mixed and high severity abnormalities, some had excessive lung function drops. Current MPW had lowest occurrence of excessive lung function drops. FMW with excessive drops and spirometric abnormalities at last test had developed a restrictive pattern. Spirometric abnormalities and excessive drops were associated with work-related factors. CONCLUSION: There was evidence of a healthy worker survivor effect in MPW. Importantly, removal from exposure did not always stabilize lung function decline indicating a need for continued monitoring. The development of a restrictive pattern should raise the level of suspicion for possible work-related disease in flavoring-exposed workers.

OBJECTIVES: Four machine manufacturing facility workers had a novel occupational lung disease of uncertain aetiology characterised by lymphocytic bronchiolitis, alveolar ductitis and emphysema (BADE). We aimed to evaluate current workers' respiratory health in relation to job category and relative exposure to endotoxin, which is aerosolised from in-use metalworking fluid. METHODS: We offered a questionnaire and spirometry at baseline and 3.5 year follow-up. Endotoxin exposures were quantified for 16 production and non-production job groups. Forced expiratory volume in one second (FEV1) decline >/=10% was considered excessive. We examined SMRs compared with US adults, adjusted prevalence ratios (aPRs) for health outcomes by endotoxin exposure tertiles and predictors of excessive FEV1 decline. RESULTS: Among 388 (89%) baseline participants, SMRs were elevated for wheeze (2.5 (95% CI 2.1 to 3.0)), but not obstruction (0.5 (95% CI 0.3 to 1.1)). Mean endotoxin exposures (range: 0.09-28.4 EU/m(3)) were highest for machine shop jobs. Higher exposure was associated with exertional dyspnea (aPR=2.8 (95% CI 1.4 to 5.7)), but not lung function. Of 250 (64%) follow-up participants, 11 (4%) had excessive FEV1 decline (range: 403-2074 mL); 10 worked in production. Wheeze (aPR=3.6 (95% CI 1.1 to 12.1)) and medium (1.3-7.5 EU/m(3)) endotoxin exposure (aPR=10.5 (95% CI 1.3 to 83.1)) at baseline were associated with excessive decline. One production worker with excessive decline had BADE on subsequent lung biopsy. CONCLUSIONS: Lung function loss and BADE were associated with production work. Relationships with relative endotoxin exposure indicate work-related adverse respiratory health outcomes beyond the sentinel disease cluster, including an incident BADE case. Until causative factors and effective preventive strategies for BADE are determined, exposure minimisation and medical surveillance of affected workforces are recommended.

Introduction: Respiratory hazards in the coffee roasting and packaging industry can include asthmagens such as green coffee bean and other dust and alpha-diketones such as diacetyl and 2,3-pentanedione that can occur naturally from roasting coffee or artificially from addition of flavoring to coffee. We sought to describe the burden of respiratory abnormalities among workers at 17 coffee roasting and packaging facilities. Methods: We completed medical surveys at 17 coffee roasting and packaging facilities that included interviewer-administered questionnaires and pulmonary function testing. We summarized work-related symptoms, diagnoses, and spirometry testing results among all participants. We compared health outcomes between participants who worked near flavoring and who did not. Results: Participants most commonly reported nose and eye symptoms, and wheeze, with a work-related pattern for some. Symptoms and pulmonary function tests were consistent with work-related asthma in some participants. About 5% of workers had abnormal spirometry and most improved after bronchodilator. Health outcomes were similar between employees who worked near flavoring and who did not, except employees who worked near flavoring reported more chronic bronchitis and ever receiving a diagnosis of asthma than those who did not work near flavoring. Conclusion: The symptoms and patterns likely represent overlapping health effects of different respiratory hazards, including green coffee bean and other dust that can contribute to work-related asthma, and diacetyl and 2,3-pentanedione that can contribute to obliterative bronchiolitis. Healthcare providers and occupational health and safety practitioners should be aware that workers at coffee roasting and packaging facilities are potentially at risk for occupational lung diseases.

BACKGROUND: A cluster of severe lung disease occurred at a manufacturing facility making industrial machines. We aimed to describe disease features and workplace exposures. METHODS: Clinical, functional, radiologic, and histopathologic features were characterized. Airborne concentrations of thoracic aerosol, metalworking fluid, endotoxin, metals, and volatile organic compounds were measured. Facility airflow was assessed using tracer gas. Process fluids were examined using culture, polymerase chain reaction, and 16S ribosomal RNA sequencing. RESULTS: Five previously healthy male never-smokers, ages 27 to 50, developed chest symptoms from 1995 to 2012 while working in the facility's production areas. Patients had an insidious onset of cough, wheeze, and exertional dyspnea; airflow obstruction (mean FEV1 = 44% predicted) and reduced diffusing capacity (mean = 53% predicted); and radiologic centrilobular emphysema. Lung tissue demonstrated a unique pattern of bronchiolitis and alveolar ductitis with B-cell follicles lacking germinal centers, and significant emphysema for never-smokers. All had chronic dyspnea, three had a progressive functional decline, and one underwent lung transplantation. Patients reported no unusual nonoccupational exposures. No cases were identified among nonproduction workers or in the community. Endotoxin concentrations were elevated in two air samples; otherwise, exposures were below occupational limits. Air flowed from areas where machining occurred to other production areas. Metalworking fluid primarily grew Pseudomonas pseudoalcaligenes and lacked mycobacterial DNA, but 16S analysis revealed more complex bacterial communities. CONCLUSION: This cluster indicates a previously unrecognized occupational lung disease of yet uncertain etiology that should be considered in manufacturing workers (particularly never-smokers) with airflow obstruction and centrilobular emphysema. Investigation of additional cases in other settings could clarify the cause and guide prevention.

In August 2017, Hurricane Harvey caused unprecedented flooding and devastation to the Houston metropolitan area (1). Mold exposure was a serious concern because investigations after Hurricanes Katrina and Rita (2005) had documented extensive mold growth in flood-damaged homes (2,3). Because mold exposure can cause serious illnesses known as invasive mold infections (4,5), and immunosuppressed persons are at high risk for these infections (6,7), several federal agencies recommend that immunosuppressed persons avoid mold-contaminated sites (8,9). To assess the extent of exposure to mold and flood-damaged areas among persons at high risk for invasive mold infections after Hurricane Harvey, CDC and Texas health officials conducted a survey among 103 immunosuppressed residents in Houston. Approximately half of the participants (50) engaged in cleanup of mold and water-damaged areas; these activities included heavy cleanup (23), such as removing furniture or removing drywall, or light cleanup (27), such as wiping down walls or retrieving personal items. Among immunosuppressed persons who performed heavy cleanup, 43% reported wearing a respirator, as did 8% who performed light cleanup. One participant reported wearing all personal protective equipment (PPE) recommended for otherwise healthy persons (i.e., respirator, boots, goggles, and gloves). Immunosuppressed residents who are at high risk for invasive mold infections were exposed to mold and flood-damaged areas after Hurricane Harvey; recommendations from health care providers to avoid exposure to mold and flood-damaged areas could mitigate the risk to immunosuppressed persons.

BACKGROUND: Non-malignant respiratory disease (NMRD) cases have occurred among rubber manufacturing workers. We examined exposure to rubber manufacturing emissions as a risk factor for NMRD. METHODS: From a systematic literature review, we identified case reports and assessed cross-sectional and mortality studies for strength of evidence of positive association (strong, intermediate, non-significant positive association, none) between exposure to rubber manufacturing emissions and NMRD-related morbidity and mortality, and conducted two meta-analyses. RESULTS: We analyzed 62 articles. We identified 11 cases of NMRD. Nine (30%) of 30 cross-sectional studies and one (4%) of 26 mortality studies had strong evidence. The summary odds ratio and SMR for the cross-sectional and mortality meta-analyses were 3.83 (95% confidence interval [CI], 2.28-6.51) and 0.90 (95%CI, 0.82-0.99), respectively. CONCLUSION: Available evidence supports rubber manufacturing emissions as a potential risk factor for NMRD-related morbidity. Further investigations with longer follow-up periods and inclusion of short-tenured workers could further define risks for NMRD and identify prevention strategies.

OBJECTIVES: Diacetyl, a butter flavour compound used in food and flavouring production, is a respiratory toxin. We characterised the burden of respiratory abnormalities in workers at popcorn and flavouring manufacturing facilities that used diacetyl as evaluated through US National Institute for Occupational Safety and Health (NIOSH) health hazard evaluations. METHODS: We performed analyses describing the number and percentage of current and former workers from popcorn and flavouring manufacturing facilities where NIOSH administered a respiratory health questionnaire and spirometry testing who met case definitions of suspected flavouring-related lung disease. Case definitions were pathologist reported: lung biopsy pathology report stating supportive of/consistent with constrictive bronchiolitis or bronchiolitis obliterans; probable: obstructive/mixed spirometric pattern with forced expiratory volume in 1 s (FEV1) <60% predicted; possible: obstructive/mixed spirometric pattern with FEV1 >/=60% or any spirometric restriction; symptoms only: normal spirometry plus exertional dyspnoea or usual cough. RESULTS: During 2000-2012, NIOSH collected questionnaire and spirometry data on 1407 workers (87.0% current, 13.0% former) at nine facilities in eight states. After applying case definitions, 4 (0.3%) were classified as pathologist reported, 48 (3.4%) as probable, 234 (16.6%) as possible and 404 (28.7%) as symptoms only. The remaining 717 (51.0%) workers had normal spirometry without exertional dyspnoea or usual cough. Seven of 11 workers with biopsies did not meet the pathologist-reported case definition, although four met probable and three met possible. CONCLUSIONS: This approach demonstrates the substantial burden of respiratory abnormalities in these workers. A similar approach could quantify the burden of respiratory abnormalities in other industries that use diacetyl.

Recent developments in molecular and chemical methods have enabled the analysis of fungal DNA and secondary metabolites, often produced during fungal growth, in environmental samples. We compared three fungal analytical methods by analyzing floor dust samples collected from an office building for fungi using viable culture, internal transcribed spacer (ITS) sequencing, and secondary metabolites using liquid chromatography-tandem mass spectrometry. Of the 32 metabolites identified, 29 had a potential link to fungi with levels ranging from 0.04 (minimum for alternariol monomethylether) to 5,700 ng/g (maximum for neoechinulin A). The number of fungal metabolites quantified per sample ranged from eight to sixteen (average=13/sample). We identified 216 fungal operational taxonomic units (OTUs) with the number per sample ranging from six to twenty-nine (average=18/sample). We identified 37 fungal species using culture and the number per sample ranged from two to thirteen (average=eight/sample). Agreement in identification between ITS sequencing and culturing was weak (kappa=-0.12-0.27). The number of cultured fungal species poorly correlated with OTUs, which did not correlate with the number of metabolites. These suggest that using multiple measurement methods may provide an improved understanding of fungal exposures in indoor environments and that secondary metabolites may be considered as an additional source of exposure. This article is protected by copyright. All rights reserved.

There is limited information on the natural history of building occupants' health in relation to attempts to remediate moisture damage. We examined changes in respiratory and non-respiratory symptoms in 1,175 office building occupants over seven years with multiple remediation attempts. During each of four surveys, we categorized participants using a severity score: 0 = asymptomatic; 1 = mild, symptomatic in the last 12 months, but not frequently in the last 4 weeks; 2 = severe, symptomatic at least once weekly in the last 4 weeks. Building-related symptoms were defined as improving away from the building. We used random intercept models adjusted for demographics, smoking, building tenure, and microbial exposures to estimate temporal changes in the odds of building-related symptoms or severity scores independent of the effect of microbial exposures. Trend analyses of combined mild/severe symptoms showed no changes in the odds of respiratory symptoms but significant improvement in non-respiratory symptoms over time. Separate analyses showed increases in the odds of severe respiratory symptoms (odds ratio/year = 1.151.16, p-values<0.05) and severity scores (0.02/year, p-values<0.05) for wheezing and shortness of breath on exertion, due to worsening of participants in the mild symptom group. For non-respiratory symptoms, we found no changes in the odds of severe symptoms but improvement in severity scores (-0.04-0.01/year, p-values<0.05) and the odds for mild fever and chills, excessive fatigue, headache, and throat symptoms (0.65-0.79/year, p-values<0.05). Our study suggests that after the onset of respiratory and severe non-respiratory symptoms associated with dampness/mold, remediation efforts might not be effective in improving occupants' health.