Self-reported respiratory health symptoms and respiratory protection behaviors of young adult hog producers in the United States.

INTRODUCTION AND METHODS: In this study, we evaluated self-reported respiratory symptoms during agricultural work, respiratory protection use and experience, and perceived value of receiving respirators using Gear Up for Ag Health and Safety Program™ pre- and post-surveys from 703 to 212 young adult hog producers in the United States. To our knowledge, this is one of the most extensive survey data sets on self-reported respiratory symptoms and respiratory protection behaviors of collegiate-aged young adults working in US livestock production. RESULTS: About one-third (37%) of young adult hog producers stated that they have experienced cough, shortness of breath, fever, and chills after working in dusty areas on the farm. Most (76.2%) stated that they were already "always" or "sometimes" wearing filtering facepiece (N95-style) respirators, even before participating in an outreach program. About one-third (30%) reported experience wearing a cartridge-style respirator but only 5% reported having been fit-tested for a respirator. Young adult male producers were significantly more likely to report use of both respirator types when compared to females, both before and after the program. Male producers were also more likely than females to engage in high-risk farm tasks where respirators are recommended, such as cleaning out grain bins and mixing or grinding feed. Following an educational program, males and females reported using the respirators that they received at similar rates, and 20% of overall participants purchased additional respiratory protection. DISCUSSION: The study found that young adult hog producers in postsecondary education are already wearing respirators with some frequency and at rates higher than previously reported by agricultural workers. More research is needed to make effective task-based respirator-use recommendations and investigate some significant gender differences among young adult hog producers observed in this study.

Urban Particulate Matter Impairment of Airway Surface Liquid-Mediated Coronavirus Inactivation.

Air pollution particulate matter (PM) is associated with SARS-CoV-2 infection and severity, although mechanistic studies are lacking. We tested whether airway surface liquid (ASL) from primary human airway epithelial cells is antiviral against SARS-CoV-2 and human alphacoronavirus 229E (CoV-229E) (responsible for common colds), and whether PM (urban, indoor air pollution [IAP], volcanic ash) affected ASL antiviral activity. ASL inactivated SARS-CoV-2 and CoV-229E. Independently, urban PM also decreased SARS-CoV-2 and CoV-229E infection, and IAP PM decreased CoV-229E infection. However, in combination, urban PM impaired ASL's antiviral activity against both viruses, and the same effect occurred for IAP PM and ash against SARS-CoV-2, suggesting that PM may enhance SARS-CoV-2 infection.

OSHA Voluntary Respirator Use: Challenges incurred with use of N95 filtering facepiece respirators during the COVID-19 pandemic.

This article discusses several lessons learned in dealing with the interpretation of the Occupational Health and Safety Administration (OSHA) Voluntary Use provision of the Respiratory Health Standard at health-care facilities during the COVID-19 pandemic in the United States. This includes (but is not limited to) (a) confusion about OSHA policy and procedures when health-care workers brought outside personal protective equipment (PPE; N95 filtering facepiece respirators) into the workplace; (b) challenges in adhering to guidelines stated in Appendix D of the Respiratory Protection Standard; (c) difficulty in achieving respirator fit testing for workers; and (d) vague or inconsistent determination of "non-hazardous" environments (concerning COVID-laden droplets and aerosols). The purpose was to identify gaps in knowledge to help policy makers, enforcement personnel, safety managers, and health-care workers in the United States prepare for similar future events involving PPE shortages.

Reliability of observational- and machine-based teat hygiene scoring methodologies.

Removal of teat-end debris is one of the most critical steps in the premilking process. We aimed to estimate inter- and intra-rater reliability of an observation-based rating scale of dairy parlor worker teat-cleaning performance. A nonrandom sample of 8 experienced raters provided teat swab debris ratings scored on a 4-point ordinal visual scale for 175 teat swab images taken immediately after teat cleaning and before milking unit attachment. To overcome the uncertainty associated with visual inspection and observation-based rating scales, we assessed the reliability of an automated observer-independent method to assess teat-end debris using digital image processing and machine learning techniques to quantify the type and amount of debris material present on each teat swab image. Cohen's kappa coefficient (κ) was used to assess inter-rater score agreement on 175 teat swab images, and the intraclass correlation coefficient was used to assess both intra-rater score agreement and machine reliability. The reliability of debris scoring of teat swabs by raters was low (overall κ = 0.43), whereas the machine-based rating system demonstrated near-perfect reliability (Pearson r > 0.99). Our findings suggest that machine-based rating systems of worker performance are much more reliable than observational-based methods when evaluating premilking teat cleanliness. Teat swab image analysis technology can be further developed for training and quality control purposes to enable more efficient, reliable, and independent feedback on worker milking performance. As automated technologies are becoming more popular on dairy farms, machine-based teat cleanliness scoring could also be incorporated into automated milking systems.

Pulmonary function and airway inflammation among dairy parlor workers after exposure to inhalable aerosols.

BACKGROUND: Inhalation exposure to organic dust causes lung inflammation among agricultural workers. Due to changes in production and work organization, task-based inhalation exposure data, including novel lung inflammation biomarkers, will inform exposure recommendations for dairy farm workers. METHODS: Linear regression was used to estimate the associations of airborne exposure to dust concentration, endotoxin, and muramic acid with pulmonary outcomes (i.e., FEV1 , exhaled nitric oxide). Logistic regression was used to estimate associations with self-reported pulmonary symptoms. RESULTS: Mean exposure concentration to inhalable dust, endotoxin, and muramic acid were 0.55 mg/m3 , 118 EU/m3 , and 3.6 mg/m3 , respectively. We found cross-shift differences for exhaled nitric oxide (P = 0.005) and self-reported pulmonary symptoms (P = 0.008) but no association of exposure with respiratory outcomes. CONCLUSIONS: Inhalation exposures during parlor tasks, which were lower than previously reported and were not associated with cross-shift measures of pulmonary health among dairy workers. Modern milking parlor designs may be contributing to lower inhalation exposure. Am. J. Ind. Med. 60:255-263, 2017. © 2017 Wiley Periodicals, Inc.

Full-shift and task-specific upper extremity muscle activity among US large-herd dairy parlour workers.

US large-herd dairy parlour workers experience a high prevalence of musculoskeletal symptoms in the upper extremity. The purpose of this study was to estimate and compare full-shift and task-specific muscle activity of the upper extremity among parlour workers. Surface electromyography data were recorded continuously throughout a full work shift for each participant (n = 60). For a subset of participants (n = 33), muscular effort was estimated for milking task cycles. Lower muscle activity levels and higher per cent muscular rest was observed among rotary parlour participants as compared to herringbone and parallel parlour participants for anterior deltoid, forearm flexor and forearm extensor muscles. These findings suggest rotary parlours may offer workstation designs or work organisational dynamics which may be more beneficial to the health and performance of the worker, as compared to parallel or herringbone parlours. Practitioner Summary: Study findings suggest milking parlour configurations present different biomechanical demands on workers which may influence worker health and performance. Our findings will enable more informed decisions regarding both engineering (e.g. parlour configuration or milking equipment) and administrative (e.g. work organisation) control strategies for large-herd milking parlours.

Effect of a novel teat preparation system on upper extremity muscle activity among U.S. large-herd dairy parlor workers.

BACKGROUND: Dairy production in the U.S. is moving towards large-herd milking operations resulting in an increase in task specialization and work demands. Large-herd dairy parlor workers experience a high prevalence of musculoskeletal symptoms in the upper extremity. The purpose of this study is to evaluate the effects of an alternative teat scrubber (TS) cow preparation method on upper extremity muscle activity among large-herd parlor workers, as well compare to muscle activity associated with conventional manual milking tasks. METHODS: Upper extremity muscle activity was recorded among U.S. large-herd parlor workers (n = 15) using surface electromyography. Participants performed multiple task cycles, using both conventional and TS methods. Muscle activity levels were then compared across conventional manual and TS milking tasks. RESULTS: Conventional manual milking tasks of dip, strip and wipe were associated higher muscle activity levels of the upper trapezius and anterior deltoid. Biceps muscle activity was greatest during teat dip and wipe. Forearm flexor and extensor muscle activity was greatest during teat wipe and dip. The TS system resulted in more desirable anterior deltoid EMG profiles, and less desirable biceps, forearm flexor and extensor profiles. CONCLUSIONS: Results suggest that the TS system is effective in reducing anterior deltoid muscle activation levels. The TS system also appears to result in increased biceps, forearm flexor and extensor muscle activation levels. Increases in muscle activation levels could be offset by reduced repetitiveness resulting from three conventional manual milking tasks being replaced with one TS task. RELEVANCE TO INDUSTRY: If parlor production requirements (e.g., quality and onsistency) are maintained while simultaneously reducing cumulative muscle loading and worker fatigue, then TS use should be considered in milking parlor operations.

Transcriptional mechanisms and protein kinase signaling mediate organic dust induction of IL-8 expression in lung epithelial and THP-1 cells.

Exposure to the agricultural work environment is a risk factor for the development of respiratory symptoms and chronic lung diseases. Inflammation is an important contributor to the pathogenesis of tissue injury and disease. Cellular and molecular mechanisms mediating lung inflammatory responses to agricultural dust are not yet fully understood. We studied the effects of poultry dust extract on molecular regulation of interleukin-8 (IL-8), a proinflammatory cytokine, in A549 and Beas2B lung epithelial and THP-1 monocytic cells. Our findings indicate that poultry dust extract potently induces IL-8 levels by increasing IL-8 gene transcription without altering IL-8 mRNA stability. Increase in IL-8 promoter activity was due to enhanced binding of activator protein 1 and NF-κB. IL-8 induction was associated with protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) activation and inhibited by PKC and MAPK inhibitors. IL-8 increase was not inhibited by polymyxin B or l-nitroarginine methyl ester, indicating lack of involvement of lipopolysaccharide and nitric oxide in the induction. Lung epithelial and THP-1 cells share common mechanisms for induction of IL-8 levels. Our findings identify key roles for transcriptional mechanisms and protein kinase signaling pathways for IL-8 induction and provide insights into the mechanisms regulating lung inflammatory responses to organic dust exposure.

Prevalence of work-related musculoskeletal symptoms among US large-herd dairy parlor workers.

BACKGROUND: Dairy production in the US is moving towards large-herd milking operations resulting in an increase in task specialization and work demands. METHODS: A modified version of the Standardized Nordic Questionnaire was administered to assess MSS prevalence among 452 US large-herd parlor workers. Worker demographics and MSS prevalences were assessed, and differences based on parlor configuration (i.e., herringbone, parallel, rotary) were computed. RESULTS: Three-fourths (76.4%) of parlor workers reported work-related MSS in at least one body part. Highest prevalences were reported in the upper extremity (55%). Herringbone workers reported a higher prevalence of MSS in the wrist/hand, and rotary workers reported higher prevalences of MSS in the neck, upper back, and shoulders. CONCLUSIONS: Our findings draw attention to higher work-related MSS in the upper extremity among dairy parlor workers. As the trend toward larger herd sizes on US dairy farms continues, the need for further health and safety research will increase.

Comparison of virus aerosol concentrations across a face shield worn on a healthcare personnel during a simulated patient cough.

BACKGROUND: Patients diagnosed with coronavirus disease 2019 (COVID-19) aerosolize severe acute respiratory coronavirus virus 2 (SARS-CoV-2) via respiratory efforts, expose, and possibly infect healthcare personnel (HCP). To prevent transmission of SARS-CoV-2 HCP have been required to wear personal protective equipment (PPE) during patient care. Early in the COVID-19 pandemic, face shields were used as an approach to control HCP exposure to SARS-CoV-2, including eye protection. METHODS: An MS2 bacteriophage was used as a surrogate for SARS-CoV-2 and was aerosolized using a coughing machine. A simulated HCP wearing a disposable plastic face shield was placed 0.41 m (16 inches) away from the coughing machine. The aerosolized virus was sampled using SKC biosamplers on the inside (near the mouth of the simulated HCP) and the outside of the face shield. The aerosolized virus collected by the SKC Biosampler was analyzed using a viability assay. Optical particle counters (OPCs) were placed next to the biosamplers to measure the particle concentration. RESULTS: There was a statistically significant reduction (P < .0006) in viable virus concentration on the inside of the face shield compared to the outside of the face shield. The particle concentration was significantly lower on the inside of the face shield compared to the outside of the face shield for 12 of the 16 particle sizes measured (P < .05). CONCLUSIONS: Reductions in virus and particle concentrations were observed on the inside of the face shield; however, viable virus was measured on the inside of the face shield, in the breathing zone of the HCP. Therefore, other exposure control methods need to be used to prevent transmission from virus aerosol.

Development of Shortened Enrichment Methods for Detection of Salmonella Typhimurium Spiked in Milk.

Rapid and accurate testing of pathogenic Salmonella enterica in dairy products could reduce the risk of exposure to the bacterial pathogens for consumers. This study aimed to reduce the assessment time needed for enteric bacteria recovery and quantification in food using the natural growth properties of Salmonella enterica Typhimurium (S. Typhimurium) in cow's milk and efficiently using rapid PCR methods. Over 5 h of 37 °C enrichment, culture and PCR methods measured increases in the non-heat-treated S. Typhimurium concentration at similar rates, with an average increase of 2.7 log10 CFU/mL between the start of enrichment and 5 h. In contrast, no bacteria were recovered by culture after S. Typhimurium in milk received heat treatment, and the number of gene copies of heat-treated Salmonella detected by PCR did not increase with the enrichment time. Thus, comparing culture and PCR data over just 5 h of enrichment time can detect and differentiate between replicating bacteria and dead bacteria.

Evaluation of face shields used during aerosol generating procedures.

Transnasal flexible laryngoscopy is considered an aerosol generating procedure. A negative pressure face shield (NPFS) was developed to control aerosol from the patient during laryngoscopy. The purpose of this study was to determine the effectiveness of the NPFS at controlling virus aerosol compared to a standard disposable plastic face shield. The face shields were placed on a simulated patient coughing machine. MS2 bacteriophage was used as a surrogate for SARS-CoV-2 and was aerosolized using the coughing machine. The aerosolized virus was sampled on the inside and outside of the face shields. The virus aerosol concentration was not significantly different between the inside and outside of the traditional plastic face shield (p = 0.12). However, the particle concentrations across all particle sizes measured were significantly decreased outside the face shield. The virus and particle concentrations were significantly decreased (p < 0.01) outside the NPFS operating at a flow rate of 38.6 L per minute (LPM). When the NPFS was operated at 10 LPM, virus concentrations were not significantly different (p = 0.09) across the face shield. However, the number particle concentrations across all particle sizes measured were significantly different (p < 0.05).

Utilizing pyrosequencing and quantitative PCR to characterize fungal populations among house dust samples.

Molecular techniques are an alternative to culturing and counting methods in quantifying indoor fungal contamination. Pyrosequencing offers the possibility of identifying unexpected indoor fungi. In this study, 50 house dust samples were collected from homes in the Yakima Valley, WA. Each sample was analyzed by quantitative PCR (QPCR) for 36 common fungi and by fungal tag-encoded flexible (FLX) amplicon pyrosequencing (fTEFAP) for these and additional fungi. Only 24 of the samples yielded amplified results using fTEFAP but QPCR successfully amplified all 50 samples. Over 450 fungal species were detected by fTEFAP but most were rare. Twenty-two fungi were found by fTEFAP to occur with at least an average of ≥0.5% relative occurrence. Many of these fungi seem to be associated with plants, soil or human skin. Combining fTEFAP and QPCR can enhance studies of fungal contamination in homes.

Bioaerosols generated from toilet flushing in rooms of patients with Clostridioides difficile infection.

BACKGROUND: Clostridioides difficile infection (CDI) is the most frequently reported hospital-acquired infection in the United States. Bioaerosols generated during toilet flushing are a possible mechanism for the spread of this pathogen in clinical settings. OBJECTIVE: To measure the bioaerosol concentration from toilets of patients with CDI before and after flushing. DESIGN: In this pilot study, bioaerosols were collected 0.15 m, 0.5 m, and 1.0 m from the rims of the toilets in the bathrooms of hospitalized patients with CDI. Inhibitory, selective media were used to detect C. difficile and other facultative anaerobes. Room air was collected continuously for 20 minutes with a bioaerosol sampler before and after toilet flushing. Wilcoxon rank-sum tests were used to assess the difference in bioaerosol production before and after flushing. SETTING: Rooms of patients with CDI at University of Iowa Hospitals and Clinics. RESULTS: Bacteria were positively cultured from 8 of 24 rooms (33%). In total, 72 preflush and 72 postflush samples were collected; 9 of the preflush samples (13%) and 19 of the postflush samples (26%) were culture positive for healthcare-associated bacteria. The predominant species cultured were Enterococcus faecalis, E. faecium, and C. difficile. Compared to the preflush samples, the postflush samples showed significant increases in the concentrations of the 2 large particle-size categories: 5.0 µm (P = .0095) and 10.0 µm (P = .0082). CONCLUSIONS: Bioaerosols produced by toilet flushing potentially contribute to hospital environmental contamination. Prevention measures (eg, toilet lids) should be evaluated as interventions to prevent toilet-associated environmental contamination in clinical settings.

Musculoskeletal symptoms of the neck and upper extremities among Iowa dairy farmers.

BACKGROUND: The prevalence of musculoskeletal symptoms (MSS) among U.S. dairy farmers is relatively unknown. The purpose of this study was to assess the prevalence of neck and upper extremity MSS, and to examine associations between symptoms and dairy operation activities among dairy farmers. METHODS: Questionnaires were mailed to randomly selected dairy farmers in the State of Iowa, USA. Demographic, site specific MSS, and dairy operation activity information was obtained. Odds ratios and 95% confidence intervals were estimated with logistic regression adjusting for potential confounders. RESULTS: Among the participants (N = 341), shoulder MSS were reported most frequently (54%). Neck MSS were significantly associated with manually feeding (OR(adj) = 2.29; 95% CI = 1.09-4.80) and tractors use (OR(adj) = 2.17; 95% CI = 1.05-4.50). Also, wrist/hand MSS were associated with manually cleaning animal stalls (OR(adj) = 1.96; 95% CI = 1.06-3.63). CONCLUSIONS: Neck and upper extremity MSS were common and associated with common dairy farming practices. Future studies need to more accurately assess exposures to physical risk factors for MSS so ergonomic interventions can be developed.

Bioaerosol concentrations generated from toilet flushing in a hospital-based patient care setting.

Background: In the United States, 1.7 million immunocompromised patients contract a healthcare-associated infection, annually. These infections increase morbidity, mortality and costs of care. A relatively unexplored route of transmission is the generation of bioaerosols during patient care. Transmission of pathogenic microorganisms may result from inhalation or surface contamination of bioaerosols. The toilet flushing of patient fecal waste may be a source of bioaerosols. To date, no study has investigated bioaerosol concentrations from flushing fecal wastes during patient care. Methods: Particle and bioaerosol concentrations were measured in hospital bathrooms across three sampling conditions; no waste no flush, no waste with flush, and fecal waste with flush. Particle and bioaerosol concentrations were measured with a particle counter bioaerosol sampler both before after a toilet flushing event at distances of 0.15, 0.5, and 1 m from the toilet for 5, 10, 15 min. Results: Particle concentrations measured before and after the flush were found to be significantly different (0.3-10 µm). Bioaerosol concentrations when flushing fecal waste were found to be significantly greater than background concentrations (p-value = 0.005). However, the bioaerosol concentrations were not different across time (p-value = 0.977) or distance (p-value = 0.911) from the toilet, suggesting that aerosols generated may remain for longer than 30 min post flush. Toilets produce aerosol particles when flushed, with the majority of the particles being 0.3 µm in diameter. The particles aerosolized include microorganisms remaining from previous use or from fecal wastes. Differences in bioaerosol concentrations across conditions also suggest that toilet flushing is a source of bioaerosols that may result in transmission of pathogenic microorganisms. Conclusions: This study is the first to quantify particles and bioaerosols produced from flushing a hospital toilet during routine patient care. Future studies are needed targeting pathogens associated with gastrointestinal illness and evaluating aerosol exposure reduction interventions.

New Institutional Theory and a Culture of Safety in Agriculture.

Health and safety professionals often call for an improved safety culture in agriculture. Such a shift would result in agricultural practices that prioritize safe work habits and see safety as both an effective means to improve production and a goal worth pursuing in its own right. This article takes an anthropological approach and demonstrates the potential for new institutional theory to conceptualize broader cultural change in agriculture. New institutional theory examines the roles of organizations and the ways that they inform and support broad social institutions. Using preliminary data from the agricultural lending industry in Iowa and integrated poultry production in Texas, this article considers the ability of these organizations to contribute to systemic change and an improved culture of safety in agriculture.

Effects of milking unit design on upper extremity muscle activity during attachment among U.S. large-herd parlor workers.

BACKGROUND: Large-herd dairy parlor workers experience a high prevalence of musculoskeletal symptoms in the upper extremity. The purpose of this study was to evaluate the effect of milking unit design on upper extremity muscle activity during milking unit attachment. METHODS: Upper extremity muscle activity was recorded among U.S. large-herd parlor workers (n=11) using surface electromyography. Participants performed several milking unit attachment cycles with each of six milking unit designs. Muscle activity levels were then compared between unit designs. RESULTS: Mean muscle activity levels (in %MVE) across milking units ranged from 6.8 to 8.2 for the upper trapezius, 8.2 to 10.3 for the anterior deltoid, 13.8 to 17.2 for the forearm flexors, and 9.9 to 12.4 for the forearm extensors. Pairwise comparisons between milking units did not reveal statistically significant differences in muscle activity levels across milking unit designs. However, a general pattern of higher muscle activity was observed with specific milking units. Milking unit weight, milk tube spread, and teat cup shape may explain differences in muscle activity levels. CONCLUSIONS: Milking unit design may influence muscle activity levels among parlor workers. Small reductions in muscle activity associated with milking unit design have the potential to delay the onset of fatigue or development of musculoskeletal health outcomes among parlor workers.

Airborne Influenza A Is Detected in the Personal Breathing Zone of Swine Veterinarians.

The 2009 H1N1 pandemic emphasized a need to evaluate zoonotic transmission of influenza A in swine production. Airborne influenza A virus has been detected in swine facilities during an outbreak. However, the personal exposure of veterinarians treating infected swine has not been characterized. Two personal bioaerosol samplers, the NIOSH bioaerosol sampler and the personal high-flow inhalable sampler head (PHISH), were placed in the breathing zone of veterinarians treating swine infected with either H1N1 or H3N2 influenza A. A greater number of viral particles were recovered from the NIOSH bioaerosol sampler (2094 RNA copies/m3) compared to the PHISH sampler (545 RNA copies/m3). In addition, the majority of viral particles were detected by the NIOSH bioaerosol sampler in the >4 µm size fraction. These results suggest that airborne influenza A virus is present in the breathing zone of veterinarians treating swine, and the aerosol route of zoonotic transmission of influenza virus should be further evaluated among agricultural workers.