Reports to OSHA of severe occupational injuries due to animals, 2015-2021.

BACKGROUND: Workers can be injured by animals such as mammals and insects. Previous studies found that most animal-related occupational fatalities were caused by horses and cattle. We analyzed characteristics of recent nonfatal severe animal-related injuries in US workers. METHODS: The severe injury reports (SIR) database, collected by the Occupational Safety and Health Administration, contains employer self-reports of inpatient hospitalizations and amputations. We used 2015-2021 SIR data to assess properties of animal-related injuries, including the type of animal involved, the nature of the injury, and the industry of the employer. Industry-specific incidence rates were calculated. RESULTS: We identified 788 severe animal-related injuries during the 7-year study period. Mammals caused over half of these injuries (476; 60.4%), followed by insects, arachnids, and mites (183; 23.2%) and reptiles (127; 16.1%). Two-thirds (529; 67.1%) of animal-related injuries were traumatic, while 211 (28.0%) injuries were due to poisoning or allergic reaction. The highest observed incidence was in livestock merchant wholesalers (59.6 severe injuries per 100,000 workers per year); injuries in this industry were often due to cattle. Mail delivery and landscape architecture, two industries in which animal contact is atypical, were also among the 10 industries with the highest incidence. CONCLUSIONS: Workers in many industries experienced severe injuries due to animals. Among workers whose job involves animal contact, cattle workers appear to be at highest risk. Outdoor workers in some industries require protection from bites of dogs, snakes, and insects.

Hospitalised heat-related acute kidney injury in indoor and outdoor workers in the USA.

OBJECTIVES: To characterise heat-related acute kidney injury (HR-AKI) among US workers in a range of industries. METHODS: Two data sources were analysed: archived case files of the Occupational Safety and Health Administration's (OSHA) Office of Occupational Medicine and Nursing from 2010 through 2020; and a Severe Injury Reports (SIR) database of work-related hospitalisations that employers reported to federal OSHA from 2015 to 2020. Confirmed, probable and possible cases of HR-AKI were ascertained by serum creatinine measurements and narrative incident descriptions. Industry-specific incidence rates of HR-AKI were computed. A capture-recapture analysis assessed under-reporting in SIR. RESULTS: There were 608 HR-AKI cases, including 22 confirmed cases and 586 probable or possible cases. HR-AKI occurred in indoor and outdoor industries including manufacturing, construction, mail and package delivery, and solid waste collection. Among confirmed cases, 95.2% were male, 50.0% had hypertension and 40.9% were newly hired workers. Incidence rates of AKI hospitalisations from 1.0 to 2.5 hours per 100 000 workers per year were observed in high-risk industries. Analysis of overlap between the data sources found that employers reported only 70.6% of eligible HR-AKI hospitalisations to OSHA, and only 41.2% of reports contained a consistent diagnosis. CONCLUSIONS: Workers were hospitalised with HR-AKI in diverse industries, including indoor facilities. Because of under-reporting and underascertainment, national surveillance databases underestimate the true burden of occupational HR-AKI. Clinicians should consider kidney risk from recurrent heat stress. Employers should provide interventions, such as comprehensive heat stress prevention programmes, that include acclimatisation protocols for new workers, to prevent HR-AKI.

Analysis of biomonitoring data to assess employer compliance with OSHA's permissible exposure limits for air contaminants.

BACKGROUND: The Occupational Safety and Health Administration (OSHA) regulates exposures to hazardous chemicals in workplace air. When contemporaneous exposure measurements are unavailable, retrospective analysis of biomarkers could provide valuable information about workers' exposures. METHODS: Single-compartment pharmacokinetic (PK) models were created to relate the concentration of a chemical in the air to the concentration of the chemical or its metabolite in workers' blood or urine. OSHA utilized the PK models in investigations of three fatal incidents in which workers were exposed to nickel carbonyl, methyl bromide, or styrene. To obtain the minimum plausible estimate of each exposure, OSHA used conservative assumptions about parameters such as workers' inhalation rates, baseline levels of biomarker, and chemicals' volumes of distribution. RESULTS: OSHA analyzed a worker's urinary nickel concentration and concluded that his 8-h time-weighted average exposure to nickel carbonyl was at least 0.06 mg/m3 . Analysis of a worker's postexposure, premortem blood bromide level revealed that his exposure to methyl bromide was at least 181 mg/m3 . Post-mortem blood styrene measurements suggested that a third worker's exposure to styrene was at least 625 mg/m3 . These exposures exceeded OSHA's permissible exposure limits of 0.007 mg/m3 for nickel carbonyl, 80 mg/m3 for methyl bromide, and 426 mg/m3 for styrene. OSHA successfully cited the three employers for violations of chemical exposure limits. CONCLUSIONS: Analysis of biomarkers via PK modeling enables retrospective evaluations of workers' acute exposures to hazardous chemicals. These techniques are useful to occupational regulators who assess employer compliance with mandatory exposure limits.

An outbreak of work-related asthma and silicosis at a US countertop manufacturing and fabrication facility.

BACKGROUND: Outbreaks of severe silicosis have affected workers who fabricate artificial stone countertops. Work-related asthma (WRA) has not been a prominent feature of those prior outbreaks. METHODS: This report describes an outbreak of WRA and silicosis at a facility that manufactures and fabricates chemical-resistant countertops comprised of sand, epoxy resin, and phthalic anhydride (PA), a known respiratory sensitizer. The multi-disciplinary investigation included clinical examinations of workers, an industrial hygiene survey with qualitative and quantitative exposure assessments, and a cross-sectional questionnaire. RESULTS: Engineering controls and personal protective equipment were inadequate. Some workers were exposed to PA or silica above permissible exposure limits established by the Occupational Safety and Health Administration (OSHA). Clinical and epidemiologic investigations identified 16 workers with confirmed or suspected WRA. Two years later, after OSHA began to enforce its new silica standards, 12 workers received medical surveillance for silicosis. Of these 12 workers, four (33.3%) were diagnosed with silicosis based on abnormal chest computed tomography examinations. CONCLUSIONS: Artificial stone countertop workers can develop asthma or silicosis. Risk of asthma may be highest in workers exposed to asthmagens such as PA and epoxy resins while manufacturing the artificial stone material.

A cluster of hypersensitivity pneumonitis associated with exposure to metalworking fluids.

BACKGROUND: Workers exposed to metalworking fluids (MWF) can develop respiratory illnesses including hypersensitivity pneumonitis (HP). These respiratory manifestations are likely due to microbial contamination of aerosolized MWF. This paper reports a cluster of HP and respiratory symptoms at a manufacturing plant where MWF and workplace air were contaminated with bacterial endotoxin despite frequent negative bacterial cultures of MWF. METHODS: A pulmonologist assessed and treated three workers with respiratory symptoms. The Occupational Safety and Health Administration (OSHA) inspected the plant. OSHA's investigation included bacterial culture of MWF, measurement of endotoxin concentrations in MWF and workplace air, review of the employer's fluid management program, and distribution of a cross-sectional symptom questionnaire. RESULTS: Three workers had biopsy-confirmed HP. In addition, 30.8% of questionnaire respondents reported work-related respiratory symptoms. OSHA detected endotoxin levels as high as 92,000 endotoxin units (EU)/ml in MWF and 3200 EU/m3 in air. Endotoxin concentrations and risk of MWF inhalation were highest near an unenclosed multistation computer numerical control machine. A contractor had tested this machine's MWF for bacterial growth weekly during the preceding three years, and most (96.0%) of those tests were negative. CONCLUSIONS: Contaminated MWF can cause severe occupational lung disease even if microorganisms do not grow in fluid cultures. Endotoxin testing can increase the sensitivity of detection of microbial contamination. However, employers should not rely solely upon MWF testing data to protect workers. Medical surveillance and meticulous source control, such as engineering controls to suppress MWF mist and prevent its inhalation, can reduce the likelihood of respiratory disease.

Actual and simulated weather data to evaluate wet bulb globe temperature and heat index as alerts for occupational heat-related illness.

Heat stress occupational exposure limits (OELs) were developed in the 1970s to prevent heat-related illnesses (HRIs). The OELs define the maximum safe wet bulb globe temperature (WBGT) for a given physical activity level. This study's objectives were to compute the sensitivity of heat stress OELs and determine if Heat Index could be a surrogate for WBGT. We performed a retrospective analysis of 234 outdoor work-related HRIs reported to the Occupational Safety and Health Administration in 2016. Archived NOAA weather data were used to compute each day's maximum WBGT and Heat Index. We defined the OELs' sensitivity as the percentage of incidents with WBGT > OEL. Sensitivity of the OELs was between 88% and 97%, depending upon our assumption about acclimatization status. In fatal cases, the OELs' sensitivity was somewhat higher (92-100%). We also computed the sensitivity of each possible Heat Index discrimination threshold. A Heat Index threshold of 80 °F (26.7 °C) was exceeded in 100% of fatalities and 99% of non-fatal HRIs. In a separate analysis, we created simulated weather data to assess associations of WBGT with Heat Index over a range of realistic outdoor heat conditions. These simulations demonstrated that for a given Heat Index, when radiant heat was included, WBGT was often higher than previously reported. The imperfect correlation between WBGT and Heat Index precluded a direct translation of OELs from WBGT into Heat Index. We conclude that WBGT-based heat stress exposure limits are highly sensitive and should be used for workplace heat hazard assessment. When WBGT is unavailable, a Heat Index alert threshold of approximately 80 °F (26.7 °C) could identify potentially hazardous workplace environmental heat.

Evaluation of Occupational Exposure Limits for Heat Stress in Outdoor Workers - United States, 2011-2016.

Heat stress, an environmental and occupational hazard, is associated with a spectrum of heat-related illnesses, including heat stroke, which can lead to death. CDC's National Institute for Occupational Safety and Health (NIOSH) publishes recommended occupational exposure limits for heat stress (1). These limits, which are consistent with those of the American Conference of Governmental Industrial Hygienists (ACGIH) (2), specify the maximum combination of environmental heat (measured as wet bulb globe temperature [WBGT]) and metabolic heat (i.e., workload) to which workers should be exposed. Exposure limits are lower for workers who are unacclimatized to heat, who wear work clothing that inhibits heat dissipation, and who have predisposing personal risk factors (1,2). These limits have been validated in experimental settings but not at outdoor worksites. To determine whether the NIOSH and ACGIH exposure limits are protective of workers, CDC retrospectively reviewed 25 outdoor occupational heat-related illnesses (14 fatal and 11 nonfatal) investigated by the Occupational Safety and Health Administration (OSHA) from 2011 to 2016. For each incident, OSHA assessed personal risk factors and estimated WBGT, workload, and acclimatization status. Heat stress exceeded exposure limits in all 14 fatalities and in eight of 11 nonfatal illnesses. An analysis of Heat Index data for the same 25 cases suggests that when WBGT is unavailable, a Heat Index screening threshold of 85°F (29.4°C) could identify potentially hazardous levels of workplace environmental heat. Protective measures should be implemented whenever the exposure limits are exceeded. The comprehensive heat-related illness prevention program should include an acclimatization schedule for newly hired workers and unacclimatized long-term workers (e.g., during early-season heat waves), training for workers and supervisors about symptom recognition and first aid (e.g., aggressive cooling of presumed heat stroke victims before medical professionals arrive), engineering and administrative controls to reduce heat stress, medical surveillance, and provision of fluids and shady areas for rest breaks.

The Heat Death Line: Proposed Heat Index Alert Threshold for Preventing Heat-Related Fatalities in the Civilian Workforce.

A threshold Heat Index (HI) can serve as the basis for advising the civilian workforce about the risk of heat-related illnesses. We conducted a systematic review and compiled reports of work-related fatalities from heat-related illnesses. We calculated the HI for each fatality. Our objective was to expand upon the military's concept of a "heat death line" and identify an HI alert threshold for the civilian workforce. We identified 14 publications totaling 570 heat-related deaths. In the meta-analysis, the median HI was 101 with a range of 62 to 137. Almost all deaths (96 percent and 99 percent of civilian and military fatalities, respectively) occurred when HI ≥80, which is our proposed heat death line. Some existing HI-based heat advisories are set at a higher temperature value. However, many occupational heat-related illnesses occur below these thresholds, resulting in low sensitivity and a false sense of security. In at-risk outdoor industries, HI ≥80 should trigger hazard awareness and protective actions.

Elucidating the Mechanism of Trypanosoma cruzi Acquisition by Triatomine Insects: Evidence from a Large Field Survey of Triatoma infestans.

Blood-sucking triatomine bugs transmit the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. We measured the prevalence of T. cruzi infection in 58,519 Triatoma infestans captured in residences in and near Arequipa, Peru. Among bugs from infected colonies, T. cruzi prevalence increased with stage from 12% in second instars to 36% in adults. Regression models demonstrated that the probability of parasite acquisition was roughly the same for each developmental stage. Prevalence increased by 5.9% with each additional stage. We postulate that the probability of acquiring the parasite may be related to the number of feeding events. Transmission of the parasite does not appear to be correlated with the amount of blood ingested during feeding. Similarly, other hypothesized transmission routes such as coprophagy fail to explain the observed pattern of prevalence. Our results could have implications for the feasibility of late-acting control strategies that preferentially kill older insects.

Occupational chemical exposures: a collaboration between the Georgia Poison Center and the Occupational Safety and Health Administration.

CONTEXT: In the United States, regional poison centers frequently receive calls about toxic workplace exposures. Most poison centers do not share call details routinely with governmental regulatory agencies. Worker health and safety could be enhanced if regulators such as the Occupational Safety and Health Administration (OSHA) had the ability to investigate these events and prevent similar incidents. With this goal in mind, the Georgia Poison Center (GPC) began referring occupational exposures to OSHA in July 2014. METHODS: GPC began collecting additional employer details when handling occupational exposure calls. When workers granted permission, GPC forwarded call details to the OSHA Regional Office in Atlanta. These referrals enabled OSHA to initiate several investigations. We also analyzed all occupational exposures reported to GPC during the study period to characterize the events, detect violations of OSHA reporting requirements, and identify hazardous scenarios that could form the basis for future OSHA rulemaking or guidance. RESULTS: GPC was informed about 953 occupational exposures between 1 July, 2014 and 7 January, 2016. Workers were exposed to 217 unique substances, and 70.3% of victims received treatment in a healthcare facility. Hydrogen sulfide was responsible for the largest number of severe clinical effects. GPC obtained permission to refer 89 (9.3%) calls to OSHA. As a result of these referrals, OSHA conducted 39 investigations and cited 15 employers for "serious" violations. OSHA forwarded several other referrals to other regulatory agencies when OSHA did not have jurisdiction. At least one employer failed to comply with OSHA's new rule that mandates reporting of all work-related hospitalizations. This collaboration increased OSHA's awareness of dangerous job tasks including hydrofluoric acid exposure among auto detailers and carbon monoxide poisoning with indoor use of gasoline-powered tools. CONCLUSIONS: Collaboration with the GPC generated a useful source of referrals to OSHA. OSHA investigations led to abatement of existing hazards, and OSHA acquired new knowledge of occupational exposure scenarios.

Risk Factors for Heat-Related Illness in U.S. Workers: An OSHA Case Series.

OBJECTIVE: The aim of this study was to describe risk factors for heat-related illness (HRI) in U.S. workers. METHODS: We reviewed a subset of HRI enforcement investigations conducted by the Occupational Safety and Health Administration (OSHA) from 2011 through 2016. We assessed characteristics of the workers, employers, and events. We stratified cases by severity to assess whether risk factors were more prevalent in fatal HRIs. RESULTS: We analyzed 38 investigations involving 66 HRIs. Many workers had predisposing medical conditions or used predisposing medications. Comorbidities were more prevalent in workers who died. Most (73%) fatal HRIs occurred during the first week on the job. Common clinical findings in heat stroke cases included multiorgan failure, muscle breakdown, and systemic inflammation. CONCLUSION: Severe HRI is more likely when personal susceptibilities coexist with work-related and environmental risk factors. Almost all HRIs occur when employers do not adhere to preventive guidelines.

Associations between Unconventional Natural Gas Development and Nasal and Sinus, Migraine Headache, and Fatigue Symptoms in Pennsylvania.

BACKGROUND: Unconventional natural gas development (UNGD) produces environmental contaminants and psychosocial stressors. Despite these concerns, few studies have evaluated the health effects of UNGD. OBJECTIVES: We investigated associations between UNGD activity and symptoms in a cross-sectional study in Pennsylvania. METHODS: We mailed a self-administered questionnaire to 23,700 adult patients of the Geisinger Clinic. Using standardized and validated questionnaire items, we identified respondents with chronic rhinosinusitis (CRS), migraine headache, and fatigue symptoms. We created a summary UNGD activity metric that incorporated well phase, location, total depth, daily gas production and inverse distance-squared to patient residences. We used logistic regression, weighted for sampling and response rates, to assess associations between quartiles of UNGD activity and outcomes, both alone and in combination. RESULTS: The response rate was 33%. Of 7,785 study participants, 1,850 (24%) had current CRS symptoms, 1,765 (23%) had migraine headache, and 1,930 (25%) had higher levels of fatigue. Among individuals who met criteria for two or more outcomes, adjusted odds ratios for the highest quartile of UNGD activity compared with the lowest were [OR (95% CI)] 1.49 (0.78, 2.85) for CRS plus migraine, 1.88 (1.08, 3.25) for CRS plus fatigue, 1.95 (1.18, 3.21) for migraine plus fatigue, and 1.84 (1.08, 3.14) for all three outcomes together. Significant associations were also present in some models of single outcomes. CONCLUSIONS: This study provides evidence that UNGD is associated with nasal and sinus, migraine headache, and fatigue symptoms in a general population representative sample. Citation: Tustin AW, Hirsch AG, Rasmussen SG, Casey JA, Bandeen-Roche K, Schwartz BS. 2017. Associations between unconventional natural gas development and nasal and sinus, migraine headache, and fatigue symptoms in Pennsylvania. Environ Health Perspect 125:189-197; http://dx.doi.org/10.1289/EHP281.

Bed bugs (Cimex lectularius) as vectors of Trypanosoma cruzi.

Populations of the common bed bug, Cimex lectularius, have recently undergone explosive growth. Bed bugs share many important traits with triatomine insects, but it remains unclear whether these similarities include the ability to transmit Trypanosoma cruzi, the etiologic agent of Chagas disease. Here, we show efficient and bidirectional transmission of T. cruzi between hosts and bed bugs in a laboratory environment. Most bed bugs that fed on experimentally infected mice acquired the parasite. A majority of previously uninfected mice became infected after a period of cohabitation with exposed bed bugs. T. cruzi was also transmitted to mice after the feces of infected bed bugs were applied directly to broken host skin. Quantitative bed bug defecation measures were similar to those of important triatomine vectors. Our findings suggest that the common bed bug may be a competent vector of T. cruzi and could pose a risk for vector-borne transmission of Chagas disease.

Use of Individual-level Covariates to Improve Latent Class Analysis of Trypanosoma Cruzi Diagnostic Tests.

Statistical methods such as latent class analysis can estimate the sensitivity and specificity of diagnostic tests when no perfect reference test exists. Traditional latent class methods assume a constant disease prevalence in one or more tested populations. When the risk of disease varies in a known way, these models fail to take advantage of additional information that can be obtained by measuring risk factors at the level of the individual. We show that by incorporating complex field-based epidemiologic data, in which the disease prevalence varies as a continuous function of individual-level covariates, our model produces more accurate sensitivity and specificity estimates than previous methods. We apply this technique to a simulated population and to actual Chagas disease test data from a community near Arequipa, Peru. Results from our model estimate that the first-line enzyme-linked immunosorbent assay has a sensitivity of 78% (95% CI: 62-100%) and a specificity of 100% (95% CI: 99-100%). The confirmatory immunofluorescence assay is estimated to be 73% sensitive (95% CI: 65-81%) and 99% specific (95% CI: 96-100%).

A history of chagas disease transmission, control, and re-emergence in peri-rural La Joya, Peru.

BACKGROUND: The history of Chagas disease control in Peru and many other nations is marked by scattered and poorly documented vector control campaigns. The complexities of human migration and sporadic control campaigns complicate evaluation of the burden of Chagas disease and dynamics of Trypanosoma cruzi transmission. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional serological and entomological study to evaluate temporal and spatial patterns of T. cruzi transmission in a peri-rural region of La Joya, Peru. We use a multivariate catalytic model and Bayesian methods to estimate incidence of infection over time and thereby elucidate the complex history of transmission in the area. Of 1,333 study participants, 101 (7.6%; 95% CI: 6.2-9.0%) were confirmed T. cruzi seropositive. Spatial clustering of parasitic infection was found in vector insects, but not in human cases. Expanded catalytic models suggest that transmission was interrupted in the study area in 1996 (95% credible interval: 1991-2000), with a resultant decline in the average annual incidence of infection from 0.9% (95% credible interval: 0.6-1.3%) to 0.1% (95% credible interval: 0.005-0.3%). Through a search of archival newspaper reports, we uncovered documentation of a 1995 vector control campaign, and thereby independently validated the model estimates. CONCLUSIONS/SIGNIFICANCE: High levels of T. cruzi transmission had been ongoing in peri-rural La Joya prior to interruption of parasite transmission through a little-documented vector control campaign in 1995. Despite the efficacy of the 1995 control campaign, T. cruzi was rapidly reemerging in vector populations in La Joya, emphasizing the need for continuing surveillance and control at the rural-urban interface.