Workers in electronics waste and lamp recycling facilities are at risk of exposure to elemental mercury through inhalation of mercury vapor and mercury-containing dust. Employers at an electronics waste and lamp recycling facility in Ohio that crushes mercury-containing lamps expressed concerns about mercury exposure from work processes and requested a health hazard evaluation by CDC's National Institute for Occupational Safety and Health (NIOSH). In April 2023, NIOSH conducted a multidisciplinary investigation to assess elemental and inorganic mercury exposures, including epidemiologic, environmental, and ventilation assessments. Results indicated that mercury vapor was detected throughout the facility, with six of 14 workers having elevated urine mercury levels. These workers had a median job tenure of 8 months; four did not speak English, and five reported symptoms consistent with mercury toxicity, such as metallic or bitter taste, difficulty thinking, and changes in personality. Recommendations included improving the ventilation system, changing work practices to reduce mercury exposure, and providing training and communication tailored to the worker. As the electronic waste recycling industry continues to grow, it is important for employers to evaluate mercury exposure and safeguard employees using a hierarchy of controls. Health departments should consider monitoring occupational mercury exposure in recycling facilities, and clinicians should be aware of the potential for mercury toxicity among workers in these settings.

Responses to complaints about low-frequency noise and infrasound at workplaces have not been extensively documented in the literature. The National Institute for Occupational Safety and Health evaluated low-frequency noise, infrasound, and health symptoms among employees of an organization providing services to homeless persons. The organization's campus was evacuated after two loud noise and vibration incidents related to methane flare on an adjacent landfill. Employees were interviewed about health symptoms, perceptions of noise, and how the incidents were handled. Available medical records were reviewed. Sound level and noise frequency measurements taken in vacated campus buildings not during these incidents revealed overall levels across frequencies up to 100 hertz were 64 to 73 dB, well below those associated with adverse health effects. However, an unbalanced frequency spectrum could have contributed to the unusual sounds or vibrations reported before the first incident. Some symptoms predating the incidents are consistent with low-frequency noise exposure but are also common and nonspecific. Most interviewed employees (57%) reported being uncomfortable returning to work on the campus. Multiple factors such as noise characteristics, health effects, and employee perceptions need to be considered when assessing health concerns related to low-frequency noise and infrasound.

Wildland firefighters (WFFs) are exposed to many inhalation hazards working in the wildland fire environment. To assess occupational exposures and acute and subacute health effects among WFFs, the wildland firefighter exposure and health effects study collected data for a 2-year repeated measures study. This manuscript describes the exposure assessment from one Interagency Hotshot Crew (N = 19) conducted at a wildfire incident. Exposures to benzene, toluene, ethylbenzene, xylene isomers, formaldehyde, acetaldehyde, and naphthalene were measured through personal air sampling each work shift. Biological monitoring was done for creatinine-adjusted levoglucosan in urine pre- and post-shift. For 3 days sampling at the wildfire incident, benzene, toluene, ethylbenzene, xylene isomers (m and p, and o) exposure was highest on day 1 (geometric mean [GM] = 0.015, 0.042, 0.10, 0.42, and 0.15 ppm, respectively) when WFFs were not exposed to smoke but used chainsaws to remove vegetation and prepare fire suppression breaks. Exposure to formaldehyde and acetaldehyde was highest on day 2 (GM = 0.03 and 0.036 ppm, respectively) when the WFFs conducted a firing operation and were directly exposed to wildfire smoke. The greatest difference of pre- and post-shift levoglucosan concentrations were observed on day 3 (pre-shift: 9.7 and post-shift: 47 μg/mg creatinine) after WFFs conducted mop up (returned to partially burned area to extinguish any smoldering vegetation). Overall, 65% of paired samples (across all sample days) showed a post-shift increase in urinary levoglucosan and 5 firefighters were exposed to benzene at concentrations at or above the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit. Our findings further demonstrate that exposure to inhalation hazards is one of many risks that wildland firefighters experience while suppressing wildfires.

The National Institute for Occupational Safety and Health (NIOSH) evaluated continuous and impact noise exposures and hearing loss among workers at a hammer forge company. Full-shift personal noise exposure measurements were collected on forge workers across 15 different job titles; impact noise characteristics and one-third octave band noise levels were assessed at the forge hammers; and 4,750 historic audiometric test records for 483 workers were evaluated for hearing loss trends. Nearly all workers' noise exposures exceeded regulatory and/or recommended exposure limits. Workers working in jobs at or near the hammers had full-shift time-weighted average noise exposures above 100 decibels, A-weighted. Impact noise at the hammers reached up to 148 decibels. Analysis of audiometric test records showed that 82% of workers had experienced a significant threshold shift, as defined by NIOSH, and 63% had experienced a standard threshold shift, as defined by the Occupational Safety and Health Administration (OSHA). All workers with an OSHA standard threshold shift had a preceding NIOSH significant threshold shift which occurred, on average, about 7 years prior. This evaluation highlights forge workers' exposures to high levels of noise, including impact noise, and how their hearing worsened with age and length of employment. © 2023. Thieme. All rights reserved. Thieme Medical Publishers, Inc.

The primary objective of this work was to characterize employee exposure to radon and progeny while performing guide/interpretation and concessions duties in a tourist cavern. Radon gas and progeny concentrations, fraction of unattached progeny, and other environmental parameters were evaluated in a popular tourist cavern in Southeastern New Mexico. Alpha-track detectors were used to measure radon gas in several cavern locations during a 9-mo period. Additionally, radon gas and attached and unattached fractions of radon progeny were measured at three primary cavern work locations during a 1-d period using a SARAD EQF 3220. Radon gas concentrations in the cavern were elevated due to extremely low air exchange rates with substantial seasonal variation. Mean measured radon concentrations ranged from 970 to 2,600 Bq m-3 in the main cavern and from 5,400 to 6,000 Bq m-3 in a smaller cave associated with the regional cave system. Measurements of unattached fractions (0.40-0.60) were higher than those commonly found in mines and other workplaces, leading to the potential for relatively high worker dose. Although radon gas concentrations were below the Occupational Safety and Health Administration Permissible Exposure Limit, employees working in the cavern have the potential to accrue ionizing radiation dose in excess of the annual effective dose limit recommended by the National Council on Radiation Protection and Measurements due to a high unattached fraction of radon progeny. There was a strong negative correlation between unattached fractions and equilibrium factors, but these parameters should be further evaluated for seasonal variation. Introduction of engineering controls such as ventilation could damage the cavern environment, so administrative controls, such as time management, are preferred to reduce employee dose.

INTRODUCTION: Healthcare personnel are at high risk for exposure to influenza by direct and indirect contact, droplets and aerosols, and by aerosol generating procedures. Information on air and surface influenza contamination is needed to assist in developing guidance for proper prevention and control strategies. To understand the vulnerabilities of healthcare personnel, we measured influenza in the breathing zone of healthcare personnel, in air and on surfaces within a healthcare setting, and on filtering facepiece respirators worn by healthcare personnel when conducting patient care. METHODS: Thirty participants were recruited from an adult emergency department during the 2015 influenza season. Participants wore personal bioaerosol samplers for six hours of their work shift, submitted used filtering facepiece respirators and medical masks and completed questionnaires to assess frequency and types of interactions with potentially infected patients. Room air samples were collected using bioaerosol samplers, and surface swabs were collected from high-contact surfaces within the adult emergency department. Personal and room bioaerosol samples, surface swabs, and filtering facepiece respirators were analyzed for influenza A by polymerase chain reaction. RESULTS: Influenza was identified in 42% (53/125) of personal bioaerosol samples, 43% (28/ 96) of room bioaerosol samples, 76% (23/30) of pooled surface samples, and 25% (3/12) of the filtering facepiece respirators analyzed. Influenza copy numbers were greater in personal bioaerosol samples (17 to 631 copies) compared to room bioaerosol samples (16 to 323 copies). Regression analysis suggested that the amount of influenza in personal samples was approximately 2.3 times the amount in room samples (Wald chi2 = 16.21, p<0.001). CONCLUSIONS: Healthcare personnel may encounter increased concentrations of influenza virus when in close proximity to patients. Occupations that require contact with patients are at an increased risk for influenza exposure, which may occur throughout the influenza season. Filtering facepiece respirators may become contaminated with influenza when used during patient care.

Increased understanding of influenza transmission is critical for pandemic planning and selecting appropriate controls for healthcare personnel safety and health. The goals of this pilot study were to assess environmental contamination in different areas and at two time periods in the influenza season and to determine the feasibility of using surgical mask contamination to evaluate potential exposure to influenza virus. Bioaerosol samples were collected over 12 days (two 6-day sessions) at 12 locations within a student health center using portable two-stage bioaerosol samplers operating 8 hours each day. Surface samples were collected each morning and afternoon from common high-contact non-porous hard surfaces from rooms and locations where bioaerosol samplers were located. Surgical masks worn by participants while in contact with patients with influenza-like illness were collected. A questionnaire administered to each of the 12 participants at the end of each workday and another at the end of each workweek assessed influenza-like illness symptoms, estimated the number of influenza-like illness patient contacts, hand hygiene, and surgical mask usage. All samples were analyzed using qPCR. Over the 12 days of the study, three of the 127 (2.4%) bioaerosol samples, two of 483 (0.41%) surface samples, and zero of 54 surgical masks were positive for influenza virus. For the duration of contact that occurred with an influenza patient on any of the 12 days, nurse practitioners and physicians reported contacts with influenza-like illness patients > 60 minutes, medical assistants reported 15-44 minutes, and administrative staff reported < 30 minutes. Given the limited number of bioaerosol and surface samples positive for influenza virus in the bioaerosol and surface samples, the absence of influenza virus on the surgical masks provides inconclusive evidence for the potential to use surgical masks to assess exposure to influenza viruses. Further studies are needed to determine feasibility of this approach in assessing healthcare personnel exposures. Information learned in this study can inform future field studies on influenza transmission.

An aircraft seat manufacturing company requested a NIOSH health hazard evaluation to help identify a strong odor that had persisted throughout the facility for over a year. Employees reported experiencing health effects thought to be related to the odor. We collected and analyzed area air samples for volatile organic compounds, endotoxin, bacterial and fungal metagenome, and metalworking fluid aerosol. Bulk metalworking fluid samples were analyzed for endotoxin, bacterial and fungal metagenome, and viable bacteria and fungus. We also evaluated the building ventilation systems and water diversion systems. Employees underwent confidential medical interviews about work practices, medical history, and health concerns. Based on our analyses, the odor was likely 2-methoxy-3,5-dimethylpyrazine. This pyrazine was found in air samples across the facility and originated from bacteria in the metalworking fluid. We did not identify bacteria known to produce the compound but bacteria from the same Proteobacteria order were found as well as bacteria from orders known to produce other pyrazines. Chemical and biological contaminants and odors could have contributed to health symptoms reported by employees, but it is likely that the symptoms were caused by several factors. We provided several recommendations to eliminate the odor including washing and disinfecting the metalworking machines and metalworking fluid recycling equipment, discarding all used metalworking fluid, instituting a metalworking fluid maintenance program at the site, and physically isolating the metalworking department from other departments.

Closed-face 37-millimeter (mm) polystyrene cassettes are often used for exposure monitoring of metal particulates. Several methods have been proposed to account for the wall loss in air sampling cassettes, including rinsing, wiping, within-cassette dissolution, and an internal capsule fused to the filter that could be digested with the filter. Until internal capsules replace filters, other methods for assessing wall losses may be considered. To determine if rinsing and wiping or wiping alone is adequate to determine wall losses on cassettes, we collected 54 full-shift area air samples at a battery recycling facility. We collected six replicate samples at three locations within the facility for 3 consecutive days. The wall losses of three replicate cassettes from each day-location were analyzed following a rinse and two consecutive wipes. The wall losses of the other three replicates from each day-location were analyzed following two consecutive wipes only. Mixed-cellulose ester membrane filter, rinse, and wipes were analyzed separately following NIOSH Method 7303. We found an average of 29% (range: 8%-54%) recovered lead from the cassette walls for all samples. We also found that rinsing prior to wiping the interior cassette walls did not substantially improve recovery of wall losses compared to wiping alone. A rinse plus one wipe recovered on average 23% (range: 13%-33%) of the lead, while one wipe alone recovered on average 21% (range: 16%-22%). Similarly we determined that a second wipe did not provide substantial additional recovery of lead (average: 4%, range: 0.4%-19%) compared to the first wipe disregarding the rinse (average: 18%, range: 4%-39%). We concluded that when an internal capsule is not used, wall losses of lead dust in air sampling cassettes can be adequately recovered by wiping the internal wall surfaces of the cassette with a single wipe.

BACKGROUND: Influenza can spread among students, teachers, and staff in school settings. Vaccination is the most effective method to prevent influenza. We determined 2012-2013 influenza vaccination coverage among school employees, assessed knowledge and attitudes regarding the vaccine, and determined factors associated with vaccine receipt. METHODS: We surveyed 412 (49%) of 841 employees at 1 suburban Ohio school district in March 2013. The Web-based survey assessed personal and work characteristics, vaccine receipt, and knowledge and attitudes regarding the vaccine. RESULTS: Overall, 238 (58%) respondents reported getting the 2012-2013 influenza vaccine. The most common reason for getting the vaccine was to protect oneself or one's family (87%). Beliefs that the vaccine was not needed (32%) or that it was not effective (21%) were the most common reasons for not getting it. Factors independently associated with vaccine receipt were having positive attitudes toward the vaccine, feeling external pressure to get it, and feeling personal control over whether to get it. CONCLUSIONS: Influenza vaccine coverage among school employees should be improved. Messages encouraging school employees to get the vaccine should address misconceptions about the vaccine. Employers should use methods to maximize employee vaccination as part of a comprehensive influenza prevention program.

We determined the prevalence of influenza-like illness (ILI) among employees of a suburban Ohio school district. In a survey of 412 of 841 employees (49%), 120 (29%) reported ILI symptoms during the school year, and 92 (77%) reported working while ill. Age ≥50 years and asthma were significantly associated with reporting of ILI symptoms. Encouraging school employees to receive the seasonal influenza vaccine and to stay home when ill should be part of a comprehensive influenza prevention strategy.

This study used a task-based approach to reconstruct employee noise exposures at two large automotive manufacturing plants for the period 1970-1989, utilizing historic noise measurement data, work history records, documented changes in plant operations, focus group discussions, structured interviews with long-tenure employees, and task-based job profiles. Task-based job noise exposure profiles were developed in the 1990s when the plants conducted task-based noise monitoring. Under the assumption that tasks and time-at-task profile within jobs did not change over time, these profiles were applied to historic jobs. By linking historic noise exposure measurements to job tasks, this approach allowed task-based reconstructed noise exposure profiles to capture variability of daily noise exposures. Reconstructed noise exposures, along with task-based noise exposure measurements collected at each plant during the 1990s, were analyzed to examine time trends in workplace noise levels and worker noise exposure. Our analysis of noise exposure trends revealed that noise levels for many jobs declined by ≥3 dBA from 1970 to 1998 as operational and equipment changes occurred in the plants and some noise control measures were implemented, but for some jobs, noise levels increased in the mid- to late 1990s, most likely because of an increase in production at that time. Overall, the percentage of workers exposed to noise levels >90 dBA decreased from 95% in 1970 to 54% in 1998 at one of the plants and decreased from 36% in 1970 to ~5% in 1999 at the other plant. These reductions indicate a degree of success for the hearing conservation program. However, the actual number of employees with noise exposure >90 dBA increased because of a substantial increase in the number of production employees, particularly in jobs with high noise levels, which shows a hearing conservation program challenge that companies face during periods of increased production. Future analysis of hearing levels in these plant populations will help determine whether noise level reduction translates into decreased hearing loss at these plants.

BACKGROUND: A cluster of influenza-like illness (ILI) among physicians in training during the 2009 influenza A (H1N1) pandemic (pH1N1) led to a health hazard evaluation. METHODS: We conducted a cross-sectional study to examine exposures, infection control practices, ILI prevalence, and transmission among physicians in training at 4 affiliated hospitals during the pandemic. We administered an electronic survey and met with physicians in training and hospital personnel. RESULTS: Of the 88 responding physicians, 85% reported exposure to pH1N1. Exposures occurred at work from patients or coworkers and outside of work from coworkers, household members, or the community. Thirteen cases of ILI were reported in May-June 2009; 10 respondents reported working while ill (duration, 1-4 days). Between 13% and 88% of respondents knew which personal protective equipment (PPE) was recommended when caring for influenza patients at the 4 hospitals. The most common reasons for not using PPE were not knowing that a patient had pH1N1 or ILI and not having PPE readily available. CONCLUSIONS: Physicians in training have gaps in their knowledge of and adherence to recommended PPE and compliance with work restrictions. Our findings underscore the importance of installing isolation precaution signage, making PPE readily available near patients with influenza, and facilitating work restrictions for ill health care personnel.

OBJECTIVES: To evaluate the effectiveness of hearing conservation programs (HCP) and their specific components in reducing noise-induced hearing loss (NIHL). METHODS: This retrospective cohort study was conducted at one food-processing plant and two automotive plants. Audiometric and work-history databases were combined with historical noise monitoring data to develop a time-dependent exposure matrix for each plant. Historical changes in production and HCP implementation were collected from company records, employee interviews and focus groups. These data were used to develop time-dependent quality assessments for various HCP components. 5478 male (30 427 observations) and 1005 female (5816 observations) subjects were included in the analysis. RESULTS: Analyses were conducted separately for males and females. Females tended to have less NIHL at given exposure levels than males. Duration of noise exposure stratified by intensity (dBA) was a better predictor of NIHL than the standard equivalent continuous noise level (L(eq)) based upon a 3-dBA exchange. Within this cohort, efficient dBA strata for males were <95 versus ≥95, and for females <90 versus ≥90. The reported enforced use of hearing protection devices (HPDs) significantly reduced NIHL. The data did not have sufficient within-plant variation to determine the effectiveness of noise monitoring or worker training. An association between increased audiometric testing and NIHL was believed to be an artifact of increased participation in screening. CONCLUSIONS: Historical audiometric data combined with noise monitoring data can be used to better understand the effectiveness of HCPs. Regular collection and maintenance of quality data should be encouraged and used to monitor the effectiveness of these interventions.

BACKGROUND: In October 2007, a cluster of patients experiencing a novel polyradiculoneuropathy was identified at a pork abattoir (Plant A). Patients worked in the primary carcass processing area (warm room); the majority processed severed heads (head-table). An investigation was initiated to determine risk factors for illness. METHODS AND RESULTS: Symptoms of the reported patients were unlike previously described occupational associated illnesses. A case-control study was conducted at Plant A. A case was defined as evidence of symptoms of peripheral neuropathy and compatible electrodiagnostic testing in a pork abattoir worker. Two control groups were used - randomly selected non-ill warm-room workers (n = 49), and all non-ill head-table workers (n = 56). Consenting cases and controls were interviewed and blood and throat swabs were collected. The 26 largest U.S. pork abattoirs were surveyed to identify additional cases. Fifteen cases were identified at Plant A; illness onsets occurred during May 2004-November 2007. Median age was 32 years (range, 21-55 years). Cases were more likely than warm-room controls to have ever worked at the head-table (adjusted odds ratio [AOR], 6.6; 95% confidence interval [CI], 1.6-26.7), removed brains or removed muscle from the backs of heads (AOR, 10.3; 95% CI, 1.5-68.5), and worked within 0-10 feet of the brain removal operation (AOR, 9.9; 95% CI, 1.2-80.0). Associations remained when comparing head-table cases and head-table controls. Workers removed brains by using compressed air that liquefied brain and generated aerosolized droplets, exposing themselves and nearby workers. Eight additional cases were identified in the only two other abattoirs using this technique. The three abattoirs that used this technique have stopped brain removal, and no new cases have been reported after 24 months of follow up. Cases compared to controls had higher median interferon-gamma (IFNgamma) levels (21.7 pg/ml; vs 14.8 pg/ml, P<0.001). DISCUSSION: This novel polyradiculoneuropathy was associated with removing porcine brains with compressed air. An autoimmune mechanism is supported by higher levels of IFNgamma in cases than in controls consistent with other immune mediated illnesses occurring in association with neural tissue exposure. Abattoirs should not use compressed air to remove brains and should avoid procedures that aerosolize CNS tissue. This outbreak highlights the potential for respiratory or mucosal exposure to cause an immune-mediated illness in an occupational setting.