SARS-CoV-2 outbreak among staff and evacuees at Operation Allies Welcome Safe Havens.

We report on five SARS-CoV-2 congregate setting outbreaks at U.S. Operation Allies Welcome Safe Havens/military facilities. Outbreak data were collected, and attack rates were calculated for various populations. Even in vaccinated populations, there was rapid spread, illustrating the importance of institutional prevention and mitigation policies in congregate settings.

Assessing occupational erionite and respirable crystalline silica exposure among outdoor workers in Wyoming, South Dakota, and Montana.

Erionite is a naturally occurring fibrous mineral found in many parts of the world, including the western United States. Inhalational exposure to erionite fibers in some localities is associated with health effects similar to those caused by asbestos exposure, including malignant mesothelioma. Therefore, there is concern regarding occupational exposures in the western United States. Currently, there are no standard sampling and analytical methods for airborne erionite fibers, as well as no established occupational exposure limits. Due to the potential adverse health effects, characterizing and minimizing exposures is prudent. Crystalline silica also occurs naturally in areas where erionite is found, principally as the mineral quartz. Work activities involving rocks containing quartz and soils derived from those rocks can lead to exposure to respirable crystalline silica (RCS). The typically dry and dusty environment of the western United States can increase the likelihood of exposures to aerosolized rocks and soils, but inhalation exposure is also possible in more humid conditions. In this case study, we describe several outdoor occupational environments with potential exposures to erionite and RCS. We describe our method for evaluating those exposures and demonstrate: (1) the occurrence of occupational exposures to airborne erionite and RCS, (2) that the chemical make-up of the erionite mineral can be determined, and (3) that effective dust control practices are needed to reduce employee exposures to these minerals.

Metal Exposures at three U.S. electronic scrap recycling facilities.

Many metals found in electronic scrap are known to cause serious health effects, including but not limited to cancer and respiratory, neurologic, renal, and reproductive damage. The National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention performed three health hazard evaluations at electronic scrap recycling facilities in the U.S. to characterize employee exposure to metals and recommend control strategies to reduce these exposures. We performed air, surface, and biological monitoring for metals. We found one overexposure to lead and two overexposures to cadmium. We found metals on non-production surfaces, and the skin and clothing of workers before they left work in all of the facilities. We also found some elevated blood lead levels (above 10 micrograms per deciliter), however no employees at any facility had detectable mercury in their urine or exceeded 34% of the OELs for blood or urine cadmium. This article focuses on sampling results for lead, cadmium, mercury, and indium. We provided recommendations for improving local exhaust ventilation, reducing the recirculation of potentially contaminated air, using respirators until exposures are controlled, and reducing the migration of contaminants from production to non-production areas. We also recommended ways for employees to prevent taking home metal dust by using work uniforms laundered on-site, storing personal and work items in separate lockers, and using washing facilities equipped with lead-removing cleaning products.

Lessons learned from surface wipe sampling for lead in three workplaces.

Surface wipe sampling in the occupational environment is a technique widely used by industrial hygienists. Although several organizations have promulgated standards for sampling lead and other metals, uncertainty still exists when trying to determine an appropriate wipe sampling strategy and how to interpret sampling results. Investigators from the National Institute for Occupational Safety and Health (NIOSH) Health Hazard Evaluation Program have used surface wipe sampling as part of their exposure assessment sampling strategies in a wide range of workplaces. This article discusses wipe sampling for measuring lead on surfaces in three facilities: (1) a battery recycling facility; (2) a firing range and gun store; and (3) an electronic scrap recycling facility. We summarize our findings from the facilities and what we learned by integrating wipe sampling into our sampling plan. Wiping sampling demonstrated lead in non-production surfaces in all three workplaces and that the potential that employees were taking lead home to their families existed. We also found that the presence of metals such as tin can interfere with the colorimetric results. We also discuss the advantages and disadvantages of colorimetric analysis of surface wipe samples and the challenges we faced when interpreting wipe sampling results.

NIOSH field studies team assessment: Worker exposure to aerosolized metal oxide nanoparticles in a semiconductor fabrication facility.

The ubiquitous use of engineered nanomaterials-particulate materials measuring approximately 1-100 nanometers (nm) on their smallest axis, intentionally engineered to express novel properties-in semiconductor fabrication poses unique issues for protecting worker health and safety. Use of new substances or substances in a new form may present hazards that have yet to be characterized for their acute or chronic health effects. Uncharacterized or emerging occupational health hazards may exist when there is insufficient validated hazard data available to make a decision on potential hazard and risk to exposed workers under condition of use. To advance the knowledge of potential worker exposure to engineered nanomaterials, the National Institute for Occupational Safety and Health Nanotechnology Field Studies Team conducted an on-site field evaluation in collaboration with on-site researchers at a semiconductor research and development facility on April 18-21, 2011. The Nanomaterial Exposure Assessment Technique (2.0) was used to perform a complete exposure assessment. A combination of filter-based sampling and direct-reading instruments was used to identify, characterize, and quantify the potential for worker inhalation exposure to airborne alumina and amorphous silica nanoparticles associated with th e chemical mechanical planarization wafer polishing process. Engineering controls and work practices were evaluated to characterize tasks that might contribute to potential exposures and to assess existing engineering controls. Metal oxide structures were identified in all sampling areas, as individual nanoparticles and agglomerates ranging in size from 60 nm to >1,000 nm, with varying structure morphology, from long and narrow to compact. Filter-based samples indicated very little aerosolized material in task areas or worker breathing zone. Direct-reading instrument data indicated increased particle counts relative to background in the wastewater treatment area; however, particle counts were very low overall, indicating a well-controlled working environment. Recommendations for employees handling or potentially exposed to engineered nanomaterials include hazard communication, standard operating procedures, conservative ventilation systems, and prevention through design in locations where engineered nanomaterials are used or stored, and routine air sampling for occupational exposure assessment and analysis.

Refinement of the Nanoparticle Emission Assessment Technique into the Nanomaterial Exposure Assessment Technique (NEAT 2.0).

Engineered nanomaterial emission and exposure characterization studies have been completed at more than 60 different facilities by the National Institute for Occupational Safety and Health (NIOSH). These experiences have provided NIOSH the opportunity to refine an earlier published technique, the Nanoparticle Emission Assessment Technique (NEAT 1.0), into a more comprehensive technique for assessing worker and workplace exposures to engineered nanomaterials. This change is reflected in the new name Nanomaterial Exposure Assessment Technique (NEAT 2.0) which distinguishes it from NEAT 1.0. NEAT 2.0 places a stronger emphasis on time-integrated, filter-based sampling (i.e., elemental mass analysis and particle morphology) in the worker's breathing zone (full shift and task specific) and area samples to develop job exposure matrices. NEAT 2.0 includes a comprehensive assessment of emissions at processes and job tasks, using direct-reading instruments (i.e., particle counters) in data-logging mode to better understand peak emission periods. Evaluation of worker practices, ventilation efficacy, and other engineering exposure control systems and risk management strategies serve to allow for a comprehensive exposure assessment.

Comparison of a Wipe Method With and Without a Rinse to Recover Wall Losses in Closed Face 37-mm Cassettes used for Sampling Lead Dust Particulates.

Closed-face 37-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 three 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.

Indoor firing ranges and elevated blood lead levels - United States, 2002-2013.

Indoor firing ranges are a source of lead exposure and elevated blood lead levels (BLLs) among employees, their families, and customers, despite public health outreach efforts and comprehensive guidelines for controlling occupational lead exposure. There are approximately 16,000-18,000 indoor firing ranges in the United States, with tens of thousands of employees. Approximately 1 million law enforcement officers train on indoor ranges. To estimate how many adults had elevated BLLs (≥10 µg/dL) as a result of exposure to lead from shooting firearms, data on elevated BLLs from the Adult Blood Lead Epidemiology and Surveillance (ABLES) program managed by CDC's National Institute for Occupational Safety and Health (NIOSH) were examined by source of lead exposure. During 2002-2012, a total of 2,056 persons employed in the categories "police protection" and "other amusement and recreation industries (including firing ranges)" had elevated BLLs reported to ABLES; an additional 2,673 persons had non-work-related BLLs likely attributable to target shooting. To identify deficiencies at two indoor firing ranges linked to elevated BLLs, the Washington State Division of Occupational Safety and Health (WaDOSH) and NIOSH conducted investigations in 2012 and 2013, respectively. The WaDOSH investigation found a failure to conduct personal exposure and biologic monitoring for lead and also found dry sweeping of lead-containing dust. The NIOSH investigation found serious deficiencies in ventilation, housekeeping, and medical surveillance. Public health officials and clinicians should ask about occupations and hobbies that might involve lead when evaluating findings of elevated BLLs. Interventions for reducing lead exposure in firing ranges include using lead-free bullets, improving ventilation, and using wet mopping or high-efficiency particulate air (HEPA) vacuuming to clean.

Expanding control banding for workplace silica exposures throughout the Americas.

BACKGROUND: Silicosis, a lung disease caused by inhaling respirable crystalline silica dust, is an occupational illness affecting millions of workers worldwide. The National Institute for Occupational Safety and Health (NIOSH) has partnered with the World Health Organization, the International Labour Organization, and multiple agencies in the Americas to implement the program "The Elimination of Silicosis in the Americas". OBJECTIVES: One component of this program is control banding, a qualitative risk assessment and management strategy that allows non-experts to use task-based hazard data and potential exposure information to determine appropriate controls. RESULTS: From 2005 to the present, NIOSH occupational health researchers have worked with experts in Chile, Peru, Colombia, and Brazil to assess, implement, and provide tools to evaluate the use of control banding methodology.

Field evaluation of sequential hand wipes for flame retardant exposure in an electronics recycling facility.

Flame retardants have been associated with endocrine disorders, thyroid disruption, reproductive toxicity, and immunological interference. Through dismantling and recycling electronics and electric products, flame retardants can be released into the air and settle on work surfaces which may lead to dermal exposure. Hand wipe sampling is commonly used to evaluate dermal exposure. This study assesses the removal efficiency of wipes on the hands of recycling employees, and to compare the efficacy of two common surface wipe sampling materials. We used three sequential hand wipes and quantified the percentage of flame retardants that was removed by each hand wipe in the sequence. Two common wipe materials (gauze and twill) were used to compare the ability to remove flame retardants. The wipes were collected from 12 employees at a U.S. electronics recycling facility immediately at the end of their shift, prior to washing their hands. Results show that although the first wipe removed the highest median percent of the sum of the three wipes for most flame retardants, there was a wide range of the percentages of total individual flame retardants removed by both gauze (4%-98%) or twill hand wipe (1%-89%). Approximately half of the flame retardants a high percentage (>50%) removed by the second and third wipes. This suggests that a single wipe is not sufficient to characterize the extent of dermal contamination. The average of the total amount of flame retardants removed by twill wipes was greater than the average using gauze, but the difference was not statistically significant.

Assessing occupational exposure to sea lamprey pesticides.

BACKGROUND: Sea lampreys are parasitic fish found in lakes of the United States and Canada. Sea lamprey is controlled through manual application of the pesticides 3-trifluoromethyl-4-nitrophenol (TFM) and Bayluscide(TM) into streams and tributaries. 3-Trifluoromethyl-4-nitrophenol may cause irritation and central nervous system depression and Bayluscide may cause irritation, dermatitis, blisters, cracking, edema, and allergic skin reactions. OBJECTIVES: To assess occupational exposures to sea lamprey pesticides. METHODS: We developed a wipe method for evaluating surface and skin contamination with these pesticides. This method was field tested at a biological field station and at a pesticide river application. We also evaluated exposures using control banding tools. RESULTS: We verified TFM surface contamination at the biological station. At the river application, we found surfaces and worker's skin contaminated with pesticides. CONCLUSION: We recommended minimizing exposures by implementing engineering controls and improved use of personal protective equipment.

Assessment of two portable real-time particle monitors used in nanomaterial workplace exposure evaluations.

BACKGROUND: Nanoparticle emission assessment technique was developed to semi-quantitatively evaluate nanomaterial exposures and employs a combination of filter based samples and portable real-time particle monitors, including a condensation particle counter (CPC) and an optical particle counter (OPC), to detect nanomaterial releases. This laboratory study evaluated the results from CPC and OPC simultaneously measuring a polydisperse aerosol to assess their variability and accuracy. METHODS AND RESULTS: Two CPCs and two OPCs were used to evaluate a polydisperse sodium chloride aerosol within an enclosed chamber. The measurement results for number concentration versus time were compared between paired particle monitors of the same type, and to results from the Scanning Mobility Particle Spectrometer (SMPS) which was widely used to measure concentration of size-specific particles. According to analyses by using the Bland-Altman method, the CPCs displayed a constant mean percent difference of -3.8% (95% agreement limits: -9.1 to 1.6%; range of 95% agreement limit: 10.7%) with the chamber particle concentration below its dynamic upper limit (100,000 particles per cubic centimeter). The mean percent difference increased from -3.4% to -12.0% (range of 95% agreement limits: 7.1%) with increasing particle concentrations that were above the dynamic upper limit. The OPC results showed the percent difference within 15% for measurements in particles with size ranges of 300 to 500 and 500 to 1000 regardless of the particle concentration. Compared with SMPS measurements, the CPC gave a mean percent difference of 22.9% (95% agreement limits: 10.5% to 35.2%); whereas the measurements from OPC were not comparable. CONCLUSIONS: This study demonstrated that CPC and OPC are useful for measuring nanoparticle exposures but the results from an individual monitor should be interpreted based upon the instrument's technical parameters. Future research should challenge these monitors with particles of different sizes, shapes, or composition, to determine measurement comparability and accuracy across various workplace nanomaterials.

Dominant microbial volatile organic compounds in 23 US homes.

Associating Microbial Volatile Organic Compounds (MVOCs) with the species producing them may open the path to more rapid and reliable chemical methods to detect mold problems, especially for mold hidden in wall cavities or small enclosed spaces. This study associated the dominant MVOCs in a convenience sample of 23 homes with the mold species present. Three semi-quantitative predictors of mold growth ("MOW scores") were assessed in the homes through a comparison of basement to main floor areas. MVOC samples were collected and analyzed by GC/MS. Aerotek N-6 samplers were co-located with the MVOC samplers to collect bioaerosols. Concentration and prevalence data for 19 definitive MVOCs were compared with the bioaerosol data. Mold predictor scores were elevated in basement locations as compared with main floor areas. Of the 23 mold genera identified, the predominant genera (ranked occurrences) were Cladosporium, Penicillium, Basidiomycetes, and Aspergilli. The MVOCs 2-octen-1-ol, 3-octenone, 2-heptanone, 1-octen-3-ol, and 1-butanol showed the highest average concentrations (11-37 µg m(-3)), but no single MVOC was significantly elevated in basement locations as compared with main floor living areas in these non-problematic homes. Using a less conservative one-tail test of significance, average 2-octen-1-ol concentrations in basements were higher (p<0.040), and both 3-octenone and 1-octen-3-ol were elevated (p<0.095). Differences in MVOC occurrence were greatest between homes, with MVOCs found in basement locations typically detected in living areas at similar concentrations and frequencies. Based on these findings, the C(8) MVOCs show promise as gross indicators of fungal growth related to the most frequently found mold genera.