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.

Evaluating the potential impact of ototoxicant exposure on worker health.

Occupational exposure to ototoxicants, substances that can cause hearing loss alone or exacerbate hearing loss when exposure occurs in combination with noise, is a workplace hazard that is poorly understood. A review of existing research indicates that some solvents and heavy metals may be ototoxic, but few studies have attempted to estimate the impact of ototoxicant exposure on the United States worker population. Researchers examined trends in workplace exposure to ototoxicants among workers in the United States by comparing exposure data collected by the Occupational Safety and Health Administration against worker hearing loss data provided by the Bureau of Labor Statistics (BLS) for 2012-2019. The study found that the noise exposure data was strongly correlated to the hearing loss data using Pearson's correlation (p < .001), confirming that the exposure data collected by OSHA is predictive of the risk of occupational illness as reported by BLS. Chi-square analysis indicates that reported hearing loss was more common among industry subsectors with exposure to ototoxicants than those without exposure to ototoxicants. These findings suggest that workers with coexposure to ototoxicants and noise may be at a higher risk of experiencing hearing loss than those exposed to noise alone, and action should be taken to minimize this risk.

TSCA risk evaluation-directed characterization of occupational exposures during formaldehyde manufacturing, use as an intermediate, and compounding of formaldehyde-based polymers.

In 2020, the U.S. EPA initiated TSCA risk evaluations for 20 High Priority chemicals, as required by the Lautenberg Act. In addition to consumer exposures, the evaluations include quantitative assessments of worker exposures, hazards and risk. The EPA evaluations of worker exposures, and authority over corrective action to address unacceptably high workplace exposures, overlap OSHA's authority for regulating workplace exposures. This dual federal regulatory authority for risk evaluation and risk management, presents new challenges for industrial hygienists, exposure/risk assessors, and risk managers. One of the chemicals identified as High Priority by the EPA is formaldehyde. In response to these challenges, Celanese supplemented its regular OSHA compliance sampling for formaldehyde with a one-time comprehensive sampling at our sole U.S. formaldehyde manufacturing facility. The sampling characterized all worker populations at the facility, including office workers. Although the EPA assessment is ongoing and may reach different conclusions related to an acceptable exposure limit, 126 full-shift monitoring results demonstrated compliance with the OSHA Formaldehyde Standard (29 CRF 1910.1048) for health protection. Methodologies used to identify workers for exposure monitoring, to characterize multiple EPA-specified worker populations, as well as potential challenges related to the dual regulatory authority for assessing and managing worker exposures are discussed.

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.

Applying the CDC Science Impact Framework to the results of the National Institute for Occupational Safety and Health and the Bureau of Labor Statistics 2001 survey of respirator use and practices.

During 2001-2002, the National Institute for Occupational Safety and Health (NIOSH), at the United States Centers for Disease Control and Prevention, collaborated with the Bureau of Labor Statistics (BLS) at the United States Department of Labor to conduct a voluntary survey of U.S. employers regarding the use of respiratory protective devices. In 2003, the survey results were jointly published by NIOSH and BLS. This study highlights and evaluates the scientific impact of the 2001-2002 survey by using the Science Impact Framework which provides a historical tracking method with five domains of influence. The authors conducted interviews with original project management as well as a thorough document review and qualitative content analysis of published papers, books, presentations, and other relevant print media. A semi-structured and cross-vetted coding was applied across the five domains: Disseminating Science, Creating Awareness, Catalyzing Action, Effecting Change, and Shaping the Future. The 2001-2002 survey findings greatly enhanced understanding and awareness of respirator use in occupational settings within the United States. It also led to similar surveys in other countries, regulatory initiatives by the Occupational Safety and Health Administration and Mine Safety and Health Administration, and ultimately to a renewed partnership between NIOSH and BLS to collect contemporary estimates of respirator use in the workplace within the United States.

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.

Assessment of lead exposure controls on bridge painting projects using worker blood lead levels.

A retrospective analysis of worker blood lead levels (BLL) was conducted using blood lead data collected by four bridge painting contractors before and after lead exposure. The objective of the study was to evaluate the effectiveness of exposure controls in preventing elevated blood lead levels (>25 µg/dl) during bridge painting projects. The contractors selected for the study submitted BLL data for 289 workers representing ten work tasks and 11 bridge painting projects. In total, 713 blood lead levels results were evaluated. The mean blood lead level for all work classifications combined was 10.9 µg/dl at baseline compared with 14.9 µg/dl after two months of exposure and 15.0 µg/dl after four months of exposure. Two months after initial exposure, 29% of the painters and 35% of the laborers had a 10 µg/dl incremental increase or greater in blood lead level. Likewise, 18% of the painters and 26% of the laborers had a blood lead level greater than 25 µg/dl during the same time. The blood lead levels that exceeded the 25 µg/dL threshold ranged from 30µg/dL-63 µg/dL for painters and 26 µg-56 µg/dL for laborers. All work tasks with high-intensity exposure (abrasive blaster/painter, abrasive blaster, painter & laborer) experienced an average blood lead level increase that ranged from 0.2 µg/dl to 8.9 µg/dl two months after initial exposure. Blood lead testing conducted after modified exposure controls (two months after the initial follow-up blood testing) were implemented showed a decrease in average blood lead levels (range -0.14 µg/dl to -2.7 µg/dl) for two high-intensity exposure work tasks. In comparison, the other two high-intensity work tasks had moderate increases (range 1 µg/dl to 2.4 µg/dl). The modified exposure controls included an increase in the air velocity inside of the work containment and an administrative control in the form of additional worker training on lead exposure prevention. The reduction in the 95th percentile (point estimate) BLL exposure profile for each exposure group at the 4-month follow-up blood testing period is associated with modified exposure controls. Ineffective exposure controls were identified through the analysis of worker BLLs. We found two exposure groups (laborer and painter) whose 95th percentile (point estimate) exposure profile was greater than the OSHA construction lead standard's targeted BLL goal (25 µg/dl) during the first two months of exposure. Our research findings provide support for monthly blood lead testing after baseline until blood lead levels are controlled to an acceptable concentration.

Estimation of the number of workers exposed to respirable crystalline silica by industry: Analysis of OSHA compliance data (1979-2015).

BACKGROUND: Respirable crystalline silica (RCS) can potentially cause silicosis, lung cancer, and renal failure. The current study estimates the percentages of workers potentially overexposed to concentrations of RCS dust and silicosis proportional mortality rates (PMRs) by industry. METHODS: Occupational Safety and Health Administration compliance inspection sampling data for RCS collected during 1979 to 2015 were used to estimate percentages of workers exposed. The results were used in combination with US Census Bureau estimates to produce industry specific worker population estimates for 2014. Estimates of the numbers and percentages of workers exposed to RCS concentrations at least 1, 2, 5, and 10 times the National Institute for Occupational Safety and Health recommended exposure limit (REL) were calculated by industry using the 2002 North American Industry Classification System. Silicosis PMRs by industry were estimated using National Center for Health Statistics multiple cause of death data. RESULTS: RCS concentrations/workers exposed were highest in the poured concrete foundation and structure contractors; commercial and institutional building construction; and masonry contractors. Approximately 100 000 workers were exposed above the RCS REL, and most (79%) worked in the construction industry. Tile and terrazzo contractors (12%); brick, stone, and related construction merchant wholesalers (10%); masonry contractors (6%) and poured concrete foundation and structure contractors (6%) were the highest percentages of workers potentially overexposed. PMRs were highest for the structural clay product manufacturing and the foundries industries. CONCLUSION: Percentages of workers exposed to RCS varied by industry and in some industries workers are exposed over 10 times the REL. Exposures can be reduced below the REL by implementing the hierarchy of controls.

Analysis of Occupational Safety and Health Administration (OSHA) noise standard violations over 50 years: 1972 to 2019.

INTRODUCTION: Noise exposure has long been an occupational health concern and has been an important area of focus of the Occupational Safety and Health Administration (OSHA) since its founding. Nevertheless, it remains unclear what effects OSHA's noise standards have had on employer efforts to reduce risks. Consequently, a review of OSHA noise standard violations was performed to clarify the violation trends between 1972 and 2019. METHODS: Using the OSHA Information System, researchers identified 119 305 violations involving four noise standards between 1972 and 2019: 29 CFR 1910.95, occupational noise exposure in general industry; 1926.52, occupational noise exposure in construction; 1926.101, hearing protection in construction, and 1904.10, recording criteria for cases involving occupational hearing loss. Violation frequencies of noise standard subparagraphs and relationships to factors such as industry differences were analyzed using descriptive statistics and t tests. RESULTS: The most commonly violated noise standard was 1910.95 in manufacturing. Such violations rose between 1972 and 1985 and then declined steadily. Whether in general industry or construction, four noise standards were most-frequently cited: lack of feasible administrative or engineering controls (1910.95[b] and 1926.52[d]) and inadequate hearing conservation program (1910.95[c] and 1926.52[b]). These violations were more highly penalized (mean = $1036.50) than other subparagraph violations (mean = $915.80). Programmed and unprogrammed inspections generated similar violation quantities except between 1980 and 1985, when programmed inspections exhibited a sharp spike in violations. CONCLUSION: The study identified trends in OSHA noise standard violations and possible explanations for those trends. The study findings can support development of more practical noise-exposure protection policy.

Too loud? Do powered hand dryers violate federal noise exposure standards?

OBJECTIVE: The aim of this study was to determine if high-powered air hand dryers produce sufficient noise to warrant concern over acoustic trauma as determined by federally established standards. STUDY DESIGN: Prospective observational field data collection SETTING: Urban and suburban community SUBJECTS AND METHODS: Using a NIOSH developed and calibrated soundmeter app, powered hand dryers were measured throughout two metropolitan areas. Ear level measurements were performed while drying wet hands. Recorded variables included average LAeq, Time-Weighted Average, Max and Peak Levels, Noise Dose, and Projected Dose according to NIOSH and OSHA standards, and all three major weighting networks (A, C, and Z). RESULTS: Fifty-four trials were performed at 27 locations. Average dryer run time was 28.9 s (range 14-45 s). Average LAeq (dBA), average maximum level (dBA), and average TWA (dBA) were 90.46 ± 5.32, 94.86 ± 5.73, 59.90 ± 6.80, respectively. The noise generated exceeded published manufacturer specifications. However, even with estimated cumulative daily exposure, the noise generated by these dryers did not exceed federal safety standards. CONCLUSIONS: Air-powered hand dryers produce noise output at a level that many would find subjectively uncomfortable with some brands/models consistently producing noise in excess of 90 dBA. Nonetheless, these dryers do not produce sound exceeding NIOSH standards for noise exposure.

Elevated blood lead levels in adults-Missouri, 2013.

BACKGROUND: Over 90% of adults with elevated blood lead levels (BLLs) in the United States are exposed occupationally. Missouri historically has been among the states with the highest prevalence rates of elevated BLLs. We characterized cases of elevated BLLs among Missouri adults to target preventive interventions. METHODS: We reviewed 2013 data on Missouri residents ≥16 years from the Missouri Adult Blood Lead Epidemiology and Surveillance system and analyzed characteristics of those with elevated BLLs. We used the contemporaneous CDC definition of elevated BLL as ≥10 µg/dL. RESULTS: Of the 15 123 residents with a BLL in 2013 (median: 1.5 µg/dL, range: 0-151 µg/dL), 3145 (21%) had BLLs ≥10 µg/dL. Occupational exposures accounted for the majority of residents (n = 3099, 98%) with elevated BLLs, mostly in battery manufacturing (n = 1373, 44%) and lead mining (n = 821, 26%) industries. CONCLUSIONS: Our findings highlight the need for focused interventions targeting battery manufacturing and lead mining, the high-risk industries, to further reduce overexposures to lead.

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.

Historical evolution of regulatory standards for occupational and consumer exposures to industrial talc.

Talc has been used historically in a wide range of industrial applications and consumer products. The composition and purity of talc used for industrial purposes can vary greatly depending on the source and may contain asbestos minerals. The developing science associated with the health risks of asbestos had an effect on the talc industry throughout the 20th century. This review presents a detailed analysis of the evolution of regulatory standards impacting the use of industrial talc in the U.S. from the early 20th century through the 1990s. While it was recognized by the 1930s that airborne exposures to talc dust at high concentrations could cause lung disease, it was not until later that concerns were raised about the health risks associated with potential occupational exposures to asbestos from industrial talc. Regulatory agencies adopted occupational standards for industrial talc in the early 1970s, but the terminology used to define and characterize talc and other associated minerals varied between agencies. In addition, the complex and varying mineralogy of industrial talc led to inconsistent and imprecise interpretation of studies concerning health risk and occupational health standards among individual agencies.

An overview and impact assessment of OSHA large dairy local emphasis programs in New York and Wisconsin.

BACKGROUND: Farming has been exempted from most labor regulations and shielded from regulatory scrutiny by the Occupational Safety and Health Administration (OSHA). Yet, agriculture and dairy in particular, has relatively high injury and fatality rates. METHODS: A recent shift in OSHA's approach to agricultural worker safety and health includes two dairy-focused Local Emphasis Programs (LEPs), one launched in Wisconsin in 2011 and the other in New York in 2014. We examine data from LEP-related, OSHA consultations and inspections as well as non-governmental audit programs, and review farmer perceptions about the LEP. RESULTS: Inspections conducted by OSHA and private consultation programs highlight the presence and variety of hazards on dairy farms in Wisconsin and New York. CONCLUSION: The LEPs helped raise dairy producers' awareness of inherent hazards and methods to correct them. Farmers cited the LEP as beneficial, identifying it as a catalyst to reduce hazards on their farms.

Employer knowledge of federal requirements for recording work-related injuries and illnesses: Implications for occupational injury surveillance data.

BACKGROUND: Accuracy of the Bureau of Labor Statistics Survey of Occupational Injuries and Illnesses (SOII) data is dependent on employer compliance with workplace injury and illness recordkeeping requirements. Characterization of employer recordkeeping can inform efforts to improve the data. METHODS: We interviewed representative samples of SOII respondents from four states to identify common recordkeeping errors and to assess employer characteristics associated with limited knowledge of the recordkeeping requirements and non compliant practices. RESULTS: Less than half of the establishments required to maintain OSHA injury and illness records reported doing so. Few establishments knew to omit cases limited to diagnostic services (22%) and to count unscheduled weekend days as missed work (27%). No single state or establishment characteristic was consistently associated with better or worse record-keeping. CONCLUSION: Many employers possess a limited understanding of workplace injury recordkeeping requirements, potentially leading them to over-report minor incidents, and under-report missed work cases.

Patterns and predictors of personal protection compliance and workplace hygiene behaviors among workers with elevated blood lead levels in New York State.

Despite increasing awareness and significant progress in reducing lead exposure among workers, elevated blood lead levels (BLLs) continue to be an occupational health problem. Little is currently known about the extent of personal protective equipment (PPE) use among lead-exposed workers. We examined the patterns and predictors of consistent PPE use and workplace hygiene behaviors among workers with elevated BLLs using a survey of 1,459 workers with an occupational lead exposure in New York State (NYS). Routine availability of respirators was commonplace, however only approximately half of workers consistently wore PPE while working with lead. Regular access to showers was reported by 41% of workers, but less than a quarter took showers and subsequently changed into clean clothing before leaving work site. Significant predictors of consistent PPE use and good hygiene behaviors were identified. The findings highlight the need for further educational and policy interventions for lead-exposed employees. Increased employer efforts are also required to provide workplace structures and a culture that supports compliance. These include the provision of routine training and hazard communication, provision of appropriate PPE and hygiene facilities, and enforcing its use where necessary.

MeClas: An online tool for hazard identification and classification of complex inorganic metal-containing materials.

MeClas is a web-based tool to generate (eco)toxicity hazard categories and corresponding classification & labelling information of inorganic metal-containing complex materials such as ores, concentrates, intermediates or alloys for which the manual application of the GHS/CLP rules is very complex and requires a high level of consistency. The tool comprises several tiers, aimed at the progressive refinement of classification through recognition of specific mineral content, speciation/mineralogy up to bio-availability corrections. Where relevant in a regional jurisdiction (EU and US), mandatory classification references are used complementary to high quality (eco)toxicity reference values (ERV/TRV) and self-classifications. MeClas addresses the GHS human health and environmental hazard endpoints, is based on an unambiguous algorithm defined under GHS/CLP, has a well defined domain of applicability and robust predictability. MeClas allows a consistent approach across companies in line with GHS ruling (and regional implementations), considering the metal specificities and related classification GHS/CLP Guidance, and the most up to date (eco)-toxicological hazard information on self-classifications and ERV/TRV.

Carbon Dioxide Exposure Resulting From Hood Protective Equipment Used in Joint Arthroplasty Surgery.

BACKGROUND: To protect both the surgeon and patient during procedures, hooded protection shields are used during joint arthroplasty procedures. Headache, malaise, and dizziness, consistent with increased carbon dioxide (CO2) exposure, have been anecdotally reported by surgeons using hoods. We hypothesized that increased CO2 concentrations were causing reported symptoms. METHODS: Six healthy subjects (4 men) donned hooded protection, fan at the highest setting. Arm cycle ergometry at workloads of 12 and 25 watts (W) simulated workloads encountered during arthroplasty. Inspired O2 and CO2 concentrations at the nares were continuously measured at rest, 12 W, and 25 W. At each activity level, the fan was deactivated and the times for CO2 to reach 0.5% and 1.0% were measured. RESULTS: At rest, inspired CO2 was 0.14% ± 0.04%. Exercise had significant effect on CO2 compared with rest (0.26% ± 0.08% at 12 W, P = .04; 0.31% ± 0.05% at 25 W, P = .003). Inspired CO2 concentration increased rapidly with fan deactivation, with the time for CO2 to increase to 0.5% and 1.0% after fan deactivation being rapid but variable (0.5%, 12 ± 9 seconds; 1%, 26 ± 15 seconds). Time for CO2 to return below 0.5% after fan reactivation was 20 ± 37 seconds. CONCLUSION: During simulated joint arthroplasty, CO2 remained within Occupational Safety and Health Administration (OSHA) standards with the fan at the highest setting. With fan deactivation, CO2 concentration rapidly exceeds OSHA standards.

Determination of airborne concentrations of dichlorvos over a range of temperatures when using commercially available pesticide strips in a simulated military guard post.

Dichlorvos is a chemical compound which has been used for decades as a pesticide. Potential inhalational exposure to dichlorvos vapor associated with using commercially-based, dichlorvos-impregnated resin strips in a simulated military guard post was evaluated. A varying number of these pesticide strips, ranging from the manufacturer's guidelines ((3)-16 g strips) up to a full package of strips ((12)-16 g strips), were placed in a small, enclosed space (2.31 m x 2.26 m x 2.44 m, 12.7 m3), which was similar in size to a typical military guard post. Static air sampling was then conducted to simulate personal air sampling, followed by analysis using OSHA Method 62 (GC-ECD). Air sampling was conducted over a range of discrete temperatures (26-38˚C) which approximated average ambient temperatures expected in a variety of deployed environments. Air sampling in this range was conducted to determine the airborne concentration generated at each temperature setting. Airborne concentrations were then compared to established short term military exposure guidelines (MEGs) and the 8-hr OSHA permissible exposure limit (PEL) for dichlorvos (both criteria limits are 0.99 mg/m3). Results from air sampling indicated that exceeding the manufacturer-recommended number of strips for the workspace volume and environmental conditions produced airborne dichlorvos concentrations above established occupational standards (1.77-3.70 mg/m3). Such exposures may potentially lead to adverse effects, such as loss of mental and visual acuity for guard post watch standers who employ more strips within a space than recommended per the manufacturer for the size of the space. However, concentrations of airborne dichlorvos generated when adhering to manufacturer's guidelines based on workspace volume resulted in levels of 0.16-0.39 mg/m3 for 1-hr and 8-hr timeframes, which were below the established occupational health limits. While dichlorvos-impregnated strips are not currently recommended for use in manned workspaces for periods > 4 hr, findings suggest that prolonged use (8 hr) of similar pesticide strips within manned spaces to repel and/or kill disease-carrying insects may be possible without experiencing adverse health effects.