Farmworker-Relevant Heat Exposure in Different Crop and Shade Conditions.

OBJECTIVES: Agricultural workers are at risk of heat-related illness, which is preventable. Few field studies have compared farmworker-relevant heat exposure in different conditions. We examined heat exposure over time in different potential shade and work locations to inform future occupational heat prevention approaches. METHODS: We assessed heat exposure in Eastern Washington State (WA) cherry and grape fields in August 2022. QUESTemp° monitors recorded Wet Bulb Globe Temperature (WBGT) and Black Globe Temperature (BGT) every 10 min from approximately 07:00-14:00 for three days in the center of crop rows (mid-row), under portable shade structures (shade), and in open field (open) locations. Linear mixed effects regression (LMER) models compared WBGT and BGT among field locations. Hourly time-weighted average WBGT and comparisons with occupational exposure limits (OELs) were computed for different hypothetical work-rest cycles during the hottest sampling hours, assuming different worker effort levels, rest locations (mid-row versus shade), and acclimatization statuses. RESULTS: Across all crops and locations during the study period, the mean/SD air temperature was 31°C (88°F)/3.9°C (6.9°F), with a maximum temperature of 39°C (102°F) and a mean/SD relative humidity of 30%/9.6%. LMER models suggested no significant difference in mid-row versus open WBGT but significantly lower WBGT in shade versus open locations for both cherries (main effect -5.14: 95% confidence interval [CI] -6.97,-3.32) and grapes (-6.20: 95%CI -7.73,-4.67), though this difference diminished over the course of the day. BGT was significantly higher in the mid-row than the shade (cherries main effect 14.33: 95%CI 9.52,19.13 and grapes 17.10: 95%CI 13.44,20.75). During the hottest sampling hour, the exceedances of OELs were reduced with assumptions of increased shaded break lengths, reduced effort level, and acclimatization. CONCLUSIONS: Shade canopies, but not the crops studied, provided significant reductions in heat exposure. We observed increased protection from heat assuming longer shaded breaks and reduced effort levels. Results highlight the need for additional field research on the effectiveness, feasibility, and acceptability of different shade types and work-rest cycles to guide employer optimization of best practices for worker protections, including acclimatization before high heat, sufficient shaded rest time, reduced effort levels as the day warms, and avoiding work in peak heat.

Descriptive summary of fatal work-related injuries, Western States, 2011-2017.

Work-related deaths are a persistent occupational health issue that can be prevented. However, prevention opportunities can be hampered by a lack of adequate public health resources. The Western States Occupational Network (WestON) is a network of federal, state, and local occupational health professionals that includes a 19-state region of the United States. To encourage public health collaboration, WestON partners examined work-related fatalities within the region. Fatality counts (numerators) were obtained from the U.S. Bureau of Labor Statistics (BLS) Census of Fatal Occupational Injuries restricted-access research files for all workers ages ≥15 years and fatally injured in WestON states from 2011 through 2017. Estimates of full-time equivalent hours worked (FTE) (denominators) were retrieved from the BLS Current Population Survey. Annual average fatality rates were calculated as number of fatalities per 100,000 FTE over the study period. Rates were stratified by state, select demographics, industry sector, and event/exposure types. Pearson chi-squared tests and rate ratios with 95% confidence probability limits were used to assess rate differences. All analyses were conducted using SAS v.9.4. From 2011 through 2017, the annual average overall occupational fatality rate for the WestON region was 3.5 fatalities per 100,000 FTE, comparable to the overall U.S. fatality rate. Male workers had a fatality rate almost 10 times higher than female workers in the region. Fatality rates increased with successive age groups. Alaska and New Mexico had significantly higher fatality rates for all racial/ethnic groups compared to respective regional rates. Wyoming, North Dakota, and Montana had the three highest occupational fatality rates among foreign-born workers. Agriculture/forestry/fishing, mining/oil/gas extraction, and transportation/warehousing/utilities were industry sector groups with the three highest fatality rates regionally. Transportation-related incidents were the most frequent event type associated with occupational fatalities for all 19 states. Work-related fatalities are a crosscutting occupational public health priority. This analysis can be an impetus for collaborative multistate initiatives among a dynamic and varied occupational public health network to better meet the needs of a rapidly changing workforce.

Isocyanate Exposure Below Analytical Detection When a Paint Brush and Roller Are Used to Apply Moisture-Cure Polyurethane Paint.

Isocyanate exposure is known to be hazardous when polyurethane paints are applied with a spray gun, but less is known of exposure when paint is applied with a paint brush and roller. Concentrations of 1,6-hexamethylene diisocyanate (HDI) monomer and three HDI polymers were assessed when two moisture-cure polyurethane paints containing 31-35% isocyanates were applied with a paint roller and brush. Short-term 15-min samples were taken during paint application in an indoor test environment with no ventilation (n= 12); in an outdoor test environment (n= 11); and in an outdoor in-situ assessment (n= 22). The outdoor in-situ assessment involved the painting of a bus shelter and light poles at a public transit station over two night shifts. All isocyanate samples were below analytical detection. The analytical limits of detection for HDI monomer, HDI biuret, HDI isocyanurate, and HDI uretdione were 0.005, 0.84, 0.87, and 0.88 µg, respectively. The finding that isocyanate concentrations were below detection is attributed to the use of paint roller and brush which minimize paint aerosolization and the paint formulation itself which contained <1% of volatile HDI monomer.

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.

Personal exposure to metal fume, NO2, and O3 among production welders and non-welders.

The objective of this study was to characterize personal exposures to welding-related metals and gases for production welders and non-welders in a large manufacturing facility. Welding fume metals and irritant gases nitrogen dioxide (NO(2)) and ozone (O(3)) were sampled for thirty-eight workers. Personal exposure air samples for welding fume metals were collected on 37 mm open face cassettes and nitrogen dioxide and ozone exposure samples were collected with diffusive passive samplers. Samples were analyzed for metals using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and welding fume metal exposure concentrations were defined as the sum of welding-related metals mass per volume of air sampled. Welding fume metal exposures were highly variable among similar types of welding while NO(2) and O(3) exposure were less variable. Welding fume metal exposures were significantly higher 474 µg/m(3) for welders than non-welders 60 µg/m(3) (p=0.001). Welders were exposed to higher concentrations of NO(2) and O(3) than non-welders but the differences were not statistically significant. Welding fume metal exposure concentrations for welders performing gas metal arc welding (GMAW) and shielded metal arc welding (SMAW) were higher than welders performing gas tungsten arc welding (GTAW). Non-welders experienced exposures similar to GTAW welders despite a curtain wall barrier separating welding and non-welding work areas.

Prioritizing prevention opportunities in the Washington State construction industry, 2003-2007.

OBJECTIVE: This study compares construction industry groups in Washington State by injury severity and cost, and ranks industry groups according to potential for prevention. METHODS: All Washington State workers' compensation compensable claims with date of injury between 2003 and 2007 were classified into North American Industrial Classification System (NAICS) industry groups. Claims were then aggregated by injury type and industry groups were ranked according to a prevention index (PI). The PI is the average of the rank orders of the claim count and the claim incidence rate. A lower PI indicates a higher need for prevention activities. The severity rate was calculated as the number of days of time loss per 10,000 full-time equivalents (FTEs). RESULTS: For all injury types, construction industry groups occupy 7 of the top 15 PI ranks in Washington State. The severity rate among construction industry groups was twice that for non-construction groups for all injury types. Foundation, structure, and building exterior contractors (NAICS 2381) ranked highest in prevention potential and severity among construction industry groups for most common injury types including falls from elevation, fall on same level, struck by/against, and musculo-skeletal disorders of the neck, back, and upper extremity (WMSDs). Median claim costs by injury type were generally higher among construction industry groups. CONCLUSIONS: The construction industry in Washington State has a high severity rate and potential for prevention. The methods used for characterizing these industry groups can be adapted for comparison within and between other industries and states. IMPACT ON INDUSTRY: These data can be used by industry groups and employers to identify higher cost and higher severity injury types. Knowledge about the relative frequencies and costs associated with different injury types will help employers and construction industry associations make better informed decisions about where prevention efforts are most needed and may have the greatest impact. The results of this study can also be used by industry stakeholders to cooperatively focus on high cost and high severity injuries and explore best practices, interventions, and solutions as demonstrated by efforts to prevent musculoskeletal disorders in masonry (Entzel, Albers, & Welch, 2007). Initiating construction industry groups to focus on high cost and high severity injuries may also help prevent other types of injuries.

Concentration and emission of airborne contaminants in a laboratory animal facility housing rabbits.

Characterization of animal housing conditions can determine the frequency of bedding and cage changes, which are not standardized from facility to facility. Rabbits produce noticeable odors, and their excreta can scald and stain cages. Our facility wanted to document measurable airborne contaminants in a laboratory rabbit room in which excreta pans were changed weekly and cages changed biweekly. Contaminants included particulate, endotoxin, ammonia, carbon dioxide, and a rabbit salivary protein as a marker for rabbit allergen. Concentrations were measured daily over a 2-wk period in a laboratory animal facility to determine whether they increased over time and on days considered to be the dirtiest. Except for ammonia, concentrations of all airborne contaminants did not differ between clean and dirty days. Concentrations were lower than occupational health exposure guidelines for all contaminants studied, including ammonia. After measurement of concentration, a model was applied to calculate mean emission factors in this rabbit room. Examples of emission factor utilization to determine airborne contaminant concentration in rabbit rooms under various environmental conditions and housing densities are provided.

Demolition of high-rise public housing increases particulate matter air pollution in communities of high-risk asthmatics.

Public housing developments across the United States are being demolished, potentially increasing local concentrations of particulate matter (PM) in communities with high burdens of severe asthma. Little is known about the impact of demolition on local air quality. At three public housing developments in Chicago, IL, PM with an aerodynamic diameter < 10 microm (PM10) and < 2.5 microm were measured before and during high-rise demolition. Additionally, size-selective sampling and real-time monitoring were concurrently performed upwind and downwind of one demolition site. The concentration of particulates attributable to demolition was estimated after accounting for background urban air pollution. Particle microscopy was performed on a small number of samples. Substantial increases of PM10 occurred during demolition, with the magnitude of that increase varying based on sampler distance, wind direction, and averaging time. During structural demolition, local concentrations of PM10 42 m downwind of a demolition site increased 4- to 9-fold above upwind concentrations (6-hr averaging time). After adjusting for background PM10, the presence of dusty conditions was associated with a 74% increase in PM10 100 m downwind of demolition sites (24-hr averaging times). During structural demolition, short-term peaks in real-time PM10 (30-sec averaging time) occasionally exceeded 500 microg/m(3). The median particle size downwind of a demolition site (17.3 microm) was significantly larger than background (3 microm). Specific activities are associated with realtime particulate measures. Microscopy did not identify asbestos or high concentrations of mold spores. In conclusion, individuals living near sites of public housing demolition are at risk for exposure to high particulate concentrations. This increase is characterized by relatively large particles and high short-term peaks in PM concentration.

Dust emission rates from food processing.

A field study was performed to develop emission rates for dust exposure at a food processing facility. Eight 2-hour periods were monitored over 2 days. Area total suspended particulate samples were collected on 37 mm polyvinyl chloride filters with 5 mum pore size according to NIOSH Method 0500. Filters were analyzed gravimetrically. Ventilation and production activity data were collected during air sampling. Two mass balance models were used to calculate emission rates. The first was an experimental mass balance model, with the mass of contaminant generated determined by air flow and concentration measurements at room exit and entry points. The second treated the work environment as a completely mixed space, utilizing ventilation and area concentration measurements. Emission rates generated from mass balance models ranged from 2.09-542 mg/min for the various processing operations and food products. Process emission rates with production activity data allow estimation of dust exposure in similar facilities, and help direct development of exposure control strategies.

Large-volume injection PTV-GC-MS analysis of polycyclic aromatic hydrocarbons in air and sediment samples.

For the analysis of trace organic pollutants in environmental samples using a gas chromatographic (GC) instrument, large-volume injection using the programmable temperature vaporization (PTV) technique has many advantages over the traditional split/splitless injection. By increasing the injection volume from 1 or 2 microL with a split/splitless inlet to 60 microL or higher with the PTV inlet, analytical sensitivity is greatly enhanced for analytes with low concentrations. Results obtained from optimization of instrument operational parameters for analyzing polycyclic aromatic hydrocarbons (PAHs) are reported in this paper. The laboratory method detection limits for 16 PAHs and six deuterated PAH surrogates were determined using seven replicate spike samples. The initial temperature of the inlet was found to be critical in determining the analytical sensitivity of PAHs with two or three rings due to loss of these relatively highly volatile compounds during solvent vaporization. For most PAHs, the response of the mass spectrometry detector increased proportionally as the total injected volume was increased up to 150 microL. Significant interference from rubber material of the sample vial septa was observed.