Toxic inhalation of sodium metabisulphite by-products from a shipping container

Logistics workers who handle cargo containers are at risk of toxic inhalation injuries, although prevalence and severities of these injuries are not well characterized. We report on a previously healthy 37-year-old supervisor who was acutely exposed to sodium metabisulphite and its thermal degradation by-products during a routine inspection of a shipping container. The employee developed chemical pneumonitis with acute non-cardiogenic pulmonary oedema and subsequent severe reactive airway dysfunction syndrome.

Severe Silicosis in Engineered Stone Fabrication Workers - California, Colorado, Texas, and Washington, 2017-2019

Silicosis is an incurable occupational lung disease caused by inhaling particles of respirable crystalline silica. These particles trigger inflammation and fibrosis in the lungs, leading to progressive, irreversible, and potentially disabling disease. Silica exposure is also associated with increased risk for lung infection (notably, tuberculosis), lung cancer, emphysema, autoimmune diseases, and kidney disease (1). Because quartz, a type of crystalline silica, is commonly found in stone, workers who cut, polish, or grind stone materials can be exposed to silica dust. Recently, silicosis outbreaks have been reported in several countries among workers who cut and finish stone slabs for countertops, a process known as stone fabrication (2-5). Most worked with engineered stone, a manufactured, quartz-based composite material that can contain >90% crystalline silica (6). This report describes 18 cases of silicosis, including the first two fatalities reported in the United States, among workers in the stone fabrication industry in California, Colorado, Texas, and Washington. Several patients had severe progressive disease, and some had associated autoimmune diseases and latent tuberculosis infection. Cases were identified through independent investigations in each state and confirmed based on computed tomography (CT) scan of the chest or lung biopsy findings. Silica dust exposure reduction and effective regulatory enforcement, along with enhanced workplace medical and public health surveillance, are urgently needed to address the emerging public health threat of silicosis in the stone fabrication industry.

Work-related asthma surveillance in Washington State: time trends, industry rates, and workers' compensation costs, 2002-2016

Objective: Washington State's work-related asthma (WRA) surveillance program utilizes workers' compensation (WC) data as its primary data source and has spanned a 15-year time period. This study analyses trends for WRA claim incidence rates compared to all WC claim incidence rates. WRA claim incidence rates and WC costs are analyzed by industry. Methods: Potential WRA cases were identified through the WC system and through direct provider report and classified by industry, age, and year of illness onset. WRA claim rates by industry and year were calculated using total work hours reported by employers covered by the WC system. Claim costs for accepted claims were compared by industry and year. Results: WRA claim incidence rates decreased 8.9% (95% CI: -10.6, -7.2) annually for the time period 2002-2016. The decline in WRA claim incidence rate is slightly faster than the incidence rate for all WC claims which had its steepest decrease from 2007 to 2010 at an estimated annual 8.4% decrease (95% CI: -11.8, -5.0). WRA claim rates were highest for workers in Public Administration, Manufacturing, and the Agricultural, Forestry, Fishing and Hunting industries. Median claim costs for WRA did not change significantly by year (p = 0.2, range $595-$1442) and the distribution of WRA WC claim costs by industry were highest in Manufacturing (21.3%) and Construction (16.4%) industries. Conclusion: WRA claim incidence rates are declining in Washington State. The cause for the decline is unclear. Workers across all industries in Washington remain at risk for WRA.

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.

Respiratory disease associated with occupational inhalation to hop (Humulus lupulus) during harvest and processing

BACKGROUND

There is little published evidence for occupational respiratory disease caused by hop dust inhalation. In the United States, hops are commercially produced in the Pacific Northwest region.

OBJECTIVE

To describe occupational respiratory disease in hop workers.

METHODS

Washington State workers' compensation claims filed by hop workers for respiratory disease were systematically identified and reviewed. Incidence rates of respiratory disease in hop workers were compared with rates in field vegetable crop farm workers.

RESULTS

Fifty-seven cases of respiratory disease associated with hop dust inhalation were reported from 1995 to 2011. Most cases (61%) were diagnosed by the attending health care practitioner as having work-related asthma. Seven percent of cases were diagnosed as chronic obstructive pulmonary disease, and the remaining cases were diagnosed as allergic respiratory disorders (eg, allergic rhinitis) or asthma-associated symptoms (eg, dyspnea). Cases were associated with hop harvesting, secondary hop processing, and indirect exposure. The incidence rate of respiratory disease in hop workers was 15 cases per 10,000 full-time workers, which was 30 times greater than the incidence rate for field vegetable crop workers. A strong temporal association between hop dust exposure and respiratory symptoms and a clear association between an increase in hop dust concentrations and the clinical onset of symptoms were apparent in 3 cases.

CONCLUSION

Occupational exposure to hop dust is associated with respiratory disease. Respiratory disease rates were higher in hop workers than in a comparison group of agricultural workers. Additional research is needed before hop dust can be confirmed as a causative agent for occupational asthma.

Survey of dermal protection in Washington State collision repair industry

Substantial exposure to isocyanates may occur during spray painting in autobody shops, yet information is lacking on the efficacy of the protective clothing used during spray painting. We investigated the personal and workplace factors associated with painters' dermal protection use during a large-scale exposure assessment study. Survey data indicated that 69% of painters always used gloves, with latex gloves (47%) and nitrile gloves (34%) used most frequently. Among latex glove users, 53% used thin latex (0.05-0.13 mm), 6% used medium latex (0.15-0.20 mm), and 12% used thick latex (> 0.20 mm). Among nitrile glove users, 27% used thin nitrile and 45% used medium nitrile. Sixty-three percent of painters always used coveralls, 44% preferring one particular brand. Although overspray presents an opportunity for dermal exposure to the neck and face, only 19% of painters protected these areas with personal protective equipment. Painters who always used coveralls were more likely to use gloves (odds ratio = 7.9, p = 0.061). Painters who reported ever having smoked cigarettes used gloves (p = 0.05) and coveralls (p = 0.04) more frequently. Painters who sprayed more than 34 clear coat jobs per month used coveralls most frequently (p = 0.038). Exact logistic regressions along with random sample calculations indicated that the survey results were independent of the shops. Because of the small sample size in this study, future research is warranted to corroborate these results. Studying the effectiveness of gloves and coveralls against polyurethane paints and understanding the underlying motivators and preferences for painters and business owners is needed for the development of best practices for the selection and use of dermal protection.

Work-related asthma in Washington State

OBJECTIVE

Asthma is a common and costly public health problem. Occupational exposures contribute to the burden of asthma. Identifying workplace exposures and industries and occupations at risk can lead to more effective prevention measures.

METHODS

Data from Washington State's work-related asthma (WRA) surveillance program from October 2001 to December 2008 were analyzed. Workers' compensation records, physician reports, and telephone interviews were used to describe the occurrence of WRA during this time, in order to identify contributing exposure sources and industries and occupations that are associated with WRA in Washington.

RESULTS

There were 1343 identified WRA cases in Washington State during this time. Of these, 1285 were workers' compensation claims, with a total medical cost for State Fund claims of approximately $3 million dollars. The top three sources identified were miscellaneous chemicals and materials, mineral and inorganic dusts, and plant material. Plant material claims proved to be widespread throughout various industries, were largely classified as new-onset asthma cases, and had higher median medical cost and higher median time loss days than cases associated with other exposure sources.

CONCLUSIONS

Washington State has an abundance of plant-material-related WRA cases among US states conducting WRA surveillance. Washington State's industry mix might explain the higher prevalence of cases, particularly its logging and wood processing industries and as a world leader in hops production. In Washington, further WRA prevention efforts should emphasize workplaces working with plant materials.

Occupational carbon monoxide poisoning in Washington State, 2000-2005

Washington State workers' compensation data can be used to guide prevention efforts focused on occupational carbon monoxide (CO) poisoning. Between 2000 and 2005, a total of 345 individual claims comprising 221 different exposure incidents were identified for the 6-year time period. The construction industry had 43 (20%) CO incidents, followed by wholesale trade with 32 (15%), and agriculture with 27 (12%) incidents. Fuel-powered forklifts caused 29% of all incidents, while autos/trucks/buses were responsible for 26%. The number of forklift incidents in fruit packing and cold storage companies declined significantly from 1994 through 2007 (Spearman's rho = 0.6659, p < 0.01). While this study used multiple medical records from workers' compensation claims to identify CO poisoning, a surveillance system that lacks extensive medical records may rely principally on carboxyhemoglobin (COHb) tests. This study demonstrated that 71% of the identified workers' compensation claims had associated COHb tests. The recurrence and timing of CO poisoning as well as control of the CO-generating source were determined. Approximately 8% of all work sites had recurring CO poisoning incidents. Two percent experienced a recurrent incident within 16 days of the initial incident, and 6% experienced a recurrent incident between 16 days and 3 years after the initial incident. Sixty-seven percent of claimants exposed to CO were not in direct control of the CO-generating source; this has implications for CO prevention and underscores the need for all employees to be trained on CO hazards.

Surveillance of Washington OSHA exposure data to identify uncharacterized or emerging occupational health hazards

Chemical substance exposure data from the Washington State Occupational Safety and Health Administration (OSHA) program were reviewed to determine if inspections conducted as a result of a report of a hazard from a complainant or referent may alert the agency to uncharacterized or emerging health hazards. Exposure and other electronically stored data from 6890 health inspection reports conducted between April 2003 and August 2008 were extracted from agency records. A total of 515 (7%) inspections with one or more personal airborne chemical substance samples were identified for further study. Inspections by report of a hazard and by targeting were compared for the following: number of inspections, number and percentage of inspections with workers exposed to substances above an agency's permissible exposure limit, types of industries inspected, and number and type of chemical substances assessed. Report of a hazard inspections documented work sites with worker overexposure at the same rate as agency targeted inspections (approximately 35% of the time), suggesting that complainants and referents are a credible pool of observers capable of directing the agency to airborne chemical substance hazards. Report of a hazard inspections were associated with significantly broader distribution of industries as well as a greater variety of chemical substance exposures than were targeted inspections. Narrative text that described business type and processes inspected was more useful than NAICS codes alone and critical in identifying processes and industries that may be associated with new hazards. Finally, previously identified emerging hazards were found among the report of a hazard data. These findings indicate that surveillance of OSHA inspection data can be a valid tool to identify uncharacterized and emerging health hazards. Additional research is needed to develop criteria for objective review and prioritization of the data for intervention. Federal OSHA and other state OSHA agencies will need to add electronic data entry fields more descriptive of industry, process, and substance to fully use agency exposure data for hazard surveillance.

Accuracy of task recall for epidemiological exposure assessment to construction noise

AIMS

To validate the accuracy of construction worker recall of task and environment based information; and to evaluate the effect of task recall on estimates of noise exposure.

METHODS

A cohort of 25 construction workers recorded tasks daily and had dosimetry measurements weekly for six weeks. Worker recall of tasks reported on the daily activity cards was validated with research observations and compared directly to task recall at a six month interview.

RESULTS

The mean L(EQ) noise exposure level (dBA) from dosimeter measurements was 89.9 (n = 61) and 83.3 (n = 47) for carpenters and electricians, respectively. The percentage time at tasks reported during the interview was compared to that calculated from daily activity cards; only 2/22 tasks were different at the nominal 5% significance level. The accuracy, based on bias and precision, of percentage time reported for tasks from the interview was 53-100% (median 91%). For carpenters, the difference in noise estimates derived from activity cards (mean 91.9 dBA) was not different from those derived from the questionnaire (mean 91.7 dBA). This trend held for electricians as well. For all subjects, noise estimates derived from the activity card and the questionnaire were strongly correlated with dosimetry measurements. The average difference between the noise estimate derived from the questionnaire and dosimetry measurements was 2.0 dBA, and was independent of the actual exposure level.

CONCLUSIONS

Six months after tasks were performed, construction workers were able to accurately recall the percentage time they spent at various tasks. Estimates of noise exposure based on long term recall (questionnaire) were no different from estimates derived from daily activity cards and were strongly correlated with dosimetry measurements, overestimating the level on average by 2.0 dBA.

Reaching managers at an industry association conference: evaluation of ergonomics training

Managers rarely receive targeted safety and health training, despite the belief that management support is important for a successful workplace safety and health program. A program evaluation was performed on an ergonomics workshop for managers attending an industry association conference. The goals were to determine whether the conference was an effective setting for the training, to assess whether the training led to an increase in participants' knowledge and ability, and to determine whether participants could use what was taught in an applied exercise. The majority of participants (97%) believed the conference was an effective setting for the training. Participants' knowledge and ability to identify musculoskeletal risks increased significantly following the training. Additionally, participants were able to identify musculoskeletal risk factors and suggest solutions during the applied exercise. Occupational health nurses should consider trade association meetings as a venue for educational training sessions and for disseminating their research results.

The impact of reduced frequency of cage changes on the health of mice housed in ventilated cages

Our purpose in this investigation was to determine if we could reduce cage changing frequency without adversely affecting the health of mice. We housed mice at three different cage changing frequencies: 7, 14, and 21 days, each at three different cage ventilation rates: 30, 60 and 100 air changes per hour (ACH), for a total of nine experimental conditions. For each condition, we evaluated the health of 12 breeding pairs and 12 breeding trios of C57BL/6J mice for 7 months. Health was assessed by breeding performance, weanling weight and growth, plasma corticosterone levels, immune function, and histological examination of selected organs. Over a period of 4 months, we monitored the cage microenvironment for ammonia and carbon dioxide concentrations, relative humidity, and temperature one day prior to changing the cage. The relative humidity, carbon dioxide concentrations, and temperature of the cages at all conditions were within acceptable levels. Ammonia concentrations remained below 25 ppm (parts per million) in most cages, but, even at higher concentrations, did not adversely affect the health of mice. Frequency of cage changing had only one significant effect; pup mortality with pair matings was greater at the cage changing frequency of 7 days compared with 14 or 21 days. In addition, pup mortality with pair matings was higher at 30 ACH compared with other ventilation rates. In conclusion, under the conditions of this study, cage changes once every 14 days and ventilation rates of 60 ACH provide optimum conditions for animal health and practical husbandry.

Control strategies for aeroallergens in an animal facility

BACKGROUND

Prevalence of the occupational disease laboratory animal allergy could be reduced if aeroallergen reduction strategies are identified.

OBJECTIVE

To reduce worker exposure to Mus m 1, an allergen from laboratory mice, the effect of filter cage tops, increased room ventilation, negatively pressurized ventilated cages, and ventilated cage-changing tables were evaluated.

METHODS

Aeroallergen was collected in the ambient air and in the breathing zone and quantified by using a competitive immunoassay.

RESULTS

When mice were housed in unventilated cages, ambient allergen was reduced from 5.1 ng/m3 with no cage top to 1.3 ng/m3 with a simple filter-sheet top and 0.8 ng/m3 with a fitted filter-bonnet top (P <. 05). Room ventilation was increased from 6 to 10, 15, and 20 air changes per hour and had little effect on aeroallergen levels and no impact on airborne particulate matter. When mice were housed in ventilated cages, ambient allergen was significantly reduced from 1. 1 ng/m3 at positive cage pressure to 0.3 ng/m3 at negative cage pressure (P <.05). Negative cage pressure combined with handling animals under a ventilated table reduced breathing zone allergen from 28 ng/m3 with neither control strategy in place to 9 ng/m3 (P <. 05). Use of a ventilated table controlled bacterial contamination, measured as colony forming units, found in negatively pressurized cages.

CONCLUSION

Three aeroallergen control strategies are use of filter cage tops, operation of negatively pressurized cages, and use of ventilated changing tables.