Health Hazard Evaluations (HHEs)

(2021) Exposures to metals and a perceived excess of cancer cases in a train maintenance facility. (Click to open report)
The Health Hazard Evaluation Program received a request from a union at a train maintenance facility concerning employee exposure to metals and a perceived excess of cancer. We visited the facility twice and focused our evaluation on first shift employees working in six shops (truck, wheel, motor, electronics, contactor, and tin) that worked on different maintenance and repair tasks. We observed work processes, work practices, and conditions; spoke informally to employees in each shop about heal... (Click to show more) The Health Hazard Evaluation Program received a request from a union at a train maintenance facility concerning employee exposure to metals and a perceived excess of cancer. We visited the facility twice and focused our evaluation on first shift employees working in six shops (truck, wheel, motor, electronics, contactor, and tin) that worked on different maintenance and repair tasks. We observed work processes, work practices, and conditions; spoke informally to employees in each shop about health and safety concerns; measured employee exposures to metals in air; administered medical surveys; and measured blood lead levels of employees in the electronics shop. Our air sampling showed that there were no exposures to metals above relevant occupational exposure limits; however, employees remained concerned about potential exposures to metals and dust. Blood lead levels were all below the CDC reference level of 5 micrograms per deciliter. We found that training and hazard communication could be improved. For example, employees expressed concern about potential exposures to varnish chemicals and cadmium. However, management ceased the vacuum pressure impregnation process for applying varnish and enclosed the cadmium-containing contactors. Employees were also concerned about their health, specifically their respiratory health and a perceived excess risk of cancer. The results from our evaluation were not consistent with the reported cancers being caused by a work-related exposure. We recommended providing periodic training and communication around concerns about chemical exposures, visible dust in the facility, cadmium in the contactor shop, personal protective equipment requirements, and the perceived excess of cancer cases. We recommended reinforcing the importance of daily and weekly cleaning of commonly used areas of all workstations and break areas. We also recommended using wet methods or high efficiency particulate air filter vacuums to clean metal dust; ways to improve the spray-painting process; removing latex gloves from the facility; and consuming food and beverages away from production areas. (Click to show less)
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(2020) Exposures and respiratory health at a coffee roasting, flavoring, and packaging facility. (Click to open report)
Physicians at a university medical center diagnosed obliterative bronchiolitis, a serious, often disabling lung disease, in five former employees of the coffee roasting, flavoring, and packaging facility. In April 2012, the National Institute for Occupational Safety and Health's Health Hazard Evaluation Program received a confidential employee request from a coffee roasting, flavoring, and packaging facility with approximately 85 employees. The requestors had concerns about respiratory symptoms,... (Click to show more) Physicians at a university medical center diagnosed obliterative bronchiolitis, a serious, often disabling lung disease, in five former employees of the coffee roasting, flavoring, and packaging facility. In April 2012, the National Institute for Occupational Safety and Health's Health Hazard Evaluation Program received a confidential employee request from a coffee roasting, flavoring, and packaging facility with approximately 85 employees. The requestors had concerns about respiratory symptoms, lung disease, and eye irritation related to the manufacturing of coffee products, including ingredients used in the flavoring process. In July/August 2012, we conducted an initial walk-through site visit at the facility. In September 2012, we conducted a medical survey; we administered a questionnaire, performed breathing tests, and measured antibodies in blood. In November 2012, we conducted an industrial hygiene survey and ventilation assessment at the facility. The industrial hygiene survey consisted of collecting personal breathing zone and area air samples for alpha-diketones (i.e., diacetyl and 2,3-pentanedione) and dust. Bulk samples of whole bean green and roasted coffee, ground roasted coffee, and liquid flavorings were collected to evaluate the potential for emission of diacetyl and 2,3-pentanedione. We used continuous monitoring instruments to measure total volatile organic compounds, carbon monoxide, carbon dioxide, temperature, and relative humidity in specific areas and during tasks. We evaluated respiratory health and airborne exposures to alpha-diketones (diacetyl, 2,3-pentanedione, and 2,3-hexanedione), dust, other volatile organic compounds, carbon monoxide, and carbon dioxide during coffee roasting, grinding, flavoring, and packaging. Diacetyl and 2,3-pentanedione were detected in a majority of full-shift personal breathing zone air samples. During the November 2012 visit, the maximum concentration of diacetyl was 166.0 parts per billion in a personal sample from a packaging employee while the maximum 2,3-pentanedione concentration was 199.0 parts per billion from a personal sample collected on an employee in the flavoring room. In April 2017, personal samples from employees in the flavoring room gave maximum concentrations of 163.8 parts per billion diacetyl and 899.6 parts per billion 2,3-pentanedione. In November 2012, 58 of 59 full-shift personal samples exceeded the NIOSH recommended exposure limit for diacetyl of 5 parts per billion and 42 of 59 samples exceeded the NIOSH recommended exposure limit for 2,3-pentanedione of 9.3 parts per billion. In April 2017, 28 of 29 full-shift personal samples exceeded the NIOSH recommended exposure limits for diacetyl and 2,3-pentanedione. The production volume in April 2017 was approximately 70% higher than our first visit which likely contributed to the higher concentrations measured in some areas. During the medical survey, eye and nose symptoms were the most commonly reported symptoms; 1.6-fold excess of employees reported shortness of breath compared to the U.S. population with a similar demographic distribution, and 2.7 times as many employees as expected had spirometric obstruction than in the U.S. population. We recommend installing local exhaust and dilution ventilation and implementing administrative controls such as modification of work practices. Until engineering and administrative controls are in place, we recommend respiratory protection to reduce exposures to alpha-diketones. The choice of respirator should be guided by personal exposure sampling for diacetyl and 2,3-pentanedione and be made only by qualified personnel. We also recommended continuing the medical surveillance program. (Click to show less)
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(2020) Silica exposures during dowel drilling. (Click to open report)
Management from a dowel drilling company requested a NIOSH health hazard evaluation (HHE) concerning employee exposure to respirable crystalline silica during dowel drilling activities. Dowel drilling is one step in the process of repairing a road. The work on this HHE took place on a state road construction site. During our visit, we observed work processes and work practices, estimated the amount of water used to control dust, collected air samples for respirable crystalline silica and respira... (Click to show more) Management from a dowel drilling company requested a NIOSH health hazard evaluation (HHE) concerning employee exposure to respirable crystalline silica during dowel drilling activities. Dowel drilling is one step in the process of repairing a road. The work on this HHE took place on a state road construction site. During our visit, we observed work processes and work practices, estimated the amount of water used to control dust, collected air samples for respirable crystalline silica and respirable dust, and collected bulk samples of the slurry produced from drilling to determine its silica content. Our air sampling showed that the drill rig operation led to concentrations of respirable crystalline silica above relevant occupational exposure limits; however, the drill rig operator was wearing appropriate respiratory protection. Concentrations of respirable dust were below relevant occupational exposure limits for all samples. The slurry bulk samples contained 10%-13% quartz. The drill rig operator was required to wear a respirator, but there was no written respiratory protection program, medical clearance, or annual respiratory training. However, the respirator was put on and taken off correctly, cleaned after each shift, and stored appropriately. Other health and safety issues we identified during our evaluation included leaving the slurry and dust on the drill rig to dry overnight, high visibility vests not being used consistently, stepping into the live traffic lane while filling and covering patches, and not having enough vehicle spacing in between crews. We recommended developing a written respiratory protection program, sending drill rig operators for medical respirator clearance, and providing employees training about respirator use and maintenance. We also made recommendations to address other health and safety issues we identified during our evaluation. (Click to show less)
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(2019) Exposures and respiratory health at a coffee roasting and packaging facility and two off-site retail cafés. (Click to open report)
In March 2016, the National Institute for Occupational Safety and Health's Health Hazard Evaluation Program received a request from the owner of a coffee roasting and packaging facility and off-site retail cafés with 15 employees regarding concerns about exposures to and health effects from diacetyl and 2,3-pentanedione during coffee roasting, coffee grinding, and café tasks. In May 2017, we conducted the medical survey, industrial hygiene survey, and ventilation assessment at the roastery produ... (Click to show more) In March 2016, the National Institute for Occupational Safety and Health's Health Hazard Evaluation Program received a request from the owner of a coffee roasting and packaging facility and off-site retail cafés with 15 employees regarding concerns about exposures to and health effects from diacetyl and 2,3-pentanedione during coffee roasting, coffee grinding, and café tasks. In May 2017, we conducted the medical survey, industrial hygiene survey, and ventilation assessment at the roastery production space and two off-site retail cafés. The industrial hygiene survey consisted of collecting personal breathing zone and area air samples for alpha-diketones (i.e., diacetyl, 2,3-pentanedione, and 2,3-hexanedione). We used continuous monitoring instruments to measure total volatile organic compounds, carbon monoxide, carbon dioxide, temperature, and relative humidity in specific areas and during tasks. We also conducted a ventilation assessment in both cafés and the roastery production space location. The medical survey consisted of a health questionnaire and breathing tests. An interim letter reporting industrial hygiene results and recommendations was sent to the company following our visit. Most time-weighted average air concentrations of diacetyl and 2,3-pentanedione were below the NIOSH recommended exposure limits. Five of the 13 full-shift samples collected during the survey exceeded the NIOSH recommended exposure limit for diacetyl of 5 parts per billion, with a maximum concentration of 13.9 parts per billion. We identified jobs where some work tasks resulted in relatively higher air concentrations of diacetyl than other tasks. Specifically, grinding roasted coffee beans was associated with higher diacetyl levels. Overall, the most commonly reported symptoms were associated with mucous membranes, specifically the nose, eyes, and sinuses. Most employees reported that they did not feel that their symptoms were caused or aggravated by work-related exposures. Wheezing or whistling in the chest was the most commonly reported lower respiratory symptom, 33% of employees reported experiencing this symptom in the last 12 months. All administered spirometry tests (n=9) were normal. One of nine participants had high exhaled nitric oxide, a marker of allergic airways inflammation, and three of nine participants had airway obstructions. We recommend moving the cold brew grinders in the basement of the downtown café closer to an outside wall and installing an exhaust fan or ducted local exhaust ventilation system to exhaust contaminants generated during grinding directly outdoors. We also recommend introducing prescribed amounts of fresh, outdoor air to the café spaces to help further reduce airborne concentrations. Further, we recommended operating the ventilation system in the roastery production space continuously during roastery operating hours, training employees about workplace hazards, and establishing a medical monitoring program to identify any employees who may be developing work-related lung disease (e.g., asthma, obliterative bronchiolitis) and to help management prioritize interventions to prevent occupational lung disease. (Click to show less)
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(2019) Exposures and respiratory health concerns in a paper converting equipment manufacturing facility. (Click to open report)
In January 2012, the National Institute for Occupational Safety and Health received a confidential employee request for a health hazard evaluation at a paper tissue converting equipment manufacturing facility regarding concerns about lung disease and air quality, with exposures to coolants, oils, solvents, paper dust, exhaust fumes, welding and plasma cutting fumes, and lacquer thinner encountered during production activities. In June 2012, we toured the facility; interviewed employees, managers... (Click to show more) In January 2012, the National Institute for Occupational Safety and Health received a confidential employee request for a health hazard evaluation at a paper tissue converting equipment manufacturing facility regarding concerns about lung disease and air quality, with exposures to coolants, oils, solvents, paper dust, exhaust fumes, welding and plasma cutting fumes, and lacquer thinner encountered during production activities. In June 2012, we toured the facility; interviewed employees, managers, and the company's nurse; observed employees at work; assessed some of the mist collectors and vacuum pumps; and collected bulk samples of unused (neat) and in-use process fluids. Gram-negative bacteria, particularly Pseudomonas oleoverans/pseudoalcaligenes, were present in all in-use fluid samples ranging from 140 million colony forming units per milliliter to 1.4 billion colony forming units per milliliter. Concentrations of endotoxin, a component of gram-negative bacterial cell walls, in the fluid samples ranged from 3,001 endotoxin units per milliliter to 108,017 endotoxin units per milliliter. We identified four nonsmoking employees who had severe lung disease, including one employee who required lung transplantation. In response, we conducted medical record reviews and obtained reviews of lung tissue specimens for the four employees with severe lung disease. Lung tissue specimens from the employees, obtained by lung biopsy or at the time of lung transplantation, were reviewed by five pulmonary pathologists at three different institutions. The pathologists found the tissue samples demonstrated an unusual pattern of lung disease involving lymphocytic bronchiolitis with extension into alveolar ducts and emphysema. Chest computed tomography scans primarily demonstrated centrilobular emphysema. Spirometry demonstrated airways obstruction and that diffusing capacity of the lung for carbon monoxide was decreased, consistent with small airways disease and emphysema. In an effort to better understand what might have caused the cases of severe lung disease and to prevent future cases of illness, we conducted a detailed industrial hygiene survey in February 2013 and a medical survey in March 2013. The industrial hygiene survey involved collecting personal and area air samples for thoracic aerosol, metalworking fluids, and endotoxin; area air samples for bioaerosols, volatile organic compounds, and metals, and total particulate (collected with closed-face cassette) for microbiome analysis; real-time measurements of volatile organic compounds and size-selective particulate; collection of bulk process fluids for analysis of culturable bacteria, culturable fungi, endotoxin, and microbiome; and examination of the airflow using a safe tracer gas. The medical survey involved administering a health questionnaire and breathing tests to employees. In addition, a microbiome analysis of lung tissue specimens from the four employees with severe lung disease was performed. Local and state health officials, and physicians who worked in the local community, including a regional medical center and tertiary care referral center, were contacted regarding their awareness of other cases of this severe lung disease occurring in the surrounding region. During the 2013 survey, we identified a variety of processes with the potential to generate airborne exposures. For example, metals (steel [85-90%], aluminum [10-15%], and cast iron [less than 1%]) and plastics (less than 1%) were cut using saws, pressurized water, or plasma technology. Cut pieces were then processed into parts using grinders, mills, and lathes. Welding and painting were performed. Assembled machines were tested for functionality using customers' paper. We also found the facility used two metalworking fluids, preserved and non-preserved. The preserved metalworking fluid was designed for use with a bactericide and the non-preserved metalworking fluid did not require bactericide. Most process fluid bulk samples demonstrated growth of gram-negative bacteria, particularly Pseudomonas oleovorans/pseudoalcaligenes, at levels ranging from 70 colony forming units per milliliter to 57 million colony forming units per milliliter. Concentrations of endotoxin in the fluid samples ranged from 338 endotoxin units per milliliter to 390,633 endotoxin units per milliliter. Thoracic aerosol, metalworking fluids, metals, and volatile organic compounds were measureable in air at levels below occupational exposure limits and were highest in production areas. Two personal endotoxin samples from employees in the machine shop were above the Dutch Expert Committee on Occupational Safety (DECOS) recommended exposure limit of 90 endotoxin units per cubic meter (EU/m3). Assessment of the ventilation in the production area using a safe tracer gas demonstrated flow from the machine shop to the assembly area, highlighting opportunities for air contaminants in the machine shop area to reach assembly employees. Among current employees, some symptoms were more common than expected, while spirometric abnormalities were not in excess. Physicians and public health practitioners in the community and surrounding region had not observed cases of severe lung disease involving lymphocytic bronchiolitis with extension into alveolar ducts and emphysema occurring outside of employees at this facility. Lung tissue samples from the four employees with severe lung disease involving lymphocytic bronchiolitis with extension into alveolar ducts and emphysema were more enriched with Pseudomonas bacteria compared with lung tissue samples obtained from patients who did not work at the facility and underwent lung biopsies at the same nearby regional hospital. Because there was a cluster of workers with unusual lung disease, the cause of the lung disease was uncertain, and organized medical surveillance of the workforce was not in place, we conducted follow-up medical and industrial hygiene surveys in September 2016. The industrial hygiene survey consisted of collecting area air samples to analyze for thoracic aerosol, metalworking fluid and endotoxin, and bulk process fluid samples analyzed for culturable bacteria, culturable fungi, bacterial populations (microbiome) using molecular methods, and endotoxin. The medical survey consisted of a health questionnaire and breathing tests, and analysis of microbiome using molecular methods for samples taken from the skin, nose, and mouth of employees. The medical records for an additional employee identified as having severe lung disease were reviewed and lung tissue specimens were reviewed by the same five pathologists that had previously reviewed lung tissue from four employees. The overall concentrations of thoracic aerosol and extracted metalworking fluid in the air samples were lower during the 2016 survey compared with the 2013 survey. The installation of nine new mist collectors and the natural ventilation from open windows and bay doors might have contributed to the decrease in these concentrations. Pseudomonas oleoverans/ pseudoalcaligenes was the only type of gram-negative bacteria identified by culture with concentrations ranging from 370 colony forming units per milliliter to greater than 30 million colony forming units per milliliter. Endotoxin concentrations ranged from 35 endotoxin units per milliliter to 10,059 endotoxin units per milliliter. Microbiome analyses identified differences in the types of bacteria between the two types of metalworking fluids. Preserved metalworking fluid samples were enriched with different types of bacteria, including Brevundinomonas, Alcaligenaceae (u.g.), and Sphingobacterium. In contrast, non-preserved metalworking fluid samples were predominantly enriched with Pseudomonas. Among the total population of current employees who participated in the 2016 medical survey, the occurrence of wheeze in the last 12 months was more common than expected while spirometric abnormalities were not in... (Click to show less)
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