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HHE Search Results
282 HHE reports were found based on your search terms. Reports are listed in order of year published with the most recently published reports listed first.
Year Published and Title
(2024) Exposures and health concerns in a dental clinic. (Click to open report) Request: We received a management request for a health hazard evaluation at a dental clinic. The request stated concerns about idiopathic pulmonary fibrosis (IPF). IPF is a serious long term lung disease that can cause permanent scarring in the lungs. IPF was first identified in a cluster of dentists reported in 2018. In response to the request, we performed an air sampling survey in August 2022 to evaluate potential exposures to respirable dust, respirable crystalline silica, respirable metals,... (Click to show more)Request: We received a management request for a health hazard evaluation at a dental clinic. The request stated concerns about idiopathic pulmonary fibrosis (IPF). IPF is a serious long term lung disease that can cause permanent scarring in the lungs. IPF was first identified in a cluster of dentists reported in 2018. In response to the request, we performed an air sampling survey in August 2022 to evaluate potential exposures to respirable dust, respirable crystalline silica, respirable metals, and volatile organic compounds (VOCs). We also assessed the existing ventilation systems in the dental clinic. Workplace: The dental clinic provides dental care services to patients. General dentistry services and procedures are performed at the clinic and clinic laboratory. The dental clinic is housed on the second floor of a two-story medical clinic on an academic campus. At the time of our survey, eight staff were onsite, including two dentists, two dental hygienists, three dental assistants, and one administrative staff. Our Approach We conducted a site visit in August 2022 to assess possible exposures during routine dental care, assess the ventilation systems in use, and informally interview clinic staff. We conducted opening and closing meetings with employees and management to share background information about NIOSH and this health hazard evaluation. We also described the purpose of our survey, activities that would be performed while onsite, and actions that would be taken after we concluded our survey. During our onsite survey, we: a) Collected full-shift personal air samples on dental clinic employees for respirable dust and respirable crystalline silica. b) Collected full-shift area air samples in multiple locations in the dental clinic for respirable dust, respirable crystalline silica, respirable metals, and volatile organic compounds (VOCs). c) Collected instantaneous air samples for VOCs during various tasks and procedures. d) Collected real-time measurements of respirable aerosols in and just outside of the laboratory. e) Assessed the heating, ventilation, and air-conditioning (HVAC) systems in use. f) Informally interviewed clinic staff to learn about any health concerns potentially related to exposures at work. Our Key Findings: All personal air samples were below the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) and the American Conference of Governmental Industrial Hygienists (ACGIH®) threshold limit value (TLV®) for respirable dust. All personal air samples for respirable crystalline silica were below the NIOSH recommended exposure limit (REL) and OSHA PEL. All area air samples for respirable dust, respirable crystalline silica, and respirable metals were low; some metals were measured in all or most areas of the clinic. Some VOCs were higher in some locations or during specific tasks and procedures. Ethanol and isopropyl alcohol were the highest measurements collected during full-shift area sampling and during task or source sampling and were likely due to cleaning and disinfecting tasks. Treatment rooms (dental operatories) and staff offices did not receive adequate outdoor air from existing mechanical ventilation systems, and the clinic was unable to maintain temperatures in the clinic recommended by ASHRAE. LEV controls in the laboratory were not consistently used. When no LEV was used, higher levels of air contaminants were measured in the laboratory and adjacent hallway. Respirable aerosol generated in the laboratory migrated to adjacent areas. Employees reported no work-related symptoms. Our Recommendations: 1: Reduce risk of entrainment of air from the laboratory into adjacent spaces. 2: Encourage employees to utilize local exhaust ventilation (LEV) controls in the laboratory area during grinding, trimming, or soldering tasks. 3: Consider using LEV controls such as high-volume evacuation (HVE) and voluntarily using N95® filtering facepiece respirators (or other air-purifying particulate respirators) when performing dental procedures with nickel or silica (e.g., restorative procedures). 4: Improve ventilation so that all areas receive adequate outdoor air and maintain appropriate temperatures and comfortable humidity levels. 5: Make NIOSH-approved N95 filtering facepiece respirators (or other air-purifying particulate respirators) available for voluntary use and train employees on proper use of respiratory protection. 6: Ensure employees understand the hazards associated with working in a dental clinic and how to protect themselves. 7: Encourage employees to report any new, persistent, or worsening respiratory symptoms, particularly those with a work-related pattern, to their healthcare providers and, as instructed by their employer, to a designated individual at their workplace.
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(2020) Exposures and health concerns in a dental clinic. (Click to open report) Request: We received a management request for a health hazard evaluation at a dental clinic. The request stated concerns about possible exposure to mercury vapors from amalgam, a metal alloy used for dental fillings. Workplace: The dental clinic provides dental care services to patients. Services include general dentistry, family dentistry, cosmetic dentistry, restorative dentistry, full-mouth reconstruction, and oral surgery services. At the time of our survey, the clinic employed 17 staff, inc... (Click to show more)Request: We received a management request for a health hazard evaluation at a dental clinic. The request stated concerns about possible exposure to mercury vapors from amalgam, a metal alloy used for dental fillings. Workplace: The dental clinic provides dental care services to patients. Services include general dentistry, family dentistry, cosmetic dentistry, restorative dentistry, full-mouth reconstruction, and oral surgery services. At the time of our survey, the clinic employed 17 staff, including three dentists, dental hygienists, dental assistants, administrative staff, and a business administrator. In June 2019, we conducted a site visit to assess possible exposures during routine dental care, assess the ventilation systems in use, and informally interview clinic staff. During our survey in June 2019, we 1) Collected full-shift time-weighted average (TWA) samples on dental clinic employees while they performed their regular job duties and analyzed for elemental mercury content. 2) Collected full-shift TWA area samples in multiple locations in the dental clinic and analyzed for respirable dust, respirable silica, respirable metals, and volatile organic compound (VOC) concentrations. Full-shift TWA areas samples for VOCs were collected with two different samplers, placed side-by-side. 3) Collected instantaneous task-based and area air samples for VOCs during various tasks and procedures. 4) Assessed the heating, ventilation, and air-conditioning (HVAC) systems in use. 5) Informally interviewed clinic staff to learn about any health concerns potentially related to exposures at work. Our Key Findings: 1) All personal air samples for elemental mercury were below the NIOSH recommended exposure limit (REL) of 50 micrograms per cubic meter of air (ug/m3). 2) All area air samples for respirable dust, respirable silica, and respirable metals were low. 3) Some VOCs were higher in some locations or during specific tasks or procedures. 4) The laboratory area was under positive pressure relative to adjacent areas and could serve as a source of air contaminants. 5) Some employees reported eye and nose symptoms that were better when away from work. Our Recommendations: Recommendation 1: Reduce risk of entrainment of air from the laboratory into adjacent spaces. Recommendation 2: Encourage employees to minimize walking through the laboratory area while grinding or sandblasting tasks are being performed. Recommendation 3: Make N95 filtering-face piece respirators available for voluntary use and train employees on proper use of respiratory protection. Recommendation 4: Encourage employees to report any new, persistent, or worsening respiratory symptoms, particularly those with a work-related pattern, to their healthcare providers and, as instructed by their employer, to a designated individual at their workplace.
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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.
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(2019) Fire debris cleanup employees' exposure to silica, asbestos, metals, and polyaromatic hydrocarbons. (Click to open report) The NIOSH Health Hazard Evaluation Program received requests from construction company managers, representatives of two unions, and a government agency for the state of California concerning exposures to asbestos, heavy metals, respirable crystalline silica, and polyaromatic hydrocarbons during cleanup of structural debris and burn ash after wildfires spread into homes and business. When structures are destroyed by wildfires, hazardous materials may be left behind, which can impact workers clean... (Click to show more)The NIOSH Health Hazard Evaluation Program received requests from construction company managers, representatives of two unions, and a government agency for the state of California concerning exposures to asbestos, heavy metals, respirable crystalline silica, and polyaromatic hydrocarbons during cleanup of structural debris and burn ash after wildfires spread into homes and business. When structures are destroyed by wildfires, hazardous materials may be left behind, which can impact workers cleaning up the area, the public, and the surrounding environment. After a wildfire in 2018, our evaluation of fire debris cleanup included observation of work practices, employee interviews, review of previous exposure assessments during wildfire debris cleanup work, and measurement of airborne exposures to respirable crystalline silica, asbestos, metals, and polyaromatic hydrocarbons, and skin exposure to metals and polyaromatic hydrocarbons. Many of the fire debris cleanup employees we evaluated were exposed to respirable crystalline silica. Two skid steer operators were exposed to concentrations above the ACGIH threshold limit value and the OSHA action level. Employees exposures to airborne asbestos, metals, and polyaromatic hydrocarbons were well below exposure limits. Employees' hands had detectable amounts of metals on them; most of the skin wipes had nondetectable amounts of polyaromatic hydrocarbons. We observed inconsistent use of personal protective equipment. We also observed instances where dust suppression with water was not used. Although noise level measurement was not included in our assessment, noise from construction equipment could expose operators and laborers to noise levels above the NIOSH recommended exposure limit. To address the silica overexposures, we recommended consistently using water spray to reduce dust, developing a silica medical surveillance program, and educating employees on silica and silicosis. We recommended the construction companies ensure consistent and proper wear of personal protective equipment. Additional recommendations included (1) evaluating employees' noise exposures; (2) adding handwashing facilities; (3) requiring employees to wash their hands before eating, drinking, or smoking; and (4) discontinuing use of latex gloves.
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(2019) Silica exposures during drywall sanding. (Click to open report) The Health Hazard Evaluation Program received a request from the management of a drywall finishing company concerned with employee exposure to respirable crystalline silica during drywall-sanding activities. Our site visit consisted of observing work processes and practices, measuring the air velocity in the vacuum hose, collecting air samples for respirable crystalline silica and respirable dust, and collecting bulk samples of sanding dust to determine its silica content. Our air sampling found... (Click to show more)The Health Hazard Evaluation Program received a request from the management of a drywall finishing company concerned with employee exposure to respirable crystalline silica during drywall-sanding activities. Our site visit consisted of observing work processes and practices, measuring the air velocity in the vacuum hose, collecting air samples for respirable crystalline silica and respirable dust, and collecting bulk samples of sanding dust to determine its silica content. Our air sampling found overexposures to respirable dust, but no overexposures to respirable crystalline silica. However, there could be overexposures to respirable crystalline silica if sanding was performed for the entire day. Vacuums were sometimes used without a disposable bag and without emptying the vacuum canister before it was used at the start of the work shift. Sometimes vacuum filters were removed and tapped on the trash bin to dislodge dust. Although the company had a voluntary respiratory protection program, employees were not wearing their respirators correctly. We recommended the company conduct additional personal air sampling for respirable dust and silica as multiple days of sampling in a variety of work sites will provide more information about potential respirable dust exposures. We recommended improving vacuum care and maintenance practices including establishing clear guidelines for when to empty the vacuum, replace the vacuum cleaner bags, and replace filters. We also recommended the company strengthen their voluntary respiratory protection program.
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(2019) Silica exposures during micro trenching. (Click to open report) Management from a communications company requested a health hazard evaluation concerning employee exposure to respirable crystalline silica during micro trenching activities (process of cutting the roadway to install communication cable). During a given workday, employees performed tasks that included cutting the micro trench, installing the cable, emptying the vacuum truck, filling the micro trench, and loading the dumpster. Over a three-day period, we observed work processes and work practices... (Click to show more)Management from a communications company requested a health hazard evaluation concerning employee exposure to respirable crystalline silica during micro trenching activities (process of cutting the roadway to install communication cable). During a given workday, employees performed tasks that included cutting the micro trench, installing the cable, emptying the vacuum truck, filling the micro trench, and loading the dumpster. Over a three-day period, we observed work processes and work practices, collected air samples for respirable crystalline silica and respirable dust, collected bulk samples of the material being cut to determine its silica content, and measured the air velocity in the vacuum hose. We found low concentrations of respirable dust in the air; respirable crystalline silica was not detected. The vacuum truck appeared to control exposures. Emptying the vacuum and loading the dumpster produced the most dust. We found between 5.5% and 26% quartz in the bulk samples. Employees were not wearing their respirators correctly, and appeared to be unsure about proper donning and doffing techniques. Some employees had facial hair and did not recall being fit tested. We recommended the company explore other methods for loading the dumpster and cleaning the vacuum filter because these tasks caused the most dust, and potentially, the greatest risk of exposures. We made a number of recommendations on ways to improve the company respiratory protection program. We also recommended the company perform periodic noise monitoring to determine which job tasks require hearing protection as there appeared to be excessive noise generated when the saw and vacuum when both were operating together.
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(2018) A thermal drying process at a wastewater treatment plant. (Click to open report) The Health Hazard Evaluation Program received a request from employees at a wastewater treatment plant who were concerned about exposures to thermally dried sewage sludge. In particular, employees were concerned about odors, upper airway irritation, and dust exposures from the newly-installed thermal dryer. We reviewed the process flow and thermal dryer operations, collected air samples and bulk samples for endotoxins and silica, conducted confidential health interviews with employees, and revie... (Click to show more)The Health Hazard Evaluation Program received a request from employees at a wastewater treatment plant who were concerned about exposures to thermally dried sewage sludge. In particular, employees were concerned about odors, upper airway irritation, and dust exposures from the newly-installed thermal dryer. We reviewed the process flow and thermal dryer operations, collected air samples and bulk samples for endotoxins and silica, conducted confidential health interviews with employees, and reviewed records. Exposures to endotoxins and silica were low. Dust and odors were detected throughout the facility. We surveyed employees about work-related symptoms related to working with a new thermal sewer sludge dryer. The most common health symptoms reported by employees were eye irritation, coughing, nasal congestion, and headaches. Strong odors were reported by employees during the treatment process. We observed potential fire hazards in the thermal dryer area because dryer conditions led to overheating of sludge and the presence of combustible dust. We observed that respirators were not always used, maintained, or stored correctly. In addition, correct use of other personal protective equipment such as gloves and safety glasses was inconsistent. We recommended the company work with the thermal dryer manufacturer to ensure that the equipment is working according to design and all safety mechanisms are operational; ensure that respirators are properly worn, maintained, and stored, and employees are trained on how to use them; and improve the personal protective equipment use and compliance.
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(2018) Health hazard evaluation report: evaluation of lead and isocyanate exposure in a maintenance facility with small arms repair and vehicle painting shops. (Click to open report) The Health Hazard Evaluation Program received a request from a small arms repair and vehicle maintenance facility. A manager was concerned about airborne lead and take-home lead exposures in the small arms repair shop as well as employees' exposures to hazardous painting products, including isocyanates in the military vehicle painting shop. To evaluate employee exposures to lead we collected personal air, hand, and surface wipe samples and we evaluated blood lead levels. For isocyanates, we coll... (Click to show more)The Health Hazard Evaluation Program received a request from a small arms repair and vehicle maintenance facility. A manager was concerned about airborne lead and take-home lead exposures in the small arms repair shop as well as employees' exposures to hazardous painting products, including isocyanates in the military vehicle painting shop. To evaluate employee exposures to lead we collected personal air, hand, and surface wipe samples and we evaluated blood lead levels. For isocyanates, we collected personal air samples for hexamethylene diisocyanate and tested the employees' blood to look for isocyanate exposure and sensitization. We evaluated the ventilations systems in both areas. Although we detected no lead in the personal air samples, we did find lead on employees' hands after they had washed them, and one elevated blood lead level. We found hexamethylene diisocyanate in the air in the spray paint shop, and one employee had a blood test, which showed antibodies to a specific isocyanate (isophorone diisocyanate) in the paint, confirming recent exposure. We observed multiple opportunities for dermal exposure to paints that contained isocyanates. The firing line of the range had turbulent airflow, creating irregular mixing of air. The spray paint booth had missing and damaged filters and did not adequately remove paint overspray from the breathing zone of employees. We recommended the employer start an isocyanate medical surveillance program, use a lead removal product for hand washing and cleaning work surfaces, and have employees wear nitrile gloves while repairing firearms. We also recommended the employer provide eye and face protection and appropriately-sized protective suits for spray painting vehicles. Ventilation recommendations included reducing firing line turbulence and replacing the spray paint booth with a downdraft ventilation paint booth.
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(2017) Health hazard evaluation report: evaluation of exposure to crystalline silica, welding fume, and isocyanates during water heater manufacturing. (Click to open report) The Health Hazard Evaluation Program received a union request about employees' exposures to silica during tank finishing operations, welding fume during tank fabrication, and methylene diphenyl diisocyanate (MDI) during tank insulation using a spray foam application. We measured exposure to airborne crystalline silica, welding fume, and MDI, held medical interviews, administered medical questionnaires, and collected blood for biomarkers of isocyanate exposure and sensitization. We found overexpo... (Click to show more)The Health Hazard Evaluation Program received a union request about employees' exposures to silica during tank finishing operations, welding fume during tank fabrication, and methylene diphenyl diisocyanate (MDI) during tank insulation using a spray foam application. We measured exposure to airborne crystalline silica, welding fume, and MDI, held medical interviews, administered medical questionnaires, and collected blood for biomarkers of isocyanate exposure and sensitization. We found overexposure to crystalline silica during brushing, tank and flue spraying, and mill room operations. Methylene diphenyl diisocyanate and welding emissions were below occupational exposure limits. Employees reported symptoms consistent with work-related asthma. Two employees had MDI-specific IgE, consistent with MDI asthma, in their blood. Five employees had MDI-specific IgG in their blood, indicating recent exposure to MDI despite the use of engineering controls and personal protective equipment. Some employees in foam booths cut slits in their Tyvek suit to aid in cooling, creating a potential for skin exposure to MDI. Some ventilation controls were either not working or were ineffective in containing airborne contaminants. Improvements in ventilation system design, use, and maintenance are needed. The employer should also begin a medical surveillance program for employees exposed to MDI and silica and provide training on the hazards of working with both.
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(2016) Health hazard evaluation report: evaluation of crystalline silica exposure during fabrication of natural and engineered stone countertops. (Click to open report) The Texas Department of State Health Services asked the Health Hazard Evaluation (HHE) Program for help. They asked us to evaluate silica exposure in a manufacturing plant. The plant makes natural and engineered stone countertops. We measured employees' exposures to crystalline silica. We evaluated ventilation systems and personal protective equipment use. Employees used wet methods to help control dust. We found respirable crystalline silica in the air. Concentrations ranged from nondetectable ... (Click to show more)The Texas Department of State Health Services asked the Health Hazard Evaluation (HHE) Program for help. They asked us to evaluate silica exposure in a manufacturing plant. The plant makes natural and engineered stone countertops. We measured employees' exposures to crystalline silica. We evaluated ventilation systems and personal protective equipment use. Employees used wet methods to help control dust. We found respirable crystalline silica in the air. Concentrations ranged from nondetectable to 140 micrograms per cubic meter (ug/m3). Respirable dust concentrations ranged from nondetectable to 380 ug/m3. The percentage of quartz in these samples ranged from less than 1% to 52%. We found overexposures to crystalline silica despite the use of wet methods. None of the work processes used local exhaust ventilation. We saw some employees incorrectly using respirators, safety glasses, and ear plugs. The company did not have an employee medical surveillance program for silica. HHE Program investigators recommended using a combination of local exhaust ventilation and wet methods to control dust.
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