Health Hazard Evaluations (HHEs)

(2003) ChemDesign Corporation, Fitchburg, Massachusetts. (Click to open report)
On December 13, 1999, the National Institute for Occupational Safety and Health (NIOSH) received a request for Technical Assistance (TA) from the Massachusetts Department of Public Health, Occupational Health Surveillance Program (OHSP). OHSP asked NIOSH to conduct a health hazard evaluation (HHE) at ChemDesign Corporation in Fitchburg, Massachusetts, to investigate a cluster of eight occupational asthma cases which had been reported to OHSP. The chemicals associated with the cases were identifi... (Click to show more) On December 13, 1999, the National Institute for Occupational Safety and Health (NIOSH) received a request for Technical Assistance (TA) from the Massachusetts Department of Public Health, Occupational Health Surveillance Program (OHSP). OHSP asked NIOSH to conduct a health hazard evaluation (HHE) at ChemDesign Corporation in Fitchburg, Massachusetts, to investigate a cluster of eight occupational asthma cases which had been reported to OHSP. The chemicals associated with the cases were identified as AMT (3-amino-5-mercapto-1,2,4-triazole) and DE-498 (Flumetsulam). AMT was raw material used in the production of DE-498 and AMT-based product two (AMTBP2). In response to the request, NIOSH investigators, accompanied by an OHSP industrial hygienist, conducted an initial site visit to ChemDesign on February 1-3, 2000. The NIOSH industrial hygienist returned on June 5-9 to conduct air sampling at four routine operations where employees could be exposed to AMT or DE-498: (1) charging AMT powder into a reactor vessel, (2) discharging DE-498 "wet cake" from a centrifuge, (3) charging DE-498 into the dryer, and (4) discharging DE-498 from the dryer. On July 6-7, the NIOSH Project Officer and medical team visited ChemDesign to recruit workers for participation in a medical survey. On June 12-16, the team conducted a medical evaluation of volunteer production workers. The onsite medical evaluation consisted of a questionnaire interview, lung function testing, and a blood sample collection. A methacholine challenge test was administered at Burbank Hospital in Fitchburg, Massachusetts. In August 2000, NIOSH obtained copies of company medical records for the workers who signed a medical records release form. Environmental monitoring found quantifiable concentrations of AMT or DE-498 in personal breathing zone (PBZ) air samples during tasks where these materials were manually added to, or discharged from the closed system in Building 16. The greatest potential for exposure to these materials existed during these specific tasks. Although use of respiratory protection and other personal protective equipment (PPE) appeared to provide substantial protection, reports of upper respiratory symptoms by several employees with occupational asthma (OA) indicate that PPE may not provide adequate protection for these individuals. Visible airborne dust during AMT and dryer charges, indicates a need for improved engineering controls (local exhaust ventilation) to reduce the potential for worker exposures. AMT and DE-498 in area air samples collected at the boundaries of restricted areas established during reactor and dryer charging, ranged from below the limit of detection to barely quantifiable levels. Changes in work practices, PPE, and engineering controls during the various production campaigns preclude assessment of the nature and extent of previous exposures to AMT and DE-498. A total of 41 employees and four former employees participated in the medical survey; the participation rate was 41% in production workers with a potential for AMT exposure. The medical survey identified 12 cases of physician-diagnosed asthma that were diagnosed after the cases started working at ChemDesign. In 11 of these, the onset corresponded with periods when AMT was used in the company. The physician's diagnosis of OA was mostly made on the basis of the presence of nonspecific bronchial hyperreactivity (NSBH), work-related respiratory symptoms, and in some cases work-related serial peak flow changes. The NSBH occurred after a latency period; allergy to common allergens was not a risk factor for the development of OA in these cases. Laboratory studies were undertaken to assess whether the respiratory symptoms observed in ChemDesign workers could be due to an allergic response to AMT and DE-498. Studies done on human blood of employees exposed to AMT were not able to clearly demonstrate that AMT or DE-498 exposures were associated with an allergic response to those agents. However, animal studies clearly show that AMT, but not DE-498, is capable of causing an allergic response. The results from the animal studies support the original complaints that AMT caused occupational asthma. However, the possible role of DE-498 cannot be excluded from negative animal studies. A large percentage of employees reported respiratory symptoms that started during 1998, when two new campaigns using AMT were started in ChemDesign. However, apart from AMT, other agents were reported as causing or making the respiratory symptoms worse. Chronic lung function effects were also found. A high percentage of the participants (18%) had mild airflow obstruction according to the American Thoracic Society (ATS) criteria. The cross-sectional analysis of the lung function measurements done by NIOSH showed significant decrease in Forced Expiratory Volume in one second (FEV1) and in the ratio of FEV1 and Forced Vital Capacity (FVC), FEV1/FVC: this pattern is suggestive of airway obstruction. The data analysis of company yearly lung function data confirmed that the study participants had a higher mean decline in FEV1 and FEV1/FVC with age, than would be expected from the reference equations. In summary, the results of the medical and laboratory investigation provide evidence that the incidence of OA was associated with exposure to AMT. There was an association between AMT exposure and asthma onset, NSBH associated with AMT exposure improved after withdrawal from AMT exposure, and AMT was found to be a sensitizer in animal studies. The findings show that ChemDesign employees are exposed to agents that can lead to occupational asthma and steeper decline in lung function with age than would be expected. Respiratory symptoms and lung function monitoring currently done at ChemDesign provide an opportunity to utilize the data for the protection of employees' respiratory health. Active workers' participation in the respiratory health protection program should be encouraged. Investigators examined changes in yearly thyroid hormone (T4) measurements in relation to working on the AMT campaigns. The possibility that AMT was associated with the decrease in thyroid hormone production could not be ruled out because of insufficient data. The investigation provides strong evidence that AMT (3-Amino-5-mercapto-1,2,4-triazole) was the causal agent responsible for the cluster of occupational asthma that occurred in ChemDesign. AMT has a potential for causing allergic response in experimental animals. Environmental monitoring found quantifiable concentrations of AMT in personal breathing zone air samples collected during routine production. Study participants had a high frequency of work-related respiratory symptoms whose onset corresponded with the use of AMT. The group of study participants had decreased mean pulmonary function values suggestive of airflow obstruction, identified from cross-sectional and longitudinal data. The findings of this study show that ChemDesign employees are exposed to chemical agents that can lead to occupational asthma and to COPD. Therefore effective exposure controls and a pulmonary function monitoring program need to be implemented and maintained to prevent further occurrence of respiratory disease in the employees. (Click to show less)
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(2003) Fayette County Courthouse, Uniontown, Pennsylvania. (Click to open report)
In July 2002, the National Institute for Occupational Safety and Health (NIOSH) received a request for a health hazard evaluation (HHE) from employees at the Fayette County Courthouse in Uniontown, Pennsylvania. Employees had reported a variety of health concerns: headaches, nausea, tiredness, nasal and sinus symptoms, vomiting, burning eyes, sore throats, breathing problems, coughing, ear infections, and dizziness. The employees reported strong and unpleasant odors from the carpeting, old pa... (Click to show more) In July 2002, the National Institute for Occupational Safety and Health (NIOSH) received a request for a health hazard evaluation (HHE) from employees at the Fayette County Courthouse in Uniontown, Pennsylvania. Employees had reported a variety of health concerns: headaches, nausea, tiredness, nasal and sinus symptoms, vomiting, burning eyes, sore throats, breathing problems, coughing, ear infections, and dizziness. The employees reported strong and unpleasant odors from the carpeting, old papers, and dirty ceiling tiles; poor air quality; lack of airflow; stale water; mold, fungus, and mildew; asbestos; excessive dust; and dampness. All of the concerns involved the basement and first floors of both the original courthouse and annex buildings. On August 28, 2002, NIOSH investigators completed a preliminary site walkthrough evaluation. Medical interviews and an environmental investigation were conducted in October of 2002. The environmental investigation revealed a number of locations in the courthouse that may have had mold growth due to water incursion or leakage. The ventilation systems in most of the basement and first floors were inadequate (i.e., air changes and the amount of fresh air entering the offices did not meet the American Society of Heating, Refrigerating, and Air-Conditioning Engineers [ASHRAE] minimum requirements). Temperature, relative humidity, carbon dioxide and carbon monoxide levels were largely within recommendations in all monitored areas. The levels for volatile organic compounds were generally below established exposure limits. The ventilation systems should be upgraded to meet ASHRAE recommendations. Water leaks should be repaired and damaged ceiling tiles and walls should be replaced with care to ensure that any generated dust does not enter occupied sections of the building. Interviewed office workers reported respiratory symptoms consistent with asthma with onset after the date of hire. Environmental assessment demonstrated insufficient ventilation, mold growth, and water incursion in the building. (Click to show less)
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(2003) Letter to Nebraska Popcorn, Clearwater, Nebraska. (Click to open report)
While our lung function tests of workers at your plant did not reveal obstruction, the abnormality most associated with butter flavoring exposure, this should not be interpreted to mean that there is little, or no risk from flavoring exposure in your plant. As I discussed in my previous letter, while most of your microwave production workers had lung function that was in the normal range, it is possible that some had higher levels of function in the past. The respiratory symptoms reported by som... (Click to show more) While our lung function tests of workers at your plant did not reveal obstruction, the abnormality most associated with butter flavoring exposure, this should not be interpreted to mean that there is little, or no risk from flavoring exposure in your plant. As I discussed in my previous letter, while most of your microwave production workers had lung function that was in the normal range, it is possible that some had higher levels of function in the past. The respiratory symptoms reported by some of them may mean that their lung function could become abnormal in the future. In addition, since not all workers are equally susceptible to the effects of a chemical exposure, it is possible that the small number of workers we tested at your plant did not include workers that were sensitive to the air concentrations of flavoring chemicals that were present during our evaluation. Future new employees could be at risk, and changes in your production process, level of production, or the flavorings that you use could increase risk for current workers if exposures to flavorings chemicals increase as a result. (Click to show less)
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(2003) Somerset County Assistance Office, Somerset, Pennsylvania. (Click to open report)
The National Institute for Occupational Safety and Health (NIOSH) received a request for a health hazard evaluation from employees of the Somerset County Assistance Office (SCAO) in November 2000. The request included health complaints (sinus infections, breathing problems, bronchial infections, chronic fatigue, muscle aches, and irritation of throat, nose and eyes) and environmental concerns about water incursion and malfunction of ventilation. At the time of the request, there had been four ... (Click to show more) The National Institute for Occupational Safety and Health (NIOSH) received a request for a health hazard evaluation from employees of the Somerset County Assistance Office (SCAO) in November 2000. The request included health complaints (sinus infections, breathing problems, bronchial infections, chronic fatigue, muscle aches, and irritation of throat, nose and eyes) and environmental concerns about water incursion and malfunction of ventilation. At the time of the request, there had been four reported cases of hypersensitivity pneumonitis (HP) and eight reported cases of doctor-diagnosed asthma among a staff of 68 employees. In response to the request, NIOSH investigators conducted an initial walk-through survey in March 2001. The results of sample analyses and the screening questionnaire from the initial survey suggested possible biological contamination of the building and adverse respiratory effects. A second visit was planned and conducted from July 25 through August 15, 2001, to conduct environmental sampling, a heating, ventilating, and air conditioning (HVAC) inspection, medical testing, and a more extensive questionnaire survey. In December 2001, SCAO relocated their employees to a newly constructed building. The objectives of the second visit were to assess potential fungal contamination in the building and exposure levels of occupants, to characterize respiratory symptoms among occupants, to objectively test occupants' pulmonary function, and to examine the association of symptoms and medical test results with environmental exposure. For those aims, we conducted an interviewer-administered questionnaire survey, objective medical tests (spirometry and methacholines challenge tests, carbon monoxide diffusion capacity test, and exhaled nitric oxide measurements), and environmental measurements for microbial contaminants (culturable fungi, spore counts, endotoxin, ergosterol, and (1-->3)-ß-D-glucan), and evaluation of the HVAC system during the survey period. The participation rate was 93% for the screening questionnaire and 59% for the main questionnaire. There were 62 participants in the screening questionnaire survey and 15% reported asthma, 10% HP, and 36% any chest symptoms (wheeze, chest tightness, or shortness of breath in the past 4 weeks). Work-relatedness was reported by about 61% of the symptomatic people with one or more lower-respiratory symptoms (cough, wheeze, chest tightness, shortness of breath in the past 4 weeks). There were 40 participants in the main questionnaire survey and shortness of breath was reported by 52%, chest tightness by 40%, wheezing by 38%, and coughing for three consecutive months in the past 12 months by 25%. Up to 60% of the symptomatic people with the lower respiratory symptoms reported work-relatedness. Ninety-two percent of the participants in the main survey reported nasal symptoms and 90% reported sinus symptoms. In our study, we defined a case of probable work-related HP as a building occupant who reported one or more work-related (getting better away from work) lower respiratory symptoms (cough, wheeze, shortness of breath, and chest tightness) AND one or more systemic symptoms (fever/chills, flu-like/muscle achiness, weight loss of 10 pounds or more). From the questionnaire we identified 11 probable work-related HP cases. Note, however, that only 4 of these 11 symptomatic individuals were diagnosed as having HP by their physicians. We found two employees with borderline airways obstruction from our objective pulmonary function tests. One participant had mildly elevated exhaled nitric oxide. Three employees had low vital capacity with normal total lung capacity. No participants had test results indicating airways hyperresponsiveness or difficulties in gas transfer in the lungs. Our environmental investigation showed that the count of total airborne fungal spores (geometric mean=20,654 spores/m3) was about 60 times higher outdoors than indoors (geometric mean=348 spores/m3). A total of twenty fungal genera were identified in 180 indoor spore trap samples, and Cladosporium, basidiospores, and Epicoccum were the most frequently identified fungi indoors and outdoors. The level of total culturable airborne fungi (geometric mean=1,224 colony forming units (CFU)/m3) was about 10 times higher outdoors than indoors (geometric mean=123 CFU/m3). A total of 55 species of culturable fungi were identified in indoor air samples, and only 15 species were identified in outdoors samples. Both airborne spore counts and culturable fungi data showed different fungal composition between indoors and outdoors which implies that the SCAO indoor environment is likely to have had indoor sources of fungal contamination. However, we did not observe visible sources of fungal contamination within the occupied spaces at the time of investigation. Stachybotrys chartarum was found in 7 chair dust samples, but not in floor and air samples. In air, floor and chair dust samples, a total of 77 fungal species were identified, and air showed the most diverse range of fungal species. Our indoor monitoring data for relative humidity, temperature, carbon dioxide, and particles, along with bioaerosol measures, clearly showed variation of those parameters in association with human activity. Occupants were exposed to more bioaerosol and particles toward the end of the workweek. The levels of indoor carbon dioxide were lower than the recommended level (1,000 ppm, which is 700 ppm plus the outdoor level) from ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers)1; temperature during the survey period ranged from 70 to 80 degrees F and relative humidity ranged from 43 to 55%, both of which are within the recommended ranges for comfort and minimizing microbial growth (68-77oF and 30-60% relative humidity). Although our analyses were limited by a possible participation bias and by the small number of subjects participating in the study, we found a significant association of (1-->3)-ß-D-glucan level as a surrogate for fungal level in chair dust with usual cough using multivariate logistic regression analysis adjusting for age, gender, and atopic status. Airborne ergosterol, a surrogate measure for airborne fungi, was significantly associated with self-reported asthma after adjusting for gender. In our interim report on the NIOSH investigation of the HVAC system (see Appendix A), we recommended the remediation of roof leaks and problems with the HVAC system. Based on our HVAC evaluation and on the health evaluations described above, we make the following recommendations to SCAO, the previous building managers, and the SCAO employees. We recommend that the SCAO manager take the following actions: 1. Replace or clean the water-damaged furniture which may have been brought from the evaluated building to current SCAO offices. We recommend that employees take the following actions: 1. Consult a doctor for persistent or work-related lower respiratory symptoms such as wheeze, chest tightness, shortness of breath and/or cough or a combination of work-related lower respiratory symptoms and systemic symptoms (such as fever/chill, flu-like/muscle achiness, weight loss of 10 pounds or more). Objective medical tests can help your doctor diagnose the respiratory condition and its severity, and may help establish that it is work-related. We recommend that the manager of the evaluated building take the following actions to protect future tenants: 1. Fix or renovate areas with water incursion (roof, walls, and floor). Especially, repair the damaged roof to prevent condensed water from the air handling units (AHUs) from leaking through the roof. 2. Redirect the drainage from the AHU drain traps directly to the gutter, at least until the damaged roof is completely repaired. 3. Replace any water damaged building materials and water-stained carpet or ceiling tiles. 4. Inspect int... (Click to show less)
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(2003) The Concrete Revolution, Denver, Colorado. (Click to open report)
The National Institute for Occupational Safety and Health (NIOSH) received a management request from The Concrete Revolution in Denver, Colorado, to evaluate potential occupational exposure hazards in the manufacture of custom concrete counter tops. Five site visits were made to the plant between April and October 2002. Exposure assessments were conducted for noise, respirable crystalline silica, respirable dust (or particulates not otherwise regulated, respirable fraction), and asbestos fibers.... (Click to show more) The National Institute for Occupational Safety and Health (NIOSH) received a management request from The Concrete Revolution in Denver, Colorado, to evaluate potential occupational exposure hazards in the manufacture of custom concrete counter tops. Five site visits were made to the plant between April and October 2002. Exposure assessments were conducted for noise, respirable crystalline silica, respirable dust (or particulates not otherwise regulated, respirable fraction), and asbestos fibers. Full shift exposures to noise were less than the NIOSH recommended exposure level of 85 decibels on the A-weighted scale. Personal breathing zone (PBZ) exposures to respirable crystalline silica (as quartz and cristobalite) were below the limit of detection (LOD) for quartz in one sample and at trace concentrations [between the LOD and the limit of quantitation (LOQ)] for five other samples. Cristobalite was never detected above the LOD nor were airborne asbestos fibers. Certain elements (metals) were detected in samples of settled dusts from drying rooms 1 and 2 but were in very low concentrations. Quartz was also detected in settled dust samples in concentrations of 2.0 to 3.3%. Three area and six PBZ air samples collected for respirable dust ranged in concentration from 1.8 to 10 milligrams per cubic meter of air (mg/m3). One of these samples exceeded the OSHA Permissible Exposure Limit for respirable dust of 5 mg/m3. At the time of the NIOSH survey, management and employees at the Concrete revolution were refining work practices and considering modifications to exhaust ventilation in the drying rooms to reduce particulate exposures. Work practice, housekeeping, and ventilation recommendations are provided on pages 6-7 of this report. Occupational exposure to noise, respirable crystalline silica, asbestos and metals were all below established occupational health criteria at the time of this survey. One of nine samples for respirable dust exceeded the Occupational Safety and Health Administration (OSHA) criterion of 5 milligrams per cubic meter of air as an 8-hour time-weighted average. Recommendations are provided to modify work practices and consider ventilation changes to better control dusts while patching and finishing custom concrete counter tops. (Click to show less)
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