Health Hazard Evaluations (HHEs)

(2009) Employees' chemical exposures while blending and repackaging glass beads for road markings. (Click to open report)
On October 16, 2007, NIOSH received a confidential employee request for an HHE at Weissker Manufacturing (Weissker) in Palestine, Texas. Employees were concerned about exposures to lead, arsenic, formaldehyde, and dust while handling reflective glass beads. Health problems listed on the request and attributed to the dust from the glass beads included glassy eyes, sore throat, body aches, and flu-like symptoms. Weissker imported the glass beads in Super Sack containers (2200-pound capacity fabric... (Click to show more) On October 16, 2007, NIOSH received a confidential employee request for an HHE at Weissker Manufacturing (Weissker) in Palestine, Texas. Employees were concerned about exposures to lead, arsenic, formaldehyde, and dust while handling reflective glass beads. Health problems listed on the request and attributed to the dust from the glass beads included glassy eyes, sore throat, body aches, and flu-like symptoms. Weissker imported the glass beads in Super Sack containers (2200-pound capacity fabric bags) from Russia and China and repackaged the beads for resale. Both the Chinese and Russian glass beads had a silane coating. Employees complained about a fish-like odor emitted from the Chinese beads when they were wet. The odor may have come from the amines in the glass beads' coating. Weissker is no longer purchasing beads from China due to employees' health concerns. At the time of this evaluation six employees at Weissker worked one 8-hour shift. During our site visit on January 22-24, 2008, we observed the blending and repackaging process, reviewed the MSDSs for the glass beads, and interviewed employees. We also collected PBZ air samples for respirable dust, crystalline silica, elements (including arsenic and lead), and formaldehyde and GA air samples for total dust, formaldehyde, and elements. We analyzed bulk samples of glass beads for elements, VOCs, and size. We took wipe samples from employees' hands and work surfaces and had them analyzed for elements. Our review of the OSHA 300 Logs of Work-Related Injuries and Illnesses revealed that an employee was injured in June 2007, when his arm was trapped between a metal bin and a Super Sack while he was emptying it. All air sampling results were below applicable OELs. No VOCs were detected in the bulk samples of glass beads. Elements were either not detected or were detected at very low concentrations. Particle size analysis of the glass beads revealed that they were too large to be deposited in the respiratory tract or the lungs. We measured very low levels of elements on employees' hands, on work surfaces, and on the lunchroom table. We conducted confidential medical interviews with five employees; some reported eye and throat irritation. We recommend that employees wear safety glasses or goggles to prevent glass beads from getting in their eyes and that they wash their hands before eating or touching their face. We also recommend that employees not place their arms underneath the Super Sack containers when they are being emptied to prevent hand and arm injuries. (Click to show less)
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(2009) Exposures in sculpture studios at a college art department. (Click to open report)
NIOSH received a confidential employee request for an HHE at Brooklyn College in Brooklyn, New York. The request was to investigate health and safety concerns in the sculpture studios, including the ceramic, woodworking, and metalworking studios. Employees were concerned that degenerative nerve damage, lung cancer, sinus problems, allergies, and headaches were possibly related to work exposures. On October 22-24, 2007, NIOSH investigators conducted an initial evaluation that included an opening ... (Click to show more) NIOSH received a confidential employee request for an HHE at Brooklyn College in Brooklyn, New York. The request was to investigate health and safety concerns in the sculpture studios, including the ceramic, woodworking, and metalworking studios. Employees were concerned that degenerative nerve damage, lung cancer, sinus problems, allergies, and headaches were possibly related to work exposures. On October 22-24, 2007, NIOSH investigators conducted an initial evaluation that included an opening conference, a tour of the three sculpture studios, observations of work activities, and a review of relevant health and safety documents. We evaluated the ventilation in the studios, collected area and PBZ air samples for VOCs in the woodworking studio, and interviewed employees about their health. On October 24, we held a closing conference to provide preliminary recommendations. On March 28, 2008, we returned to collect area and PBZ welding fume air samples during a metalworking class. We observed inadequate electrical grounding, machine guarding, and spacing around power tools and machines; and poor housekeeping practices. Eating and drinking were allowed in the studios during classes, eye protection was not always used, and respirators were used improperly. Many of the existing health and safety rules and guidelines of the studios were not being enforced. The ventilation system did not mechanically provide supply air to the sculpture studios. PBZ air samples collected for VOCs showed that xylene (0.23 ppm) and toluene (0.04 ppm) were the only compounds measured at quantifiable levels, and their concentrations were well below the NIOSH REL (100 ppm for both xylene and toluene), the OSHA PEL (xylene: 100 ppm; toluene: 200 ppm), and the ACGIH TLV (xylene: 100 ppm; toluene: 20 ppm). All other VOCs were found at trace levels or were not detected. Of the 31 airborne metals and minerals analyzed from welding fumes, most were either not detected or were present at trace concentrations. Six elements were measured in quantifiable concentrations in at least three locations. Zinc was measured in the highest concentration on a PBZ sample of 150 microg/m3. This concentration was well below the NIOSH REL (5000 microg/m3) and the ACGIH TLV (2000 microg/m3) for zinc. All interviewed employees reported concerns about safety issues in the studios. Employees reported past exposures including cadmium, lead, and asbestos exposure in the metalworking studio in the 1980s and unventilated kiln exhaust in the ceramics studio 10 to 12 years ago. Employees reported current use of glues, including methylene chloride, in the woodworking studio. Most studio employees reported intermittent nose and throat irritation, and one reported intermittent headaches at work. Employees also reported concerns about dust exposure, inadequate ventilation, and high noise levels, particularly in the woodworking and metalworking studios. Some employees were also concerned about the risk of developing lung cancer and nervous system disorders from past and current work exposures and reported previous cases in retired faculty. Based on our findings, we conclude that employee reports of nose and throat irritation during work are consistent with particulate and/or irritant exposures. Although the VOCs and solvent levels we measured were below relevant OELs, some employees may still experience symptoms below the OELs. We determined that the neurological disorders and lung cancer in retired studio employees could not be properly assessed due to lack of historical records of exposure, inability to recreate past exposures, and small numbers of cases, making analysis not meaningful. Management should address the sculpture studios' safety issues and improve the ventilation system. The ventilation system should supply adequate outdoor air and provide sufficient make-up air when the hoods and kilns are in use. Although welding fume concentrations were below relevant OELs for specific constituents, NIOSH considers welding fumes a potential human carcinogen and recommends reducing exposures to the lowest feasible level. Management can reduce welding fume exposures by installing adjustable LEV that removes contaminants from the point of generation. Also, ventilation fans and dust collectors that were previously installed to help collect and reduce airborne contaminants should be used when welding or performing dust-generating tasks. We also recommend that management enforce safety rules and improve housekeeping practices. (Click to show less)
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(2009) Report on an investigation of asthma and respiratory symptoms among workers at a soy processing plant. (Click to open report)
On December 12, 2006, the National Institute for Occupational Safety and Health (NIOSH) received a confidential Health Hazard Evaluation (HHE) request from workers at the Solae Company's plant in Memphis, Tennessee. The requesters described respiratory symptoms and diagnoses, including sinus congestion and asthma, which they attributed to the workplace. They noted exposure to soy materials, lime (calcium oxide (CaO)), microbial contaminants such as mold, and insects. NIOSH investigators conducte... (Click to show more) On December 12, 2006, the National Institute for Occupational Safety and Health (NIOSH) received a confidential Health Hazard Evaluation (HHE) request from workers at the Solae Company's plant in Memphis, Tennessee. The requesters described respiratory symptoms and diagnoses, including sinus congestion and asthma, which they attributed to the workplace. They noted exposure to soy materials, lime (calcium oxide (CaO)), microbial contaminants such as mold, and insects. NIOSH investigators conducted telephone interviews with workers, a union representative, treating physicians, and company management and safety officials. On March 6, 2007, NIOSH investigators visited the plant to observe the process, measure concentrations of airborne dust, collect bulk samples of soy materials, and interview workers about their symptoms and exposures. They later conducted an industrial hygiene survey (July 9-13 and July 30-August 3, 2007). NIOSH investigators collected personal and area air samples from different plant areas, sub-areas, and jobs during the survey. They collected: personal (breathing-zone) air samples for inhalable dust and inhalable soy antigen; personal (breathing-zone) and area air measurements for airborne dust of respirable and thoracic size fractions using a real-time sampler; and area air samples for inhalable dust, inhalable soy antigen, total dust, total endotoxin, selected metals, and particle size distributions. They also collected bulk samples of soy materials from different sub-areas of the plant. From July 23-August 2, 2007, NIOSH investigators also conducted a medical survey of current workers at the plant; it consisted of an interviewer-administered questionnaire; lung function testing, including spirometry, bronchodilator, and methacholine challenge testing; and skin and blood allergy testing. Inhalable dust exposures were highest for the autopack operator, unloading switch operator, and sanitation job categories. Some of the samples from these job categories, as well as from starch dumping, exceeded the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for total dust as particulate not otherwise regulated (PNOR) and the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLV) for inhalable dust. The task of starch dumping, which produced the highest dust concentrations measured (21.7 mg/m3), was typically done by workers from several different job categories outside their normal shift work, using respiratory protection. Detectable soy antigen air concentrations were measured in all plant areas and sub-areas; the highest geometric mean inhalable soy antigen area concentration was in the flake processing room (308,000 ng/m3). Job categories with the highest geometric mean soy antigen concentration as measured by personal samples included the unloading switch operator (27,540 ng/m3), curd operator (25,960 ng/m3), and unloading lead (14,360 ng/m3). Currently, there are no occupational exposure standards or guidelines specifically for soybean dusts, though the more general PNOR standard does apply to soybean dusts. The highest endotoxin concentration, 217 EU/m3, was measured in the flake processing room; all other endotoxin concentrations were below 50 EU/m3. Calcium was detected in 5 of 67 total dust air samples; if the calcium in these samples was all present as lime (CaO), the highest corresponding lime concentration in air would have been approximately 0.52 mg/m3, a level well below the existing OSHA standard for lime dust. Of the 281 workers currently employed at the plant by the Solae Company, 147(52%) consented to participate in the medical survey and completed the questionnaire. Participation rates varied by worker classification, ranging from 66 of 94 (70%) production workers to 42 of 114 (37%) non-production workers. NIOSH staff conducted lung function testing for 140 of these workers, skin allergy testing for 132, and blood allergy testing for 135. Participating workers at the Solae plant in Memphis had higher than expected prevalences of physician-diagnosed asthma, sinusitis, and wheeze (a symptom of asthma) compared to the U.S. adult population. The prevalences of current and ever physician-diagnosed asthma for participating males were higher than expected based on a survey of the state of Tennessee, but these differences did not reach statistical significance. Among participants with adult-onset, physician-diagnosed asthma, most were diagnosed after hire at Solae. The incidence rate was five times greater after hire than before hire, consistent with a temporal relationship of occupational exposures preceding asthma diagnosis. Compared to non-production workers, production workers were more likely to report asthma-like symptoms that improve away from work. Work-related asthma-like symptoms were also associated with peak dust concentrations. Compared to workers exposed to lower peak concentrations, participants exposed to higher peak concentrations of dust were more likely to report work-related asthma-like symptoms. Additionally, workers who reported seeing or smelling mold in the workplace were more likely to report work-related sinusitis, nasal allergies, and rash compared to workers not reporting this exposure. Fourteen participants (10%) had airways obstruction on spirometry (six borderline and eight mild or worse severity). Eleven (8%) had spirometry results indicating a restrictive pattern. One had both airways obstruction and restriction. Two had a clinically significant response to bronchodilator and 12, including eight without airways obstruction on spirometry, had evidence of bronchial hyperresponsiveness on methacholine challenge testing. The prevalence of positive immunoglobulin E (IgE) to soy among Solae workers was five times greater than the prevalence among a group of comparison workers who were not occupationally exposed to soy, suggesting that immune recognition of soy among Solae workers resulted from occupational exposures. All asthma outcomes were significantly associated with immune response to soy, as measured by soy-specific IgE levels in the blood but not as measured by the skin prick test for soybean allergy. Concentrations of soy antigen and dust exposure were process-related. Compared to workers exposed to lower peak concentrations, those exposed to higher peak dust concentrations (measured by real-time sampling) were more likely to have spirometry indicating airways obstruction and to report work-related asthma-like symptoms. In addition, level of immunoglobulin G (IgG) to soy was associated with inhalable soy antigen level and work classification. Time-weighted-average inhalable soy antigen and dust concentrations were not associated with asthma outcomes in analyses involving all participants. (Click to show less)
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(2008) Neurological dysfunction among workers exposed to trichloroethylene. (Click to open report)
On August 24, 2004, NIOSH received a technical assistance request from the Oregon Department of Human Services concerning dementia and neurologic dysfunction among workers exposed to TCE at Entek International in Lebanon, Oregon. In an initial NIOSH site visit in November 2004, NIOSH investigators found GA air concentrations of TCE ranging from 20 to 40 ppm in production areas. A medical questionnaire revealed that 48% of Entek International workers reported feeling high or lightheaded while at ... (Click to show more) On August 24, 2004, NIOSH received a technical assistance request from the Oregon Department of Human Services concerning dementia and neurologic dysfunction among workers exposed to TCE at Entek International in Lebanon, Oregon. In an initial NIOSH site visit in November 2004, NIOSH investigators found GA air concentrations of TCE ranging from 20 to 40 ppm in production areas. A medical questionnaire revealed that 48% of Entek International workers reported feeling high or lightheaded while at work in the last 30 days, compared to 19% of non-TCE exposed workers at an adjacent facility, Entek Manufacturing. In a follow-up site visit in June 2005, NIOSH investigators collected full-shift and shorter-term PBZ and GA air samples for TCE on study participants on all four production schedules over a one-week period. Noise exposures were also measured. The medical evaluation included a health questionnaire, five neurobehavioral tests (Grooved Pegboard, Postural Sway, Trail Making, Visual Contrast Sensitivity, and Symbol Color Recode), and biological monitoring for TCAA, a metabolite of TCE. Mean full-shift PBZ air concentrations for TCE were below the OSHA PEL of 100 ppm, but above the extended 12-hour work-shift adjusted NIOSH REL of 21 ppm for extruders, winders, rovers, team leads, and supervisors. Shorter-term (13 to 48 minutes) TCE exposures ranged from 30 to 445 ppm, with the highest concentrations occurring during line maintenance. Production employees wore elastomeric half-mask air-purifying respirators equipped with a combination organic vapor/HEPA filter cartridge during product changeover or line maintenance activities, but not typically during routine work activities. Noise levels exceeded the NIOSH REL in extrusion, winding, palletizing, maintenance, and utility/rover jobs (such as fork lift operators); radios in some work areas contributed to noise exposures. Most workers wore hearing protection (plugs or muffs). Of 129 study participants, 82 were exposed to TCE. The groups were similar in age, but differed in average tenure and in education levels. The exposed group had a higher prevalence of former and current smokers, and consumed more alcoholic drinks on average than the unexposed. The TCE-exposed group had deficits in the following neurobehavioral tests compared to the non-exposed workers: lower visual contrast sensitivity scores for both eyes at 6 cycles per degree and at 12 cycles per degree for the right eye, a larger postural sway area for the most challenging test condition, and slower completion time in the Grooved Pegboard Test. The median urinary TCAA level in the exposed group was 50 mg/g creatinine (range: 0-223) compared to 0 mg/g creatinine (range: 0-2.2) in the unexposed. A total of 22 TCE-exposed participants (26.8%) had urinary TCAA levels over the ACGIH BEI (100 mg/g creatinine). (Click to show less)
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(2007) Highlights of the NIOSH health hazard evaluation: Copperhill smelter worker study. (Click to open report)
The union that represented some workers at the smelter asked NIOSH to study worker health. The union and people in the nearby community wanted to know if health problems were related to working in or living near the smelter. Although this study only included smelter workers, NIOSH thought the results would help answer questions about health in the community. Many people in the community worked at the smelter. Also, smelter operators had data about exposures in the plant. These data would help re... (Click to show more) The union that represented some workers at the smelter asked NIOSH to study worker health. The union and people in the nearby community wanted to know if health problems were related to working in or living near the smelter. Although this study only included smelter workers, NIOSH thought the results would help answer questions about health in the community. Many people in the community worked at the smelter. Also, smelter operators had data about exposures in the plant. These data would help researchers better understand whether smelter-related exposures were linked to health problems. Because a study of the smelter workers had been done in the 1980s, this study was possible. The researchers set the following four goals for the study: 1. Compare death rates and causes of death in smelter workers with those in the general population. 2. Describe the work environment in the smelter by work area, job title, and levels of exposure to six agents. 3. Describe the smoking history of smelter workers and use this information to help understand the cause-of-death results. 4. Examine whether specific causes of death were related to exposures in the smelter work setting. The study included 2,422 men who worked in the smelter, mill, or sulfur plant for 3 or more years between January 1946 and April 1996. For the years 1949 through 2000, the researchers found out whether these workers were living or deceased. If the workers were deceased, the researchers obtained information about their cause of death. The researchers used information from national and state records to learn whether people in the study had died. The researchers then obtained information about the causes of those deaths. They also used information from records in the smelter about the age, race, and sex of people in the study. They compared the number of deaths of smelter workers to the number that would be expected in groups of people who did not work in the smelter. These included the general population of the United States and the population of the counties around the smelter. They made these comparisons for all causes of death combined, for groups of diseases (such as all cancer or all lung disease), and for specific diseases (such as lung cancer or cerebrovascular disease, also known as stroke). They used statistical tests to decide if the results were meaningful. When they saw meaningful differences, they looked to see if death rates were related to exposure. They got exposure information from smelter records and by interviewing workers about smelter operations. To look at exposure, they grouped people by how long they worked in the plant, what department they worked in, their job title, and the level of exposure. They estimated exposure levels for lead, arsenic, cadmium, cobalt, dust, and sulfur dioxide based on records of workplace air sampling done by smelter operators. All causes of death. Of the workers in the study, 961 (41%) were deceased. Researchers found a cause of death for 878 of these. The total number of deaths expected among smelter workers was based on national and local county rates. For all causes of death, all types of cancer, all types of heart disease, respiratory disease other than cancer, and many of the specific causes of death, the rates in the surrounding counties were similar to the national rates. Cancer deaths. Of the workers in the study, 228 died of cancer. This was 18% lower than expected based on national rates and 16% lower based on local county rates. When specific types of cancer were looked at separately, some differences between smelter workers and the general population were found. Most of these differences were based on numbers of deaths so small they were not thought to be important. Eleven workers died of cancer of the central nervous system, an excess of 39% compared to the general population. By statistical tests, this difference was not meaningful. Noncancer deaths. The results did not show that smelter workers had a meaningful increase in the risk of death from any other cause of death. Levels of exposure. The average exposure levels for lead and sulfur dioxide were close to the current workplace limits for these agents. For arsenic, cadmium, cobalt, and dust, the past average exposure levels were much lower than current limits. Causes of death and exposure. After examining all causes of death and all measures of exposure, the researchers looked at two findings more closely. These were the link between arsenic exposure and stroke and the link between cadmium exposure and bronchitis. Stroke and arsenic exposure. Seventy workers died of stroke. The risk of death from stroke was higher for people who worked longer and for people with more arsenic exposure. By statistical tests, this difference was not meaningful. For example, workers with the highest level of total exposure were 1.5 times more likely to die of stroke than unexposed workers, but the p value, a measure of significance, was 0.17; a p value of 0.05 or less is regarded as statistically significant. Bronchitis and cadmium exposure. Seven workers died of bronchitis. The risk of bronchitis death was higher for some exposed workers than for unexposed workers. This finding, however, was not the same for all exposure groups or measures. For example, workers with a moderate level of total cadmium exposure were 14.8 times more likely to die of bronchitis than unexposed workers. But, workers with the highest level of exposure were only 3.8 times more likely to die of bronchitis. The p value for these findings was 0.06, not statistically significant. As with most studies of this type, some factors make it hard for researchers to draw firm conclusions about the findings. First, because complete and accurate information about cigarette smoking was not available, the researchers could not investigate how cigarette smoking affected causes of death. But, it is unlikely that this limitation had an important effect on the conclusions. Second, this study was smaller than studies of other workplaces. The small size makes it less likely that the findings will be statistically significant, even if there is a real risk. Because of this, it is helpful to look at the how the findings of this study fit in with the findings of other studies of smelter workers or of other workers with similar exposures. Death rates for Copperhill smelter workers were lower than expected for all causes of death and from specific cancer and noncancer causes. This is not an unusual finding in studies of workers. So, researchers looked to see if workplace exposures were related to the risk of death from specific causes. One finding of interest was for arsenic and stroke. Another was for cadmium and bronchitis. The researchers concluded it is unlikely that arsenic exposure caused increased stroke risk or that cadmium exposure caused increased bronchitis disease risk in Copperhill workers. This conclusion is based on the detailed analyses of the findings from this study and on evidence from other studies about these exposures and diseases. It is also important to note that other studies of smelter workers have shown that arsenic exposure is related to respiratory cancer. Arsenic exposures in the Copperhill smelter were lower than in other smelters studied. The researchers in this study did not see an increase in respiratory cancer risk. (Click to show less)
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