R. Lewis, K. Ong, M. Maureen, B. Denis, A. Dixit, S. Condoor, Saint Louis University School of Public Health, St. Louis, MO.
Emerging technology in the vacuum cleaning industry created the opportunity to make comparisons among older and newer technologies for the removal of common household contaminates from carpet such as dust mite allergen and lead. Investigators tested the lead and dust mite allergen removal of four vacuum cleaners that had either passed or failed an industrial trade association’s “Green”-labeling program compared with a high-flow heated water extraction method and a traditional upright vacuum cleaner. Reproducible quantities of house dust containing dust mite allergen or lead were applied to 60 carpet specimens, followed by embedding, hexapod wearing, and vacuum cleaning with six methods of cleaning. No statistical differences were found among all six cleaners for removal of lead with a mean removal efficiency of 60%; however, the high-flow, hot water extraction method was significantly more efficient for removal of dust mite Dermatophagoides farinae Group 1 allergen or Der f1 allergen than all other methods with an allergen removal efficiency of 96% (p = 0.006).
H. Kim, H. Lim, The Catholic University of Korea, Seoul, Republic of Korea.
This study was designed to measure the current status of IAQ in the subway trains and to evaluate the effects of the number of passengers on the variation of CO2 and PM10 concentrations during rush hours and nonrush hours in both spring and summer seasons. A subway line among eight currently in service in Seoul was chosen for the study. The numbers of on-board passengers were visually estimated and used to calculate the congestion rate by dividing the number by 160, which is the capacity to be accommodated in a compartment of a subway train. An IAQ sampling pack was placed on the middle of the shelf that is located in the middle of the train. CO2, temperature, and relative humidity were measured using a direct-reading NDIR instrument (aq-5000, SKC) and PM10 was measured using a direct-reading, light-scattering device (DUSTMATE, UK). ANOVA analyses were performed to compare selected pollutant concentrations within day and between seasons. Simple regression analysis was used to evaluate the relationship between the contaminant concentrations and the congestion rates. The congestion rates were higher during rush hours (76.3%) than during non rush hours (29.1%) (p<0.0001), particularly more in the morning hours (92.0%) than in the evening hours (76.3%) (p<0.0001). Concentrations of CO2 and PM10 ranged fron 692 to 5,970 ppm and from 63.2 to 321.0 µg/m3, respectively, during spring, while they were 800–4,5370 ppm and 45.1–347.9 µg/m3, respectively, for summer. Concentrations were generally higher during spring than in summer for both pollutants. The results of regression analysis showed that CO2 was very highly correlated with congestion rates (r2 = 0.6577, 0.7082) while PM10 showed no relationship (r2 = 0.0016, 0.0012). The results of this study showed that concentrations of CO2 frequently exceeded the IAQ guideline of 1,000 ppm. CO2, generated mainly by respiration of passengers, is believed to accumulate within the space because of an inadequate supply of outside air from the HVAC system of the subway train.
H. Lim, H. Kim, The Catholic University of Korea, Seoul, Republic of Korea.
A review of past research indicates that variations of air contaminants in the passenger compartments of subway trains have not been fully assessed. To evaluate indoor air quality in 10 subway lines in Seoul, concentrations of CO2, PM10, formaldehyde, bacteria, and total volatile organic compounds were measured during the spring season. The following instruments were used: CO2, temperature, and relative humidity with a direct-reading NDIR instrument (aq-5000, SKC); PM10 with a direct-reading, light-scattering device (DUSTMATE, UK), formaldehyde with a portable electrochemical sensor instrument (TM-400, PPM Technology, UK), bioaerosols with the impactor method on TSA media (28°C, 48 hours), and total volatile organic compound with sampling sorbent tubes (Tenax TA) followed by GC/MS (HP 6890) and thermal desorption analyses. This study found the following results: CO2 ranged from 409 to 6,520 ppm, while PM10 ranged from 46.5 to 363.8 µg/m3. Concentrations of formaldehyde were 0.005 to 0.34 ppm, TVOC were 59.3 to 600.5 µg/m3, and total bacteria were 42 to 216 cfu/m3, respectively. Since concentrations of some pollutants found in the subway trains exceeded current IAQ guidelines (WHO, Hong Kong), sources of these contaminants as well as effectiveness of control measures such as HVAC systems should be evaluated.
D. Contreras, USACHPPM-North, Fort George G. Meade, MD.
U.S. Army Center for Public Health and Preventive Medicine-North personnel investigated and followed up Indoor Environmental Quality (IEQ) concerns at two North American Air Defense Command (NORAD) facilities. The first facility, constructed in 1956, operated until 1965 when the Air Force Semi-Automated Ground Environment (SAGE) Complex system was phased out. This building is an aboveground, hardened, concrete structure consisting of a 150 foot x 150 foot block, four-story section, designed without windows. The second building, a former Nike Missile Master base, was converted to an administrative building in 1975. The unique designs of these converted defense facilities have presented thermal, comfort, and ventilation issues. The windowless design fueled employee perception of discomfort and desire for ambient light. Other issues were created by employees providing “fixes” to the office spaces before renovation completion. The long corridors and building height often created tunneling effects through the building. Recommendations implemented by management were establishing a preventive maintenance program, reviewing and annotating modifications to as-built drawings, keeping all entrance/egress and fire doors closed, and providing training to HVAC personnel. Completed IEQ questionnaires compiled before the surveys and interviews based on occupant responses led to identifying and remediating many IEQ problems. Occupants felt involved in the process as the entire air distribution system was examined, interviews were conducted, and IEQ instruments were employed in offices. Findings were discussed with occupants and data was provided for each of the occupied spaces.
P. Hopper, Earth Tech, Brooks City-Base, TX.
Aircraft museums throughout the United States may be potential sources of radioactive contamination. Radioactive dials, gauges, signs, and other assorted aircraft components containing depleted uranium, krypton-85, cesium-137, thorium-232, nickel-63, radium-226, and tritium can be found in the majority of aircraft made before 1950. These contaminants must be removed to eliminate or significantly reduce radioactive exposures to museum personnel and the general public. The two-week remediation effort required locating, removing, labeling, and disposing of hundreds of radioactive items in 37 museum fighter, bomber, transport, attack, and rotary aircraft. Several factors hindered the remediation process. With little data available on older aircraft, locating radioactive components is extremely difficult without aircraft maintenance experience. Radioactive engine exciter boxes, pressure regulators, circuit breakers, flight control counterweights, leveling bubble indicators, and cockpit gauges are often situated in obscure and hard to reach locations. Wearing Tyvek suits, full-face respirators, gloves, boots, and a hard hat during the remediation made working in cramped spaces extremely difficult. Thermal stress was a constant problem as external temperatures varied from 35° F to 90° F. Workers were forced to maintain ergonomically awkward positions when removing components from high, small, and inaccessible aircraft locations. Several inches of rain formed “ponds” around many of the aircraft making working conditions extremely hazardous. The radioactive components were photographed, bagged, labeled, and placed in 55-gallon drums for disposal. A final radiological status survey was conducted to quantify the radiation levels in and around each aircraft. This complex project encompassed many facets of industrial hygiene. The project manager, a certified industrial hygienist, had to solve problems with personal protective equipment, ergonomic and thermal stress, physical barriers, waste disposal, radiation exposures, and inclement weather. It was a true test of industrial hygiene skills.
L. Whitehead, University of Texas School of Public Health, Houston, TX; V. Rodriguez, Lubrizol Corporation, Houston, TX.
This study identifies utilization and need for IHs, by industry division, industry, and overall. Two-digit Standard Industrial Classification (SIC) codes were assigned to each organization that employs CIHs/IHITs, in rosters of the ABIH. Totals were compiled for the years 1997, 1999, 2001, and 2003. Prior tabulations for years spanning 1990 to 1996 were also utilized. Statistics are presented showing trends in numbers of IHs and the number of workers per IH (an indicator of utilization of IH services) by industry, industrial division, and overall from 1990 to 2003; average annual percentage changes are presented. Projections to 2010 were made using two methods. Projections were made based on BLS estimates of employment by industry in 2010, assuming a constant number of workers per IH. Projections were also made based on numbers of IHs for past years. Overall, the total number of IHs has not increased since 1999. Industry divisions with the most IHs in 2003 are services (SIC 70–89, including consulting) and manufacturing (SIC 20–39), at 2,209 and 1,558, respectively. Among industry divisions with at least 50 IHs in 2003, construction (SIC 15–17) and services (SIC 70–89) have the highest average annual growth rates from 1990–2003, 29.4% and 7.2%, respectively, although consulting, the main element in services, has leveled off recently. Manufacturing grew at 1.5% per year from 1990–2003. Workers per IH generally show improvement, but in some industries this is based on reduction in workers rather than increase in IHs. Petroleum (SIC 29) and chemicals (SIC 28) have the most favorable (lowest) number of workers per IH, at approximately 700 and 1,600, respectively, in 2003. Projections of need for IHs by 2010 vary according to model used, and ranges will be presented; the services division, including consulting, health care, and education, will require the most additional IHs of any division.
T. Schoonover, UIC School of Public Health, Chicago, IL.
Researchers and handlers of laboratory animals are exposed to particulate matter, gases, endotoxins, and allergens. Between 11–44% of researchers and handlers exposed to animal allergens report symptoms and 4–22% of those develop occupational asthma. Cumulative exposure to mouse allergen has been shown to be related to immune-mediated sensitization in a dose-dependent manner. Endotoxins have been associated with respiratory symptoms in nonsensitized researchers and handlers. This study was designed and conducted to assess the effectiveness of mouse cage microisolator covers in controlling emissions and exposures in a laboratory animal research facility. Area sampling was conducted simultaneously in two mouse rooms, an adjacent hall, an office, and a cage-washing room. Sampling was done five days prior to and following cage cover installation. Area samples were collected on individual agent-specific open-face filters. Allergens were analyzed using mouse urinary allergen (Mus m 1) ELISA. Endotoxins were analyzed with a Lymulus Amebocyte Lysate test. Particulate matter samples were analyzed gravimetrically with a Sartorius microbalance. All agents of interest decreased significantly in concentration in the mouse rooms after installation of microisolator covers. Mouse allergen decreased from median concentrations of 10 to 0.02 ng/m3 (p = 0.010). Particulate matter decreased from median concentrations of 0.02 to 0.01 mg/m3. Endotoxins decreased from median concentrations of 6.6 to 0.4 EU/m3. The microisolator cage covers appear to be effective in decreasing concentrations of emissions and subsequent exposures to particulates, allergen, and endotoxins in laboratory environments.
C. Lai, T. Wu, Chung Shan Medical University, Taichung, Taiwan Republic of China; F. Tang, Changhua Christian Hospital, Changhua, Taiwan Republic of China; Y. Yan, National United University, Miao-Li, Taiwan Republic of China; S. Tsai, National Taiwan University, Taipei, Taiwan Republic of China; D. Tang, Institute of Occupational Safety and Health, Taipei, Taiwan Republic of China.
In Taiwan, deaths of vegetable-pickling workers were probably due to the inhalation of toxic gas in the working environment. The air sampling from the pickle tank revealed higher concentration of ammonia, carbon dioxide, and sulfide than ambient air. These reports showed the vegetable-pickling processes, including vegetable soaking and storing in brine and stirring the brine, probably released volatile and toxicant gas or caused blackdamp in the work. Little is known about the effects of the work environment on health in vegetable-pickling workers, though there were several publications about respiratory symptoms or allergic reactions caused by vinegar or acetic acid ingestion. The research included the laboratory simulation and field study. A plastic, square tank was used in the laboratory simulation of radish pickle. A 1.5*1*3 cubic meter tank was used to simulate radish pickling. A real time instrument Mini InfraRed Analyzer (MIRAN) was used to monitor the releases of volatile gases in the pickling process. Teflon sampling bags canisters were used to collect volatile gas presenting in pickle fermentation. A GC/MS was used to analyze volatile gas subsequently. The traditional process of pickle fermentation was used for this study. In field study, vegetable-pickling factories were recruited for the field sampling. The sampling strategies used in the field study were similar to the strategies performed in the laboratory simulation. MIRAN and GC/MS were used to monitor and analyze volatile gases from the pickle tanks. The evaluating results of monitoring the gas composition present in the working sites were compared with the data from the laboratory simulation. The goals of the study were trying to clarify the probable existing hazardous gas present in the pickling process and formulate suitable guidelines for reducing potential accidents.
J. Jang, S. Jung, OSHRI for Kosha, Incheon, Republic of Korea.
Five pesticide formulation factories were investigated to identify workers exposure to the pesticide named mancozeb. Mancozeb is a complex of zinc and maneb containing 20% manganese and 2.55% zinc; the chemical name is ethylene bis(dithiocarbamic acid) manganese zinc complex. The wettable powder pesticide sampled on cellulose ester membrane filters through personal air sampling with 2 LPM sampling rate, was gravimetrically weighted for calculation of dust concentrations and analyzed for manganese and zinc by ICP. Forty-two workers participated in this study for the two consecutive days monitoring program. The data on mancozeb dust and metals in the pesticide distributed log-normally, rather than normally. Geometric means (geometric standard deviations) for dust, manganese, and zinc were 0.566 mg/m3 (2.16), 5.36 mg/m3 (4.94), and 1.06 mg/m3 (3.71), respectively. ACGIH TLVs for 2005 are 0.2 mg/m3 and 5 mg/m3 for manganese and zinc oxide. AIHA WEEL for mancozeb is 1.0 mg/m3 in 2005, while ACGIH has not published a TLV. Day-to-day variations using paired t-test showed no statistically significant differences, with p > 0.05 for dust, manganese, and zinc. Dust concentrations were highly correlated to manganese and zinc concentrations (R2 = 0.552 and 0.447, respectively), indicating that metals were well-suited as identification methods for airborne mancozeb at pesticide formulation sites. Least solvents could dissolve the pesticide, which makes it difficult to be analyzed by GC or HPLC. Currently, there are no methods for mancozeb analysis in NIOSH or OSHA methods.
M. Methner, C. Achutan, NIOSH, Cincinnati, OH.
NIOSH received a health hazard evaluation request from a fire/rescue vehicle ladder manufacturer to evaluate employee exposures to hexamethylene diisocyanate (HDI) VOCs, particulates, and silica during sanding and painting activities. PBZ samples for HDI and VOCs were collected on 15 workers engaged in painting. Eleven workers were monitored for particulates while sanding ladders. Airflow rates within two side-draft spray booths were measured and compared with recommended guidelines. No air samples collected for HDI monomer exceeded the NIOSH REL of 35 micrograms per cubic meter (µg/m3). No OSHA PEL for HDI monomer exists. However, the United Kingdom Health and Safety Executive (UK-HSE) publishes a Total Reactive Isocyanate Group (TRIG) eight-hour time-weighted average (TWA) limit of 20 µg/m3 and a Ceiling Limit of 70 µg/m3. Of the 15 painters sampled for HDI, six had PBZ levels that exceeded the TRIG eight-hour TWA, while four workers exceeded the TRIG Ceiling Limit. VOC samples were below occupational exposure criteria. All painters wore PPE; however, the choice of latex gloves offered little skin protection from isocyanates. Additionally, workers often got paint on their skin during mixing and used methyl ethyl ketone to remove it. Airflow measurements in one paint booth revealed inadequate ventilation (<100 fpm) while the other booth was approximately seven times higher. Two workers who sanded ladders had particulate exposures that exceeded the ACGIH TLV (10 milligrams per cubic meter of air [mg/m3]), while another worker exceeded the OSHA PEL of 15 mg/m3. No silica (quartz and cristobalite) was found in the air samples. Workers who sanded sometimes used N95 filtering facepiece respirators. Recommendations included: use of NIOSH-approved N95 filtering respirators during sanding; the development of a formal respiratory protection program; maintaining at least 100 fpm airflow in all spray booths; and use of nitrile gloves when mixing/spraying paint.
J. Boiano, G. Piacitelli, K. Sieber, NIOSH, Cincinnati, OH; J. Catalano, N. Heyer, B. Payne, Battelle Centers for Public Health Research and Evaluation, Seattle, WA.
The National Exposures at Work Survey (NEWS) is intended to collect descriptive data from employees regarding health and safety practices and perceptions, potential exposures, and interventions in workplaces across the United States. The feasibility of collecting this type of information using a self-administered employee questionnaire in the health services sector was evaluated by pilot-testing paper and web-based modes and selected distribution protocols in a large medical center. The employee questionnaire consisted of a core module (for completion by all employees) addressing broad-based health care issues (e.g., overtime, violence, stress) and 10 targeted hazard modules addressing selected chemical agents (e.g., antineoplastics, sterilants, anesthetics). Approximately 1,000 employees were divided into two distribution groups: (1) employees (n = 501) who received a personalized letter with a paper core module, and (2) employees (n = 499) who received a personalized letter only. The letters provided a toll-free number for assistance on how to request additional paper modules if needed (Group 1), and how to request a customized paper questionnaire (Group 2), based on responses to screening questions. Both groups were also provided instructions on how to access the Web-based survey. Overall, 35% of sampled employees completed the survey, including 42% (n = 210) in Group 1 and 29% (n = 146) in Group 2, with the Web survey being slightly preferred (51%). Seventy-nine percent of Group 1 respondents preferred the paper mode, whereas 95% of Group 2 respondents preferred the Web. Accurate completion of the paper questionnaire was a problem for 82% (n = 44) of the respondents who failed to request additional modules even though their responses to screening questions indicated that they needed to complete (and therefore request) one or more hazard modules. This problem was not observed in the Web survey; it was seamless with respect to the modules. Methods of improving the paper survey and overall response rates will be presented.
E. Goswami, R. Kalmes, Exponent, Oakland, CA.
Several investigations of occupational exposures to volatile compounds among nail salon workers have been published. However, few studies have investigated personal exposures outside of nail salons to consumers using nail care products. Exposures to carcinogens such as formaldehyde, which is found in fingernail hardening products, is of particular concern in California where product warnings are required if exposures are greater than specified no-significant-risk levels. An exposure study was conducted in which four participants were monitored during three 20-minute product use simulations. Participants were asked to apply two coats of a nail-hardening product containing formaldehyde to their nails and allow them to dry during each 20-minute session. Prior to each session, sampling rooms were adequately ventilated by use of a negative air machine, and background samples were collected prior to initiating each exposure simulation. Breathing-zone samples during product use simulations and background room samples were collected by passing air through DNPH silica gel tubes by means of a personal pump at a flow rate of approximately 0.7 liters per minute for 20 minutes, for a sampling volume of approximately 14 liters each. The silica gel tubes were analyzed by NIOSH method 2016 (HPLC/UV). The 12 concentrations measured during the simulation ranged from 2.8 to 12.1 µg/m3, with a mean of 6.8 µg/m3. According to the U.S. EPA, formaldehyde is normally present at low levels, usually less than 0.03 ppm (37 µg/m3), in both outdoor and indoor air. These levels are within this range. In addition, daily dose calculations for regular use of nail-hardening products indicate that potential formaldehyde exposures are less than California’s no-significant-risk level.
R. McCleery, R. Tubbs, A. Warren, CDC/NIOSH, Cincinnati, OH.
A health hazard evaluation request was submitted to NIOSH from employees of a cultured marble manufacturing facility who were concerned that their headaches, itchy skin, and respiratory issues were related to exposures from chemicals and dust generated in the production of cultured marble bathroom vanities, tubs, walls, and floors. NIOSH investigators responded with two site visits in 2004–2005 to gather pertinent facility information and conduct a comprehensive evaluation of employee exposures, including personal exposure sampling for total and respirable particulate, styrene, á-methyl styrene, methyl methacrylate, and noise during various facility operations. Respirable particulate, á-methyl styrene, and methyl methacrylate air sample concentrations were all below OSHA, NIOSH, and ACGIH evaluation criteria. Total particulate concentrations were all below relevant evaluation criteria except for that of the product grinder whose eight-hr TWAs were 38 mg/m3 and 43 mg/m3 over two days of sampling. Styrene concentrations were below relevant evaluation criteria except for those of two mold pourers whose eight-hr TWAs of 22 and 31 ppm exceeded the ACGIH limit of 20 ppm. Noise monitoring data indicated that the individual daily noise doses of the product grinder and a product buffer exceeded the allowable amount according to the OSHA PEL noise criterion (246% and 140%, respectively). Using the NIOSH noise criterion, virtually all employees whose noise dose was evaluated exceeded the daily allowable noise dose (ranging from 92% to 2,339%). Based on the air sampling and noise monitoring results, NIOSH investigators provided the company with recommendations to improve the safety and health of employees that included, but were not limited to, establishing written respirator and hearing conservation programs, changes to compressed air nozzles and mold vibration tables to reduce generated noise, and training employees on the appropriate use, storage, etc., of personal protective equipment.
Posted May 30, 2006