Poster Session 4


Tuesday, May 24, 2016, 1:00 PM - 3:00 PM

*All posters are available for viewing in the expo hall from Monday 9:00 a.m. through Wednesday 1:00 p.m.


Time Trends in Formaldehyde Emissions from Laminate Flooring Products After Installation

P. Ruestow, J. Lotter, A. Abelmann, H. Fritz, E. Beckett, and J. Pierce, Cardno, Chicago, IL; K. Unice and J. Bare, Cardno, Pittsburgh, PA

Objective: To address recent concerns surrounding formaldehyde emissions from Chinese-made laminated flooring products, we evaluated time trends in airborne formaldehyde concentration following the installation of two flooring products in a real-world office setting.

Methods: Two types of laminate flooring products from a single retailer were installed in two separate rooms with similar ventilation in an office building. After installation, a total of 24 passive 24-hour samples were collected from each room over the course of 35 days using diffusive badge samplers. Expected time to steady-state in each room was estimated using results from experimental small chamber testing, room volume, and room airflow rates, assuming a constant emission rate and no adsorptive sinks. Room concentrations would be expected to remain constant after reaching steady-state. A repeated measures, mixed effects analysis was conducted. Repeated samples were defined according to sampler location in the room, and these sampler locations were assumed to be clustered by room. Mixed modeling techniques were used to investigate trends over time during the post-installation period and during the expected steady-state time period.

Results: The overall average 24-hour formaldehyde concentrations following the installation of the laminate flooring were 0.038 ppm (range: 0.020 - 0.058 ppm) in Room 1 and 0.022 ppm (range: 0.013 - 0.039 ppm) in Room 2, both statistically higher than their respective background concentrations. The average formaldehyde concentrations in both rooms increased with time after installation and did not appear to plateau during the post-installation study period, after accounting for correlations and clustering among samples. The amount of time required for 24-hour average concentrations to reach steady-state under ideal conditions was estimated to be 2 days or less. Time was significantly associated with concentration during the entire post-installation period (p < 0.001) and during the expected steady-state period (p < 0.001).

Conclusions: This time trend analysis indicated that steady-state was not reached during the study period, possibly due to room sinks (e.g., wall board, ceiling tiles) or changes in the source emission rate. Further study is necessary to understand why emission trends might differ between experimental and real-world settings. 


Evaluation of Diurnal Variations in Formaldehyde Concentrations Following Installation of Laminate Flooring Using Real-Time Sampling

H. Fritz, J. Lotter, A. Abelmann, P. Ruestow, E. Beckett, and J. Pierce, Cardno ChemRisk, Chicago, IL; K. Unice and J. Bare, Cardno ChemRisk, Pittsburgh, PA

Objective: It is well known that certain building materials may release formaldehyde for some time following installation, but limited data exist regarding the variation in air concentrations as a function of room characteristics, such as ventilation rates. Therefore, a study was conducted to evaluate the concentration of formaldehyde following the installation of laminate flooring under varying ventilation conditions.

Methods: Laminate flooring was installed in a 27.62 m3 room that was equipped with an air exhaust outlet, but no air supply inlet and contained painted drywall wall, drop ceiling tiles, and no furniture. Following installation, real-time airborne measurements of formaldehyde were collected during weekdays for five weeks using a portable direct read formaldehyde analyzer and were logged every 5 min. The ventilation rate in the study room was evaluated during daytime, when the ventilation system was in operation, and nighttime, when the system was not in operation. The overall diurnal trend in formaldehyde concentrations was evaluated and the concentrations measured during periods in which the ventilation system was in operation were compared to periods without ventilation.

Results: The air exchange rates were 5.1 hr-1 and 0.52 hr-1 when the ventilation system was and was not in operation, respectively. The higher daytime ventilation rate was consistent with rates reported for well-ventilated office buildings, whereas the lower rate was likely representative of a residential dwelling without mechanical ventilation. As expected, formaldehyde levels increased in the nighttime (average: 0.019 ppm; range: 0.008 - 0.056 ppm) and decreased during the daytime (average: 0.012 ppm; range: 0.007 - 0.023 ppm). The average nighttime concentration was about 1.6-fold higher than the previous daytime concentrations, despite the nearly 10-fold lower nighttime ventilation rate.

Conclusions: Within a given 24-hr sampling period, formaldehyde concentrations increased as ventilation rate decreased, though the relative increase was less than expected based on the difference in ventilation rate. These results indicate that factors other than ventilation affect the room concentrations. Further, these results suggest that persons living or working in a room without mechanical ventilation may experience higher concentrations of formaldehyde following the installation of laminate flooring.



Studies of the Nicotine Personal Sampler Using PUF Media and That Simple Analysis

Y. Suzuki and T. Enomoto, SIBATA Science Technology Ltd., Saitama, Japan; Y. Yanagisawa, Tokyo Univ., Tokyo, Japan; M. Noguchi, Sekei Univ., Muasino, Japan

Objective: We improve a sampler system for the atmospheric Nicotine measurement that we reported in AIHA2015, and the low-concentrated measurement is enabled last time. Furthermore, we examine analysis technique and can measure nicotine in the general-purpose analytical instrument sensitively. It was in this way intended to enable the measurement to evaluate the atmospheric nicotine concentration that WHO suggested.

Methods: We used the Semi-Active sampler which we reported in AIHA2014 in this study. On the occasion of nicotine sampling, reexamined technique to adsorb to PUF (Poly-Urethane Form). The alkaloids-based chemical substances such as nicotine show stabilization in an acid condition. Therefore, we decided to perform acid treatment of PUF. Assumed this acid impregnation PUF an adsorbent and carried out the recovery measurement when we used the sampler. In addition, for the samples obtained for this sampler, we went a storage test of up to one week. About the examination of the analysis technique, we improved sensitivity by making the separation with the gas chromatograph better.

Results: Collecting efficiency showed approximately 600ml/min in this revised method. As a result, became able to evaluate nicotine concentration of 0.1-1 μg/m3 that was the concentration that WHO guidelines required in sampling for 24 hours by this technique. we were able to confirm that we held nicotine which sampled by refrigerating a sample after the atmosphere sampling, and keeping it by 90% on PUF.

Conclusions: This technique was able to enable the measurement of atmospheric nicotine in the low concentration by using acid impregnation PUF adsorbent. In addition, it is thought that PUF absorbs particle-formed nicotine unless it is gaseous. We suppose that this technique can fit the measurement in the air such as semi volatile organic compounds (SVOCs) from this thing.



Evaluation of the Stretch-Effect by the Psychosocial Stress of Workers in Small Workplaces

S. Lee, S. Lim, S. Lee, and S. Cho, Gyeonggi Dongbu Workers' Health Center, Seongnam-si, Korea (the Republic of); J. Koo, The Catholic University in Korea, Seoul, Korea (the Republic of)

Situation/Problem: This study aimed to understand the relationship between psychosocial stress levels and alterations of musculoskeletal pain perception levels after stretching treatment program in 210 workers of small workplaces with less than 50 workers.

Resolution: Subjects were evaluated with visual analog scale(VAS), psychosocial well-being index short form(PWI-SF), and cardiovascular disease risk factors before and after a 4 week long stretching treatment programs customized for pain regions of each subject.

Results: 1. Psychosocial stress levels were evaluated in 73 subjects among 210 workers participated in this study. Twenty subjects (27.4%) were in a high-risk group of psychosocial stress with high PWI-SF values being greater than 27 while the other 53 subjects (72.6%) showed normal stress levels. 2. Subject were classified into subgroups according to body parts with musculoskeletal pain. and the shoulder was abundant pain region in 20 subjects (27.4%) followed by the lower back in 47 subjects (22.4%) and the neck in 37 subjects (17.6%). After the stretching treatment program for 4weeks, levels of musculoskeletal pain perception were significantly reduced while the VAS decreased from 4.34(±2.34) to 2.36(±1.94) after the program(p<0.0001). 3. The VAS results prior to the stretching treatment program have been analyzed in 210 subjects and have shown a significant difference of VAS values between office and production workers(p<0.041). 4. Statistics showed that there was no significant correlation between psychosocial stress measured with PWI-SF and musculoskeletal pain perception measured with VAS in 73 participated subjects. 5. Levels of musculoskeletal pain perception were compared in 31 subjects of both normal and high-risk psychosocial stress groups before and after the stretching treatment program of 4 weeks. Musculoskeletal pain perception measured with VAS were significantly reduced after the stretching program in the normal psychosocial stress group(p<0.006) whereas the high-risk group showed no significant changes of VAS(p<0.153).

Lessons learned: Taken all together, these data demonstrate that the 4-week long stretching treatment program was overall beneficial for subjects with musculoskeletal pain. In association with the level of psychosocial stress level, however, the stretching treatment program was effective in the normal stress group but not in the high-risk stress group. Therefore, additional interventions would be required to alleviate musculoskeletal pain in small workplaces workers with a high-risk psychosocial stress level.



Pilot Study: Antineoplastic Drug Contamination of Surfaces at a Long-Term Care Facility

C. Hon, Ryerson University, Toronto, ON, Canada; E. Jelley, University of Toronto, Toronto, ON, Canada; P. Demers, Occupational Cancer Research Centre, Toronto, ON, Canada

Objective: Occupational exposure to antineoplastic drugs is associated with genetic damage, reproductive toxicities and an increased risk of cancer. Healthcare workers’ exposure to these agents is believed to be mainly through dermal contact. As such, a work surface or object with antineoplastic drug contamination is a potential source of exposure. To date, antineoplastic drug contamination of surfaces has been detected in every publication performed within acute care facilities. However, these agents are also handled and administered in long-term care facilities and this study sought to ascertain drug surface contamination levels within such a facility in Toronto, Canada.

Methods: Site observations were performed to identify those surfaces most frequently contacted by nurses who handle antineoplastic drugs. These surfaces, distributed over two floors of the facility, were then wiped and the amount of methotrexate, a common antineoplastic drug used in this facility, was quantified using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS-MS) technology. The limit of detection was 0.05 ng/mL (0.001 ng/cm2).

Results: Twenty-two work surfaces/objects were sampled within the facility and none had detectable levels of methotrexate (i.e. all samples less than 0.001 ng/cm2).

Conclusions: From an occupational health and safety perspective, the results are reassuring. However, they should be treated with caution as this was a pilot study and several factors may have influenced the findings including, but not limited to, lower patient dose, infrequent drug administration, and medication in tablet form. All three of these parameters differ from acute care settings.



Characterization of Emissions from 3-Dimensional Printing Operations: A Literature Review and Sampling Framework for Future Evaluations

R. Zisook and B. Simmons, Cardno ChemRisk, San Francisco, CA

Objective: The use of three dimensional (3D) printers in commercial and industrial settings is increasing. However, few studies have been conducted to characterize potential human and environmental health hazards associated with their use. The objectives of this research are to provide a synthesis of the existing information, identify data gaps, and to provide a framework for evaluating potential hazards that have not been well characterized.

Methods: A review of the literature on 3D printing emissions and breakdown products of common feedstock materials was conducted. For 3D printer types and feedstock materials that have not been characterized in the literature, a review of safety data sheets (SDS) was performed.

Results: Although limited, emissions data are available for fused deposition modeling (FDM), multi-jet modeling (MJM), and stereolithography (SLA) 3D printer types. Feedstock materials evaluated include thermoplastics (acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA)) and acrylic photopolymers/resins. Existing studies have measured: particle number, mass, and size distribution; VOCs (including styrene, a known asthmagen); and ozone (not detected). Differences in emissions were observed between feedstock and printer types. For example, styrene concentrations ranged from <LOD (PLA) to 66 ppb (ABS), and total VOC concentrations ranged from <1 ppm (FDM, MJM, SLA) to 15.1 ppm (MJM). When applicable, data were converted to potential worker exposure levels and compared to OELs. These levels were found to be below OELs; however, significant data gaps exist (e.g., individual VOCs were not measured for MJM). FDM printers were characterized as being high emitters of ultrafine particles (particle emissions were reported to be above background levels). However, particle characterization analyses have not been performed. In one study, cleaning of polymeric products was found to result in the highest potential for worker exposure. Some SDS sheets report skin sensitization hazards.

Conclusions: Emissions during 3D printing operations vary depending on feedstock composition, printer type, and other factors. The available data are limited and are not directly comparable. Future studies should evaluate: individual VOC concentrations, particle count/characterization, task based sampling of post-processing activities (e.g., cleaning), and the effectiveness of control measures. Additional printer types and feedstock materials (e.g., nylon/metal powder) should also be evaluated.



Female Maximum Acceptable Peak Force for Pulp Pinch Insertion Task in Taiwan

A. Chen and E. Lo, Department of Occupational Safety and Health, China Medical University, Taichung City, Taiwan

Objective: The Occupational Safety and Health Act, enacted on July 3rd, 2014, has been issued by the Ministry of Labor, Republic of China (Taiwan) . A guideline with several checklists to assess the risk of developing the work-related musculoskeletal disorders has also been proposed for a later date. However, these checklists mainly were designed and used to assess the risk in the Western countries, which may or may not be suitable in Taiwan. This methodology has been used in the development of guidelines for manual materials handling, and similar methods were applied to repetitive upper limb movements recently. The purpose of this study is to investigate the maximum acceptable force with middle and high duty cycles for pulp pinch task for females in Taiwan.

Methods: Eighteen females will be recruited to perform a simulated pulp pinch insertion task. There are 6 subjects in one of three age groups (20-30, 31-45, 45+). The independent variables are insertion frequency (15 and 20/min), duty cycle (50%, 65%, and 80%) and hour of day (hours 1-7). Each subject will be trained for 11 hours with each combined condition. Subjects are asked to exert force as hard as they can at the test frequency and duty cycle combinations for full 8-hour workday without developing any discomfort, injury or fatigue in the upper limb. For each trial, the dependent variables are maximum acceptable peak force and symptom rate. The wrist is in neutral position when performing the pulp pinch task.

Results: We expect to find out that the maximum acceptable peak force for females in Taiwan should be significantly less than the force reported from studies in U.S. The maximum acceptable peak force is decreased when the age, frequency and duty cycle are increased. The symptoms of soreness, stiffness and numbness are increased as the day progressed.

Conclusions: Based on aforementioned results, this study will contribute to our understanding of difference of the maximum acceptable force for pulp pinch insertion task between Taiwanese and working population in western countries. Furthermore, the results of this study can be used to see if it is necessary to make modification when applying these checklists to assess the risks of development of work-related musculoskeletal disorders.



Risk-Based Evaluation of the OSHA Oil and Gas Benzene PEL

A. Duane, Chemistry & Industrial Hygiene, Inc., Wheat Ridge, CO

Objective: Recent NIOSH studies have shed light on high levels of employee exposures to benzene experienced during tank gauging activities in flowback operations at oil and gas production sites. Utilizing these studies and other recent benzene exposure information, we wanted to estimate the number of current oil and gas industry employees expected to contract a benzene related illness. Additionally, we wished to determine the excess risk to employees exposed at the oil and gas industry benzene PEL of 10 ppm in comparison to other commonly used exposure limits.

Methods: Using the recent exposure assessments, the excess risk for developing leukemia for the exposed population was calculated following the risk assessment strategies published by the National Research Council. Unit risk data was taken from the EPA’s report on the carcinogenic effects of benzene. Excess risk calculations were also performed using the oil and gas industry PEL, the general industry PEL, and the NIOSH REL to demonstrate the effectiveness of protection at each limit.

Results: Risk for developing leukemia for an employee working 40 hours per week for 10 years exposed at 10 ppm (oil and gas PEL) is 1 in 110; at 1 ppm (general industry PEL) the risk is 1 in 1,100; and at 0.1 (NIOSH REL) the risk is 1 in 11,000. Based on U.S. Bureau of Labor Statistics information, exposure at 10 ppm for production level employees could lead to almost 1,000 excess cases of leukemia.

Conclusions: The current oil and gas industry benzene PEL is not sufficiently low to adequately protect workers. The findings demonstrate that compliance with the regulations does not necessarily ensure protection from illness. In many cases, a risk-based approach to evaluating exposures is more effective in communicating a need for additional controls or protective equipment than a direct comparison to exposure limits.



An Analysis of OSHA Violations: Occupational Exposures to Benzene

P. Williams, E Risk Sciences, LLP, Boulder, CO

Objective: The purpose of this investigation was to characterize the number and type of OSHA Benzene Standard violations and corresponding violations of OSHA’s Hazard Communication Standard (HCS). These data, which have not been previously reported or analyzed, may be of interest to industrial hygiene professionals involved in benzene risk assessment, risk management, or public policy issues.

Methods: OSHA violation and inspection data collected since the 1970s were obtained from the Department of Labor enforcement website. A total of 938 violations of the benzene standard were identified and analyzed. Over 550,000 HCS violations were also evaluated.

Results: The number of benzene standard violations were found to vary by time period, standard provision, industry sector, and other factors. Approximately 70% of violations occurred during the late 1980s to early/mid-1990s, soon after the 1987 final benzene rule was promulgated. The majority of violations pertained to noncompliance with the following provisions: exposure monitoring (37%), communication of hazards (23%), respiratory protection (10%), and medical surveillance (9%). However, only 200 HCS violations were attributed to potential benzene hazards in the workplace. Approximately 55% of benzene standard violations were issued to industries in the manufacturing sector, particularly those where benzene products may be used or produced (e.g., petroleum refining). The greatest percentage of violations were issued to private facility owners (90%), during inspections where union representation was present (56%), and from complaint-driven inspections (45%). Most violations involved a single instance per facility and 10 or fewer exposed employees, with initial penalties under $5,000 per violation. Many of these latter findings are consistent with OSHA inspection priorities and OSH Act stipulations.

Conclusions: Fewer than 1,000 violations of the benzene standard have been issued over the last 25+ years, compared to >80,000 violations for some other regulated substances (e.g., lead). Study limitations include a lack of information on database quality and completeness or inspections that did not result in a violation. Despite potential limitations, these data contain the best available information for assessing historical or current OSHA violations in the workplace.



Vibration Safety Assessment When Operating a Concrete Vibrator

J. Riddar and J. Karlsson, Faculty of Medicine, Lund University, Lund, Sweden

Situation/Problem: High frequency internal vibrators are used to compact concrete by removing air. The vibrators consist of a motor connected to a flexible shaft casing with a wire core and a vibrating head on the other end of the shaft. The vibrators are divided in two main categories, vibrators with handle with lengths of 1 - 1.5 m that are used for floors and ceilings and vibrators with lengths of 5 - 8 m, without handle, that are used for casting of walls. The objective was to measure the vibration levels during casting of concrete to determine the risks the concrete workers face and what actions can be taken.

Resolution: The equipment used was a vibration instrument Norsonic NOR 136 with three-axle ICP accelerometer NOR 1287. Nine short vibrators were measured at the handles during casting of concrete. Six long wall vibrators were measured, three in field tests when casting concrete and three in controlled testes. In the field tests the vibrators were measured at 0.5 m from the beginning of the, the middle and 0.5-0.25 m from the vibrating head. The controlled tests were performed with 0.1 m distance from the vibrating head continuing up to 1.50 m with the vibrator dipped in a 1000 L tank with water. One of the field tests was performed with the same distances up to 1.3 m with the vibrator immersed in sand.

Results: Vibrators with handle had an average vibration level of 1.8 m/s2 (RSD 21 %). For wall vibrators the vibration levels were on average 1.6 m/s2 (RSD 21 %) until 1.5 m from the vibrating head. Closer then 1.5 m and the vibration levels increased exponential with the distance; 1.5 m = 2.5 m/s2 (RSD 17 %); 1.0 m = 7.6 m/s2 (RSD 30 %); 0.6 m = 16.0 m/s2 (RSD 41 %); 0.3 m = 30.9 m/s2 (RSD 32 %); 0.1 m = 51.9 m/s2 (RSD 27 %) The tests performed in water were on average 2 times higher than the tests in concrete/sand.

Lessons learned: The hand arm vibrations​​​ for the vibrators with handles were below the EU action threshold of 2.5 m/s2. To avoid damaging vibrations when operating a wall vibrator, the hand grip should not be closer then 1.0 meter from the vibrating head and if possible that distance would be 1.5 m. Farther than 1.5 m from the vibrating head, the vibration levels are below the EU action threshold. We strongly recommend that the operator change to a shorter vibrator with a handle when reaching the top layer during wall casting.



Organophosphate Exposure and Depression in U.S. Air Force Aircraft Maintainers

J. Hardos and D. Ott, USAF School of Aerospace Medicine, Wright-Patterson AFB, OH; L. Whitehead, I. Han, and D. Waller, University of Texas School of Public Health, Houston, TX

Objective: Previous studies found that aircraft maintenance workers may be exposed to organophosphates in hydraulic fluid and engine oil. Studies have also illustrated a link between long-term low level organophosphate pesticide exposure and depression. The aim of this study was to measure association between self-reported workplace exposure to hydraulic fluid and engine oil and major depressive disorder.

Methods: A questionnaire containing the Patient Health Questionnaire 8 depression screener was emailed to 52,080 aircraft maintenance workers (with n=4,801 complete responses) to determine depression prevalence, severity, and descriptions of their occupational exposures. Based on a record review of workplace duties and authorized chemical usage, workers were separated into four similar exposure groups (SEGs)—propulsion, hydraulics, crew chiefs, and other workers.

Results: There was no significant difference between reported depression prevalence or severity in SEGs in which aircraft maintenance workers were exposed or may have been exposed to organophosphate esters compared to SEGs in which they were not exposed to them. However, a dichotomous measure of the prevalence of depression was significantly associated with self-reported exposure levels and with each exposure route (contact, inhalation, and ingestion). A four-level measure of depression severity was also associated with self-reported four-level categorical exposure.

Conclusions: Based on self-reported exposures and outcomes, we cannot assume that the associations we observed are causal because some workers may have been more likely to report exposure to organophosphate esters and also more likely to report depression. Future studies should consider using a larger sample size, better methods for characterizing SEGs, methods for quantifying ingestion exposure, and bioassays to measure dose rather than exposure.



An Updated Evaluation of Reported Chrysotile Asbestos: No Observed Adverse Effect Levels (NOAELs) For Lung Cancer and Mesothelioma

J. Pierce and P. Ruestow, Cardno ChemRisk, Chicago, IL; B. Finley, Cardno ChemRisk, New York City, NY

Objective: Historically, Chrysotile asbestos was used in thousands of products in the U.S. and is still used today in many countries. Therefore, it is important to understand the exposure response relationship between chrysotile and asbestos-related health effects. The purpose of this evaluation was to update an analysis published in 2008 in which we characterized chrysotile NOAELs for lung cancer and mesothelioma.

Methods: A literature search was performed to identify all epidemiology studies that described the health experience of cohorts predominantly exposed to chrysotile (< 10% amphiboles). All studies that provided risk estimates for mesothelioma or lung cancer, stratified by at least two levels of cumulative exposure, were included in our analysis. For each study, the NOAEL was defined as the highest exposure group at and below which there was no statistically significant increased risk for lung cancer and/or mesothelioma. An overall best estimate NOAEL range was estimated for each disease using the geometric mean of the lower-bound and upper-bound of the range of the NOAELs derived from each study.

Results: Sixteen lung cancer NOAELs were obtained from 14 published studies. The best estimates of the lower- and upper-bound of the NOAELs for lung cancer were 89 fibers per cubic centimeter per year (f/cc-yr.) and 168 f/cc-yr., respectively. Notably, none of the six cohorts of workers primarily exposed to medium or short fiber chrysotile exhibited an increased risk of lung cancer at any cumulative exposure level. Three cohorts were identified in which pleural mesothelioma risk was stratified according to cumulative chrysotile exposure. The best-estimates of the lower- and upper-bound of the NOAELs for pleural mesothelioma were 208 f/cc-yr. and 415 f/cc-yr., respectively.

Conclusions: This updated review reinforces our previous findings that support the existence of a cumulative exposure level for chrysotile below which lung cancer and mesothelioma risks are not appreciably raised.



Improving Safety Eyewear Fit for the US Workforce

G. Judd, J. Oh, and C. Lungu, University of Alabama at Birmingham, Birmingham, AL; P. Joe, UAB, Augusta, GA;

Situation/Problem: Safety glasses or eyewear are critical to protecting the eyes and vision of countless employees in the workplace. Safety glasses protect users from hazards such as flying objects, dust and particulate matter, and thermal energy. The protective eyewear needs to fit well and be worn consistently in order to provide adequate protection for the user. However, ill-fitting safety glasses are a common problem. The current size offerings of safety glasses do not afford protection to all the different face shapes found in the workforce.

Resolution: In 2003, NIOSH conducted a nationwide anthropometric survey of nearly four thousand subjects. The subjects’ facial features were measured using surface scans and traditional anthropometric techniques. These measurements were utilized to create five symmetric headforms that represent the facial size and shape distribution of current U.S. respirator users. The NIOSH headforms can be used to improve the fit of safety glasses by adapting safety glasses size dimensions to the shape of the headforms. Key dimensions such as temple width, earpiece length, and nose bridge height were extracted from each of the headforms and incorporated into new designs of safety glasses. Five prototype safety glasses were modeled to match the features of the NIOSH headforms and the prototypes were then manufactured using stereolithography.

Results: Full scale physical models of the five NIOSH headforms with a silicone, skin-like outer layer were used to evaluate the prototype safety glasses. Temple width, earpiece length, and nose bridge dimensions were refined in each prototype to ensure an optimal fit with the headforms. Once final prototypes were manufactured via stereolithography, each prototype was again placed on its corresponding physical model and evaluated. The final prototype safety glasses precisely matched the headforms in temple width, earpiece length, and nose placement and breadth. Photographs were taken to demonstrate the precise fit between the prototypes and headforms.

Lessons learned: The prototype safety glasses were shown to have a superior fit compared to the commercially available safety glasses. The next step in this work will be conducting a small scale trial that will evaluate eyewear fit on a diverse sample population of safety eyewear users.



Measurements of Bisphenol A in Household Dusts in Taiwan by Solid-Phase Microextraction

C. Chang, F. Hsu, Y. Hsu, P. Chang, and S. Tsai, National Taiwan University, Taipei, Taiwan

Objective: Indoor dust has been known as a sink for many semi-volatile organic compounds, such as bisphenol A (BPA). Since the indoor environment can protect dust from sunlight, rain and biological degradation, pollutants could become persistent and accumulate in the residential environment. Up to now, the analysis of BPA in dust is solvent and time consuming. Therefore, a method for the measurement of BPA in dusts simultaneously by using microwave assisted direct immersion solid-phase micro extraction (MAE-DI-SPME) has been developed to determine the distributions in Taiwan.

Methods: In this study, a commercial vacuum cleaner was used to collect household dusts while particles with diameter smaller than 150μm were filtered out by stainless mesh. Afterwards, 0.02g dust sample was spiked with 2.5 μg/g of surrogate (bisphenol A d-16) in a 4mL vial and stood for overnight. RO water of 2.5mL was added into the sample the next day, followed by the filtration and MAE-DI-SPME extraction procedures. Gas chromatograph and mass spectrometer (GC/MS) was employed for the analysis. Several parameters affecting the SPME extraction efficiency were optimized.

Results: The results showed that the desorption efficiency was 100% when the desorption time was 20 min under 250 degrees Celsius. The best suitable fiber coating was 65μm Polyethylene Glycol (PEG) and the optimum condition of MAE-DI-SPME for extraction of BPA in dust was 20 minutes at 80 degrees Celsius. The linear range for the analysis was 1.25 ~ 1250 ng/g dust (r=0.99). For indoor dust samples in Taiwan, the median, mean and rage of BPA concentrations were 4.98, 11.06 and 1.54~39.99 μg/g, respectively.

Conclusions: Relatively to headspace extraction, the established method of MAE-DI-SPME for the determination of bisphenol A in indoor dust provides good linearity and precisions. Besides, compared with traditional extraction methods, the MAE-DI-SPME provides a time saving, easy for operation and solvent free procedure.



Microbial Secondary Metabolites in Floor Dust of a Water Damaged Office Building

J. Park, CDC/NIOSH, Morgantown, WV; M. Sulyok, University of Natural Resources and Applied Life Sciences, Tulln, Austria

Objective: Exposure assessment of fungal or bacterial secondary metabolites and their health effects in occupants of water damaged buildings is an understudied area. In this study, we simultaneously measured concentrations of 501 microbial and plant secondary metabolites in 27 floor dust samples using HPLC-MS/MS (high performance liquid chromatography-tandem mass spectrometry).

Methods: The floor dust samples were collected using vacuum samplers in a water damaged office building that had sentinel cases of sarcoidosis and asthma. Approximately 30 mg of dust was extracted in solvent with high acetonitrile content (acetonitrile/water/acetic acid, 79:20:1%) using a rotary shaker for 90 minutes and 100 µl of the extract was diluted with the same volume of solvent with high water content (20:79:1%). Five µl of the final extract was injected onto HPLC for chromatographic separation of multiple analytes.

Results: We identified 32 metabolites that possibly originated from fungi, bacteria, or plants. Of these, 28 metabolites were determined to have a potential link to fungi or bacteria. Limits of detection (LOD) for these analytes ranged from 0.03 (alternariol monomethyl ether) to 75 pg/mg of dust (tenuazonic acid). Fungal and bacterial metabolites were found in more than 50% of samples, these included averufin (median concentration=0.7 pg/mg of dust), emodin (8.6), asperglaucide (23.9), usnic acid (118.9), 3-nitropropionic acid (13.4), integracin B (1.2), skyrin (7.9), integracin A (0.8), citreorosein (14.5), neoechinulin A (18.8), and alternariol monomethyl ether (0.4). Of these, averufin, emodin, asperglaucide, and usnic acid that can be produced by certain species of Aspergillus, Chaetomium, Cladosporium, Mycosphaerelia, Penicillium, and Phoma were detected in all dust samples. Although averufin (LOD=0.25 pg/mg) is one of the intermediate compounds in the biosynthetic pathway of the two well-recognized mycotoxins [sterigmatocystin (LOD=1.25) and aflatoxin B1 (LOD=1.0)] all analyzed samples were found to be below the LOD for both mycotoxins.

Conclusions: Our findings suggest that occupants in water damaged buildings may be exposed to low levels of multiple microbial secondary metabolites and that assessing exposure to those metabolites may be important in epidemiologic studies of occupants in damp buildings.​