Characterization of inhalation exposures at a wildfire incident during the Wildland Firefighter Exposure and Health Effects (WFFEHE) Study.

Wildland firefighters (WFFs) are exposed to many inhalation hazards working in the wildland fire environment. To assess occupational exposures and acute and subacute health effects among WFFs, the wildland firefighter exposure and health effects study collected data for a 2-year repeated measures study. This manuscript describes the exposure assessment from one Interagency Hotshot Crew (N = 19) conducted at a wildfire incident. Exposures to benzene, toluene, ethylbenzene, xylene isomers, formaldehyde, acetaldehyde, and naphthalene were measured through personal air sampling each work shift. Biological monitoring was done for creatinine-adjusted levoglucosan in urine pre- and post-shift. For 3 days sampling at the wildfire incident, benzene, toluene, ethylbenzene, xylene isomers (m and p, and o) exposure was highest on day 1 (geometric mean [GM] = 0.015, 0.042, 0.10, 0.42, and 0.15 ppm, respectively) when WFFs were not exposed to smoke but used chainsaws to remove vegetation and prepare fire suppression breaks. Exposure to formaldehyde and acetaldehyde was highest on day 2 (GM = 0.03 and 0.036 ppm, respectively) when the WFFs conducted a firing operation and were directly exposed to wildfire smoke. The greatest difference of pre- and post-shift levoglucosan concentrations were observed on day 3 (pre-shift: 9.7 and post-shift: 47 µg/mg creatinine) after WFFs conducted mop up (returned to partially burned area to extinguish any smoldering vegetation). Overall, 65% of paired samples (across all sample days) showed a post-shift increase in urinary levoglucosan and 5 firefighters were exposed to benzene at concentrations at or above the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit. Our findings further demonstrate that exposure to inhalation hazards is one of many risks that wildland firefighters experience while suppressing wildfires.

Evaluating Exposure to VOCs and Naphthalene for Firefighters Wearing Different PPE Configurations through Measures in Air, Exhaled Breath, and Urine.

Firefighters are at an increased risk of cancer due to their occupational exposure to combustion byproducts, especially when those compounds penetrate the firefighter personal protective equipment (PPE) ensemble. This has led to questions about the impact of base layers (i.e., shorts vs. pants) under PPE ensembles. This study asked 23 firefighters to perform firefighting activities while wearing one of three different PPE ensembles with varying degrees of protection. Additionally, half of the firefighters unzipped their jackets after the scenario while the other half kept their jackets zipped for five additional minutes. Several volatile organic compound (VOC) and naphthalene air concentrations outside and inside of hoods, turnout jackets, and turnout pants were evaluated; biological (urinary and exhaled breath) samples were also collected. VOCs and naphthalene penetrated the three sampling areas (hoods, jackets, pants). Significant (p-value < 0.05) increases from pre- to post-fire for some metabolites of VOCs (e.g., benzene, toluene) and naphthalene were found. Firefighters wearing shorts and short sleeves absorbed higher amounts of certain compounds (p-value < 0.05), and the PPE designed with enhanced interface control features appeared to provide more protection from some compounds. These results suggest that firefighters can dermally absorb VOCs and naphthalene that penetrate the PPE ensemble.

Firefighters' urinary concentrations of VOC metabolites after controlled-residential and training fire responses.

INTRODUCTION: Firefighters are exposed to volatile organic compounds (VOCs) during structural fire responses and training fires, several of which (e.g., benzene, acrolein, styrene) are known or probable carcinogens. Exposure studies have found that firefighters can absorb chemicals like benzene even when self-contained breathing apparatus (SCBA) are worn, suggesting that dermal absorption contributes to potentially harmful exposures. However, few studies have characterized VOC metabolites in urine from firefighters. OBJECTIVES: We quantified VOC metabolites in firefighters' urine following live firefighting activity across two field studies. METHODS: In two separate controlled field studies, spot urine was collected before and 3 h after firefighters and firefighter students responded to simulated residential and training fires. Urine was also collected from instructors from the training fire study before the first and 3 h after the last training scenario for each day (instructors led three training scenarios per day). Samples were analyzed for metabolites of VOCs to which firefighters may be exposed. RESULTS: In the residential fire study, urinary metabolites of xylenes (2MHA), toluene (BzMA), and styrene (MADA) increased significantly (at 0.05 level) from pre- to post-fire. In the training fire study, MADA concentrations increased significantly from pre- to post-fire for both firefighter students and instructors. Urinary concentrations of benzene metabolites (MUCA and PhMA) increased significantly from pre- to post-fire for instructors, while metabolites of xylenes (3MHA+4MHA) and acrolein (3HPMA) increased significantly for firefighter students. The two highest MUCA concentrations measured post-shift from instructors exceeded the BEI of 500 µg/g creatinine. CONCLUSIONS: Some of the metabolites that were significantly elevated post-fire are known or probable human carcinogens (benzene, styrene, acrolein); thus, exposure to these compounds should be eliminated or reduced as much as possible through the hierarchy of controls. Given stringent use of SCBA, it appears that dermal exposure contributes in part to the levels measured here.

The Wildland Firefighter Exposure and Health Effect (WFFEHE) Study: Rationale, Design, and Methods of a Repeated-Measures Study.

The wildland firefighter exposure and health effect (WFFEHE) study was a 2-year repeated-measures study to investigate occupational exposures and acute and subacute health effects among wildland firefighters. This manuscript describes the study rationale, design, methods, limitations, challenges, and lessons learned. The WFFEHE cohort included fire personnel ages 18-57 from six federal wildland firefighting crews in Colorado and Idaho during the 2018 and 2019 fire seasons. All wildland firefighters employed by the recruited crews were invited to participate in the study at preseason and postseason study intervals. In 2019, one of the crews also participated in a 3-day midseason study interval where workplace exposures and pre/postshift measurements were collected while at a wildland fire incident. Study components assessed cardiovascular health, pulmonary function and inflammation, kidney function, workplace exposures, and noise-induced hearing loss. Measurements included self-reported risk factors and symptoms collected through questionnaires; serum and urine biomarkers of exposure, effect, and inflammation; pulmonary function; platelet function and arterial stiffness; and audiometric testing. Throughout the study, 154 wildland firefighters participated in at least one study interval, while 144 participated in two or more study interval. This study was completed by the Centers for Disease Control and Prevention's National Institute for Occupational Safety and Health through a collaborative effort with the U.S. Department of Agriculture Forest Service, Department of the Interior National Park Service, and Skidmore College. Conducting research in the wildfire environment came with many challenges including collecting study data with study participants with changing work schedules and conducting study protocols safely and operating laboratory equipment in remote field locations. Forthcoming WFFEHE study results will contribute to the scientific evidence regarding occupational risk factors and exposures that can impact wildland firefighter health over a season and across two wildland fire seasons. This research is anticipated to lead to the development of preventive measures and policies aimed at reducing risk for wildland firefighters and aid in identifying future research needs for the wildland fire community.

Characterizing exposures to flame retardants, dioxins, and furans among firefighters responding to controlled residential fires.

Firefighters may encounter items containing flame retardants (FRs), including organophosphate flame retardants (OPFRs) and polybrominated diphenyl ethers (PBDEs), during structure fires. This study utilized biological monitoring to characterize FR exposures in 36 firefighters assigned to interior, exterior, and overhaul job assignments, before and after responding to controlled residential fire scenarios. Firefighters provided four urine samples (pre-fire and 3-h, 6-h, and 12-h post-fire) and two serum samples (pre-fire and approximately 23-h post-fire). Urine samples were analyzed for OPFR metabolites, while serum samples were analyzed for PBDEs, brominated and chlorinated furans, and chlorinated dioxins. Urinary concentrations of diphenyl phosphate (DPhP), a metabolite of triphenyl phosphate (TPhP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), a metabolite of tris(1,3-dichloro-2-propyl) phosphate (TDCPP), and bis(2-chloroethyl) phosphate (BCEtP), a metabolite of tris(2-chloroethyl) phosphate (TCEP), increased from pre-fire to 3-hr and 6-hr post-fire collection, but only the DPhP increase was statistically significant at a 0.05 level. The 3-hr and 6-hr post-fire concentrations of DPhP and BDCPP, as well as the pre-fire concentration of BDCPP, were statistically significantly higher than general population levels. BDCPP pre-fire concentrations were statistically significantly higher in firefighters who previously participated in a scenario (within the past 12 days) than those who were responding to their first scenario as part of the study. Similarly, firefighters previously assigned to interior job assignments had higher pre-fire concentrations of BDCPP than those previously assigned to exterior job assignments. Pre-fire serum concentrations of 2,3,4,7,8-pentachlorodibenzofuran (23478-PeCDF), a known human carcinogen, were also statistically significantly above the general population levels. Of the PBDEs quantified, only decabromodiphenyl ether (BDE-209) pre- and post-fire serum concentrations were statistically significantly higher than the general population. These results suggest firefighters absorbed certain FRs while responding to fire scenarios.

Association of occupational exposures with ex vivo functional immune response in workers handling carbon nanotubes and nanofibers.

The objective of this study was to evaluate the association between carbon nanotube and nanofiber (CNT/F) exposure and ex vivo responses of whole blood challenged with secondary stimulants, adjusting for potential confounders, in a cross-sectional study of 102 workers. Multi-day exposure was measured by CNT/F structure count (SC) and elemental carbon (EC) air concentrations. Demographic, lifestyle and other occupational covariate data were obtained via questionnaire. Whole blood collected from each participant was incubated for 18 hours with and without two microbial stimulants (lipopolysaccharide/LPS and staphylococcal enterotoxin type B/SEB) using TruCulture technology to evaluate immune cell activity. Following incubation, supernatants were preserved and analyzed for protein concentrations. The stimulant:null response ratio for each individual protein was analyzed using multiple linear regression, followed by principal component (PC) analysis to determine whether patterns of protein response were related to CNT/F exposure. Adjusting for confounders, CNT/F metrics (most strongly, the SC-based) were significantly (p < 0.05) inversely associated with stimulant:null ratios of several individual biomarkers: GM-CSF, IFN-γ, interleukin (IL)-2, IL-4, IL-5, IL-10, IL-17, and IL-23. CNT/F metrics were significantly inversely associated with PC1 (a weighted mean of most biomarkers, explaining 25% of the variance in the protein ratios) and PC2 (a biomarker contrast, explaining 14%). Among other occupational exposures, only solvent exposure was significant (inversely related to PC2). CNT/F exposure metrics were uniquely related to stimulant responses in challenged whole blood, illustrating reduced responsiveness to a secondary stimulus. This approach, if replicated in other exposed populations, may present a relatively sensitive method to evaluate human response to CNT/F or other occupational exposures.

Firefighters' absorption of PAHs and VOCs during controlled residential fires by job assignment and fire attack tactic.

To better understand the absorption of combustion byproducts during firefighting, we performed biological monitoring (breath and urine) on firefighters who responded to controlled residential fires and examined the results by job assignment and fire attack tactic. Urine was analyzed for metabolites of polycyclic aromatic hydrocarbons (PAHs) and breath was analyzed for volatile organic compounds (VOCs) including benzene. Median concentrations of PAH metabolites in urine increased from pre-firefighting to 3-h post firefighting for all job assignments. This change was greatest for firefighters assigned to attack and search with 2.3, 5.6, 3.9, and 1.4-fold median increases in pyrene, phenanthrene, naphthalene, and fluorene metabolites. Median exhaled breath concentrations of benzene increased 2-fold for attack and search firefighters (p < 0.01) and 1.4-fold for outside vent firefighters (p = 0.02). Compared to interior attack, transitional attack resulted in 50% less uptake of pyrene (p = 0.09), 36% less uptake phenanthrene (p = 0.052), and 20% less uptake of fluorene (p < 0.01). Dermal absorption likely contributed to firefighters' exposures in this study. Firefighters' exposures will vary by job assignment and can be reduced by employing a transitional fire attack when feasible.

Firefighters' and instructors' absorption of PAHs and benzene during training exercises.

INTRODUCTION: Training fires may constitute a major portion of some firefighters' occupational exposures to smoke. However, the magnitude and composition of those exposures are not well understood and may vary by the type of training scenario and fuels. OBJECTIVES: To understand how structure fire training contributes to firefighters' and instructors' select chemical exposures, we conducted biological monitoring during exercises involving combustion of pallet and straw and oriented strand board (OSB) or the use of simulated smoke. METHODS: Urine was analyzed for metabolites of polycyclic aromatic hydrocarbons (PAHs) and breath was analyzed for volatile organic compounds (VOCs) including benzene. RESULTS: Median concentrations of nearly all PAH metabolites in urine increased from pre-to 3-hr post-training for each scenario and were highest for OSB, followed by pallet and straw, and then simulated smoke. For instructors who supervised three trainings per day, median concentrations increased at each collection. A single day of OSB exercises led to a 30-fold increase in 1-hydroxypyrene for instructors, culminating in a median end-of-shift concentration 3.5-fold greater than median levels measured from firefighters in a previous controlled-residential fire study. Breath concentrations of benzene increased 2 to 7-fold immediately after the training exercises (with the exception of simulated smoke training). Exposures were highest for the OSB scenario and instructors accumulated PAHs with repeated daily exercises. CONCLUSIONS: Dermal absorption likely contributed to the biological levels as the respiratory route was well protected. Training academies should consider exposure risks as well as instructional objectives when selecting training exercises.

Field evaluation of onsite near real-time monitors for surface contamination by 5-fluorouracil.

OBJECTIVES: In order to produce near real-time onsite results to detect surface contamination by antineoplastic drugs, the National Institute for Occupational Safety and Health developed monitors for 5-fluorouracil, which use surface wiping and lateral flow immunoassay for measurement. The monitors were tested in the laboratory to assess the sensitivity of detection on laboratory-produced contaminated surfaces. A field evaluation to assess the capability of the monitors to make measurements in healthcare workplaces was carried out in collaboration with a medical device company and the results are presented in this report. METHODS: The 5-fluorouracil monitor was evaluated in areas where oncology drugs were prepared and administered to patients at five different hospitals. The levels of contamination measured with the monitors were compared to levels measured with liquid chromatography-tandem mass spectrometry. RESULTS: The 5-fluorouracil values measured with the liquid chromatography-tandem mass spectrometry ranged from 0 to over 200,000 ng/100 cm2. Measurements by the 5-fluorouracil monitors in the range 10-100 ng/100 cm2 correlated with the liquid chromatography-tandem mass spectrometry. Receiver operating characteristic curves developed for the data indicated that a positive limit of 22 ng/100 cm2 would give an acceptable level of false-positives while retaining most true-positive samples. If the liquid chromatography-tandem mass spectrometry measured greater than 100 ng/100 cm2, then the monitors also measured levels greater than 100 ng/100 cm2 for the majority of samples. CONCLUSION: The data indicate that there are many areas in hospitals that are contaminated with 5-fluorouracil and the monitors will be useful in identifying this contamination.

Contamination of firefighter personal protective equipment and skin and the effectiveness of decontamination procedures.

Firefighters' skin may be exposed to chemicals via permeation/penetration of combustion byproducts through or around personal protective equipment (PPE) or from the cross-transfer of contaminants on PPE to the skin. Additionally, volatile contaminants can evaporate from PPE following a response and be inhaled by firefighters. Using polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) as respective markers for non-volatile and volatile substances, we investigated the contamination of firefighters' turnout gear and skin following controlled residential fire responses. Participants were grouped into three crews of twelve firefighters. Each crew was deployed to a fire scenario (one per day, four total) and then paired up to complete six fireground job assignments. Wipe sampling of the exterior of the turnout gear was conducted pre- and post-fire. Wipe samples were also collected from a subset of the gear after field decontamination. VOCs off-gassing from gear were also measured pre-fire, post-fire, and post-decon. Wipe sampling of the firefighters' hands and neck was conducted pre- and post-fire. Additional wipes were collected after cleaning neck skin. PAH levels on turnout gear increased after each response and were greatest for gear worn by firefighters assigned to fire attack and to search and rescue activities. Field decontamination using dish soap, water, and scrubbing was able to reduce PAH contamination on turnout jackets by a median of 85%. Off-gassing VOC levels increased post-fire and then decreased 17-36 min later regardless of whether field decontamination was performed. Median post-fire PAH levels on the neck were near or below the limit of detection (< 24 micrograms per square meter [µg/m2]) for all positions. For firefighters assigned to attack, search, and outside ventilation, the 75th percentile values on the neck were 152, 71.7, and 39.3 µg/m2, respectively. Firefighters assigned to attack and search had higher post-fire median hand contamination (135 and 226 µg/m2, respectively) than other positions (< 10.5 µg/m2). Cleansing wipes were able to reduce PAH contamination on neck skin by a median of 54%.

Detection and measurement of surface contamination by multiple antineoplastic drugs using multiplex bead assay.

OBJECTIVES: Contamination of workplace surfaces by antineoplastic drugs presents an exposure risk for healthcare workers. Traditional instrumental methods to detect contamination such as liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) are sensitive and accurate but expensive. Since immunochemical methods may be cheaper and faster than instrumental methods, we wanted to explore their use for routine drug residue detection for preventing worker exposure. METHODS: In this study we examined the feasibility of using fluorescence covalent microbead immunosorbent assay (FCMIA) for simultaneous detection and semi-quantitative measurement of three antineoplastic drugs (5-fluorouracil, paclitaxel, and doxorubicin). The concentration ranges for the assay were 0-1000 ng/ml for 5-fluorouracil, 0-100 ng/ml for paclitaxel, and 0-2 ng/ml for doxorubicin. The surface sampling technique involved wiping a loaded surface with a swab wetted with wash buffer, extracting the swab in storage/blocking buffer, and measuring drugs in the extract using FCMIA. RESULTS: There was no significant cross-reactivity between these drugs at the ranges studied indicated by a lack of response in the assay to cross analytes. The limit of detection (LOD) for 5-fluorouracil on the surface studied was 0.93 ng/cm(2) with a limit of quantitation (LOQ) of 2.8 ng/cm(2), the LOD for paclitaxel was 0.57 ng/cm(2) with an LOQ of 2.06 ng/cm(2), and the LOD for doxorubicin was 0.0036 ng/cm(2) with an LOQ of 0.013 ng/cm(2). CONCLUSION: The use of FCMIA with a simple sampling technique has potential for low cost simultaneous detection and semi-quantitative measurement of surface contamination from multiple antineoplastic drugs.

Detection of 5-fluorouracil surface contamination in near real time.

OBJECTIVES: Contamination of workplace surfaces by antineoplastic drugs presents an exposure risk for healthcare workers. Traditional instrumental methods to detect contamination such as gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) are sensitive and accurate but expensive and incapable of producing results in real time. This limits their utility in preventing worker exposure. We are currently developing monitors based on lateral flow immunoassay that can detect drug contamination in near real time. In this report, we describe the laboratory performance of a 5-fluorouracil (5-FU) monitor. METHODS: The monitor was evaluated by spiking ceramic, vinyl, composite, stainless steel, and glass surfaces of 100 cm(2) area with 5-FU masses of 0, 5, 10, 25, 50, and 100 ng. The surface was sampled with a wetted cotton swab, the swab was extracted with buffer, and the resulting solution was applied to a lateral flow monitor. Two ways of evaluating the response of these monitors were used: an electronic method where a lateral flow reader was used for measuring line intensities, and a visual method where the intensity of the test line was visually compared to the control line. RESULTS: The 5-FU monitor is capable of detecting 10 ng/100 cm(2) (0.1 ng/cm(2)) using the electronic reader and 25 ng/100 cm(2) (0.25 ng/cm(2)) using the visual comparison method for the surfaces studied. The response of the monitors was compared to LC-MS/MS results for the same samples for validation and there was good correlation of the two methods but some differences in absolute response, especially at higher spiking levels for the surface samples.

Enhanced performance of methamphetamine lateral flow cassettes using an electronic lateral flow reader.

Surface contamination from methamphetamine in meth labs continues to be a problem. We had previously developed a lateral flow assay cassette for field detection of methamphetamine contamination that is commercially available and has been used by a number of groups to assess contamination. This cassette uses the complete disappearance of the test line as an end point for detection of 50 ng/100 cm2 of methamphetamine contamination for surface sampling with cotton swabs. In the present study, we further evaluate the response of the cassettes using an electronic lateral flow reader to measure the intensities of the test and control lines. The cassettes were capable of detecting 0.25 ng/ml for calibration solutions. For 100 cm2 ceramic tiles that were spiked with methamphetamine and wiped with cotton-tipped wooden swabs wetted in assay/sampling buffer, 1 ng/tile was detected using the reader. Semi-quantitative results can be produced over the range 0-10 ng/ml for calibration solutions and 0-25 ng/tile for spiked tiles using either a 4-parameter logistic fit of test line intensity versus concentration or spiked mass or the ratio of the control line to the test line intensity fit to concentration or spiked mass. Recovery from the tiles was determined to be about 30% using the fitted curves. Comparison of the control line to the test line was also examined as a possible visual detection end point and it was found that the control line became more intense than the test line at 0.5 to 1 ng/ml for calibration solutions or 1 to 2 ng/tile for spiked tiles. Thus the lateral flow cassettes for methamphetamine have the potential to produce more sensitive semi-quantitative results if an electronic lateral flow reader is used and can be more sensitive for detection if the comparison of the control line to the test line is used as the visual end point.

Systemic exposure to PAHs and benzene in firefighters suppressing controlled structure fires.

Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination. To ensure that any increase in systemic PAH levels after the burn was the result of dermal rather than inhalation exposure, the firefighters did not remove their self-contained breathing apparatus until overhaul was completed and they were >30 m upwind from the burn structure. Specimens were collected before and at intervals after the burn for biomarker analysis. Urine was analyzed for phenanthrene equivalents using enzyme-linked immunosorbent assay and a benzene metabolite (s-phenylmercapturic acid) using liquid chromatography/tandem mass spectrometry; both were adjusted by creatinine. Exhaled breath collected on thermal desorption tubes was analyzed for PAHs and other aromatic hydrocarbons using gas chromatography/mass spectrometry. We collected personal air samples during the burn and skin wipe samples (corn oil medium) on several body sites before and after the burn. The air and wipe samples were analyzed for PAHs using a liquid chromatography with photodiode array detection. We explored possible changes in external exposures or biomarkers over time and the relationships between these variables using non-parametric sign tests and Spearman tests, respectively. We found significantly elevated (P < 0.05) post-exposure breath concentrations of benzene compared with pre-exposure concentrations for both rounds. We also found significantly elevated post-exposure levels of PAHs on the neck compared with pre-exposure levels for round 1. We found statistically significant positive correlations between external exposures (i.e. personal air concentrations of PAHs) and biomarkers (i.e. change in urinary PAH metabolite levels in round 1 and change in breath concentrations of benzene in round 2). The results suggest that firefighters wearing full protective ensembles absorbed combustion products into their bodies. The PAHs most likely entered firefighters' bodies through their skin, with the neck being the primary site of exposure and absorption due to the lower level of dermal protection afforded by hoods. Aromatic hydrocarbons could have been absorbed dermally during firefighting or inhaled during the doffing of gear that was off-gassing contaminants.

Using urinary biomarkers of polycyclic aromatic compound exposure to guide exposure-reduction strategies among asphalt paving workers.

INTRODUCTION: Paving workers are exposed to polycyclic aromatic compounds (PACs) while working with hot-mix asphalt (HMA). Further characterization of the source and route of these exposures is necessary to guide exposure-reduction strategies. METHODS: Personal air (n=144), hand-wash (n=144), and urine (n=480) samples were collected from 12 paving workers over 3 workdays during 4 workweeks. Urine samples were collected at preshift, postshift, and bedtime and analyzed for 10 hydroxylated PACs (1-OH-pyrene; 1-, 2-, 3-, 4-OH-phenanthrene; 1-, 2-OH-naphthalene; 2-, 3-, 9-OH-fluorene) by an immunochemical quantification of PACs (I-PACs). The air and hand-wash samples were analyzed for the parent compounds corresponding to the urinary analytes. Using a crossover study design, each of the 4 weeks represented a different exposure scenario: a baseline week (normal conditions), a dermal protection week (protective clothing), a powered air-purifying respirator (PAPR) week, and a biodiesel substitution week (100% biodiesel provided to replace the diesel oil normally used by workers to clean tools and equipment). The urinary analytes were analyzed using linear mixed-effects models. RESULTS: Postshift and bedtime concentrations were significantly higher than preshift concentrations for most urinary biomarkers. Compared with baseline, urinary analytes were reduced during the dermal protection (29% for 1-OH-pyrene, 15% for I-PACs), the PAPR (24% for 1-OH-pyrene, 15% for I-PACs), and the biodiesel substitution (15% for 1-OH-pyrene) weeks. The effect of PACs in air was different by exposure scenario (biodiesel substitution>dermal protection>PAPR and baseline) and was still a significant predictor of most urinary analytes during the week of PAPR use, suggesting that PACs in air were dermally absorbed. The application temperature of HMA was positively associated with urinary measures, such that an increase from the lowest application temperature (121°C) to the highest (154°C) was associated with a 72% increase in ΣOH-fluorene and 1-OH-pyrene and an 82% increase in ΣOH-phenanthrene. Though PACs in hand-wash samples were not predictors of urinary analytes, the effects observed during the PAPR scenario and the week of increased dermal protection provide evidence of dermal absorption. CONCLUSIONS: Our results provide evidence that PACs in air are dermally absorbed. Reducing the application temperature of asphalt mix appears to be a promising strategy for reducing PAC exposure among paving workers. Additional reductions may be achieved by requiring increased dermal coverage of workers and by substituting biodiesel for diesel oil as a cleaning agent.

Semi-quantitative analysis of influenza samples using the Luminex xTAG(®) respiratory viral panel kit.

The Luminex xTAG(®) respiratory viral panel (RVP) kit simultaneously detects and identifies multiple respiratory viruses including several subtypes of influenza A using a multiplex nucleic acid amplification test assay platform. The emitted fluorescence signal from the RVP assay provides qualitative information on the presence of a particular viral species in respiratory specimens. However, a quantitative assessment is preferred when monitoring environmental samples for respiratory viruses. In this study, we explored the potential use of the RVP kit as a semi-quantitative screening assay for influenza virus detection. The concentration- response of the RVP assay was modeled using four-parameter logistic (4-PL) fits of mean fluorescence intensity (MFI) versus dilute ranges of the influenza A matrix gene, seasonal influenza vaccine, and 2009 H1N1 influenza vaccine. The goodness of fit of the 4-PL model was evaluated by comparing the copy number determined with the fitted model (observed copy number) with the copy number calculated from the dilution of the matrix DNA or vaccine (expected copy number). For the matrix DNA and 2009 H1N1 vaccine, the 4-PL model provided good fit for the influenza A RVP assay response over factors of 10(3) to 10(4). For seasonal influenza vaccine, the model provided good fit for RVP assay response to influenza A, influenza B, H1, and H3.

A pilot study of workplace dermal exposures to cypermethrin at a chemical manufacturing plant.

Exposure during the manufacture of pesticides is of particular concern due to their toxicity and because little is known about worker exposure, since most studies have focused on end-use application within agriculture or buildings. Even though dermal exposure can be expected to dominate for pesticides, little is known about workplace dermal exposures or even appropriate methods for their assessment. The current study begins to address this gap by evaluating alternative methods for assessing dermal exposure at a chemical manufacturing plant. For this pilot study, eight workers were recruited from a U.S. plant that produced the pesticide cypermethrin. Exposure was evaluated using three approaches: (1) survey assessment (questionnaire), (2) biological monitoring, and (3) workplace environmental sampling including ancillary measurements of glove contamination (interior and exterior). In each case, cypermethrin was quantified by enzyme-linked immunosorbent assay (ELISA). Environmental measurements identified two potential pathways of cypermethrin exposure: glove and surface contamination. Workplace exposure was also indicated by urine levels (specific gravity adjusted) of the parent compound, which ranged from 35 to 253 µg/L (median of 121 µg/L) with no clear trend in levels from pre- to post-shift. An exploratory analysis intended to guide future studies revealed a positive predictive association (Spearman correlation, p ≤ 0.10) between post-shift urine concentrations and a subset of survey questions evaluating worker knowledge, attitudes, and perceptions (KAP) of workplace dermal hazards, i.e., personal protective equipment self-efficacy, and inverse associations with behavior belief and information belief scales. These findings are valuable in demonstrating a variety of dermal exposure methods (i.e., behavioral attributes, external contamination, and biomarker) showing feasibility and providing measurement ranges and preliminary associations to support future and more complete assessments. Although these pilot data are useful for supporting design and sample size considerations for larger exposure and health studies, there is a need for validation studies of the ELISA assay for quantification of cypermethrin and its metabolites in urine.

Measurement of multiple drugs in urine, water, and on surfaces using fluorescence covalent microbead immunosorbent assay.

There are a range of applications that require the measurement of multiple drugs such as urine analysis, drug determination in water, and screening for drug contamination on surfaces. Some of the procedures used such as enzyme-linked immunosorbent assay (ELISA) are simple but can only determine one drug at a time, and others such as GC-MS or LC-MS are complex, time-consuming, and expensive. In this study, fluorescence covalent microbead immunosorbent assay (FCMIA) was investigated as a simple method for the measurement of multiple drugs simultaneously in three matrices: diluted urine, water, and on surfaces. Five different drugs of abuse or their metabolites (methamphetamine, caffeine, benzoylecgonine (a metabolite of cocaine), tetrahydrocannabinol (THC), the active ingredient in marijuana, and oxycodone) were studied over the range 0-15 ng/ml. There was no measureable cross-reactivity among the drugs at the concentrations studied. Urine dilutions from 1/50 to 1/2.5 were studied and dilutions less than 1/20 had a significant effect on the methamphetamine assay but limited effects on the benzoylecgonine and oxycodone assays and almost no effect on the THC assay. For assays performed in 1/20 urine dilution, water, and diluted surface sampling buffer, least detectable doses (LDD) were 1 ng/ml or less for the drugs. Surfaces spiked with drugs were sampled with swabs wetted with surface sampling buffer and recoveries were linear over the range 0-100 ng/100 cm(2) surface loading for all drugs. FCMIA has potential to be used for the measurement of multiple drugs in the matrices studied.

Interlaboratory comparison of three multiplexed bead-based immunoassays for measuring serum antibodies to pneumococcal polysaccharides.

Serotype-specific IgG, as quantified by a standardized WHO enzyme-linked immunosorbent assay (ELISA), is a serologic end point used to evaluate pneumococcal polysaccharide-based vaccine immunogenicity. Antibodies to each vaccine polysaccharide in licensed multivalent vaccines are quantified separately; this is laborious and consumes serum. We compared three bead-based immunoassays: a commercial assay (xMAP Pneumo14; Luminex) and two in-house assays (of the Health Protection Agency [HPA] and Centers for Disease Control and Prevention [CDC]), using the WHO-recommended standard reference and reference sera (n = 11) from vaccinated adults. Multiple comparisons of the IgG concentrations for seven conjugate vaccine serotypes were performed by sample (percent error), serotype (equivalency testing), and laboratory (concordance correlation coefficient [CCC]). When comparing concentrations by sample, bead-based immunoassays generally yielded higher antibody concentrations than the ELISA and had higher variability for serotypes 6B, 18C, and 23F. None of the three assays met the current WHO recommendation of 75% of sera falling within 40% of the assigned antibody concentrations for all seven serotypes. When compared by serotype, the CDC and HPA tests were equivalent for five of seven serotypes, whereas the Luminex assay was equivalent for four of seven serotypes. When overall mean IgG concentrations were compared by laboratory, a higher level of agreement (CCC close to 1) was found among bead-based immunoassays than between the assays and WHO assignments. When compared to WHO assignments, the HPA assay outperformed the other assays (r = 0.920; CCC = 0.894; coefficient of accuracy = 0.972). Additional testing with sera from immunogenicity studies should demonstrate the applicability of this methodology for vaccine evaluation.

A pilot respiratory health assessment of nail technicians: symptoms, lung function, and airway inflammation.

BACKGROUND: Recent surveys suggest nail technicians, particularly artificial nail applicators, have increased respiratory symptoms and asthma risk. METHODS: We examined lung function (n = 62) and a marker of airway inflammation, i.e., exhaled nitric oxide (ENO) (n = 43), in a subset of nail technician and control participants in a pilot health assessment. RESULTS: Bivariate analysis of technicians demonstrated that job latency was inversely correlated with FEV1 percent predicted (FEV1PP) (r = -0.34, P = 0.03) and FVCPP (r = -0.32, P = 0.05). Acrylic gel contact hours were inversely correlated with FEV1PP (r = -0.38, P = 0.02) and FVCPP (r = -0.47, P = 0.003). Current smoking was inversely and significantly (P