Dataset of polycyclic aromatic hydrocarbon recoveries from a selection of sorbent tubes for thermal desorption-gas chromatography/mass spectrometry analysis.

This dataset contains raw area counts and percent recoveries of polycyclic aromatic hydrocarbon (PAH) standards desorbed from selected sorbent tubes and analyzed using thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). The results of this study were published in the article "Recovery and reactivity of polycyclic aromatic hydrocarbons collected on selected sorbent tubes and analyzed by thermal desorption-gas chromatography/mass spectrometry" in Journal of Chromatography A [1]. The sorbent tubes studied include stainless steel Carbograph 2TD/1TD, glass quartz wool-Carbograph 2TD, inert-coated stainless steel Carbograph 2TD, glass and stainless steel Tenax TA, PAH (chemical weapons), and glass and stainless steel XRO-440 sorbent tubes. Tables listing the experimental conditions, TD methods, and types of sorbent tubes are included in the manuscript. Data for experiments, including the investigation of incomplete desorption of PAHs from Carbograph 2TD/1TD and XRO-440 sorbent tubes, the comparison of PAH recoveries from three different TD methods, the analysis of PAH breakthrough from sorbent tubes, the investigation of the effect of heat on PAH percent recovery from sorbent tubes, and the formation of reaction products during PAH loading and desorption are included in Appendix A. These data can be used to guide sorbent tube selection for PAH analyses in future studies.

Recovery and reactivity of polycyclic aromatic hydrocarbons collected on selected sorbent tubes and analyzed by thermal desorption-gas chromatography/mass spectrometry.

This article describes the optimization of methodology for extending the measurement of volatile organic compounds (VOCs) to increasingly heavier polycyclic aromatic hydrocarbons (PAHs) with a detailed focus on recent sorbent tube technology. Although PAHs have lower volatility than compounds such as benzene, toluene, ethylbenzene and xylenes, these semi-volatile compounds can be detected in air and breath samples. For this work, PAHs were captured on sorbent tubes and subsequently analyzed using automated thermal desorption gas chromatography - mass spectrometry (ATD-GC/MS). While many different sorbent tubes are commercially available, optimization for airborne PAH sampling using sorbent tubes has not been previously considered. Herein, several commercially available sorbent tubes, including Carbograph 2 TD/1TD, Tenax TA, XRO-440, and inert-coated PAH tubes are compared to determine the relative recovery for eight PAHs commonly found in the environment. Certain types of sorbent materials were found to be better suited for PAH recovery during thermal desorption, and PAH reaction products were observed on several types of sorbent tubes, including graphitized carbon black sorbents with stainless steel tube materials. As such, selection of sorbent tube media should be carefully considered prior to embarking on a PAH study.

Targeted GC-MS analysis of firefighters' exhaled breath: Exploring biomarker response at the individual level.

Biomarker measurements can provide unambiguous evidence of environmental exposures as well as the resultant biological responses. Firefighters have a high rate of occupational cancer incidence, which has been proposed to be linked in part to their increased environmental exposure to byproducts of combustion and contaminants produced during fire responses. In this article, the uptake and elimination of targeted volatile organic compounds were investigated by collecting the exhaled breath of firefighters on sorbent tubes before and after controlled structure burns and analyzing samples using automated thermal desorption-gas chromatography (ATD-GC/MS). Volatile organic compounds exposure was assessed by grouping the data according to firefighting job positions as well as visualizing the data at the level of the individual firefighter to determine which individuals had expected exposure responses. When data were assessed at the group level, benzene concentrations were found to be elevated post-exposure in both fire attack, victim search, and outside ventilation firefighting positions. However, the results of the data analysis at the individual level indicate that certain firefighters may be more susceptible to post-exposure volatile organic compounds increases than others, and this should be considered when assessing the effectiveness of firefighting protective gear. Although this work focuses on firefighting activity, the results can be translated to potential human health and ecological effects from building and forest fires.

Volatile organic compounds at two oil and natural gas production well pads in Colorado and Texas using passive samplers.

UNLABELLED: A pilot study was conducted in application of the U.S. Environmental Protection Agency (EPA) Methods 325A/B variant for monitoring volatile organic compounds (VOCs) near two oil and natural gas (ONG) production well pads in the Texas Barnett Shale formation and Colorado Denver-Julesburg Basin (DJB), along with a traffic-dominated site in downtown Denver, CO. As indicated in the EPA method, VOC concentrations were measured for 14-day sampling periods using passive-diffusive tube samplers with Carbopack X sorbent at fenceline perimeter and other locations. VOCs were significantly higher at the DJB well pad versus the Barnett well pad and were likely due to higher production levels at the DJB well pad during the study. Benzene and toluene were significantly higher at the DJB well pad versus downtown Denver. Except for perchloroethylene, VOCs measured at passive sampler locations (PSs) along the perimeter of the Barnett well pad were significantly higher than PSs farther away. At the DJB well pad, most VOC concentrations, except perchloroethylene, were significantly higher prior to operational changes than after these changes were made. Though limited, the results suggest passive samplers are precise (duplicate precision usually ≤10%) and that they can be useful to assess spatial gradients and operational conditions at well pad locations over time-integrated periods. IMPLICATIONS: Recently enacted EPA Methods 325A/B use passive-diffusive tube samplers to measure benzene at multiple fenceline locations at petrochemical refineries. This pilot study presents initial data demonstrating the utility of Methods 325A/B for monitoring at ONG facilities. Measurements revealed elevated concentrations reflective of production levels and spatial gradients of VOCs relative to source proximity at the Barnett well pad, as well as operational changes at the DJB well pad. Though limited, these findings indicate that Methods 325A/B can be useful in application to characterize VOCs at well pad boundaries.

Methodologies for estimating cumulative human exposures to current-use pyrethroid pesticides.

We estimated cumulative residential pesticide exposures for a group of nine young children (4-6 years) using three different methodologies developed by the US Environmental Protection Agency and compared the results with estimates derived from measured urinary metabolite concentrations. The Standard Operating Procedures (SOPs) for Residential Exposure Assessment are intended to provide a screening-level assessment to estimate exposure for regulatory purposes. Nonetheless, dermal exposure estimates were typically lower from the SOP (1-1300 nmol/day) than from SHEDS (5-19,000 nmol/day) or any of the four different approaches for estimating dermal exposure using the Draft Protocol for Measuring Children's Non-Occupational Exposure to Pesticides by all Relevant Pathways (Draft Protocol) (5-11,000 nmol/day). Indirect ingestion exposure estimates ranged from 0.02 to 21.5 nmol/day for the SOP, 0.5 to 188 nmol/day for SHEDS, and 0 to 3.38 nmol/day for the Draft Protocol. Estimates of total absorbed dose ranged from 3 to 37 nmol/day for the SOPs, 0.5 to 100 nmol/day for SHEDS, and 1 to 216 nmol/day for the Draft Protocol. The concentrations estimated using the Draft Protocol and SHEDS showed strong, positive relationships with the 3-phenoxybenzoic acid metabolite measured in the children's urine samples (R²=0.90 for the Draft Protocol; R²=0.92 for SHEDS). Analysis of different approaches for estimating dermal exposure suggested that the approach assuming an even distribution of pesticide residue on the child's body was most reasonable. With all three methodologies providing reasonable estimates of exposure and dose, selection should depend on the available data and the objectives of the analysis. Further research would be useful to better understand how best to estimate dermal exposure for children and what exposure factors (e.g., activities, transfer coefficients, measurement techniques) are most relevant in making dermal exposure estimates.