Additional Funding Sources
This project is supported by a 2020-2021 STEM Undergraduate Research Grant from the Higher Education Research Council and an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under Grant No. P20GM103408.
Presentation Date
7-2021
Abstract
Risk to human health due to air toxics exposure can be best assessed using time-weighted averages of various compound concentrations. These average concentrations are delivered by passive sampling techniques, which requires diffusive uptake rates (UTRs) for analysis. The use of these samplers is advantageous as a result of versatility in sampling duration, low costs of operation, and ease of use. Supplementing a current shortage of UTRs for samplers containing Tenax®TA, a parallel active and passive air sampling method was used to determine UTRs for 27 VOCs, including known carcinogens such as BTEX compounds, hydrocarbons, and terpenes. These rates were measured for 24-hour, 7, 14, and 28-day sampling durations to accommodate the wide time range for which passive samplers can be employed. All analysis of samples was completed by thermal desorption-gas chromatography-mass spectrometry. The applicability of the UTRs measured here was demonstrated by retrospective analysis of VOC data from the 2019 NASA/NOAA Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign. This field study examined smoke composition from wildfires in the United States. The concentrations derived from UTRs determined in this study were subsequently used to assess human health risk from exposure to fire emissions measured during FIREX-AQ. Limited fire activity in 2019 led to low exposure to carcinogenic VOCs, but the UTRs determined here are equally applicable to any employment of diffusive sampling.
Analysis of Diffusive Rates for Use with Air Toxic Risk Assessment
Risk to human health due to air toxics exposure can be best assessed using time-weighted averages of various compound concentrations. These average concentrations are delivered by passive sampling techniques, which requires diffusive uptake rates (UTRs) for analysis. The use of these samplers is advantageous as a result of versatility in sampling duration, low costs of operation, and ease of use. Supplementing a current shortage of UTRs for samplers containing Tenax®TA, a parallel active and passive air sampling method was used to determine UTRs for 27 VOCs, including known carcinogens such as BTEX compounds, hydrocarbons, and terpenes. These rates were measured for 24-hour, 7, 14, and 28-day sampling durations to accommodate the wide time range for which passive samplers can be employed. All analysis of samples was completed by thermal desorption-gas chromatography-mass spectrometry. The applicability of the UTRs measured here was demonstrated by retrospective analysis of VOC data from the 2019 NASA/NOAA Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign. This field study examined smoke composition from wildfires in the United States. The concentrations derived from UTRs determined in this study were subsequently used to assess human health risk from exposure to fire emissions measured during FIREX-AQ. Limited fire activity in 2019 led to low exposure to carcinogenic VOCs, but the UTRs determined here are equally applicable to any employment of diffusive sampling.