This special issue contains a grouping of seven peer-reviewed papers that were presented at the 2016 conference on Air Quality Measurement Methods and Technology, held in Chapel Hill, NC, March 15-17, 2016. This specialty conference of the Air & Waste Management Association (A&WMA) is held approximately every 20 months, and presents advances in measurement technology and characterization on all aspects of air quality, including outdoor and indoor air quality, source emissions, and quality assurance.
While great progress has been made in measurement technologies for various pollutants, there is a greater focus on technologies and methodologies for quantifying fugitive emissions, greenhouse gases (GHG) and air toxics, improving existing techniques, and using optical and/or remote sensing techniques and low-cost sensors. The articles presented in this issue provide a good cross-section of the topics, ranging from method development and evaluation to air quality characterization near roadways and stationary sources. Two papers discuss approaches related to measurement and quantification of air emissions, primarily related to fugitive emission sources. Zeng et al. discuss methodology to further refine the quantitative optical gas imaging techniques. They demonstrate an approach to develop response factors that can be used to quantify a variety of gaseous compounds using infrared gas imagers. Fu et al. describe the design and application of a mobile platform to measure emission of GHG (carbon dioxide [CO2] and methane) in a lagoon with sufficient detection capabilities to map out the spatial and temporal profiles. This type of platform has potential applications in measuring fugitive GHG emissions from agricultural and wastewater treatment lagoons and similar water bodies.
The next two articles present an evaluation of analytical and measurement technologies. The article by Presler-Jur et al. presents a large-scale evaluation and application of optical light attenuation measurements using a robotic system of aerosol samples collected on Teflon filters. The study demonstrated the applicability of this method to estimate black carbon (BC) concentrations from Teflon filter samples, and has potential applications in expanding the historic record of BC measurements in a cost-effective manner in cases where archived Teflon filter samples are available. Leston and Ollison describe a field evaluation of “interference-free” federal reference methods (FRM) for ozone (O3) and nitrogen dioxide (NO2) that recorded on average 3 ppb and 9 ppb lower concentrations, respectively, than the conventional O3 and NO2 FRM instruments. The study also demonstrated the impact of inlet height on O3 concentrations.
The final three articles characterize air quality near roadways, schools and a power plant. Wen et al. summarize their work in measuring ultrafine particles and CO2 concentration near roadways and using it to estimate emission factor as a function of traffic volume for light duty vehicles. Brown et al. discuss measurements of particle counts and BC at schools in two different regions with urban or near-road influence, and compare the potential exposure levels. The article by Ramadan characterizes the volatile organic compounds (VOCs) present near a power plant in Kuwait. Results showed that halogenated compounds accounted for 50-75% of the total VOC measured.
I thank the conference organizers and the session chairs for encouraging the presenters to consider submitting their work for peer-reviewed publication in this special issue. I greatly appreciate the help of Dr. R.K.M. Jayanty, conference co-organizer and Emeritus Fellow at RTI International, in spreading the word about this special issue to the conference attendees. I am thankful to the authors for their effort in preparing the manuscripts for peer-reviewed publication in this issue. Finally, I am thankful to RTI International for supporting my time and effort in coordinating this special issue of the Journal.