A formaldehyde and nitrogen dioxide toxics monitor for environmental justice

DOEĺs Integrated Field Laboratories require a vast array of measurements to better characterize urban air quality and further environmental justice goals. Nitrogen dioxide and formaldehyde are ubiquitous pollutants with numerous sources, most notably vehicle exhaust in urban areas. High-spatial density measurements in urban environments are critical to understanding environmental justice issues, as certain neighborhoods are more adversely impacted by pollutants. This project will develop a rapid, affordable, low-power monitor to provide high spatial resolution mobile measurements of formaldehyde and nitrogen dioxide at street-level, where people live and walk. The spatial density will be achieved via rapid measurements on a mobile platform. This sensor will quantify spatial disparities of the toxics HCHO and NO2 in cities, with the addition of carbon monoxide and carbon dioxide in Phase II for source identification. In this Phase I Small Business Innovation Research project, formaldehyde and nitrogen dioxide will be detected in the mid infrared by laser absorption spectroscopy in a fiberoptic system. Simultaneous control of two lasers will be developed, and the performance of the fiberoptic system will be optimized, with a mind towards the design of the Phase II prototype. These objectives will be achieved through tasks including: spectroscopy; development of the fiberoptic system; and design of laser control software. This research will directly benefit the public, including city residents and people living in high-traffic corridors and dense neighborhoods, by providing a new tool to better understand pollutants and toxics in cities. This sensor will further environmental justice goals by identifying hotspots of pollutants urban areas. Additional benefits to the public include improved understanding of indoor air quality. This could lead to better regulations of formaldehyde, typically present in concentrations indoors that are much higher than outdoors, and of nitrogen dioxide, carbon monoxide and carbon dioxide, which are emitted from indoor combustion sources including cooking. The proposed instrument is of great interest to current Urban Integrated Field Study scientists looking at air quality disparities in cities.