The industrialization and urbanization movements have resulted in air pollutants being commonplace in industrial and residential areas; pollutants are produced by automobiles, manufacturing processes, and home improvement, among other activities. Air toxics pose a significant risk to public health and lower quality of life due to both acute and chronic health impacts. Therefore, there is a need for transportable, autonomous air toxic monitors that can identify and quantify toxic chemicals. However, the current state-ofthe-art monitors are not suitable for neighborhood-level surveillance due to their relatively high cost, and/or their lack of automation. Therefore, a relatively low-cost, autonomous unit is needed to quantify and identify chemical pollutants in neighborhoods at levels that meet or exceed EPA thresholds. To address this gap, this effort will miniaturize a state-of-the-art benchtop terahertz (THz) spectroscopy unit to fit within a pelican case, creating a unit that can be produced at a moderate cost (~$10,000 per unit at scale), autonomous device. THz spectroscopy can identify highly volatile air toxics that have a dipole moment based on the unique, multi-component rotational spectra; these unique features enable identification and quantitation even in complex mixtures at the ppm, ppb, and in some cases ppt levels. No commercial units exist leveraging THz spectroscopy for gas-phase monitoring and detection despite its advantages in resolution over other optical-based spectroscopic techniques and in cost over mass-spectrometry based techniques. Advancement in MEMS technology and components now make miniaturization, automation, and ruggedization practical for a transportable, autonomous unit. Therefore, this effort will miniaturize, autonomize, and ruggedize the benchtop unit and create a spectral library of select air toxics.This effort will provide a key autonomous monitoring tool for the identification of key pollutants both in the residential and the occupational space, providing a critical tool to both identify sources of pollution as well as to enable mitigation strategies. The end product also has commercialization value; the VOC gas sensor market is expected to be worth $186 million (M) by 2025. Initial markets will involve those most afflicted by the release and presence of air toxics and odors for identification and testing, but also to confined space occupations, first responders, chemical firms, oil and gas industry, and the DOD. UESÂ’ technology will effectively fulfill the three requirements: 1) low-cost devices, 2) ease of use, and 3) ability to identify and quantify the air toxic.