Principle Investigator: Jesse H. Kroll

Year Awarded: 2018

Institution: Massachusetts Institute of Technology

Volatile organic compounds (VOCs), carbon-containing gaseous molecules that arise from a wide range of sources – personal care products, materials, indoor activities such as cooking or smoking, and even people themselves – represent a key class of indoor air pollutant. VOCs are important not only because some of them can be harmful to health, but also because they can react in the air to form other hazardous pollutants, such as ozone and fine particles. However, current approaches for measuring VOCs have major limitations: they either involve sampling air over long periods of time, providing relatively low time resolution (one measurement per day), or they require expensive, research-grade equipment that cannot be routinely used in many locations over extended periods of time.

This project involves developing a new approach towards the measurement of indoor VOCs, the use of real-time monitors that are relatively low in cost (no more than a few thousand dollars each), enabling their widespread use. Such monitors will be made up of an array of low-cost techniques (metal oxide semiconductors, electrochemical cells, and photoionization detectors) for measuring airborne organic species. Because these are highly non-specific, responding to many VOCs in different ways, any one sensor cannot by itself characterize or quantify complex VOC mixtures. However the signals from many such sensors, each with its own characteristic response toward different VOC types, can provide information on the overall chemical makeup of VOC mixtures. This project will involve several steps:

  • the design and construction of the multi-sensor VOC monitor;
  • the study of how the monitor responds to different VOCs, by exposing it to different VOC mixtures and calibrating/training it using advanced analysis techniques (such as machine learning algorithms)
  • the improvement and re-design of the monitor based on these results; and
  • the use of several of these monitors to measure the VOC composition of different indoor environments.

The objective of this project is provide a new tool for the measurement of VOCs in the indoor environment, ultimately improving our understanding of the links between human activities, the composition of indoor air, and human health and well-being.