Photonics Reaps What Farm Denizens Sow

Richard Gaughan

Lasers in factories, fiber bundles in operating rooms, even cameras sitting on computer monitors are common sights. Now, based on work being done at the University of North Carolina, optical systems could be found next to every silo or manure pile.
A decade ago Lori Todd, associate professor of environmental sciences and engineering, recognized the need to accurately map the distribution of pollutants in industrial environments. In a leap over single-point sampling methods, she combined a field-deployable Fourier transform infrared system from Midac Corp. of Costa Mesa, Calif., with computer tomography developed for medical imaging. The result was a system that can map airborne toxic distributions on the factory floor in near real time, helping to identify and correct hazardous conditions.
Now she's applying that technology (for which she earned a National Science Foundation presidential faculty fellowship in 1994) to a different class of pollutants: agricultural emissions.
As population spreads into once-rural areas, public concern -- for reasons of health and comfort -- about agricultural pollution also has spread. Todd's sponsor, the state of North Carolina, hopes her chemical mapping system eventually might be useful for identifying agricultural hazards and odors. This requires a move from the relatively benign environments of the laboratory or factory floor into, literally, the field.
Todd is currently experimenting at animal waste lagoons to optimize the placement of system components and to quantify the effects of airflow. This testing will validate her system against current air sampling methods.
But for now, if you want to find agricultural pollutants, you'll just have to follow your nose.