Tech to thwart food poisoning, bioterror

Scientists hope to use a new mathematical technique to detect red tides, or toxic algae in the ocean, before infected shellfish can make people green.

Researchers from Carnegie Mellon University are working with various government offices to develop a "spatiotemporal" data mining system for finding and tracking toxic algae blighting North American waters. The toxins not only kill marine life, but also cause many people to get ill upon eating tainted shellfish.

Doing the manual work for researchers, the system can mine through thousands of satellite images from NASA and oceanographic data from the National Oceanic and Atmospheric Administration (NOAA) to detect where red tide is affecting human and sea life.

"Spatiotemporal data mining extracts changing spatial patterns from continuous data flow," said Yang Cai, a computer scientist at CMU's CyLab, a research program for technology and policy issues.

Spatiotemporal data mining is a fast-growing field that could have implications for numerous areas of research. On a basic level, the system is designed to analyze the location of one object over time to predict the future. For example, if scientists were to analyze the historical data from the Global Positioning System in a person's car over months, they could likely predict when that person will go food or clothes shopping next by drawing from local information and his or her buying patterns.

That same method could help track known murderers. Or it could be adapted to help detect acts of bioterrorism in the nation's waterways, Cai said. Satellite imagery from NASA can make visible the chlorophyll concentration in bodies of water, and because bioterrorism can affect those levels, an attack would be apparent.

The system for red tides looks at NASA images over eight years and historical oceanographic data over 50 years that show the chlorophyll and algae concentration of the sea floor. Cai said that his team has also translated scientific knowledge into the data-mining algorithms, a new technique on an otherwise statistics-based system.

CMU is working with NASA's Earth-Sun System Technology Office, the Goddard Space Flight Center and the NOAA, which are funding the research.

Red tide includes a microscopic algae known as Karenia brevis, which naturally form in the Gulf of Mexico and release toxins deadly to fish and marine mammals. It can also be debilitating to people who've eaten shellfish containing the toxin. According to NOAA, more than $20 million was spent on public health care for people suffering food poisoning from shellfish in the late 1980s and early '90s.