Mexico City has long dumped its waste water in the valley, and the contaminated water is then used by regional farmers to irrigate crops. Once in the edible foods, heavy metals such as lead and nickel can make their way to consumers, where they can contribute to neurological and other health problems.
“The organic toxins we can take care of pretty easily with a number of different methods, but the only way to really get rid of those heavy metals is to treat them with filtering agents like activated charcoal (like what’s found in a Brita filter), but those types of materials are kind of expensive,” says Schauer. “They are a little expensive for us to use, but they are very expensive to the people living in that region.”
After testing various samples of plants from cacti to flowers, the researchers determined that cilantro is the most prevalent and powerful so-called bioabsorbant material in the area. Bioabsorption is the scientific term for using organic materials often found in plants, that when dried, could replace the charcoal currently used in filters.