It's the number one contaminant of groundwater, drinking water, rain water.

(c) Where the act is perpetrated using explosive or inflammable materials, or toxic, incendiary, contaminant, bacteriological, chemical or radioactive and other similar materials.

NASA initiated this research to control or prevent the buildup of medically harmful microorganisms in the air, water, and trace contaminant control systems of long duration on crewed spacecraft.

So, we thought the worst problem would be a single molecule contamination of the native chromosome, leading us to believe that we actually had created a synthetic cell, when it would have been just a contaminant.

Now what's interesting is, of course, that we're still using 80 million pounds of atrazine, the number one contaminant in drinking water, that does the opposite turns on aromatase, increases estrogen and promotes tumors in rats and is associated with tumors, breast cancer, in humans.