Close Mo Farah reflects on his success ahead of his move to marathon running A white sea urchin embryo that was exposed to nontoxic levels of nano-zinc oxide. The green dye shows that other toxins are retained when exposed to nanomaterials. Advertisement © 2017 HNGN, All rights reserved. Do not reproduce without permission. Advertisement 0 COMMENTS CLOSE COMMENT Get HNGN's Top Stories Newsletter Everyweek You have already subscribed. Thank you.