Jane Wolfson sent me this article on some of the external damages caused by chemicals. A quote: "Economist Elise Gould has calculated that ...for the population that was six years old or younger in 2006, lead exposure will result in a total income loss of between $165 and $233 billion. The combined current levels of pesticides, mercury, and lead cause IQ losses amounting to around $120 billion annually—or about three percent of the annual budget of the U.S. government."
Ouch.