Most people similarly discard household toxins: they know throwing batteries/CFLs/paint/etc in the general-purpose dumpster is not "ok", but for them it's an easy & effective solution. Disastrous for someone/something somewhere sometime, but not for "me, now".
Silent Spring was published in 1962. It brought environmental problems to mainstream Americans. As a result of new awareness the EPA was created.
What seems "obvious" now might not have always been obvious.
Lets not forget there have been over 2,000 (known) nuclear weapons test in the world. 1032 done by the US alone, most in Nevada. It is well known that these tests released massive amounts of radiation that affects human health. Clouds carried the radiation across the United States into the Mid-West and Northeast and deposited it with rain.[1][2][3][4]
[1] http://jama.jamanetwork.com/article.aspx?articleid=390963
[2] http://www.sciencemag.org/content/220/4592/18.abstract?sid=e...
[3] http://www.ieer.org/latest/iodnart.html
[4] http://www.americanscientist.org/issues/pub/fallout-from-nuc...
> While this is worrying, some scientists argue that most of the containers will in all likelihood remain sealed for decades to come...
"Thus solving the problem once and for all." "But--" "ONCE AND FOR ALL."
Made up numerical example, if you have a lake where the bacteria can literally eat one barrel of crude per month, and 10 barrels at the bottom of the lake, you're in pretty good shape if one breaks open at a time spread over a century, but fairly well screwed if all 10 rust open at the same time at the six month mark.
Hell, sounds like most kick-the-can-down-the-road politicians we have today, regarding a whole slew of issues. It's nice to see how far we've come in 70 years. 8-P