Sandi -
La Leche League International has a number of good articles about bf and
contaminants.  There is an article by Betty Crase on pesticides and breast
milk at: http://www.lalecheleague.org/llleaderweb/LV/LVMayJun94p37.txt
You can also find an article entitled "Breastfeeding Remains Best Choice in a
Polluted World" at http://www.lalecheleague.org/Release/ReleasePollution.html
And finally there is a Greenpeace press release and the LLLI response at:
http://www.lalecheleague.org/Release/Earth97.html
http://www.lalecheleague.org/Release/EarthDay.html
I think these will help you.  Do you all know that the LLLI web site has a
lot of bf information?  Check it out at: http://www.lalecheleague.org/
Cynthia D. Payne
LLL of Berkshire County Mass