Studies are showing that Bt toxins found in Monsanto crops are harmful to mammalian blood by damaging red blood cells and more. Red blood cells are responsible for delivering oxygen to the body tissues through blood flow.
http://www.collective-evolution.com/2013/05/11/scientists-discover-bt-toxins-found-in-monsanto-crops-damage-red-blood-cells/#_
Toms Blog on Life and Livingness