"about 75 percent of the population chose health and safety concerns" though this summary doesn't spell out "GMO being safe to eat" vs. "concerns about more pesticide use".
Opposition anti-correlates with knowledge of genetics: the more you know, the less concerned about GMO safety you are. And in the US (but not Europe), the ignorant considered themselves knowledgeable.
Opposition isn't a left-right thing.
See the DW comments at https://mindstalk.dreamwidth.org/512224.html#comments