Answer:
Studies have been conducted on synthetic products, including DDT and estrogen. The use of these synthetic products has been discontinued due to increased risk of cancer and other health concerns. Genetic engineering has increasingly been used in cattle, crops, and pharmaceuticals.
Explanation:
I'd think it's probably the recycling of newspapers, as trees are making of paper can be a reason for deforestation. With recycling of newspapers, fewer trees need to be cut down.
It's controversial because the best source of stem cells is a human embryo (an aborted fetus).
), etc.