Hi,
For faster response please post on the Experts forums and not this Interview forum.
1) Are microwaves a concern for human health if they negatively affect plant growth?
microwaves can be a concern, this is why microwave ovens have interlocks that turn the oven off when the door opens.
http://www.arpansa.gov.au/radiationprot ... nonion.cfm
2) As an expert, what do you think of microwaves and how they might negatively affect health or growth?
One need to know how much exposure is in question: even solar light can be harmful with long exposure.
3) In a microwaved oven, why do the microwaves only majorly affect water molecules?
Please search "how do microwaves work" there are many good answers out there.
It has to do with the frequency of the waves, In principle one could build a microwave that preferentially heats oils but no one would buy one
cheers,