Agreed that it's small apples. I get a headache often when mowing the lawn, either from the noise or the fact that it's burning oil. (I also have 5 acres to mow with push mower) I say why not, as you are directly breathing in that exhaust fumes just a few feet away. With my retrofitted electric mower, I don't get headaches anymore and I don't have the noticeable oily film on my skin afterwards. I enjoy cutting the grass now!
Plus, I don't know about you guys, but my mowers only last at most 3 years, so an electric mower with a good battery pays for itself. Plus as a gas engine ages, they produce more and more emissions, burn oil, etc.
Here is an article about 1 hour of cutting grass is equal to 100 mile car ride.
http://www.infobarrel.com/Lawn_Mower...to_Change_That
I can't remember the thread but I have mentioned the 15 largest ship thing as well... pretty crazy huh.