Air Pollution and Crop Production

In the agricultural world one of the things that we think makes it wholesome is clean country air.  We all want less regulation and sometimes are the concerns about clean air can seem silly.  What if air pollution is causing my crops to have lower yields?  Prairie Farmer has posted this link about the effects of ozone on soybean yields.  The approach suggesting the article is to use genetics to overcome the pollution.  While agriculture may contribute a small share of the excess ozone, it comes from many sources and atmospheric conditions.