Your last comment is about what I told Dee this mornin'.......(talkin' about the subject of the link you provided)...I was discussing that and commented that the "urban" dwellers are generally exposed to the opposite...i.e. - Toxins,poisons....particularly in the areas like the refineries in the Houston Ship Channel area and East of Houston....as well as others near the Gulf.....and not to forget ....the pollutants connected to urbanization/city life
I'm currently re-reading "Adventures With A Texas Naturalist" by Roy Bedichek and am reminded, again,....how far our "industrial/chemical machines" ...have taken us away from that lifestyle that our grandparents & before....knew and experienced....relative to a more "natural" - unspoiled exposure to Texas' beautiful & interesting fauna/flora that slowly, but surely, is disappearing...... Yes,....I know it's worldwide,.....but since I grew up here....it means more to me. Just my 2 cents worth