New study on fertilizer/animal waste pollution

[_Doc]

A new study says that farming is the worst at producing air pollution. It says "that when ammonia from fertilizers and animal waste combines with nitrogen oxides and sulfates from exhaust pollution, microscopic solid particles, so-called aerosols, are created. Aerosols can reach deep into the lungs, causing heart or pulmonary disease. It's estimated fine particulate air pollution is responsible for more than 3 million death each year around the world."

I feel like they pulled the number of deaths out of a hat. But, I maybe wrong.

Here is the link to the article
http://www.voanews.com/content/farm-pol ... 32351.html

And here is the research letter
http://onlinelibrary.wiley.com/doi/10.1 ... 68354/full

[brimstoneSalad]

"It's estimated fine particulate air pollution is responsible for more than 3 million death each year around the world."

From that single source?

"A new study says that farming is the worst at producing air pollution."

Worst among an arbitrary number of differentiated sources, or creates the majority of that kind of air pollution?