Why does the EPA worry so much about pollution from factories and automobiles?

Money and political power.

Errr, that's its reason for being. That is what it was set up to do.

As for volcanoes...mmmm why not tax them, and imprison them if they don't pay up? Hey why not put bans on hurricanes? Threaten to execute them if they disobey? Or how about setting up vigilante groups to capture tornadoes?

So your question is not exactly well thought out, and your facts are wrong also. YES actually a good sized eruption will emit more pollutants than all human activity. The only problem is the time scale, 1 eruption [average20 ? a year] = amount of human created pollution emitted each and every second!

The EPA already does have many regulations in place to limit various polluting agents from factories, such as for sulfates, nitrates, carbon monoxide, and so on. Many are discussed here:

http://en.wikipedia.org/wiki/National_Emissions_St...

and many others that are subject to export notification requirements (not necessarily air pollutants) can be found listed by their CAS numbers and such here:

http://www.epa.gov/opptintr/import-export/pubs/12(...

and the specifics of the TSCA here:

http://epw.senate.gov/tsca.pdf

And this is because all of these *can* be regulated, as opposed to volcanic eruptions. As to your claim that a volcano emits more pollution than all of the factories in the world combined (I would gladly contest that just on the basis of mass comparison), you have to better define what you even mean by pollution. Are you trying to pass off the lie that volcanoes emit more CO2 than humans do? Try the other way around, and try at least two orders of magnitude less.

First you are incorrect, second, factory processes and automobiles can be made to operate with fewer pollutants. Man can write regulations for volcanoes, but would not be able to enforce the regulations. Why don't you come up with a sensible question.

EPA is in charge of enforcing laws against pollution, not pandering to liars who flunked science.