A
Okay, uh, could you tell me what you think contributes most to, uh, air pollution?
B
Well, it's hard to say. I mean, while it's certainly the case that things like automobiles and factories, uh, pollute a lot, uh, if you look at how much pollution is say kicked up by an active volcano, uh, it's certainly less than clear that anything man can do in this sort of scale of things has much effect at all. What do you think?
A
Um, well, you talked about, uh, volcanos. I'm not sure how many active volcanos there are now, and, and what the amount of material that they do, uh, put into the atmosphere. I think probably the greatest cause is, uh, vehicles,
B
Uh-huh.
A
especially around cities. Um, uh, do you live right in the city itself?
B
No, I'm more out in the suburbs, but I certainly work near a city.