Here’s an interesting thing, via the Washington Post: Harvard and UC-Davis professors affiliated with the National Bureau for Economic Research found that rates of violent crime were higher in various Chicago neighborhoods on days when wind patterns blew car exhaust from major interstates in their direction. Here’s how the study itself puts it:

We identify the causal effect of pollution on criminal activity by comparing crime on opposite sides of major interstates on days when the wind blows orthogonally the direction of the interstate and find that violent crime is 2.2 percent higher on the downwind side. Consistent with evidence from psychology on the relationship between pollution and aggression, the effect is unique to violent crimes – we find no effect of pollution on the commission of property crime.

Freeways divide many residential areas in Chicago, as you can see here:

That irritating environmental conditions would lead to an increase in aggression is a premise that seems to make sense on an intuitive level, at least, while many studies have found an association between violence and unusually high temperatures.