If you're an American made sick by air pollution, pushing your state to clean up its act seems the logical response. However, this will only take you so far because half the early deaths caused by unclean air are the result of toxins that blew across state borders, according to new research, creating a co-ordination problem of the sort the world is generally bad at solving.

The cost of air pollution in human lives and damaged health is as eye-watering as living downwind of a power station. An estimated 3 million to 4.5 million people die each year as a result. On an economic basis alone, clean air legislation pays for itself many times over. Yet so much damage is tolerated because those who benefit the most are usually not the ones with a say in the matter.

The most obvious example is that children, who can't vote, are more affected by pollutants, particularly lead, in the air than adults, but MIT's Professor Steven Barrett has found another. Barrett tracked the major sources of pollution in America, and where the poisonous gasses and particulates do their damage, finding they are often far apart. In 2005 more than half the air pollution deaths in America had out-of-state causes, falling to 41 percent by 2018.

The worst long-range offender is sulfur dioxide released high into the atmosphere by coal-burning power stations, Barrett reports in Nature. In 2005 three-quarters of the reduced life expectancy was in a different state from the plant itself, leaving the representatives of the victims with little opportunity to force change. Until recently they couldn't have even known where the bad air was coming from.

A combination of coal's increasingly uneconomic status and Obama-era federal restrictions led to a 30 percent decrease air-pollution related deaths by 2018, Barrett finds. Encouraging as that is, it still means 66,000 early deaths that year. Some 4,000 New Yorkers are killed in 2011 alone by other states' pollution – more than died in the 9/11 terrorist strikes.

The whole thing is a smaller-scale version of the global problem where nations use the wind to dump their pollution on someone else, giving them little incentive to clean up.

"It's been known in Europe for over 30 years that power stations in England would create acid rain that would affect vegetation in Norway, but there's not been a systematic way to capture how that translates to human health effects," Barrett said in a statement. However, advances in computing allow the tracking of pollutants' movements in a way that was not possible until recently, and Barrett has taken advantage. Barrett added that ranges vary greatly by pollutant, with some falling mainly on neighboring states, while others end up in more unexpected places.