The health impacts of pollution are hard to track. Changes in pollution can take years to show up as changes in health. California is known for its environmental regulations. Now, data are demonstrating the effectiveness of the actions.
“California saw a significant drop in seven major toxic air pollutants between 1990 and 2012. All told, this cleaner air has led to a 76% decrease in Californian’s associated risk of developing cancer due to exposure to seven major air pollutants.” – Scientific American
The health improvements have happened even while total miles driven, population, and the economy have grown.
(Click on the graph for the link.)