https://www.washingtonpost.com/news/tripping/wp/2018/03/27/congestion-pricing-clears-the-lungs-too-researchers-say/ https://www.washingtonpost.com/news/tripping

https://www.washingtonpost.com/news/tripping/wp/2018/03/27/congestion-pricing-clears-the-lungs-too-researchers-say/ https://www.washingtonpost.com/news/tripping/wp/2018/03/27/c... >Researchers at Johns Hopkins University and other institutions who studied Stockholm’s congestion-pricing scheme found that the policy cut air pollution in the city center and reduced childhood asthma cases by nearly 50 percent.