9) Los Angeles for its Air pollution
Public health experts agree the greatest risks for developing serious lung diseases occur in places that have bad air, and California has more cities with bad air than any other state in America. Los Angeles and its surrounding areas again top the list as the worst place in America for air pollution. Other California cities that are also in the top 10 worst places for air quality are Hanford, Fresno and Modesto. The reason these California locations are so dangerous for your health is a combination of natural and artificial factors: they are located in valleys, which act as a trap for the bad air, and there are a lot of particulates released into the environment, due to the burning of fossil fuels and pesticide spraying. Local weather reports in the summer regularly warn residents of dangerous levels of air pollution, to the point where people are advised to avoid going outside.