According to a research report on drinking water and air quality in urban areas published on March 1 on forbes.com, Philadelphia, Bakersfield and Fresno are the most toxic cities in the United States.

Philadelphia is the most toxic city in the United States images 1

To complete the list, forbes.com looked at the 80 largest metropolitan areas in the United States and checked the number of " Superfund " sites , abandoned areas containing toxic substances, as well as indicators. Air quality (AQI) and toxic waste (TRI) index.

The report shows that Philadelphia metropolitan areas have a total of more than 50 " Superfund " locations. California cities have very poor air quality.

In 2009, Bakersfield city had 43 days, the AQI index exceeded 100 on a 500 scale. Fresno had 29 days, while Los Angeles had 14 days and the AQI index exceeded 100.

According to forbes.com , the city of Philadelphia has the poorest broth of the surveyed cities, followed by Fresno and New York City.

The EWG, an environmental non-profit group in Washington DC, said users should use water filters to avoid any contaminants in tap water.