Los Angeles ranks first in the U.S. with the worst air quality, a report released by the American Lung Associations says. Los Angeles also violates the federal health standards for ozone an average of 122 days a year. The city has topped the "dirty air" list in 14 of the 15 annual State of the Air reports released so far.

Data collected between 2010 and 2012  found 22 of the 25 large cities in the U.S. registered high levels of ozone or smog.  Los Angeles, Houston, Washington-Baltimore and New York City are part of the list, The Guardian reported.

The report shows that ozone pollution in the country is on constant rise but particle pollution has shown a slight decline. Government efforts toward cleaner fuels and power plants has brought particle pollution to record lows in some areas, however warmer weather was causing more ozone pollution. 

Apart from Los Angeles, California's Central Valley also has bad air quality. 

"Air pollution is not just a nuisance or the haze we see on the horizon; it's literally putting our health in danger," said Bonnie Holmes-Gen, senior policy director of the American Lung Assosiation in California, according to The Los Angeles Times. "We've come a long way, but the status quo is not acceptable," he added.

The association assessed the metropolitan areas in the report on the basis of their recorded levels of ozone and main pollution ingredients in smog.

Ingham County received an "a" for particle pollution. This means that the air was pretty clean there. But, the reigion received "d" for ozone pollution. Clinton County received an "f" for ozone pollution. It means that it can affect people with lung diseases and children. 

"This is about people's basic health, and about a level playing field," said Gov. Jack Markell/ (D) Delaware, according to wilx.com.