America's dirtiest cities: Washington/Baltimore ranks #16

If you ever have trouble breathing or find the air a little stale in the Washington and Baltimore area, you're not alone, Forbes reports.

But, look at this way: it could be much, much worse.

A Forbes study says that the D.C./Baltimore/Northern Virginia area ranks as America's 16th dirtiest region.

PHOTOS: See the Forbes Top 20 list here.

The area, which encompasses nearly 8.5 million people, has an ozone pollution rank of 14.

Among other factors, the ranking took into account the metro area's population, its ozone pollution level and the number of days when the air is deemed unfit to breathe.

Several of the top cities are in areas that either have horrendous automobile traffic or are in heavy manufacturing or coal towns.

Check out the full list here.