Even though lung cancer is one of the most prevalent forms of cancer in the U.S. today - caused in part by poor air quality and pollution - a new report indicates that the atmosphere is considerably cleaner than it once was.

According to its "State of the Air 2013" report, the American Lung Association reports that smog and ozone pollution is far less prevalent in the U.S. among many metropolitan regions of the country. For example, in 18 cities, air quality was vastly improved in this most recent study when compared to last year when measuring overall particle pollution. There was so much improvement in these areas, in fact, that nearly 90 percent of them saw their lowest recorded levels of particle pollution.

Harold Wimmer, ALA national president and CEO, indicated that this is definitely good news for homeowners and speaks to the environmental awareness that many people have.

"We are happy to report that the state of our air is much cleaner today than when we started the 'State of the Air' report 14 years ago," said Wimmer. "Even in parts of the country that experienced increases in unhealthy days of high ozone and short-term particle pollution, they still have better air quality compared to a decade ago."

Millions of Americans living in substandard air conditions

At the same time, though, there are still indications that air quality in the country could be much better than it is. The report points out that roughly 132 million people - 42 percent of the U.S. population - reside in cities where the particle pollution ratio is too high. In addition, 25 million Americans live in counties where multiple measures of air quality are compromised.

"The work is not done," said Wimmer. "The Environmental Protection Agency must continue the work necessary to achieve the promise of the Clean Air Act - healthy air that is safe for all to breathe."

Experts with the ALA made a variety of recommendations that it encourages the EPA to adopt. For example, before 2013 comes to a close, it encouraged the government to establish more rigorous gasoline vehicle emissions standards. By limiting the amount of sulfur dioxide that emanate from cars and trucks, more than 2,500 lives may be spared due to premature deaths caused by immunodeficient illnesses.

They also advise establishing more robust carbon pollution guidelines for power plants that burn coal for fuel. The pollutants that coal puts into the air - such as mercury, benzene, arsenic and lead - have been shown to contribute to cancer and various other cardiovascular diseases. Putting a larger focus on clean coal can help minimize this health risk.

Common symptoms of air quality issues

While these are all large-scale ways in which to improve air quality, homeowners can be adversely impacted by the air they breathe in their very own homes. Whether it's due to mold buildup or heating sources that provide warmth to a residence, people's health complications may be exacerbated if they live in a place where pollutants reside. An air quality test performed by a home inspection company can help homeowners determine what's lurking in their homes and how it can be removed.

There are usually several indications that suggest a house inspection may be in order. According to the International Association of Certified Home Inspectors, tell-tale signs include the presence of mild and mildew, stale air that never seems to go away inside a residence, little to no air movement, excessive humidity indoors even when conditions are dry outside and foul odors that are unusual or unfamiliar.