Four zip codes in the WDBJ7 viewing area are ranked among the most toxic in Virginia, according to an Environmental Protection Agency report.

Covington was ranked the most toxic. Zip codes in Lynchburg, Montgomery County, and Narrows were all ranked in the top 15.

In 2012 alone, Covington residents were exposed to nearly 3,000,000 pounds of toxic air emissions -- some of which cause cancer, birth defects and brain disorders.

Those chemicals include:

• Acetaldehyde which has been linked to cancer, birth defects and neurological damage.

• Methanol which may contribute to birth defects and neurological damage.

The report cites MeadWestvaco, which has a paper mill in Covington, as the primary source of toxic air emissions in the city.

The 24141 area code includes Grede-Radford LLC. and the U.S. Army Radford Army Ammunition Plant.

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