Arsenic, long known as cancer-causing agent, is showing up in America's chicken meat – and it is not by accident.

According to an article in the April 9 issue of Chemical & Engineering News, the weekly news magazine of the American Chemical Society, the arsenic-based compound roxarsone is routinely added to the feed of 70 percent of the broiler chickens produced every year in the U.S.

Click here to read the full story.

While this additive to chicken feed is non-toxic in its natural form, it converts into inorganic arsenic within the bird.

The Environmental Protection Agency notes that chronic exposure to inorganic arsenic can cause cancer of the bladder, lungs, skin, kidney, nasal passages, liver, and prostate, as well as skin damage and circulatory problems.

The article notes the products from the breakdown of roxarsone end up in chicken meat. It is also excreted in chicken litter, contaminating land and groundwater.

And while the EPA has recently strengthened the standards for arsenic in drinking water from 50 parts per billion (ppb), the standards for arsenic residues in poultry have remained unchanged for decades.

One study found that 55 percent of chicken sampled had arsenic levels ranging from 1.6 to 21.2 ppb.

Arsenic additives are already banned in the European Union, and Tyson Foods, the U.S.'s largest poultry producer stopped using arsenic additives in 2004.

McDonald's has also jumped on the bandwagon, asking its suppliers not to use the additives.

In the case of roxarsone, the industry is moving ahead of regulators. According to Chemical & Engineering News, neither the Department of Agriculture nor the FDA has actually measured the level of arsenic in the poultry meat that people consume.