By: CBS News Baby food from several of the country's largest manufacturers are "tainted" with toxic heavy metals, according to a disturbing new government report. The report, released Thursday morning, says those baby foods have "significant levels" of substances including lead, arsenic, cadmium and mercury. The metals can be especially dangerous to babies' and toddlers' brain development. Parents often say they are looking for the healthiest, safest food for their babies. But as Connecticut mom Carrie Kerner found out, it's difficult to look for something you may not even be aware of. "I just looked for the ingredients," Kerner told CBS News consumer investigative correspondent Anna Werner. "If there was any added preservatives, sweeteners or added sugars, I wouldn't buy it, so I basically just wanted to get organic."