Rampe says that it is possible to detect the fingerprint of Rocky flats plutonium in places throughout Boulder County. The Colorado Department of Public Health and Environment explained the dangers of plutonium in the air in the Rocky Flats Public Exposure Study. It said radiation emitted by plutonium cannot penetrate skin, but that a tiny particle breathed, ingested or taken into the body through a wound may result in cancer, harm the immune system or cause other damage. As breathing is the most common pathway for plutonium into the body, the lung is the organ primarily affected. The particles lodge in the soft tissue of the lung or enter the gastrointestinal tract and bone marrow through the blood stream.
Smaller particles are more likely to be inhaled, and less likely to be expelled by the body.
They were also less likely to be trapped in filters the DOE used to use to clean contaminated smoke released into the air when the site was still producing nuclear weapons. Harvey Nichols is an advocate for nuclear responsibility and a professor of biology at the University of Colorado at Boulder. In 1974 he was asked by the DOE to study samples of fresh snow in the buffer zone. He was surprised by the findings, which indicated very high levels of plutonium particulates in the snow. Nichols said it was later discovered that chimneys at the facility were filtering only large particles, and not the smaller, most dangerous ones.