EDITOR,

When formulating a dose risk assessment, how much damage a radionuclide can do is only part of the equation. Equally important aspects are how much contamination would pose a significant risk, and the likelihood of that level of contamination being reached.

Marion Fulk either knows, or should know, this. The fact that he did not include this in his Jan. 9 commentary, “Uranium a big threat to Tracy” leads the reader to wonder just what his agenda is. Clearly, it is not public education.

Fulk states that depleted uranium “poses a serious health threat, especially if inhaled in finely divided particles like those created by open-air explosives testing.” No mention is made of the likelihood of these particles remaining suspended long enough inhaled by Tracy residents, or anyone else for that matter.

He correctly labels uranium-238 an alpha emitter and describes the damage it can do “if lodged in the body.” However, Fulk fails to mention that since alpha radiation can’t penetrate the body’s outer layer of dead corneous cells, it can only cause damage from inside the body.

Fulk cites the “nearly fourfold” increase, from 2.5 person-rem per year to 9.8 person-rem per year, but neglects to inform the reader as to whether either of these levels is significant relative to normal background exposure. By comparison, the population dose from cosmic radiation alone is 213,000 person-rem, and the total dose from all natural background sources (i.e. cosmic, terrestrial, food consumption and radon) is more than 2 million person-rem.

If it “pains” Fulk “when lab employees seek to understate the very real health risks that stem from inhalation of radioactive and toxic materials,” why does he not find it equally disturbing when a former lab employee overstates the risk of inhalation of those materials

Steve Hall, Tracy