FigTree Header 10.14



Review all 2022 Benefit videos

To advertise in print or online
Click here



Share this article
Search The Fig Tree's stories of people who make a difference:

Particle research aids clean-up of mine wastes

Growing from area concerns about nuclear waste on the Spokane Reservation and at Hanford, a Massachusetts researcher recently described how identifying the structure of radioactive particles can determine if the radiation is from natural background, old nuclear testing fallout or nuclear production.

Marco Kaltofen
Marco Kaltofen's research at the Worchester Polytechnic Institute offers insights on identifying radiation.

Marco Kaltofen, who did the study with the Worcester Polytechnic Institute in Massachusetts, told a Spokane gathering of the SHAWL Society in Wellpinit and Hanford Challenge of Seattle that the distinction gives scientific backing that promotes clean-up efforts, which are often hindered by claims contamination is just background radiation.

Identifying the source of radioactive contamination is the first step needed to hold the government accountable for what is actually in the environment, he said. 

Marco has conducted environmental sampling at the Hanford Nuclear Reservation near Richland, at Los Alamos, in the Gulf of Mexico and at the Midnite and Sherwood Mines and millsites on the Spokane reservation.

In work with the Boston Chemical Data Corporation to document sources and hazards of chemical waste exposures, Marco locates, collects, analyzes and testifies on physical evidence related to waste.

For his master’s degree research at Worcester Polytechnic Institute in 2009, he sampled radiological and mixed waste contaminants at Hanford and did microanalysis of radiation in particulate matter.

Marco tested the environment around Hanford—the fish, soil, water, air and workers’ homes.  He found uranium, plutonium and thorium at elevated levels, but was told that it was background radiation.

Frustrated as an engineer to “do quality measuring and be told it was no big deal,” he decided to find how to distinguish natural background radiation from other particles.

He investigated the form radon takes and how it gets into homes and moves in the environment.

“Radioactive dust contains a signature of compounds that indicates its source,” Marco said. 

He found particles, called “montasite,” in thorium at the Midnite Mine and found it in the tank farm and air at Hanford—connecting the chemical makeup of particles at the two sites.

Testing inert, safe samples, he found two to four radioactive particles in half an ounce of dust.  He isolated the hot uranium, plutonium or thorium dust particles. Under an electron microscope, he could see if the particles were melted from a nuclear detonation, crystallized as in natural background radiation or processed in weapons manufacture.

Another step was to look at the health effects of natural radiation and of global fallout from small potent particles.  While exposure to five picocuries of radioactivity in a billion particles is considered acceptable, he said, if a single particle breathed in lodged in the lungs it could cause damage.

“Near the Midnite Mine, overall radiation might not be much different than background, but presence of one very radioactive tiny particle can create health damage,” said Marco.

He tested homes around the uranium mines and Hanford, and collected data for two years, creating a methodology other scientists could repeat to quantify health risks in a way that would lead to regulating dusts and cleanup, because dusts are stirred in the cleanup process.

“Uranium miners can be eligible for health care if they can fingerprint the specific source of contamination as being from fallout, natural, processing or montasite,” he said.

Marco’s research provides the science to show cause and effect, but even with that evidence it’s hard for the U.S. government, which underwrote nuclear development, to take responsibility.  The nuclear industry does not allow anecdotal evidence, which much previous evidence was considered to be. 

For information, call 508-651-1661, email or visit

Copyright © March 2011 - The Fig Tree