A Brief Summary of Research on Adverse Health Effects from the

Rocky Flats Nuclear Weapons Plant on Local Residents


In 1981, Dr. Carl Johnson, Director of Jefferson County Department of Health, used cancer diagnosis data for 1969-1971 from the National Cancer Institute’s Third National Cancer Survey to examine the relation between cancer rates and exposures to plutonium. Plutonium exposures were based on analysis of soil samples collected in 1970 from the region around Rocky Flats. The Johnson study found increases in many cancer types for persons in exposed areas, as compared with those for unexposed areas.  Cancers included lung cancer, leukemia, lymphoma, thyroid cancer, testicular and ovarian cancer, and brain cancer.  There were higher birth defects in Arvada from 1975-1977.

In 1987, Kenneth Crump, in a Department of Energy study, and others replicated the study design used by Carl Johnson and re-evaluated cancer diagnosis data for 1969-1971 and for 1979-1981. They confirmed Johnson’s findings, but could draw no conclusions about the association between plutonium concentrations in the soil and cancer rates after considering distance from the Denver metropolitan area.

In 1982, Dr. John Cobb and co-workers at the University of Colorado measured plutonium concentrations in autopsy samples from more than 500 persons who died in Colorado.  They compared those who lived near Rocky Flats with those who lived far from the plant, and found higher concentrations of plutonium in lung and liver tissue for people who lived near Rocky Flats. 

In 1990, researchers at the National Cancer Institute completed a study of cancer incidence and mortality around 62 nuclear facilities in the United States. This study showed slight elevations for some cancers in some age groups, but said data was hard to interpret because of limited information about other cancer-related factors.

In 1996, Dr. Richard Clapp of Boston University found a disproportionate rate of lung and bone cancers in areas around Rocky Flats, and “a continuing excess of cancer and ongoing health effects.”

In 1998, the Colorado Central Cancer Registry staff at the Colorado Department of Public Health and Environment found that cancer incidence rates for 10 selected regional statistical areas in the general vicinity of the Rocky Flats Plant from 1980-1989 were comparable to those for the rest of the Denver metropolitan area for the same period.

From 1989-1999, the State of Colorado’s Historical Public Exposures Studies on Rocky Flats attempted to identify the quantities of contaminants that were released off-site and to identify potential health risks to nearby communities from those contaminants.  Plutonium and carbon tetrachloride were found to be the most significant contaminates (between 1,100 and 5,400 tons of carbon tetrachloride were released), and other contaminants included beryllium, dioxin, uranium, and tritium.  The largest amounts of plutonium released from Rocky Flats into surrounding neighborhoods came from the 1957 fire and from more than 5,000 leaking barrels that had stood out in the open for more than a decade in the late 1960s.  Soil sampling showed that the highest off-site plutonium concentrations in soil were primarily east of the plant (subsequent studies have shown that plutonium concentrations have not decreased with time).  The study emphasized that people who lived near the plant and led “active, outdoor lifestyles” had the highest level of exposure to airborne plutonium.

 In 2011, independent testing was funded by local residents and the Rocky Flats Peace and Justice Center, and results were analyzed by Marco Kaltofen of Boston Chemical Data Corporation.  This study found plutonium at two locations near Rocky Flats, an outdoor sample along Indiana St. (directly across the street from the Rocky Flats property), and from beneath a crawl space under a house built in 1960 about a mile from the Rocky Flats site near Standley Lake.

A 1989 class-action lawsuit on behalf of nearly 13,000 local residents who believed their health and properties had been adversely affected by Rocky Flats took more than 20 years to wind its way through the courts.  In 2006 a jury decided in favor of the residents.  This was overturned on appeal by Rockwell and the Department of Energy, and in 2012 the Supreme Court declined to review the case (Cook v. Rockwell).

There has never been any health testing or medical monitoring for people who live around Rocky Flats.