Rocky Flats Truth & Transparency: Asking the CDPHE to Be Clear About What Its Cancer Studies Can—and Cannot—Tell Us

For years, people who lived near Rocky Flats have asked a difficult but important question: Did living near Rocky Flats affect the health of the people who were there?

The CDPHE has conducted cancer-registry analyses involving communities around Rocky Flats. Those studies are an important part of the public record. But there is an important distinction between the question many Downwinders are asking and the question those studies are actually capable of answering.

That distinction is the reason Rocky Flats Downwinders is launching the Rocky Flats Truth & Transparency Campaign.

Our request is straightforward:

Say what was studied. Say what was not. Study the people who were actually there.

The question of where people lived matters

Cancer registries are valuable tools for studying cancer in populations. But cancer-registry analyses generally classify people geographically based on where they lived when they were diagnosed. For Rocky Flats, that creates an important limitation. Someone may have grown up in Arvada, Westminster, Broomfield or another community near Rocky Flats during the plant's operating years, moved away decades ago, and later developed cancer somewhere else.

That person's cancer may be associated in the registry with the place where they lived at diagnosis—not with the community where they lived during the historically relevant period.

The reverse can happen as well. Someone who moved into the area years later and was subsequently diagnosed with cancer may be counted among cancers occurring in the current population near Rocky Flats even though that person was not there during plant operations.

That does not make the cancer registry wrong.

It means the registry is answering a different question.

The campaign's methodological review identifies this along with other important limitations involving latency, broad geographic study areas, small numbers and statistical power, cancer and age groupings, and the ecological design of the analyses.

What the studies can tell us

The existing analyses can help describe cancers diagnosed among people classified as residents of particular geographic areas during particular periods. That is useful public-health surveillance. But without complete residential histories, follow-up of former residents, exposure-informed geography, individual exposure information, and cancer-specific latency periods, those analyses cannot tell us the cancer incidence among everyone who lived in potentially affected communities during historically relevant periods. That distinction should be clear whenever the findings are presented to the public.

What we are not saying

Methodological limitations are not proof that Rocky Flats caused cancer.

They do not establish that a cancer cluster exists.

They do not prove that any individual's illness was caused by exposure from Rocky Flats.

And they do not make cancer-registry surveillance useless.

They tell us something much more specific: The conclusions we draw from a study should not go beyond what that study was designed and able to measure.

A finding that does not reach statistical significance is not the same thing as proving that no risk existed—particularly when the study cannot reconstruct where people lived during relevant historical periods or follow those people after they moved.

What Rocky Flats Downwinders is asking Colorado to do

We are asking the Colorado Department of Public Health and Environment and state leaders to take four concrete steps:

1. Clearly disclose the limitations of the existing Rocky Flats cancer studies whenever their findings are presented to the public.

2. Make the underlying information easier to examine, including study populations, geographic boundaries, cancer sites, age groups, time periods, observed and expected cases, incidence ratios, confidence intervals and data-suppression rules.

3. Convene an independent public technical review involving environmental epidemiologists, spatial analysts, affected-community representatives and experts who were not responsible for defending the conclusions of the earlier studies.

4. Develop a path toward research designed around the historical-exposure question—including residential history, migration, cancer-specific latency and exposure-informed geography.

   
   

These requests do not require the State of Colorado to prejudge what a better study would find. They require something simpler: Be precise about what we know, be equally precise about what we do not know, and help develop research capable of addressing the questions that remain.

Why this matters to Downwinders

Rocky Flats operated beside growing Colorado communities for decades. Many people who lived, worked or attended school in those communities are no longer there. Some have contacted Rocky Flats Downwinders after cancer diagnoses or other health experiences. Others are trying to understand the health histories of parents, siblings, classmates and neighbors. Their experiences are important, but individual stories are not epidemiological proof. That is precisely why better research matters. The community should not have to choose between accepting conclusions that extend beyond what existing studies can establish and making claims that science has not established either.

Rocky Flats Downwinders is asking residents, former residents, family members, healthcare professionals, researchers, community organizations and elected officials to support the Rocky Flats Truth & Transparency Campaign.

Our goal is not a predetermined scientific conclusion. Our goal is an answer worthy of the question.

Say what was studied. Say what was not. Study the people who were actually there.