Researchers at Harvard University have used participants from a decades-old study of baby teeth to link those who lived near Coldwater Creek in north St. Louis County to increased instances of cancer.
Researcher Marc Weisskopf with the Harvard T.H. Chan School of Public Health led the study of participants born between the 1940s and the 1960s. Using their childhood addresses, he and his team found that those who had lived close to the contaminated waterway as children were more likely to report having been diagnosed with the disease.
“We found that participants living [less than or equal to] 1km had a higher risk of cancer compared to those more than 20 km, which perhaps points to creek-related radiation exposure as the likely culprit,” the authors of the study, published today in JAMA Network Open, wrote. “This may be because up to 5km away, individuals may still travel to the creek for recreational activities. But it could also suggest that radiation exposures probably extended beyond the creek’s floodplain.”
The researchers’ findings bolster what many residents have long argued and what other assessments from federal and state governments have suggested. But unlike those earlier reports, this study used participants’ childhood addresses to examine how exposure to the creek before remediation efforts began could be associated with health risks.
“That was the important question that hadn't been answered before,” Weisskopf said today on “St. Louis on the Air.” “We know where they were as a kid. We know where they are now, and we know what their cancer history was. So it was really a unique opportunity to get at sort of the key question.”
The study comes on the heels of a massive victory for those affected by radioactive waste in parts of the St. Louis region. Earlier this month, Congress voted to expand the Radioactive Exposure Compensation Act to include those in Missouri exposed to radioactive waste that stemmed from the region’s involvement in the Manhattan Project.
According to the U.S. Army Corps of Engineers, starting in the 1940s, radioactive waste generated by the St. Louis-based Mallinckrodt Company was stored in sites near what is now St. Louis-Lambert Airport. Over the years, that waste has leached into waterways, including dirt in the bed of Coldwater Creek, a 19-mile waterway that runs through St. Ann, Bridgeton, Florissant and other north St. Louis County communities.
The St. Louis Baby Tooth Survey began in the 1950s to assess whether children were being exposed to radiation from nuclear fallout due to weapons testing. Scientists had suggested baby teeth could absorb radioactive isotopes. By studying the teeth, researchers could gain insight into how populations were affected by nuclear activity, even if it was far away.
In 2001, 100,000 teeth from the survey were discovered in an abandoned building at Washington University. Researchers recognized the teeth had scientific value. Surveyors at Harvard have been attempting to identify the historic tooth donors and study how their health has developed over their lifetimes.
“The advantage of teeth is that once incorporated… they just stay there,” Weisskopf said. “It's like a little fossil record of what happened.”
The latest study does not study the teeth themselves. But Weisskopf said the repository contained helpful information: Those who donated the teeth included an index card with their home address — essentially geotagging where children lived in relation to the contaminated creek.
The study is one of several in which Weisskopf and his coworkers contacted baby tooth study participants later in life to study potential health effects of radiation.
Weisskopf said that it’s next to impossible to directly link a specific person’s cancer or other illness to a particular exposure event. Instead, studies like the one published today that look at population-level data can add up to create compelling evidence for residents who are looking for answers.
It can also provide evidence they deserve compensation through RECA and other programs.
“It certainly raises a very strong red flag and says it does look like what these community members have been saying for many years is, in fact, true,” he said. “The fact is, stuff was put in that creek that has led to many people to have cancers that they shouldn't have had…I hope it will help in some small way [to] the amount that it can validate this idea that compensation should be given.”
This story has been updated with comments from study author Marc Weisskopf.
