U: One Test, Two Test, & Cancer Risk in Karnes County
Radiation placard at General Atomics dump outside Panna Maria. Scientific research suggests nearby residents have been dosed with similar radiation levels as nuclear industry workers.
By Greg Harmangharman@sacurrent.com
Doctor William Au phones me just as I’m pulling into Falls City. A soon-to-be former professor of environmental toxicology in UTMB’s Department of Preventive Medicine and Community Health, Au is busy boxing his things. He’s accepted a position as chairman of a department of preventative medicine at a medical school in China.
After nearly 20 years teaching at UTMB at Galveston
, and nine years as Director of the International Science Outreach Program, Au is moving on. And yet, even now, his contribution to our understanding of the public health impacts related to the South Texas uranium fields is little understood.
Au co-authored several important papers that showed how exposure to uranium mining and milling wastes has taken a toll on the health of families in Karnes County, site of several large radioactive dumps.
Generally, it’s been the state department of health that has garnered pacifying headlines for suggesting there is no increase in cancer risk in this area. Dr. Au just laughs when I mention the state statistical study.
“They were forced to do a study,” he tells me, “but the population is too small to do that kind of study … The result was predictable to be negative because [the population] is too small to do anything meaningful.”
By comparison, Au’s research has looked not at cancer statistics, as the state has, but at the actual cellular damage that can be observed. His research suggests, for instance, that residents around the waste pits near Panna Maria and Falls City have received the amount of radiation exposure one would expect to find among nuclear industry workers.
[I caught up with Au again this week.
You can listen in to our discussion by clicking play below.]
After weeding out smokers or those who had received X-rays over the past decade, the team settled on 24 residents living within 1.5 miles of several dump sites where increased radon gases and other toxics had been observed.
The paper, “Biomarker Monitoring of a Population Residing near Uranium Mining Activities” published in
the highly regarded Environmental Health Perspectives
in 1995 found that the DNA of Karnes County residents had more “chromosome aberrations” than a similar number of people not residing near toxic waste sites.
That data, though limited, “bordered on being statistically significant,” the report’s conclusion reads.
However, after exposing the resident’s cellular samples with another dose of radioactivity, researchers witnessed a “significantly higher frequency of cells with chromosome aberrations and deletion frequency than the reference group.”
This suggested residents’ DNA had been damaged, causing “abnormal DNA repair response” that would predispose the individual (or individual’s offspring) to future disease.
The conclusion states:
Although the mechanism for induction of such response is not known, we suggest that the abnormality may be caused by mutation of genes which code for DNA repair enzymes or by blockage of repair processes on DNA … These possibilities need to be investigated further using molecular assays.
Au returned to the problem this year with a report published in the International Journal of Hygiene and Environmental Health
. This time, he was able to utilize improved evaluation methods and show that residents near these waste sites “could have been exposed to a level of radiation that is similar to those for nuclear workers [and] … have increased risk for cancer over the non-exposed residents.”
I asked Au why more of this sort of work had not been conducted across the uranium fields of South Texas. Again, good-naturedly, he laughed, suggesting that getting funding for such work was not always easy.
Au was adamant that the state health department report was worthless. (He toned down a bit when I clicked record this week.) He said he challenged the researchers verbally and they're response was "Oh, yeah. We agree,” said Au.
Posted by gharman on 9/8/2009 5:20:57 PM
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