Search This Blog

Tuesday, June 18, 2013

Patricia's A Bad Health Physicist & Scientist

Well she claims she's a health physicist and scientist.  She posted a comment on Conca's blog (the post I mentioned earlier):


"I am not a creationist. I am, in fact a scientist. I have an undergraduate degree in Health Physics, certified in the comprehensive practice of Health Physics by the American Board of Health Physics; I have a Master’s degree in Health Physics and a PhD in Epidemiology. I have been working in the field for approximately 35 years. I have worked in many aspects of health physics; from medical health physics to reactor health physics. I have worked on numerous “low dose” studies looking for the “smoking gun.” I have spent considerable time working for international organizations on post-Chernobyl health effects research. I understand the difference between a scientific theory and a scientific hypothesis. Let me explain them to you.

A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of knowledge that has been repeatedly confirmed through observation and experiment. Scientists create scientific theories from hypotheses that have been corroborated through the scientific method, and then gather evidence to test their accuracy. As with all forms of scientific knowledge, scientific theories are inductive in nature and do not make apodictic propositions; instead, they aim for predictive and explanatory force. The strength of a scientific theory is related to the diversity of phenomena it can explain, which is measured by its ability to make falsifiable predictions with respect to those phenomena. Theories are improved as more evidence is gathered, so that accuracy in prediction improves over time. Scientific theories are the most reliable, rigorous, and comprehensive form of scientific knowledge. This is significantly different from the way the word “theory” is used in the everyday lexicon.

A hypothesis, on the other hand, is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous observations that cannot satisfactorily be explained with the currently available scientific theories. A scientific hypothesis is a proposed explanation of a phenomenon which still has to be rigorously tested. A hypothesis can be disproven, but cannot be proven to be true.

In the case of LNT, there are thousands of studies that point to the fact that doses less than 10 rem (100 mSv) are not problematic for human health. In 1981 the GAO examined the thousands of studies of low dose radiation (at that time about 80,000+ credible scientific studies) and concluded at that time that “there is no way yet to determine precisely the cancer risks of low-level ionizing radiation exposure and it is unlikely this question will be resolved soon.” GAO 1981 “Problems in Assessing the Cancer Risks of Low level Ionizing Radiation Exposure” It is now 2013, thousands more studies have been undertaken; more and more research on cells and radiation exposure has been conducted; hundreds of epidemiologic studies have been published and yet there remains no proof of LNT (the “T” by the way stands for threshold, not theory).

Unfortunately no amount of study can prove LNT to be true- the doses are simply too small, there are too many confounding factors and there simply aren’t enough people on the planet to test it. It is an un-testable premise. In human cells, both normal metabolic activities and environmental factors can result in damage to the DNA with as many as 1 million individual molecular lesions per cell per day. How do you separate out the damage done from normal metabolic processes, environmental insults (i.e. chemicals), normal background radiation, sunlight, medical applications of radiation and radiation from an event such as Fukushima? Thousands of researchers and hundreds of millions of dollars over the past 100 plus years have yet to yield anything except a hypothesis which requires more study. LNT has, however, provided a good living for a lot of people. (myself included)

Maybe there simply isn’t an effect. Or, maybe, just maybe, the impacts of radiation have been a driver in evolution. After all, the world has been a very radioactive place. Simply back-calculate the current natural activity levels several million years ago and you have very radioactive environment. Life has evolved in a radioactive world."

She seems intelligent enough, so I believe her credentials (though she is employing the fallacy of argument from authority).

But how can someone with those credentials not understand the difference between a hypothesis and theory?

I responded:

I’m a CHP Emeritus, and you are largely correct and partly incorrect. A hypothesis is a small scale idea, which must be capable of being tested for it to have validity.

But notice what you also said, “Unfortunately no amount of study can prove LNT to be true.”

You also wrote, “A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of knowledge that has been repeatedly confirmed through observation and experiment.”

A scientific theory can not be proven true (just what you said about LNT!), it can only be supported over time by the preponderance of the evidence (LNT can be traced back to Hugo de Vries, (not in its current state of course), so it’s older than the theory of relativity).

One good source of a well-substantiated explanation of low dose radiation health effects (LNT) is the National Academy of Sciences BEIR VII report.

Note that LNT, like evolutionary biology and Big Bang cosmology (all three well-substantiated explanations) can be proven FALSE if the appropriate evidence is discovered. In the case of LNT, the DOE spent over a decade and over $100,000,000 trying to find that evidence in their Low Dose Radiation Research project and they failed. That absence of evidence provides even greater confidence in LNT.

If you have the evidence, then publish it and shift the scientific consensus. At least understand that to usurp the consensus by going around the scientific method and proposing your own “science” is unethical. If you have evidence to shift the consensus, publish it and earn respect. No one won a Nobel Prize by blogging or commenting in blogs."

Unfortunately I had a dentist appointment scheduled and didn't have time to write more.


No comments:

Post a Comment