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Guest: Dr. Robert Reynolds; Topics: Cardiovascular issues with Apollo lunar astronauts, mortality statistical studies, human spaceflight studies, confounders, and more. Please direct all comments and questions regarding specific Space Show programs & guest(s) to the Space Show blog which is part of archived program on our website, www.thespaceshow.com. Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See www.onegiantleapfoundation.org/amazon.htm.
We welcomed Dr. Robert Reynolds to the program to discuss his important research paper, "Mortality due to Cardiovascular Disease Among Apollo Lunar Astronauts." The paper was published by The Aerospace Medical Journal and can for a short time be downloaded free of charge from The Space Show blog for this show. You can also download the paper here: http://docserver.ingentaconnect.com/deliver/connect/asma/23756314/v88n5/s10.pdf?expires=1513463200&id=0000&titleid=72010555&checksum=396734A13BA580C24A861E18E9432E8F. I strongly recommend you read the paper prior to listening to this interview. The interview was a two segment 90 minute discussion with email questions from the listeners.
I started the discussion by asking our guest how and why he got interested in this subject, plus I inquired about the nature of mortality research in general. Dr. Reynolds talked about mortality research methodology and the Proportional Mortality Ratio. You do not want to miss what he said about this as understanding the field was crucial to understanding the analysis and conclusions from his research project. Other issues were discussed in the first segment which were variables. These included age, gender and race diversity (there was none with the Apollo lunar astronauts), plus we talked about what was known as the healthy worker effect. Don't miss what he said about that important aspect of this type of research. Furthermore, in this segment we touched up cause of death or causality. He said normally the death certificate signed by a doctor generally does a good job of capturing the cause of death for an individual. This was important so be sure to listen to how cause of death is used in this type of research.
We spent a good portion of the first segment focusing on astronaut cardiovascular disease. One of the problems faced in doing this research was the lack of research studies. That condition exacerbates the already existing small group problem. Dr. Reynolds frequently referenced some of the research papers that seemed to play a more important role in his study than others. These specific research papers included the 1993 paper listed as Reference #8 among his references. In addition, he talked about the Michael Delp paper several times. See #5 on his list of references for his paper. Our guest also cited the work by Dr. Frank Cucinotta regarding his radiation studies. Recall that Dr. Cucinotta has been a guest on TSS two times regarding his studies and research.
Other questions and topics for the first segment included differences and variations with Soviet/Russian cosmonaut data and US astronaut data but keep in mind cosmonauts were not on the Moon. Later, listener Linda asked about iron in the lunar regolith. Don't miss what our guest said about that. It was followed up later in the discussion by a listener as well as myself pointing out that there was iron ore in the Southern California beach sand and we were wondering if there were studies about the impact of that iron on people exposed to it by being on the Southern California beaches. This brought up the subject of terrestrial studies that often have very large sample sizes, sometimes thousands of people in the sample as compared to space studies which have just a few people in the studies. The small sample size or small group causes problems in really understanding the area being studied. This is a complicating factor for space mortality and statistical studies.
In the second segment, we talked about the need for space flight participant follow up be they government astronauts or civilian space tourists. Robert suggested that the requirement to participate in follow up studies should be part of their spaceflight contract. The spaceflight sample size needs to grow to be more valuable so it would be imperative to follow up even the space tourists.
During this segment, we talked about living on the Moon, radiation and microgravity exposures and how one might have to modify mortality research for a lunar settlement, artificial gravity and new variables added to the mix. He said NASA was very good at doing this and was confident the research studies would evolve alongside our spaceflight capabilities. At one point I asked if it were possible to do spaceflight primate research, would that be a good option. Don't miss what he said about my suggestion.
Carl asked about the need for people to honestly disclose pre-existing conditions because if they went to space and say had had cancer before, if they get it again or worse, it would skew the research. Our guest had much to say about the need to disclose pre-existing conditions prior to taking a spaceflight. The subject of children in space came up, research studies with children in space, a space pregnancy and fetal development in the space environment. Again, don't miss what our guest had to say on these subjects.
Robert described another concept in the attempt to quantify uncertainty, the "central tendency." Listen to what he said about this and such analysis. Next, we talked at some length about variations which can be a significant issue. This led to again talking about causality, the two main factors with it, and then the concept of confounders.
Listner Barbara asked our guest about his table showing NASA Astronaut Corps as compared to Air Force Programs. He said additional studies will piggyback on these earlier studies but again noted the small sample size. I asked him if it might be possible to increase the sample size by advanced robotic or AI mortality studies. Don't miss what he said about that. Before the program ended, Randy asked about the variation in diet, especially between the Russian diet and the American astronaut diet. He thought diet might be a factor in cardiovascular disease given diet is a factor in that disease here on Earth. Don't miss what he said about diet variation. We concluded the discussion with his final remarks plus his upcoming work that we will find interesting and report on here on The Space Show.
Please post your comments/questions on TSS blog for this program. You can reach Dr. Reynolds though the Mortality Research website, http://www.mortalityresearch.com.