My limited research indicates that the body activates a complex strategy to repair DNA damage to skin cells which experienced UV exposure. This repair strategy takes between 24 hours and 48 hours to complete. Therefore, repeat exposure to sunlight for boosting Vitamin D should be controlled so that repair of DNA damage will always be at least marginally faster than the rate at which damage occurs. When excessive DNA damage occurs, either in one large dose or a moderate dose one day and another moderate dose the next day and the next, the repair strategy lags and skin cancer will appear, especially in the weeks after one EXCESSIVE dose or probably after frequent moderate doses. The trick is trying to find the right dose and frequency of sunshine exposure depending on skin type.
Thank you so much Richard for this amazing and informative post!!
I totally agree, they should really examine this more closely and start giving people answers.
Have they ever conducted a study with a real person to get the 150min time span for fair skin individuals or has it just been calculated? It sounds like it's just been calculated and that's why there are doubts about the actual action of repair mechanisms. Can you confirm that?
It would be very interesting because maybe at low UVIs, as you wrote, there might not be any long term damage to the skin.
I think of this as a wall made of clay, when it's hit hard by something (high UVIs), it gets damaged quickly and it takes time to get repaired, which means it keeps getting damaged deeper and deeper and when it's built back up you can see the signs of the damage that occurred and it might be easier to break in the future, on the other hand, when it's hit softly (very low UVIs) the wall is not damaged at all, or just very lightly and is repaired straight away without leaving any long term damage even after a prolonged time (maybe not even erythema after a lot of hours). For medium UVIs (e.g. 3-6), the wall gets deeply damaged eventually because it keeps getting hit hard enough and the repairing is not as quick, in this case you might end up with the same damage as the high UVIs scenario if you stay in the sun long enough.
This is how I visualise it and I hope it makes sense.
Thanks Richard, I forgot to say in my video that the rate of heat loss through radiation is proportional to the 4th power of the temperature in degrees Kelvin. The same argument applies to the loss of heat radiated from air above the ground into space.
Richard, after one of my comments about deforestation being much worse for global warming than combustion of fossil fuels. you asked me to post a link to my source of information. This latest lecture on my video channel adds more scientific information to my previous lecture series on this subject.
If you can find time to listen and critique or correct my explanation in this lecture, I will appreciate that. Or forward my request to another NIWA scientist who might do that for me. hearing from them
My limited research indicates that the body activates a complex strategy to repair DNA damage to skin cells which experienced UV exposure. This repair strategy takes between 24 hours and 48 hours to complete. Therefore, repeat exposure to sunlight for boosting Vitamin D should be controlled so that repair of DNA damage will always be at least marginally faster than the rate at which damage occurs. When excessive DNA damage occurs, either in one large dose or a moderate dose one day and another moderate dose the next day and the next, the repair strategy lags and skin cancer will appear, especially in the weeks after one EXCESSIVE dose or probably after frequent moderate doses. The trick is trying to find the right dose and frequency of sunshine exposure depending on skin type.
Thanks Michael.
Thank you so much Richard for this amazing and informative post!!
I totally agree, they should really examine this more closely and start giving people answers.
Have they ever conducted a study with a real person to get the 150min time span for fair skin individuals or has it just been calculated? It sounds like it's just been calculated and that's why there are doubts about the actual action of repair mechanisms. Can you confirm that?
It would be very interesting because maybe at low UVIs, as you wrote, there might not be any long term damage to the skin.
I think of this as a wall made of clay, when it's hit hard by something (high UVIs), it gets damaged quickly and it takes time to get repaired, which means it keeps getting damaged deeper and deeper and when it's built back up you can see the signs of the damage that occurred and it might be easier to break in the future, on the other hand, when it's hit softly (very low UVIs) the wall is not damaged at all, or just very lightly and is repaired straight away without leaving any long term damage even after a prolonged time (maybe not even erythema after a lot of hours). For medium UVIs (e.g. 3-6), the wall gets deeply damaged eventually because it keeps getting hit hard enough and the repairing is not as quick, in this case you might end up with the same damage as the high UVIs scenario if you stay in the sun long enough.
This is how I visualise it and I hope it makes sense.
Fabio
Sorry, it seems I'd need to log onto something to see this one.
Richard, I sent the wrong link by mistake. Here is my lecture about biological processes.
https://www.brighteon.com/dashboard/videos/dfc382f0-8998-42f0-ac91-5544ec7a5449
Richard, this complementary lecture explains the correlation between atmospheric Carbon Dioxide and mean global surface temperatures in terms of biological processes. https://www.brighteon.com/f3ff49da-da85-49ee-a2c1-a4c8aded9e3b
Thanks Richard, I forgot to say in my video that the rate of heat loss through radiation is proportional to the 4th power of the temperature in degrees Kelvin. The same argument applies to the loss of heat radiated from air above the ground into space.
Richard, after one of my comments about deforestation being much worse for global warming than combustion of fossil fuels. you asked me to post a link to my source of information. This latest lecture on my video channel adds more scientific information to my previous lecture series on this subject.
https://www.brighteon.com/f3ff49da-da85-49ee-a2c1-a4c8aded9e3b
If you can find time to listen and critique or correct my explanation in this lecture, I will appreciate that. Or forward my request to another NIWA scientist who might do that for me. hearing from them
Thanks Michael. I’ll take a look.