Since 1997
by Neal W. Pollock, Ph.D. on April 10th, 2017

In a recent DAN article about exercise and diving, I read the following:

Intense physical activity — generally with substantial muscular forces and joint loading (the application of forces on joints) — is believed to transiently increase micronuclei activity, the
presumed agent of bubble formation.

Are these micronuclei preexisting? Where do micronuclei come from, and how are they formed or created?


by Frances Smith, EMT-P, DMT on April 10th, 2017

​I recently returned home from a two-week liveaboard dive trip. After experiencing some initial motion sickness while adapting to the motion of the boat, I had a wonderful trip. At the end of the trip, however, I felt like the dock was rocking when we disembarked. I was queasy and almost vomited. This feeling continued for nearly a week before resolving. Why did this happen?


by Scott Smith, EMT-P, DMT on April 10th, 2017

​Why does it seem like the answers I read in Alert Diver are so conservative? You advise caution for medical issues I would never give a second thought to when participating in other activities such as skiing, tennis, basketball or exercising at the gym. It seems like your organization is afraid for anyone but the healthiest people to dive.


by Neal W. Pollock, Ph.D. on April 10th, 2017

​I know nitrogen is not metabolized by the body, and I've read that tech divers are facing issues with helium bends. Is the size of the molecules relevant? Helium molecules are smaller and lighter than oxygen molecules, while nitrogen molecules are larger. Some people are filling their car tires with nitrogen because it supposedly leaks out of the tire more slowly than air.


by Frances Smith, EMT-P, DMT on April 10th, 2017

​I am 79 years old and healthy. I have not been diving in several years and would like to get back into it. Are there any recommendations, prohibitions or limitations for a diver my age?