Good morning all,
As we remain on-schedule, we will not meet in-person for lecture on Friday (15 Nov). I'd like instead to offer you several pieces of recent science news:
We have considered issues surrounding vaping several times this terms, most recently the alarming and poorly-understood severe respiratory distress that has developed in otherwise healthy individuals who vape. After several months of investigation, our CDC (Centers for Disease Control and Prevention) have released a report that appears to identify the likely cause of his distress syndrome: vitamin E acetate, and oily compound used as a additive in some vaping products.
Vitamin E and its derivatives are lipophilic (fat soluble), which allows them to interact with cell membranes more easily than most biological compounds (which are hydrophilic, or lipophobic). Multiple samples of lung tissue from persons afflicted with vaping-associated respiratory distress have revealed this compound adhering to the lung surface. If you remember our discussions on lung structure/function, we described the exchange surface between the alveoli and the capillaries of the lungs as being as thin as possible (essentially, two single-cell layers of epithelium), to allow as much gas diffusion across them as possible. Now, imagine that same surface covered with a sticky, oily residue - it's easy to see that gas exchange could be severely impaired.
There may be other substances contributing to this distress syndrome, and not all experts are convinced that vitamin E acetate is the culprit. But, the evidence is accumulating, and it appears likely to be the primary cause of the cases investigated so far.
If you do vape, check your products - do they list this as an additive? Can you select other materials that do not?
Juul, one of the largest companies producing vaping products, recently agreed to stop making some kinds of flavored vaping products, as they and others in the industry were being accused of improper marketing toward minors:
One young person with vaping-associated respiratory distress recently was forced to undergo a double lung transplant:
Vaping seems like a habit to be avoided at all costs, in my view. Our lung tissue is simply not designed to handle contact with things other than atmospheric gases. In a few years, we may look back at this as a trend that appeared, and briefly flourished, before its significant health implications were well-understood. I suspect that regulations around vaping will get tighter and tighter, and the available evidence suggests that our public health would be best served by limiting access to vaping materials and more carefully regulating their contents.
Have a great rest of the week - see you on Monday for Chapter 22 (DNA Biology and Technology).