I personally am skeptical of the idea that sunscreens are actually responsible for marine ecosystem changes, rather than climate change or other large forces. The majority of a chemical sunscreen formula is inert base. And we’re talking about thin films of sunscreen diluting into a vast body of water. Further, most people at the beach are using water resistant sunscreen, further reducing the potential for harm.
Sunscreens are really valuable technology. They prevent skin cancers and sun damage, and I think policy should err on the side of encouraging their use.
I further think that reactive, feel-good measures like banning straws and demonizing sunscreen do much more harm than good, because they cause fatigue and apathy about environmental issues and do little to solve them.
I would've said so, too, before my GF got into the reef tank hobby. Corals are ridiculously sensitive to pretty much everything. Light, chemicals, nutrients, water flow, diurnal rhythms, you name it. It's fairly believable that something in the low parts per billion might affect them adversely, particularly organisms that are already stressed.
But is there anything functionally wrong with zinc oxide sunscreen? If not, why is it not available as the default option with chemical sunscreens available for those who want to go out of their way to not look pale?
Anyway, if you spend a lot of time in the sun or at the beach the functional problem with zinc oxide is pretty clear: it's harder to spread and put on. This might not seem like an issue but if you spend a lot of time dealing with it, the annoyance adds up.
tl;dr: exposure to sunlight without sunscreen has benefits for cardiovascular health - and the kinds of cancer you get from direct exposure to sunlight on a regular basis (basal cell and squamous cell carcinomas) are almost never fatal. The benefits to CV health significantly outweigh the increased risk of these carcinomas.
Melanomas only account for 1-3% of skin cancers and are less likely in outdoor workers and tanned people than they are in indoor workers.
> “The risk factor for melanoma appears to be intermittent sunshine and sunburn, especially when you’re young,” says Weller. “But there’s evidence that long-term sun exposure associates with less melanoma.”
Makes sense, humans probably wouldn't have made it this far without going outside.
[1] https://www.outsideonline.com/health/wellness/sunscreen-sun-...
https://onlinelibrary.wiley.com/doi/10.1111/joim.12251
It reduces blood pressure.
Folks out here worried about how wrinkly their skin might look at 75 when nobody cares instead of cardiovascular health though :)
Anyone in the 2 and 3 range can build significant sun tolerance by being careful, 4 and 5s don't generally need sunscreen. Jury is out on skin cancer, Bantu people in Africa don't all die of melanoma, so clearly melanin is doing a lot of work here.
That's not to recommend that you try doing that yourself, just a weird fact I learned. its hard to calibrate sun exposure. But theoretically starting from very sensitive skin isn't a barrier.
If you go to Asia where most women avoid any sun exposure at all (up to wearing masks and gloves) you’ll note there skin looks amazing even into their 50’s.
And the few minutes of exposure you get each day is usually enough to provide vitamin D. I think it’s like 12 min of upper body exposure in moderately intense sunlight is enough.
https://pubs.rsc.org/en/content/articlelanding/2002/pp/b2012...
Vitamin D production is highly dependent on time of day and latitude. At latitudes closer to the poles, even extended sun exposure might not stimulate much vitamin D. You can find online calculators which show this for your location.
I mean, it's pretty clear that sun exposure damages the skin. And it's not just skin cancer but other pre-cancerous changes and just premature aging.
https://www.msdmanuals.com/home/skin-disorders/sunlight-and-...
That article isn't strictly wrong to say that exposure to sunlight is linked with melanoma, but it's linked to childhood sunburns and intermittent sunshine/sunburn. Sunburns are bad, sun is good.
> And perplexingly, outdoor workers have half the melanoma rate of indoor workers. Tanned people have lower rates in general.
I think it's also fair to say that exposure to the sun doesn't cause premature aging so much as not being exposed to the sun makes you look younger than you would otherwise - but of course that only helps if you're alive. Direct sun exposure reduces all-cause mortality. [1]
Which is not surprising considering the need for sun exposure for things like vitamin D.
But I'm not sure mortality is the best measure? Maybe quality of life? Getting surgery to remove a basal cell carcinoma and having failed skin grafts (happened to my grandmother) seems like a heavy burden to cost of life not captured in mortality.
I kind of resent the idea that this is model to strive for. Ok, you look somewhat better, but you also pay price of constantly limiting activities and having to be careful what you do ... all the time.
There was an interesting paper that show a woman who applied a sun protecting lotion to her face everyday for the last 30 years of her life.
But she didn’t apply it to her neck. The difference is very stark at 70 years old. The skin on her face was wrinkled but her neck look absolutely worse in terms of age and skin damage.
But I think people really underestimate the impact of sun damage, particular if your skin is quite pale.
This is considered a virtue among traditional Asian women.
It's important to consider of course that different races age differently. Is it masks and gloves, or is it being of the local ethnicity? Not getting any sun at all is really bad, after all, since as the article shows, vitamin D supplementation is quite ineffective.
The political will to solve problems is a finite resource. Squandering it on trivial crusades is, IMO, one of the most wasteful and harmful decisions that could be made.
Trivial to some upper class person in an air conditioned home who doesn’t want to think about bad things and who’ll survive no matter what is certainly not trivial to billions increasingly struggling to survive with no way to escape to greener pastures.
https://www.researchgate.net/publication/325157337_Social_cl...
Yes, if you are trying to change human beliefs and attitudes, you can't disregard human nature or behavioral psychology. Duh.
Gee, humanity had better act fast to protect that precious finite resource. What would our children and grandchildren think if we squandered our political will to solve problems?
https://www.hawaii-guide.com/blog/hawaii-new-reef-safe-sunsc...
Many of the dive boats and hotels will offer sunscreen out of a bulk pump, so depending on what you do on the islands, you probably don't need much on your own - just a small tube for your group will do.
Point is, the regulations to keep those ingredients out of the reefs have been mostly successful.
Also a lot of people on Maui actually live there and aren't even tourists.
https://www.theatlantic.com/technology/archive/2022/07/us-su...
Previous discussion on HN: https://news.ycombinator.com/item?id=31954294
There are also reef-safe sunscreens that rub in much more clear.
This means: Put a largish drop on a fingertip and rub it in, then repeat, and repeat, and repeat. If you squeeze out enough that you need to keep it in the hand instead of on a finger, it's going to show.
I love it a lot. Zinc Oxide is great for being a true "sunblock" (rather than merely "sunscreen") of broad-spectrum UV (instead of just UVA or just UVB/UVC). Also doesn't interact with endocrine system like many of the chemical sunscreens.
https://www.dermstore.com/eltamd-uv-clear-broad-spectrum-spf...
"How come they aren't getting sunburned?" I wondered.
"They're using chemical sunscreens," was my wife's answer.
And that's often right next to a signpost telling people how those chemicals are killing corals.
This is why we can't have nice things.