Sun, Sunscreen, + Coral Reefs

Where did Sunscreen come from?

We’ve been protecting ourselves from the sun for a while. Early civilizations utilized a lot of plant material to protect themselves. Greeks, for instance, used olive oil, and Egyptians sought out extracts from rice, jasmine, and Lupine plants.

The sunscreen that we know and love today isn’t even a century old! It wasn’t until the early 1930s that we had something that resembled our current sunscreen. This early creation was a sunburn cream developed by a South Australian chemist named H.A. Milton Blake. L’Oreal founder and chemist, Eugene Schueller, shifted this sunburn cream into a more official sunscreen formula later in the 1930s. However, these early products weren’t all that protective. They didn’t even have SPF (sun protecting factor)! It wasn’t until 1938 that we saw the first sunscreen created with SPF. This sunblock was created by Fran Greiter and had an SPF of only 2! Greiter was the one to develop the SPF rating system that we still use today. 

What is SPF?

SPF popped up because we needed a system to standardize all of these new products that were coming out. Without a system to rate their efficiency, we really wouldn’t have known if a given product worked as it should. SPF is a measure of the fraction of sunburn producing rays that reach our skin. So, if you have a sunscreen that has an SPF of 30, that means that 1/30th of the sunburn producing rays are going to reach your skin. Of course, this is on the assumption that the sunscreen was applied correctly. And did you know that the correct amount of sunscreen is 1 tablespoon per body part? That means 1 tablespoon for each arm, leg, one for your face, etc.!

The Food and Drug Administration (FDA) in the United States adopted the SPF calculation in 1978. Since then, sunscreen standards and labeling have continued to evolve. The FDA released a comprehensive guide to sunscreen in June of 2011. You can find that here. The guide was designed to help individuals figure out what the most suitable sunscreen was for their personal needs.

Modern Sunscreen

Our sunscreen market now is mostly made up of two different types of sunscreen: chemical/mineral and physical.

Chemical/mineral sunscreens use ingredients like oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate, which allow chemical sunscreens to work like a sponge would. The chemical sunscreens absorb the sun’s rays so that our skin doesn’t have to! Physical sunscreens work by deflecting the sun’s rays and contain ingredients like zinc oxide and titanium dioxide.

Sunscreen does a lot to protect us but there are still some downsides. In chemical sunscreens, two ingredients have caught a lot of flak – oxybenzone and octinoxate. Because people put on sunscreen and then go swimming, sometimes in the ocean, these chemicals have been able to seep into the water. The issue with these two specific ingredients comes down to coral reef damage.

Coral Reefs

Coral reefs only account for 1% of the ocean floor but they are home for more than a quarter of all marine species! This makes coral reefs one of the most biodiverse ecosystems. Coral reefs are important for more than their biodiversity, though. Coral reefs act as a massive tourist attraction so they also play a vital role in our global economy. Coral reefs provide food and resources to more than 500 million people in more than 100 countries due to their yearly economic value of $375 billion 

What are Coral Reefs?

Inside coral reefs, you’ll find polyps. Polyps are individual animals that form together to create our reefs! You’ll also find zooxanthellae, a symbiotic alga that lives inside the tissue of coral reefs. Zooxanthellae is also what gives the coral its color! Polyps and zooxanthellae have a mutually beneficial relationship. The coral helps to provide carbon dioxide and waste products that the zooxanthellae can utilize during photosynthesis. The process of photosynthesis for the algae helps to nourish the coral by providing oxygen and organic products. The coral use these compounds to help create new calcium carbonate (which is limestone!). Calcium carbonate is what the coral reef skeletons are made of!

The relationship between zooxanthellae and the coral exists with really specific conditions. That’s partially why coral reefs aren’t found everywhere – the only waters that fit the bill will be in tropical or subtropical areas! The water needs to be both clear and shallow so that sunlight can reach the algae. This is essential for photosynthesis to take place. The water temperature also needs to stay in between 77 to 84 degrees Fahrenheit. 

Most of our coral reefs are in danger. The World Resource Institute released a report about coral reefs that showed 75% of the world’s coral reefs as at risk. Nearly a quarter of our coral reefs are already damaged beyond repair. Without a change in our behavior, it’s expected that 90% of our coral reefs will be in danger by 2030, with nearly all of them to follow suit in 2050. Many of the reefs that we see today have 40-50% less coral than they did only 30 years ago!

Coral reef bleaching image from The Independent

What role does Sunscreen play?

We deposit sunscreen in the water! This happens by getting in the ocean to swim but it can also happen by showering after being on the beach or at the pool and by using aerosol sunscreen applicators! About 14,000 tons of sunscreen are thought to wash into the ocean each year. As mentioned, the ingredients that create the most concern are oxybenzone and octisalate. These ingredients contain nanoparticles that can disrupt coral’s production and growth cycles, which can lead to bleaching. According to Dr. Craig Downs, an expert on the impacts of sunscreen on marine life, oxybenzone has toxic impacts even at really small concentrations. The sort of small concentrations he’s talking about would be equivalent to one drop of sunscreen in an Olympic size swimming pool! 

Places like Hawaii, one of the most popular coral reef destinations, are taking steps to mitigate coral reef damage done by sunscreen. This is taking place through bans on the sale of sunscreens that feature these harmful ingredients. However, sunscreen isn’t the only thing damaging coral reefs. Pollution, the littered plastics that overwhelm our ocean, and climate change also pose threats to our reefs. Finding a good sunscreen is one way to help alleviate the stress the reefs face but doing our part to limit waste and pollution will allow us to go the extra mile.

It’s possible to find coral reef safe sunscreen, though! The market for sunscreen is quite large so finding something that fits your skincare needs while also keeping in mind the coral reefs is a breeze. In the past five years, worldwide searches for “reef safe sunscreens” have quadrupled on Google! For information and recommendations on reef-safe sunscreen, go here. To learn more about coral reefs and how to protect them, check out The Reef Restoration Foundation.