Sunscreen May Impact Tiny Ocean Denizens: Hydrogen Peroxide Harms Phytoplankton

It turns out that sunscreen could be hurting our environment. Scientists have found that when certain sunblock ingredients wash off our skin and into the sea, they can become toxic to some of the ocean's tiniest denizens, which are the basis of the food chain for many other marine animals.

The main problems lie in titanium dioxide and zinc oxide nanoparticles. These are common ingredients in sunblock, and can react with ultraviolet light from the sun and form new compounds, such as hydrogen peroxide. High amounts of hydrogen peroxide can harm phytoplankton, which are the microscopic algae that feed everything from small fish to shrimp to whales.

In order to see whether sunblock could be impacting local beaches and water, the researchers examined the waters of Majorca Island's Palmira beach on the Mediterranean. They also included tourism data in order to find out exactly how much sunscreen was potentially being introduced.

So what did the scientists find? It turns out that titanium dioxide from sunblock was largely to blame for a dramatic summertime spike in hydrogen peroxide levels in coastal waters.

The findings reveal that these chemicals are indeed being introduced into near-shore waters. That said, more research needs to be conducted in order to find out if or how hydrogen peroxide may be impacting phytoplankton and other small organisms. This could be especially important considering how many tourists flock to Mediterranean beaches each year. In fact, it's estimated that 200 million tourists enjoy the beaches each year.

As sunscreen use continues to rise, it's important to assess exactly what chemicals are involved in creating these sun-blocking lotions. If there are compounds that are affecting the environment, it's crucial to phase out these compounds in order to keep our oceans a bit healthier.

The findings are published in the journal Environmental Science & Technology.