If this happens, larger animals which feed on the plankton could be affected

For humans, sunscreen is a saviour, protecting us from harmful UV rays which can cause cancer.

But the protective lotion could also be responsible for killing countless sea creatures, scientists have warned.

A new study claims that when certain sunscreen ingredients wash off skin and into the sea, they can become toxic to some of the ocean’s tiniest inhabitants - phytoplankton.

A new study claims that sunscreen ingredients such as titanium dioxide and zinc oxide react in the sunlight and form toxic compounds that wash off the skin into the sea. Compounds such as hydrogen peroxide can harm phytoplankton - tiny marine organisms. This chemical equation shows how titanium dioxide (TiO2) eventually produces hydrogen peroxide (H2O2) when it is exposed to solar radiation



Titanium dioxide and zinc oxide nanoparticles, which are common sunscreen ingredients, react with ultraviolet light from the sun and form new compounds, such as hydrogen peroxide.

High amounts of hydrogen peroxide can harm phytoplankton - the microscopic algae that feed everything from small fish to shrimp to whales.

The research was conducted by scientists from the Universities of the Balearic Islands and Río San Pedro, in Spain.



To investigate the impact that beachgoers could be having on the environment, they went to Majorca’s Palmira beach on the Mediterranean.

There, they were among about 10,000 beachgoers - a small portion of the more than 200 million tourists that flock to Mediterranean shores every year.

Based on lab tests, seawater sampling and tourism data, the researchers concluded that titanium dioxide from sunscreen was largely responsible for a dramatic summertime spike in hydrogen peroxide levels in coastal waters - with potentially dangerous consequences for aquatic life.

If plankton are killed, the impact could be huge, because they are the main food source for larger marine animals, according to the study, which was published in the ACS journal Environmental Science & Technology.

Antonio Tovar-Sanchez and David Sánchez-Quiles agree that sunscreen is the best way to protect skin from the sun’s rays if staying inside is not an option.

But they say that when sunbathers venture into the sea to cool off, some of their sunscreen washes off into the water.

High amounts of hydrogen peroxide can harm phytoplankton - the microscopic algae that feed everything from small fish to shrimp to whales. A SEM image of two types of phytoplankton is pictured