(NaturalNews) Sunblock ingredients that wash off swimmers' skin and into the oceans form toxic chemicals that may be destructive to nearly all life in the oceans, according to a study conducted by researchers from the Mediterranean Institute for Advanced Studies in Spain and published in the journal Environmental Science & Technology.

Sunscreens have long been made with the ingredients titanium dioxide and zinc oxide, which effectively block ultraviolet radiation from reaching the skin. In recent decades, sunscreen manufacturers have largely turned to using these ingredients in nanoparticle form. At such a tiny scale, these particles, 100,000 times smaller than the width of a human hair, have fundamentally different physical and chemical properties from what they do at the normal, everyday scale that we're used to. This means that sunscreens made with nanoparticles are less oily and easier to rub into the skin, but their health and environmental properties are largely unknown.
Nanoparticles form chemical that poisons ocean life
Prior research has suggested that, in the presence of sunlight, titanium dioxide nanoparticles may react with water to form numerous potentially toxic chemicals, including hydrogen peroxide. High levels of hydrogen peroxide are known to be particularly lethal to microscopic algae known as phytoplankton, which form the base of the ocean's food web and are responsible for producing much of the Earth's oxygen.

In the new study, researchers wanted to determine whether titanium dioxide nanoparticles from sunscreen could be washing off swimmers' skin and increasing hydrogen peroxide levels in the ocean.

"Tourism is one of the world's largest industries, and coastal tourism is in many countries the fastest-growing area of contemporary tourism," researcher David Sanchez-Quiles said.

"Sun care products have increased an average of 7