Everyone should use sunscreen when out in the sunshine.

But if you spot a scientist at the beach applying a layer of algae to their skin, don’t be alarmed.

A paper, recently reported in ACS Applied Material & Interfaces, explains that scientists are analyzing the natural sun-blocking properties of algae and fish slime to create a shield against the Sun for people, textiles and outdoor materials.

Tempting though it is to top up a tan or relax comfortably in the Sun’s warming beams, the Sun continually pumps out harmful ultraviolet rays. And don't be fooled into thinking that the clouds will protect you, as they don't block all of them. 

Ultraviolet (UV) radiation, in the forms of longwave ultraviolet A (UVA) and shortwave ultraviolet B (UVB) destroy Vitamin A in the skin, which can cause a greater risk of skin cancer, premature aging, wrinkling, and loss of elasticity in the skin.

There are two types of sun-blocking sunscreens: ones that absorb UV rays, and ones that act as a physical barrier. A variety of natural and synthetic substances can perform these roles, but unfortunately, many of those that are commercially available often aren't effective over a long period of time or are environmentally unfriendly.

Searching for an all-natural solution, Professor Vincent Bulone and his research team, based at the University of Adelaide in Adelaide, South Australia, turned to molecules found in algae. These microbes produce natural sun-blocking molecules to protect themselves from harm: mycosporine-like amino acids. And since the organisms get gobbled up by fish, these molecules accumulate in their bodies and secretions.

“Mycosporines are present a little bit everywhere, in many types of organisms," says Professor Vincent Bulone, coauthor of the research paper, speaking to The Lead South Australia. "We have attached these small UV absorbing molecules in a non-reversible manner to a polymer called chitosan, that you can extract from the shells of shrimp or crabs.”

Chitosan is an all-natural UVA and UVB blocking polymer with many applications. Because of its high stability and versatility, chitosan can be used in sunblock creams, coated on fabric materials, or even applied to outdoor furniture.

Though extracting the algae-derived molecules is an expensive process, Bulone believes that productions could be done by engineering bacteria. He added: “This has been [possible] since the early 90s. It's not a cheap process, but it can be done.”

While regulators in the United States are hesitant to approve of sunscreen components used in other countries, Bulone reckons that introducing these products into the mass market may be relatively simple as they are already in use in beauty products and medicines.

[H/T: American Chemical Society]