When slapping on factor 50 sunscreen to avoid the harmful impacts of UV exposure, environmental consequences might well be far from our mind. But there is a substantial (and growing) body of evidence showing the toxic impact the large number of synthetic UV filters commonly contained within off-the-shelf sunscreen can have on the marine environment once washed from our bodies.

The European Chemicals Agency has expressed concern about eight commonly-used sunscreen filters, including titanium dioxide and zinc oxide, both toxic to marine phytoplankton upon exposure to low levels of UV light. The Environmental Effects Assessment Panel (EEAP), part of the United Nations Environment Programme, concurs with this position.

‘There are significant concerns that conventional sun protection products are having a negative impact on the environment,’ outlines Antony Young, a professor at St John’s Institute of Dermatology at King’s College London. ‘Our data shows that, with further research and development, marine-derived sunscreens may be a possible solution that could have a significant positive impact on the health of our marine habitats and wildlife, while still providing the essential sun protection that human skin requires to guard against damage that causes diseases such as skin cancer.’

Such ‘marine-derived’ sunscreens have been the centre of attention for a number of years, especially since the Australian Institute of Marine Science and the Commonwealth Scientific and Industrial Research Organisation suggested that natural filters mimicking the way corals protect themselves from high UV levels could potentially be harnessed as a natural filter for human skin. New research from Young and PhD student Karl Lawrence at KCL suggests that the chemical ‘palythine’, a mycosporine-like amino acid (MAA) derived from the edible seaweed chondrus yendoi (pictured above), could play a central role in creating sunscreen that doesn’t harm the natural environment.

‘MAAs are found in almost all marine species that are exposed to UV radiation,’ explains Lawrence. ‘We specifically used palythine for three reasons. Firstly, it is one of the most abundant MAAs found in nature. Secondly, there were reports that it has some anti-oxidant activity. Finally, we had a fairly pure source of palythine from chondrus yendoi. This species produces high amounts of palythine and negligible levels of other MAAs – which made it easy to extract palythine alone.’

Lawrence feels the study demonstrated the potential for using palythine as a bio-compatible sunscreen, since they used ‘solar-simulated radiation... and used endpoints that are directly relevant to photoprotection in humans, including DNA damage that has a direct link to skin cancers and markers of oxidative stress and photoageing.’

This was published in the February 2018 edition of Geographical magazine.

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