The chemical compounds that block UV rays may lead to bleaching of coral and a decrease in fish fertility.
Urgent investigation is needed into the potential impact sunscreen is having on marine environments, according to a new report.
Sunscreens contain chemical compounds, known as pseudo persistent pollutants, which block the sun’s ultraviolet (UV) rays and can lead to bleaching and deformity in coral or a decrease in fish fertility.
The global sunscreen market is booming, with sales predicted to reach $13.6bn by 2028. The products are washed off into the world’s oceans in surprisingly high volumes, according to the review. One featured study calculated that, assuming that 50% washes off, if the average person applies 36g of sunscreen with a reapplication of the same amount occurring after 90 minutes, a single beach with 1,000 visitors could lead to 35kg entering the ocean.
The review, published by the journal Marine Pollution Bulletin, looked at more than 110 publications linked to sunscreen, UV filters and their environmental and ecotoxicological impact. An estimated 6,000-14,000 tonnes of UV filters are released each year into coral reef zones alone, leading scientists to emphasise the growing need for comprehensive studies into the effects of sunscreen pollution on marine life.
“Current research has only scratched the surface of understanding how these chemicals can affect marine life,” says Anneliese Hodge, the study’s lead author and PhD researcher at Plymouth Marine Laboratory and the University of Plymouth.
“What’s particularly concerning is that these compounds are considered ‘pseudo persistent pollutants’ due to their continuous introduction into marine environments. We really need to understand how these chemicals interact in the marine environment and if they have the potential to bioaccumulate within the food chain.”
UV filters have been found in marine environments worldwide, from busy tourist spots to more remote locations like Antarctica. These compounds can enter marine spaces directly, such as through swimming, and indirectly through beach showers or towels that have been used to dry sunscreen-coated skin.
The most common compound found in UV filters is benzophenone. Benzophenones have been identified as persistent, bioaccumulative and toxic substances, with benzophenone-3, the chemical frequently found in sunscreens and cosmetic products, now under investigation as a possible hormone disruptor by the European Chemicals Agency.
UV filter pollution has also been detected in agricultural practices, when recycled water from wastewater treatment plants is used as soil fertiliser. The contaminants found here not only impact crops, but also reach aquatic environments through agricultural runoff.
Meanwhile, traditional sewage and water treatment technologies such as ozonation, a chemical process that uses ozone gas to remove pollutants, are ultimately ineffective in reducing the toxicity of UV filters.
“There are increasing amounts and varieties of sunscreens entering the environment, and contaminants occur in all possible combinations,” says Prof Awadhesh Jha, a senior author of the review and professor in genetic toxicology and ecotoxicology at the University of Plymouth.
Increased research across a range of geological regions, and more diverse testing at different marine life stages are among the review’s recommendations to better understand the problem of sunscreen pollution.