Coral decline -- is sunscreen a scapegoat?

February 02, 2021

Many household products contain ingredients to protect them against sun damage. These UV filters are found in plastics, paints and textiles, as well as personal care products such as sunscreens and moisturizers. UV filters are entering the aquatic environment in rivers, lakes and oceans. Consider for a moment a beach goer swimming in the ocean or rain washing over plastic playground equipment and running into a stormwater drain - either directly or indirectly, UV filters end up making their way to a waterway.

UV filters are chemicals that work by either physically blocking or absorbing UV rays. There are two main types of UV filters: inorganic forms, which contain metal particles, such as titanium dioxide (TiO2) or zinc oxide (ZnO) and physically block sunrays like little mirrors; and organic chemical UV filters, such as benzophenone-3 (BP-3 or oxybenzone) and octinoxate (EHMC), which chemically absorb UV rays.

In recent years, there has been a rapid increase in public, political and scientific interest in the effect UV filters have had on coral reefs; especially organic UV filters used in sun protection products. Coral reefs are important for biodiversity and provide great economic values, such as tourism and recreation. Significant decline in the diversity and abundance of coral in recent years has been attributed to climate change and longer-duration temperature events, which are exacerbated by human activities that cause coral bleaching, like overfishing and land run-off of nutrients and chemical pollutants. The impact of organic UV filters on corals has also been scrutinized and some regulatory bodies have even banned the sale of sunscreens containing certain organic UV filters.

A recent paper in the journal of Environmental Toxicology and Chemistry (ET&C) summarizes the scientific literature assessing the impact of organic UV filters on coral ecosystems. The researchers reviewed nine laboratory coral exposure studies investigating the biological effects of organic UV filters and 12 studies that provided information on the concentration of 14 different organic UV filters in seawater near coral reefs. They concluded that while organic UV filters do occur in the environment, there is limited evidence to suggest their presence is causing significant harm to coral reefs. However, the scientists caution that based on the limited information and data currently available, it would be premature to conclude that organic UV filters do not adversely impact coral reefs. The scientists pointed to the wide variations in experimental designs used and issues of data reliability, which makes it difficult to draw conclusions. They also pointed to numerous critical data gaps in terms of reliable and relevant environmental exposure and toxicity data that need to be filled before conclusions can be drawn. In their paper, Carys Mitchelmore and colleagues outline a number of recommendations for future studies to assess the environmental risk of organic UV filters to coral reef ecosystems. Mitchelmore adds, "In addition to more field and lab studies that take reef conditions and species into account, there is a need to develop a coral environment risk assessment framework. Investigating and prioritizing stressors on corals would allow regulators, policymakers and scientists to optimize conservation and management activities."

Society of Environmental Toxicology and Chemistry

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to