Screening Process: How a DES Lab is investigating the ecological impacts of sunscreen

 

BATON ROUGE - Summer is sunscreen season. Whether you are headed to the beach for the weekend or the neighborhood pool for the afternoon, slathering up with sunscreen to block the sun’s harmful effects is highly recommended by experts.

However, although sunscreen may protect human health, some of the chemical agents used in many common brands may cause harm to fish and other aquatic life, says Department of Environmental Sciences Assistant Professor Jon Doering.  

“Sunscreen chemicals are frequently detectable in tissues from marine mammals, seabirds, fishes, invertebrates, and aquatic vegetation, but the levels that cause toxicities are unknown for most of these chemicals,” Doering said.

Doering’s Aquatic Toxicology lab is investigating the environmental impacts of sixteen different organic chemicals - agents like oxybenzone and octocrylene that are used in widely available grocery store sunscreens. He wants to know what their impacts may be on aquatic life. “We’re looking to see what the impact of these chemicals is specifically on local creeks, local fish, and what is going into the Gulf,” Doering said.

The FDA regulates sunscreens to ensure products are safe and effective for consumers.

However, fish and other marine life may not be as lucky. Studies show the highest concentrations of chemical sunscreen agents in local waterways happen during the summer, in densely populated areas, where they may wash off swimmers, or enter through waste water discharges, since most municipal waste systems don’t remove them.

All of these entry points allow concentrations to rise.  

Doering and his students are using predictive toxicology approaches, which are animal alternatives because they require far fewer live samples than traditional toxicity testing methods.

They extract needed proteins from a single fish organ, and expose it to a variety of chemicals in sunscreens. “We know they interact with different proteins in your body and cause those proteins not to function properly, which is what can lead to toxicities…. We can extract those proteins that are being affected and then put those extracts into well-plates, and then from one fish, we can study multiple concentrations of all 16 chemicals,” Doering said.

Concern about chemical agents causing bleaching of coral reefs have already led to certain areas, including Hawaii and Key West, banning organic chemical sunscreens.  However, these chemicals likely also have negative effects on other aquatic life, possibly at lower levels than they do on corals.