Does sunscreen damage freshwater lake ecosystems?

For this week we have provided a full transcript of our weekly Question.

Britt Wray: And now it's time for this week's Quirks & Quarks Question.

Mary Kainer: Hi, my name is Mary Kainer and I live in Toronto and I have a cottage in the north Kawarthas on beautiful Lake Kasshabog.

My question is: I hear a sunscreen is killing the coral in the oceans and I'm wondering what it's doing to our lakes? Does anyone know?

BW: And for our answer we go to Dr. Linda Campbell of St. Mary's University — and because Dr. Campbell is deaf, the voice you're hearing is that of SMU staff interpreter Ashley Campbell.

Linda Campbell: My name is Dr. Linda Campbell and I'm here in lovely Halifax, Nova Scotia, and I'm a professor here at St. Mary's University and an environmental scientist.

I'm here to answer the question from our listener, "Does sunscreen cause damage to freshwater lakes similar to the damage done in coral reefs?"

So the short answer [is] yes, but it does look different. The impacts unfortunately of many types of UV filters found in common sunscreen brands really are known to kill the organisms that form coral reefs. And as you know, Hawaii just recently actually banned many types of sunscreen.

Now freshwater lakes are not immune to the impacts from these UV filters similar to coral reefs. And there are two kinds that we are worried about: One is the carbon-based UV filters and the other is nano-particulate UV filters, and that's using zinc and titanium. Both of these types of filters negatively impact algae and fish in lakes.

The damage isn't as obvious and as visible as the bleaching to coral reefs, but they're still there — and the damages for example include DNA damage, bio-accumulation of harmful chemicals, and lower quality and quantity of food sources at the base of the food web.

It's easy to find sunscreen brands that contain less harmful components for the ecosystem and they don't have those nano-particulates, or have less harmful UV filters within them.

You can do some research online and look for coral reef-friendly sunscreen and then you can find those brands online quite easily and it's less harmful to the ecosystem.