Do sunscreen and boat bottoms hurt sea urchins?

"At low levels, both of these nanomaterials are nontoxic," says Gary Cherr. "However, for sea urchins in sensitive life stages, they disrupt the main defense mechanism that would otherwise protect them from environmental toxins." (Credit: Natalie Woo/Flickr)

Nanomaterials in sunscreens and on boat-bottom paints make sea urchin embryos more vulnerable to toxins, report researchers.

They say the materials could pose a risk to coastal, marine, and freshwater environments.

Their study in Environmental Science and Technology is the first to show that the nanomaterials work as chemosensitizers. In cancer treatments, a chemosensitizer makes tumor cells more sensitive to the effects of chemotherapy.

Similarly, nanozinc and nanocopper made developing sea urchin embryos more sensitive to other chemicals, blocking transporters that would otherwise defend them by pumping toxins out of cells.

Nanozinc oxide is used as an additive in cosmetics such as sunscreens, toothpastes, and beauty products. Nanocopper oxide is often used for electronics and technology, but also for antifouling paints, which prevent things like barnacles and mussels from attaching to boats.

“At low levels, both of these nanomaterials are nontoxic,” says coauthor Gary Cherr, professor and interim director of the University of California, Davis, Bodega Marine Laboratory, and an affiliate of the UC Davis Coastal Marine Sciences Institute.

“However, for sea urchins in sensitive life stages, they disrupt the main defense mechanism that would otherwise protect them from environmental toxins.”

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Nanomaterials are tiny chemical substances measured in nanometers, which are about 100,000 times smaller than the diameter of a human hair. Nano-sized particles can enter the body through the skin, ingestion, or inhalation.

They are showing up more and more in fields like electronics, medicine, and technology, where they are being used to make energy efficient batteries, clean up oil spills, and fight cancer, among many other uses. However, relatively little is known about nanomaterials with respect to the environment and health.

This research is part of the University of California Center for the Environmental Implications of Nanotechnology and supported by the National Science Foundation and the Environmental Protection Agency.

Source: UC Davis