Up till now, nanoscale titanium dioxide in water has not been viewed as toxic to marine life. A newly released study by researchers from  the University of California (UC) Center for Environmental Implications of Nanotechnology (UC CEIN) in the Jan. 20 in the journal PLoS ONE suggests otherwise. From the Jan. 24, 2012 news release on EurekAlert,

“Previous experiments have suggested that TiO2 does not affect aquatic organisms, but these experiments used artificial lighting that generated much lower levels of UVR than sunlight,” Miller [lead author and assistant research biologist Robert Miller] explains. “In these new experiments, we used lights simulating natural sunlight.”

But now, the authors say, “We show that relatively low levels of ultraviolet light, consistent with those found in nature, can induce toxicity of TiO2 nanoparticles to marine phytoplankton, the most important primary producers on Earth.

So, the relatively low levels of ultraviolet light in natural sunlight can induce toxicity in titanium dioxide nanoparticles. Here’s the reason for the concern,

“Application of nanomaterials in consumer products and manufacturing is quickly increasing, but there is concern that these materials, including nanoparticles, may harm the environment,” says Miller. “The oceans could be most at risk, since wastewater and factory discharges ultimately end up there.”

In all of the kerfuffle that the Friends of the Earth (FoE) and The ETC Group (and I assume others as well) have made over nanoscale ingredients in sunscreens they seem to have ignored the impact that these ingredients, when washed off our skin and into our water supply, may have on aquatic life.  I wonder if that will matter in the end. I mean if it turns out that nanoscale titanium dioxide is going to kill/damage “… the most important primary producers on Earth”, does it matter if FoE and the others succeed in mobilizing opposition to its use for what most experts might consider the wrong reasons.