I have wondered what happens when titanium dioxide nanoparticles in sunscreens wash off. Apparently, I’m not alone. Two scientists in Connecticut are studying marine biofilm (the slimy green stuff) found on rocks and docks at the seaside. According to a news item on Nanowerk,
While swimmers and boaters along any shore consider the slimy green film that coats everything from rocks to docks as a nuisance, University of New Haven (UNH) chemical engineering student Nicole Reardon and Assistant Professor Shannon Ciston, Ph.D. think otherwise. They view the slime, or biofilm, as a complex community that may hold the key to informing humanity of the true environmental impact of the chemical nanoparticles that find their way from area kitchens, baths and garages into Long Island Sound. One such controversial compound is titanium dioxide, which is used to whiten and brighten a multitude of products, including candy, cosmetics, toothpaste and paint.
… Noting that “large” particles of titanium dioxide are considered safe by the FDA, Ciston and Reardon are interested in how nanoparticles of titanium dioxode affect marine ecosystems, particularly in terms of the humble biofilm. Reardon explains that while marine biofilms can be a bother, they are critical players in the oceanic environment. In addition to transforming nitrogen and carbon in ways that positively impact the greater food web, biofilms clean waste water by eating harmful organic matter and can even be used to clean oil and gasoline spills through bioremediation.
I was hoping to find more information about this project on the University of New Haven website but they appear to have sent out a news release only. Unfortunately, Dr. Shannon Ciston’s webpage doesn’t offer any additional insight and I could not find a webpage for graduate student Nicole Reardon. My guess is that the lack of more information is due to the University of New Haven being a small university with limited resources. Bravo to their communications team for getting this project noticed and I hope to hear more about it as it progresses.