August 22, 2014
Sunscreen Chemicals Could Be Hazardous To Marine Phytoplankton
redOrbit Staff & Wire Reports - Your Universe Online
Be careful with the sunscreen the next time you hit the beach for your vacation, as new research appearing in the journal Environmental Science & Technology suggests some ingredients in the protective substance could be harmful to some forms of marine life.
In their study, experts from the Mediterranean Institute for Advanced Studies (IMEDEA), a research center jointly operated by the Spanish National Research Council and the University of the Balearic Islands (UIB), and the Andalusian Marine Sciences Institute (ICMAN) report that certain types of sunblock ingredients wash off the skin and into the sea, where they become toxic to smaller marine animals used for food by larger creatures.
The study authors, Antonio Tovar-Sanchez and David Sánchez-Quiles, explained that the titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles which are found in sunblock can react with UV light from the sun and form hydrogen peroxide (H2O2), “a strong oxidizing agent that generates high levels of stress on marine phytoplankton.”
Their results indicated that those inorganic oxide nanoparticles could produce H2O2 at rates of up to 463 normal cubic meters per hour (nM/h) in seawater – hydrogen peroxide levels high enough to adversely affect phytoplankton growth, harming the microscopic algae that serve as food for small fish, shrimp, whales and other species.
In a statement released on Wednesday by the American Chemical Society, Tovar-Sanchez and Sánchez-Quiles detail how they traveled to Majorca Island’s Palmira beach on the Mediterranean in order to investigate the issue.
They combined seawater sampling and laboratory tests with data from regional tourism records, and concluded that TiO2 from sunblock was largely to blame for a significant spike in H2O2 levels in coastal waters during the summer. Those elevated hydrogen peroxide levels could have “potentially dangerous consequences for aquatic life.”
“Conservative estimates for a Mediterranean beach reveal that tourism activities during a summer day may release on the order of 4 kg of TiO2 nanoparticles to the water and produce an increment in the concentration of H2O2 of 270 nM/day,” Tovar-Sanchez and Sánchez-Quiles wrote. “Our results… point to TiO2 nanoparticles as the major oxidizing agent entering coastal waters, with direct ecological consequences on the ecosystem.”
Despite their findings, the researchers told the Daily Mail that sunscreen is still the best way to protect human skin from hazardous UV rays, provided that staying indoors is not an option. Nonetheless, when beachgoers head into the water to cool off, some of the sunblock’s chemicals can wash off into the sea.
In related news, a research team led by Corey Basch, an associate professor in the department of public health at William Paterson University in New Jersey reported on Thursday that the number of US teens using sunscreen had decreased nearly 12 percent, from 67.7 percent in 2001 to 56.1 percent in 2011.
Basch told HealthDay News reporter Steven Reinberg that she was not certain what was behind the trend, but that future research should be focused on finding out why teens are becoming less likely to use sunblock. However, she noted that this and similar protective behaviors would be essential to reducing skin cancer risk.