Aug. 1 (UPI) -- New research confirms the danger sunscreen chemicals poses to marine life.
Chemical filters used in sunscreen help protect skin from ultraviolet radiation. Recent sampling efforts off the coast of Shenzhen, China, revealed elevated levels of the filtering chemicals used in sunscreen.
Lab tests have shown filtering chemicals can harm fish embryos. However, scientists have expressed doubt as to whether filtering chemicals can persist in great enough concentrations to impact animal or human health.
In a series of new tests, scientists decided to look at whether myriad chemicals, at low concentrations, could combine to affect the health of fish embryos.
During the initial water sampling phase, scientists identified nine of 11 popular filtering chemicals in samples collected at Shenzhen's public beaches and harbor. Surprisingly, researchers also found filtering chemicals in the city's reservoir and tap water samples.
When scientists fed brine shrimp exposed to elevated levels of filtering chemicals to zebrafish, they found the zebrafish's offspring developed a variety of abnormalities.
"Aqueous exposure of fish embryos to mixtures of the three UV filters demonstrated a general trend of decreased heart/hatching rate as doses increased, coupled with significant changes in activities of catalase and malate dehydrogenase," researchers wrote in their paper on the subject.
Development abnormalities were most likely to occur after longer periods of exposure and at levels unlikely to occur in the environment.
However, the tests suggest different combinations of chemicals have the potential to have unpredictable impacts on animal health. To better understand the potential for harm, more testing is needed.
Scientists published their findings in the journal Environmental Science and Technology and are scheduled to present their work later this month in Boston at the American Chemical Society's annual meeting.
Previous studies have shown sunscreen chemicals can harm coral health.