Sunscreens could be toxic for health--study
POSTED April 9, 2010 - 12:13 | POSTED BY Kangna Agarwal
Last edited by Harpreet Bhagrath on April 9, 2010 - 12:41
A study conducted by researchers at the Department of Pharmacology and Toxicology of University of Utah, U.S., shows that sunscreens contain nanoparticles of zinc oxide, which is toxic in nature and can harm the colon cells if eaten accidentally.
To come up with this finding, the researchers carried out lab experiments with cell cultures of colon cells and compared the effects of zinc oxide nanoparticles to larger sized zinc oxide particles sold as a conventional powder.
Sunscreen nanoparticles found to be toxic
They found that nanoparticles of zinc oxide,smaller than 100 nano metres, were two times more toxic to the cell cultures of colon cells than the conventional zinc oxide.
The concentration of nanoparticles that was toxic to the colon cells was equivalent to eating two grams of sunscreen--about 0.1 ounce, reports the Times of India.
The scientists also found that solid zinc oxide was more toxic than equal amounts of soluble zinc and direct particle to cell contact was needed to cause cell death.
Thus it was established that particle size affects the toxicity of zinc oxide, which is added in sunscreens to prevent the damaging effects of harmful ultra violet (UV) rays.
"There is ongoing concern about the potential toxicity of nano particles of various materials, which may have different physical and chemical properties than larger particles. Barely 1/50,000 the width of a human hair, nano particles are used in foods, cosmetics and other consumer products," the Indian Express quoted lead author Philip Moos as saying.
"Unintended exposure to nano-sized zinc oxide from children accidentally eating sunscreen products is a typical public concern, motivating the study of the effects of nanomaterials in the colon," he added.
More research required
Despite the promising results of the study, scientists have outlined the need for more research to confirm the findings in animal and human subjects.
They will aim at determining whether zinc nanoparticle toxicity occurs in laboratory animals and people as well.
The study appears in ACS’ Chemical Research in Toxicology, a monthly journal.
