Carbon nanoparticles toxic to adult fruit flies but benig...( PROVIDENCE R.I. [Brown University] ...)

PROVIDENCE, R.I. [Brown University] Carbon nanoparticles are widely used in medicine, electronics, optics, materials science and architecture, but their health and environmental impact is not fully understood.

In a series of experiments, researchers at Brown University sought to determine how carbon nanoparticles would affect fruit flies from the very young to adults.

The scientists found that larval Drosophila melanogaster showed no physical or reproductive effects from consuming carbon nanoparticles in their food. Yet adult Drosophila experienced a different fate. Tests showed adults immersed in tiny pits containing two varieties of carbon nanoparticles died within hours. Analyses of the dead flies revealed the carbon nanoparticles stuck to their bodies, covered their breathing holes, and coated their compound eyes. Scientists are unsure whether any of these afflictions led directly to the flies' death.

A separate experiment showed adult flies transported carbon nanoparticles and then deposited them elsewhere when they groomed themselves.

The findings, published online in Environmental Science & Technology, help to show the risks of carbon nanoparticles in the environment, said David Rand, professor of biology, who specializes in fruit fly evolution.

"The point is these same compounds that were not toxic to the (fruit fly) larvae were toxic to the adults in some cases, so there may be analogies to other toxic effects from fine particles," Rand, a co-corresponding author, said. "It may be like being in a coal mine. You get sick more from the effects of dust particles than from specific toxins in the dust."

The scientists immersed adult Drosophila in a control test tube and test tubes containing four different types of carbon nanoparticles corresponding with their commercial uses carbon black (a powder much like printer toner), C60 (spherical molecules known as carbon buckyballs, named for Buckmins
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