Nanoparticles in sunscreens could be toxic if accidentally eaten
June 24th, 2010 - 2:08 pm ICT by ANIWashington, June 24 (ANI): Nanoparticles in sunscreens could be toxic if accidentally eaten, according to scientists.
Philip Moos and colleagues have said that particle size affects the toxicity of zinc oxide, a material widely used in sunscreens.
Particles smaller than 100 nanometers are slightly more toxic to colon cells than conventional zinc oxide.
Solid zinc oxide was more toxic than equivalent amounts of soluble zinc, and direct particle to cell contact was required to cause cell death.
The researchers noted that there is ongoing concern about the potential toxicity of nanoparticles of various materials, which may have different physical and chemical properties than larger particles.
Barely 1/50,000 the width of a human hair, nanoparticles are used in foods, cosmetics and other consumer products. Some sunscreens contain nanoparticles of zinc oxide.
“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,” noted the scientists.
Their experiments with cell cultures of colon cells compared the effects of zinc oxide nanoparticles to zinc oxide sold as a conventional powder.
They found that the nanoparticles were twice as toxic to the cells as the larger particles.
Although the nominal particle size was 1,000 times larger, the conventional zinc oxide contained a wide range of particle sizes and included material small enough to be considered as nanoparticles.
The concentration of nanoparticles that was toxic to the colon cells was equivalent to eating 2 grams of sunscreen - about 0.1 ounce.
This study used isolated cells to study biochemical effects and did not consider the changes to particles during passage through the digestive tract.
The scientists say that further research should be done to determine whether zinc nanoparticle toxicity occurs in laboratory animals and people.
The study is in ACS’ Chemical Research in Toxicology, a monthly journal. (ANI)
- Sunscreen nanoparticles could be toxic if accidentally eaten - Apr 08, 2010
- Nanoparticles in sunscreen toxic if ingested - Apr 09, 2010
- Sunscreen chemical may cause cancer - Dec 01, 2011
- Nanoparticles in English ivy 'key to making sunscreen safer, more effective' - Jul 20, 2010
- Nanoparticles may have negative effects on environment and human health - Sep 14, 2009
- Now, a method to predict nanoparticle interaction with human body - Aug 16, 2010
- Now, power your home with 'solar paint' - Dec 22, 2011
- Nanoparticles in common cosmetics, paints may cause genetic damage - Nov 17, 2009
- Kids most exposed to harmful nanoparticles - Feb 16, 2012
- Silica cages help anti-cancer antibodies prevent tumour growth in mice - May 22, 2010
- Tiny gold and silver nanoparticles could revolutionize optics - Dec 04, 2010
- Bacteria-killing paper for next-generation food packaging - Feb 20, 2011
- Now, 'nano cocktail' to target and kill tumours - Jan 05, 2010
- 'Super sand' to purify drinking water - Jun 23, 2011
- Study casts doubts on safety of invisible nano-sunscreens - Mar 08, 2010
Tags: biochemical effects, cell cultures, cell death, colon cells, digestive tract, further research, june 24, laboratory animals, nanomaterials, nanometers, ounce, particle size, particle sizes, particles, physical and chemical properties, public concern, sunscreen products, toxicity, width of a human hair, zinc oxide