Nanoparticles are toxic - study confirms

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By Jimmy Downs

Friday Feb 8, 2013 ( -- Some dietary supplement manufacturers use zinc oxide in their products as a nutrient.   Like many other types of nanoparticles such as titanium dioxide and silicone dioxide, zinc oxide nanoparticles are toxic, according to a study in Environmental Science: Processes & Impacts.

Mehmet Ates conducted the study and found many shrimp larvae died after a 96-hour exposure to zinc nanoparticles or zinc oxide nanoparticles.

For the study, brine shrimp (Artemia salina) larvae were exposed to  zinc or zinc oxide nanopartilces of different sizes at different concentrations for 24 hours or 96 hours.

It was observed that nanoparticles accumulated inside the guts and shrimp larvae could not eliminate the ingested nanoparticles.  No acute effects were observed within 24 hours of exposure, but the mortality increased drastically within 96 hours and high concentrations of nanoparticles resulted in high death rates.

Zinc nanoparticles were found more toxic than zinc oxide nanoparticles.   

The toxicity was associated with the size of the particles.  Zinc nanoparticles in 40 to 60 nm were more toxic than 80 to 100 nm zinc nanoparticles and 10 to 30 nm zinc oxide nanoparticles were more toxic than 200 nm nanoparticles.

Nanoparticles are commonly used in processed food, dietary supplements, and cosmetics. The commonly used nanoparticles include titanium dioxide, silicone dioxide (or simply silica), and zinc oxide.   

Research has found that ingested nanoparticles can enter cells and disrupt DNA leading to genomic toxicity, potentially mutations which can eventually lead to cancer development.  Inhaled nanoparticles like silica has been recognized as a human carcinogen by the World Health Organization.

Those who want to avoid nanoparticles should check the ingredient list.  The names of nanoparticles end commonly with oxide or dioxide.
