The researchers claim that their work took a closer look for first time at the levels of nano titanium dioxides in a range of consumer goods, in an effort to assess the specific risks to the consumer groups that are targeted by these products.
The study, which was headed by Paul Westerhoff, Phd, and published in the American Chemical Society journal Environmental Science Technology, underlines that nano titanium dioxide is now a common ingredient in a number of consumer product categories, including paint, pharmaceutical, food and cosmetics.
Focus on cosmetics and foods
The scientists chose to focus on the two latter categories, mainly due to the fact that consumers tend to have the most exposure to these product areas, and is claimed to be one of the most comprehensive assessments on levels of nanomaterials in these products.
The study is claimed to be the only the second comprehensive scientific study that has assessed the levels of nanomaterials in consumer products, while the last one was conducted ten years ago.
To carry out the analysis on the products, the researchers bought a variety of consumer products that are readily available in retail outlets. For personal care and cosmetics products that included toothpaste and sunscreen, skin care products, shaving creams and deodorants.
Highest levels in toothpaste and sunscreen
The study found that toothpaste and sunscreens contained the highest amount of titanium dioxide by weight at 1 percent to >10 percent titanium by weight.
The results found that while other crèmes contained titanium dioxide, even though they were colored white, most shampoos, deodorants, and shaving creams contained the lowest levels of titanium (<0.01 μg/mg).
However, despite the fact that the products contained low levels of nano titanium dioxide, the researchers also pointed out the potential risks of the ingredient contaminating waterways and sewerage systems and the potential risk this can have as an accumulative effect.
Risk to waterways and landfills
The authors of the study pointed out that once the ingredient is expelled from the body it can enter the sewage system and because there is no way of filtering such tiny nanomaterials it is hard to stop it infiltrating the environment.
This means that once effluent is discharged from waste water treatment plants it can invariably end up in surface waters or biosolids that are applied to agricultural land, incinerated wastes, or landfill solids.
Besides the risk to the waterways and landfills posed by nano titanium dioxide, the study also found that children are at particular risk of exposure to the ingredient, as the highest traces were found in candies such as icing, marshmellow and chewing gum.
Environ. Sci. Technol., Article ASAP
DOI: 10.1021/es204168d
Publication Date (Web): January 18, 2012
American Chemical Society