Children may have highest exposure to titanium dioxide nanoparticles

Feb 15, 2012
Children may have highest exposure to titanium dioxide nanoparticles

Children may be receiving the highest exposure to nanoparticles of titanium dioxide in candy, which they eat in amounts much larger than adults, according to a new study. Published in ACS' journal, Environmental Science & Technology, it provides the first broadly based information on amounts of the nanomaterial – a source of concern with regard to its potential health and environmental effects – in a wide range of consumer goods.

In the study, Paul Westerhoff, Ph.D., and colleagues point out that titanium dioxide is a common additive to many consumer products, from food to paint to cosmetics. Westerhoff explained that the body releases the in feces and urine, sending them to wastewater treatment plants, which cannot prevent the smallest particles from entering lakes and rivers. Only one previous study, done a decade ago, reported on titanium dioxide content in a few commercial products. To fill the knowledge gap about the sources of humans' exposures, the researchers bought and tested food, personal care products, paints and adhesives and measured how much titanium dioxide they contain.

The group found that children consume more titanium dioxide than adults because sweets like candies, marshmallows and icing are among the products with the highest levels. The paper lists the names of the products tested and their titanium dioxide content. Westerhoff recommends that regulators shift their focus from the type of used in paints and industrial processes to food-grade particles, because those are much more likely to enter the environment and pose a potential risk to humans and animals.

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More information: Titanium Dioxide Nanoparticles in Food and Personal Care Products, Environ. Sci. Technol., Article ASAP. DOI: 10.1021/es204168d

Abstract
Titanium dioxide is a common additive in many food, personal care, and other consumer products used by people, which after use can enter the sewage system and, subsequently, enter the environment as treated effluent discharged to surface waters or biosolids applied to agricultural land, incinerated wastes, or landfill solids. This study quantifies the amount of titanium in common food products, derives estimates of human exposure to dietary (nano-) TiO2, and discusses the impact of the nanoscale fraction of TiO2 entering the environment. The foods with the highest content of TiO2 included candies, sweets, and chewing gums. Among personal care products, toothpastes and select sunscreens contained 1% to >10% titanium by weight. While some other crèmes contained titanium, despite being colored white, most shampoos, deodorants, and shaving creams contained the lowest levels of titanium (<0.01 μg/mg). For several high-consumption pharmaceuticals, the titanium content ranged from below the instrument detection limit (0.0001 μg Ti/mg) to a high of 0.014 μg Ti/mg. Electron microscopy and stability testing of food-grade TiO2 (E171) suggests that approximately 36% of the particles are less than 100 nm in at least one dimension and that it readily disperses in water as fairly stable colloids. However, filtration of water solubilized consumer products and personal care products indicated that less than 5% of the titanium was able to pass through 0.45 or 0.7 μm pores. Two white paints contained 110 μg Ti/mg while three sealants (i.e., prime coat paint) contained less titanium (25 to 40 μg Ti/mg). This research showed that, while many white-colored products contained titanium, it was not a prerequisite. Although several of these product classes contained low amounts of titanium, their widespread use and disposal down the drain and eventually to wastewater treatment plants (WWTPs) deserves attention. A Monte Carlo human exposure analysis to TiO2 through foods identified children as having the highest exposures because TiO2 content of sweets is higher than other food products and that a typical exposure for a US adult may be on the order of 1 mg Ti per kilogram body weight per day. Thus, because of the millions of tons of titanium-based white pigment used annually, testing should focus on food-grade TiO2 (E171) rather than that adopted in many environmental health and safety tests (i.e., P25), which is used in much lower amounts in products less likely to enter the environment (e.g., catalyst supports, photocatalytic coatings).

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User comments : 6

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Graeme
not rated yet Feb 15, 2012
Is there any evidence that these particles are harmful to eat? Soil and clay would be full of these kind of particles, so animal life would have been exposed for these constantly through geological history.
that_guy
not rated yet Feb 15, 2012
Titanium dioxide is an extremely abundant mineral, used in just about any white product. The environment has massive and varying amounts of TiO2 and we ingest large and varying amounts of TiO2.

I have never seen such an unsubstantiated alarmist article in my life. TiO2 is known to be an inert natural substance. Unless you can point to where it causes harm, don't scream about how it turns up everywhere.

This is almost as bad as worrying about people ingesting large amounts of hydrogen dioxide - It's possible to get intoxicated and die if you drink enough.
hagger
1 / 5 (1) Feb 16, 2012
why is it added...is it like floride..they cant dump it so they make up health benifits and put it out here..
that_guy
not rated yet Feb 16, 2012
why is it added...is it like floride..they cant dump it so they make up health benifits and put it out here..


It is used primarily as a white dye and to turn things opaque.

For example - It is in nearly all bright white paints, it's in skim milk, toothpaste, some chalk, paper, white plastic, even white people skin pigment...Ok, just kidding on the last one :).

It's not like flouride, where there is an intended therapeutic effect. It is primarily used cosmetically in consumer products.

It also makes a great catalyst in industrialized processes.
WesD
not rated yet Feb 17, 2012
Titanium dioxide is an extremely abundant mineral, used in just about any white product. The environment has massive and varying amounts of TiO2 and we ingest large and varying amounts of TiO2.

I have never seen such an unsubstantiated alarmist article in my life. TiO2 is known to be an inert natural substance. Unless you can point to where it causes harm, don't scream about how it turns up everywhere.


No where did I read anything that is cause for alarm? This is risk assessment 101. The ubiquitous nature of TiO2 is very well known, as is its stability. However, nano-sized TiO2 risk is not known. Toxicity studies are useless without exposure studies, which is what you are seeing here. No where does it state that TiO2 or even nano-TiO2 is toxic, just that it exists where many would not think it to be.
WesD
not rated yet Feb 17, 2012
Is there any evidence that these particles are harmful to eat? Soil and clay would be full of these kind of particles, so animal life would have been exposed for these constantly through geological history.


'That guy' seems to think bulk TiO2 is harmless, which for the general population is true. However, TiO2 can be a problem for people with Crohn's disease, and it is often not found on food labels of products containing TiO2. Furthermore, there are numerous studies on nano-sized TiO2 showing that there is an increased risk due to cellular disruption.