Introduction
Titanium dioxide particles are manufactured in huge quantities with scientists estimating that their annual production is well over 2 million particles. Besides their use in the manufacture of sunscreen and vitamins, paint, and cosmetics, nanoparticles are also found in food colorants, nutritional supplements, toothpaste, and many other personal care products. A detailed study undertaken by the Jonsson Comprehensive Cancer Center researchers at UCLA revealed Titanium dioxide particles led to systemic genetic damage when applied on mice subjects (Irwin para. 1). Titanium dioxide nanoparticles stimulated chromosomal damages on double and single DNA strand breakages and inflammation, thereby enhancing the risk of cancer. Because nanotechnology and nanoscience provide novel opportunities for the manufacture of sophisticated materials for health and industrial applications, it is still not certain the extent to which such materials may have on the environment as they gain widespread popularity.
Uses
The production of TiO2 nanoparticles is proving to be an important industrial venture owing to the strong demand for such materials. In 2010, it is estimated that the production of nanoparticle TiO2 was well over 50, 400 tons. This is a mere 0.7 percent of the entire TiO2 market. Scientists project that by 2015, the production will have reached 201, 500 tons. The plastics, pigments, paints, sunscreens, cosmetics, catalysts, skincare, glass and printing ink are the main end market. There is a rising demand for TiO2 nanoparticles from developing countries and the Asian market. For example, the Chinese market is currently undergoing rapid growth and as a result, there is high demand for photocatalytic TiO2 nanoparticles for use as deodorizing and self-cleaning agents (Chen et al 2394).
Since the TiO2 nanoparticles are small in size, they have gained widespread popularity in the cosmetic industry since they are easily absorbed through the skin. For this reason, they are used as moisturizers. Titanium dioxide reflects visible light quite well because it is a white powder and for this reason, it has found use in the manufacture of paint. It also finds use in skincare and cosmetic industry as a thickener, pigment, and moisturizer, as well as a UV absorber in sunscreens. Titanium dioxide nanoparticles have to be first coated before they can be incorporated as ‘sun blockers’ to overcome skin irritation. Owing to their small size, titanium dioxide nanoparticles tend to be colorless and are still able to absorb UV light, a characteristic that has led to their use in sunscreens (Lavicoli et al 482). On the other hand, the small size of titanium dioxide nanoparticles is also a risk factor because they can easily penetrate the cells, resulting in cell photocatalysis and damage to DNA upon exposure to the sunlight.
Possible effects on health
Because nanoparticles also act as primary building blocks for a number of nanomaterials, they can easily get suspended in the air during manufacture, distribution, as well as during application. Consequently, manufactured nanoparticles are now part of outdoor and indoor environments, including the air that we breathe. Since such particles fall well within the respirable size range, there is the need to examine the possible health implications of such particles when suspended as aerosol in the air. When absorbed into the body, TiO2 nanoparticles may accumulate in various organs since the body is not able to eliminate them. On to their small size, they are also able to penetrate cells, thereby inhibiting sub-cellular mechanisms (Chen et al 2394).
Recent research studies carried out on pregnant mice indicate that nanoparticles may cross the placenta barrier, resulting in neurotoxicity of offspring. However, it is still not clear how the impact of the nanoparticles on pregnant animals. In their study, Yamashita et al (322) demonstrate that titanium and silica nanoparticles with diameters of 35nm and 70 nm respectively, may lead to complications during pregnancy when pregnant mice are injected intravenously. The researcher found traces of titanium and silica nanoparticles in the fetal liver, placenta, and fetal brain. In addition, the scientists discovered that the fetuses and uteri of mice treated with titanium and silica nanoparticles were smaller, in comparison with the uterated controls. The study further showed that larger silica and Fullerene molecules of between 300 and 1,000 nm failed to induce such complications. The study associated such detrimental complications to functional and structural abnormalities on the maternal placenta.
Another study conducted by Chen et al (2395) argues that inhaling titanium dioxide particles may induce pulmonary toxicity. Nonetheless, its mechanism still remains unclear. In their study, the researchers sought to examine the pulmonary toxicity associated with titanium dioxide nanoparticles, along with its molecular pathogenesis (Jiaen 1025). The researcher exposed adult male ICR mice to a single dose of intracheal of between 0.1 and 0.5 nm nanoTiO2.. On the 3rd day of the experiment, the scientists collected lung tissues of the specimen. The procedure was repeated after 1 and 2 weeks (Yamashita 324). The lung tissues collected were subjected to pathway and microarray gene expression analyses. The research findings revealed that NanoTiO2 may induce macrophages accumulation, pulmonary emphysema, and epithelial cell apoptosis (Trouiller et al 8784). This shows that nanoTiO2 may trigger severe pulmonary emphysema, thereby resulting in PIGF activation.
Conclusion
Titanium dioxide particles are manufactured in huge quantities and due to their widespread availability, they have found use in the manufacture of cosmetics, food colorants, sunscreen paint, toothpaste, and many other personal care products. The small size makes the absorption of titanium dioxide nanoparticles into the body easier. Their accumulation at the cellular level can inhibit the subcellular mechanism. Studies on mice reveal that titanium dioxide nanoparticles can cross over the placenta barrier in pregnant mice, leading to neurotoxicity of the offspring.
Works Cited
Chen, Huaei-Wen et al. “Titanium dioxide nanoparticles induce emphysema-like lung injury in mice”. The FASEB Journal, 20(2006): 2393-2395.
Lavicoli, Ivo, Veruscka, Fontana, Laura, and Bergamaschi, Andrea. “Toxicological effects of titanium dioxide nanoparticles: a review of in vitro mammalian studies”. Eur Rev Med Pharmacol Sci, 15. 5(2011):481-508.
Jiaen, Jasmine, Muralikrishnan, Sindu Ng, Cheng-Teng, Yung, Lin, and Bay, Boon-Huat. “Nanoparticle-induced pulmonary toxicity”. Exp Biol Med, 235.9: 1025-1033
Trouiller, Benedicte, Reliene, Ramune, Westbrook, Aya, Solaimani, Parrisa, and Schiest, Robert. “Titanium Dioxide Nanoparticles Induce DNA Damage and Genetic Instability In vivo in Mice”. Cancer Res, 69(2009): 8784
Yamashita, Kohei et al. “Silica and titanium dioxide nanoparticles cause pregnancy complications in mice”. Nature Nanotechnology, 6(2011): 321- 328