It is involved in several chemical processes, which are mostly related to our metabolism. (balticwonder.com)
The agency found that 5 of 64 homes tested had levels of several chemicals in their water that were sufficiently high to justify intervention (filtering). (dotearth.blogs.nytimes.com)
The result is that several chemicals with realistic chances of causing toxic effects can be found in everything from shampoo to toothpaste. (scientificamerican.com)