Dental amalgam controversy cause harm in patients." Also, in the FDA final regulation on dental amalgam in 2009, the FDA recommended the product labeling of dental amalgam. The suggested labeling included: a warning against the use of dental amalgam in patients with mercury allergy, a warning that dental professionals use appropriate ventilation when handling dental amalgam, and a statement discussion of scientific evidence on dental amalgam's risks and benefits in order to make informed decisions amongst patient and professional dentists. The use of mercury in dental fillings is considered safe and effective in all countries practicing modern dentistry (see below). There are currently
Environmental chemistry chemicals in what concentrations are present naturally, and with what effects. Without this it would be impossible to accurately study the effects humans have on the environment through the release of chemicals. Environmental chemists draw on a range of concepts from chemistry and various environmental sciences to assist in their study of what is happening to a chemical species in the environment. Important general concepts from chemistry include understanding chemical reactions and equations, solutions, units, sampling, and analytical techniques. A contaminant is a substance present in nature at a level higher than fixed levels or that would not otherwise be