LAKELAND, Fla., US: Although an increasing number of dentists and patients are choosing resin composites as restorative materials, amalgam is still widely used despite its disadvantages, such as poor aesthetics, harm to the environment and evidence that it may have harmful health effects on human health. Adding to the existing evidence on amalgam toxicity, a new study examined the impact of mercury vapour exposure from amalgam among pregnant American women and found that a large number of cases exceeded the safety limits set by the US Environmental Protection Agency. The finding is especially troubling in the light of the heightened risk of harmful effects on the foetus caused by exposure to mercury vapour during pregnancy.