Mercury is commonly known as a toxic element, but many people don’t realize that the mercury in their thermometers can be a major hazard when not disposed of properly. Each year, thousands of pounds of mercury are haphazardly dumped into landfills, demolition dumps and incinerators, creating a significant threat for the environment and human health. The federal EPA estimates that 21 tons of mercury had been used in the production of thermostats as of 2004. Mercury poisoning in humans can cause: