Antique mirrors should be put on the list of dangerous substances, and not because of the risk of injuries from broken glass or seven years bad luck. The mercury and tin backing found on antique mirrors can damage your heart, kidneys, lungs, brain and immune system. The Centers For Disease Control (CDC) has released a study citing the dangers of mercury poisoning from broken or damaged antiques. Everyone knows that old thermometers and barometers contain mercury, but less commonly acknowledged is the presence of fairly large quantities of mercury in pendulum clocks and floor and desk lamps. Collectors of old medical equipment are also at risk for the mercury to be found in blood pressure cuffs and various gauges. According to the CDC, the danger lies in the deteriorating state of the antiques themselves as the seals age or the objects are dropped or damaged. The CDC report includes case studies that detail the mercury spillage and the steps necessary to abate it.
Mercury spills are difficult to deal with due to the nature of the chemical, and the CDC urges contacting the EPA in the event of a spill. When disturbed, mercury breaks into tiny, skittery balls that scatter at the merest disturbance. Mercury is on the EPA's list of hazardous materials, and requires a specially trained and equipped team for cleanups. Vacuuming is out of the question because heat from the appliance vaporizes the mercury and creates harmful fumes. The Haz Mat teams hand gathers all the visible mercury beads as well as the surface it spills on, especially carpet. Air samplings are then taken for as many days after the spillage as are require to ensure acceptable air quality.
Included in the CDC study is a list of potentially dangerous items including thermometers, barometers, pendulum clocks, thermostats and silvered mirrors and vases. They recommend that collectors of items such as barometers and pendulum clocks inspect their items carefully for broken or deteriorating seals, cracks, and leaks. Pendulum clocks frequently include mercury filled vials, and some manufacturers used mercury to weight the bases of floor and desk lamps. These items should be transported with great care, carefully packed, and placed in a leak proof container when possible.
The CDC reports that approximately twelve states have enacted legislation to prohibit the sale of items containing mercury. Maine is one of them. Home of the Maine Antique Digest, editor Clayton Pennington has observed that the legislation is like cracking a nut with a sledgehammer. Mercury legislation varies widely from state to state in terms of what is permissible for sale. In Oregon, Michigan, Indiana, and Maryland, there are laws controlling the sale of thermometers but not barometers. It is unclear whether it is legal to sell a combination case thermometer/barometer. Mercury filled glass tube pendulums on regulator clocks seem to be flying under legislators' radar at this point. Ironically, mercury came into use in regulators when it was discovered that it was impervious to weather conditions that affected the accuracy of the timepieces. Between legislation prohibiting sale and the scarcity and difficulty of obtaining mercury for repairs, antique clock and barometer dealers are feeling the squeeze, however in Maine at least legislation was passed recently to permit the sale of barometers over 100 years old.
