Mercury Containing Devices (MCDs) include older thermometers,
thermostats, switches, and some light bulbs which contain elemental
mercury as well as mercury vapor; and many are used every
day in homes, schools and businesses. For example, fluorescent
lamps use less energy than traditional incandescent lamps; but,
unless handled, recycled, or disposed of properly, the vapor from
broken or discarded bulbs can contaminate air, surface water and
groundwater. If a fluorescent bulb is broken in a confined area, specific
steps should be taken to immediately evacuate the area to
avoid breathing and further spreading of mercury vapor (see the
section on Mercury Release, Spills or Breakage of MCDs). Other
MCDs such as mercury thermostats and switches are becoming
antiquated and costly to maintain; so as they are being replaced, it
is imperative they be handled appropriately.
One reason this is important is because mercury in the air eventually
settles into water, or onto land where it can be washed into water.
Certain microorganisms can then change it into methylmercury, a
highly toxic form that builds up in some types of fish and shellfish
making this the main source of exposure to humans. This buildup
occurs more in some types of fish and shellfish than others, and the
toxic levels depend on what they eat, how long they live, and how
high they are in the food chain. Fish advisories, the Environmental
Protection Agency (EPA,) the Food and Drug Administration (FDA)
as well as each state work to issue advice to women who are or
may become pregnant, nursing mothers, and parents of young children
about how often they should eat certain types of commercially
caught fish and shellfish. High levels of methylmercury in the bloodstream
of unborn babies and young children may harm their developing
nervous systems, impairing their ability to think and learn.
Fortunately, research shows that most people's average fish consumption
does not cause a health concern; however, when mercury
or MCDs are mishandled causing the release of mercury into the
environment, the exposure increases. Because high levels of mercury
can affect the brain, heart, kidneys, lungs, and immune system
of humans of all ages, mercury disposal is regulated by state and
federal laws. Improper disposal such as in municipal solid waste
collection facilities and landfills is forbidden; therefore, the following
are options for proper handling.