Market analysis of some mercury-containing products and their ...

Mercury-containing fever thermometers have been made from relatively inexpensive
glass tubes housing a small reservoir of mercury. This mercury expands at a known
rate due to its physical relationship to temperature. Placing a scale on the glass tube
allows for measurement of this expansion. Gas, liquid or other materials that come in
sufficient contact with the glass impart their temperature on the mercury and allow for
their temperature to be measured. Mercury contracts as the thermometer cools, but not
necessarily uniformly. This often requires the user to shake the thermometer to re-pool
the mercury into the lower end to get a proper reading. Environmental releases occur
when a health care provider or home user break the thermometer and/or improperly
dispose of the mercury contained within. Patients have been known to bite the thermometers
to the point of breakage, but the most frequent releases occur when mishandling
the glass thermometer results in breakage.
Sphygmomanometers measure blood pressure by using air pressure to displace a column
of mercury. Once pressure is created by pumping up a tourniquet cuff wrapped
around a patient’s extremity, the blood pressure is then read through a scale placed on
the mercury column. Systolic and diastolic pressures are identified by a health professional
monitoring the patients pulse through a stethoscope as pressure in the tourniquet
is released. Maintenance and calibration is required due to the loss of mercury
from the reservoir due to its connection to the ambient air. Environmental releases occur
during maintenance and use since the device has direct exposure to open air. Larger
amounts are released after breakage and/or disposal of these items. Aneroid (mercury-free)
sphygmomanometers eliminate the mercury column and work directly with
the air pressure to develop a reading. The pressure is then read through an analogue
or digital readout.
Dental amalgam is made of approximately 50% silver with small amounts of copper
and tin mixed with 50% mercury. Amalgam is a durable, malleable material with antimicrobial
properties. For over a century, these properties have lent themselves to use
in dental restorations where tooth decay has only partially affected the tooth. Low levels
of mercury are released throughout the lifetime of the amalgam exposing their
owner. Environmental mercury releases can occur both when amalgam materials are
first placed and/or when they are removed. In addition, with increases in dental care
and the growing use of cremation for dealing with loved ones after their death, large
amounts of mercury from amalgam restorations now get volatilized directly to the at-
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