Mercury in NH's
is a naturally occurring metal that has many forms, including elemental
mercury used thermometers, inorganic mercury used in certain paints
and pesticides,and organic mercury, which is sometimes found in fish.
does mercury get into freshwater fish?
living in the sediments and water convert inorganic mercury into the
more toxic organic form. Mercury is part of the concern because it can
accumulate in fish at levels many times greater than in the surrounding
water. Small fish and other organisms living in the water can take up
mercury. When larger fish eat the smaller fish, much of the mercury
present in the small fish will be absorbed and stored in their bodies.
Therefore, large fish at the top of the food chain, like bass and pickerel,
can collect a relatively large amount of mercury.
can mercury affect my health?
has no purpose in the human body and when taken into the body may pose
a danger to human health. The low levels of mercury found in New Hampshire
fish do not cause immediate sickness. Mercury can, however, build up
in the body over time from ingesting contaminated fish. Exposure to
high levels of mercury can permanently damage the brain, kidneys, and
Children and Unborn Children
Children are more sensitive to mercury because their nervous systems
are still developing and more of it passes into their brains where it
interferes with normal development. A pregnant woman may pass mercury
to her unborn child through the placenta or a breastfeeding mother may
pass mercury to a nursing child through the breast milk. Typical adverse
effects that have been observed in children exposed to elevated levels
of mercury include delayed development, for example, a delay in the
time it takes before a child begins to walk.
The nervous system is very sensitive to all forms of mercury. In the
general population, the health effects associated with ingesting elevated
amounts of organic mercury include tingling or numbness in the hands,
feet or around the mouth. Vision and hearing may also be affected.
do we know mercury is a problem in freshwater fish?
more than 500 fish have been sampled and tested from approximately 100
lakes, ponds and rivers. Sample results have shown that levels of mercury
found in freshwater fish may be potentially harmful.
typically only a small number of fish -usually less than five per lake-
that are sampled from any given lake making it difficult to conduct
a specific assessment on any given water body. Because a wide range
of water bodies were sampled across the entire slate, these results
are anticipated to provide a fairly representative picture of fish mercury
levels throughout New Hampshire. Sample results have shown elevated
fish mercury levels to occur in lakes/ponds located in remote
pristine areas as well as more developed areas which indicates the problem
is more wide spread and not just limited lo certain locally impacted
fish may be contaminated should I stop eating freshwater fish?
is encouraged to continue eating fish as part of a healthy diet. Fish
are high in protein and low in saturated fat and cholesterol. A diet
low in fat contains fewer calories. Eating fish may play a part in reducing
the risk of certain cancers and heart disease. To reduce the exposure
to mercury, the Department of Health and Human Services recommends that
you limit the amount of freshwater fish in your diet according to the
guidlines listed below:
of childbearing age - One 8oz meal per month
Children under six years of age
- One 8oz meal per month
All other consumers - Four 8oz meals