Mercury concentrations tend to be higher in larger, older fish and in fish from tea-colored and relatively acidic waters. Mercury exposure in humans can lead to a variety of negative health effects, including neurological, kidney, gastrointestinal, genetic, cardiovascular, and developmental disorders, and even death. Methyl mercury is transported across the blood-brain barrier and, in pregnant women, across the placenta into the fetus. Because methyl mercury inhibits the normal development of the nervous system in young children and fetuses, New Hampshire's fish advisory recommends that women of childbearing age and young children limit their consumption of freshwater fish to no more than one meal per month. In addition to the effect on humans, fish-consuming wildlife such as loons, eagles and otters are also at risk from mercury contamination.
Reproductive problems are the primary concern for birds suffering from mercury poisoning.
Other mercury effects in birds and mammals include liver damage, kidney damage, and neurobehavioral effects. New Hampshire has already taken steps to reduce mercury emissions and address mercury impacts in New Hampshire. Mercury reduction efforts have included eliminating mercury in batteries and packaging, promoting the recycling of mercury containing wastes such as paint and fluorescent lamps, and prohibiting the use of mercury containing pesticides. In addition, New Hampshire is the first state to develop a Mercury Reduction Strategy which calls for a 50 percent reduction in mercury emissions from sources in New Hampshire by the year 2003. By taking a leadership role to reduce its own emissions of mercury, New Hampshire is able to call for similar reductions on a regional, national and international level.