In the 18th and 19th centuries, hat makers commonly used mercury in their trade. Mercury poisoning was so common among hat makers that mercury poisoning was often called “Mad Hatter Disease.” In Danbury Connecticut, a leading center for hat making in the 19th century, mercury poisoning was referred to as the “Danbury Shakes.” In the United States, the use of mercury in hat making was banned in the early 1940s.
Mercury is a heavy metal found in the earth’s crust. Mercury poisoning occurs when mercury enters our bodies. This could happen by ingesting, inhaling, or through contact with our eyes or skin. A very small amount of mercury can be toxic to a human or pet.
Mercury poisoning can occur if an old-style thermometer or thermostat breaks and releases mercury into the area. Fluorescent lights also contain mercury that can be released if the fixture breaks. Workers in smelting sites, mining facilities, and fishing operations can be exposed to mercury. In today’s world, the most common way to be exposed to mercury is to consume large amounts of fish.
When mercury is released into nature, it often ends up in the rivers, lakes, and oceans, and is absorbed by aquatic plants. These plants are eaten by fish, which are eaten by larger fish. These larger fish tend to have higher amounts of mercury. Large prey fish, if eaten, should be consumed in moderation. Small children and women who are pregnant, may become pregnant, or are breastfeeding should avoid large predatory fish.
Fish is an excellent source of protein, and its healthy oils protect against cardiovascular disease. Because a diet rich in seafood protects the heart and aids neurological development, fish remains an important component of a healthy diet. The FDA recommends that adults should eat up to 12 ounces per week of a variety of cooked seafood as long as they limit large predatory fish and pay attention to local seafood advisories.
If you have mercury items, the Massachusetts Department of Environmental (MassDEP) recommends removing them from your home. You can call 866-9Mercury for information on safely disposing of these items.
MassDEP instructs, that if an item containing mercury breaks in your home and is less than two tablespoons of mercury, call MassDEP Mercury Programs Hotline at 866-963-7287 right away. Keep children and pets far away, avoid tracking the mercury through the house, and don’t try to clean it up yourself. Do not vacuum or sweep the mercury. Turn off your heat or air conditioning and open windows to increase ventilation. If the amount of mercury released is more than two tablespoons, this is an environmental emergency, call 911 or MassDEP 24/7 Spill Hotline at 888-304-1133 immediately.
If you work around mercury, if you are exposed to mercury spilled accidentally, or if you consume seafood, and you believe may have mercury poisoning, see your medical professional right away.
The following conditions can be indications of early mercury poisoning:
- Coughing
- Mouth sore or inflammation
- Increased salivation
- Diarrhea
- Nausea
- Vomiting
- Conjunctivitis
- Skin rash
- Difficulty sleeping
Later symptoms include more severe symptoms, such as:
- irritability and nervousness
- changes in mood
- excessive shyness
- tremors
- insomnia
- twitching
- weakness
- muscle atrophy
- partial leg paralysis
- headaches
- poor mental function
- changes in sensations
- memory changes
- personality changes
With proper treatment, mercury poisoning can usually be reversed. Much depends on the level of exposure. If a person does not receive treatment, they may experience kidney problems, respiratory failure, permanent lung damage, hypoxia, or death. Prompt treatment is critical to reverse the condition.