Heavy Metal Toxins: Outside and Inside

Gina Temple-Rhodes
Western Lake Superior Sanitary District, Duluth, MN

Lead and Mercury. Toxic Heavy Metals. Brain toxins. Do these sound like far-away problems for scientists to ponder? Guess again. Both mercury and lead can often be found in our own kitchens, homes and even grocery stores. Exposure to these heavy metals can cause memory, reproductive and nervous system problems for adults and affect the brain development of babies and young children. By learning more about these toxins and taking certain precautions, you can reduce the effects from these indoor and outdoor hazards.

Both mercury and lead are elements found naturally in the earth. However, human activities like burning coal, processing metals and formulating paint have caused large amounts of these elements to enter into the atmosphere and into the food chain and eventually into our own bodies. As scientists learn more about the dangers of these atmospheric elements, many purposeful uses have been stopped. For example, mercury is no longer used as a fungicide in paint and it is also being phased out of thermometers and thermostats. Yet, unfortunately we’ll be living with the legacy of this pollution for years to come.

Mercury is found in many of the fish caught in Minnesota and around the world. After mercury is released into the atmosphere, it hitch-hikes in raindrops which fall into our lakes and rivers. There it is transformed to a toxic, biological form by tiny bacteria in the sediments. Small creatures at the bottom of the food chain absorb this toxin. As the smaller creatures are eaten by larger creatures in our Minnesota lakes and rivers, the mercury becomes more concentrated in the bodies of these larger creatures. In Minnesota, longer-lived predator fish and fish higher up the food chain like walleyes and northern pike have been tested with high concentrations.

Because mercury exposure is especially harmful for pregnant women and young children, they should limit their consumption of certain large fish, including some types of tuna, shark, swordfish, king mackerel or tilefish. Information on contamination levels for many of our Minnesota lakes and rivers is available from the MN Department of Health.

Up to two thirds of other mercury deposits come from human activities such as energy production and mining. Conserving electricity can help reduce those emissions. See the ENERGY section for energy-saving tips. Other ways to reduce mercury emissions are to properly dispose of any mercury-containing devices including older thermometers and thermostats that contain mercury and can be hazardous if broken. Fluorescent bulbs, which are valuable tools in conserving energy, also contain a small amount of mercury and must be disposed of properly. All of these materials should be brought to your county household hazardous waste facility for free disposal. Never place mercury in the garbage! Check your local hardware store for a more convenient fluorescent bulb drop off location.

Lead was used in outdoor and indoor paints for years in the United States before being banned in 1978. If you live in a house built before 1978, chances are good that lead paint can be found under layers of fresher paint on your window sills or interior or exterior walls. Chipping, flaking paint allows this element to circulate in and around your home where it can be inhaled or consumed. Children are especially vulnerable to this brain toxin. They are often exposed to lead through chewing on paint chips from painted surfaces because it tastes sweet or even just by putting their hands and toys into their mouths after touching affected surfaces. Some costume jewelry or pottery can also contain dangerous levels of lead.

You can help to avoid lead exposure by keeping your home’ paint maintained and immediately cleaning up any flaking paint. In addition, home renovations can release dangerous levels of lead; never attempt to sand off lead paint, as the tiny particles created can increase exposure. Consult your local health department for ideas to reduce your family’ exposure to lead. Bring any materials suspected of containing lead to your County’ household hazardous waste facility for proper disposal.

Heavy Metal

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