Fever Pitch on Mercury Fears

by Sandy Szwarc, RN, BSN, CCP

http://www.cei.org/pdf/4673.pdf

It’s enough to make any parent’s heart race: children evacuated from schools as hazmat teams race in to decontaminate the buildings, while national headlines scream, “highly toxic hazardous spill.” But when the source of this panic is a few beads of mercury from a broken thermometer, it’s time to take a deep breath and seek some sound information. Small mercury spills can be easily cleaned up and don’t pose a danger to children or their teachers—but panic-driven responses can cause real harm.

After finding small beads of mercury, about five to ten fever thermometers worth, officials at Washington, D.C.’s Cardozo High School evacuated the building and undertook a costly and elaborate “decontamination” at an estimated cost to taxpayers of $150,000. While it sent parents into a panic, it proved to be an amount that untrained adults could have cleaned up. In fact, after

simply picking up the liquid metal beads, health officials checked the level of mercury in the air and found it was about 25 times lower than levels at which the Centers for Disease Control and Prevention has found harm in children, even after years of such exposure.

Generations of children have been fascinated by the dancing beads of elemental mercury found inside thermometers—and today’s children are in no more danger than their parents were when they played with it as kids or when it was part of their childhood science classes. In fact, the amount of mercury in a typical fever thermometer is unlikely to threaten the health of even the most sensitive of people—children and pregnant women—according to the Illinois Teratogen Information Service (which provides free information on medications, chemicals, infectious diseases, or environmental agents that might interfere with healthy development).

In recent years, we’ve come to believe that any level of exposure to potential toxins is dangerous, but nothing could be further from the truth. Granted, we know more about the dangers of mercury today, but it is our perception of risk that has changed the most. The risks of mercury depend on the amount, type and duration of exposure. As with everything, the poison is in the dose.

Elemental mercury is not a health threat when handled or ingested, because virtually none (less than 0.1%) is absorbed through the skin or digestive tract. Left undisturbed, mercury will begin to vaporize. When breathed in and absorbed through the lungs, high levels of mercury vapor can be harmful. Vaporization happens very slowly over time, however. The Association for Science Education in the UK reports that negligible amounts of mercury are released from small spills even after 7 months.

Experts at the Environmental Protection Agency and elsewhere say spills the size of a quarter can be cleaned up by untrained adults. Cleanup involves simply scooping the mercury into a sealed plastic bag and airing out the room. Sprinkling zinc or copper flakes, available at hardware stores or found in the spill kits at most public buildings, will pick up any remaining traces. So, when school officials—or individuals at home—take basic steps to clean up spills, dangers can be easily eliminated.

Unfortunately, confusion arises when parents are told that their kids have been exposed to mercury levels above “safe” levels. Parents are never told that these thresholds have very large safety margins built in, so they are many times lower than levels at which any actual risk has ever been shown. According to the CDC, the lowest level where any adverse effect has been observed occurred in workers exposed for over 15 years to air mercury levels about 100 times higher than today’s “safe” levels.

Letting our fears get the better of reason can become costly. From 1993 through 1998, the CDC’s Hazardous Substances Emergency Events Surveillance system reported 406 such mercury spills, mostly in schools, universities, homes, and health care facilities. The EPA responded to 12 “emergency spills” in 2004, with clean-up costs as high as $200,000 each.

Even worse, the media attention given to mercury spills over recent years has stoked fears and even incited copycat pranks. Beads of mercury found at the Williamsburg City Council chambers earlier this year will cost about $250,000 to clean up, according to EPA estimates. A 2003 intentional spill closed Ballou High School for 35 days and rang up EPA cleanup costs of $1.5 million. And in March, a Hatfield, Massachusetts school was evacuated and a hazmat team called in when a thermometer in a science classroom simply began to leak, while teachers and a student were whisked to the hospital for unnecessary blood tests.

Sensationalizing danger doesn’t simply add more stress to our already stressful lives. Panic-driven responses can divert financial resources away from other priorities, including education. And that is a far greater risk to our children’s future.

Sandy Szwarc is a registered nurse and frequent writer on public health topics. She is the author of Fishy Advice: The Politics of Methylmercury in Fish and Mercury Emissions, recently published by CEI.