One of my Chemistry teachers once insisted that if you drank a glass of mercury and waited, you could piss it out. Urban legend or amazing feat? You decide. My biology teacher, however, when enlightened to this potential crowd pleaser, pointed out that real trick would be to survive such a foolhardy stunt.
Mercury is not nice stuff. Airborne mercury is highly toxic when inhaled and metallic mercury found in thermometers slowly evaporates when exposed to the air. A room’s atmosphere can reach contamination levels from the presence of just small amounts of spilled mercury.
This airborne threat is of minor concern, however, compared with the presence of organic mercury compounds such as methylmercury. Exposure to very small amounts of these compounds can result in devastating neurological damage and death. When mercury enters bodies of water, biological processes transform it to methylmercury. Fish then absorb methylmercury from their food and directly from water as it passes over their gills. Hence most people are exposed to mercury by eating fish. Since mercury is tightly bound to proteins in all fish tissue, including muscle, there is no method of cooking or cleaning them that will reduce the amount of mercury in a meal! So, given time, mercury released into nature could potentially end up on your dinner plate.
From the mid-1950s to the 1970s, several mass poisonings took place in Japan and in Canada as a result of consumption of fish from waters contaminated by methylmercury. In the U.S., while such high profile health scares have yet to occur, the number of states that have issued health advisories limiting consumption of fish has risen steadily from 27 states in 1993 to 43 states in 2004.
Currently, scientific concern is focused on the health impacts of chronic exposures to low levels of mercury from dietary sources. Preliminary estimates of mercury levels in hair and blood samples from the 1999 National Health and Nutrition Examination Survey suggest that approximately 10% of women have mercury levels within one tenth of potentially hazardous levels.
For fetuses, infants and children, the primary health effects of mercury are on neurological development. Even low levels of mercury exposure, such as an expectant mother\\\’s consumption of methylmercury in dietary sources, can adversely affect the brain and nervous system to the extent that pregnant women may be advised to avoid fish altogether. Such advice is backed up by the National Research Council (NRC), which issued a report estimating that as many as 60,000 newborns a year in the U.S. are now at risk for adverse neurodevelopmental effects from dietary mercury. Pretty remarkable that fish consumption could have such potentially devastating effects on the rest of an unborn child\\\’s life.
While some treatments are possible for processing water, there is no way of filtering out the mercury that ultimately ends up on human dinner plates. There seems to be only one solution, and that is to prevent mercury from ever entering the biosphere.
Electric utility smokestacks are by far the largest source of mercury emissions in the United States. Unfortunately, the proposed mercury-reduction plan recently put forth by the Bush-led Environmental Protection Agency simply does not do enough. While the Clean Air Act mandates a 90% reduction in mercury emissions from power plants, the current proposal will put off any serious cuts until 2018. So instead of protecting communities from mercury now, the proposal allows for at least fourteen more years of dangerous exposure.
There are also talks of forming a mercury cap and trade system, but this is impractical for such a toxic substance. Under said system, some places will continue to emit as much or more mercury than they historically have, putting the surrounding human and wildlife populations at continued high levels of risk. And, judging from the past decisions of the current pro-industry administration, we can expect that the caps will be placed at more or less meaninglessly high levels.
The comment period on the new EPA proposal for weakened mercury emission standards lasts until April 30, so we have until then to let them know what we think. To edit and submit a letter, go to www.environmentaldefense.org, click on the link for the “Action Center”, and then look up the mercury issue.
And, to return to that eye-catching party trick, don’t piss on what you’re going to eat.