Shining a light on mercury

Mercury
Mercury isnasty. It’s a nerve toxin. It can cause permanent brain damage, weaken immune systems, impair memory, and damage the kidneys and liver. Children are especially susceptible.

What’s more, mercurycanaccumulate in a fetus at levelshigherthan in a mother’s body. Herchildmaybebornretarded, blind, or deaf. Or itmaybeleftwith a short attention span, poormotor reflexes, or an inability to copewithlanguage.

 

But mercuryisalsocommerciallybewitching. It’s the onlymetalthat’sliquid at room temperature. So it’sideal for electrical switches activated by tilting.

 

It expands or contractsevenlywhentemperatures change, and thatmakesitsuitable for thermostats for ovens and furnaces.

 

It’s an effective pesticide, fungicide, and preservative. And becauseit’sso effective in killingorganisms, and becauseit combines easilywithothermetals, it has been used in an amalgam to repairteeth. It fillsholeswhilecontinuing to fightenamel-eatingbacteria.

 

In addition, and here’swhere I slapmyforehead in exasperation, it’salsoused in fluorescent lighting. My ignorance sometimesknows no bounds. Over the pasttenyears, we have replacedour incandescent light bulbs with compact fluorescents. Theyrequireonly a quarter of the electricity to produce the same light.

 

Whatmakesmercury indispensable for fluorescent lightingisitsvolatility. It vaporizeseasily. And when an electric arc ispassedthrough a fluorescent tube, the mercuryvapouremits ultraviolet light that, in turn, makes the phosphorouscoatinginside the tube glow.

 

There are more than 13 tonnes of mercury on the roads in Canada in cars and trucks, governingeverythingfrom light switches, to instrument panels, to antilockbrakes. Even the new, high intensityheadlightscontainmercuryvapour.

 

One of the major problemswe face ismercuryemissions. Whenvehicles are scrapped and melted down in recycling, all of the mercurytheycontainisprobablyreleased to the environment.

 

Once there, itcan hop and skip anywhere in the world — vaporizing, floatingalongwithbreezes for up to 30 days, condensing and falling, and vaporizingagain. It getstransformed by bacteriaintomethylmercury, whichcanbetaken up in plants and enter the foodchain.

 

At everystep up the chain, itaccumulates, so by the time itgetsto us in fish or higheranimals, it’shighlyconcentrated.

 

Aftermuch soul searching, I’vedecidedthatswitching to compact fluorescents in our home was the right thing to do, eventhough I wasunaware of theirmercury content.

 

Coal-firedelectricitygenerating stations are, far and away, the biggest source of mercury pollution, socutting down on the amount of electricitywe use is the biggest contribution wecan to reducingmercury in the environment. Also, whenwebuyanother car, it’sgoing to bemercury free and fuel efficient. Except for the new headlights, mercury has been banned in European cars since the early 1990s.

 

Under currentregulations, compact fluorescents canbe sent to landfillsaftertheyburn out, becausetheycontainsolittlemercury.

 

But even a littleistoomuch. Toronto helpskeepthem out of landfills by accepting  them as hazardouswaste and sendingthem for recycling. Askyour local worksdepartment if itwill, too.

 

If itdoes, youcanfeel more comfortable in the battleagainstcoal-firedgenerating stations.

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