Heavy metals in the terms we view them as environmentalists are characterized by their capacity to do harm through toxicity. Heavy metals are commonly used in medical tools and are essential to our technological era due to their versatility and conductive attributes. Without Chromium, Lead, Mercury, and Cadmium many of the implements we use in our everyday lives would be obsolete or much less efficient. But because of their increasing use in technology more and more waste containing these heavy metals is drained into the environment.
The heavy metal that I will focus on today is Mercury (Hg) a metal that has been used by humans for over a millennia. Initially Mercury was studied for its distinct physical properties, being liquid at normal temperatures it was used for alchemy in ancient times. During these experiments the toxic side of Hg was discovered. Even in low doses Mercury can cause damage to the brain, kidneys and lungs. In the modern age we use Mercury in mining, thermometers, and dental implants; using its distinct physical properties to our advantage under strict regulations. But even with all the regulations on mercury content and purity there is still a high degree of bioaccumulation of Mercury in wildlife; particularly in fish.
This bioaccumulation in fish is due in part to human contamination from medical waste, but as highlighted in xinleichen’s ponder article there is also a high amount of Mercury being released from environmental sinks in polar regions due to global warming. In the arctic permafrost alone there is “ 32 million gallons worth of mercury, or the equivalent of 50 Olympic swimming pools.” The article provides a little context for this by stating that in the sources that they found alone it was double the amount of Mercury that in the oceans as a whole. This means that if this were to enter the environment than the amount of fish that is safe for human consumption would drop 3 fold.
In essence according to this chart, if global warming continues and the Mercury is released from the permafrost one of the major food sources for humans (the ocean) would only be able to provide 1, 4 ounce serving of anchovies or an equivalent mercury source per week for a non-pregnant adult. If anybody were to eat more than this they would see signs of mercury poisoning and adverse health effects very quickly.
In summary, even though heavy metals are very useful in small doses in our technological age, the environmental sinks of mercury that are being effected by global warming could cause a major shift in the diet of much of the population of the earth.