Published on April 27th, 2013 | by Joe Starks0
Know Your Substances: Heavy Metals
It is quite common in our days to hear about heavy metals polluting our waters, killing off marine populations and how dangerous a thermometer can be if it breaks. We think of heavy metals as something extremely dangerous that surrounds us and tries to find a way to get into us and kill us. But is that really true? What are heavy metals and how dangerous are they really? Do they have any use? How do you avoid them?
What are Heavy Metals?
In chemistry, heavy metals are metallic elements that have a high density. Almost all heavy metals are poisonous to humans in low concentrations. A few selected elements are needed in traces by the body for it to function properly. Many heavy metals can be deadly if they reach a sufficient concentration within our bodies. There are heavy metals like cadmium that are usually dangerous, but under certain circumstances might become beneficial for the body.
What is their use?
Heavy metals are plentiful in nature, some more than others. Iron for instance is a heavy metal as is lead. We all know that our body needs a little bit of iron to be able to create red blood cells (it is needed for a component of red blood cells and other cells). A list of the heavy metals our body needs in a small trace amount is this:
- Iron, which we need to create iron-containing proteins. Hemoglobin gives the red blood cells their color and need iron to be formed.
- Cobalt, is a key component of vitamin B 12 known also as cobalamine. People deficient in cobalamine get nervous system problems and can give birth to children with nervous problems.
- Manganese is contained in many enzymes, which are essential for the body’s correct function.
- Molybdenum is important for the body because it must exist at the active sites of some enzymes for them to function properly.
- Zinc, is found in 100 specific enzymes and is vital for life to exist.
Getting too much of any of these elements is very dangerous, so the best sources are always normal food items, which contain these heavy metals in the correct, small amounts. Supplementing these heavy metals can be quite dangerous and should only be done after a physician’s request.
Aside from our biological needs for heavy metals they have helped us create civilizations as we know it. This is why some stages of our civilizations progress were named after the heavy metals used mostly during the period. For instance the Bronze Age and the Iron Age are such periods of human history.
The chemical properties of some heavy metals also have benefited humanity as a whole, for instance the ability of mercury to expand in heat and grow smaller in cold helped us create the typical thermometer. We could not build durable cars, ships, building and so much more without heavy metals.
Lead, which is extremely poisonous to humans if ingested, has also saved thousands of lives by protecting people from radiation. Radiation cannot pass through lead’s extremely dense molecular structure, making it an ideal insulation for x-ray rooms and bunkers.
On the downside, heavy metals are known to pollute our water sources because they easily sink into the ground and find the water table. Also factories that have heavy metal byproducts often dump them in the sea. The devastating result is that many whales and dolphins have a toxic amount of mercury in their flesh (smaller fish don’t live as long usually to get a high amount and they don’t consume as much through other fish). If the meat of a mercury infused sea creature is consumed by a human it is dangerous for that individual’s health. Like most poisonous substances the more you consume the worse the consequences will be.
While heavy metals have helped our civilization develop to what it is today and they save countless lives with their chemical properties, they can also be deadly for marine life and those unfortunate humans who consume them. Some heavy metals are absolutely essential for life to exist when they are taken in trace amounts. Heavy metals have their place in industry and some of them in diet, but they should be handled with care as not to ruin the environment.