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Toxic metals

Toxic metals

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Which of the following metals can be harmful to the environment and living organisms?

Toxic metals

Jenny, Esi and Aki, have just finished their band practice. This went well didn’t it? Yeah! I was thinking… Maybe we should change the name from “In charge” to something different. What about “Toxic metals”?

Toxic metals? No way! I don’t want to be associated with toxic materials! Not all metals are bad for us and the environment. Our bodies need some metals to work properly, like zinc, copper and iron.

Others, like mercury, lead and cadmium, can cause a lot of harm to the environment and to living organisms. We call these toxic metals, or sometimes toxic heavy metals. Let’s take a closer look at some of them. Mercury is the only metal that exists in liquid form at room temperature. Although the use of mercury in household items is prohibited nowadays, it was commonly used for certain types of batteries, in thermometers and in dental fillings.

Despite its many uses, handling mercury is dangerous, and its vapours are particularly toxic. Even exposure as short as one day can cause health problems like nausea and diarrhoea. Long-term exposure can lead to much more serious issues, like kidney disease or nervous system disorders. When mercury enters the environment, sooner or later it ends up in rivers and lakes. There, it usually ends up in organisms, such as fish.

This makes fish in many places unsuitable for eating. But sometimes people don’t know that a lake or a river has been polluted with mercury, so they fish there anyway, and get mercury poisoning through food. Another example is cadmium, and cadmium compounds. Cadmium is used to protect objects from rusting. It’s sometimes also found in certain chemicals used for farming, fertilisers.

When cadmium is present in the soil, plants absorb it. This is a problem especially in farmed areas, and areas with a lot of animal and plant life. People and animals who eat plants with high levels of cadmium, especially for long periods of time, can get cadmium poisoning. This is because cadmium that enters the body, stays in the body, and so the amount of it in the body increases over time. Cadmium poisoning can cause lung disease and soft bones.

Lead is a soft, toxic heavy metal. It’s mostly used in car batteries, but also as radiation protection in medicine and dental care. Lead pipes were once used to carry water, but most countries have rules against that now. If water flows through pipes containing lead, it becomes polluted with the toxic material. In some countries, not all lead pipes have been replaced.

In these countries, lead poisoning is still common. Exposure to lead, especially when people eat or drink it, can cause nausea, kidney disease, brain disease or paralysis. And just like cadmium, lead stays in the body for a long time. Right, I see. Maybe that’s not such a good name after all...

Exactly!