Mercury is one of the substances we often hear about, especially when it comes to the dangers it poses, but we might have many questions on what it actually is, how to prevent exposures and what its effects might be otherwise.
If you find yourself wishing you would know more about the subject, in this article you’ll learn many useful things and, therefore, you’ll know how to tackle this issue and prevent any exposure in order to live a healthier life.
How it gets released
Before going into the details of its effects, let’s take a moment and talk about what mercury actually is and where you can find it.
First of all, mercury is an element that occurs naturally and can be found in every kind of medium: air, water, and soil. It normally occurs in the earth’s crust and it gets released into the environment through volcanic activity.
Of course, another significant cause of its release into the environment is the human activity. Unfortunately, here as well we have a significant impact through the coal-fired power stations we operate on a global level.
Other sources include residential coal burning for heating and household activities, industrial processes, waste incinerators, as well as mining for various metals such as gold.
Types of mercury
This substance that’s liquid at room temperature exists in various forms, so let’s take a look at each of these in order to better understand what the risks are.
Elemental (or metallic) mercury is the liquid substance that we all picture when we think about it. In the atmosphere, most mercury is found in elemental form, but the trick is that it’s a gas rather than a liquid.
Methylmercury is the one you should stay away from as much as possible since it’s the toxic form of mercury found in fish, but more on that a little further in this article. There’s also inorganic mercury to which people are exposed through their occupation.
All of these forms have different degrees of toxicity and effects on the human body.
How methylmercury is formed
The story is pretty simple. Once mercury is released into the environment, it can be transformed into methylmercury by bacteria. This resulting substance then bioaccumulates in fish and shellfish. Bioaccumulation means that an organism has higher concentrations of a certain substance than its surroundings.
As if this would not be enough, a secondary process takes place at the same time, which is biomagnification. Large predatory fish are more likely to contain high levels of mercury since they eat smaller fish that have also acquired mercury through the ingestion of plankton.
Exposure to mercury
On some level, all humans are exposed to mercury, although these levels are rather low. However, in some cases, when the levels are very high, problems start to arise. There are two general groups of people who are sensitive to mercury exposure and in these cases, special measure should be taken.
Fetuses are most susceptible to developmental issues if exposed. The presence of methylmercury in the womb can be a result of the mother’s consumption of seafood. This can have a negative impact on the baby’s nervous system and brain.
Given that the primary health effect of this exposure is an impaired neurological development, things such as memory, attention, language, cognitive thinking, motor skills might be affected in those children who were exposed to the substance as fetuses.
The second group is formed by people who are regularly exposed (which is defined as chronic exposure) to high levels of the element. Populations that rely on subsistence fishing and those who are occupationally exposed are prone to be a part of this group.
In populations such as China, Brazil, Canada, Columbia or Greenland, between 1.5/1000 and 17/1000 children showed developmental issues caused by eating fish that contained mercury.
Exposure effect on humans and animals
Mercury is not useful to the human body, so you can at best think about it as poison. Its effects vary depending on a number of factors such as age, duration and form of exposure, and level of toxicity. When it enters the body, mercury is stored in the kidneys, blood, spleen, liver, brain and even bones.
Elemental mercury and methylmercury are toxic to the central nervous system, as well as to the peripheral one. Inhaling it is the worst type of exposure, as it’s quickly absorbed through the lungs and heads towards the organs, leading to effects on the immune, digestive and nervous systems, as well as on lungs and kidneys.
After exposure, whether it’s through inhalation, ingestion or contact with the skin, neurological and behavioral disorders could be observed, including insomnia, tremors, memory loss, headaches or cognitive and motor dysfunctions.
Of course, besides the effects on the human body, the mercury released in the environment has an impact on animals as well. The most prone ones are those that eat other fish-eating animals. Harmful effects can include reduced reproduction, slower development, abnormal behavior or even death.
Besides the measures that should be taken on a global level, there are some things that you can do right away in order to reduce the potential exposure risks you might be facing.
Take a look around your house and if there’s an older version of an underarm thermometer containing mercury, make sure that it is safely stored without running the risk of being broken. Especially if you have children, you should use a digital thermometer for babies and keep everything safe.
If you are pregnant and want to make sure that your baby is protected, avoid eating too much fish and shellfish, especially those species that have been identified as prone to contain high levels of methylmercury. As a rule of thumb, bigger fish, such as marlin, shark, tuna or swordfish, are to be avoided.
Even as the child is in his or her early years, you should be careful and not include too often in the diet those species of fish marked as potentially risky. Keep in mind that children exposed to mercury are particularly sensitive because the ratio between food, water, and air intake and individual body weight is much higher compared to adults.