Toxic Effects of Mercury
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Toxic Effects of Mercury
Pollution is the process by which contaminants are added into an environment leading to adverse changes (Gifford 2006). The contaminants that cause pollution can range from foreign materials like unwanted energy to naturally occurring pollutants such as dust particles and pollen. Pollutants can be analyzed on the criteria of severity using three factors. These factors include its chemical composition, its concentration and its persistence against eradication from the environment (Rao 2006). An example of a severe pollutant is mercury. Mercury is a toxic chemical element with the symbol (Hg) and it is well known for its contribution to the pollution of air, water and soil.
Exposure of mercury or its chemical compounds to the human body is very harmful and the consequences are death threatening. Mercury poisoning also known as mercurialism is the disease that develops from the exposure to this toxic element (Goel 2006). Mercurialism often leads to damaging of the body organs such as the kidney, the brain and the lungs. Mercury poisoning can also result to several disease like the neurological syndrome called Minamata disease. Other mercury related diseases include the pink disease and the Hunter-Russell syndrome. Mercury poisoning is usually detectable through the observation of symptoms. The symptoms include lack of coordination in the victim, impairment of the victim’s senses and the presence of a disturbed sensation in the victim.
Mercury plays a major role in the pollution of the environment. An illustration of its pollution of the environment is its negative influence on the nitrogen cycle (Rao 2006). If mercury is introduced into the soil composition through human activities such as burning fossil fuels and industrial pollution, the numbers of ammonia-oxidizing bacteria decreases (Pirrone 2005). The ammonia-oxidizing bacteria are usually responsible for the nitrification process and their decline means that the nitrogen cycle will be significantly interrupted. Another effect of mercury to the environment is the chronic toxicity of the aquatic life. This effect can be extrapolated into other ecosystems by the consumption of contaminated fish by humans, birds and land animals.
Mercury may enter an ecosystem food web by the aid of two processes namely bioaccumulation and biomagnifications. Bioaccumulation is defined as the process by which metals accumulate within an organism from both biotic and abiotic sources (Goel 2006). Biomagnifications on the other hand describes the process by which heavy metals progressively builds up as one moves from one trophic level to the next higher trophic level. An example can be drawn from the aquatic food web. In this food web, bioaccumulation of mercury compounds such as methyl mercury takes place in the fish overtime because of the strong covalent bonds between methyl mercury in fish tissues and the protein sulfhydryl groups (Gifford 2006). This bond increases the half-life of the elimination process enabling the transfer of mercury to top-level fish eating species in the food web such as the humans and eagles.
The major bio-geo-chemical nutrient cycle that mercury encounters on its journey to being absorbed by biological organisms is the hydrological cycle (Goel 2006). The mercury cycle is entirely dependent on the aquatic ecosystem. Mercury is first deposited in the aquatic ecosystem from the atmosphere through rainfall. Once in the water, it enters a complex cycle in which it can take different forms. The mercury is then deposited on the sediments by settling particles and then later released by diffusion into a food chain. In conclusion, mercury also has advantageous applications aside from it being a major contaminant in pollution of the environment. For instance, it is used in the field of science in the construction of thermometers, barometers and manometers.
References
Gifford, C. (2006). Pollution. Chicago, Ill: Heinemann Library.
Goel, P. K. (2006). Water pollution: Causes, effects and control. New Delhi: New Age International.
Pirrone, N. (2005). Dynamics of mercury pollution on regional and global scales: Atmospheric processes and human exposures around the world. New York: Springer.
Rao, C. S. (2006). Environmental pollution control engineering. New Delhi: New Age International.