What Is Biomagnification?
Biomagnification occurs when substances, such as chemicals or heavy metals, concentrate within the internal organs and tissues of living beings. It is sometimes referred to as bioamplification or biological magnification. It can affect all animals, including humans, although toxins tend to be more concentrated at higher levels of the food chain.
Biomagnification happens in areas with contaminated water, food, and air sources. Animals absorb toxins in their natural surroundings by eating, breathing, and drinking. Predators then eat large quantities of these contaminated species, allowing the toxins to be further concentrated within their bodies. One example of biomagnification is seen with tuna fish. Tuna fish feed on mercury-laden zooplankton in the ocean. Because they eat large quantities of zooplankton, the mercury concentrates at high levels within the tunas’ body. When humans eat these mercury-contaminated tuna, they are exposed to even higher concentrations of mercury, which explains the recommendation that humans control their consumption of tuna.
Substances That Contributes To Biomagnification
Persistent organic pollutants contribute to biomagnification. These pollutants are substances which are not easily broken down in the environment. Some persistent organic pollutants occur naturally, but others are man-made, such as the chemicals used in pharmaceutical, pesticide, industrial, and solvent manufacturing. Additionally, ocean mining activities are responsible for releasing heavy metals and toxins into the water. One of the reasons that these pollutants cannot be degraded in the environment is that plants and animals have not yet been exposed to them for a long period of time. This means they have not had enough time to evolve the appropriate biological methods for detoxification and elimination.
Metals are another substance that contribute to biomagnification. Most living organisms are able to excrete metals from their systems. Unfortunately, in some cases, the concentration of metals in the environment is too high for organisms and they cannot be eliminated from the body quickly enough to prevent permanent damage.
Processes Of Biomagnification
There are several biomagnification processes, including: bioaccumulation, biodilution, and bioconcentration. Bioaccumulation occurs within a specific level of the food chain, or trophic level. It involves the concentration of toxins in specific organs within a particular species. Bioconcentration occurs when the toxin comes only from a source of water. Biodilution is similar to both bioaccumulation and bioconcentration in that it occurs across a specific level of the food chain and only affects species living in bodies of water. Additionally, biodilution is the opposite of biomagnification, meaning that the concentration of toxins becomes diluted as it moves to higher levels of the food chain.
Health Impacts Of Biomagnification
Because humans are at the top of the food chain, biomagnification is of serious concern. Humans who are affected by biomagnification tend to have a higher risk of developing certain cancers, liver failure, birth defects, brain damage, and heart disease. The toxins responsible for these health problems include: mercury, lead, chromium, cobalt, and cadmium. Biomagnification is also responsible for disrupting the interconnectivity of the food chain by making predators more susceptible to disease and in some cases, death. Some studies, however, have determined that biomagnification is not as common as previously believed. Despite this information, certain chemicals have been proven to biomagnify in the environment, including: DDT, mercury, arsenic, PCB’s, and DDE.