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Biomonitoring. Source: NIEHS

Introduction Bioaccumulation is a process resulting in the concentration of substances in living tissues. The term is used often in reference to such chemical contaminants that may do harm to organisms as chlorinated pesticides and heavy metals. Nonetheless, organisms do accumulate chemicals and minerals needed for their survival-this may be referred to as bioaccumulation. Many substances entering organisms are eventually eliminated in wastes; whereas such others as heavy metals and fat-soluble organic substances (for example, persistent organic pollutants or POPs) may remain in the body for long periods of time. The U.S. Environmental Protection Agency uses the term persistent, bioaccumulative and toxic pollutants (PBTs) to categorize substances that raise human health and environmental health concerns. Depending on their affinity for fatty tissue and the length of the body's exposure, PBTs may accumulate in high concentrations and may cause physiological problems. PBTs enter the organism through a variety of active and passive means, including respiration, food intake, and epidermal (or skin) contact.

Types of Bioaccumulation
  • Organismal - Compounds present in an organism's environment may concentrate in the body over time. For example, fish that swim frequently in contaminated water may build up pollutants in their fatty tissues. This type of accumulation, in organisms experiencing continuous environmental exposure, is linear.
  • Trophic transfer - Here, fat-soluble compounds pass from prey to predator. The more prey that are eaten, the greater the magnification of the compound as it travels up the food chain. Such organisms at the top of the food chain as humans or polar bears, can receive the highest concentrations. This process is sometimes referred to as biomagnification, since the concentration of pollutant in the predator is a large multiple of that measured in the prey.
  • Soil Bioaccumulation - PBTs that are dumped into surrounding environments from specific waste sites or that leak from specific factories are point-source pollutants. Often, the substances bind to soil particles and persist until they are removed through erosion, water percolation, or uptake by plants, microorganisms or animals in soils or sediments. This process includes both linear accumulation through abiotic processes, and biomagnification-as pollutant-laden bacteria and fungi are consumed by earthworms and other detritivores (or detritus eaters). Often, soil bioaccumulation is the initial source of PBT exposure for terrestrial organisms. Such methods as phytoremediation (using plants to remediate) and mycoremediation (using fungi to remediate) have proven useful in removing or even breaking down pollutants in soil, and could be increasingly important solutions in the future.
ExamplesChlorinated pesticides

DDT, a chlorinated pesticide used heavily on U.S. farms in the middle of the 20th century, was found to bioaccumulate through earthworms to organisms higher on the food chain. Various Songbirds, waterbirds and Birds of Prey experienced drastic population decreases during the 1950s due to such severe reproductive problems as overly thin, breakable eggshells. These problems were associated with widespread spraying of DDT. Writer and biologist Rachel Carson affected U.S. policy and public perception regarding pesticides greatly by describing the devastating effects of DDT in her 1962 best-selling book, Silent Spring.

Heavy metals

A study of bioaccumulation in cyprinid fish of the Kor River in Iran found high levels of Mercury in the fishes' muscles, liver, kidneys, brain, and gonadal tissue. One species was sampled in three river stretches: the Upper, Central, and Lower Kor, and the monitored fish proved to have significantly higher mercury contamination in the middle reach of the river where two cities (Shiraz, Marvdasht) produced industrial metals.

In Japan during the 1950s, strange cases of human neurological disorders and death began to appear in Minamata City and other industrial areas. The "Minamata Disease" was traced to fish and shellfish that contained high levels of methylmercury, and that had been eaten by local townspeople. The methylmercury was traced to the Chisso Corporation's Minamata factory, the largest Japanese producer of acetaldehyde (a chemical used in manufacturing plastics) during the 1950s. Methylmercury is formed during the production of acetaldehyde, and the factory had been discharging a large amount of methylmercury via wastewater directly into the Yatsushiro Sea. People who ate a lot of the contaminated fish over a long period of time were especially at risk for Minamata Disease.

Synthetic industrial compounds

Polychlorinated biphenyls, or PCBs, are synthetic chemical substances used in a large number of mechanical and electrical systems because of their high thermal and chemical resistance. They do not break down easily-remaining in the environment for long periods of time and that build up as inputs continue. Exposure to, and the consequent bioaccumulation of, PCBs has been associated with cancer in animals, as well as negative effects to the immune, reproductive, nervous and endocrine systems. When PCBs are disposed of through incineration, dioxins are formed-another type of bioaccumulated compound that has shown extremely disconcerting long-term effects on the human body. The result of PCB and dioxin bioaccumulation has revealed itself in the fat of polar bears and in human breast milk of Inuit women, sometimes at toxic levels.

Related terms: bioconcentration, biomagnification, biotransformation, biomonitoring

Further reading
  • Carson, Rachel. Silent Spring. New York: Houghton Mifflin Co, 1962.
  • Johansen, Bruce E. 2002. The Inuit's struggle with dioxins and other organic pollutants. The American Indian Quarterly 26(3): 479-490.[link to http://muse.jhu.edu/journals/american_indian_quarterly/v026/26.3johansen.pdf]
  • Kinney, C.A., E.T. Furlong, D.W. Kolpin, M.R. Burkhardt, S.D. Zaugg, S.L. Werner, J.P. Bossio, & M.J. Benotti. 2008. Bioaccumulation of pharmaceuticals and other anthropogenic waste indicators in earthworms from agricultural soil amended with biosolid or swine manure. Environ. Sci. Technol. 42(6):1863-70.
  • National Institute of Minamata Disease, Japan Ministry of the Environment [link to http://www.nimd.go.jp/english/]
  • Taherianfard, M., M. Ebrahimi & S. Soodbakhsh. 2008. Bioaccumulation of Mercury in Fishes of Kor River. Australian Journal of Basic and Applied Sciences 2(4): 904-908. [link to http://insipub.net/ajbas/2008/904-908.pdf]
  • World Health Organization, "Dioxins and their effect on human health" [link tohttp://www.who.int/mediacentre/factsheets/fs225/en/index.html]
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Continue Learning about Natural Sciences

The process by which non-biodegradable pollutants become more concentrated near the top of a food chain is called?

The tendency of chemicals to become more concentrated as they move up the food chain is known


How can biomagnification affect tertiary levels?

by killing organisms


How does the biomagnification phyramid compare with the energy phyramid?

The biomagnification pyramid shows the concentration of toxins increasing as you move up the food chain, where predators accumulate toxins from their prey. In contrast, the energy pyramid illustrates the flow of energy through trophic levels, with energy decreasing at higher levels due to energy loss as heat from metabolism. Both pyramids highlight different aspects of ecosystems: biomagnification emphasizes toxin accumulation, while the energy pyramid demonstrates energy transfer.


Which metal contribute to biomagnification be a problem in ecosystems?

Mercury is a metal that can contribute to biomagnification and be a problem in ecosystems. It is released into the environment through industrial activities and can accumulate in organisms, particularly in fish. As predators consume smaller prey, the concentration of mercury in their bodies increases, leading to biomagnification. Mercury can have toxic effects on organisms and can disrupt their reproductive, neurological, and immune systems.


What is DDT and what does it have to do with bio magnification?

DDT is dichlorodiphenyltrichlorethane; biomagnification of DDT in some organisms is possible.

Related Questions

What are some of the effects that agricultural chemicals have on animals?

These effects are known as biomagnification and bioaccumulation which leads to cause different type of diseases


Is organic cultivation a solution to biomagnification?

no


What is biomagnification of pesticides?

Biomagnification of pesticides basically means that the concentration of the substance exceeds what it should be. This makes the pesticide more powerful and harmful.


How do you prevent biomagnification?

The easiest way to prevent biomagnification would be to cut down or better yet eliminate our pollutants so they cant transfer.


How to prevent biomagnification?

Biomagnification is the increase in pollutants from the environment from one consumer to the next. To avoid this, educate yourself on the diet and living conditions of the food you are eating.


In the food chain, where would mercury levels be highest as a result of biomagnification?

Mercury levels would be highest at the top of the food chain due to biomagnification.


The process by which non-biodegradable pollutants become more concentrated near the top of a food chain is called?

The tendency of chemicals to become more concentrated as they move up the food chain is known


How can you stop biomagnification?

Decrease reliance on harmful pesticides.


How can biomagnification affect tertiary levels?

by killing organisms


How does the biomagnification phyramid compare with the energy phyramid?

The biomagnification pyramid shows the concentration of toxins increasing as you move up the food chain, where predators accumulate toxins from their prey. In contrast, the energy pyramid illustrates the flow of energy through trophic levels, with energy decreasing at higher levels due to energy loss as heat from metabolism. Both pyramids highlight different aspects of ecosystems: biomagnification emphasizes toxin accumulation, while the energy pyramid demonstrates energy transfer.


Why biomagnification is important?

Biomagnification is important because it can lead to higher concentrations of harmful substances in organisms higher up the food chain. This poses a risk to top predators and can have detrimental effects on ecosystems. Monitoring biomagnification helps us understand how pollutants move through food webs and can inform conservation efforts.


Why can't you have biomagnification with bioaccumulation?

Biomagnification and bioaccumulation are related but distinct processes. Bioaccumulation refers to the accumulation of substances, such as toxins, in an organism over time, primarily through its diet and environment. Biomagnification, on the other hand, occurs when these toxins become increasingly concentrated as they move up the food chain. Therefore, you can have bioaccumulation in individual organisms, but for biomagnification to occur, there must be a transfer of accumulated toxins from one trophic level to another, leading to higher concentrations in predators.