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 BioaccumulationDDT, 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.
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 readingThe tendency of chemicals to become more concentrated as they move up the food chain is known
by killing organisms
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.
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.
DDT is dichlorodiphenyltrichlorethane; biomagnification of DDT in some organisms is possible.
These effects are known as biomagnification and bioaccumulation which leads to cause different type of diseases
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Biomagnification of pesticides basically means that the concentration of the substance exceeds what it should be. This makes the pesticide more powerful and harmful.
The easiest way to prevent biomagnification would be to cut down or better yet eliminate our pollutants so they cant transfer.
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.
Mercury levels would be highest at the top of the food chain due to biomagnification.
The tendency of chemicals to become more concentrated as they move up the food chain is known
Decrease reliance on harmful pesticides.
by killing organisms
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.
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.
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.