B. Bioaccumulation
An important process through which chemicals can affect living organisms is bioaccumulation. Bioaccumulation means an increase in the concentration of a
chemical in a biological organism over time, compared to the chemicals concentration in the environment. Compounds accumulate in living things any
time they are taken up and stored faster than they are broken down metabolized or excreted. Understanding the dynamic process of
bioaccumulation is very important in protecting human beings and other organisms from the adverse effects of chemical exposure, and it has become a
critical consideration in the regulation of chemicals Extension Toxicology Network, 1993. Bioaccumulation is a process where chemicals are retained in
fatty body tissue and increase in concentration over time.
http:www.epa.govpesticidesglossary .
Bioaccumulation refers to how pollutants enter a food chain; is increase in concentration of a pollutant from the
environment to the first organism in a food chain. The accumulation of a chemical in tissues of an organism to levels greater than in the surrounding
medium. Accumulation may take place by breathing, swallowing or dermal contact Marietta College, 2006.
Bioaccumulation is a general term for the accumulation of substances, such as pesticides DDT is an example, methylmercury, or other organic
chemicals in an organism or part of an organism. The accumulation process involves the biological sequestering of substances that enter the organism
through respiration, food intake, epidermal skin contact with the substance, andor other means. The sequestering results in the organism having a higher
concentration of the substance than the concentration in the organism’s surrounding environment. The level at which a given substance is
bioaccumulated depends on the rate of uptake, the mode of uptake through the gills of a fish, ingested along with food, contact with epidermis skin, how
quickly the substance is eliminated from the organism, transformation of the substance by metabolic processes, the lipid fat content of the organism, the
hydrophobicity of the substance, environmental factors, and other biological and physical factors. As a general rule the more hydrophobic a substance is the more
likely it is to bioaccumulate in organisms, such as fish. http:en.wikipedia.orgwikiTalk.
Universitas Sumatera Utara
Bioaccumulation is the term bioaccumulation refers to the net accumulation over time of metals [or other persistent substances] within an
organism from both biotic other organisms and abiotic soil, air, and water sources Fig. 3.
http:www.greenfacts.orgglossaryabcbioaccumulation- bioaccumulate.htm
Source: Wisconsin Department of Natural Resources http:www.greenfacts.orgglossaryabcbioaccumulation-
bioaccumulate.htm Fig. 3. An example of the Bioaccumulation
C. Bioconcentration
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