Dictionary > BIOACCUMULATION

BIOACCUMULATION

Bioaccumulation
– 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, and/or 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. Another way of saying this is that bIOACCUMULATION of a substance is correlated to the octanol-water partition coefficient (KOW) of the substance. Increasing hydrophobicity (lipophilicity) leads to an increasing propensity to bioaccumulate. Some substances do not conform to this relationship, such as methlymercury. Methlymercury accumulates in fish to a much greater degree than methlymercury’s KOW would indicate.
A related term is bioconcentration. Bioconcentration differs from bIOACCUMULATION because it refers only to the uptake of substances into the organism from water alone. Bioaccumlation is the more general term because it includes all means of uptake into the organism.
source: http://toxics.usgs.gov


You will also like...

Stem
Stems

Stems primarily provide plants structural support. This tutorial includes lectures on the external form of a woody twig ..

genes controlling growth and development
Control of Growth & Development

Control of Growth & Development tutorials look at how the genetic makeup determines the biological processes on a da..

"Opabinia regalis"
The Evolutionary Development of Multicellular Organisms

Multicellular organisms evolved. The first ones were likely in the form of sponges. Multicellularity led to the evolutio..

Lights' Effect on Growth
Lights’ Effect on Growth

This tutorial elaborates on the effect of light on plant growth. It describes how different plants require different amo..

squirrel
Animal Water Regulation

Animals adapt to their environment in aspects of anatomy, physiology, and behavior. This tutorial will help you understa..

The process of photosynthesis
Photosynthesis – Photolysis and Carbon Fixation

Photosynthesis is the process that plants undertake to create organic materials from carbon dioxide and water, with the ..

Related Articles...

No related articles found

See all Related Topics