Bio-accumulation and Bio-magnification
Few toxic substances especially non- biodegradable (which cannot be metabolized by the living organism) ones, often present in the industrial waste have the ability to move through the various trophic level. Higher concentration of these elements in the food chain creates a lot of serious problems and may even cause life-threatening diseases like cancer. The process of movement of toxic elements is of two type Bio-accumulation and Bio-magnification.
- It is the process of increase in the concentration of toxic elements within the body of particular organism (i.e. it refers to how an element first made an entry into the food chain) and in general the concentration of such pollutants become higher in the body of the organism compared to the external environment like air, water etc.
- Moreover, this accumulation will grow until it leads the organism to a deadly situation.
- Example- The air pollution which is caused due to various factors including the vehicular emission, progresses to an accumulation of toxic elements like PM2.5 and PM10 inside an organism and can have dangerous impacts on humans as well as other organisms.
- Biomagnification is also known as bio amplification, in this the concentration of the toxicants increases at the successive trophic levels. It is due to the reason that toxic elements cannot be absorbed and simultaneously they get transferred to the successive higher trophic levels resulting in more concentration of toxicants at the higher trophic level.
- Biomagnification can be seen in the case of Mercury or DDT. The concentration of Mercury/DDT increases at the successive trophic levels. DDT concentration in zooplankton gets magnified when DDT contaminated water is consumed by the Zooplanktons. In the successive trophic levels like, small fish, big fish, and at top carnivore, the magnification is much higher, which proves the event of Biomagnification.
- A pollutant having properties like long life, mobile, soluble in fat, biologically active will lead to the process of biomagnification.
- Persistent Organic Pollutants (PoPs), dioxins, heavy metals all are agents of biomagnification since they persist in the environment and magnify in the food web.
- In the case of an Oil spill, the oil can get absorbed by the fatty tissues of the fishes and which accumulates there and later when they are consumed by the bigger fishes or successively by humans this will cause Bio-Magnification as the concentration of toxicant gets increased across the entire food chain.