Question

Which of the following causes biomagnification?
(a) Sulphur dioxide
(b) Mercury
(c) DDT
(d) Both (b) and (c)

Answer 1

Hint: It is defined as the rise or increase in the contaminated substances caused by the intoxicating environment like heavy metals. These toxins get accumulated in the higher organisms.

Complete answer:
The contaminants might be heavy metals such as mercury, arsenic, and pesticides such as polychlorinated biphenyls and DDT. Biomagnification or biological magnification is the process of accumulation of certain chemicals in living organisms to a concentration higher than that occurring in the inorganic, non-living environment. They cause biomagnification in nature.
The major causes of biomagnification are:
- The agricultural pesticides, insecticides, fertilizers, and fungicides are very toxic and are released into the soil, rivers, lakes, and seas. These cause health issues in aquatic organisms and humans.
- Manures and biosolids are processed industrially and contain contaminants like pharmaceuticals and personal care products. These substances have an adverse impact on the health of humans, animals, and wildlife.
- The industries and factories release toxic substances that are released into the soil, lakes, oceans, and rivers. The gaseous emissions pollute the environment which enters into the food chain leading to biomagnification.
- Mining works are proceeding in the deep sea to extract metal like zinc, aluminum, cobalt, silver, and gold. The mining process generates a large amount of selenium and sulfide, which deposits in water and destroys the oceans and coastal regions.
So, the correct answer is ‘both (b) and (c)’.

Note: Higher the trophic level of an organism in the food chain greater will be the magnification of toxic chemicals. Biomagnification makes humans more prone to cancer, kidney problems, liver failure, birth defects, respiratory disorders, and heart diseases.