Question

Paddy fields require a large amount of water. The pesticides and chemical fertilizers used are washed down into the soil or waterbodies. How do these chemicals reach our bodies? What is this phenomenon known as?

Hint:

Toxins increase along food chain = Biomagnification.

Answer 1

How Do These Chemicals Reach Our Bodies?

Pesticides and chemical fertilizers used in paddy fields are often washed away by rainwater into nearby rivers, lakes, and groundwater. These chemicals enter the ecosystem and follow a specific pathway before reaching humans. The process occurs as follows: – The chemicals mix with water and soil.
– Small aquatic plants and organisms absorb these chemicals.
– Small animals or fish feed on these plants.
– Bigger fish eat smaller fish.
– Humans consume contaminated water, fish, vegetables, or crops. As the chemicals move from one trophic level to the next, their concentration increases at each stage of the food chain.

Name of the Phenomenon:
\[ \boxed{\text{Biomagnification (Biological Magnification)}} \]

Explanation of Biomagnification:
Biomagnification is the process by which the concentration of harmful chemicals increases progressively at higher levels of the food chain. Since many pesticides are non-biodegradable, they accumulate in the tissues of organisms. When predators eat many contaminated organisms, the concentration of these chemicals becomes very high in their bodies. Humans, being at the top of many food chains, accumulate the highest concentration.

Conclusion:
The pesticides used in paddy fields enter water and soil, move through the food chain, and finally reach humans. This increasing concentration of harmful chemicals at higher trophic levels is known as biomagnification.