Question

If a water body have high amount of DDT it's 'Biochemical Oxygen Demand' (B.O.D.) will

• A. Decrease
• B. Not affected
• C. Increase
• D. First decrease than increase

Answer 1

Answer: (C)

Increase

Biological Oxygen Demand (BOD) is one of the most common measures of pollutant organic material in water. BOD indicates the amount of putrescible organic matter present in water. Therefore, a low BOD is an indicator of good quality water, while a high BOD indicates polluted water. When BOD levels are high, dissolved oxygen (DO) levels decrease because the oxygen that is available in the water is being consumed by the bacteria. Since less dissolved oxygen is available in the water, fish and other aquatic organisms may not survive.

So, the correct option is 'Increase'.