Question

Consider the following regarding qualitative and quantitative pollutants:

1. Qualitative pollutants include substances introduced exclusively by humans.

2. Quantitative pollutants are harmful only when their concentration increases.

3. Mercury is a qualitative pollutant.

• A. 1 and 2 only
• B. 2 and 3 only
• C. 1 and 3 only
• D. All of the above

Answer 1

Answer:

A. 1 and 2 only

• Correct Answer: Option C) 1 and 3 only

• Environmental pollutants can be classified as qualitative or quantitative based on their nature and impact:

• Qualitative pollutants are substances that are not naturally present in the environment and are exclusively introduced by human activities. These are synthetic compounds that do not exist naturally and are completely foreign to the ecosystem. Examples include DDT, plastics, and many synthetic chemicals. Statement 1 is correct.

• Quantitative pollutants are substances that naturally exist in the environment but become harmful when their concentration increases beyond natural levels. These substances are not inherently harmful at normal concentrations. However, statement 2 is incorrect because it suggests quantitative pollutants are harmful "only" when their concentration increases, which is an oversimplification. Even at low concentrations, some quantitative pollutants can be harmful depending on the specific ecosystem or organism.

• Mercury is indeed a qualitative pollutant because although mercury occurs naturally in trace amounts, the forms of mercury that cause pollution (particularly methylmercury) are often created through human activities like coal burning, mining, and industrial processes. These transformed mercury compounds are not the same as those occurring naturally. Statement 3 is correct.