Or If it is true that all pollutants are harmful identify which of the following is invalid to infer from it ?

The statement 'All pollutants are harmful' is a universal affirmative proposition (All A are B). In formal logic, this implies that pollutants are a subset of harmful things [t5]. It also implies that 'No pollutants are non-harmful' (obversion) and 'Some pollutants are harmful' (subalternation). However, the converse 'All harmful things are pollutants' (If anything is harmful, it is a pollutant) is a logical fallacy. A universal affirmative statement cannot be converted simply; while all pollutants may be harmful, there are many harmful things (such as pathogens or physical trauma) that are not classified as pollutants [c4][c5]. Scientific literature notes that while pollutants cause undesirable changes and health implications [c1][c5], the relationship between exposure and harm can be complex, with some substances only becoming harmful at specific doses [t2]. Therefore, inferring that all harmful things must be pollutants is invalid.

Sources

1. [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 6: Environmental Degradation and Management > Introduction > p. 32
2. [2] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 17: Contemporary Issues > ENVIRONMENTAL POLLUTION > p. 37
3. [3] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 6: Environmental Degradation and Management > Consequences of Air Pollution > p. 39