Environmental health: practice question

A PSM question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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PSM · Environmental health

Sample item

Which water-quality measure indicates recent faecal contamination?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Escherichia coli count

E. coli is used as an indicator of recent faecal contamination because it is abundant in human and animal faeces and should be absent from safe drinking water.

Option by option

  • A. Chloride concentration only

    Chloride alone does not indicate pathogens.

  • B. Temperature alone

    Temperature alone does not establish contamination.

  • C. Escherichia coli count (correct)

    Correct: E. coli signals faecal contamination risk.

  • D. Water colour alone

    Colour can change for many non-faecal reasons.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More PSM questions

Questions about this PSM question

What is the answer to this PSM question?

The best answer is C, Escherichia coli count. E.

Why is "Chloride concentration only" not the answer?

Chloride alone does not indicate pathogens.

Why is "Temperature alone" not the answer?

Temperature alone does not establish contamination.

Why is "Water colour alone" not the answer?

Colour can change for many non-faecal reasons.

What concept does this question test?

It tests Environmental health in PSM. coli is used as an indicator of recent faecal contamination because it is abundant in human and animal faeces and should be absent from safe drinking water.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Environmental health?

Practise biostatistics with small calculations until sensitivity, predictive values and risk measures are automatic. Then use the flashcards and the other PSM questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.