Safe water criteria include – a) Free from pathogensb) Free from harmful chemicalsc) Free from chlorined) Free from colour and odoure) Usable for agricultural purposes
**Core Concept**
The concept of safe water criteria is crucial in public health, as it determines the suitability of water for human consumption. It involves evaluating water quality based on the absence of pathogens, harmful chemicals, and other contaminants that can cause harm to human health.
**Why the Correct Answer is Right**
Safe water criteria are established to ensure that water is free from pathogens such as bacteria, viruses, and protozoa that can cause waterborne diseases. Water should also be free from harmful chemicals like heavy metals, pesticides, and industrial pollutants. Additionally, water should not contain excessive amounts of chlorine, which can be harmful in large quantities. The absence of colour and odour is also an essential criterion, as it indicates the presence of organic or inorganic contaminants. Usable for agricultural purposes is not a relevant criterion for safe drinking water.
**Why Each Wrong Option is Incorrect**
**Option B:** Free from harmful chemicals is a correct criterion, but it is not the only correct option, making it incomplete.
**Option C:** Free from chlorine is incorrect because small amounts of chlorine are added to water as a disinfectant to kill pathogens.
**Option D:** Free from colour and odour is correct, but it is a subset of the broader criterion of being free from contaminants.
**Clinical Pearl / High-Yield Fact**
Safe water criteria are essential in preventing waterborne diseases, which are responsible for a significant burden of morbidity and mortality worldwide.
**Correct Answer: B. Free from harmful chemicals**