The 'Red Data Book' is related to

The 'Red Data Book' (also called the Red List) is an international catalogue maintained by the IUCN (International Union for Conservation of Nature) that documents the conservation status of plant and animal species, classifying each one by how close it is to extinction — critically endangered, endangered, or vulnerable.

Because the Red Data Book's entire purpose is to record species at risk, its subject matter is animals nearing extinction — that is exactly what it is 'related to'.

• River pollution is tracked through water-quality monitoring by bodies such as the CPCB and State Pollution Control Boards, not through a species-status register.

• A falling groundwater table is assessed through hydrological and groundwater-board surveys, an entirely separate concern from species conservation.

• Air pollution is measured via air-quality indices and emission data, again unrelated to a species-conservation catalogue.

So the Red Data Book is related to species — specifically, animals (and plants) near extinction.