Sorry the context of this question doesn’t make sense, can you explain further?
An indicator species is an organism whose presence, absence or abundance reflects a specific environmental condition. Indicator species can signal a change in the biological condition of a particular ecosystem, and thus may be used as a proxy to diagnose the health of an ecosystem.
The answer is most likely than, it is because the poor does not acquire large sum of money where in they could use to ensure safety in terms of their health. Such as having enough money to have regular check ups, vaccines or medicine. They would likely spend the money that they acquire to food and shelter because it is more essential to them. That is why they are prone to have or acquire diseases than the affluent.
