Thank you for your question!
Certainly, we are related with everything and everything has a purpose. If you get a disease, that is a karmic account which could arise through our previous dealings with Nature, for the body is composed of the same elements as Nature, as you mentioned the “5 elements.”
Rather than being worry about “karmic accounts,” I would suggest to work on the self, to become egoless. Then, our karmic accounts will be settled, because they will no longer affect us. When something does not affect us, the account is over. Also, our activity will be “natural” and flowing with the Drama, rather than what “we think” is right.
We may need to recognize that whatever we do to “others,” we do it to ourselves ultimately.That is why the distinction between “I” and “others” is artificial.