The native Americans made up the largest percentage of California population in 1840.
The symbolic <span>nature of language means that a word represents what it is referring to either by association, resemblance, or convention
Only less 10% of our day to day communication being done through verbal language, while the rest being conducted through non-verbal/symbolic language.
For example, we could communicate that we're currently sad without saying anything simply by crying in front of a person. because The act of crying is associated with the feeling of sadness. </span>
I believe the answer is: No, this does not need to be reported since it is unrelated to participation in the study.
Unless a person is induced with chemical substance, The cause of heart attack is most likely diet and lifestyle that has been building up over time.
Since the research is revolved around attitudes towards hygiene and disease prevention, they would only observe the subject's behaviour, not making them digesting any substance.