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.
One such argument would be that <span>Investments by the upper class create lower-class jobs.
Although wealth gap is indeed a serious problem and needs to be dealt with, there are certain counter arguments which prove the opposite. This is one of them, given that upper classes invest a lot of money in the country so lower classes can work as well.
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The answer is the location of the capital!
they made a deal to put the new national capital in the south
