What are 4 Bias questions that determine whether the information about dihydrogen monoxide is biased?

An important study at a major university has determined that a chemical found in the typical american diet is extremely dangerous. Dihydrogen monoxide, which is added to many processed foods, has been linked to a number of deaths among people, especially swimmers. Although it is normally a liquid, in its gaseous state it can cause servere burns. Dihydrogen monoxide can even corrode metal. Many drivers involved in automobile accidents had drunk dihydrogen monoxide shortly before driving. why is this substance added to our food?

What are 4 Bias questions that determine whether the information about dihydrogen monoxide is biased?