If you put batteries in a bath tub and sit in the bath what would happen

With normal AA/AAA/9 volt batteries, you most likely won't get shocked. There might be some bubbles coming out from the battery though, and that is because the electricity breaks down the water into hydrogen and oxygen (called electrolysis).

"air pollution" is the correct answer i believe

Some of their responsibilities are to evaluate safety, efficiency, and effectiveness of the biomedical equipment. train people on how to properly operate biomedical equipment. lastly is to research the engineering aspects of the biological systems of humans and animals.