Find some sentences with the past participle.

So many thousands of terrified people died. He found that it came from the river polluted by the dirty water from London. But he became inspired when he thought about helping ordinary people exposed to cholera. From the stomach the disease quickly attacked the body and soon the affected person died. He became interested in two theories. Neither its cause nor its cure was understood. The water companies were instructed not to expose people to polluted water any more.