How dangerous was Ohio chemical train derailment?

Headaches and lingering chemical smells from a fiery train derailment in East Palestine, Ohio, have left residents worried about their air and water. A chemical-spill expert explains that the actions currently being taken in Ohio are very similar to what's happening at hazardous-waste contamination sites around the country. Comments from Andrew Whelton, professor of civil, environmental and ecological engineering, Purdue University.