It's good that there have been several newspaper articles recently and items on TV like this one, as the public have a right to know the truth.
Someone likened breathing bleed air to smoking. It's bad for you, and some people can smoke their whole lives with no ill effects, while others can get struck down with lung cancer or other nasty diseases after only a relatively small time. It's the same with bleed air - it's just a question of who is susceptible to it, and how much exposure they need for problems to start manifesting themselves.