When does lead becomes dangerous to humans?

Answer 1

Lead becomes legally hazardous to humans when the lead level is above 1000pm.

Answer 2

Lead is particularly dangerous as it is a cumulative poison; it doesn't get removed from the body. So even small quantities over a long period of time will accumulate in the body.

Answer 3

If enough lead enteres your blood stream or anywhere in your body, you can get lead poisoning. And yes, lead poisoning can kill you if there is enough inside you.