Lead poisoning is a serious health issue for many young children and their families. Lead has been shown to be particularly harmful to children between the ages of nine months and six years. The only way to know for sure if a child has been poisoned is to get the child tested for lead.
https://www.phila.gov/2018-11-16-landlords-and-tenants-preventing-childhood-lead-poisoning/
The Collected Works of Jim Garrow 