Atlantic:
“None of the samples Walters sent were safe to drink. Some had lead content of 200 parts per billion. Over 30 samples, the average lead content was 2,000 parts per billion, which meant that no matter how long Walters let her taps run, it still would have been toxic. This could easily have been causing the health problems that Walters and her children were experiencing.
“Lead is the best known neurotoxin, it adversely impacts every system in the human body,” Edwards told me. “Certainly it could have caused children’s lead poisoning.”
The city says it does not know why so much lead was found in Walters’ pipes, but Edwards has a theory: Many cities have lead pipes, and when water sits in those pipes, the lead can leech into the water. So cities usually add corrosion-control chemicals, such as phosphates, to keep the lead out of the water. But because Flint didn’t take such precautions when they began pumping their own water, “the public health protection was gone,” Edwards says.”
See the other 'lead' tagged articles on this site. The best crime prevention may be lead reduction programs. A causal link not understood by many city government officials.
Also this is article on Chicago water pipes and lead pollution. Some of the violence in Chicago is likely attributed to lead pollution.
