J. David Goodman, Al Baker and James Glanz:

Mikaila Bonaparte has spent her entire life under the roof of the New York City Housing Authority, the oldest and largest public housing system in the country, where as a toddler she nibbled on paint chips that flaked to the floor. In the summer of 2016, when she was not quite 3 years old, a test by her doctor showed she had lead in her blood at levels rarely seen in modern New York. A retest two days later revealed an even higher level, one