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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 more commonly found in factory or construction workers and, in some cases, enough to cause irreversible brain damage.

Within two weeks, a city health inspector visited the two Brooklyn public housing apartments where Mikaila spent her time — her mother’s in the Tompkins Houses; her grandmother’s in the Gowanus Houses — to look for the source of the lead exposure, records show. The inspector, wielding a hand-held device that can detect lead through multiple layers of paint, found the dangerous heavy metal in both homes. The Health Department ordered the Housing Authority to fix the problems.

The discovery spurred the Housing Authority to action: It challenged the results.

Rather than remove or cover the lead, the Housing Authority dispatched its own inspector who used a different test, documents show. The agency insisted that however Mikaila was poisoned, there was no lead in her apartments.