Since last year, Reuters has obtained neighborhood-level blood lead testing results for 34 states and the District of Columbia. This data allows the public its first hyper-local look at communities where children tested positive for lead exposure in recent years.

The newly identified communities with high rates of elevated childhood lead levels include a historic district in Savannah, Georgia, areas in Rutland, Vermont, near the popular skiing mountain Killington, and a largely Hasidic Jewish area in Brooklyn.

The areas where the most children tested high are in Brooklyn, including neighborhoods with historic brownstones and surging real estate values, where construction and renovation can unleash the toxin. The worst spot – with recent rates nearly triple Flint’s – was in a Hasidic Jewish area with the city’s highest concentration of small children.

The updated map includes other minor changes. Recently, the CDC provided testing results to correct data it previously released to Reuters for Pennsylvania, Ohio, New Jersey, Virginia and Louisiana. Responding to earlier records requests, the CDC mistakenly released test results for all children under 16, though the news agency requested testing results for children under six – the age group most likely to be affected by lead exposure.

While the number of children with high lead levels has plummeted across the U.S. since leadpaint and gasoline were phased out in the 1970s and 1980s, many communities remain exposed to the toxic heavy metal, the data show.

In all, Reuters has identified 3,810 neighborhood areas with recently recorded childhood leadpoisoning rates at least double those found across Flint, Michigan, during the peak of that city’s water contamination crisis in 2014 and 2015. Some 1,300 of these hotspots had a rate of elevated blood tests at least four times higher than Flint’s.

Reuters defined an elevated result as any test higher than the Centers for Disease Control and Prevention’s current reference number of 5 micrograms per deciliter, the level at which the agency recommends a public health intervention.

Williamsburg woes

Decades ago, Williamsburg, Brooklyn, was a low-rent and largely industrial area. Today, its spacious lofts and privileged perch across from downtown Manhattan attract the well-heeled.

Working-class residents remain, too, including thousands of Hasidic Jews from the Satmar sect, who have settled in the neighborhood’s southern zone since World War II. With their distinctive dress and traditions, the Hasidim’s orthodox lifestyle strikes a contrast to the hipster glitz encroaching nearby.

Hasidic Williamsburg suffers alarming rates of childhood lead poisoning, ranking as the riskiest spot Reuters found citywide.

Across three southern Williamsburg census tracts, as many as 2,400 children tested at or above the CDC’s current elevated lead threshold between 2005 and 2015. In one, 21 percent of children tested during this period had high lead levels. Rates in the most recent years were lower, but still above Flint’s.

On Lee Avenue, boys wearing black hats and coats stream out of yeshivas, while women shop in kosher markets and kibitz in Yiddish in front of old brownstones, many built around 1900.

“When I saw the numbers I freaked out,” said Rabbi David Niederman, head of the United Jewish Organizations of Williamsburg. “The concentration of old housing and the number of children in them are big factors.”

In Hasidic Williamsburg, around 25 percent of the population is age five or younger, compared to about 6 percent citywide.

In recent years, city health workers homed in on the poisoning cluster. UJO and other groups helped health officials conduct outreach, distributing lead awareness pamphlets in Yiddish, urging clinics to boost screening, and holding meetings for residents and landlords.

As recently as 2015, one area tract had a rate of 13 percent, the highest in the city. It’s too early to tell whether rates have since dropped.