Childrens’ blood lead levels in Flint, Mich., have dropped to their lowest all-time levels, according to a new study by the Journal of Pediatrics. The data, researchers say, could be an indicator that attempts to combat the city’s four-year-old water crisis may be making an impact.

The Detroit Free Press reports that the research, indicated by 15,817 blood samples from children 5 years old and younger, was taken throughout the year from January 1, 2016 to December 21, 2016. The percentage of children with blood levels over 5 micrograms per deciliter — the amount that the CDC claims is cause for intervention — dropped from 11.8% to 3.2%. Additionally, the average amount of lead in their blood samples also dropped from 2.33 micrograms per deciliter in 2006 to 1.15 in 2016.

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Long awaited improvement

In the study, which spans 11 years, the changes that were made following the 2014 discovery has proven to change the tides of the city for the better and proves to have made a huge impact on the health of the city. Not only is it the best report since the levels switched, but since the beginning of the study.

Dr. Hernan Gomez, the lead author of the study and a medical toxicologist and pediatrician at Michigan Medicine, believes that the changes are the results of efforts to turn the crisis around. “That is a direct result of lead abatement efforts and citizens following warnings to use filters, bottled water and have their water tested and the like,” he said.

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The study claims that changes in water filters, pipe replacements and water supply sources in the industrial city about an hour north of Detroit are among the reasons for the research results. But the city is far from rejoicing. Residents are still being instructed to stick to bottled water over the city’s supply until at least 2020, when all of the lead pipes are reportedly scheduled to be replaced.

In the meantime, as the city waits for it water infrastructure to be restored, a Lifetime movie on the topic is set to debut in October. Meanwhile countless donations from celebrities ranging from Dave Chappelle to Bruno Mars, have come in. Also, federal indictments for the mishandling and mistreatment of Flint residents have moved forward.