UCLA has issued an apology and an updated report on secondhand smoke after a methodology error skewed researchers' findings.
The original report, issued last month by the UCLA Center for Health Policy Research, reported 2.5 million California children under the age of 12 were either exposed or at risk of exposure to secondhand smoke.
On Wednesday, researchers updated the findings, revising the total number to 966,000.
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"The errors were related to pooling three cycles of CHIS data. The center regrets the error," according to UCLA.
Other changes include the total number of children who live in homes where smoking takes place indoors. The original report estimated that group at 561,000. The new estimate is 224,000.
The number of kids who have at least one family member that smokes outside dropped from 1.9 million to 742,000.
The center is standing by the report's percentages, interpretation and findings.
Such an error is rare, said Gwen Driscoll, the center's director of communications.