HOUSTON (CBSDFW.COM/AP) — Texas health officials have identified a cancer cluster in a north Houston neighborhood polluted by the wood preservative creosote from a nearby railroad operation.

The Department of State Health Services said it didn’t try to determine what caused the lung and bronchus, esophagus and larynx cancers in the Fifth Ward and Kashmere Gardens. But residents believe it proves their long-held suspicions about pollution from the Union Pacific site.

The Texas Commission on Environmental Quality requested the assessment because of residents’ health concerns. Union Pacific tells the Houston Chronicle that it is reviewing the study.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)