Dioxin — a highly toxic chemical compound — has been found in a soil sample collected near a contaminated site in Kashmere Gardens, the Houston Health Department says.

The sample was taken near the Union Pacific railyard, which is contaminated with creosote — a likely human carcinogen — that resulted in the neighborhood being deemed a cancer cluster in 2019. Union Pacific claims they have been working to investigate and clean up the railyard land for the past 30 years, although critics say the company’s plan isn’t robust. 

As a result, the Houston Health Department recently began testing the area for dioxins in soil near the former railroad creosote treatment facility, according to a press release. The chemical compound was found last month near Liberty Road and Lavender Street, according to a statement from Mayor Sylvester Turner.

“The finding of Dioxin in the Fifth Ward and Kashmere Gardens area is noteworthy and underscores why we are working aggressively to protect families and their children,” Turner said. “We already know that the Texas Department of State Health Services found a higher-than-expected cancer rate of acute lymphoblastic leukemia at nearly five times the expected rate.”

Dioxins are highly toxic chemicals and can cause cancer, reproductive and developmental problems, damage to the immune system, and can interfere with hormones, according to the EPA’s website. Additionally, the compound is extremely persistent and breaks down very slowly over time. 

After initially discovering the compound, the health department began gathering more samples to conduct further tests.

“We’re concerned, and we also need to act rapidly to protect our citizens,” said Loren Hopkins, Houston’s chief environmental science officer.

The city and the Harris County Attorney’s Office announced earlier this month that they plan to sue Union Pacific over its proposed cleanup plan, which critics like Harris County Attorney Christian Menefee say doesn’t do enough to alleviate the issues caused by the contamination. 

“These findings support what residents of Kashmere Gardens have been telling us about their exposure to toxic chemicals. This is inexcusable and shouldn’t happen in the richest country in the world, or anywhere for that matter,” Menefee said in a statement. “We cannot wait to take action to protect the people living in this community.”

Union Pacific did not respond to a request for comment. 

According to the Harris County Attorney’s Office, the notices of intent to sue will be sent within the coming weeks to Union Pacific, the EPA administrator, the U.S. Attorney General’s Office, and the TCEQ.

“The residents of Kashmere Gardens have been through a lot, and they have every right to be informed about the findings. Like anyone else in Houston, they have a right to demand and expect a safe environment, and the City will never stop advocating on their behalf,” Turner said.