In Houston, Texas, residents of two historically African American neighbourhoods with high rates of certain cancers are seeking answers after toxic waste from a nearby railway yard contaminated their environment.

Some suspect the pollution is the cause of a cancer cluster discovered in their area in 2019.

Residents say the area used to be full of life. Now, the streets are lined with vacant houses and most of the community knows someone who has cancer or who has died of the disease.

"Everybody was family and now, everybody is dead that I grew up with," said Andre West, who was raised in the Fifth Ward and Kashmere Gardens, the two east Houston neighbourhoods that were identified as part of a cancer cluster.

The groundwater beneath more than 100 properties is contaminated with creosote, a chemical mixture classified as a probable carcinogen that was used for nearly 75 years at the railway yard. But railway giant Union Pacific, which owns the yard, says the neighbourhoods could not have been exposed to the contaminant, and claims the creosote has nothing to do with the cancers.

In a statement sent to Fault Lines, Union Pacific said: "Union Pacific sympathizes with residents who are dealing with medical issues. Decades of testing show there is no creosote pathway to reach property owners, and recent health studies lack scientific testing needed to make any firm conclusions about the cause of their medical conditions.

"The Texas Commission on Environmental Quality has monitored, directed and approved all of our work at the site for nearly 30 years. We will continue working with the agency and informing property owners in the groundwater zone of any new developments, as we have done since the early 1990s."

The Texas public health agency has not yet decided if it will investigate what could be causing the illnesses - a process that advocates say often leaves communities without answers.

"There’s no clear way to distinguish what’s causing it without investing a great deal of money, and government’s not doing that," Stephen Lester of the Center for Health, Environment & Justice told Fault Lines.

How do communities living alongside polluting industries and toxic waste look for answers and accountability when they get sick? Fault Lines investigates the cancer cluster in east Houston and follows a community’s search for justice.

Source: Al Jazeera