A judge in the US state of Texas has upheld a $3 million jury verdict by ruling in favor of a family who claimed that oil and gas drilling near their land made them sick. The landmark case is being hailed as a victory by anti-fracking activists.

The Texas ruling is the latest step in a three-year case that began when Bob and Lisa Parr filed suit against a handful of oil companies claiming that fumes from drilling around their 40-acre (16-hectare) ranch exposed them and their livestock to hazardous gases and industrial chemicals.

Some of the initial claims related to hydraulic fracturing, or fracking, operations were settled out of court or dismissed, but the complaint against Aruba Petroleum was sent to a jury trial in Dallas County Court, becoming one of first to reach this stage of litigation.

In April, the jury awarded the Parrs $275,000 for the drop in their property value, $2.4 million for past physical suffering and mental anguish and $250,000 for future harm.

A move by Aruba to overrule the judgment was denied, but the oil company, focused on the Barnett shale formation in Texas, will request a new trial and if that fails will appeal the ruling, its lawyer said.

The Parr family was featured in the anti-fracking documentary Gasland Part II by filmmaker Josh Fox. Its claims were not about fracking per se but instead about air emissions on the surface from diesel-powered trucks and gas wells.