"AUSTIN — In 2007, Texas regulators quietly relaxed the state’s long-term air pollution guideline for benzene, one of the world’s most toxic and thoroughly studied chemicals. The number they came up with, still in effect, was 40 percent weaker, or less health-protective, than the old one."

"During their careers as oil and gas inspectors for the Texas Railroad Commission, Fred Wright and Morris Kocurek earned merit raises, promotions and praise from their supervisors. ... But they may have done their jobs too well for the industry’s taste—and for their own agency’s."

"The Aleppo pine tree in Randy Smith’s north-side backyard was 82 feet tall and maybe 60 years old. One of many such trees in his neighborhood, its canopy spread across the yard and offered shade and sanctuary."

"The Environmental Protection Agency on Monday rejected parts of a key Texas clean-air plan, setting up a conflict with deep implications both for the state’s electricity mix and air quality across much of the country."

"DuPont Co. ’s chemical plant in La Porte, Texas, for many years has gained a strong reputation among industrial-safety experts for migrating to safer chemicals. ... So when a gas leak at the plant earlier this month caused four employees—two of them brothers—to be fatally overcome by an industrial chemical called methyl mercaptan, some in the chemical safety world were taken aback."

"Bradford Gilde, a Houston lawyer, stumbled across some unexpected evidence as he was preparing to sue Aruba Petroleum on behalf of a North Texas couple who believed fumes from the company’s natural gas wells were making them sick."

"As eastside families mourn the deaths of four workers at DuPont's La Porte chemical plant in a toxic gas release early Saturday morning, federal investigators are gathering to begin probing for answers."

"A week after a historic vote to ban hydraulic fracturing (or fracking — the controversial drilling method that forces oil and gas from shale formations with pressurized water, sand and a host of chemicals), Denton, Texas, has been told the state will continue to issue drilling permits within the city limits."

"A day after voters decided to make Denton the first city in Texas to ban hydraulic fracturing, the reaction by the energy industry and government was swift."