For Gaby Mendez Ulloa, an upcoming action by the Environmental Protection Agency, or EPA, isn't just some obscure government rulemaking. It's a life-or-death issue.
Over the past few years, the EPA has been working on new standards for nitrogen oxide, or NOx, emissions from heavy-duty trucks — a key ingredient of the brownish haze that blankets the valley east of Los Angeles where Mendez Ulloa lives. Experts expect the proposed rule, currently under interagency review, to be released any day now.
