Heat, still air cause spike in smog Houston Chronicle Copyright 2012 Houston Chronicle. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Published 08:24 p.m., Wednesday, June 27, 2012 The burst of heat and stagnant air, two of the key ingredients needed for harmful amounts of smog to form, pushed ozone levels to 136 parts per billion Tuesday - the highest mark in the eight-county region since August 2003. David Brymer, the TCEQ's air quality chief, said a high-pressure system and long hours of sunlight created the ideal conditions for ozone. Tuesday's smog mark, in particular, "proves that while we have made progress, we are a long way away from achieving healthy air for Houston," said Matthew Tejada, executive director of Air Alliance Houston, an environmental group. Pulmonologist Richard Castriotta said UTHealth hospitals and clinics have seen an increase in patients with allergic rhinitis, asthma and other underlying lung conditions.