"Danger In Air Near Metal Recyclers"
"The calls to the city of Houston's 311 help line came in the early morning and the middle of the night - complaints of red smoke, yellow smoke, explosions, fire, a child having trouble breathing."
"Reports like these - 189 of them over the last five years - led Houston air authorities to discover a previously unrecognized and dangerous source of air pollution: metal recyclers and car crushers, according to interviews and documents obtained by the Houston Chronicle.
The smoke comes from cutting metal with torches and from fire when vehicle gas tanks aren't drained properly. Explosions can occur when propane tanks are fed into the maw of the crushers."Source: Houston Chronicle, 12/31/2012