LOS ANGELES (KNX 1070 NEWSRADIO)  -- You might not want to inhale too much after tonight's fireworks shows - even if you don't go to a show yourself. Public health officials are warning people with heart ailments or breathing problems that pyrotechnic displays release lots of toxic substances. They're telling sensitive people to avoid going to fireworks shows, stay upwind, or just plain stay inside.  

Every year, levels of pollutants like carbon soot and highly poisonous barium leap about a hundred-fold on July 4th. They don't return to normal until about noon the next day.