The state urged residents of the Baltimore region to take precautions today because air quality is expected to approach unhealthful levels.
The air quality yesterday was moderate, with an index reading at 4 p.m. of 71 for ground-level ozone. The air is declared "Code Orange," or approaching unhealthful levels, when the ozone readings are 89-99. It is "Code Red," or harmful, when the index reaches 100 or above.
This summer, the index has registered over 100 on July 8, July 6 and June 22, according to the Maryland Department of the Environment.