*Asthmatic's concern, 10 letters
Pollution rating, 10 letters
0-to-500 scale that goes from least to most hazardous, 15 letters
It corresponds to a six-color scale ranging from green to maroon, 15 letters
Pollution measurement, 15 letters
Speak with one's hands?, 8 letters
Gesturer's emphasis, 9 letters
Sign of sarcasm?, 9 letters
Two-handed gesture used for ironic effect, 9 letters