PM2.5 — is expected to push the Air Quality Index over 100, reaching levels unhealthy for sensitive groups, including children, older adults, and people with heart or lung conditions.

Hazy skies descend over the New York City area again on Tuesday, re-upping some air quality alerts related to Canadian wildfire smoke. As of 10 a.m., the air quality index was 121, which is considered unhealthy for sensitive groups.

Breathing in polluted air for extended periods of time can pose a serious health risk for people, especially for vulnerable populations.