An air quality alert has been issued for New York City and the surrounding tri-state area due to elevated levels of fine particulate matter (PM 2.5) in the air. The Air Quality Index (AQI) is expected to peak at just over 100, categorizing it as 'Unhealthy for sensitive groups.' These particles, primarily from fossil fuel combustion, are small enough to be inhaled into the lungs, posing health risks to sensitive populations, including children, the elderly, and individuals with respiratory conditions.