The air quality index (AQI) in Larchmont was at a record highs, measuring 325 at 11:00 pm Wednesday according to airnow.gov.

The Environmental Protection Agency and partners, such as the New York State Department of Environmental Conservation, maintain this website where you can find air quality information for your specific location.

This level of pollution is considered unhealthy for everyone–and it is expected to stay high until late Thursday or Friday. The higher in AQI number, the greater the health risks.

The main unhealthy pollutant from wildfire smoke is called PM2.5, which is “particulate matter” less than 2.5 microns in size– that’s very tiny. (For comparison, a human hair is about 70 microns and a human red blood cell is about 5 microns across.)

Another unhealthy pollutant for sensitive or at risk people is PM10, which is particulate matter less than 10 microns. People who may be especially sensitive to PM10 include the very young, and those with preexisting respiratory problems, such as asthma or heart disease.

An N95 or KN95 face mask can protect you from the particulate matter from wildfire smoke, but you should only use this type of mask a few times and then toss it because  the mask becomes less effective after a few uses. If conditions are very hazardous, experts advise to only use it once.

A toll-free air quality hotline has been established so New York residents can stay informed on the air quality situation. The toll free number is 1-800-535-1345.

You can also track pollution levels for your zip code at The Weather Channel here.