SOUTH LAKE TAHOE, Calif. — The air quality around the Lake Tahoe Basin made history this week, with at least three towns, including South Lake Tahoe, Incline Village and Kings Beach, recording the worst air quality in the United States.

South Lake Tahoe’s air quality was reported as unhealthy by IQ Air, with an AQI 193 rating at times on Tuesday. Incline Village was reported to be at 330, which is considered to be hazardous, but the smoke continues to fluctuate all around the lake. It’s mainly been hazardous since Friday afternoon after a brief break.

An official from the National Weather Service in Reno said that with an increase in southwest winds in the afternoon, the smoke from the Caldor Fire is being thrust directly towards Tahoe and the surrounding communities, including Truckee, Carson City and Reno. These winds are expected to continue into Thursday, with an end to this smoke unclear to officials.

The El Dorado County Air Quality Management team said that a healthy air index is considered to be any number under 100. Between 100 and 150, people who are sensitive might begin to feel the effects of the unhealthy air levels, and above 150, it is considered unhealthy for everyone.

The Washoe County Health Department issued an Stage Three Emergency Episode, notifying the public that the air is unhealthy outside, after the AQI reached a record number of 291 on Monday for over 24 hours.

“You want to stay indoors as much as possible,” said senior air quality specialist for Washoe County Craig Petersen. “Really restrict any outdoor activity that you must do.”

One concern that rises from the amount of smoke outside is the amount of PM 2.5, or particulate matter, residents and animals in the area are inhaling. PM is a mixture of solid particles and liquid droplets in the air, which are small enough to not only be inhaled into our respiratory system, but can eventually cause more serious health issues if inhaled long term.

“PM 2.5 is a very, very small particle,” said Petersen. “So being that it’s so small, this size particle beats our body’s natural defenses. So you’re able to breathe this stuff deep into your lungs, and it can actually get passed … from your respiratory system and to your bloodstream. So if you have long term exposure to this kind of particulate pollution, it can also have cardiovascular effects such as heart disease.”

Short term effects of PM 2.5 inhalation include shortness of breath, a burning throat, and potentially burning eyes.

Petersen said that animals are also most likely feeling similar health effects to residents in town, so it’s important to keep pets inside as well.

While the situation is unfortunate, Peterson suggested many ways to combat the smoke for now until conditions improve. He said the first solution is making sure to change the filters on any at-home air conditioner units.

“If you can spend the extra money, put in a better filter and then run the air conditioner as much as possible,” said Petersen. “That’ll keep your home clear from the smoke.”

He also recommends that if you cannot afford an air conditioner or air purifier, the best solution is to make sure all windows and doors are completely shut and sealed. N-95 masks are the only masks that will effectively keep the PM 2.5 particles out of your respiratory system, but if they are not sealed on your face properly, they also will prove to be ineffective.

As a result of the deteriorating air quality, Washoe County School District canceled classes for an estimated 67,000 students, including those at Incline high and elementary schools. The district was able to install commercial grade HVAC systems to aid in ventilation in classrooms and halls, but still announced they would cancel classes for the day due to concerns of smoke outside and COVID inside.

The Lake Tahoe School leader Robert Graves notified parents in an email sent on Tuesday they have ordered AQI sensors that will be placed indoors throughout the main building and in the APAC. The school is also excited to begin the process of installing HEPA filters to their air filtration system. The filters are expected to arrive this week.

In South Tahoe, Douglas County School District is prepared to use their air conditioning units to keep good airflow in their buildings, and plan on keeping their students indoors to avoid smoke inhalation. They will keep track of the air quality using the Purple Air website, and schools will be closed if the reading is higher than 300 PM 2.5.

South Lake Tahoe Unified School District has begun to develop a plan for the year based on emergency weather conditions, and if outside air quality is between 150 and 300 PM 2.5, then all staff and students will be required to stay indoors.

Additionally, many outdoor events that were planned for the weekend have been postponed or canceled due to the smoke.

Nevada State Parks closed on Monday, Aug 23 due to the hazardous air quality, and are expected to reopen this Friday, Aug 27, depending on conditions. Parks include Sand Harbor, Spooner Lake, Spooner Backcountry, including Marlette/Hobart, Backcountry, Cave Rock, and Van Sickle.

Tahoe Brewfest was also rescheduled to Sept. 25 due to the unhealthy air quality. If ticket holders are unable to attend the newest date, they will be able to get a refund up until the day of the event.

Similarly, Harvey’s announced they would be postponing Eric Church with Paul Cauthen at the Harveys Outdoor Arena for this weekend. The concert will now be held Aug. 27-28 of next year, and ticket holders will still be able to attend.