What does hazardous air quality mean? How Canada wildfire smoke is impacting DE, PA, NJ

If you've been outside this week, then you've noticed the hazy and smoky atmosphere surrounding the area.

All along the East Coast, residents have been dealing with the smoke from the Canada wildfires that have severally reduced air quality throughout the region.

Agencies from multiple states have issued alerts because the air quality is unhealthy, impacting older adults, children and those with conditions such as asthma and heart and lung disease. In some areas, air quality is so poor that it's hazardous to everyone.

These states include:

Weather forecast: How long is the wildfire smoke going to last? See forecast for Delaware, New Jersey & PA

Where is the smoke coming from?: Blame Wednesday's poor air quality on Canadian wildfires

Delaware

The First State's Department of Environmental Protection issued a Code Red Air Quality Action Day for Thursday with the anticipation of Code Orange for Friday.

New Jersey

The state Department of Environmental Protection declared an Air Quality Action Day for Thursday before upgrading to the "Unhealthy category" statewide through Friday night.

Pennsylvania

The state Department of Environmental Protection issued a Code Red Air Quality Action Day across Pennsylvania for Thursday. Smoke from Canadian wildfires is contributing to high levels of fine particulate matter in the air, the department said.

Here's a look at what it all means:

What are air quality alerts?

Air quality alerts are indicators the air is unsafe to breathe for certain people. Alerts are triggered by a number of factors, including the detection of fine-particle pollution — known as “PM 2.5” — which can irritate the lungs.

Pollution is detected by a system of monitors on the ground “constantly taking measurements of the amount of chemicals and particles in the air,” said Susan Anenberg, professor and department chair of environmental and occupational health at George Washington University.

What does hazardous air quality mean?

Here is how to read the categories for the AQI index:

• Good: 0 to 50. Air quality is satisfactory and pollutants pose no risk

• Moderate: 51 to 100. Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.

• Unhealthy for Sensitive Groups: 101 to 150  Members of sensitive groups may experience health effects. The general public is less likely to be affected.

• Unhealthy: 151 to 200. Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.

• Very Unhealthy: 201 to 300. Health alert: The risk of health effects is increased for everyone.

• Hazardous: 301 and higher. Health warning of emergency conditions; everyone is more likely to be affected.

How does the atmosphere affect wildfire smoke?

Atmospheric dynamics can carry wildfire smoke through the air and allow it to travel long distances, said Anenberg, who also directs the GW Climate and Health Institute.

“It’s strange to think about how a wildfire event that’s several hundred miles away can affect the air quality here (but) it’s not a unique phenomenon,” she said.

Due to an area of low pressure hovering offshore and an area of high pressure over Canada, a northerly flow of air was funneling the smoke south into the U.S. from Canada, AccuWeather said.

When will air quality get better?: Smoke from Canadian wildfire to linger in Delaware, PA & NJ

Canadian wildfire smoke map: See where the haze is headed in Delaware, New Jersey and PA

How does air pollution affect human health? Who is at risk?

Fine-particle pollution can affect every organ of the body, Anenberg said.

Studies show particle pollution has been linked to various health problems, according to the EPA, including:

• Premature death in people with heart or lung disease

• Nonfatal heart attacks

• Irregular heartbeat

• Aggravated asthma

• Decreased lung function

• Increased respiratory symptoms, such as coughing or difficulty breathing

Is it safe to be outside?

Experts are urging residents that they should try limiting their outdoor exposure. The U.S. Environmental Protection Agency on Wednesday provided these tips:

• If it looks or smells smoky outside, take it easier to reduce how much smoke you inhale.

• Choose a mask that will help protect you from smoke.

• Limit time spent outdoors by performing only essential activities and take frequent breaks indoors.

• Reschedule outdoor work tasks.

Will wearing a mask help?

Yes, it will. The better the mask, the more it will help, and just like during the pandemic, make sure it's covering your nose and mouth. A mask will make it more bearable, but you still don't want to be outside long in these conditions.

N95 respirator masks provide the best protection from wildfire smoke, according to the EPA. Cloth masks will not protect you from wildfire smoke.

Should I keep my pets indoors?

Pets have lungs and hearts, too. Do your best to limit your pet's time outside. Your dog might not like it but cut the walk short.

Contributing: Elizabeth Weise and Doyle Rice, USA TODAY; Associated Press.

This article originally appeared on Delaware News Journal: What does hazardous air quality mean? Impact on Canada wildfire smoke