Air quality in Washington, D.C.

Air quality index (AQI) and PM2.5 air pollution in Washington, D.C.

Last update at (local time)


Real-time Washington, D.C.
Most polluted city ranking

#cityUS AQI
1 Washington


2 Chevy Chase


(local time)


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Real-time Washington, D.C.
Cleanest city ranking

#cityUS AQI
1 Chevy Chase


2 Washington


(local time)

Unhealthy for sensitive groups
Very unhealthy
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How to best protect from air pollution?

Reduce your air pollution exposure in Washington, D.C.


Is there air pollution in Washington DC?

Washington, D.C., formally the District of Columbia and also known as D.C. or just Washington, is the capital city of the United States of America. It is situated on the banks of the Potomac River. It shares borders with Maryland and Virginia.

The estimated population of 705,749 as of July 2019, makes it the 20th most populous city in the US. The population for the whole metropolitan area was 6.3 million people.

In 2016 it was the most visited city in the entire USA with approximately 20 million visitors.

Does the air quality in Washington DC vary throughout the year?

Washington DC’s highest monthly PM2.5 levels are largely attributable to wood-burning stoves which make up 63 per cent of winter particulates. Washington’s highest daily PM2.5 levels on the other hand are due to seasonal wildfires.

One of the many shocking consequences of the increasing wildfires is far-spreading and long-lasting smoke pollution. Warnings of “hazardous” or “very unhealthy” air quality were in place from California to Washington State, with the air quality in many parts of Oregon ranking among the worst in the world. While the wildfires themselves have been concentrated on the West Coast, the resultant smoke has made its way to the East Coast and even as far as Europe.

Last year, “very unhealthy” air quality ratings lasted for an average of 4.1 days, which is double the average over the previous decade, with more counties experiencing 8+ days of “very unhealthy” air quality.

Wildfire smoke varies depending on its content. Urban fires are often contaminated with plastic waste and other flammable waste products, whereas rural wildfires are more organic and consist mainly of natural flammable substances such as wood, leaves dried grass etc.

How does Washington DC rank in the air pollution stakes?

It would appear to be more difficult to breathe easily in the D.C. metro region, according to a new report from the American Lung Association. After the latest report, it was revealed that the district received an “F” grade for ozone pollution. There were 14 orange days which means unhealthy conditions for those of a sensitive nature. It can be especially bad for people with pre-existing respiratory problems.

Where does the air pollution in Washington DC come from?

The main source of Washington DCs polluted air is fine particulate matter or PM2.5. Dust from the demolition of existing buildings and the cement dust that is ever-present with new builds. Agricultural activities and smoke from wildfires and wood-burning stoves make a large contribution. As does black carbon or soot from the combustion of high-sulphur content fuels used in ships, trains and from factory emissions. Discharges from the thousands of vehicles that use the roads for their daily commute considerably contribute large amounts of pollutants through their exhaust systems. PM2.5 is also created through the abrasion between the tyres and the road surface and the brake discs/drums.

Air pollution in your local community depends mostly on local sources; however, some types of air pollution can travel many miles such as ozone and smoke from wildfires. Air pollution can vary by time of year depending on weather and seasonal sources such as woodstoves. The level of ozone can vary throughout the day because its production is dependent on ultraviolet light from the sun which is strongest during the early hours of the afternoon.

There are five main locations where air pollution data is collected by DOEE, located at Takoma Recreation Centre, McMillan Reservoir, Hains Point, River Terrace Site, and Anacostia Freeway. Not every site collects the same information, but the overall information is collected on ozone, particulate matter, carbon monoxide, sulphur dioxide, and nitrogen dioxide. The authorities no longer measure the levels of lead in the atmosphere because the levels are reducing on an annual basis and are all below the recommended levels, consistently.

Is Washington DC doing anything about improving the quality of its air?

The Air Quality Division of the local government department works to protect the health and welfare of District residents, visitors, and the natural environment by reducing the concentration of pollutants in the air. The Division issues permits, performs permit inspections and sees to the enforcement of laws, and monitors air quality while developing plans for its improvement.

With a few exceptions, motor vehicles powered by gasoline or diesel are not allowed to idle for more than three minutes while the vehicle is parked, stopped or standing.

In July 2020, Washington DC signed a memorandum with 15 other states committing themselves to phasing-out ALL fossil fuel-powered vehicles by 2050. Their aim is to reduce the numbers gradually with a reduction of at least 30 per cent by 2030.

The electric vehicle industry is primed for tremendous growth and nobody can afford to miss this opportunity to place clean transportation technology and infrastructure at the centre of the nation’s economic recovery. For this to be successful though, there needs to be many charging stations conveniently placed throughout the city. Without these back-up power sources, drivers will not have the confidence to use electric vehicles for fear of becoming stranded.

How is human health affected by the poor air quality in Washington DC?

90 per cent of total particle mass emitted from wildfires comprises fine particulate matter, or particles 2.5 microns or smaller in size (PM2.5), which poses the biggest threat to health. Due to their microscopic size, PM2.5 can penetrate deep into the lungs and into the bloodstream, ultimately settling into and impacting various parts of the body. Once PM2.5 penetrates this deeply, the body is unable to filter it out, which can create long-lasting inflammation.

Exposure to carbon monoxide can lead to visual and cognitive impairments, headaches, and nausea.

Lead exposure can cause damage to the nervous system, IQ loss, impaired learning and cognitive retention, and more.

Ground-level ozone can increase the risk of pre-eclampsia and pre-term birth during the first trimester, and particulate matter exposure has been linked to low birth weight and an increased risk of a child developing asthma later in life because particulate matter can travel into the placenta.

Ozone irritates the respiratory tract when you breathe it. It can cause wheezing and shortness of breath, chest pain; aggravate bronchitis, emphysema and asthma; reduce lung function and increase susceptibility to respiratory infections.

Even strong, healthy people can experience health implications from polluted air including respiratory irritation or breathing difficulties during strenuous exercise or outdoor activities. The risk of adverse effects depends on your current health status, the pollutant type and concentration, and the length of your exposure to the polluted air.

High levels of polluted air can cause some immediate effects, such as aggravated cardiovascular and respiratory illnesses. This in turn adds to stress to the heart and lungs as they have to work harder to keep the desired amount of oxygen supplied to the body. Cells within the respiratory system can soon become irrevocably damaged.

Carbon monoxide (CO) can also be a serious indoor air contaminant. Indoor sources include furnaces or boilers, kerosene heaters, wood-burning stoves and fireplaces, gas ranges, gas-powered appliances and space heaters, improper use of generators and grills inside and improperly vented car exhaust systems.

Carbon monoxide interferes with the body’s ability to absorb oxygen into the bloodstream. People with existing heart disease are particularly sensitive to health impacts from carbon monoxide. Exposures to it can result in reduced oxygen to the heart and cause chest pain.

What is the fuel known as E15? Will it help the situation in Washington DC?

E15 is a fuel blend consisting of 15 per cent renewable biofuel. It can immediately provide Americans with an easy way to lower their carbon footprint without sacrificing fuel efficiency or buying a new vehicle and it can significantly reduce transportation emissions immediately. E15 is home-grown, cleaner, and less expensive than regular petroleum. It’s compatible with almost all existing engines found in most cars and trucks, and it’s a promising opportunity for family farmers and rural communities.

E15 doesn’t require new cars or new infrastructure, making it accessible and affordable to everyone. It saves drivers money at the pump, typically between 3 to 10 cents less per gallon compared to E10 fuel, and it will help clean the air in densely populated urban communities such as Washington DC.

Independent research shows that biofuel blends reduce toxic vehicle emissions by up to 50 per cent. Researchers also found that introducing ethanol in cities around the world reduced benzene-related cancer by more than 20 per cent which leads to saving lives and reducing health care costs for people in congested, heavily-trafficked areas. Ethanol (E15) is 42 per cent cleaner than traditional gasoline and getting even cleaner with innovations in technology and sustainable farming.

The benefits of E15 reduce US dependence on foreign oil supplies and increase the demand for more home-grown grain which is used in the production of ethanol. E15 would provide some extra stability in the rural communities that grow the grain and help generate well-paid jobs and capital investments in the agricultural areas.

Biorefineries are exceptionally efficient and can quickly add capacity. Within a year of passing the Renewable Fuel Standard (RFS), US ethanol production jumped almost 30 per cent and it has almost doubled since then. If the demand for E15 grows, the US can sustainably meet it. Currently, there are over 2 billion gallons of ethanol capacity available.

Washington, D.C. air quality data attribution

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