A Breath of Fresh Air
Since January, many cities around the world have been shutting down to slow the spread of coronavirus. In Philadelphia, the order to work from home issued by Governor Tom Wolf has forced all non-essential workers to remain home, which has been very disruptive to businesses and many people’s daily lives. However, the order is thought to have had a positive impact on the city’s air pollution.
While the environment is likely not top of mind at the moment, working from home is one way to reduce individual carbon footprints. Eliminating or reducing commutes eliminates emissions from cars, trains, or other transportation methods that may rely on fossil fuels.
The 2018 American Community Survey estimated that 400,000 people drive to work every morning in Philadelphia. With the recent orders to close all non-essential business and for people to stay at home in Philadelphia and the surrounding counties, that number has dramatically dropped. With it, air pollution is expected to improve in the city. Already, the daily Air Quality Index (AQI) released by the EPA shows that Philadelphia has seen the best air quality of any March in the past decade.
The AQI is a measure of air quality that accounts for several different pollutants, weather conditions, and pollutant emissions sources, such as cars that run on fossil fuels. Philadelphia’s air quality in the spring tends to undulate between “good” and “moderate” conditions, but this March there have been significantly more good air quality days than moderate ones.
Air quality index for Philadelphia, March, 2010-2020. March 2020 had more good air quality days than the same time period for the previous decade, with 29 good air quality days and only 2 moderate air quality days. Most of the good air quality days in Philadelphia in March, 2020 occurred after non-essential businesses were ordered to close (Data source: U.S. EPA AirData).
Lockdowns Clear the Air
In other parts of the world, the decrease in air pollution is detectable from space.
NASA satellite images show that the concentrations of nitrogen dioxide (NO2), an air pollutant caused by combustion, have significantly dropped over China in January and February 2020 compared to the same time the year before.
NASA images show nitrogen dioxide (NO2) concentrations over Wuhan, the city where the coronavirus originated, have dropped significantly compared to their concentrations from the same time the year before. This reduction in NO2 is due to the drop in fossil fuel combustion as electricity demand has declined and transportation has been restricted to contain coronavirus (NASA Earth Observatory images by Joshua Stevens, using modified Copernicus Sentinel 5P data processed by the European Space Agency (ESA)).
This drop in air pollution is the result of transportation restrictions and decreased demand for energy from combustion power plants. According to the Centre for Research on Energy and Clean Air, these restrictions impacted two of the largest sources of nitrogen dioxide in China, causing a 36% decrease in coal consumption in February, and a 70% decline in domestic flights. Reported along with this was a 21.5% increase in good air quality days in February in the region compared to the year before.
Italy, which has also implemented strict quarantine measures, has seen a similar improvement in nitrogen dioxide levels. After officials placed the country on lock down, including restrictions on transportation, ESA satellites detected a noticeable decrease in nitrogen dioxide.
However, Li Shuo, a climate policy advisor for Greenpeace East Asia, notes that air quality improvements from decreased economic activity may be short lived. Because the improvements in air quality have been linked to economic disruption, it is likely that once the threat of coronavirus passes, these areas will rapidly increase their economic activity, and with it their production of pollutants like nitrogen dioxide.
Another Public Health Hazard
Air pollution poses a significant threat to public health. The World Health Organization estimates that 4.2 million people die prematurely each year as a result of exposure to air pollution. Marshall Burke, an assistant professor at Stanford’s Department of Earth System Sciences, estimated that this recent improvement in air quality due to the coronavirus containment measures in China may have saved between 1,400 - 4,000 children under five and 51,700 - 73,000 adults over seventy.
Air pollutants like nitrogen dioxide that are typically abundant in large economic hubs like China harm human health because they are respiratory irritants. Short term inhalation of pollutants like nitrogen dioxide can irritate the respiratory system and exacerbate respiratory diseases such as asthma. Studies have found that long term inhalation of pollutants from emissions or smoking can cause one to develop asthma or become more susceptible to respiratory infections.
Because the coronavirus pandemic is only a recent development, no large scale studies have been conducted yet to determine if breathing polluted air increases one’s susceptibility to the coronavirus.
Looking to the Future of Air Pollution
While this period of working from home has done wonders for our air quality, humans are still social creatures, so a totally remote workforce is unlikely in the future. Collaborating with coworkers through video chat software will never be the same as meeting in person.
Even though we are in a dark time, we can learn from it. People around the world are appreciating the cleaner air they are experiencing. Perhaps when our lives return to normal, we can work to maintain this good air quality year-round.
The sudden dependency on technology we are experiencing in order to work from home will no doubt spur improvements that could make working from home easier and more commonplace. In turn, commutes and travel that depend on fossil fuels could be reduced for a significant part of the workforce. Those who have experienced how a global crisis can disrupt supply chains may decide to buy locally in the future, which, like working from home, reduces fossil fuels spent having goods shipped from around the world. Others thinking more about their direct impact on air pollution may choose to use public transportation if they return to their offices or opt for renewable energy that produces fewer emissions.
Even if people do not take individual action, hopefully they at least become more aware of how air pollution may impact their daily life and health.
Article by Allison Day, intern, Boyer Sudduth Environmental Consultants, April 2020.
