SILVER LINING Pollution Percentage, Degree, and AQI Decrease

Silver Lining: When something great comes out of something bad! I asked the children to describe their own silver lining during the Covid-19 crisis. Their answers were so exciting to hear: I get to spend more time with my family; I get to create art; I get to bike; I get to play outside; I get to play baseball with my dad; I get to play games with my older brother; I get to see my old friend from Tunisia; silver linings are not always positive.

The coronavirus pandemic is the “largest scale experiment ever” into global air quality.

Nitrogen dioxide (NO2): Nitrogen dioxide is a toxic gas produced from car engines, power plants and other industrial processes and increases respiratory illnesses such as asthma. The World Health Organization describes NO2 as “a toxic gas which causes significant inflammation of the airways” at concentrations above 200 micrograms per cubic meter. PM2.5 = fine particulate matter is another measurement of air pollution. 

While not a greenhouse gas itself, the pollutant originates from the same activities and industrial sectors that are responsible for a large share of the world’s carbon emissions and that drive global heating.


Benefits of reduction in NO2:

1. Reduce the spread of asthma

2. Reduce viruses because NO2 inflames and lowers immunity

3. Reduce pathogens (bacteria, virus, and other microorganisms) which cause disease

4. Prevents pollution caused by reducing the need to harvest new raw materials

5. Saves energy

6. Reduces gas emissions that contribute to global climate change

7. Helps sustain the environment for future generations

8. Saves money

9. Reduces the amount of waste that will need to be recycled or sent to landfills and incinerators

10. Allows products to be used to their fullest extent


Conversion of micrograms (mcg) to meters (m)


1 cubic centimeter cm^3 = 1,000 micrograms mcg

1 cubic meter m^3 = 1,000,000 cm^3  

1 m^3 = 1,000,000,000 mcg

so 200 mcg/ 1m^3 = 200 mcg/1,000,000,000 mcg


We determined that the ratio of NO2 levels cannot be greater than 1 in 5,000,000 parts.


The coronavirus pandemic is shutting down industrial activity and temporarily slashing air pollution levels around the world, satellite imagery from the European Space Agency shows. Readings from ESA’s Sentinel-5P satellite show that over the past six weeks, levels of nitrogen dioxide (NO2) over cities and industrial clusters in Asia and Europe were markedly lower than in the same period last year.


I had the children shade in the percentage decrease in each major city around the globe and indicate the complement (this is the remaining pollution) on a bar graph split into 10ths. For example, Los Angeles decreased its pollution by 31% and the complement was 69% remaining pollution.


I had the children do the same with circle graphs split into 10ths, each 10% equal to 36 degrees and then estimate the total degree decrease.


Rome was the most interesting change since the pollution went up by 30%.


25% Lower NO2 Levels across China


40% Lower NO2 Levels


Smoke from factories in Northern Italy gets trapped against the Alps Mountains.

Rome had 10% increase in NO2 levels due to people using heating systems more than normal


Two weeks into a national lockdown in India, residents of Jalandhar in Punjab, India woke up to an incredible sight in the distance: the Dhauladhar mountain range in Himachal Pradesh, the Himalayas. The peaks, which are over 120 miles away, had not been sighted on the Punjab horizon for almost 30 years. The country has 21 of the 30 worst polluted areas in the world, according to an IQAir world air quality report.


More than 85 cities across India have seen a drop in air pollution since the country started its nationwide lockdown, according to the Central Pollution Control Board.


I had the children determine the positive or negative difference in the Air Quality Index. A reduction in AQI is good and an increase is bad. I encouraged the children to think of subtraction as adding. Find a friendly number: for example, 103 minus 98 equals 5 since 98 is 2 from 100 and 103 is 3 from 100; adding 2 + 3 = 5. 


Data from the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite shows a substantial drop in atmospheric nitrogen dioxide, according to NASA.  

Pollution_Percent_and_AQI_Decrease.pdf15.29 MB
Pollution_Percent_Degree_and_AQI_Decrease.pdf17.08 MB