Hello, Naman, and thank-you for posting your questions regarding air pollution. Yes, the lockdowns especially in the spring of 2020 really did produce observable improvement in health; however, the world has gone back to producing as much air pollution as it can.
I moved from Philadelphia, where I lived, in 1973 because I became aware that the air pollution there was causing me chronic health problems. I returned to Tucson, AZ where I was born and raised because my parents had allergies and they believed Tucson had cleaner air than other industrial areas. When they moved there in 1953 the population of Tucson was only about 35,000. After that Tucson was rated as the fastest growing city in the USA throughout the 50s, and it continues to grow at a high rate to the present.
In the mid to late 70s I visited southern California several times and found the LA basin was so polluted that I had severe conjunctivitis and respiratory issues the whole time until I left the basin. I moved to San Francisco in the late 70s and moved back to Tucson to get away from the air pollution I experienced in San Francisco.
Throughout most of my life in Tucson I experienced 2 respiratory inflammation events every year I lived there. I spent my 40s studying at the university there. My last year at the university there I turned 53, and I had many inflammatory events. So, I took the degrees I could (4). As soon as I graduated I left Tucson for the Inyo National Forest, where I camped for 2 years.
I found the Inyo National Forest much better for my health. However, even though the Inyo National Forest is remote and has the lowest population density anywhere in the continental USA; nonetheless I found I had to move roughly every 2 months due to the arising of a collection of autoimmune reactions that I have come to recognize as reactions to air pollution. I found to get relief all I needed to do was move changing my elevation by 2,000 feet, and I would continue to rise in elevation through the summer, then decrease my elevation from September on until the deepest part of winter, then begin to rise in elevation again as spring and summer arrived.
I spent most of the next 10 years living in the national forest. In 2010 I moved to Prescott, AZ, USA believing that since Prescott was surrounded by national forest and it had low industrial activity and low population, I reasoned that it should have excellent air quality, and I was tired of running away from my health problems, so I stayed there for 10 years. Nonetheless, 6 months after I moved there I had been in the ER 6 times in my first 6 months there due to a range of inflammatory conditions, and after 6 months I went for a physical and was told I was "Full-on diabetic with a blood sugar level 2.5x normal, and high blood pressure and high cholesterol levels."
It just so happens that my most recent physical was almost exactly a year earlier, and conducted in Tucson, where the doctor told me, “Mr. Brooks you are in excellent health, and you have the cardio vascular system of an athlete.”
So, at that point I had suspected that my recent health issues were due to living in Prescott, but I couldn’t understand why. And, my health continued to decline there year after year. I was confused to understand my decline in health when Prescott seemed to have such good air quality. However, I have since come to realize that air pollution is global, which means no place on the planet has adequately clean air; nonetheless, we can mitigate for global air pollution. The atmosphere mitigates for air pollution, but chemical reactions are temperature dependent, so this explains why I had to reduce my elevation as the ambient temperatures dropped after summer. Also, distance from pollution sources also helps, which explains why I did better the further I got from the major cities. And, examining a map of central Arizona I could see that Prescott is only 50 air miles north of Phoenix, AZ and Phoenix is rated by the American Lung Association as the US city with the 7th worst air quality, and the prevailing surface winds blow north from Phoenix right over Prescott.
After many trips to the ER over the years living in Prescott, I finally decided to start taking antihistamines for my allergies. I discovered the next day after starting taking antihistamines that my blood sugar was consistently lower, so I kept taking antihistamines while living in the Prescott area. Then 3 years and 8 months ago I was diagnosed with COPD, never having been a smoker. That is when I bought an air purifier, which began my recovery from not only COPD, but high blood pressure and diabetes. I even lost 50lbs I had gained when I moved to Prescott with no change in my diet.
So, clearly air pollution can be mitigated for by the use of air purifiers; however, one has to realize that HEPA only air purifiers only remove about 25% of the air pollution. Most air purifiers have an optional activated charcoal pre-filter, which is necessary for removing some of the gasses that are associated with air pollution. Nonetheless, the combination of HEPA plus activated charcoal only removes about ½ the air pollution, because there are other gasses contained in air pollution that are not effectively removed by activated charcoal; however, most of those gasses are highly attracted to water, so using a combination of a humidifier plus a dehumidifier effectively removes those gasses.
So, now that we understand air pollution is a serious problem, and the cities are producing it, and it is a global problem, but humidity is a factor in removing air pollution, and atmospheric chemistry helps mitigate for air pollution, then we could examine global wind patterns to understand the best, and worst places to live. If you examine a satellite map of air pollution you will find that most of the global air pollution is produced in the northern tropics between the Atlantic side of Africa through the Middle East, through Asia to the Pacific Ocean. And, knowing wind patterns in the northern hemisphere move west to east, so living along the west coast of the continents of the northern hemisphere; or, since winds in the southern hemisphere move east to west, then the east coast of the continents of the southern hemisphere is best. Also, volcanoes and wildfires emit far more air pollution than humans do, even globally, so you won’t want to be down wind of either volcanoes or wildfires. Also, the combination of humidity and salt significantly mitigates for some air pollution, therefore living by the ocean helps a great deal. However, having air purifiers powered by solar panels might be critical for your health, as it is for me.
This last spring I moved away from Prescott to Flagstaff, AZ to get further away from the pollution stream from Phoenix, and I found significantly improved health; however, Flagstaff is at the conjunction of 2 major highways, so I moved 25 miles away into the National Forest, where I have found even better health. Nonetheless, living in a national forest in the Southwestern USA during a 3 year drought which has produced record wildfires for the last 3 years has been a significant issue. Nonetheless, my air purifiers powered by solar panels, and the alternator on my engine, and a backup generator have allowed me to survive two summers of record wildfires in Flagstaff.
I know this was a long reply, but I hope it helps you and others.
