Air pollution in the form of fine particles with diameters smaller than 2.5 microns, called PM 2.5, lodge in the lungs which can aggravate other conditions both immediately and long term –cutting months off of lives of those with comorbidities. The Air Quality Life Index (AQLI) group at the University at Chicago find that reducing the particulate air pollution to the WHO guideline would increase global average life expectancy by 2.2 years. AQLI says that this is comparable to the impact from quitting smoking.
PM2.5 is is fine particle matter, and when inhaled can have immediate health impacts: itchy, watery eyes, increased respiratory symptoms such as irritation of the airways, coughing or difficulty breathing and aggravated asthma. Long term health effects can result from both short-term and long-term exposure to particulate pollution. Exposure to particles can cause premature death in people with pre-existing cardiac or respiratory disease. Researchers are still working to identify which types and sources of particles are most hazardous to human health, but they have been making progress in that area recently.
Particle are either directly emitted or formed in the atmosphere. Directly-emitted particles come from a variety of sources such as cars, trucks, buses, industrial facilities, power plants, construction sites, tilled fields, unpaved roads, stone crushing, and burning of wood. Other particles are formed indirectly when gases produced by fossil fuel combustion react with sunlight and water vapor. Many combustion sources, such as motor vehicles, power plants, refineries, and wildfires both emit particles directly and emit precursor pollutants that form secondary particulates. Surprisingly, during 2020, the first year of the Covid-19 pandemic, when widespread lockdowns slowed the world’s economy, the global annual average particulate pollution (PM2.5) was largely unchanged from 2019 levels.
The U.S. Environmental Protection Agency, EPA, requires states to monitor air pollution to assess air quality and ensure that they meet minimum air quality standards. The US EPA has established both annual and 24-hour PM2.5 air quality standards (as well as standards for other pollutants). The annual standard established in 2012 is 12 µg/m³ (an AQI of 39). The 24-hr standard remained at 35 µg/m³ (an AQI of 99) and will remain unchanged. States had until 2020 to meet this PM2.5 health standard, but not all areas are in compliance. If you want to take a look at real time particulate pollution levels you can see what the monitors nearest your home are reporting. Note that the levels are reported in AQI (0-50 AQI is good air quality and 51-99 is moderate air quality), but the detail on many sites includes the PM2.5 levels. Long Park in Haymarket Virginia was reporting an AQI level of 19 as I was finishing this article. Long Park is about 3 miles from my house down route 15. The other site below that is Washington Street in San Francisco where I lived for about 20 years.
The wild fires that annually burn across the West (and many parts of the world) carry smoke and particulate pollution great distances, even to the east coast. Wildfires are becoming more frequent and destructive in an environment more and more shaped by mankind’s choices in a changing climate. Fine particulate matter, PM2.5, in wildfire smoke adversely impacts human health. Recent toxicological studies suggest that wildfire particulate matter may be more toxic than equal doses of ambient PM2.5.
"In epidemiological studies, it has been shown that PM2.5 from wildfire smoke can exacerbate a range of health problems including respiratory and cardiovascular issues."
So, if you want to take a look at real time particulate pollution levels you can see what the monitors nearest your home or any where else in the world are reporting at this link.