This article will focus first on the general composition of particulate matter (PM) outdoors and its origins. Then we switch to indoor formation and sources specifically related to animal care facilities.
What we know is particulate matter (PM) is composed of unseen particles made up of tiny pieces of solids and liquids found in the atmosphere. Some, such as dust, smoke, dirt, and soot are large or dark enough to be seen, while most is only visible using an electron microscope. Particulate matter, both indoors and outdoors, is categorized as:
- Coarse PM – PM10, which is 10 microns or smaller in diameter and inhalable, mostly created by the breakup of larger debris particles.
- Fine PM – PM2.5, which is 2.5 microns or smaller in diameter and created by further breakup of PM10 as well as material and gasses created by worksites, etc. and easily inhalable into the lungs and beyond.
- Ultrafine PM – PM below 100 nanometers (nm) in diameter and made mostly of particles created from sulfates and organic matter in the first stage of nucleation (evolution of a gas to a particle).
According to European studies, the makeup of particulate matter (PM) outdoors, of the course and fine PM categories, also comes from sulfates and organic matter, with carbon emissions rated as the most serious airborne threat, surpassing even tobacco smoke as the deadliest.
Ultrafine particulate matter (PM) consists of only a few percentage points in the overall mass of PM, but makes up 90% of the total particulate numbers found in outdoor air. Ultrafine PM comes in many sizes and shapes and can be made of hundreds of different chemicals. These particles cross vast oceans, multiplying with exposure to ocean moisture and humidity, and combining with sand and dust particles, are carried on the prevailing winds and storms.
The more advanced countries of the world have made much improvement to outside air control of particulate matter (PM) to mitigate industrial and other population-produced pollutants that partner with PM and pose a threat to human life longevity. In addition, according to Joel Schwartz, Professor of Environmental Epidemiology at Harvard on PM2.5*, outdoor air mixed with burning fossil fuels caused recorded deaths of 350,000 in the US alone. The NIH/National Library of Medicine published estimated 10.2 million deaths globally for the same period.
The World Health Organization has acknowledged that even with the improvements to outdoor air made in developed countries, the high levels of outdoor particulate matter (PM) and pollutants pose a significant negative effect on the world’s overall health and lifelong longevity.
The creation of particulate matter outdoors also comes from construction sites, unpaved roads, plowed agricultural fields, smokestacks, and fires, both wild as well as those created for recreational use and heating purposes. Add to that particulate matter (PM) created in the atmosphere due to reactions involving chemicals such as sulfur oxides and nitrates emitted from industrial sources and combustion engines, plus the new electric vehicle (EV) wear on road surfaces (Electric vehicles, due to heavier chassis mainly from the battery, create more wear and tear on both tires and road surfaces, which produces PM from worn tires and road surfaces, especially in dense urban environments).
We will never be able to completely eradicate particulate matter (PM) from the outside atmosphere. We can only reduce some of the most notorious and offensive sources. Advances in technology and the public’s improved awareness of the threat to humanity will be our major tools in the fight for better health and longer, more productive lives.
However, protections and major reductions in particulate matter (PM) formation indoors can be achieved, today!!!
Tune in next time for indoor particulate matter (PM) sources specific to animal care and grooming and what it may be composed of.
-The Professor
*Harvard TH Chan School of Public Health, February 9th 2021