by Julia Ward PM2.5 is all around us, whether you know it or not. In general particulate matter, or PM, is the term for particles found in the air including dust, dirt, soot, and smoke. These particles can be suspended in the air for long periods of time. PM2.5 more specifically, is considered to be a small particle that is released into the air due to diesel and vehicle … [Read more...] about What is PM2.5?