<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">particulate matter</topic></authority><related type="broader"><topic>residue materials</topic></related><variant type="other"><topic>PM</topic></variant><variant type="other"><topic>matter, particulate</topic></variant><variant type="other"><topic>particle pollution</topic></variant> <note xml:lang="en"><![CDATA[ Extremely small particles and droplets suspended in air. They may include organic chemicals, acids, metals, and dust or soil particles. Also known as particle pollution, particulate matter is used as a measure of air pollution. The EPA  groups inhalable pollutants which pass through the throat and nose and enter the lungs into two categories: “inhalable coarse particles” (between 2.5 micrometers and 10 micrometers in diameter); and “fine particles” (2.5 micrometers in diameter and smaller).  ]]></note></mads>