Air Quality
Chemical Components of PM and Their Biologic Effects
| Component | Major Subcomponents | Biologic Effects |
|---|---|---|
| Inorganic Compounds | Iron, vanadium, nickel, copper, platinum, siliceous materials, and others | Can trigger inflammation, cause DNA damage, and alter cell permeability by inducing production of reactive oxygen species |
| Organic Compounds | Many are absorbed onto particles; some volatile or semi-volatile organic species form particles themselves | Some may cause mutations, some may cause cancer; others can act as irritants and can induce allergic reactions |
| Biologic Origin | Viruses, bacteria, and their endotoxins (lipo-polysaccharides), animal and plant debris (such as pollen) and fungal spores | Plant pollens can trigger allergic responses in the airways of sensitive individuals; viruses and bacteria can provoke immune defense responses in the airways |
| Ions | Sulfate, nitrate, and acidity (H+) | Sulfuric acid, at relatively high concentrations, can impair mucociliary clearance and increase airway resistance in people with asthma; acidity may change the solubility and availability of metals and other compounds adsorbed onto particles |
| Reactive Gases | Ozone, peroxides, aldehydes | May adsorb onto particles and be transported into lower airways, causing irritation and injury to tissues |
| Particle Core | Carbonaceous material | Carbon induces lung irritation, epithelial cell proliferation, and fibrosis after long-term exposure |
(Health Effects Institute, April 2002)
