Ultrafine Particles – An Update – What, Where, Why, Concern
Personal exposure to ultrafine particles (UFP) occurs every day while people are outdoors or in their homes, offices, and other indoor environments. Sources of indoor UFP are numerous and typically result from particular activities, such as cooking, cleaning, smoking tobacco products, or operating consumer appliances or some types of commercial imaging devices. Even though there is a plethora of outdoor UFP sources, including vehicle emissions and outdoor air pollution, studies suggest that indoor sources are greater than outdoor sources for a typical non-smoking suburban consumer (Wallace and Ott 2011).
Ultrafine particles are very small, typically less than 0.1 μm or less than 100 nanometers (or about 1/1000th of a human hair). By virtue of their size, they can be easily inhaled and travel deep into the human lung. Results of studies to date have indicated a strong correlation between UFP exposure and death from respiratory and cardiovascular illnesses, as well as a heightened allergic inflammation that can exacerbate asthma. The US Environment Agency (US EPA) reports that researchers estimate that thousands of elderly people die prematurely each year from exposure to fine particles. According to the American Academy of Pediatrics, children and infants are also very susceptible to health problems from exposure to many air pollutants (US EPA 2011a).