Deposition of Ultrafine Particles Increases in Lungs of People with Asthma
The dose of particles that reaches the lungs determines the pulmonary response to inhalation.
A group of researchers at the University of Rochester is studying the effect of ultrafine particles, those with a diameter less than 100 nanometers, on human health.
They hypothesize that ultrafine particles may contribute to the health effects of particulate matter because of their high surface area, oxidant capacity, ability to evade the macrophage defense system, and propensity for inducing pulmonary inflammation.
Earlier studies have shown that patients with chronic obstructive pulmonary disease have enhanced deposition of fine and ultrafine particles, and that fine particle deposition is increased in people with asthma. This is the first study to investigate the deposition of ultrafine particles in the lungs of subjects with mild asthma.
The study found that deposition of ultrafine particles at rest and during exercise was greater in people with asthma than in healthy subjects.
Researchers conclude: “People with asthma have a higher respiratory dose of UFP [ultrafine particles] for a given exposure, which may contribute to their increased susceptibility to the health effects of air pollution.”
Chalupa, DC, Morrow, PE, Oberdörster, G, Utell, MJ, and Frampton, MW. Ultrafine Particle Deposition in Subjects with Asthma. Environmental Health Perspectives 2004;112:879-882.
The National Institute for Environmental Health Sciences [ehp.niehs.nih.gov/docs/allpubs] offers the full article online.
