[UPDATE: FNSB 2009 Symposium Summary file is corrupted; assess the original file: 2009 Symposium Summary (recovered).]
From FNSB 2009 Symposium Summary, pp 5-6
Two presentations were given on the health effects of PM 2.5. The first, by Dr. Lori Verbrugge of the Alaska Division of Public Health, explained that fine and ultra fine particles (i.e., PM 2.5) behave like a gas—they penetrate indoors from outside air, they adsorb toxic compounds, and they penetrate deep into the lung. Groups who are at most risk from exposure to elevated concentrations include children, the elderly, people with heart and lung disease, people with weakened immune systems, and people who work outdoors. Children are more susceptible because they breathe more air per body weight than adults, they tend to be active, they mouth-breathe when active (i.e., crying), and their lungs are still developing. An additional concern is that their immune and brain defenses are not fully formed. Older adults lose immune and respiratory defenses with aging; they may also have lung injuries, circulatory illness, diabetes, etc., which increases their vulnerability to PM 2.5.
Health effects from short-term exposure can include eye, nose, throat and lung irritation, headache, nausea, aggravated asthma, acute respiratory symptoms, and increased risk of heart attack. Health effects of chronic exposure to elevated PM 2.5 can include inflammation of respiratory membranes, bronchoconstriction, impaired respiratory defense, decreased heart rate variability, and accumulation of particles in the lung. The consequences of chronic exposure are increased hospital admissions and ER visits, chronic bronchitis, reduced lung capacity, increased cardiopulmonary mortality, reduction in life expectancy, and increased risk of lung cancer.
Dr. Verbrugge said the literature was very clear and consistent about the health effects of PM 2.5 and cited over 20 separate studies that consistently showed an increase in mortality associated with long-term particulate exposure. Collectively, the studies showed a 6–17% increase in relative mortality with each 10 microgram per cubic meter of PM 2.5 exposure. She said the available data showed there is increased mortality with short-term exposure to PM 2.5 concentrations that are less than 20 μg/m3, which is considerably below the new “health-based” 24-hour standard of 35 μg/m3. Overall, she said it is estimated that elevated PM 2.5 levels are responsible for 60,000 deaths per year in the US.
The second presentation, by Rachel Kossover, MPH, RD, also from the Alaska Division of Public Health, outlined a study she is conducting to evaluate whether there is a relationship between daily PM 2.5 concentrations and local hospitalization rates in Fairbanks. That study, however, has just been started and results are not expected until next summer. When completed, it should provide the first insight into how relative risk varies within Fairbanks in relation to age, sex, rurality, and ethnicity.
[Results now available: State of Alaska Epidemiology bulletin on the association between PM 2.5 and Fairbanks hospital admissions 8/30/2010; State of Alaska Department of Health and Human Services fact sheet on the 8/2010 bulletin; and FDNM article on the 8/2010 State of Alaska Epidemiology study, 8/30/2010.]