fine particulate matter (PM2.5) and mortality...

Research studies on wood smoke and other air pollution.

fine particulate matter (PM2.5) and mortality...

Postby Wilberforce » Wed Jan 07, 2015 1:30 pm

Associations between Long-Term Exposure to Chemical Constituents of Fine Particulate Matter (PM2.5) and
Mortality in Medicare Enrollees in the Eastern United States
Chung et al

Background: Several epidemiological studies have reported that long-term exposure to fine particulate matter (PM2.5) is associated with higher mortality. Evidence regarding contributions of PM2.5 constituents is inconclusive.

Objectives: We assembled a dataset of 12.5 million Medicare enrollees (=65 yrs) to determine which PM2.5 constituents are: 1) associated with mortality controlling for previous-year PM2.5 total mass (main effect); and 2) elevated in locations exhibiting stronger associations between previous-year PM2.5 and mortality (effect modification).

Methods: For 518 PM2.5 monitoring locations (Eastern US, 2000-2006), we calculated monthly mortality rates, monthly long-term (previous 1-year average) PM2.5, and 7-year averages (2000-2006) of major PM2.5 constituents [elemental carbon (EC), organic carbon matter (OCM), sulfate (SO4=), silicon (Si), nitrate (NO3-), and sodium (Na)] and community-level variables. We applied a Bayesian hierarchical model to estimate location-specific mortality rates associated with previous-year PM2.5 (model level 1) and identify constituents that contributed to the spatial variability of mortality, and constituents that modified associations between previous-year PM2.5 and mortality (model level 2), controlling for community-level confounders.

Results: One standard deviation (SD) increases in 7-year average EC, Si, and NO3- concentrations were associated with 1.3% [95% posterior interval (PI): 0.3, 2.2], 1.4% (95% PI: 0.6, 2.4), and 1.2% (95% PI: 0.4, 2.1) increases in monthly mortality, controlling for previous-year PM2.5. Associations between previous-year PM2.5 and mortality were stronger in combination with 1-SD increases in SO4= and Na.

Conclusions: Long-term exposures to PM2.5 and several constituents were associated with mortality in the elderly population of the Eastern US. Moreover, some constituents increased the association between long-term exposure to PM2.5 and mortality. These results provide new evidence that chemical composition can partly explain the differential toxicity of PM2.5.
• The Surgeon General has determined that there is no safe level of exposure to ambient smoke!

• If you smell even a subtle odor of smoke, you are being exposed to poisonous and carcinogenic chemical compounds!

• Even a brief exposure to smoke raises blood pressure, (no matter what your state of health) and can cause blood clotting, stroke, or heart attack in vulnerable people. Even children experience elevated blood pressure when exposed to smoke!

• Since smoke drastically weakens the lungs' immune system, avoiding smoke is one of the best ways to prevent colds, flu, bronchitis, or risk of an even more serious respiratory illness, such as pneumonia or tuberculosis! Does your child have the flu? Chances are they have been exposed to ambient smoke!
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