Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Reducing fine particulate air pollution cuts mortality risk

16.03.2006


Investigators who extended the Harvard Six Cities fine particulate air pollution study by eight years found that reduced levels of tiny particle pollution during this period lowered mortality risk for participants.



The results appear in the second issue for March 2006 of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

The findings of the original Harvard Six Cities study (1979 to 1990) revealed an association between levels of fine particulate matter pollution and mortality risk. The new study, which was conducted from 1990 to 1998, reports on this later period of reduced air pollution concentration.


Francine Laden, Sc.D., of Channing Laboratory in Boston, Massachusetts, and three associates found that the largest drops in adjusted mortality rates were in cities with the greatest reduction in fine particulate air pollution (PM2.5). The investigators’ findings remained valid even after setting controls for the general increase in adult life expectancy that occurred in the U.S. during both study periods (1979 to 1989 and 1990 to 1998).

"This reduction was observed specifically for deaths due to cardiovascular and respiratory disease and not from lung cancer, a disease with a longer latency period and less reversibility," said Dr. Laden.

The study population consisted of 8,096 white participants residing in Watertown, Massachusetts; Kingston and Harriman, Tennessee; St. Louis, Missouri; Steubenville, Ohio; Portage, Wyocena, and Pardeeville, Wisconsin; and Topeka, Kansas. The average age of participants at the start of the original study was 50, with women comprising 55 percent of the cohort.

"Current smoking on enrollment ranged from 33 percent in Topeka and 40 percent in Watertown, and former smoking ranged from 21 percent in Harriman to 25 percent in both Topeka and Watertown," said Dr. Laden.

The annual mean concentration of PM2.5 (fine particulate matter) declined during the eight-year study period by 7 micrograms per cubic meter of air per decade in Steubenville, 5 micrograms in St. Louis, 3 micrograms in Watertown, 2 micrograms in Harriman, 1 microgram in Portage and less than a microgram in Topeka.

The improved mortality relative risk due to decreased PM2.5 during the second study period, as compared to the first, was 0.73.

In an editorial on the article in the same issue of the journal, Bert Brunekreef, Ph.D., of the Institute for Risk Assessment Science at the Universiteit Utrecht and the University Medical Center in Utrecht, The Netherlands, wrote:

"The investigators show that the city-specific reduction of PM2.5 was associated with a reduction in mortality rates. The reason why this is so important is that, until now, it was not clear whether the cohort studies were showing effects that resulted from lifetime cumulative exposure. If so, late changes in exposure would have little, if any, effect on survival. These new findings suggest another dynamic--namely that recent exposures do matter. This would be consistent with pollution affecting primarily a dynamic "pool" of susceptible individuals whose susceptibility itself may to some extent have been increased by lifelong, cumulative pollution exposure. We do know that smoking cessation leads to reductions in respiratory, cardiovascular and lung cancer risks, with different lags. The findings in this study, which show no effect on pollution reduction on lung cancer and the strongest effects on respiratory and cardiovascular mortality reduction, seem to show a similar pattern. The practical implication is that pollution reduction, even beyond the relatively low levels that have been achieved in the past half-century, will lead to public health benefits."

Dr. Brunekreef also highlights the study’s limitations: the size of the study population was relatively small; some effects of clear medical importance were not considered statistically significant; and the PM2.5 concentrations during the second phase of the study were estimated. Moreover, because participants in the last phase were not interviewed regularly, potential variables--such as a change in smoking habits--may not be reflected in the data. He concluded that additional studies are needed.

Suzy Martin | EurekAlert!
Further information:
http://www.thoracic.org

More articles from Health and Medicine:

nachricht Electrical 'switch' in brain's capillary network monitors activity and controls blood flow
27.03.2017 | Larner College of Medicine at the University of Vermont

nachricht Laser activated gold pyramids could deliver drugs, DNA into cells without harm
24.03.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>