CARB Hosts Symposium on Particulate Matter

The California Air Resources Board will host a symposium on Feb. 26th on the science behind the methodology used to estimate premature deaths in California that are related to exposure to particulate matter (PM). Scientists from academic institutions and government agencies have been invited to participate. Topics to be discussed include scientific findings regarding the association between PM2.5 exposure and premature death, criteria for selecting a concentration-response function for making estimates of PM2.5-related deaths in CA, how uncertainties should be addressed, and whether we can differentiate the effects of PM2.5 from specific sources.

EPA: 31 Areas Violate 24-Hour Fine Particle Standards

Thirty-one areas across the country have been designated as not meeting the EPA's standards for fine particulate matter (PM 2.5). The final designation was based on previous air quality data used to identify nonattainment zones.

Using the 2006 to 2008 data, 91 U.S. counties that were identified as nonattainment in December 2008 are now meeting the standards. The new data also showed that four new counties in three states are violating the daily PM 2.5 standards, the annual PM 2.5 standards, or both. EPA will work with these four counties to evaluate air monitoring data and other factors to make final designations by early 2010.

Nonattainment areas include counties with monitors showing violations of the standards and the nearby areas that also contribute to that violation. Affected states and tribes will be required to take steps to reduce the pollution that forms fine particles. The majority of U.S. counties and tribal lands are meeting these standards, but will need to continue working to maintain clean air.

In 2006, EPA strengthened the 24-hour fine particle standards from 65 micrograms per cubic meter to 35 micrograms per cubic meter of air to protect public health. Nationwide, monitored levels of fine particle pollution fell 19 percent from 2000 to 2008. Fine particles can either be emitted directly from power plants, factories, and motor vehicles, particularly diesel trucks and buses, or they can form in the atmosphere from reactions of sulfur dioxide and nitrogen oxides.

Click here to view Final Designation Comparison for 24-Hour Fine Particle (PM 2.5) Standards

Air Pollution Study Hails Beijing Taxi Drivers

The September issue of Environmental Health Perspectives published a study using Beijing Taxi drivers as study participants. Drivers were evaluated at three different times periods, with each examination associated with a different level of particulate pollution. One time period was during the 2008 Beijing Olympics when levels of PM2.5 were less than half of the average exposure levels experienced before or after the games. This is one of the first reports to document if any health effects were achieved by China's major air pollution clean-up effort prior and during the Olympics.

The study showed a relationship between increased exposure to fine particulate matter and a decrease in cardiac function (or heart rate variability - HRV). Author Shaowei Wu stated "A comparison of raw five-minute HRV indices indicated that the low PM2.5 exposure period (during the Olympic Games) was associated with relatively high HRV, while higher PM2.5 exposures (before and after the Olympic Games) were associated with relatively low HRV."

See Article: Association of Heart Rate Variability in Taxi Drivers with Marked Changes of Particulate Air Pollution in Beijing in 2008

Tunnels Trap Toxic Cocktail of Particulates

A recent study by the Queensland University of Technology's International Laboratory for Air Quality and Health measured the concentration of ultrafine particulate matter found in the M5 East tunnel located in Sydney, Australia. Their findings show that a tunnel has the potential to trap levels of pollution so high as to be dangerous to travelers - particularly those driving older, less airtight vehicles, convertibles and motorcycles.

The effects of breathing in high concentrations of ultrafine particulate can range from minor respiratory problems to a heart attack in people with existing heart trouble. The study analyzed a large body of data and showed that at times, the levels were up to 1000 times higher than average urban ambient conditions.

Princeton Study Found Thousands Killed Each Year from Air Pollution

A recent study by a team of researchers from Princeton University has found that thousands of people around the world meet pre-mature death annually due to air pollution composed of microscopic particles. They estimate that 380,000 people are impacted and die due to particle pollution composed of diesel emissions, smoke from coal-fired power plants, as well as natural dust particles that mix with the toxins.

Of concern is the amount of air pollution that originates in other countries and is than carried by air currents to another part of the globe - branded "transcontinental pollution". The study sites as an example a dust plume from African deserts and fog pollution from Europe, which then converge on India.

Fine particle pollution (less than 2.5 microns in diameter) impacts health by causing breathing problems, irritation and becoming embedded within the lungs. The particles can also enter the bloodstream and damage arteries.

The study was published in Atmospheric Environment.

Court Rejects Challenges Against EPA Air Pollution Standards

On Tuesday, June 7th, the U.S. Court of Appeals for the District of Columbia Circuit rejected nearly all challenges to the EPA's standards for reducing emissions of fine particulate matter (soot). The challenge was brought by nine cities, ten power industry groups, and three states. The ruling to enforce more stringent standards will effect over 200 countries throughout the US.

Read the original ruling