September 5th, 2011:

Particle Pollution and Your Health.htm http://cfpub.epa.gov/airnow/index.cfm?action=particle_health.page1#2

Airborne particles, the main ingredient of haze, smoke, and airborne dust, present serious air quality problems in many areas of the United States. This particle pollution can occur year-round and it can cause a number of serious health problems, even at concentrations found in many major cities.

What is particle pollution?

*Photo courtesy of the Weather Channel.

Particle pollution is a mixture of microscopic solids and liquid droplets suspended in air. This pollution, also known as particulate matter, is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, soil or dust particles, and allergens (such as fragments of pollen or mold spores).

The size of particles is directly linked to their potential for causing health problems. Small particles less than 10 micrometers in diameter pose the greatest problems, because they can get deep into your lungs, and some may even get into your bloodstream. Exposure to such particles can affect both your lungs and your heart. Larger particles are of less concern, although they can irritate your eyes, nose, and throat.

Small particles of concern include “fine particles” (such as those found in smoke and haze), which are 2.5 micrometers in diameter or less; and “coarse particles” (such as those found in wind-blown dust), which have diameters between 2.5 and 10 micrometers.

Are you at risk from particles?

People with heart or lung disease, older adults, and children are considered at greater risk from particles than other people, especially when they are physically active. Exercise and physical activity cause people to breathe faster and more deeply and to take more particles into their lungs.

People with heart or lung diseases such as coronary artery disease, congestive heart failure, and asthma or chronic obstructive pulmonary disease (COPD)are at increased risk, because particles can aggravate these diseases. People with diabetes also may be at increased risk, possibly because they are more likely to have underlying cardiovascular disease.

Older adults are at increased risk, possibly because they may have undiagnosed heart or lung disease or diabetes. Many studies show that when particle levels are high, older adults are more likely to be hospitalized, and some may die of aggravated heart or lung disease.

Children are likely at increased risk for several reasons. Their lungs are still developing; they spend more time at high activity levels; and they are more likely to have asthma or acute respiratory diseases, which can be aggravated when particle levels are high.

It appears that risk varies throughout a lifetime, generally being higher in early childhood, lower in healthy adolescents and younger adults, and increasing in middle age through old age as the incidence of heart and lung disease and diabetes increases. Factors that increase your risk of heart attack, such as high blood pressure or elevated cholesterol levels, also may increase your risk from particles. In addition, scientists are evaluating new studies that suggest that exposure to high particle levels may also be associated with low birth weight in infants, pre-term deliveries, and possibly fetal and infant deaths.

How can particles affect your health?

Particle exposure can lead to a variety of health effects. For example, numerous studies link particle levels to increased hospital admissions and emergency room visits and even to death from heart or lung diseases. Both long- and short-term particle exposures have been linked to health problems.

Long-term exposures, such as those experienced by people living for many years in areas with high particle levels, have been associated with problems such as reduced lung function and the development of chronic bronchitis and even premature death.

Short-term exposures to particles (hours or days) can aggravate lung disease, causing asthma attacks and acute bronchitis, and may also increase susceptibility to respiratory infections. In people with heart disease, short-term exposures have been linked to heart attacks and arrhythmias. Healthy children and adults have not been reported to suffer serious effects from short-term exposures, although they may experience temporary minor irritation when particle levels are elevated.

What are the symptoms of particle exposure?

Even if you are healthy, you may experience temporary symptoms, such as irritation of the eyes, nose, and throat; coughing; phlegm; chest tightness; and shortness of breath.

If you have lung disease, you may not be able to breathe as deeply or as vigorously as normal, and you may experience coughing, chest discomfort, wheezing, shortness of breath, and unusual fatigue. If you have any of these symptoms, reduce your exposure to particles and follow your doctor’s advice. Contact your doctor if symptoms persist or worsen. If you have asthma, carefully follow your asthma management plan when particle levels are high. Your doctor can help you develop a plan if you don’t have one.

If you have heart disease, particle exposure can cause serious problems in a short period of time even heart attacks with no warning signs. So don’t assume that you are safe just because you don’t have symptoms. Symptoms such as chest pain or tightness, palpitations, shortness of breath, or unusual fatigue may indicate a serious problem. If you have any of these symptoms, follow your doctor’s advice.

How can you avoid unhealthy exposure?

Your chances of being affected by particles increase the more strenuous your activity and the longer you are active outdoors. If your activity involves prolonged or heavy exertion, reduce your activity time or substitute another that involves less exertion. Go for a walk instead of a jog, for example. Plan outdoor activities for days when particle levels are lower. And don’t exercise near busy roads; particle levels generally are higher in these areas.

Particle levels can be elevated indoors, especially when outdoor particle levels are high. Certain filters and room air cleaners can help reduce indoor particle levels. You also can reduce particle levels indoors by not smoking inside, and by reducing your use of other particle sources such as candles, wood-burning stoves, and fireplaces.

How can the Air Quality Index help?

In many areas, local media provide air quality forecasts telling you when particle levels are expected to be unhealthy. Forecasts use the same format as EPA’s Air Quality Index, or AQI, a tool that state and local agencies use to issue public reports of actual levels of particles, ground-level ozone, and other common air pollutants.

AIRNow

AIRNow (http://epa.gov/airnow) is a Web site that gives daily information about air quality, including ground-level ozone and particles, and how they may affect you. AIRNow contains:

• Real-time particle levels for many locations.
• Air quality forecasts for many cities across the country.
• Kids’ Web page and associated teacher curriculum.
• Smoke Web page.
• Links to state and local air quality programs.
• Ideas about what you can do to reduce particles. For example, you can keep your car, boat, and other engines well-tuned, and avoid using engines that smoke. You can also participate in local energy conservation programs.

Using the AQI’s color-coded scale, these forecasts help you quickly learn when air pollution is expected to reach unhealthy levels in your area. In the newspaper forecast shown at right, for example, the black arrow points to the “orange” range, indicating that particle levels are expected to be unhealthy for sensitive groups. On television, you might hear a meteorologist say something like this: “Tomorrow will be a code orange air quality day, with particle pollution at levels that are unhealthy for sensitive groups. If you have heart or lung disease, or if you’re an older adult or a child, you should plan strenuous activities for a time when air quality is better.”

http://eponline.com/Articles/2011/09/05/Air-Quality-Researchers-Tackle-Health-Implications-of-Ultrafine-Particles.aspx?p=1

5 Sept. 2011

Three studies by a University of California, Davis, air-quality research group are adding to the growing body of data suggesting that very fine and ultra-fine airborne metal particles are closely linked to serious human-health problems, including heart disease.

UC Davis air-quality expert Thomas Cahill and colleagues report the findings of the three studies in the September special issue on aerosols and health of the journal Aerosol Science and Technology. The three papers were selected for publication by Paul Solomon, senior research scientist at the U.S. Environmental Protection Agency.

The research was conducted by UC Davis’ Detection and Evaluation of Long-range Transport of Aerosols Group, including researchers at Arizona State University. The work was done in collaboration with the Health Effects Task Force of the nonprofit organization Breathe California of Sacramento-Emigrant Trails.

“These studies yielded unique epidemiological data supporting a growing body of evidence from laboratory and medical studies, which strongly suggests that very fine and ultra-fine metal particles are damaging to human health,” said Cahill, a professor emeritus of physics and atmospheric sciences.

“These tiny metal particles penetrate deep into the lungs and the cardiovascular system, damaging arteries and the heart itself,” Cahill said.

He noted that risk-assessment of these particles is made more difficult by the fact that standard air samples don’t separate out the dangerous particles. Furthermore, there are almost no data available on the composition of these particles in the surrounding atmosphere.

In the three papers, Cahill and colleagues investigate the role that very fine and ultra-fine metal particles play in contributing to heart attacks, the reduction in heart attacks when ultra-fine particles were removed from the air in California’s San Joaquin Valley, and the increase in estimated cancer rates downwind of a railyard in the Northern California town of Roseville. The results from these studies are as follows:

Fine and ultra-fine metallic particles in the Central Valley

Researchers took air samples at five sites in the Central Valley, from Redding south to Bakersfield, and analyzed 42 elements, including very fine metals in eight size ranges, as well as integrated organic species. The samples were taken every three hours during a 17-day period in January 2009, when weather conditions caused the air to stagnate in the valley.

The Central Valley runs the length of inland California; it is composed of the Sacramento Valley to the north and the San Joaquin Valley to the south.

The research team found a correlation between the levels of the particles in the air and the death rates due to ischemic heart disease, with the highest rates for both occurring in the southern San Joaquin Valley near Bakersfield. Ischemic heart disease is characterized by a reduction in blood supply, often due to the clogging of the arteries.

An analysis of local meteorology in that area revealed a nighttime flow of air off of nearby Interstate 5 and Highway 58, both steep stretches of road that require heavy breaking by large trucks traveling down into the valley. The researchers suggest that the fine and ultra-fine particles likely come from the brake pads, brake drums and metal additives in lubricating oils of trucks and cars passing through the valley.

The researchers note that the findings from this study also may offer a clue as to why children who grow up near freeways are more likely to suffer loss of lung function.

Funding for the study was provided by the Sacramento Resources Legacy Fund, the Sacramento Metropolitan Air Quality Management District, the Yolo-Solano Air Quality Management District and Breathe California of Sacramento-Emigrant Trails.

Heart attack rates declined when ultra-fine particles were removed

In the second study, the researchers examined patterns in the atmospheric levels of very fine and ultra-fine aerosol particles of vanadium and nickel in the southern San Joaquin Valley. Levels of these metal aerosols, as well as ammonium nitrate and sulfate, had historically been much higher in the southern end of the San Joaquin Valley than in the northern end, due to the burning of crude oil to generate steam used to recover heavy petroleum from area oil wells.

Furthermore, the southern San Joaquin Valley also historically had death rates due to strokes and ischemic heart disease that were roughly 60 percent greater than the rest of the Central Valley.

In 1990, new technologies were developed that made it possible to use natural gas, rather than crude oil, to fuel the petroleum extraction efforts. Cahill and colleagues measured the ultra-fine vanadium and nickel aerosol particles in 2009 and compared those levels to pre-1990 levels, when crude oil was still being used for petroleum recovery.

The data revealed that there was a sharp decrease in ischemic heart disease observed in 2007 in the southern San Joaquin Valley that was mirrored by a dramatic decline in the levels of vanadium and nickel aerosols. Those data support a growing body of evidence from laboratory and epidemiological studies, which suggest that the vanadium and nickel aerosols may play a role in causing ischemic heart disease.

These findings, along with other work by UC Davis’ DELTA Group, also suggest that the rate of ischemic heart disease observed in communities downwind from the Port of Los Angeles in 2008 may be related to effluent from ocean-going ships that burn crude or residual oil.

Funding for this study was provided by the Resources Legacy Fund of Sacramento, Breathe California of Sacramento-Emigrant Trails and the Sacramento Metropolitan Air Quality Management District.

Aerosols monitored downwind from railyard

In the third study, Cahill and colleagues monitored inorganic and organic aerosols downwind from the Roseville Railyard, northeast of Sacramento, in order to develop a profile of emissions from the railyard activities.

The railyard is one of the largest such maintenance and service sites in the western United States, with more than 31,000 locomotives visiting annually.

The researchers found that most of the aerosols monitored at this site were associated with exhaust from the trains’ diesel-fueled engines. Most of the particles, especially the known carcinogen benzol[a]pyrene, were in the very fine and ultra-fine size-range, increasing the chances that they would be caught up in people’s lungs.

The researchers also identified coarse-soil aerosols that were contaminated with metals and petroleum-derived particles.

Findings from this study identified very fine transition metals and contaminated soils that are potentially important to human health, and confirmed estimates of the health impacts of diesel exhaust downwind of the railyard that were made earlier by the California Air Resources Board.