Particulates and Air Pollution

Presented By:Beenish Naheed 14-MS-01Muhammad Shoaib 14-MS-04

Particulate is:A mixture of particles found in the air, including dust, dirt, soot, smoke, and liquid droplets. Some particles are large or dark enough to be seen as soot or smoke. Others are so small that individually they can only be detected with an electron microscope.

Particles with diameters between 2.5 and 10 micrometers are referred to as CoarseParticles with diameter 2.5 micrometers and smaller are referred to as Fine

Sources of PM Mobile Sources(vehicles)VOCs, NO2Stationary Sources (power plants, factories)NO2, SO2Area Sources(drycleaners, gas stations)VOCsNatural Sources (forest fires, volcanoes)

Sources of fine particlesAll types of combustion -Motor vehicle -Power plants -Wood burning, etc.-Some industrial processes

Sources of coarse particles include crushing or grinding operations and dust from paved or unpaved roads

Ambient Fine Particles Can stay in the atmosphere from days to weeks, and travel hundreds of miles. Particles can be transported long distances and impact large of numbers of people

Chemical Composition of PM2.5 SulfatesNitratesElemental carbonOrganic carbonTrace elements such as metalsVarying amounts of water.

Sulfates

Sulfur dioxide (SO2), mainly from combustion of fossil fuel,is oxidized in the atmosphere to form sulfuric acid (H2SO4) particles. Ammonium sulfate (NH4)2SO4 is the most common sulfate species in ambient aerosol samples.

Nitrogen oxides (NOx= NO + NO2) are formed during combustion or any high temperature process involving air

Eventually can be converted in the atmosphere into both nitric acid (HNO3) particles and the particulate ammonium nitrate (NH4NO3).

Elemental Carbon. Chain agglomerates of very small elemental carbon (EC) particles are formed during combustion, such as in open hearth fireplaces, wood stoves and diesel engines.

Organic Carbon. Several categories of organic carbon (OC) compounds are also often found in ambient air, as follows:Primary-anthropogenic (man-made). Incomplete combustion also leads to hundreds of organic compounds being present in the atmosphere as particles, including polycyclic (Polynuclear) aromatic hydrocarbons (PAHs).

Secondary-anthropogenic. Some complex organic compounds react with ozone or other atmospheric constituents to form particles.

Primary biogenic. Viruses, some bacteria, and plant and/or animal cell fragments may compose a portion of the fine particulates in the atmosphere.Secondary biogenic. Terpenes, which are cyclic olefins released by plants, also react in the atmosphere to yield organic particulate matter.

Trace Elements

A variety of metals and non-metals are volatilized during the combustion of fossil fuels, smelting of ores, and incineration of wastes and are emitted as fine particles (or vapors which rapidly form fine particles).

What Adverse Health Effects Have Been Linked to PM?Premature deathLung cancerExacerbation of COPDDevelopment of chronic lung diseaseHeart attacksHospital admissions and ER visits for heart and lung disease

What Adverse Health Effects Have Been Linked to PM?Respiratory symptoms and medication use in people with chronic lung disease and asthmaPre-term birthLow birth weightChronic bronchitisWork and school absences

Who is Most at Risk from Exposure to Fine Particles?The Elderly: Studies estimate that tens of thousands of elderly people die prematurely each year from exposure to ambient levels of fine particles. Studies also indicate that exposure to fine particles is associated with thousands of hospital admissions each year. Many of these hospital admissions are elderly people suffering from lung or heart disease.

Individuals with Preexisting Heart or Lung Disease: Breathing fine particles can also adversely affect individuals with heart disease, emphysema, and chronic bronchitis by causing additional medical treatment. Inhaling fine particulate matter has been attributed to increased hospital admissions, emergency room visits and premature death among sensitive populations.Who is Most at Risk from Exposure to Fine Particles?

Children: The average adult breathes 13,000 liters of air per day; children breathe 50 percent more air per pound of body weight than adults. Because children's respiratory systems are still developing, they are more susceptible to environmental threats than healthy adults. Exposure to fine particles is associated with increased frequency of childhood illnesses, which are of concern both in the short run, and for the future development of healthy lungs in the affected children.

Who is Most at Risk from Exposure to Fine Particles?

Asthmatics and Asthmatic Children: More and more people are being diagnosed with asthma every year. Fourteen Americans die every day from asthma, a rate three times greater than just 20 years ago. Children make up 25 percent of the population, but comprise 40 percent of all asthma cases. Breathing fine particles, alone or in combination with other pollutants, can aggravate asthma, causing greater use of medication and resulting in more medical treatment and hospital visits.

Who is Most at Risk from Exposure to Fine Particles?

The Role of InversionsA temperature inversion is a thin layer of the atmosphere where the normal decrease in temperature with height switches to the temperature increasing with height. This can cause several weather-related effects. One is the trapping of pollutants below the inversion, allowing them to build up. If the sky is very hazy, or is sunsets are very red, there is likely an inversion somewhere in the lower atmosphere.

Major Episodes of Severe Air Pollution due to Inversions 1930: Meuse River Valley, BelgiumAn inversion led to a high concentration of pollutants during a period of cold, damp weather60 deaths recorded

Major Episodes of Severe Air Pollution due to Inversions 1948: Donora, PennsylvaniaSimilar inversion to Meuse River Valley 20 deaths observed1952: London Killer fog (right)Primary source: domestic coal burning 4,500 excess deaths recorded during week- long period in December

How Does PM Cause Health Effects?Several theories have been advanced as to the mechanism of action. It is likely that more than one mechanism is involved in causing PM-related health effects. Theories include the following:PM leads to lung irritation which leads to increase permeability in lung tissue;PM increases susceptibility to viral and bacterial pathogens leading to pneumonia in vulnerable persons who are unable to clear these infections;

How Does PM Cause Health Effects? 3. PM aggravates the severity of chronic lung diseases causing rapid loss of airway function;

PM causes inflammation of lung tissue, resulting in the release of chemicals that impact heart function;PM causes changes in blood chemistry that results in clots that can cause heart attacks.

What Improvements Would Result from EPA's New Standards?EPA's new standards will provide increased health protection from the following effects: About 15,000 lives each year will be saved, especially among the elderly and those with existing heart and lung diseases. Reduced risk of hospital admissions by thousands each year, and fewer emergency room visits, especially in the elderly and those with existing heart and lung diseases. Reduced risk of symptoms associated with chronic bronchitis, tens of thousands fewer cases each year.

What Improvements Would Result from EPA's New Standards?Reduced risk of respiratory symptoms in children, hundreds of thousands fewer incidences each year of symptoms such as aggravated coughing and difficult or painful breathing. Reduced risk of aggravation of asthma, hundreds of thousands fewer incidences each year, in children and adults with asthma. Reduced risks of susceptibility to childhood illnesses.

What Improvements Would Result from EPA's New Standards?Improved visibility over broad regions in the east and urban areas: The Clean Air Act placed special emphasis on preserving visibility in certain national parks and wilderness areas. In response, EPA is developing a "regional haze" program intended to ensure all parts of the country make continued progress toward the national visibility goal of "no manmade impairment."

Air Pollution Research: Setting the Future AgendaThe Committee on Research Priorities for Airborne Particulate Matter was established by the National Research Council in January 1998 in response to a request from Congress and the EPA. The Committee produced 4 reports over the period 1998 2004.

I. Immediate Priorities and a Long-Range Research PortfolioII. Evaluating Research Progress and Updating the PortfolioIII. Early Research Progress IV. Continuing Research Progress