Chapter 4: Air Pollution and Atmospheric Disposition

Asthma

A condition in which a person's airways become inflamed, narrow and swell, and produce extra mucus, which makes it difficult to breathe.

Principle or Criteria Pollutants

A group of six pollutants that the EPA uses to define air quality; they are CO, NO2, SO2, PM, O3 and Pb.

National Ambient Air Quality Services

A set of air quality standards set by the EPA (as required by the Clean Air Act), for widespread pollutants considered harmful to the public and environment.

Non-Attainment

An area of a state that does not meet the National Air Quality Standard for a criteria pollutant for a period of time. For areas that are designated non attainment, states must submit a plan (called a state implement plan) which outlines the specific strategies it will use to get areas back into attainment. There are also specific deadlines that states must meet to submit their plans and achieve compliance.

Volatile Organic Compound (VOCs)

Any organic compound which is unstable and evaporates readily to the atmosphere; involved in atmospheric ozone production.

Carbon Monoxide

CO is formed when carbon in fuel is completely burned. It is the primary component of vehicle emissions that, according to the EPA, contributes about 56% of all CO emissions nationwide. At high levels, CO is poisonous and even lethal to healthy people.

Lead

Due to the phase out of leaded gasoline, metals manufacturing is now the major source of lead emissions and highest concentrations of lead are generally found near lead smelters.

Sulfur Dioxide

Easily dissolved in water; these gases are formed when fuel containing sulfur (e.g., coal) is burned, SO2 dissolves in water vapor to form acid and other products that can be harmful to people and their environment. Power plants, especially those that burn coal, are by far the largest single contributor of SO2 pollution in the United States, accounting for more than 2/3 of all SO2 emissions nationwide.

Clean Air Act

First enacted in 1970, it authorized the establishment of federal and state regulations that limit stationary (point) and mobile (non point) sources of air pollutants.

Secondary Standards

Have limits in pollutants in order to protect public welfare, things like protection against decreased visibility, damage to crops, and vegetation.

Flue Gas desulferization system

Is a set of technologies used to remove sulfur dioxide (SO. 2) from exhaust flue gases of fossil-fuel power plants, and from the emissions of other sulfur oxide emitting processes.

Describe the national trends in criteria levels for air pollutants-especially NO2 and SO2.

Most pollutants show a steady decline throughout that time period (1990-2012), meaning the air quality has improved since the Clean Air Act was amended more than two decades ago. Despite improving air quality overall in the United States, ground-level ozone remains the most problematic in terms on the NAAQS in most areas. The decrease in average NO2 and SO2 concentrations over the 20 years can be attributed to a combination of factors including enforcement actions, tougher state laws, and reductions anticipated from EPA's Clean Air Interstate Rule, a rule designed to cap SO2 and NOx emissions in states east of the Mississippi River.

Explain how ground level ozone forms.

NO2 is broken apart by sunlight resulting in atomic oxygen. The atomic oxygen then combines with diatomic oxygen resulting in a molecule of ozone.

Nitrogen Oxide

NOx is a general term for a group of highly reactive gases that contain nitrogen and oxygen in varying amounts. Although a primary pollutant, NOx is also one of the main ingredients involved in the formation of ground-level ozone and acid rain.

Differ between primary and secondary pollutants and point and non-point sources.

Primary pollutants: are compounds emitted directly into the air, such as SO2, NO2, suspended particulate matter, and CO. They are emitted from point sources, such as industrial stacks and coal-burning power plants and non-point sources, such as motor vehicles. Secondary pollutants: are formed in the atmosphere through chemical reactions of the primary pollutants, usually involving sunlight.

Air Quality Index

Provides the public with clear and timely information on local air quality, the health concerns for different levels of air pollution, and now you can protect your health when air pollutants reach unhealthy levels.

Scrubbing

Removing impurities released during the combustion of certain types of fossil fuels.

How does the Clean Air Act help to regulate air pollutants?

Requires the EPA to set National Ambient Air Quality Standards for pollutants considered harmful to the public's health and environment.

Primary Standards

Set limits on pollutants in order to protect public health, esp. health of sensitive populations such as children, elderly, and those who suffer from asthma.

What are the NAAQS? What pollutants does it regulate?

The National Ambient Air Quality Standards; two types: primary standards and secondary standards. Primary standards set limits on pollutants in order to protect public health; secondary standards have limits that protect public welfare, things like protection against decreased visibility, damage to crops, and vegetation.

How are coal companies attempting to lower emisssions of Sulfur dioxide and nitrogen oxides

Trying to use scrubbers that will reduce SO2

Wet Scrubbers

Using liquid to trap particles and gases in the exhaust stream, can reduce SO2 by 90-95%

Ozone Precursers

Vehicle, industrial emissions, gasoline vapors, and chemical solvents are the major anthropagenic sources of these chemicals.

Particulate Matter

particle pollution is actually made up of a number of components including ash, soil, and dust particles. Their impact, in terms of health, is directly linked to their size with the greatest concern focused on particles that are 10 micrometers in diameter or smaller. Have the ability to enter lungs and bloodstream and cause serious health effects.