Chapter 10- Air Quality

Differentiate between point and non-point sources of pollution

Point source: stationary, localized sources such as a smokestack of a factory. Each point source has the potential to produce large amounts of pollutants. Non-point source: produces relatively small amounts of chemicals or aerosols that only have an effect in cumulative sense. (automobiles, residential fireplace, agriculture)

Differentiate between primary and secondary pollutants

Primary air pollutants: chemicals or particles that are directly emitted from identifiable sources (carbon monoxide and sulfur dioxide released when fossil fuels burn, volcanic eruptions releases element mercury). Secondary Pollutants: chemicals or particles that are produced in the atmosphere as a result of reactions among chemicals or aerosols. (The ozone that accumulates in city air during the daytime produced by reactions involving NO and 02 in the presence of sunlight.

What are the primary sources of Sulphur dioxide and nitrogen oxide?

The primary sources of Sulphur dioxide and nitrogen oxide is Industrial Smog.

What is the difference between trace gases, VOCs, particulate matter, and aerosols?

Trace Gases: Gases that makes up less than 1% of Earths atmosphere are called trace gases. The atmosphere contains hundreds of trace gases, most of which are present in concentration expressed in parts per million or parts per billion. It is these variable gases that have the potential to become pollutants. Volatile organic compounds (VOCs): organic chemicals that can vaporize into the air. VOCs are a diverse arrange of chemicals with a wide variety of chemicals. Some are produced naturally. Some are methane, solvents, paints, gasoline, exhaust from automobiles. Particulate Matter (PM): very small solid-liquid particles suspended in the air Aerosols: Suspended particles, they originate from both natural and human sources. (tiny water droplets that makeup fog and clouds, virus, smoke, bacteria, algae, pollen). These are health hazards if taken up by humans or animals. The size is significant because it determines how long these will remain within the atmosphere.

What are some of the sources of air pollution?

volcanic eruptions(emitting sulfur compounds), dust, smoke, sea salt, pollen, rocks (that are too rich in uranium

What are the three kinds of pollution in the troposphere?

(1)Acid Deposition: the dispersion of acid-containing gases, aerosols, and rain onto soils, plants, buildings, and bodies of water. It forms from sulfur and nitrogen oxides that are emitted by the burning of fossil fuels. (2)Heavy metal: pollution comes primarily from anthropogenic sources, including the combustion of coal, metal sweltering, and wast incineration. Mercury and lead are particularly important in heavy metal pollutants. (3)Smog: complex mixture of both primary and secondary pollutants

What factors influence the dispersion and deposition of air pollution?

-Airflow patterns: Pollutants are dispersed by diffusion, convention, and wind patterns. These process very at local, regional, and global scales. *Temperature inversion: weather patterns cause a layer of warm air to form above colder air. -The height of emission: The hight at which point sources emit pollutants into the atmosphere has a large effect upon the concentration of those pollutants near the ground. The greater the emissions hight, the greater the distance pollutants will be carried and the more mixing of dilution will occur. -Atmosphere lifetime: The lifetime of the gas molecule or a particle is the average time that it remains in the atmosphere. This depends on the chemical stability of the pollutants. *Dry deposition: nonliquid particles are removed from the atmosphere by gravity. Because larger particles are less easily suspended in the air, they tend to have a higher deposition rate and shorter lifetime than smaller particles. *Wet Deposition: trace gases and particles are captured in raindrops, snowflakes, or droplets of fog.

Describe the effects aerosols in the stratosphere. Which chemicals can destroy the ozone in the stratosphere?

-Chemicals that contain elements chlorine and bromine can destroy the ozone in the stratosphere. These chemicals include (CFCs ultraviolet light cause them to realize chlorine, which catalyzed the destruction of the stratosphere) -The depletion of the ozone can create an ozone hole. This create skin cancers among many people in countries. The ozone hole is currently stabilized.

Why do the factors that made it easy to sign the Montreal protocol differ when it comes to climate change?

-Countries agreed to a timetable for phasing out the production and use of CFCs and other ozone-destroying chemicals. There was a widespread agreement about the scientific evidence for the relationships between CFCs and ozone depletion. Ozone depletion will threaten everyone. This was easy to monitor production because there was a relative number of CFC producing companies. There was also a number of substitute chemicals that they could use instead. This agreement served as a model for future agreements. -This is different compared to climate change because there is less certainty regarding causes and consequences of greenhouse gas emissions, the risk of global warming changes are not equally distributed among nations, and there is social and economic resistance to alternatives to fossil fuels.

How does acid deposition occur? What are the effects of acid deposition?

-Sulfur and nitrogen oxides dissolve in water to produce sulfuric and nitric acids. The primary sources of this are coal fired power plants. -Deterioration of buildings and statues, diminishes cropland, effects forests and freshwater ecosystems(getting ride of nutrients in soils and vegetation), damage to trees, solubility of calcium carbonate,

What does the air quality index tell us?

Air quality index: The AQI for each pollutant is scaled from 0 to 500, with 100 to its regulatory standard. Air quality is then scaled by color code. For example, air quality at AQI less than 50 is considered to be goof or green, Wheres AQI levels above 100 are considered to be unhealthy or code orange for sensitive groups such as children or the elderly.

What does air quality and air pollution mean?

Air quality: the amounts of gases and small particles in the atmosphere that influence ecosystems or human well-being. Air pollution: gases or particles that are present in high enough concentrations to harm humans, other organisms, or structures such as buildings or pieces of art.

Differentiate between industrial and photochemical smog.

Industrial Smog: composed primarily of pollutants released in coal burning. These include carbon monoxide(C0), Sulfur dioxide(S02), and particles of carbon soot. Photochemical smog: Formed when certain primary pollutants interact with sunlight. Many of these primary pollutants come from the exhaust of vehicles. Nitrogen oxide and VOCS are among the most important of these primary pollutants. These chemicals react with oxygen and water vapor to form a varies of secondary pollutants including ozone and nitrogen dioxide.