APES U7 Study Guide (Atmospheric Pollution)

What is particulate matter?

- Particulate matter is an umbrella term that covers solid particles that are small and light enough to remain suspended in the atmosphere; the majority of particulate matter comes from natural sources (i.e. volcanoes), but some comes from human sources like motor vehicles - Particulate matter is irritating to the nose/throat, can cause lung damage, can aggravate asthma, and can cause respiratory disease - Toxic particulate matter (such as lead & cadmium), which usually originates from human sources, has been tied to mutations, reproductive issues, and cancer :(

Explain what photochemical smog is, and describe its formation.

- Photochemical smog is produced when nitrogen oxides & VOCs react with heat & sunlight to produce an amalgamation of secondary pollutants—it's often formed in urban areas due to the congestion of motor vehicles in these areas - Nitrogen oxides are usually produced early on in the day, and are turned into photochemical smog by VOCs emitted from trees, congestion on the roads on sunny days, VOCs like formaldehyde and gasoline that sublimate at room temperature, and ozone concentrations (that peak in the afternoon & summer months). - Photochemical smog causes respiratory problems and eye irritation amongst citygoers, and its formation can be prevented by the subsidization of mass transit systems, which reduce congestion on the roads (& by effect, the production of nitrogen oxides and harmful VOCs).

What is the difference between primary & secondary air pollutants?

- Primary air pollutants are harmful substances that are emitted directly into the atmosphere (i.e. sulfur dioxide & carbon monoxide) - Secondary air pollutants are formed when primary pollutants interact with one another OR with other atmospheric elements (i.e. photochemical smog & sulfuric acid)

What is Radon-222?

- Radon-222 is a naturally occurring colorless, odorless, and radioactive gas that can be found as rock/soil deposits (can seep into homes situated upon such deposits) - Has been connected to lung cancer with long-term exposure, especially amongst moderate to heavy smokers

What is SO2?

- Sulfur dioxide (SO2) is a colorless gas with an irritating odor (smells like rotten eggs!) - 1/3 comes natural sources (Sulfur Cycle), and 2/3 comes from human sources (combustion of coal for electricity generation & the refining of crude oil)

What is H2SO4?

- Sulfuric acid (H2SO4) is formed when atmospheric sulfur dioxide (SO2) combines with water

Summarize the Clean Air Act.

- The Clean Air Act (1970, 1977, and 1990) has been put into effect and monitored by the EPA (Environmental Protection Agency) in order to reduce levels of air pollution present in the atmosphere; essentially, it sets regulations for key pollutants through NAAQS (National Ambient Air Quality Standards)

Where do the compounds that contribute to acid deposition come from?

- The atmospheric NOx and SOx that combine to create what's commonly known as "acid rain" are found from both anthropogenic (human-made) and natural sources - Specifically, NOx is primarily emitted from motor vehicles and coal-burning power plants, and SOx is primarily emitted from coal-burning power plants

Explain what a thermal inversion is, and describe the conditions under which it is most likely to occur.

- Thermal inversions are locations wherein the natural temperature gradient in the atmosphere is altered, and air temps. at the surface are cooler than temps. higher up in the atmosphere (layer of warm air "sandwiched" between two layers of cool air) - As a result of this phenomenon, cool air—which is denser than warm air and thus cannot rise/mix with warmer air—remains at the surface and traps surface-level pollutants like smog/particulates at the ground level - Thermal inversions are most likely to occur in areas surrounded by mountains (i.e. Mexico City & Los Angeles) - confirm with Mrs. O!

What are VOCs?

- VOCs are organic compounds that exist in the atmosphere as gases - Typically hydrocarbons (such as isoprene [C3H8] or terpenes [C10H15]) that are released by the leaves, or methane (CH4) released from animals in the form of waste - Other VOCs are used in industrial solvents, dry-cleaning fluids, and components of plastics, drugs, and gasoline (for ex., benzene is found in motor vehicle emissions & tobacco smoke) - Long-term exposure to VOCs can cause leukemia, blood disorders, and damage to one's immune system

Define acid deposition, and explain the risks associated with acid deposition on human health, ecosystems, and human-made structures.

- Acid deposition (more commonly known as "acid rain") comes from the combination of NOx and SOx with water vapor in the atmosphere; the NOx involved usually comes from motor vehicles AND coal-burning power plants, and the SOx involved usually comes from coal-burning power plants... - The effects of acid deposition are commonly seen in communities that are downwind from coal power plants due to the wide-ranging effects of emissions, and acid deposition can lead to the acidification of soils (that can lead to the leaching out of toxic heavy metals like lead, and changes in the natural pH that cause changes in vegetation grown) - Regional differences in soil and bedrock affect the impact that acid deposition has upon certain regions (calcium carbonate [CACO3] can neutralize effects of acid rain)

What is CO2?

- Carbon dioxide (CO2) is a colorless, odorless gas that is heavily prevalent in the Earth's troposphere - Naturally occurring, but a large amount comes from human sources—surprisingly, left unregulated by the Clean Air Act...

What is CO?

- Carbon monoxide (CO) is a colorless, odorless, and toxic gas that's formed during the incomplete combustion of carbon-containing materials - Reduces the ability of individuals' blood to transport oxygen to vital organs/tissues (via interaction with hemoglobin in RBCs) - Comes from motor vehicle exhaust, fires, and tobacco smoke

List examples of indoor air pollutants, the potential health effects of each, and strategies for dealing with each. Briefly describe how air pollution affects human health, plants, aquatic life, and materials.

- Forms of natural indoor pollution include Radon-222, dust, asbestos, mold, and pollen - Forms of human-made indoor pollution include VOCs coming from furniture, paneling, and carpets, FORMALDEHYDE from building materials, furniture, upholstery, and carpeting, and LEAD from paints - CO, NOx, SO2, particulates, and tobacco smoke are all things that are emitted via combustion from furnaces & cigarettes @ home

What is HNO3/NO3-?

- Nitric acid (HNO3) and nitrate salts (NO3-) form when NO2 (nitrogen dioxide) & water vapor react in the atmosphere, contributing to acid rain—which damages trees, soils, and aquatic ecosystems!

What is NO?

- Nitrogen oxide (NO) is a colorless gas formed when nitrogen reacts with oxygen in the atmosphere under high-combustion temps. found in automobile engines and coal power plants - Produced naturally (in small amounts) by lightning & bacteria during the Nitrogen Cycle

What is N2O?

- Nitrous oxide (N2O) is a common greenhouse gas emitted from fertilizers and from the burning of fossil fuels!

What is O3?

- O3, or ozone, is a colorless and highly reactive gas that mainly exists in the stratosphere, absorbing harmful UV radiation to protect humans - While stratospheric ozone is quite helpful, ozone in the troposphere, or ground-level ozone, is actually a primary component of photochemical smog, and serves to reduce individuals' resistance to colds, cause coughing/breathing problems, and aggravate individuals' asthma.

Provide some strategies that could prevent acid deposition, and provide some strategies that could be used to remediate the effects of acid deposition.

ASK MRS. OSTROSKY!