LEARNSMART - Air Pollution

What are the greenhouse gases that the EPA regulates?

Sulfur hexafluoride, methane, perfluorocarbons, carbon dioxide, and hydrofluorocarbons.

__ are second only to particulate matter from smoke in terms of damage caused to human health by air pollutants.

Sulfur ions

Acid rain has polluted 18,000 lakes in __. These lakes cannot support game fish or other sensitive aquatic species.

Sweden

What are the steps leading to the bioaccumulation of anthropogenic mercury at hihger levels of the food chain?

1. Coal burning releases mercury. 2. Bacteria in aquatic environments convert mercury to methyl mercury. 3. Small fish eat many mercury-laden bacteria. 4. Large fish and other predators eat many mercury-laden smaller animals.

What are some of the sources of air pollutants for the 3-km-thick toxic cloud of ash, acids, aerosols, dust, and photochemical reactants that regularly covers the entire Indian subcontinent?

Abundant forest fires, burning of agricultural waste, and increased use of fossil fuels.

What were issues addressed in the amendments added to the Clean Air Act in 1990?

Acid rain, toxic air emissions, and controls for ozone-depleting chemicals.

__ is any undesirable change in the physical characteristics or chemistry of the atmosphere, like noise, odors, and light pollution.

Aesthetic degradation

What are hazards associated with or directly caused by particulate matter?

Airborne dust is a primary source of allergies worldwide, pathogens can travel in dust storms between continents, and higher particulate levels are linked with higher rates of heart and lung disease.

What are substances that are captured by physical devices after combustion in order to reduce air pollution?

Ash, hydrocarbons, and sulfur

What are the two most important secondary pollutants in terms of health and ecosystem damage?

Atmospheric acids and photochemical oxidants.

__ binds to hemoglobin and decreases the ability of red blood cells to carry oxygen.

Carbon monoxide

__ is a colorless, odorless, highly toxic gas produced by the incomplete combustion of fuel.

Carbon monoxide

What are "criteria pollutants" for the EPA, pollutants that contribute significantly to air quality degradation?

Carbon monoxide and ozone, total suspended particulate matter, lead, sulfur dioxide and nitrogen oxides.

City dwellers in __ are up to 6 times as likely to die of lung cancer when compared to people who live outside of this country's urban areas.

China

The country of __ is rapidly growing, as many of its 400,000 factories have no pollution control and home coal burners and factories emit 10 million tons of soot and 15 million tons of sulfur dioxide annually.

China

First signed into law in 1963, the __ was the first national law for air pollution in the US. It has seen many amendments added to it since it was first passed.

Clean Air Act

Once one of the world's most polluted cities, __ saw improvements in air quality after requiring catalytic converters for automobiles and introducing unleaded and low-sulfur diesel fuels.

Delhi, India

What are examples of particulate removal techniques?

Employing electrostatic precipitators and filtering air using a mesh of material like cotton cloth.

How does acid rain deposition occur?

Fallout of dry particles, fog, snow, and dew.

True or false: Nitrous oxide is hazardous for many reasons, but it isn't a greenhouse gas.

False, it is a GHG.

True or false: Because ozone is valuable in the stratosphere as a shield from UV radiation, its occurrence at ground level is also positive.

False, ozone is a strong oxidizer and is hard on sensitive plant and animal tissues.

When does temperature inversion occur?

It occurs when a stable layer of warmer air lies above cooler air, often when cold air settles in a valley surrounded by hills or mountains.

What are the negative consequences of aesthetic degradation?

Light pollution can confuse wildlife like birds and it can cause stress in humans that affect our health.

What are the factors that elevate the health risks associated with air pollution?

Having a preexisting respiratory or cardiovascular condition, having a supersensitivity due to genetics, living in a polluted city, or being very young or old.

__ are specially regulated in the Clean Air Act because of their adverse impact on human health; they include carcinogens, neurotoxins, mutagens, teratogens, and endocrine disru

Hazardous air pollutants

Why is clean air legislation controversial?

Industry and energy groups insist that controls are too expensive, while health advocates argue that industries should pay for pollution prevention.

What is particulate matter?

It includes solid particles or liquid droplets suspended in a gaseous medium. Examples include smoke, pollen, ash, and dust.

What is electrostatic precipitation?

It involves particulate removal by trapping material on charged plates as effluent (smoke) makes its way to the smokestack.

What is ground-level ozone?

It is a three-atom molecule of oxygen and is formed when volatile organic compounds react with other pollutants in the presence of sunlight.

What is aesthetic degradation?

It is any undesirable change in the physical characteristics or chemistry of the atmosphere.

What is cap-and-trade?

It is the market-based system that allows companies to buy and sell pollution credits.

What does NAAQS stand for?

National ambient air quality standards, based on health and environmental criteria.

Which two pollutants have not dropped significantly even with the Clean Air Act?

Nitrogen oxides and particulate matter.

What is the largest cause of obstructive lung disease and preventable death in the world?

Smoking

What are the two sources of indoor air pollution that cause the most health problems?

Smoking and cooking and heating fires.

What is the most common level of air quality found in areas where people live?

The air is contaminated to some degree.

Differentiate between fugitive emissions and point-source emissions.

The former do not vent from a single location, while the latter can be tracked to a single location like a smokestack or other venting system.

Differentiate between primary and secondary pollutants.

The former is released directly from the source into the air in a harmful form, while the latter is converted to a hazardous form after it enters into the air following exposure to other chemicals and sunlight.

What is the difference between ambient and atmospheric ozone?

The former is the ozone around us at ground level, while the latter is the ozone that is present above us in the stratosphere.

What is the goal of the Montreal Protocol and how has it been achieved?

The goal is to restore stratospheric ozone through the reduction of CFCs and HCFCs.

What are some problems with the cap-and-trade system?

They are inappropriate for a substance that is toxic at very low levels, as caps are large enough to measure and trade in the system may be too large for substances that are toxic at low levels. Additionally, this solution may allow a pollutant to be emitted long after it could have otherwise been eliminated.

What are volatile organic compounds?

They are organic chemicals that evaporate easily or exist as gases in the air.

What are aerosols?

They are very fine solid or liquid particles suspended in the atmosphere.

How can air pollutants be directly toxic to plants?

They damage cell membranes in the same way irritants can damage human lungs, but it is often difficult to tell if the damage is from pollution or disease.

When do nitrogen oxides form?

They form during combustion or burning, when the nitrogen in fuel or in the air is heated in the presence of oxygen.

True or false: Most of the atmospheric sulfur comes from anthropogenic sources.

True, about 2/3 of the atmospheric sulfur comes from activities associated with industry, processing, and fossil fuels.

True or false: Indoor air pollution is often higher than it is outdoors.

True, outdoor pollution control methods and a lack of focus on indoor pollutants have led to indoor air quality often being much worse.

What are natural sources of sulfur in the Earth's atmosphere?

Volcanoes and hot springs, sea spray evaporation, and biogenic emissions.

Atmospheric levels of CO2 are increasing by...

about 0.5% per year.

Eggs and young fish are killed when lakes receive __ and subsequently, the water's __ level drops to about 5.0.

acid rain, PH

On Mt. Mitchell in North Carolina, almost all red spruce and Fraser fir above 2,000 meters in elevation are in severe decline due to the stress of...

air pollution, insects, fog, and acid rain.

As referenced in US pollution regulations, the air around us is called...

ambient air.

Since the use of lead was banned in the US, children's average __ levels of lead have dropped by 90%.

blood

Air pollution can cause people to become ill with __, a disease caused by inflammation of the bronchioles. Severe forms of this disease can lead to __, an irreversible chronic obstructive disease.

bronchitis, emphysema

The oxidation of organic compounds by organisms (plants, animals, bacteria) during respiration fuels their activities and releases __ into the air. This compound is then taken in by photosynthetic organisms as they store the energy absorbed from the sun.

carbon dioxide

Antarctic sunlight that returns in the springtime provides the energy to free chlorine in CFCs, or __. The chlorine, in turn, destroys ozone.

chlorofluorocarbons.

Changing from the use of __ to another fuel, like natural gas or nuclear power, can eliminate all sulfur emissions as well as reduce emissions of particulates and heavy metals.

coal

Because most air pollution in the developed world is associated with transportation and energy production, the most effective air pollution strategy would be __, examples of which include...

conservation measures; reducing electricity consumption, insulating homes and offices, and developing better public transportation

Major problems associated with nitrogen oxides include...

contribution to atmospheric acidification and acid rain, and production of photochemical smog.

Air pollution can damage buildings and infrastructures by...

creating a buildup of smoke and soot, oxidizing paint, causing flaking, and corroding steel.

The 6 major air pollutants (sulfur dioxide, nitrogen oxides, carbon monoxide, ozone, lead, and particulate matter) are known as...

criteria pollutants.

Since the Clean Air Act began regulating mercury emissions in the US, they have...

decreased, as many states have instituted rules aimed at capturing mercury before it leaves the smokestack.

Air pollutants are commonly inhaled, but __ through the skin is also an important pathway of pollution exposure affecting human health.

direct exposure

The Clean Air Act does add management costs since removing pollutants costs more than not doing so. The economic benefits of reducing air pollution have been shown to be...

much greater than the costs.

One way in which __ is formed naturally occurs when bacteria consume nitrogenous materials in soil or water.

nitrogen oxide

The biological component of the annual carbon cycle is balanced, since respiration-fueled release of carbon by organisms equals the uptake of carbon by...

photosynthetic organisms.

Natural air pollutants include...

sea spray from the ocean, ash, toxic gases, and carbon dioxide from volcanoes.

The thick plume of polluted air that forms over __ and moves out over the Indian Ocean, lower sea surface temperatures as it blocks some sunlight. It can move halfway around the globe in a __.

southern Asia; week

Because coal varies in its __ content, switching from types that contain a high level of this substance to a low level will reduce its emissions on the air.

sulfur

Crushing, washing, and gasifying coal can reduce the amount of __ released into the air when coal is used a fuel source. However, these methods also cause an increase in solid waste and water pollution problems.

sulfur and metals

Regarding the regulation of GHGs, in 2007 the US Supreme Court ruled it was...

the EPA's responsibility to limit these gases on the grounds of public health and welfare within the meaning of the Clean Air Act.

Wind can carry air pollutants up to __ of miles away from the original source of the pollution.

thousands

The "new source review" established in the Clean Air Act amendment of 1977 allowed polluters to exempt older equipment from the new pollution limits...

until the equipment was upgraded and replaced. Decades after the "new source review" some of the grandfathered-in equipment is still running and some companies have expanded the capacity of older facilities rather than build new ones.