Air Pollution

• Measurement Units

  • The most common form of expressing air pollutants is parts per million.

• Primary pollutants

  • Emitted directly into the air.

• Secondary pollutants

  • Result from the reaction of primary pollutants in the atmosphere forming a new pollutant.

• Point Source Pollution

  • Occurs when the contaminant comes from an obvious source.

• Non-Point Source Pollution

  • Occurs when the contaminant comes from a source that is not easily identifiable or from a number of sources spread over a large, widespread area.

Major Air Pollutants

• Criteria Air Pollutants

  • Set of eight air pollutants that cause smog, acid rain, and other health hazards.

  • Carbon Monoxide

    • Colorless, odorless, and tasteless gas that is slightly less dense than air. Produced from the partial oxidation of carbon-containing compounds and forms when there is not enough oxygen to produce carbon dioxide.

    • Carbon monoxide is a temporary atmospheric pollutant in some urban areas, primarily produced from the exhaust of internal-combustion engines but also from incomplete combustion of various other fuels.

  • Lead

    • Used in building construction, lead-acid batteries for vehicles, bullets and shot, fishing weights, solder, and shields for radiation.

    • Exposure to lead which generally occurs from lead-based paint chips from older buildings, mining, smelters, and municipal waste incineration, can occur from inhalation of polluted air and dust and the ingestion of lead in food and/or water.

  • Nitrogen oxides

    • Nitrogen oxide gases are formed whenever nitrogen occurs in the presence of high temperature combustion. These gases react to form acid rain.

    • When nitrogen oxides and volatile organic compounds react in the presence of sunlight, they form photochemical smog, a significant form of air pollution.

  • Ozone

    • Tropospheric ozone is a secondary air pollutant.

    • Human activities that can lead to the formation of tropospheric ozone include burning fossil fuels, and releasing VOCs.

  • Peroxyacyl Nitrates

    • Secondary pollutants.

    • They break apart in the atmosphere slowly into radicals.

    • Can cause respiratory problems, impair immune systems, cause eye irritation, and reduce crop yields.

  • Sulfur Oxides

    • The most common sulfur oxide is sulfur dioxide

    • Colorless gas with a penetrating, choking odor, and it readily dissolved in water to form an acidic solution.

    • Sulfur dioxide is toxic to a variety of plants and reduces crop yields.

  • Suspended Particulate Matter

    • Microscopic solid or liquid matter suspended in the Earth’s atmosphere.

    • In general, the smaller and lighter a particle is, the longer it will stay in the air.

  • Volatile Organic Compounds

    • Organic chemicals that have a high vapor pressure.

    • Their high vapor pressure results from a low boiling point.

  • Indoor Air Pollutants

    • Sick Building Syndrome is a term used to describe a combination of ailments associated with an individual’s place of work or residence.

• Asbestos

  • Major part of manufacturing in America started in the early 1800s and was commonly used until the mid-1970s.

  • First popular use was the lining in steam engines.

• Carbon Monoxide

  • In closed environments, concentration of carbon monoxide can easily rise to lethal levels

  • Around 50% of people, almost all in developing countries, rely on coal and biomass in the form of wood, dung, and crop residues for domestic energy.

  • These materials are burned in simple stoves with very incomplete combustion.

  • Women and young children are exposed to high levels of indoor air pollution every day.

• Formaldehyde

  • Organic chemical that is prevalent in the indoor environment. It is a carcinogen that is linked to nasal and lung cancer.

  • Persistent Organic Pollutants

    • Organic compounds that are resistant to environmental degradation.

    • Many of these pollutants are currently or were previously used as pesticides.

• Radon

  • Invisible, radioactive gas that results from the radioactive decay of radium.

  • Radon is the most pervasive serious hazard for indoor air in the United States and Europe.

• Tobacco Smoke

  • Cigarette smoke contains almost 5000 chemical compounds including 60 known carcinogens.

  • Cigarette smoking and other forms of inhaling tobacco smoke are responsible for 85% of lung cancers.

  • Cigarettes are smoked by about 20% of the world’s population.

Acid Deposition

• Dry Deposition

  • In areas where the weather is dry, acidic chemicals in the air may become incorporated into dust or smoke and fall to the ground.

• Wet Deposition (Acid Rain)

  • Refers to acid rain, fog, and snow.

  • As this acidic water flows over and through the ground, it affects a variety of plants and animals.

  • Acid rain causes acidification of lakes and streams.

  • It causes damage to trees at high elevations and many sensitive forest soils through nitrogen saturation and by creating acidic conditions that are unhealthy for decomposers and mycorrhizal fungi.

  • Acid shock is caused by the rapid melting of snow packs that contain dry acidic particles, resulting in acid concentrations in lakes and streams that are 5 to 10 times higher than that of acidic rainfall.

  • Acid rain accelerates the decay of building materials and paints.

  • Acid rain also leaches essential plant nutrients from the soil.

• Effects of Acid Deposition

  • Increased solubility of toxic metals

  • Increased leaching of soil nutrients

  • Reduced buffering capacity of the soil

  • An increase in fish kills

  • Changes in vegetation

  • Changes in animal life

  • Acid shock

• Remediation and Reduction Strategies

  • Continued support and enforcement of the Clean Air Act

  • Tax incentives to encourage buyers of new vehicles to switch to green vehicles

  • Tax incentives to power companies to encourage them to convert to less polluting sources of energy

  • Requiring the use of pollution control technology for existing coal-burning power plants

  • Requiring that only Energy Star appliances be sold in the US

  • Creating allowance trading systems

  • Requiring continuous emission monitoring systems for industries that are historically heavy polluters.

• Smog

  • There are two forms of smog Industrial and photochemical smog.

  • Industrial smog tends to be sulfur based and is also called “grey smog”

  • Photochemical smog is catalyzed by UV radiation and tends to be nitrogen-based.

  • Industrial Smog

    • Formation of Industrial Smog

      • Carbon in coal or oil is burned in oxygen gas to produce carbon dioxide and carbon monoxide gas.

      • Unburned carbon ends up as soot or particulate matter.

      • Sulfur in oil and coal reacts with oxygen gas to produce sulfur dioxide.

      • Sulfur dioxide reacts with oxygen gas to produce sulfur trioxide.

      • Sulfur trioxide reacts with water vapor to form sulfuric acid

      • Sulfuric acid reacts with atmospheric ammonia to form brown, solid, ammonium sulfate.

  • Photochemical Smog

    • 6AM-9AM

      • As people drive to work, concentrations of nitrogen oxides and VOCs increase.

    • 9AM-11AM

      • As traffic begins to decrease, nitrogen oxides and VOCs begin to react, forming nitrogen dioxide.

    • 11AM-4PM

      • As the sunlight becomes more intense, nitrogen dioxide is broken down and the concentration of ozone increases.

      • Nitrogen dioxide also reacts with water vapor to produce nitric acid and nitric oxide.

      • Nitrogen dioxide also can react with VOCs to produce toxic PANs.

    • 4PM to Sunset

      • The production of ozone is halted.

• Catalytic Converters

  • An exhaust emission control device that converts toxic chemicals in the exhaust of an internal combustion engine into less noxious substances.

  • Inside the converter, a catalyst stimulates a chemical reaction in which noxious byproducts of combustion are converted to less toxic substances by way of catalyzed chemical reactions.

  • Although catalytic converters are effective at removing hydrocarbons and other harmful emissions, they do not reduce the emission of carbon dioxide produced when fossil fuels are used for fuel.

Thermal Pollution

• Thermal pollution is the degradation of water quality by any process that changes ambient water temperature.

• Heat Islands

  • Occur in metropolitan areas that are significantly warmer than their surroundings.

  • Urban air can be warmer than the surrounding air.

  • Reasons for higher urban temperatures are

    • More black asphalt and other building surfaces that absorb heat.

    • Additional impervious materials in urban areas reduce natural cooling

    • Additional heat is produced by burning the fuels necessary for air

    • Buildings interfere with the outgoing thermal radiation emitted by Earth’s surface

    • There is a lack of vegetation and standing water.

  • Human activities that increase the heat island effect include the operation of automobiles, air conditioners, and industry.

• Temperature Inversions

  • Occur when the air temperature increases with the height above the ground.

  • This effect can lead to pollution such as smog being trapped close to the ground with possible adverse effects on human health.

Noise Pollution

• Noise pollution is unwanted human-created sound that disrupts the environment.

• The dominant form of noise pollution is from transportation.

• Effects of Noise Pollution

  • Normal hearing depends on the health of the inner, middle, and outer ear.

  • Sensory hearing loss is caused by damage to the inner ear.

  • Excessive noise can cause cardiovascular problems.

• Noise Control Measures

  • Techniques to Reduce Roadway Noise

    • Create noise barriers

    • Place limitations on vehicle speeds

    • Introduce newer roadway surface technologies

    • Limit times for heavy-duty vehicles

    • Create computer-controlled traffic flow devices.

  • Techniques to Reduce Aircraft Noise

    • Quieter jet engines

    • Reschedule takeoff and landing times

  • Techniques to Reduce Industrial Noise

    • Create new technologies in industrial equipment

    • Install noise barriers

Water Pollution

• The contamination of water bodies.

• This form of environmental degradation occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds.

• Sources of Water Pollution

  • Sewage

  • Farm runoff

  • Air pollutants

  • Industrial wastewater

  • Shipping

  • Offshore Oil

  • Litter

• Air Pollution

  • Pollutants from the air fall into the water.

  • This can cause mercury contamination in fish and the acidification of lakes.

  • The oceans have absorbed enough carbon dioxide to have already caused a slight increase in ocean acidification.

• Assorted Chemicals

  • A variety of chemicals from industrial and agricultural sources can cause water pollution.

  • Pollutants accumulate in fish and shellfish poisoning people, animals, and birds.

  • Drilling and extraction operations for oil and gas can also contaminate coastal waters and groundwater.

• Cultural Eutrophication

  • The process whereby human activity increases the amount of nutrients entering surface waters.

  • Human Activities that contribute to Cultural Eutrophication

    • Fertilizers and pesticides from residential and agricultural runoff

    • Discharge from water treatment facilities that don’t have the capacity to handle nutrient and biodegradable waste discharge

    • Use of household products that contain phosphates

    • Sewer and drainage overflows that can occur when the rainfall amount excess the wastewater treatment capacity

  • Steps for controlling Cultural Eutrophication

    • Planting Vegetation along stream beds

    • Constructing wastewater lagoons and retention ponds

    • Controlling the application of fertilizer

    • Controlling runoff from feedlots

    • Updating building codes to utilize permeable pavement to absorb excess urban runoff

    • Using monetary and tax incentives to convert existing watering systems to drip irrigation.

    • Upgrading existing water treatment plants.

• Biodegradable Wastes

  • The release of biodegradable wastes into receiving waters is also a major component of cultural eutrophication.

  • These wastes are used by bacteria and microorganisms.

  • This can increase anaerobic bacteria.

  • These cause dead zones, which occur in bottom, and near bottom, water near inhabited coastlines, where aquatic life is most concentrated.

• Microbiological

  • Disease causing microorganisms can result in swimmers getting sick and fish and shellfish becoming contaminated.

  • In developing countries, ~90% of wastewater is discharged directly into rivers and streams without treatment.

  • In the US, almost a trillion gallons of raw sewage is dumped into rivers, lakes, and bays each year.

  • About 25% of beaches in the US have annual water pollution advisories or are closed each year due to bacterial buildup.

• Mining

  • Mining causes water pollution in a couple ways.

    • The mining process exposes heavy metals and sulfur compounds that were previously locked away in the Earth. Rainwater leaches these compounds out of the Earth, resulting in acid mine drainage and heavy-metal pollution.

    • The rainwater falling on piles of mining waste transfers pollution to freshwater supplies.

    • In gold mining, cyanide is poured onto piles of mined rock to extract the gold from the ore. Some cyanide makes its way into nearby water.

    • Mining companies in developing countries often dump mining waste directly into rivers or other bodies of water.

• Noise

  • Many marine organisms use sound to communicate, navigate, and hunt.

  • Because of oceanic water noise pollution, some species may have a harder time hunting, navigation, or detecting predators.

• Oil Spills

  • Oil is one of the world’s main sources of energy, but it must be transported by ships across oceans to distribute worldwide.

  • Oil that is accidentally released into a marine environment can affect wildlife:

    • Oil penetrates the feathers of seabirds.

    • Impairs seabirds flight and their abilities to forage and escape from predators.

    • Seabirds ingest oil that covers their feathers causing kidney and liver damage.

    • Less sunlight penetrates into the water, limiting photosynthesis of marine plants and phytoplankton.