APES Unit 8 | AP Exam Review

Point Source Pollution

Pollution that enters the environment from a single source & is clearly identified

• Wastewater treatment plants

• Electronic or automobile manufacturers

• Paper or pulp mills

• Oil refineries

• Concentrated animal feeding operations (CAFO)

• Leaking underground gasoline storage tanks

Controlling Point Source Pollution

• Clean Water Act requires industries of point sources to get a permit from the state &/or EPA before they can discharge any effluent into a body of water

• Point source will also have to use effective technologies to treat the effluent before it can be discharged

Nonpoint Source Pollution

Pollution that can't be traced back to a single point or property

• Contributions of contaminants come from many sources accumulating over a wide area & eventually reaching a level that impairs water quality

Coral Reefs

Critical ecosystem in the oceans cover less than 1% of the area but support 25% of marine species

• Animals that live symbiotically w/ algae that photosynthesize

Destructive Fishing Practices

• Bottom trawling

• Marine debris

• Overfishing

• Cyanide fishing

Bottom Trawling (Destructive Fishing Practices)

Scrapes nets along the ocean floor & breaks & crushes coral

Marine Debris (Destructive Fishing Practices)

Unattended nets, traps, & monofilament fishing line can damage & injure reefs & reef-dependent organisms like young fish

Overfishing (Destructive Fishing Practices)

Removes fish, especially herbivores, which help maintain healthy algae populations in the reef ecosystem

Cyanide Fishing (Destructive Fishing Practices)

When sodium cyanide is poured over an area to stun fish so they're easier to catch for the aquarium & restaurant trade

Sedimentation Threatens Coral

Soil particles of rock, clay, & sand, can bury corals, blocking the sunlight needed by the symbiont so no photosynthesis can occur, again resulting in the death of the coral

Dead Zone

Excess nutrients (ie. nitrogen & phosphate) from agricultural runoff promotes a bloom of aquatic producers (ie. algae). When they die, they're digested by oxygen-consuming microorganisms

• DO levels decrease to dangerous levels & even death for most organisms

Oxygen Sag Curve

A plot of dissolved oxygen levels vs distance from a source of pollution w/ excess nutrients

Oil Spills Impact Wildlife

• Oil that floats on the surface of the water can coat the feathers of birds, robbing them of both insulation & the ability to fly

• Fur of marine mammals (ie. seals & sea otters) can become saturated w/ oil, inhibiting their waterproofing & ability to maintain their body temp

• They can ingest hydrocarbons as they try to groom the oil from their fur, & like all organisms that ingest or inhale hydrocarbons, die from poisoning

Sediment

Particles of soil, clay, & sand that can be carried from the land to water sources

• Poorly managed construction sites, road building, tilling of farm fields, & overgrazing of riparian habitats can cause this

Heavy Metals in Drinking Water

• Lead

• Arsenic

• Mercury

• Copper

• Cadmium

• Chromium

Can cause cancer, organ damage, & neurological issues

Mercury Health Effects

• Deteriorates nervous system

• Impairs hearing, speech, vision & gait

• Causes involuntary muscle movements

• Corrodes skin & mucous membranes

• Causes chewing and swallowing to become difficult

Microplastics

Tiny, degraded plastic particles & fibers can contribute to toxins to the environment in 2 ways:

• Release of endocrine-disrupting chemicals (ie. BPA) added to plastic polymers when they're produced

• Chemicals like pesticides cling to the tiny particles & are then ingested by plankton & other organisms

Synthetic Chemicals (Endocrine Disruptors)

Industrial solvents/lubricants & their byproducts

• Polychlorinated biphenyls (PCBs)

• Polybrominated biphenyls (PBBs)

• Dioxins

Plastics & plastizers

• Bisphenol A (BPA)

• Phthalates

Pesticides & fungicides

Pharmaceuticals

Natural Chemicals (Endocrine Disruptors)

In foods

• Photoestrogens found in soy

Endocrine System Function

Any chemical that interferes w/ the production, transport, metabolism, or function of hormones in bodies

• Hormones are associated w/ homeostasis, reproduction, & development

Endocrine Disruptors

Can mimic the structure of a signaling chemical that would normally bind w/ a cell receptor to trigger a cellular response

• Can block the signal from reaching the receptor or block the transduction cascade

• Consequences: Reproductive abnormailities, birth & developmental defects, or possible behavioral changes

Endocrine Disrupters in Aquatic Systems

Chemicals enter waterways & bioaccumulate in organisms & biomagnify in the food chain so that top-level consumers are most impacted

• People, predatory fish, & amphibians that consume high numbers of prey w/ endocrine disruptors in their body tissue will accumulate high levels of the chemicals

Wetlands

Defined as having water covering the soil or is near the surface of the soil for all, or most of, the year

• Includes coastal (tidal) & inland (non-tidal)

Coastal (Tidal) Wetlands

Have fluctuating salinity & water levels as they're influenced by the tides

Inland (Non-Tidal) Wetlands

Along rivers & floodplains, in depressions or low-lying areas near lakes & ponds & often have a seasonal nature to them

Biological Productivity in Wetlands

• Shallow water & plenty of plants allow for diverse habitats for animals & birds

• Nutrient-rich soils enhance plant growth which in turn provides food for diverse & abundant species

Wetland Water Purification

• Filtering

• Flood control

• Shoreline stabilization

• Groundwater replenishment

Mangroves (Tidal Wetlands)

• Living in a variety of saltwater conditions

• Providing shelter & food for a host of species

• Can absorb 4 times the carbon dioxide that upland forests can

Threats to Wetlands

• Development of commercial properties

• Dam construction

• Overfishing

• Agricultural & industrial operations

Wetlands Protection & Restoration Act

A U.S. act that highly regulates development in wetlands

Dam Construction (Threat to Wetland)

Restricts & reduces water flowing into wetlands by disconnecting rivers from their floodplains & wetland areas

• Natural downstream flow of sediments that create deltas & build up estuaries along coasts is reduced

• Migration of fish & other species is impacted

Overfishing (Threats to Wetlands)

People harvest fish faster than they can be replenished by reproduction in the population

• Size, age, & type of fish remaining can be altered, creating imbalance in the entire food web within a wetland area

Agricultural & Industrial Operations (Threats to Wetlands)

Excess nutrients & pollutants

• (ie. CAFO)

Sources of Cultural Eutrophication

• Excess fertilizers from farm fields

• Sewage from wastewater treatment

• Nitrogen from animal manure

• Phosphate from detergents

Materials are washed by rain, melting snow, & irrigation into streams, ponds, & lakes

Eutrophic Waterway

• High nutrient levels

• High plant & algae populations

• Low dissolved oxygen

Oligotrophic Waterway

• Low nutrient levels

• Stable plant & algae populations

• High dissolved oxygen

Types of Aquatic Systems

• Stable: An aquatic system w/ a stable amount of algae, aquatic plants, & fish (DO is high)

• Eutrophic: Excess fertilizer where algae grows & reproduces creating a bloom

• Hypoxic: As algae die, they sink to the bottom where oxygen-consuming microbes digest dead cells (Oxygen rapidly consumed by reducing it to dangerously low levels)

Thermal Pollution

When heated water is discharged into bodies of water

Impacts of Thermal Pollution

• Affects survival of eggs & larvae of fish & aquatic insects that have narrow ranges of tolerance

• Die-offs can occur when DO levels are too low

• Feeding, breeding, & migration behaviors can also be altered

DDT

Dicloro-Diphenyl-Trochloroethane

• Insectice

• Colorless crystal

• Banned for use in U.S.

PCBs

Polychlorinated Biphenyl

• Industrial fluid

• Yellow liquid

• Banned for use in U.S.

RCRA

Resource Conservation & Recovery Act

CERCLA

Comprehensive Environmental Response, Compensation and Liability Act

POPs

Persistent Organic Pollutants

• Fat-soluble

• Can travel long distances

Long-Term Effects of POPs

1. Contaminates water & soil for long periods of time

2. Fat-soluble:

   • Accumulate over time

3. Local use of POPs can have a global impact

Bioaccumulation

Process where an organism accumulates a substance in its tissues at a rate faster than it eliminates it, leading to a build-up of the substance over time

Biomagnification

Process where toxins become more concentrated in an organism's tissues as they move up the food chain

Consequences of Biomagnification

1. Organisms at the top of a food chain suffer the greatest effects of toxic substances that bioaccumulate in the body

2. Apex predators

   • Developmental deformities

   • Eggshell thinning, specifically DDT

3. Humans:

   • Learning disabilities, kidney/liver dysfunction, damage to reproductive/circulatory/nervous systems, birth defects

MSW

Municipal Solid Waste

Paper - 27%

Food - 14.6%

Yard Trimmings - 13.5%

Plastics - 12.8%

Metals - 9.1%

Rubber, leather, textiles - 9%

Wood - 6.2%

Glass - 4.5%

Other - 3.3%

E-Waste

Electronic waste

• Contains hazardous chemicals like heavy metals (lead, mercury)

  • Can leach into soil & groundwater

Open Landfill

• Odor

• Poor containment of solid waste & leachate

• Flammable

• Animal disturbances

• Low aesthetic values

Sanitary Landfill

• Liner (clay, plastic)

• Garbage

• Leachate & methane (CH₄) collection/monitoring systems

• When full: cap & continuous monitoring

Solid Waste Management

1. Solid waste comes from many sources: domestic, industrial, business, agricultural

2. Solid waste comes in a variety of categories:

   • E-waste

3. Solid waste most often goes to landfills

4. Sanitary municipal landfill:

   • Bottom liner (clay or plastic)

   • Storm water collection system

   • Leachate collection system

   • Methane collection system

   • Cap when full, w/ monitoring ongoing

5. Anaerobic decomposition produces methane

Alternative Methods of Solid Waste Management

• Incineration

• Illegal terrestrial dumping

• Dumping in ocean

Incineration (Alternative Methods of Solid Waste Management)

Pros: Reduces waste, can be used as energy source

Cons: Solid waste still remains, air pollutants released

Illegal Terrestrial Dumping (Alternative Methods of Solid Waste Management)

Pros: Doesn't take up large space, convenient

Cons: Unregulated methane/leachate emissions, emissions of pollutants associated w/ specific dumped items, disease

Dumping in Ocean (Alternative Methods of Solid Waste Management)

Pros: Convenient, no drawbacks associated w/ landfills

Cons: Impacts marine ecosystems & organisms

Waste to Energy Plant (Landfill Mitigation Strategies)

Sort waste -> Some goes to recycling, rest goes to incinerator -> Waste is burned -> Water boils -> Steam turns turbine -> Turbine turns generator -> Electricity

• Reduces amount of waste in landfill

• Some waste still produced: Ash, hazardous waste, air pollution

Methane Gas Capture & Use (Landfill Mitigation Strategies)

• Decomposition reduces volume of waste in landfill

• Gas can be burned to create electricity

• Some gas can still escape: Greenhouse gas

• Gas is low-quality, requires refining

Cap Full Landfill to Use as Recreational Areas (Landfill Mitigation Strategies)

• Improves aesthetics of area, can be a source of revenue

• Still requires monitoring

Consequences to Poorly-Managed Solid Waste

1. Nonrecycled hazardous waste can pollute surrounding soil & water, even in a landfill

   • Heavy metal toxins: Lead, mercury

2. Reduce/reuse/recycle programs can take solid waste out of the waste stream

3. Dimensional analysis is a key component of math

Sewage Treatment Plans

1. Primary treatment - Physical processes

2. Secondary treatment - Biological processes

3. Tertiary treatment & disinfection - Ecological/chemical processes

Primary Sewage Treatment

Physical Processes

Removal of:

• Sticks

• Rocks

• Rags

• Toys

• Other large objects

Secondary Sewage Treatment

Biological Processes

Bacteria perform aerobic decomposition to break down organic matter

• Aeration

Tertiary Sewage Treatment

Ecological/Chemical Processes

Removes final impurities & pollutants like nitrogen/phosphorus-based chemicals

Disinfection Uses:

• Chlorine

• Ozone

• UV light

Dysentery

Inflammation of the intestines caused by bacteria or parasites

• People can experience bloody diarrhea & abdominal cramping

• Caused by untreated sewage in streams & rivers

  • Contamination can be detected by sampling for fecal coliform in water sources

Mesothelioma

Exposure to asbestos, a type of insulation material, can result in this type of cancer

Asbestos

A natural mineral made of tiny glass-like fibers that are easily inhaled

• Over time, this inflammation damages the cells lining the lungs, heart, & abdomen

Vector

An organism that can transmit diseases between humans & between animals & humans

Spread of Pathogens

• Airborne particles

• Skin contact

• Bodily fluids

• Contact w/ feces

• Touching surfaces that an infected person has touched

• Bite of a vector like mosquito or tick

Pathogen Spillover

When a diseases originates in animals & then spreads to humans

Zika Virus

Can be spread to humans by infected mosquitoes or from sexual contact w/ an infected person

• For most people, the disease symptoms are mild

• If pregnant women are infected, it can cause a severe birth defect (microcephaly) & other severe fetal brain deformities

West Nile Virus

Spreads to humans & other animals (ie. horses) through mosquito bites

• First found in the U.S. during the late 1990s & spread from the east coast to across the country

• Most people have few & mild symptoms from the virus (ie. fever, rash, & fatigue)

• In severe cases, the virus can cause encephalitis, meningitis, & other issues of the central nervous system

Malaria

Caused by Plasmodium, a single-celled parasite (5 species that cause malaria)

• Transmitted through mosquito bites

• Parasite infects your red blood cells & causes them to burst

  • If left untreated, people can develop severe complications & die

• Hundreds of millions of people die yearly

• Disease mostly found in sub-Saharan Africa