APES Unit 8 - Aquatic and Terrestrial Pollution

8.1 Sources of Pollutants

  • Point Source: Pollutant enters the environment from a single, identifiable location.
  • Nonpoint Source: Pollutants enter the environment from multiple, diffuse locations.
  • Examples:
    • Point: Animal waste runofffrom a CAFO, emissions from a smokestack.
    • Nonpoint: Urban runoff, pesticides sprayed on fields.

8.2 Human Impacts on Ecosystems

  • Organisms have a range of tolerance for abiotic conditions like pH, temperature, salinity and pollutants.
  • Pollutants can cause:
    • Limited growth & reproductive function.
    • Difficulty in respiration and hormonal disruption ultimately leading to death.

pH Tolerance

  • When pH decreases outside optimal range for species, population declines.
  • Acid rain Low pH can lead to aluminum toxicity and disrupted blood osmolarity.
  • Indicator species can be surveyed to determine ecosystem conditions. Ex: high whitemoss indicates pH < 6.0 and crustaceans pH > 6.0

Temperature Tolerance of Reef Algae

  • Coral reefs have mutualistic relationship with algae.
  • Algae have narrow temp. tolerance and leave the reef when temp. rises can be caused by greenhouse gas emissions.
  • Coral lose color & are stressed without algae.
  • Sediment pollution, toxicants, and nutrients from runoff causes decline in aquatic environment.

Oil spill effects

  • Hydrocarbons in crude oil are toxic to marine organisms.
    • Decreased visibility and photosynthesis.
    • Oil on bird feathers affecting Tourism and Fishing Industry revenue, hurt restaurants that serve fish

Oil Spill Cleanup

  • Cleanup methods include booms, vacuum tubes, physical removal, and chemical dispersants.
    • Note: chemical dispersants can harm bottom-dwellers and may be harmful themselves.

8.3 Endocrine Disruptors & Industrial Water Pollutants

  • Endocrine disruptors are chemicals that interfere with the endocrine system of animals, leading to birth defects and gender imbalances.
  • Sources Human medications, atrazine.

Mercury

  • Bacteria convert mercury to methylmercury, which is highly toxic.
  • Mercury comes from Coal combustion, trash incineration, burning medical waste, heating limestone for cement

Arsenic & Lead

  • Arsenic: Carcinogenic and endocrine disrupting.
  • Lead: Neurotoxicant; impacts central nervous system.
  • Water filters can remove Arsenic and Lead.

Coal Ash

  • Can leach into groundwater, contaminating it with arsenic, lead, mercury.

4.6 Watersheds

  • Watershed: All land that drains into a specific body of water.
  • Characteristics: Area, length, slope, soil, vegetation types.
  • Vegetation, soil, slope = impact on drainage.
  • Human activities (agriculture, clearcutting, urbanization, dams, mining) impact water quality.

Chesapeake Bay Watershed

  • Mix of fresh & salt water + nutrients in sediment make estuary habitats, Ecosystem serevices: Tourism, water filtration and storm protection.
  • N/P pollution leads to eutrophication in the Bay.
  • Sources: Sewage treatment plants, animal waste, synthetic fertilizer.
  • Other pollutants: Endocrine disruptors, sediment pollution.

Direct Effects of Clearcutting

  • Soil erosion and increased soil & stream temperature.

Watershed Pollutant Solutions

  • Riparian buffers, enhanced nutrient removal, animal manure management, cover crops, septic tank upgrades

8.4 Human Impacts on Wetlands and Mangroves

  • Wetlands: Area with soil submerged/saturated in water, has ecosystem services. Provisioning: habitat, regulating groundwater recharge, supporting: H2O filtration, cultural: torism
  • Threats: Pollutants, water diversion, dam construction, overfishing, and development.

8.5 Eutrophication

  • Extra N & P leads to growth of algae which covers surface of water, lower O2 levels in water kills aquatic animals.
  • Anthropogenic nutrient pollution increase of N/P comes from Sewage treatment plants, animal waste from CAFOS, synthetic fertilizer from ag. fields & lawns

Oligotrophic Waterways

  • Low nutrient levels high dissolved oxygen. Can be due to lack of nutrient pollution, or age of the body of water

Dissolved Oxygen & Dead Zones

  • Decrease in dissolved oxygen (hypoxia) is what causes a dead zone, Few species can be supported. Most fish need 3.0 ppm to survive.

8.6 Thermal Pollution

  • Inverse relationship between water temp & oxygen solubility.
  • Thermal pollution: heat released into water with negative effects.
  • Heat increases respiration and decreases O2 which leads to suffocation.
  • Sources: Power plants, steel mills, paper mills, nuclear power plants.
  • Cooling towers are used to cool steam back into water before discharge.

Persistent Organic Pollutants

  • POPs: Synthetic compounds that don’t easily breakdown in the environment.
  • Accumulate in fat tissue, impacting brain & reproductive system.
  • Sources: Pesticides, PCBs, PBDEs, dioxins, phthalates.
  • POPs travel long distances through wind & water.

Biomagnification

  • Is Increase of concentration of substances per unit of body tissue levels of a food chain or in a food web.
  • Organisms at each successive trophic level need to eat more and more biomass to receive enough energy, leading to higher and higher POP levels over their lifetimes.
  • Large predators like salmon, dolphins, and whales have highest POP/methylmercury levels

Biomagnification examples DDT and Mercury

  • DDT: banned in many developed nations, but still exists in bodies of water.
  • Mercury: emitted from burning coal. Human exposure to methylmercury comes from eating large predatory fish.

LD50 & Dose Response Curve

  • LD50: Dose of a chemical that is lethal to 50% of the population.
  • Dose response curve: describes the effect on an organism based on the dose of a toxin or drug.
    Threshold point on the graph, is defined as the lowest dose where an effect starts to occur.
  • Usually divide LD50 or ED50 dose concentration by 1,000 to determine maximum allowable levels for humans.

Solid Waste Disposal

Solid waste includes trash and e-waste, which can leach chemicals.
Sanitary landfills have a bottom liner, leachate & methane collection systems, and a cap.
Landfill decomposition is low due to lack of O2 and moisture.
Incineration volume by 90%, releases air pollutants and Some items like tires are not accepted.

Sewage Treatment

  • Solid Waste Types and Sources divided by Municipal Solid Waste and E-Waste, which can leach endocrine disrupting chemicals out of landfills if thrown away with regular MSW

8.10 WASTE REDUCTION

  • reduce Reuse, Recycle.
    reduce consumption to decrease harvest energy. Recycling reduces demand for new materials, conserves landfill space and The combustion of gases produced from decomposition of organic material in landfills can be used to turn turbines and generate electricity to reduce landfill volume by reducing methane. . But It is the Least sustainable due to the amount of energy it requires processing.

Composting

  • Decomposing organic matter under controlled conditions to produce soil that can hold water.

E-Waste

  • Electronics with heavy metals and Often sent to developing nations where it is often burned or dumped into soil

Sewage Treatment

Effluent: liquid waste from treatment plant.

Water Treatment Process

  • Primary Treatment: physical removal of large debris using screens.
  • Secondary Treatment: biological breakdown of organic matter.
  • Tertiary Treatment: ecological or chemical processes to remove pollutants.
    -Final water is disinfected: UV light, ozone, or chlorine to kill bacteria

Primary, Secondary and teritary Treament in detail.

primary Treatment: screens to remove debris, sludge that accumulates at the bottom.
Secondary Treatsment the aerated tanks filled with bacteria that breaks down org. into N and P
teritaryTreatment: Chemical filters used to reduce more Nutrients.

Sewage Treatment Issues

  • Combined sewage and stormwater runoff systems can cause wastewater treatment plants to flood.
    Even treated wastewater effluent released into surface water often has elevated N/P levels and endocrine disruptors.

Pollution and Human Health

  • Synergism: Interaction of substances to cause a greater effect than individual.
  • Routes of Exposure: Pollutant enters the body from:Lead from water pipes. Mercury from fish, CO,PM, Arsenic and rice.

Human disease from pollution

  • Dysentery: Bacterial infection from feces contamination to streams = dehydration.
  • Mesothelioma: cancer from asbestos exposure (old insulation materials).
  • Tropospheric Ozone (O3) causes :Worsens asthma respiratory conditions, from photochemical breakdown of NO2

8.15 Pathogens and Infectious Diseases

  • Pathogens are infectious and infectious diseases are capable of being spread or transmitted. and
  • Vectors: A living organism (rat, mosquito) that carry and transmit infectious pathogens to other organisms. Which can be expanded as equitorial shifts bringing warmer weather, many pathogenic bacterial , viruses survive and replicate better in warmer weather

Infectious Disease & Development

  • Less developed have higher rates of disease.
  • Less sanitary waste disposal,
    Treatment/filtration for drinking water &
    Access to healthcare facilities

Pathogen infections

  • Plague From fleas (vector) that attach to mice & rats.
    -TB From bacterial (pathogen) infection that targets the Lungs
  • Malaria parasitic protist (pathogen)From infected mosquitoes with flu-like symptoms
    West & Nile Virus Virus from mosquitoes that bites infected birds and then bite humans,Causing brain inflammation, Zika Virus infection from mosquitoes ,Causes babies to be born damaged and MERS and SARS are viral diseases while Cholera is bacterial.