Pollution

Dealing with pollution issues: pointing fingers vs finding solutions

economic trade-offs

Life-style considerations

Types of Pollution

1) overloading with biodegradable substrates/nutrients

2) alteration of abiotic conditions

3) synthesis of novel organic materials

Sources of Pollution

1) point sources

2) non-point sources

Overloads

Concentrated additions that overwhelm natural systems

Sewage

Primary: mechanical solids removal

Secondary: biological reduction of organic matter: ≥Activated Sludge≤

Tertiary: nutrient removal

Most systems rely on Nature for tertiary treatment: dead zones

outfall location

≥Grey water≤ use, London, California

Sludge production a problem: agricultural use

Combined storm water and sewage systems

Storm water a complex problem: metals, salts, hydrocarbons, nutrients

leaky collection systems: old lines

Chlorination

Clean Water Act mandates no viable fecal coliforms to be discharged

Fecal Coliforms as indicators

non-point source additions that cause more subtle chronic effects

Agriculture, Professional lawn care, Homeowners

Increased turbidity: seagrasses

BOD, hypoxia/anoxia, eutrophication

Alterations of natural abiotic conditions

noise

heat

desertification

agriculture

Urban/suburban development

co-opted and missing production

Extraction and Concentration of materials:

salts: de-icing problems, irrigation (selenium)

Metals:

chromium, cadnium, copper, lead, mercury ≥Heavy Metals≤

mining activites: acid drainages, tailings ponds, Butte

smelter fumes

(fig 20-13)

flooding of reservoirs, everglades: methyl mecury

Oil:

oil as a natural product: seeps & tar pits

concentration in the wrong place is the problem

EXXON Valdez

Coal extraction, transport

Burning of fossil fuels: metals, acids, PAHπs, CO

Photochemical smog:

Nitrogen oxides + hydrocarbons= Peroxyacetyl nitrate (PAN) + Ozone O₃

products are irritants to mammals, lethal to plants, limits agriculture

ozone increases resiration of leaves: starvation

PAN blocks part of photosynthesis

Acid rain: normal rain 5.6-5.7pH (log scale)

low record 1.4, michigan average 3.9-4.7, east coast <5

5.6 to 5.0 = 4x more acid, 5.6 to 1.4 is 15,800 x

nitrogen oxides and sulfur dioxide Ice core fig. 20-14

Lake effects (table 20-3), dissolution of limestone, metals

attempts to rebuffer streams

often exceeds resilience of natural buffers

Radiation

Background: radionucleotides, cosmic radiation

most mutations lethal: fruit fly mutations

Concentrated sources:

Alpha emitters: low energy, ³H, ¹⁴C

Beta emitters: higher energy, penetrates tissue ³²P

Gamma emtters: ⁶⁰Co, high energy, x-rays

Research, power generation, weapons

processing wastes, ≥used material≤ disposal a problem.

Half life of some more dangerous materials very long

plutonium 24,000 years

Three Mile Island, Chernoble, Nuclear weapons tests/use, terrorism

Synthetic Materials

≥good stuff≤ resistant to decay (entropy), high biological acitivity

styrofoam beads, plastics in the oceans, landfills

Hazardous Wastes: grenades in landfills

PCBπs, Monsanto; PBBπs ≥Poisioning of Michigan≤ J. Agerton

Chlorinated solvents, CFC/preservatives/antiseptics

Dioxins

RCRA 1976

TSCA 1976

Superfund 1980: cleanup and determine responsibility for sites

Clean Water Act 1972

Pesticides: by nature toxic

FIFRA

1) inorganic salts: arsenic, mercury used prior to organic chemcials

2) Organochlorines, organophosphates: 1930-1940πs

3) Hormones, Pheromones, biological control

Synthetics (on handout)

1) Chlorinated Hydrocarbons:

2) Organophophate compounds

3) Carbamates

4) Synthetic pyrethroids

Industrialization of agriculture, economic pressures, pest resistance, wiping out predators with the prey, prey rebound without predators

health concerns: malaria

search for single solutions to complex problems

Rachel Carson: Silent Spring, 1958

integrated pest management a better approach

Monitoring, biologicals, etc.

Homeowner problems

World wide distribution of resistant forms: global poisioning

Sediment Burial; Storms, Dredging problems

Herbicides:

Photosynthesis blockers and defoliants

2,4-D, 2,4,5-T

synthesis contaminant Dioxin more of a problem

Toxicology:

toxic effects:

acute: LD50

chronic: sublethal effects

teratogenic: developmental problems

mutagenic: cancer inducing

hormone disruptors

Bird Eggs, Lake Trout, Bloaters

Bioaccumulation:

especially for resistant fat soluble compounds, DDT

essential minerals in radioactive form: iodine

Determining safe levels for human and ecosystem health:

toxicity testing with model organisms: mice, rats, fish, zooplankton

extrapolation problems

synergysms