Module 47 - Sources of Pollution, Human Impacts on Ecosystems, and Endocrine Disruptors

Point source

distinct location from which pollution is directly produced (ex. smokestack releasing harmful chemicals)

Nonpoint source

diffuse area that produces pollution; large number of relatively small contribution to pollution spread over a large area (ex. farming region, suburban community, storm runoff)

Homeostasis

ability to experience relatively stable internal conditions within an organism's body, with an ideal range for that specific organisms

Lead

Source: water passing through lead-lined pipes

Concerns: fetal brain damage, CNS damage, kidney damage

Removal: remove from gasoline, lead-free pipes/paint, water filtration

Arsenic

Source: mining, contaminated water

Concerns: cancer in skin, lungs, kidney, bladder

Removal: membrane filtration of water, water distillation, reverse osmosis

Mercury

Source: burning coal, incinerating garbage/medical/dental waste; deposition in waterways

Concerns: biomagnification, CNS damage, fetal danger

Removal: reduce coal usage

Pesticides

Source: agricultural industries

Concerns: loss of biodiversity, inert ingredients for faster spread

Removal: rules & regulations to limit the use of pesticides in certain areas

Pharmaceuticals and hormones

Source: untreated wastewater in streams/rivers

Concerns: just beginning to investigate effects of these

Removal: rules & regulations to control disposal

Military compounds

Source: perchlorates from rocket fuel; consumption of contaminated food/water

Concerns: thyroid damage

Removal: membrane filtration, reverse osmosis

Industrial compounds

Source: industrial dumping; PCBs (used to manufacture plastic & insulate electrical transformers)

Concerns: brain damage, cancer

Removal: reduce dumping in waterways

Neurotoxins

chemicals that disrupt the nervous system of animals (ex. lead, mercury)

Carcinogens

chemicals that cause cancer (ex. tobacco smoke, asbestos, radon, formaldehyde)

Mutagens

carcinogens that cause damage to the genetic material of a cell (ex. radioactive substance, x-rays, UV, certain chemicals)

Teratogens

chemicals that interfere with the normal development of embryos or fetuses (ex. thalidomide (morning sickness drug), alcohol)

Allergens

chemicals that cause allergic reactions/trigger unnecessary immune response (ex. peanuts, milk, penicillin, codeine, bee stings)

Endocrine disruptors

chemicals that interfere with the normal functioning of hormones in an animal's body (ex. reproductive hormones in wastewater interfering with production of testosterone in animals)

Wastewater

water produced by livestock operations, sewage, and gray water

Exxon Valdez

rock cracked hull of tanker, spilling 42 million liter of crude oil; 250,000 seabirds, 2,800 otters, 300 harbor seals, and 22 killer whales were killed

Deepwater Horizon

offshore platform explosion with broken pipe and spilled 780 million liters of crude oil; contaminated beaches, wildlife, and estuaries; one of the worst environmental disasters of the world

Vacuum pumps

contain spill within an area (plastic barriers) & use giant vacuums to suck up oil off surface of water; absorbent materials used in shallow water

Treating oil with dispersals

chemicals that break up & disperse oil before it reaches shorelines; can sometimes be toxic to marine life

Burn the oil

light it on fire; burns away large amounts quickly, also dangerous and destructive

Genetically engineered bacteria

use bacteria that consume oil as an energy source to "eat" oil spill; needs more research