Unit 8 "Ecology Chemistry": Lesson 4 "Ecology Chemistry Portfolio"
Chemical contaminant rules are intended to protect people from the risk of major waterborne hazards that can cause...
- cancer - organ damage - circulatory system disorders - nervous system disorders - reproductive system disorders
When measuring pollution, scientists often test for...
- dissolved oxygen (too little oxygen can kill aquatic organisms) - pH (extremes of acid or base can injure both plants and animals) - temperature (high temperatures from industry can injure aquatic organisms) - salinity (salinity in freshwater is a form of pollution) - nutrients (too much nitrogen and/or phosphorus leads to overgrowth of algae and fungus) - turbidity (quantity of particles of pollutants in water)
Scientists may also test for specific contaminants. For example, they may test for
- microorganisms, such as bacteria that can cause disease - toxins, such as arsenic - pharmaceuticals, such as antibiotics, which can harm both humans and animals
To model water quality, scientists use mathematical information about
- the amount of contaminant already in a body of water - the amount of contaminant flowing into the water - the speed at which the water moves - interactions with other bodies of water - weather (rain, floods, etc.) - interactions with other chemicals
How does passage of time impact the quality of the water in the video?
Chlorine in the water is removed through the use of a charcoal filter. The longer the filter is used, the more chlorine it absorbs.
How did the student test for chlorine in the video?
He used chlorine testing strips that turned colors to show how much chlorine was in the water.
How does mathematical modeling help ensure water quality?
Modeling helps scientists predict changes in the level of a given contaminant over time.
What are three types of water pollution that scientists measure?
Sample answer: level of acidity, quantity of oxygen in the water, level of nutrients, types and number of microorganisms, toxins, pharmaceuticals, salt
What are three measurement units or scales that might be used to describe a pollutant in water?
Sample answer: parts per million, temperature, pH
Why might a scientist measure the temperature of water?
Sample answer: to determine whether the water is so hot that it is likely to injure aquatic life
Why might the measurements of water quality made in the video be unreliable?
The chlorine strips were never tested for accuracy.
contaminant
a polluting (often poisonous) substance that makes something impure, it may be physical, chemical, or biological in nature
Environmental Protection Agency (EPA)
an agency of the United States federal government whose mission is to protect human and environmental health
activated carbon
carbon that is physically or chemically processed to increase porosity and therefore surface area; often used in filtration mechanisms; also known as activated charcoal
concentration
the amount of a substance in a defined space; or the ratio of solute in a solution to either the solvent in the solution or to the total solution
Why does the EPA determine limits of contaminants in water?
to protect the health of humans and animals
