How much is too much?

Minor Spill in Local Minor Spill in Local WatershedWatershed

Yesterday a loaded sewage truck slid off the Yesterday a loaded sewage truck slid off the bridge crossing the Clearwater River. The bridge crossing the Clearwater River. The truck’s contents spilled into the river and due to truck’s contents spilled into the river and due to the swift current, the sewage was carried away the swift current, the sewage was carried away before clean-up crews could be dispatched. before clean-up crews could be dispatched. Today, at the Rocky Mountain House treatment Today, at the Rocky Mountain House treatment plant, located at the junction of the Clearwater plant, located at the junction of the Clearwater and North Saskatchewan Rivers, an e-coli and North Saskatchewan Rivers, an e-coli concentration of 0.00001 ppth was detected.concentration of 0.00001 ppth was detected.

Spill in Local River – Spill in Local River – Effects UnknownEffects Unknown

Yesterday a loaded sewage truck slid off the Yesterday a loaded sewage truck slid off the bridge crossing the Clearwater River. The bridge crossing the Clearwater River. The truck’s contents spilled into the river and due to truck’s contents spilled into the river and due to the swift current, the sewage was carried away the swift current, the sewage was carried away before clean-up crews could be dispatched. before clean-up crews could be dispatched. Today, at the Rocky Mountain House treatment Today, at the Rocky Mountain House treatment plant, located at the junction of the Clearwater plant, located at the junction of the Clearwater and North Saskatchewan Rivers, an e-coli and North Saskatchewan Rivers, an e-coli concentration of 10 ppb was detected.concentration of 10 ppb was detected.

Catastrophic Events May Catastrophic Events May Change Local River Change Local River ForeverForever

Yesterday a loaded sewage truck slid off the Yesterday a loaded sewage truck slid off the bridge crossing the Clearwater River. The bridge crossing the Clearwater River. The truck’s contents spilled into the river and due to truck’s contents spilled into the river and due to the swift current, the sewage was carried away the swift current, the sewage was carried away before clean-up crews could be dispatched. before clean-up crews could be dispatched. Today, at the Rocky Mountain House treatment Today, at the Rocky Mountain House treatment plant, located at the junction of the Clearwater plant, located at the junction of the Clearwater and North Saskatchewan Rivers, an e-coli and North Saskatchewan Rivers, an e-coli concentration of 10 000 ppt was detected.concentration of 10 000 ppt was detected.

After reading the three newspaper After reading the three newspaper articles, which “event” will have the articles, which “event” will have the greatest effect on the environment? greatest effect on the environment? Why???Why???

What is a pollutant?

-- any material/form of energy that will any material/form of energy that will cause harm to a living organismcause harm to a living organism

-- can be a physical, chemical, or can be a physical, chemical, or biological harm that threatens the health biological harm that threatens the health or survival of that organismor survival of that organism

What is pollution?

-- any alteration of the environment any alteration of the environment producing a condition that is harmful to producing a condition that is harmful to living thingsliving things

How do we express concentrations of pollutants?

-- ppm – 1 mg/kgppm – 1 mg/kg -- ppbppb -- even ppt – cadmium becomes toxic at even ppt – cadmium becomes toxic at

17 ppt (heavy metals – density of 5 g/cm17 ppt (heavy metals – density of 5 g/cm33) 1 quarter in a stack 2000 km high!!1 quarter in a stack 2000 km high!! -- percent – food (fat in milk)percent – food (fat in milk)

Toxicity

-- the ability of a material to cause the ability of a material to cause harm to an organismharm to an organism

-- acute – serious symptoms after only acute – serious symptoms after only one exposureone exposure

-- chronic – symptoms appear after chronic – symptoms appear after extended exposureextended exposure

LD50 – lethal dose 50

- a common measurement of toxicity refers the dose of a chemical that will kill

50% of the tested population

Acceptable Risk

What is considered acceptable? -- pros outweigh the conspros outweigh the cons -- toxicity different for different peopletoxicity different for different people -- tests rarely done on humanstests rarely done on humans -- results are guesses from lab results are guesses from lab

rat/mice informationrat/mice information

Thalidomide

treatment of insomnia, lupus, and arthritis -- caused birth defects – lack caused birth defects – lack

of/severely shortened limbsof/severely shortened limbs

Saccharin

sweetener (Sweet n’ Low) - discovered in 1879 – 500 times

sweeter than sugar - produces cancer in some lab

animals

Evaluation of Risk

-- most poisons are natural (called toxins)most poisons are natural (called toxins) -- for every 1 molecule of man-made for every 1 molecule of man-made

pesticide in our diet, there are 10 000 pesticide in our diet, there are 10 000 molecules of natural pesticides that we ingest.molecules of natural pesticides that we ingest.

-- Fungicides sprayed on crops can cause Fungicides sprayed on crops can cause cancer, however, molds that grow on crops is cancer, however, molds that grow on crops is also carcinogenic. also carcinogenic.

Monitoring the Monitoring the EnvironmentEnvironment

Biological indicators Biological indicators – aquatic – aquatic invertebrates, types of fish, top of the invertebrates, types of fish, top of the food chain, microbiological indicatorsfood chain, microbiological indicators

Chemical factors Chemical factors – dissolved oxygen, – dissolved oxygen, acidity, heavy metals, pesticides, plant acidity, heavy metals, pesticides, plant nutrients, saltsnutrients, salts