The Air We Breathe
Ozone (O^3)
- Sharp odour - may reduce lung function - chest pain, coughing, sneezing, lung congestion - yellows pine needles - at high altitude it plays essential role in screening out UV radiation
Nitrogen dioxide (NO^2)
- brown colour - dissolves in moist lung tissue producing acid - produced from nitrogen monoxide, produced in air from heat, i.e. engines and coal-fired power plants - may injure and kill inhalers
Particulate matter (PM)
- complex mixture of tiny solid particles and mini liquid droplets - classified by size rather than composition
Sulfur dioxide (SO^2)
- sharp, unpleasant odour - dissolves in moist tissue of lungs forming acid - burning of coal - causes respiratory distress, heart failure, asphyxiation, lung damage
Composition of air
78% N 21% O 1% Ar
Catalyst
A chemical substance that participates in a chemical reaction and influences its rate without self undergoing permanent change; speeds up a chemical reaction
Mixture
A physical combination of two or more pure substances in variable amounts
Chemical reaction
A process whereby substances described as reactants are transformed into different substances called products
Chemical equation
A representation of a chemical reaction using chemical formulas
Oxygen (O)
Absorbed via lungs and reacts with foods to release energy to power chemical processes in our bodies. Essential component for breathing
Exposure
Amount of substance encountered. Depends on easily measured factors: - Concentration of air - Length of time - Rate of breathing
Combustion
Chemical process of burning, the rapid reaction of fuel and oxygen to release energy in the form of heat and light
Argon (Ar)
Chemically inert ("lazy" in Greek) What you inhale you simply exhale
Clean Air Act 1970
Established national air quality standards in USA
Pollution Prevention Act 1990
Followed Clean Air Act, focusing on preventing formation of hazardous substances i.e. 'logic of prevention'
Law of conservation of matter and mass
In a chemical reaction, matter and mass are conserved, the mass reactants consumed equals the mass of the products formed
Troposphere
Lowest layer of atmosphere, where 75% of air we breathe lies
Ecological footprint
Means of estimating the amount of biologically productive space (land and water) necessary to sustain a particular standard of living/lifestyle
Sustainability
Meeting the needs of the present generation without compromising the ability of future generations to meet their own needs - 1987 Our Common Future WCEDUN
Metal, Nonmetal, Metalloid
Metal: elements that conduct electricity and heat Nonmetal: do not conduct heat or electricity and have no characteristic appearance Metalloid: lie between metals and nonmetals
Nitrogen (N)
Most abundant substance in air; colourless, odourless, un-reactive, passes in/out of lungs unchanged
Risk assessment
Process of evaluating scientific data and making predictions in an organized manner about probabilities of an outcome
Compound
Pure substance made up of two or more elements in a fixed, characteristic chemical combination
Element
Pure substance which compounds are formed
Air Quality Index
Scaled from 1-500, with value of 100 pegged to national standard for a pollutant
Scientific notation
Scientific system of writing numbers as a product of with 10 and raised to the appropriate power
Respiration
The foods we eat are metabolized to produce carbon dioxide (CO^2 and water)
Toxicity
The intrinsic health hazard of a substance
Triple Bottom Line
Three way measure of success of a business 1) Profit 2) Fair & beneficial 3) Healthy for environment
VOCs
Volatile Organic Compounds: - carbon containing compounds that easily evaporate
Tragedy of the Commons
When a resource is common to all and used by many, but has no one in particular responsible for it. As a result, it may be destroyed by overuse and costs are shared by all
ppm
parts per million
Carbon Monoxide (CO)
'Silent killer' - no colour, taste, smell --> when inhaled, causes nausea, dizzyness, headaches Released by automobiles, charcoal grills, propane camping stoves
