Air, Water and Land Pollution
Chapter 1:
Introduction
Copyright © 2009 by DBS
Contents
•
•
•
•
What is Pollution Science
The Chemicals of Interest
Units of Concentration
Sources
Introduction
What is Pollution Science?
Two key components to the definition of pollution:
1. Pollution involves a change to an environment
e.g. addition of man-made chemicals that do not occur naturally*
2. The environment must be perturbed in a harmful way
* This is not to say that naturally occurring chemicals are always good!
They may be present at levels over and above what is healthy (criteria 2)
Introduction
What is Pollution Science?
Not all pollutants are chemicals!
What are some other examples?
Here is a hint!
This 1988 thermal image of the Hudson River highlights
temperature changes caused by discharge of 2.5 billion
gallons of water each day from the Indian Point power
plant. The plant sits in the upper right of the photo —
hot water in the discharge canal is visible in yellow and
red, spreading and cooling across the entire width of
the river.
Two additional outflows from the Lovett coal-fired power
plant are also clearly visible against the natural
temperature of the water, in green and blue.
Introduction
What is Pollution Science?
•
Aquatic Life
– Decreased ability of water to hold oxygen
– Increased rate of chemical reactions
– Changes in reproduction, behavior and growth throughout the food chain
– Long-term damage to natural waters
•
Temperature is one of the most important factors governing the occurrence and behavior of life
Ecological Effects of Thermal Pollution
Introduction
What is Pollution Science?
Ecological Effects of Thermal Pollution
•
•
•
•
One famous case is that of Sockeye Salmon - Columbia River
A series of hydroelectric dams changed it from cool/fast-flowing
to warmer/slower moving lakes
Bacterial diseases drastically reduced the population
Listed as US endangered species
Total commercial landings of chinook and sockeye
salmon in the Columbia River, 1866-1990
(from NPPC 1986, ODFW and WDF, 1991)
Introduction
What is Pollution Science?
Introduction
What is Pollution Science?
Environmental Compartments
Introduction
What is Pollution Science?
•
•
•
Can be subdivided further
May have interactions between compartments
Contaminants may behave very differently in each compartment e.g. have
different lifetimes (residence times), exchange rates and mobility
Introduction
What is Pollution Science?
•
When the flow of a substance into a system is equal to the outflow then the amount of substance
will be constant – equilibrium or steady-state
•
Average amount of time a substance exists before it is removed is defined as follows:
Residence time (τ) =
amount of substance in the ‘reservoir’ (M)
rate of inflow to, or outflow from, reservoir (F)
•
Must be distinguished from half-life, residence time is the time taken for the substance to fall to
1/e (~37%) of the initial concentration
•
Important for determining whether a substance is widely distributed in the environment c.f. CFC’s
and acidic gases
Question
A college has a constant undergraduate enrollment of 5,000 students. No students
flunk out or transfer in from other colleges and so the residence time of each student
is four years. How many students graduate each year?
Residence time =
amount of substance in the ‘reservoir’
rate of inflow to, or outflow from, reservoir
4 yrs = 5,000 / rate of outflow
Rate of outflow = graduation rate = 5,000 /4 = 1250 students / yr
In this problem all students have the same residence time. In the case of pollutants
residence time is an average of all the molecules and each individual molecule has
different residence times
Introduction
What is Pollution Science?
Residence time: For a 1st order reaction:
C = C0e-kt
When t = τ = 1/k
C = C0e-1 =
C = 0.37 C0
1 x C0
e
(where e = 2.718..)
Introduction
What is Pollution Science?
• Half-life: Time taken for the concentration in the reservoir to fall by
50%
• When C = C0/2
C = C0e-kt
C0/2 = C0e-kt
e-kt = ½
τ1/2 = ln 2
k
Introduction
What is Pollution Science?
•
Monitoring:
–
–
Chemical analysis
Biological monitoring
•
Pros/cons: Bio-monitoring is not specific to a single substance, chemical
monitoring cannot establish an adverse effect only a concentration
•
Two methods are complementary
Introduction
What is Pollution Science?
•
To understand the behavior of pollutants in the environment and
appreciating their effects on the environment and on humans, and to
monitor and manage those pollutants
•
A grounding in which sciences is required?
Introduction
The Chemicals of Interest
•
•
•
Pollution and pollutant
– Preferred by environmentalists and EPA
Contamination and contaminant
– Preferred by US DOE
Legal defination specifies concentration and location
Introduction
The Chemicals of Interest
Inorganic
Metals
Metalloids
Radioactive
Organic
Non-metals
Chemical type:
Heavy
Metals
Make
connections
Transition
Metals
Toxic
Non-Toxic
Introduction
The Chemicals of Interest
Inorganic
Metals
Metalloids
Radioactive
Organic
Non-metals
Chemical type
Heavy
Metals
Transition
Metals
Toxic
Non-Toxic
Introduction
The Chemicals of Interest
3 main categories:
(a) Chemicals of concern because of their human toxicity
(b) Chemicals which cause damage to non-human biota but are not believed to harm
humans at current levels of exposure
(c) Chemicals not directly toxic to humans or other biota at current environmental
concentrations, but capable of causing environmental damage
Introduction
The Chemicals of Interest
3 main categories:
(a) Chemicals of concern because of their human toxicity
e.g. Pb, Cd, Hg, As have known effects
No known essential role in the human body
Tolerated at
low-exposure
Toxic symptoms
Fig. 1:
Introduction
The Chemicals of Interest
3 main categories:
(a) Chemicals of concern because of their human toxicity
essential trace elements behave very differently
Acceptable range
Deficiency if
low-exposure
Toxic symptoms
Introduction
The Chemicals of Interest
Body burdens of lead in ancient people uncontaminated by industrial lead (left); typical
Americans (middle); people with overt clinical lead poisoning (right). Each dot represents
40 µg of lead.
Source: Patterson et al., 1991; adapted from NRC, 1980.
Case Study
Minamata, 1953
•
•
•
•
•
WHO limit 0.5 mg kg-1
Minamata 50 mg kg-1
•
Minamata Bay, Japan (1953-1960)
Plastic manufacturer (Chisso Corp.), used mercury in the
production of acetaldehyde
Discharged methyl mercury into the bay
Main diet of locals was fish + shellfish
– 5-20 ppm (106 water)
Over 3,000 people suffered (730 deaths):
Minamata disease / Dancing Cat Disease
various deformities, damage to nervous system, retardation or
death
Developing embryos are especially vulnerable
Health Effects
Mode of Action
• Hg dissolves neurons
http://commons.ucalgary.ca/mercury/
Introduction
The Chemicals of Interest
•
•
Chromated copper arsenate (CCA)
used to protect wood (45% As2O3)
Concern over leaching of As
especially in childrens playgrounds
In 2004 EPA banned CCA
from residential use
Source: http://www.sptimes.com/News/031101/State/The_poison_in_your_ba.shtml
Introduction
The Chemicals of Interest
•
•
•
•
e.g. Fluoride has a narrow window of optimal exposure
Water is fluorinated to 1 mg L-1
Half this concentration may result in deficiency syndrome and weakened
teeth
Double this concentration can lead to adverse effects on teeth and bones
Introduction
The Chemicals of Interest
•
e.g. chemical carcinogens
benzene, polynuclear aromatic hydrocarbons, dioxins, polychlorinated biphenyls
(d) polychlorinated biphenyl
(d)
Introduction
The Chemicals of Interest
•
Dioxins - Agent Orange
Herbicide (defoliant) ~ 10 ppm TCDD dioxin
Used by U.S. military in its Herbicidal Warfare program during
Vietnam War.
•
Million of gallons used 1962 - 1971 to remove unwanted plant life
otherwise provided cover for enemy forces during the Vietnam
Conflict
•
Veterans and to a greater extent the Vietnamese reported a variety of
health problems due to exposure that continues to this day
[graphic and disturbing images]
Movies:
http://www.pulitzercenter.org/openitem.cfm?id=426
Introduction
The Chemicals of Interest
Before……
After spraying Agent
Orange……
http://research.yale.edu/ysm/article.jsp?articleID=48
Baird and Caan, 2008
Introduction
The Chemicals of Interest
GE began using PCBs for a wide range
of industrial purposes in the late 1940s.
From 1947 to 1977, GE plants north of
Albany poured more than 1.3 million
pounds of PCBs into the upper Hudson.
200 miles is now designated NPL site
By the mid-1970s, a growing number of studies had found links to premature births
and developmental disorders, and had shown that PCBs caused cancer in lab
animals.
Today, the federal government classifies PCBs as probable human carcinogens.
They are also associated with reproductive problems, low birth weight, reduced
ability to fight infections and learning problems.
Source: http://www.nrdc.org/water/pollution/hhudson.asp
Health Effects
Effects in Utero
•
Exposure to low levels
results in impaired
intellectual development
NYT, September 12th 1998
Introduction
The Chemicals of Interest
•
•
•
•
•
Polyaromatic Hydrocarbons – PAH’s
Sources: oil tankers, refineries, offshore drilling, aluminum smelters,
creosote (railway ties)
Typically ng L-1
Larger PAH’s bioaccumulate
PAH’s, PCBs and Mirex implicated in devastation of beluga Whales in the
St. Lawrence River
Introduction
The Chemicals of Interest
3 main categories:
(b) Chemicals which cause damage to non-human biota but are not believed to harm
humans at current levels of exposure
e.g. Copper and zinc are essential trace elements for humans
Toxic to growing plants and there are regulations limiting their addition to soil in
materials such as sewage sludge
Introduction
The Chemicals of Interest
3 main categories:
(b) Chemicals which cause damage to non-human biota but are not believed to harm
humans at current levels of exposure
e.g. Endocrine disrupting chemicals
hormone mimics which disrupt reproduction and growth in wildlife
Introduction
The Chemicals of Interest
Baird and Caan, 2008
Introduction
The Chemicals of Interest
3 main categories:
(c) Chemicals not directly toxic to humans or other biota at current environmental
concentrations, but capable of causing environmental damage
e.g. CFCs
disrupt stratospheric ozone cycles
Turco, 2002
Introduction
The Chemicals of Interest
3 main categories:
(c) Chemicals not directly toxic to humans or other biota at current environmental
concentrations, but capable of causing environmental damage
e.g. Carbon Dioxide - the greenhouse effect
Introduction
The Chemicals of Interest
Introduction
The Chemicals of Interest
http://services.google.com/earth/kmz/changing_sea_level_n.kmz
Introduction
Units of Concentration
•
When describing environmental processes it is important to know how much of each
participating chemical is present
•
Confusing to the newcomer
Introduction
Units of Concentration
Soilds –
mass analyte/total mass of sample
•
mass per unit mass, also known as w/w
e.g. mg Pb / kg soil (mg/kg, mg kg-1)
•
Important with soils to note wet or dry weight due to moisture content
Introduction
Units of Concentration
Aquatic systems –
mass analyte/total mass of sample
•
mass per unit mass, ng kg-1 or μg kg-1
Or more commonly
mass analyte/total volume of sample
•
Mass per unit volume, mg L-1 (=ppm) or μg L-1 (=ppb) and ng L-1 (=ppt)
•
Unfortunately leads to confusion with units used in atmospheric chemistry which have
a different meaning (volume per unit volume v/v instead of w/v)
Introduction
Units of Concentration
ppmw vs. ppmv
e.g. 10 mg F per million mg of water
= 1 g F per million g of water
= 10 tons F per million tons water
= 10 mg F per million mg water
= 10 ppmw F (or ppm/w)
[since 1000,000 mg water = 1 kg water = 1 L water]
= 10 mg F per L water (10 mg/L or 10 mg L-1 F)
= 10 ppmv F (or ppm/v)
ppm = mg kg-1 = mg L-1
Introduction
Units of Concentration
•
ppm, ppb, etc. (assumes pollutant has same density as water, ρ = 1.00 g mL-1)
e.g. show that 1 mg/L = 1 ppm
 1 g pollutant
1 mg pollutant /L of H 2O
 1000 mg
1 mg/L = 1 ppm
1 μg/L = 1 ppb
1 ng/L = ppt
Conversions:
1 ppb = 1 ppm / 1000
1 ppt = 1 ppb /1000
  1 L H 2O  1 g pollutant
 =
 
 1 part per million
6
  1000 g H 2O  10 g H 2O
Question
Prove that 1 mg L-1 = 1 μg mL-1
1 mg x 1000 μg
mg
L
x 1000 mL
L
= 1 μg / mL
Question
Example 1: convert 0.100 M lead nitrate to ppm
First convert mol/L to g/L, then to mg/L (ppm)
M[Pb(NO3)2] = 331.2 g/mol
0.100 mols/L = 0.100 mols x (331.2 g/mol) / 1 L
= 33.1 g / L = 33.1 g/L x 1000 mg/g = 33100 ppm
Example 2: convert 0.01 g lead nitrate dissolved in 1L to ppb
First convert g/L to mg/L (ppm), then ppm to ppb
0.01 g/L x (1000 mg/g) = 10 mg/L = 10 ppm
10 ppm x 1000 ppb / ppm = 10,000 ppb
Introduction
Units of Concentration
Atmosphere –
Concentration units for gases
•
Mass per unit volume, μg m-3 (=ppm) or molecules cm-3
•
Not independent of temperature or pressure, volume of air will change, mass of pollutant won’t
change
e.g. air containing 1 μg m-3 SO2 at 0 °C will contain less than 1 μg m-3 SO2 if heated to 25 °C
Introduction
Units of Concentration
Atmosphere –
Mixing ratios
volume analyte/total volume of sample
•
Problem is overcome by expressing concentration of a trace gas as a volume-mixing ratio,
e.g. 1 cm3 SO2 dispersed in 1 m3 air = 1 ppmv
•
1 ppmv
•
Now if T or P changes effects both trace gas and air in which it is contained,
volume-mixing ratio does not change
= 1 molecule in 106 molecules
= 1 mol in 106 mols
= Partial pressure of 10-6 atm.
Introduction
Units of Concentration: Gases
•
Conversion (at normal temperature of 20 ºC and 1 atm.) from w/v to v/v:
concentration (ppmv) = concentration (mg m-3) x 24.0
Molar mass
Note: At STP of 273 K (0 C) the molar volume is 22.4
•
Similarly:
concentration (ppbv) = concentration (μg m-3) x 24.0
Molar mass
concentration (pptv) = concentration (ng m-3) x 24.0
Molar mass
Question
Convert 800 mg m-3 O3 (w/v) to ppm (v/v) without short-cut
M [O3] = 48 g mol-1
No. moles O3 in 1 m3 air = 800 mg / 48 g mol-1 = 800 x 10-3 g / 48 g mol-1
= 1.67 x 10-2 mol
Volume occupied by 1 mole at 20 °C and 1 atm (SATP)
= 24.0 L = 0.0240 m3
Volume O3 in 1 m3 air
= 1.67 x 10-2 mol x 0.0240 m3 mol-1
= 400 x 10-6 m3 = 400 ppmv
Question
Convert 800 mg m-3 O3 (w/v) to ppm (v/v) with short-cut
concentration (ppmv) = concentration (mg m-3) x 24.0
Molar mass
= 800 mg m-3 O3 x 24.0 = 800 mg m-3 O3 x 0.5 = 400 ppmv
48 g mol-1
Question
Express [O3] = 2.0 x 1012 molecules cm-3 as a volume mixing ratio
(ppbv)
[Convert to mg m-3 then use w/v to v/v conversion]
[O3] = 2 x 1012 molecules cm-3
= 3.3 x 10-12 mols cm-3
= 3.3 x 10-12 mols cm-3 x 48 g/mol = 1.6 x 10-10 g cm-3
= 1.6 x 10-7 mg cm-3 x (1 x 106 cm3 / m3)
= 0.16 mg m-3
= 0.16 mg m-3 x 24.0 / 48 g mol-1
= 0.080 ppmv = 0.080 x 1000 ppmv / ppbv = 80 ppbv
Question
Calculate the pressure of ozone in atm and in ppmv at the
tropopause (15 km, 217 K), given [O3] = 1.0 x 1012 molecules cm-3,
and p(total) = 0.12 atm
[O3] = 1.0 x 1012 molecules cm-3 x 1000 cm3/1 L x 1 mol/6.022 x 1023 molecules
= 1.7 x 10-9 mol L-1
pV = nRT,
p(O3) = (n/V) RT = 1.7 x 10-9 mol L-1 x 0.0821 L atm/mol K x 217 K = 3.0 x 10-8 atm
p(O3) ppmv = (3.0 x 10-8 atm / 0.12 atm ) x 106 ppmv = 0.25 ppmv
Introduction
Sources
•
•
Point – well-defined source
(e.g. end of a pipe, smokestack, drain)
Non-point - less well defined, cannot
be pinpointed
Arbitrary to some extent –
depends on spatial scale
e.g. air - one smoke stack (P)
meaningless to analysis of regional air
pollution, 100’s of stacks become NP
source
e.g. water - one house septic system
(P), on a regional scale may be
considered NP
Discharge from waste water
plant contaminates ground and
surface water
Source: USGS
Point and Non-point Sources
Smol, 2008
Introduction
Sources
Source
General Waste (representative)
Agricultural
Field and chemical waste, nutrients, pesticides/herbicides, petroleum fuels, feedlot waste, dairy waste
Chemical Industry
Metal products, metal sludges, nonmetal waste, electrical equipment waste, detergents/soaps/cleaners,
petroleum, metal plating, film processing, solvents, wastewaters, pesticides, smog precursors (NO X,
HC’s)
Mining Industry
Mine tailings, Mineral leachate (CN), acid mine drainage, coal, smelting waste, particulates
Energy Industry
Petroleum-based waste, solvents, gas and vapor emissions, coal tars, boiler waste, nuclear waste,
petroleum stored underground, smog and acid rain precursors ((NOX, HC’s)
Landfills
Chemicals
Incinerators
Incomplete combustion of feedstock, combustion by-prodcuts, metals, particulates
Medical Industry
Biohazards, pharmaceutical waste, solvents
Food Processing
Waste food products, rinsing waste, slaughterhouse waste
Domestic Waste
Detergents/cleaners, pesticides, fertilizers, compost, paints/solvents, gasoline
Municipal Governments
Water and wastewater treatment chemicals, sewage
Federal Givernemnt
Weapons-related waste, nuclear waste, petroleum-based waste
Dunnivant and Anders, 2006
Introduction
Sources
•
Basel Convention:
International treaty
regulating reporting,
disposal and transport of
hazardous waste
•
Designed to reduce
movement of waste
•
Nuclear waste not
included!
(Data from 2000,
metric tons)
http://www.basel.int/natreporting/index.html
Questions
1.
Correlate hazardous waste to a country’s development level
(economic status).
2.
Calculate the import/export ratio (if ratio > 1 the country is a net
importer). Are there any net importers?
3.
Why are Germany and Japan absent from the list?
4.
How does the US hazardous waste amount compare to the rest of
the world?
5.
Why is the US (40,821,482 tons in 2001) absent?
Questions
1.
Which state is the largest producer of hazardous waste?
2.
Which has the most hazardous waste generators?
3.
Conduct an internet search of a company from any state and
determine what are their waste chemicals.
Data
Large quantity
generator
http://www.epa.gov/epaoswer/hazwaste/data/biennialreport/
Data
Introduction
Summary
•
•
•
•
Pollution is the introduction of contaminants (chemicals, heat, light, noise)
into an environment that causes instability, disorder, harm or discomfort to
the physical systems or living organisms they are in
Chemicals
Units
Sources
References
•
•
•
Harrison, R.M. (2006) Introduction to Pollution Science. The Royal Society of
Chemistry, London.
Dunnivant, F.M. and Anders, E. (2006) A Basic Introduction to Pollutant Fate
and Transport: An Integrated Approach with Chemistry, Modeling, Risk
Assessment, and Environmental Legislation. Wiley-Interscience, New Jersey.
Smol, J.P. (2008) Pollution of Lakes and Rivers: A Paleoenvironmental
Perspective. Wiley-Blackwell.
Introduction
Harrison
• This chapter is available as a publisher’s Adobe PDF file here:
http://academics.rmu.edu/faculty/short/envs4450/textbooks/Harrison-IPS-Chp1.pdf