5.2 Pollution Detection

1. "The word sustainable has been reduced to being the
Praise, Jesus!
of the eco-earnest. It's a word where corporate marketers, with their
mediated up-swell of green sentiment, mesh perfectly with the
relentless denial of the privileged.
It's a word I can barely stand to use because it's been so
exsanguinated by the morally limp, the personally smug, the
cheerleaders for the technotopic, consumer kingdom come.
To doubt the vague promise now firmly embedded in the word - that
we can have our cars, our corporations, our consumption and our
planet, too - is both treason and heresy
to the emotional well-being of most progressives.
But here's the question: Do we want to feel better or do we want to be
effective?
Are we sentimentalists or are we warriors?"
-- Lierre Keith

2. 5.2 Pollution
Detection and Management
J. Voytilla

3. Pollution Detection
 Pollution can be measured both DIRECTLY and
INDIRECTLY
1. Direct methods involve taking measurements directly
from air, soil, or water.
- e.g. acidity of rainwater, amount of a gas present, amount
of nitrates and phosphates, etc
2. Indirect methods involve measuring changes in biotic
and abiotic factors which occur as a result of pollutants.
- e.g. measuring O2 content of water, presence/absence of
indicator species

4. Research!
 Please find 2 DIRECT methods of monitoring
pollution for each of
a) Water
b) Air
c) Soil

5. Indirect Methods: B.O.D.
 The BIOCHEMICAL OXYGEN DEMAND is a
measure of dissolved O2 required to break down the
organic material in a given volume of water through
aerobic biological activity.
Broken down by whom?
 The BOD can thus be used as an indirect method of
estimating pollution levels in water, and in fact it is
considered a standard test to detect the polluting
capacity of effluent.

6. BOD
 How does it work?
- The greater the quantity of organic pollutant, the greater
the amount of O2 consuming microbes
- More microbes means that more O2 is used
- Thus the more organic pollutant present, the higher the
BOD
The BOD test measures the mass (in mg) of dissolved O2
CONSUMED per litre of water when a water sample is
incubated in a dark chamber at 20 C for five days.

7. Examples of BOD Values
Source BOD (mg/L)
Unpolluted river < 5
Treated sewage 20 – 60
Raw domestic sewage 350
Cattle slurry 10,000
Paper pulp mill 25,000

8. Calculate BOD
Volume O2 BOD Probable
Location
120 L 48 g
3000 L 45 kg
23000 L 184000 mg

9. Indirect Methods: Biotic
Indicators
 Indicator species are those that demonstrate the
relative health of an area or ecosystem by their
presence or absence or abundance or their scarcity.
 These species are particularly vulnerable or
sensitive to changes in the environment.
 A Biotic Index is a scale or range (1-10) that
provides a measure of the quality of an ecosystem
by the presence and abundance of the species living
in it.

10. Indicator Species
 Thus, if an ecosystem polluted a particular indicator
species could be
a) Absent
b) Reduced in number
c) Present
d) Present in abundance
 This is due to the species’ particular tolerance for a
pollutant: some dig it, some can’t abide it

11. Research
 Research 10 indicator species that are used to
monitor pollution / ecosystem health.
 Include whether its the
presence/absence/abundance/index of the species
that is used.
 Include what problem each species is used to
indicate.