ASSIGNMENT 1
BIOMAGNIFICATION, HABER’S RULE, HAZARD ASSESSMENT
AND PROBIT ANALYSIS
ENVR/BOTN/ZOOL/AGRI 2180 and 2190 Introductory Toxicology
This assignment is worth 15% of your final grade and is due at the
start
of class on
Tuesday, February 20
th
, 2007.
The total marks for this assignment are 50.
It is advised to
do any calculations etc., and even the entire answer, in rough before filling in the answer
sheet.
Marks will be deducted for poor grammar, syntax and spelling as well as answers
that are unclear or disorganized.
Use
only
the space provided to respond and attached
require graphs to the answer sheet with a staple.
The graphs must be done using graphing
software, such as Excel, SigmaPlot or other available software.
Name: __________________________________
Student Number: __________________________
HABER’S RULE
1)
Using Haber’s Rule on the data set in Table 1, plot the relationship and report the
equation between time and the concentration required to cause a specific effect as a linear
function.
(6 marks)
Remember to log transform the values!
2)
You estimate the concentration of carbamate required to kill 50% of the
Daphnia
magna
after 48 hours of exposure to be
_2.08 or 2.05 or 2.1 ug/L_
.
(1 mark.)
Table 1:
Acute toxicity data for
Daphnia magna
exposed to the carbamate insecticide
carbofuran.
Time
LC
50
(μg/L)
12
8.4
24
4.2
72
1.4
96
0.98
168
0.61
BIOMAGNIFICATION
11)
You are concerned about possible biomagnification of a perfluorinated surfactant,
in this case, PFOS (perfluorooctance sulfonate), in arctic ecosystems.
PFOS was one of
the key ingredients in Scotchgard, formerly produced by 3M.
To see if there are any
concerns, you have sampled various zooplankton, fish, birds, marine and terrestrial
mammals for PFOS in their tissue (see Table 2).
The next step is to examine the trends in
the data and plot the relationship between concentration versus trophic level.
Before you
do this, you need to determine the trophic level of each organism and normalize the tissue
1

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