Assignment:
Q1. Provide three reasons for children’s high susceptibility to lead (Pb) toxicity, when compared with adults.
Q2. Current reference dose for oral exposure to methylmercury is 0.1 ug/kg of body weight (U.S. EPA, February 2004). For a woman of 60 Kg, the reference dose is equivalent to ingesting 6.0 ug per day. Question: Based on the median concentrations of Hg in the aquatic species in Table H (see below), assuming 90% of the Hg is methylmercury, which of the items the woman can consume in the amount of 0.25 kg per day to keep the exposure below 6.0 ug/day?
Q3. Is trimming off skin and fat of methylmercury contaminated fish an effective method to decrease exposure? Please explain your answer.
Q4. Identify the susceptible populations of arsenic toxicity.
Q5. Identify the susceptible populations of cadmium toxicity.
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Table H. Concentrations of Hg (mg/kg) in UK Imported Fish and Shellfish and UK-Farmed Fish and Their Products (Knowles et al., 2003)
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Product type
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Levels of Hg (mg/kg)*
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n
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Minimum
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Maximum
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Median
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Mean
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Species limit (mg/kg)
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Fish
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halibut
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8
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0.038
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0.617
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0.288
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0.290
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1.0
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hoki
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2
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0.065
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0.307
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0.186
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0.186
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0.5
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monkfish
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2
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0.096
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0.300
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0.198
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0.198
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1.0
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orange roughy
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6
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0.527
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0.647
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0.602
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0.595
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1.0
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pollack
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4
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0.007
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0.020
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0.010
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0.012
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0.5
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salmon
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14
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0.029
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0.079
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0.047
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0.050
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0.5
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sea bass
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4
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0.030
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0.094
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0.068
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0.065
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1.0
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sea bream
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4
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0.051
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0.056
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0.053
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0.053
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0.5
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shark
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5
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1.006
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2.200
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1.402
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1.521
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1.0
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billfish
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20
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0.153
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2.706
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1.260
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1.340
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1.0
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trout
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14
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0.014
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0.103
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0.054
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0.060
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0.5
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tuna
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20
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0.141
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1.500
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0.310
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0.401
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1.0
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Shellfish
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exotic prawns*
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14
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0.006
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0.047
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0.021
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0.025
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0.5
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lobster
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4
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0.009
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0.231
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0.030
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0.075
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0.5
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mussels
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4
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0.017
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0.041
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0.031
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0.030
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0.5
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other**
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9
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0.003
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0.186
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0.013
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0.038
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0.5
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prawns
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14
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0.013
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0.249
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0.028
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0.048
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0.5
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squid
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9
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0.003
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0.036
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0.008
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0.011
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0.5
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* 'Exotic prawns' included samples of: tiger prawns, black tiger prawns, king prawns, giant tiger prawns, large king prawns and fantail prawns.
**'other' included samples of: scallops, snow crab, vongoles. Also included in this category was octopus.
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Provide complete and step by step solution for the question and show calculations and use formulas.