Using Cs-137 to help trace the transport and fate of PCBs in the Hudson River

The purpose of this laboratory is to see whether the limited set of PCB data provided from 28 sediment cores along the length of the Hudson River and its major tributaries allows one to understand where the major sources of PCBs to the Hudson River are located, and also to evaluate industry claims as to prior release. Also provided will be the results of a mass balance for how much Cs-137 is stored in Hudson River sediments based on 240 cores collected along much of the length of the river.


PART I:

Download the data set from the web or or copy it from the disk in class.

Get familiar with the data set
This is a relatively large data set. You will need to split your screens to be able to move around in it and still know what columns and rows represent.

The EPA sample code #'s are the following:
HR-007-0204
HR- high resolution core
007- the 7th core collected during the high resolution effort
0204- the 2 to 4 cm depth section of the core.

Core HR-009 was collected in a core liner with an inner diameter of 9.50 cm.
All other cores were collected in core liners with inner diameters of 5.70 cm.

River mile refers to the approximate # of miles north of the south tip of Manhattan measured along the axis of the river

Some measurements required the samples to be taken while the sediments were still wet. These subsamples were taken with open ended glass syringes of two different diameters dependent upon which measurements were being made. Estimates can therefore be made on the amount of material removed and corrected dry wts can be calculated.

Notice that each parameter has it's own sample identifier since some depth sections were composited before the measurements were made. You will have to take this into account when making some of the calculations.

There are four cores collected from important tributaries to the Hudson River. You should think of how to treat these data separately in your graphs.

There are two quantifications of the gas chromatograms for Total-PCBs. Usually they result in the same estimate for total-PCBs. You should average the results for use in your calculations You may also want to use mg/kg as the units rather than µg/kg.

Familiarize yourself with the location of the cores based on the attached maps.