High levels of polychlorinated biphenyls
(PCBs) were found by University of Iowa researchers in the deep sediment blow the Indiana Harbour
and Ship Canal (IHSC) in the area of southern Lake
Michigan . This is a large cause for concern because PCBs are a
highly hazardous waste that has been shown to cause cancer among other serious
illnesses.
PCBs were originally commonly used as coolants in
transformers and electric motors. It has now been classed as a persistent
organic pollutant and production of PCBs is now banned in the UK .
The hazardous material can be exposed to the human
body through a number of mediums, including through -
Ø
contact with
the skin,
Ø
contaminating
the food and drink we consume, or
Ø
the air we
breathe.
For this reason, PCBs when found must be taken with
extreme care. The study by UI was the second study to the area, the first of
which found PCBs to be present from the sediment floor to the water and air.
This second study, whereby researchers drilled two excavations into the floor
of the canal, found the concentration of the PCBs to be much greater.
The presence
of PCBs on this site is of even greater concern due to the fact that the site
is due to be dredged in early 2012 by the U.S. Army Corps of Engineers to
restore adequate navigational depth to maintain the canals use for large ship
traffic.
Hornbuckle and Martinez
(UI college of Engineering professors and co-authors of
the study) recommend that the dredging strategy should now be adapted to
consider the presence, and large concentration levels, of PCBs in order to
minimise the potential exposure to PCBs: “it’s not the act of dredging that is
the problem. The problem is when you leave contaminated chemicals at the
surface that continue to be released forever”. However, researchers have
acknowledged that the engineers may not dredge deep enough to expose the PCBs.
The IHSC will need to decide whether they wish to go ahead with works as
planned with the added risk of exposure, or change the plans and potentially
disrupt the productivity of the harbour, but ensure that no PCB exposure is
possible in the future.
Source: Lucion Marine. 14 September 2011
http://www.greenpassport.net/category/news/
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