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
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
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.
(UI 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. college of Engineering
Source: Lucion Marine. 14 September 2011http://www.greenpassport.net/category/news/