METALS IN THE SEDIMENTS OF THE NORTH RIVER, SALEM, MA

The North River and its tributaries serve as the largest source of fresh water entering Salem Sound. The river is largely contained within the coastal Massachusetts towns of Salem and Peabody, approximately 15 miles north of Boston. The river and its tributaries are heavily used as a recreational area by the local population. Waste water from tanneries and other industries have been known to be emptied into the North River and its tributaries for over 200 years. Many of the waste products contained toxic metals such as As, Cd and Cr. To assess the distribution of heavy metals within river sediments of the North River, samples were analyzed with a portable workstation x-ray fluorescent analyzer. Samples were collected along a length of the North River channel in Peabody MA, next to Lesley’s retreat park at the intersection between Commercial Street and Rt 114 and also a small park just north of this area on Franklin Street. The full range of metals of interest in this study include As, Cd, Cr, Cu, Pb, Hg, Ni, Ag, and Zn. Results of this study indicate concentrations of some of the metals in excess of values known to cause adverse effects to 10-50 percent of the biological population within the sediments. In particular, Cr, Hg and Pb are consistently at concentrations that fall within the “probable effects range” while Cu, Zn and As consistently fall within the “possible effects range”. The specifications of the portable x-ray fluorescent spectrometer used in this study, the data collection techniques, results of the sediment analysis, and the distribution of heavy metals in the river sediments will be presented. In general, portable x-ray fluorescence is an efficient way to screen areas that may contain these metals.