A main focus of my environmental chemistry research is the interpretation of dated sediments as indicators of major contaminant sources. Many persistent contaminants of the industrial age ultimately reside within the sediments of aquatic systems. With a few well-chosen sediment samples, it is often possible to say a great deal about contaminant sources, transport, and fate in a complex environment. Recent work has focused on contaminants in New York Harbor, the Hudson River, and urban and rural lakes and reservoirs in the Hudson Basin. [more...]

Interpretation of the sediment record depends on an accurate determination of an age vs. depth relationship within the sediment column, most often achieved by the use of radionuclide indicators such as 137Cs, 210Pb, and 7Be. Many sediment cores have radionuclide profiles that suggest the influence of processes which complicate age assignment. Specifically, radionuclide diffusion, post-depositional mixing and delayed input from drainage basin erosion can all — independently or in combination — influence the distribution of particle-associated radionuclides and contaminants within a core. Resolving these effects is a necessary step in the estimation of radionuclide delivery fluxes. [more...]

While sediment cores provide an "integrated" record of contaminant flux over time, the importance of short-duration transport events is often obscured in the sediment record. In the Hudson River and tributaries, these short-duration events can be investigated using acoustic backscatter measurements. [more...]

I was part of the development team for the World Trade Center Environmental Contaminant Database (WTCECD), a publicly-available repository of air monitoring data in the New York/New Jersey area. The WTCECD includes over three decades of ambient air quality data from fixed-site monitoring stations in New York City and the state of New Jersey. [more...]