A Modeling Strategy for Planning the Virtual Elimination of Persistent Toxic Chemicals from the Great Lakes: An Illustration of Four Contaminants in Lake Ontario

Abstract A systematic seven-step process is proposed as a strategy for planning “virtual elimination” of persistent toxic contaminants in the Great Lakes. The strategy involves (i) estimating loadings, (ii) gathering prevailing concentration data, (iii) obtaining physical-chemical property data for the chemicals of interest, (iv) obtaining data concerning conditions in the lake, (v) applying a relatively simple steady-state mass balance model incorporating an appropriate treatment of variability and uncertainty to reconcile the range of estimated concentrations with the range of monitoring data, (vi) identifying reasonable targets for loading reductions, and finally (vii) applying the model in dynamic form to estimate how future concentrations will respond to suggested loading reductions thus providing a set of targets for virtual elimination. The uncertainties in these estimates are quantified to convey an impression of their perceived accuracy. The strategy is illustrated for four contaminants (polychlorinated biphenyls, benzo(b)fluoranthene, arsenic, and lead) in Lake Ontario.

[1]  Frank A. P. C. Gobas,et al.  A Rate Constant Model of Chemical Dynamics in a Lake Ecosystem: PCBs in Lake Ontario , 1994 .

[2]  E. Voldner,et al.  Production, Usage and Atmospheric Emissions of 14 Priority Toxic Chemicals: Appendix 2 to the Proceedings of the Workshop on Great Lakes Atmospheric Deposition , 1986 .

[3]  D. Mackay.  Modeling the Long-Term Behavior of an Organic Contaminant in a Large Lake: Application to PCBs in Lake Ontario , 1989 .

[4]  C. W. Sweet,et al.  Atmospheric deposition of toxic chemicals to the Great Lakes: A review of data through 1994 , 1996 .

[5]  James A. Barres,et al.  Trace Element Concentrations in Near-Surface Waters of the Great Lakes and Methods of Collection, Storage, and Analysis , 1988 .

[6]  A. Mudroch,et al.  Geochemical Composition of the Nepheloid Layer in Lake Ontario , 1992 .

[7]  C. W. Sweet,et al.  Seasonal variations in air-water exchange of polychlorinated biphenyls in lake superior. , 1994, Environmental science & technology.

[8]  W. Shiu,et al.  Illustrated handbook of physical-chemical properties and environmental fate for organic chemicals. Volume 5: pesticide chemicals. , 1992 .

[9]  D. Persaud,et al.  Guidelines for the protection and management of aquatic sediment quality in Ontario , 1993 .

[10]  W. Shiu,et al.  Polynuclear aromatic hydrocarbons, polychlorinated dioxins, and dibenzofurans , 1992 .

[11]  W. Shiu,et al.  Monoaromatic hydrocarbons, chlorobenzenes and PCBs , 1992 .

[12]  Ron Shimizu,et al.  THE GREAT LAKES BINATIONAL TOXICS STRATEGY: CANADA-UNITED STATES STRATEGY FOR THE VIRTUAL ELIMINATION OF PERSISTENT TOXIC SUBSTANCES , 1998 .