Henry K.T. Wong

A Protocol for Minimizing Contamination in the Analysis of Trace Metals in Great Lakes Waters

The precautions and procedures aimed at minimizing contamination artifacts during the collection, filtration, and analysis of trace metals in fresh water are described. The techniques for proper decontamination of sample containers and labware and for field blanks are also presented. Samples are obtained using a portable clean laboratory and analyzed in a Class 100 pressurized room. Preliminary results obtained using the protocols described cast doubt on most of the published data on trace metal concentrations in the Great Lakes. The profiles of dissolved metal concentrations in the water column of Lake Ontario show very distinctive source-dependent features obfuscated in earlier studies by poor data quality.

Saturation of ecosystems with toxic metals in Sudbury basin, Ontario, Canada

Mining and resource recovery activities have not been kind to ecosystems in the Sudbury basin, Ontario. The combination of logging, smelting, fires and erosion resulted in an unusual anthropogenic ecosystem of denuded barren land with lifeless lakes, or a micro-desert. Since the 1970s, however, the concerted efforts made to reduce the emissions and rehabilitate parts of the degraded ecosystem have resulted in improvements in water quality, and recoveries in phytoplankton, zooplankton, zoobenthos and fish communities but have had little impact on toxic metal concentrations in many lakes. We show that most of the catchments in the Sudbury basin have become saturated with Cu and Ni, and some with Zn and Pb. It is estimated that mobilization of metals stored in soils and glacial overburden by surface runoff, groundwater drainage and wind re-working of tailings can sustain the high concentrations of Cu and Ni in many lakes for well over 1000 years. Strategies to immobilize the pollutant metals in the watershed rather than further emission controls may be required for dealing with high levels of toxic metals in surface waters of the saturated ecosystems.

Deposition and chemistry of pollutant metals in lakes around the smelters at Sudbury, Ontario.

(45) Seifert, W. K., see ref 14, p 21. (46) Pym, J. G.; Ray, J. E.; Smith, G. W.; Whitehead, E. V. Anal. Chem. 1975,47, 1617. (47) Datillung, M.; Albrecht, P. Mar. Pollut. Bull. 1976, 7,13. (48) Ensminger, A,; Joly, G.; Albrecht, P. Tetrahedron Lett. 1978,18, 1575. (49) Simoneit, B. R. T.; Kaplan, I. R. Mar. Enuiron. Res. 1980, 3, 113. (50) Seifert, W. K.; Moldowan, J. M.; Smith, G. W.; Whitehead, E. V. Nature (London) 1978,271, 436. (51) Eganhouse, R. P.; Simoneit, B. R. T.; Kaplan, I. R. Enuiron. Sci. Technol. 1981, 15, 315. (52) Simoneit, B. R. T.; Mazurek, M. A.; Cahill, T. A. J. Air Pollut. Control Assoc. 1980, 30, 387. (53) Crisp, P. T.; Brenner, S.; Venkatesan, M. I.; Ruth, E.; Kaplan, I. R. Geochim. Cosmochim. Acta 1979,43,1791. (54) Swisher, R. D. J. Am. Oil Chem. SOC. 1963,40, 648. (55) Lake, J. L.; Nonvood, C.; Dimock, C.; Bowen, R. Geochim.

Dispersion and toxicity of metals from abandoned gold mine tailings at Goldenville, Nova Scotia, Canada

Abstract As its name indicates, Goldenville was a famous gold mining area in Nova Scotia where large quantities of mercury were used in the gold recovery process. It is estimated that the 3 million tons of tailings left from the mining activities which lasted from 1860 to 1945 contain 470 kg of Cd, 37 300 kg of Pb, 6800 kg of Hg, 20 700 kg of As and 2600 kg of Tl. Analysis of metal contents of stream water, stream and lake sediments, tailings, and vegetation show that the tailings have been distributed over time across the stream basin to form a tailing field of approximately 2 km 2 . There is a continuous release of As, Hg, Pb, Tl and other metals from the tailing field, resulting in contamination of ecosystems downstream including the Gagogan Harbor of the Atlantic Ocean. Stream water and sediments of Lake Gagogan located downstream from the mine were found toxic to the benthic community. A loss of fish habitat was observed. Although the mines were closed over 50 years ago, sedimentary records of metal loadings into Lake Gagogan show that the release of metals from the tailings has not slowed down. Analysis of metal tolerant species in the area suggests that horsetails ( Equisetum rubiaceae and E . sylvaticum ) can be used in phytoremediation of sites contaminated with arsenic and mercury.

Particulate and dissolved trace metals in Lake Ontario

Abstract Particulate metal concentrations in the nearshore waters of Lake Ontario have been determined to be 690 ng l −1 for Cu; 40 ng l −1 for Cd; 180 ng l −1 for Ni; 1690 ng l −1 for Zn; 2100 ng l −1 for Mn; and 700 μg l −1 for Fe. These values are considerably higher than the particulate metal concentrations in the offshore waters: 130, 8, 34, 230, 110, 260 and 9000 ng l −1 for Cu, Cd, Ni, Zn, Pb, Mn and Fe respectively. In general, 50–80% of the Cu, 10–40% of the Ni, 20–60% of the Cd and >60% of the Pb in the lake water were bound to the suspended particulates. From the standing crop of the particulate metals and the estimated rates of their deposition on the lake bottom, the residence times of the particulate metals in the lake water column have been estimated to be about 0.5 yr. on the average. The suggestion is made that particulate organic matter may be an important vehicle for metal transport to the Lake Ontario sediments.

Atmospheric input of heavy metals chronicled in lake sediments of the Algonquin Provincial Park, Ontario, Canada

The flux of Pb, Zn, Cu, Ni and Cd into ten remote lakes in the Algonquin Provincial Park of Ontario has been determined. Deviation from constant sedimentation rates in recent sediments depicted in the 210Pb profiles can be related to human activities within the last 100 years. Sedimentation rates in these softwater lakes vary from 0.5 mm yr.−1 (62 g m−2 yr.−1) to 2.9 mm yr.−1 (190 g mm−2 yr.−1). The corresponding present-day metal flux rates for Ni, Cu, Pb, Zn and Cd are 0.6–8.4, 0.7–9.4, 3.7–43.5, 5.0–50.3 and 0.07–0.74 mg m−2 yr.−1, respectively. There is an overall 2-fold enrichment for Ni, Cu, Zn and Cd in surficial sediments together with a 25-fold increase for Pb. The gyttja contain 25–50% organic matter with (organic C)/(organic N) ratios which strongly suggest high influx of allochthonous plant debris.

Historical Records of Metal Pollution in Sediments of Toronto and Hamilton Harbours

The sediments of Hamilton and Toronto Harbours contain some of the oldest records of metal pollution in the Great Lakes basin. The fluxes of Cd, Cr, Cu, Ni, Pb, Zn, Fe, and Mn into the two harbours have been estimated from the analyses of core samples dated by the Pb-210 technique. The contrasting metal levels in the two harbour sediments are viewed in relation to the differences in the disposal strategies of the dredged spoils and the sources of metal pollution in the harbours. The Zn and Fe concentrations of 5 to 8 mg g−1 and 10 to 13 % dry wt. in Hamilton Harbour sediments, which are among the highest recorded in any harbour, can be related to effluent discharges from the large local iron and steel plants. An inventory of the sources and sinks of pollutant metals in Hamilton Bay shows a substantive export of the metals to Lake Ontario.

Trace metals in fluid-preserved museum fish specimens

This paper describes the effects of preservation on the trace metal levels in the larvae of four lamprey species, Petromyzon marinus, Ichthyomyzon fossor, I. unicuspis and Lampetra appendix, collected between 1946 and 1951 from three tributaries of the St. Lawrence River Basin, Quebec. Contrary to most other studies on the subject, this study rejects the usefulness of using fluid-preserved museum fish specimens in retrospective monitoring of trace metal levels in the aquatic environment because the many sources of contamination cannot be accurately measured.

Dynamics of particulate trace metals in the lakes of Kejimkujik National Park, Nova Scotia, Canada

Abstract A study of the settling characteristics and the accumulation rates in sediments suggests that a large fraction of the organic carbon and trace metals in the suspended particulates in Kejimkujik Lake has been imported from the lakes watershed. The mean seston settling velocity has been estimated to be about 0.1 m day −1 in Kijimkujik Lake and 1–2 m day −1 in Mountain Lake. For the particulate organic carbon, it has been estimated that the mean flux through the water column is 167 mg m −2 day −1 , the mineralization rate is 16 mg m −2 day −1 , and the accumulation rate in sediments is 9 mg m −2 day −1 . It is shown that the movement of the recalcitrant organic material is the key feature controlling the fate and behavior of trace metals in these lakes.

Aluminum species in porewaters of Kejimkujik and Mountain Lakes, Nova Scotia

Sediment porewaters were recovered by the membrane dialysis technique from Kejimkujik Lake and Mountain Lake in Nova Scotia and analyzed for pH, dissolved organic carbon (DOC), total (acid soluble) aluminum, total reactive monomeric aluminum (TRM-Al), organic monomeric aluminum and inorganic monomeric aluminum. The results show that in the colored lake water (Kejimkujik), close to 100% of the TRM-Al fraction is bound to organic matter and that 10 to 60% of the total-Al is in the monomeric form. In the clearwater lake (Mountain), 50 to 65% of TRM-Al fraction is associated with organic matter and less than 4 to 5% of the Total-Al is in the monomeric form. The concentrations of reactive monomeric species in organic-rich porewaters decrease with time of storage due to the precipitation of organo-Al compounds. Model calculations using the porewater profiles for Al suggest that the sediment can be an important source of dissolved Al to the overlying water.