Occurrence of C₁₀−C₁₃ Polychlorinated n-Alkanes in Canadian Midlatitude and Arctic Lake Sediments

Abstract

Sediment cores from six lakes in Canada ranging from 49°N to 81°N were analyzed for C10−C13 polychlorinated n-alkanes (PCAs) with the intent of (i) examining the depositional trends with increasing latitude, (ii) studying the historical profiles and fluxes of PCAs in dated sediment slices, and (iii) investigating possible in situ degradation. Sediment slices were dated using 210Pb and 137Cs, and extracts were analyzed for PCA concentrations by high resolution gas chromatography electron capture negative ion high resolution mass spectrometry (HRGC-ECNI/HRMS) in the selected ion monitoring (SIM) mode. Concentrations of total PCAs in surface sediments declined significantly from 135 ng/g (dry weight (dw)) in sediments from the southern basin of Lake Winnipeg (50°N/96°W, Manitoba) to 4.52 ng/g in Hazen Lake (81°N/71°W, high Arctic); corresponding surficial fluxes were 147 and 0.9 μg/m2 yr, respectively. The high flux of PCAs to the south Lake Winnipeg basin suggests local contamination. This was confirmed by analyzing water collected from the Red River, a river that discharges into the southern basin of Lake Winnipeg, in which elevated levels of PCAs were detected (0.02−0.05 μg/L). The surficial flux of PCAs to Fox Lake (61°N/135°W), a subarctic lake in the Yukon, was also high, 34 μg/m2 yr. Much lower fluxes were found in Lake Nipigon (49°N/89°W, N. Ontario), 3 μg/m2 yr, the northern basin of Lake Winnipeg (52°N/98°W, Manitoba), 4 μg/m2 yr, and to Ya Ya Lake (69°N/134°W, Arctic) 0.45 μg/m2 yr. The remote locations of Hazen and Ya Ya Lakes and the low levels of PCAs observed in their corresponding sediment slices are consistent with long-range atmospheric transport. The profiles of PCAs in the midcontinental lakes showed maxima in slices dated from the early 1980s to the 1990s while that of ΣDDT showed a maxima in the 1960s. The presence of PCAs in surface sediments over a wide geographic area, including the Canadian Arctic, suggests that these compounds, which are components of commercial short chain chlorinated paraffins, are regionally and globally distributed by long-range atmospheric transport.

Occurrence, bioaccumulation and long-range transport of short-chain chlorinated paraffins on the Fildes Peninsula at King George Island, Antarctica

“…The detection of SCCPs in the polar regions would provide direct evidence for their long-range transport, but SCCPs have been observed in polar regions in only a few studies. The concentrations of SCCPs were studied in the biota and sediment samples from Arctic and sub-Arctic environments (Reth et al, 2006;Strid et al, 2013;Tomy et al, 2000;Tomy et al, 1999). For Antarctica, the only data for SCCPs are from the air samples collected on the Fildes Peninsula (Ma et al, 2014c).…”

Temporal Trends and Pattern Changes of Short- and Medium-Chain Chlorinated Paraffins in Marine Mammals from the South China Sea over the Past Decade

“…1 Currently available data indicate that CPs, especially SCCPs, are persistent in the environment, 2 are toxic to aquatic organisms and carcinogenic to mammals, 3−5 have the potential to bioaccumulate and/or biomagnify in fresh and marine food webs, 6−8 and can be prone to long-range atmospheric transport due to their semivolatile properties. 9,10 A global regulation/ban on SCCPs as a persistent organic pollutant (POP) candidate is being reviewed under the Stockholm Convention, 11 but the current information is insufficient to adequately assess the chemicals.…”

Behavior, Fate, and Mass Loading of Short Chain Chlorinated Paraffins in an Advanced Municipal Sewage Treatment Plant

“…3 The presence of CPs in the environment has been ascertained in various environmental matrices (air, water, soil, sediment, and biota) worldwide. 4−9 Compared to other two groups of CP mixtures, SCCPs have received growing global attention in recent years for their long-range transport, 10,11 persistence in the environment, 12 bioaccumulation in food webs, 13 and potential toxicity to aquatic organisms. 14,15 Currently, SCCPs are being reviewed by Stockholm Convention's POP Review Committee (POPRC) to evaluate whether this substance meet the criteria on persistent organic pollutants (POPs).…”