Persistent organic pollutants in remote freshwater ecosystems

Abstract

Persistent organic pollutants (POPs), including organochlorine compounds (OCs) and polycyclic aromatic hydrocarbons (PAHs) were measured in two European remote mountain lakes situated in the Pyrenees (Lake Redon) and the Tatra Mountains (Ladove). Both dissolved and particulate water phases were analyzed at different water column depths.OCs already banned in most European countries showed similar concentrations in the two lakes, e.g. 6.7-8.5 pg L -1 for HCB, 8.0-12 pg L -1 for DDTs, and 60-64 pg L -1 for PCBs (sum of seven individual congeners), being in general lower than those reported in other remote aquatic systems. On the contrary, compounds of present use or currently emitted to the atmosphere exhibited significant concentration differences between sites. Thus, the higher levels of HCHs (1000-2630 pg L -1 ) and endosulfans (780-1610 pg L -1 ) in Lake Redon than in Ladove are in agreement with an impact of Aquatic Sciences agricultural activities in the former. In contrast, the higher PAH concentrations in Ladove, 12 ± 1 ng L -1 (mean ± standard deviation), than in Lake Redon, 0.77-1.6 ng L -1 evidence higher deposition of combustion residues in the Tatras.POP concentration decreases with depth were observed for the compounds present in the dissolved phase such as endosulfan, HCB, and the low molecular weight PCBs and PAH. The vertical differences were higher in Lake Redon, probably due to its deeper basin. These gradients are consistent with the incorporation of these compounds into the lakes by air-water exchange through the gas-dissolved phase.In contrast, PCBs or PAH associated to the suspended particulate material (those of higher molecular weight) showed uniform concentrations throughout the water column, which may reflect high efficiency in the vertical transport of the compounds associated to this phase.

Evaluation of the Egg Bank of Two Small Himalayan Lakes

“…If our interpretation is true, we might be very concerned about the future of biodiversity of these lakes, so beautiful, so fragile. Given the low connections of these lakes with other aquatic environments, and their remoteness, our results highlight their high vulnerability to loss of biodiversity and of taxa which are unique and precious, super-exposed to impact of climate change and long distance transport of pollutants [109][110][111].…”

Supplementary material to "Atmospheric processes of persistent organic pollutants over a remote lake of the central Tibetan Plateau: Implications for regional cycling"

“…We can derive the unknown diffusivity of target compounds in the present study by using the diffusivity of a reference substance, such as D a (H 2 O) and D w (CO 2 ) according to the following equation (Schwarzenbach et al, 2003): Part 2. Concentrations of dissolved phase PAHs (pg L -1 ) in the water from different sites of the lake (S1-S15): o,p'-DDE p,p'-DDE o,p'-DDT p,p'- (Zhang et al, 2003) Co Ngoin, TP 2002 550 810 190 (Zhang et al, 2003) Taihu Lake, China 2004-2005 1887±1372 1773±944 484±373 53±113 77±91 135±287 12±4 (Qiu et al, 2008) Chaohu Lake, China 2010-2011 460±460 900±480 280±310 170±70 1640±1820 20±40 140±390 220±220 (Ouyang et al, 2013) European mountain lake 2000 68±35 139±89 8.5±3.2 12±3 (Fernandez et al, 2005) North Pacific 2010 101.6 27.7 17.9 2.8 (Cai et al, 2012) Indian Ocean 2011 3.2±0.8 5.4±2.2 2.2±1.3 48±120 37±85 330±840 1600±4000 (Huang et al, 2013) Ross Sea, Antarctic 2003-2004 1.4±0.9 2.9±2.2 (Cincinelli et al, 2009) North Atlantic and Arctic 2004…”

“…S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 S14 S15 2012-2014 2006-2008 2006-2007 2008-2011 2002 2000 2001-2003 2007-2010 2000-2003 (Guzzella et al, 2011) Lake Redo, Pyrenees 2000 0.27 ± 0.19 0.41 ± 0.13 (Vilanova et al, 2001) Lake Gossenkolle, Alps 2000 0.35 ± 0.19 0.57 ± 0.34 (Vilanova et al, 2001) Lake Ladove, High Tatras 2000 3.4 ± 0.4 8.5 ± 0.7 (Fernandez et al, 2005) Lake Ontario 2011-2012 5.5 ± 3.2 (Venier et al, 2014) Lake Erie 2011-2012 4.8 ± 1.4 (Venier et al, 2014) Lake Superior 2011-2012 1.1 ± 0.5 (Venier et al, 2014) Atlantic Ocean 2005 (0.058-1.07) (Nizzetto et al, 2008) North Pacific and Arctic 2010 (0.014-0.76) (Ma et al, 2013) Gerlache Inlet Sea, Antarctica 2001 2.4 (2.1-2.9) 3.6 (2.8-4.7) (Stortini et al, 2009)…”

Anthropogenic influences on the environmental status of remote mountain lakes

“…POPs, which are toxic, volatile and chemically stable, are distributed widely by long-distance atmospheric transport, and can be easily detected in high mountain lakes. Fernández et al (2005) describe a comprehensive comparative analysis of POPs (including hexachlorocyclohexanes, endosulfans, hexachlorobenzene, DDTs, polychlorinated biphenyls and polycyclic aromatic hydrocarbons) in two lakes in the Pyrenees and the Tatras. They discover that those POPs that are no longer being actively deposited because they are now banned in most of Europe show similar, relatively low concentrations in both lakes, whereas POPs that are still in use, and therefore currently being emitted, show significant differences in concentration between the lakes.…”