Polychlorinated Biphenyls in Glaciers. 1. Deposition History from an Alpine Ice Core

Abstract

We present a highly time-resolved historical record of polychlorinated biphenyls (PCBs) from an Alpine ice core (Fiescherhorn glacier, Switzerland). Introduced in the 1940s, PCBs were widely used industrial chemicals. Because of their persistence they are still found in the environment, long after their production phase-out. The Fiescherhorn ice core record covers the entire time period of industrial use of PCBs, that is, 1940-2002. The total concentration of six PCBs varies from 0.5 to 5 ng L(-1) and reveals a temporal trend, with an 8-fold increase from the early 1940s to the peak value in the 1970s. The level in 2002 is comparable to the concentration in the 1940s, when PCBs were introduced into the market. The time trend of PCBs associated with the particulate fraction closely follows the trend found in the dissolved fraction, but the absolute values are a factor of 10 lower. In addition to changing emissions, fluctuations in the PCB record were explained by variabilty in convective transport and postdepositional processes such as surface melting. Concentrations of PCBs are in agreement with data from seasonal snow samples in the Alps, but are a factor of 100 higher than concentrations measured in the Arctic. Contrasting time trends and congener patterns between the Alpine and Arctic region indicate the importance of atmospheric transport and postdepositional effects.

Baltic Sea sediment records: Unlikely near-future declines in PCBs and HCB

“…The global usage of PCBs culminated in the mid 1970's (Breivik et al, 2007), and since then concentrations in the environment have decreased dramatically (Schuster et al, 2010;Airaksinen et al, 2014;Pavlova et al, 2014;Rasmussen et al, 2014). Currently, the PCB decline in the environment is levelling off (Hansson et al, 2006;Thevenon et al, 2013;Airaksinen et al, 2014), which for the Baltic Sea also would imply stabilising PCB concentrations in biota.…”

Organochlorine Pollutants within a Polythermal Glacier in the Interior Eastern Alaska Range

“…[6][7][8][9] The highest OCP concentrations measured englacially, to date, were found in ice cores from the Italian Alps in 2001 (20 ng/L), [5] containing chemicals α-and ϒ-HCH. While subsequent OCP studies in the Swiss Alps found concentrations of the same magnitude (PCB-12.5 ng/L), [6] all studies from the Arctic, including Svalbard (PCB-1.5 ng/L) [7] and Canada (DDT-2.5 ng/L) [9,10] have found lower OCP concentrations. The atmospheric range potential of each chemical is determined in part by distance from source, air mass transport, weight and volatility, with some pesticides able to redeposit multiple times.…”

“…Particle sorbtion within Jarvis' sediment-rich ice layers may increase OCP loss during englacial and supraglacial melt events. [52][53][54] Ice core concentrations indicate that ΣDDT is the greatest contributor to OCP concentrations within Jarvis Glacier. ΣDDT deposition may be a result of use prior to the Stockholm Convention ban, however, continuing DDT use in Asia to combat malaria may explain why comparatively elevated rates occur in samples proximal to the surface.…”

“…The atmospheric range potential of each chemical is determined in part by distance from source, air mass transport, weight and volatility, with some pesticides able to redeposit multiple times. [6,7,[10][11][12][13][14] ΣHCH has the greatest atmospheric range of all OCPs, due in part to its high volatility and low reactivity, which increases the probability of Arctic deposition. [15][16][17][18][19] Based upon this previous work, we hypothesized that it would be possible to identify an OCP signal within glaciers of the Interior Alaskan Arctic, where no OCP glacial sampling studies have been conducted.…”

Pd-loaded magnetic mesoporous nanocomposites: A magnetically recoverable catalyst with effective enrichment and high activity for DDT and DDE removal under mild conditions

“…Even almost thirty years after they were banned in China and other numerous countries [1], high concentrations of organochlorine compounds still exist in soil, sediment, water and air [2][3][4]. Their persistence, toxicity and bioaccumulation greatly affect the environmental qualities, and animal and human health [5].…”