Spatial and temporal trends in PCBs in sediment along the lower Rhône River, France

Abstract

Despite increasingly strict control of polychlorinated biphenyl (PCB) releases in France since the mid-1970s, PCB contamination of fish recently has emerged as a major concern in the lower Rhône River basin. We measured PCB concentrations in Rhône sediment to evaluate the effects of PCB releases from major urban and industrial areas, sediment redistribution by large floods, and regulatory controls on PCB trends from 1970 to present. Profiles of PCBs (the sum of seven indicator PCB congeners) were reconstructed from sediment cores collected from an off-river rural reference site and from three depositional areas along the Rhône upstream and downstream from the city of Lyon, France. Core chronology was determined from radionuclide profiles and flood deposits. PCB concentrations increased progressively in the downstream direction, and reached a maximum concentration in 1991 of 281 g/kg at the most downstream site. At the rural reference site and at the upstream Rhône site, PCB concentrations peaked in the 1970s (maximum concentration of 13 and 78 g/kg, respectively) and have decreased exponentially since then. PCB concentrations in the middle and downstream cores were elevated into the early 1990s, decreased very rapidly until 2000, and since then have remained relatively stable. Congener profiles for three time windows (1965-80, 1986-93, and 2000-08) were similar in the three sediment cores from the Rhône and different from those at the rural reference site. The results indicate that permitted discharges from a hazardous-waste treatment facility upstream from Lyon might have contributed to high concentrations into the 1980-90s, but that industrial discharges from the greater Lyon area and tributaries to the Rhône near Lyon have had a greater contribution since the 1990s. There is little indication that PCB concentration in sediments downstream from Lyon will decrease over at least the short term.

Heavy metal and PCB spatial distribution pattern in sediments within an urban catchment—contribution of historical pollution sources

“…Polychlorinated biphenyls (PCBs) and heavy metals are two groups of pollutants extensively referred in the bibliography as resulting from anthropogenic activities which are found associated with sediments (Desmet et al 2012;Zhang et al 2016;Guan et al 2016). …”

Increase in soil erosion after agricultural intensification: Evidence from a lowland basin in France

“…also shown to be very efficient in transporting organic, radioactive and metallic pollutants to and within hydrosystems (Ayrault et al, 2014;Chartin et al, 2013;Desmet et al, 2012). For Europe, Cerdan et al (2010) compiled existing data at the plot scale and estimated the mean sheet and rill erosion rates on arable land to be 360 t km À2 yr À1 .…”

Contamination of Fish and Sediments from the Vistula River by Organochlorine Pesticides and PCBs

“…Since 2005, commercial fishing and consumption of select species of fish were banned as a result of PCB contamination of the Rhone River and several tributaries in France. High PCB levels (up to hundreds of µg/kg) have been detected repeatedly in sediment and fish in the Rhone River, particularly downstream from Lyon to the Mediterranean Sea [13]. In Brescia, Italy, a PCB production plant operated from 1930 to 1984 polluted soil and forage of surrounding fields, and caused significant contamination of meat and milk of the local cattle forage [14].…”