between the two cores is difficult because the analyses do not consider the same
compounds. The content of dichlorodiphenyldichloroethane (DDE), a degradation
product of dichlorodiphenyltrichloroethane (DDT), a chlorinated insecticide used
until 1970, drops sharply after its total ban in the early 1970s.
4.2 Metals (Ag, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn) and Arsenic
(As) at the Seine River Outlet (1935–2005)
Considering the OUT 1 trends, the maximum metal EF occurred before 1965 (Fig. 5).
Metal regulation started in the 1970s (Circulaire July 4, 1972, limiting the metal
discharges from the surface treatment industry) so that the decontamination started
~10 years before the social responses to contamination. This pattern is first due to the
industrial delocalisation outside of the centre of Paris and then from its suburbs;
second, to changes in industrial practices, which include the gradual recycling of
metals (e.g. in plating, in the 1980s); and third, to gradual use restrictions and then
bans on Cd (its use as pigment was banned in 1995), Hg (in thermometers in 1999)
and leaded gasoline (2000) [36].
Fig. 5 Evolution of metal enrichment factors – 5-year averages – in the Seine River sediment
archives at the basin outlet OUT
1 (1935–2005) [25]
Sedimentary Archives Reveal the Concealed History of Micropollutant. . .
283
compounds. The content of dichlorodiphenyldichloroethane (DDE), a degradation
product of dichlorodiphenyltrichloroethane (DDT), a chlorinated insecticide used
until 1970, drops sharply after its total ban in the early 1970s.
4.2 Metals (Ag, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn) and Arsenic
(As) at the Seine River Outlet (1935–2005)
Considering the OUT 1 trends, the maximum metal EF occurred before 1965 (Fig. 5).
Metal regulation started in the 1970s (Circulaire July 4, 1972, limiting the metal
discharges from the surface treatment industry) so that the decontamination started
~10 years before the social responses to contamination. This pattern is first due to the
industrial delocalisation outside of the centre of Paris and then from its suburbs;
second, to changes in industrial practices, which include the gradual recycling of
metals (e.g. in plating, in the 1980s); and third, to gradual use restrictions and then
bans on Cd (its use as pigment was banned in 1995), Hg (in thermometers in 1999)
and leaded gasoline (2000) [36].
Fig. 5 Evolution of metal enrichment factors – 5-year averages – in the Seine River sediment
archives at the basin outlet OUT
1 (1935–2005) [25]
Sedimentary Archives Reveal the Concealed History of Micropollutant. . .
283