Historical Inputs of PCDDs, PCDFs, and PCBs to a British Columbia Interior Lake:  The Effect of Environmental Controls on Pulp Mill Emissions

Abstract

A sediment core collected from Kamloops Lake, British Columbia, was used to assess historical inputs of polychlorinated dioxin and furans (PCDD/Fs) from a pulp mill and the effects of recent environmental controls. Principal components analysis reveals that four groups of compounds can be found in the sediments: moderately chlorinated PCDD/Fs produced during the bleaching of pulp with chlorine (e.g., TCDF); PCDD/Fs that have been produced by condensation of polychlorinated phenoxyphenol contaminants during pulping (e.g., HxCDDs); highly chlorinated PCDD/ Fs that are derived from mixed sources (e.g., OCDD); and a series of PCBs that are probably derived from mixed sources. Strong correlations of CB13, CB15, and CB37 with the moderately chlorinated PCDD/Fs suggest that these PCBs have been produced in-situ by the pulp mill. In particular, CB15 is found in quantities rivaling those of total TCDF. In the 1930s-1950s, sediments exhibit minor contamination by the PCBs and higher chlorinated dioxins and furans. With the construction of the mill in 1965, large quantities of HxCDD and the tetra-chlorinated PCDD/Fs were released. Technological changes at the pulp mill have effected a drastic reduction in pulp mill PCDD/Fs in the 1990s.

Persistent Organic Pollutants

“…The effects of a pulp mill installation on the sedimentary loadings of PCBs and PCDD/Fs to Kamloops Lake, British Columbia, were reported by MacDonald et al (1998). This study is interesting in that the historical profile for PCBs follows a similar trend to that observed in other lake cores from temperate climates, except the observation of peak concentrations for most of the congeners occurring in the 1950s, despite the later initiation of pulp bleaching processes.…”

Levels and homologue profiles of PCDD/Fs in sediments along the Swedish coast of the Baltic Sea

“…Direct emissions to Baltic Sea waters have likely decreased as well, due to cessation of chlorophenol and vinyl chloride production and changes in production processes in the surrounding countries. One of the factors believed to have improved pollution levels is the shift from using chlorine gas to other bleaching agents in pulp mills (MacDonald et al 1998). Levels of PCDD/Fs in surface sediments are thus expected to be declining in coastal as well as off-shore areas.…”

Estimation of sources and inflow of dioxins and polycyclic aromatic hydrocarbons from the sediment core of Lake Suwa, Japan

“…The historical changes in deposition rate of dioxins and PAHs have been determined using sediment cores in USA, Europe, and Japan (Chirenzelli et al, 2001;Hosomi et al, 2003;Macdonald et al, 1998;Masunaga et al, 2001a;Rose and Rippey, 2002;Sakai et al, 1999;Sakai et al, 2002;Takeda et al, 2003). These studies used radioactive isotopes (e. g. 210 Pb, 137 Cs) to determine sedimentation rates in aquatic environment.…”