Exposure assessment at a PCDD/F contaminated site

Authors: Annika Åberg Mats Tysklind Tohr Nilsson Matthew MacLeod Annika Hanberg Rolf Andersson Sture Bergek Richard Lindberg Karin Wiberg

Publish Date: 2009/07/30

Volume: 17, Issue: 1, Pages: 26-39

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Abstract

The main pathway for human exposure to the highly toxic polychlorinatedpdioxins and polychlorinated furans polychlorinated dibenzopdioxins and dibenzofurans PCDD/Fs is via dietary intake Other exposure pathways may however be important in close proximity to point sources such as wood preservation sites where PCDD/F contaminated chlorophenols CP were previously used In this study a heavily PCDD/F contaminated CP saw mill site in Sweden was investigated Human exposure through a broad spectrum of exposure pathways was assessed Such studies are in demand since the question whether contaminated sites represent a current or future risk can only be answered by detailed sitespecific risk assessmentsSampling of exposure media soil air groundwater raspberries carrots potatoes grass milk eggs and chicken fodder was made Exposure media concentrations and congener distribution patterns were used to investigate the mobilization of PCDD/Fs from soil to the environment and to calculate exposure levels for adults Blood serum levels from siteexposed and control individuals were also analyzedCongener distribution patterns at the site were generally dominated by a specific marker congener 1234678HpCDF which is highly abundant in the polluted soil The dioxin toxic equivalents TEQ concentrations were notably elevated as compared to national reference samples for most exposure media and the marker congener was a major contributor to increased TEQ levels There were also indications of soiltoair volatilization of tetra and pentaCDD/Fs People who participated in the restoration of a contaminated building showed higher levels of 1234678HpCDF compared to controls and calculated exposure levels suggest that several sitespecific exposure routes may be of importance for the daily intake of PCDD/FDespite low mobility of higher chlorinated PCDD/Fs these contaminants were transferred from the polluted soil to the surroundings and into human tissue The extent of increased exposure from contaminated sites depends on the PCDD/F source strength of the soil composition of the pollution human activities and dietary patterns of the residents Impact from the contaminated soil on other exposure media was seen also for areas with low to moderate soil contamination In the future not only the levels of PCDD/F soil pollution but also the composition must be considered in risk assessments of contaminated sitesThe authors wish to thank residents of the study site who gave us permission to establish a garden plot on private land allowed sampling at private land and assisted in exposure media sampling Kramfors community and contracted environmental consultant agencies are acknowledged for guidance of the area and data sharing Katarina Stenman and Viktor Sjöblom Umeå University are acknowledged for plant identification and for grass and soil sampling respectively We also wish to thank Jaruslav Jurenka ALS Czech Republic who provided details about the blood serum analyses This work was a part of a project financed by the Swedish Environmental Protection Agency contract numbers E9205 and E506

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