Lecture

Characterization of exposure pathways to PBDEs and HBCD - comparing exposure estimates with biomonitoring. NILU F

Thomsen, C.; Haug, L.S.; Frøshaug, M.; Huber, S.; Schlabach, M.; Becher, G.

Introduction
Brominated flame retardants such as the polybrominated diphenyl ethers (PBDEs) and
hexabromocyclododecane (HBCD) are well known to be present in indoor air and dust and
contribute to human exposure. However, the influence of indoor contamination on human body
burdens is not fully understood. Some recent studies have suggested that for many individuals
indoor exposures may be comparable to or greater than the dietary intake. The aim of this study
was to characterize exposure pathways to PBDEs and HBCD and compare exposure estimates
with biomonitoring.
Materials and Methods
A study group of 41 female volunteers from the greater Oslo area, Norway was established.
Informed consent was obtained from all the participants and the project was approved by the
Regional Committee for Medical Research Ethics. Samples of house dust as well as indoor air
from the women¿s residences were collected between February and May 2008. The women also
donated serum samples and completed a questionnaire covering demographic information, life
style factors as well as dietary habits. PBDEs and HBCD were determined in all samples types.
Results and discussion
The sum of six tri- to hexa BDEs (BDE-28, 47, 99, 100, 153 and 154) in the women¿s serum
ranged from 0.67 to 30 ng/g lipids, while BDE-209 ranged from 0.46 to 11 ng/g lipids. Of these
PBDEs, only BDE-28 and 47 were found above LOQ in air, in concentrations ranging from
0.78-58 and 1.3-63 ng/m3, respectively. In addition BDE-66 and BDE-49/71 were occasionally
detected. In house dust, the sum 6 PBDEs ranged from 9.3 to 662 ng/g, while the sum of ¿, ß,
and ¿-HBCD ranged from 55-2808 ng/g. Individual PBDE congeners were well correlated
within each sample type. Significant correlations were also found between individual PBDE
concentrations in air and dust as well as between sum 6 PBDE in dust and sum 6 PBDE in
serum. Assuming an ingestion of house dust of 50 mg per day, the intake of sum 6 PBDE ranged
from 0.008 to 0.47 ng/kg bw/day (mean 0.064 ng/kg bw/day). The corresponding value for sum
HBCD was 0.039-2.2 ng/kg bw/day (mean 0.30 ng/kg bw/day). The intake from food has not
been assessed in this cohort yet, but ongoing multivariate regression analyses point to
statistically significant associations between serum concentrations of PBDEs and some variables
in the indoor environment as well as the diet. The dietary intake was estimated to range from
0.14-3.6 ng/kg bw/day (mean 1.1 ng/kg bw/day) for sum 7 PBDEs (sum 6 PBDE + BDE-183)
and 0.06-0.87 (mean 0.27 ng/kg bw/day) for sum HBCD in one of our previous studies on
persons exposed to background contaminated food in Norway. These preliminary findings
suggest that exposure from house dust is important with respect to body burdens of BFRs,
HBCD in particular.

Methane observations from the Zeppelin Observatory at Svalbard - Variability and influence of regional transport. NILU F

Myhre, C.L.

Contribution of traffic to urban air quality and mitigation strategies in European Cities. NILU F

Hak, C.; Larssen, S.; Randall, S.; Guerreiro, C.; Denby, B.

Global anthropogenic emissions of mercury and their future scenarios. NILU F

Pacyna, J.M.; Pacyna, E.G.; Sundseth, K.

Impact of snow on the NH autumn and winter circulation in an ensemble of coupled forecasts. NILU F

Orsolini, Y.; Balsamo, G.; Doblas-Reyes, F.; Vitart, F.; Weisheimer, A.