Exposure to brominated flame retardants in electronics recycling : air and human plasma levels

Abstract: Polybrominated diphenyl ethers (PBDEs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and 1,2-bis(2,3,4,5,6-pentabromophenyl)ethane (DeBDethane) were analysed in air and blood samples from workers at an electronics recycling facility. The samples were collected regularly for 18 months and were analysed by isomer specific GC/MS analysis in both electron impact (EI) and negative chemical ionisation (NCI) mode.In addition, triiodotyronine (T3), thyroxin (T4) and thyroid stimulating hormone (TSH) were monitored and put in relation to the workers’ PBDE concentration in blood.Breathing zone air samples showed that the electronics dismantlers were highly exposed to PBDE #209 in comparison with other workers in the facility (30 ng/m3 and 8 ng/m3, respectively). However, for BTBPE and the other PBDE congeners no such difference was found. It was also shown that when dismantling small electronic products (computers and household electronics) the air levels were higher than when dismantlinglarger products (photocopiers). Monitoring dust fractions (“total dust”, inhalable dust and respirable dust) revealed that the PBDE #209 concentration was more than ten times higher in the inhalable dust fraction than the traditionally used “total dust” fraction (“total” 15 ng/m3, inhalable 192 ng/m3), which was not the case for the other BFRs.The sampler for inhalable dust collects particles of larger size more efficiently than the “total” dust sampler. PBDE #209 was found to bind to a higher extent to larger particles in the air. However, PBDE #209 was also present in the respirable fraction (3.1 ng/m3) that reaches the alveolar region in the lungs, making it available for uptake.The levels of PBDEs detected in the workers’ blood were within the range of the general population in Sweden, except for PBDE #183 and #209 which were slightly elevated (1.2 pmol/g l.w. and 5.7 pmol/g l.w., respectively) among the dismantlers. No clinical effect could be seen on the thyroid hormone status in the workers, caused by the PBDE concentration. Steady state blood concentration estimations based on levels in the respirable dust fraction suggested that the increase for PBDE #209 was due to occupational air-borne dust.To study biological samples with high levels of PBDEs to identify possible metabolites from PBDEs and other bromine containing compounds, whales from the Mediterranean Sea were analysed. PBDEs were found at high concentrations in the range of 66-8100 ng/g l.w.. Three methoxylated tetraBDEs (MeO-TeBDE) were identified in the whale samples at a range of 2-630 ng/g l.w.. Several unidentified organobromine compounds were also detected in the whales.