Polychlorinated biphenyl (PCB) contamination of apartment building and its surroundings by construction block sealants

Because of their superior properties polychlorinated biphenyl (PCB) containing sealants were used in the construction industry in the 1960's and 1970's. The PCB content and distribution of individual PCB-congeners in sealant and soil samples were determined using gas chromatography (GC) with selective-ion monitoring mass spectrometry (MS-SIM). In the present case study, the total concentration of extractable PCBs in sealant samples ranged from 8 300 mg/kg to 108 700 mg/kg. The concentrations were highest on the northern side of the building studied. In soil samples the concentrations ranged from 0.03 mg/kg to 6.62 mg/kg. The concentrations were the highest in the immediate vicinity of the building and declined with distance. The risk assessment carried out was based not only on the total PCB concentrations but also on the congener specific analyses. Toxicity of specific congeners was estimated on the basis of 2,3,7,8-TCDD equivalents. The highest deterministic risk value with congener specific information and exposure pathway as soil ingestion was 4.90 × 10^-5. Using probabilistic assessment along with lognormal distributions for the parameters the 95 percentile value for the toxicity risk was 3.02 × 10^-7. For the purpose of this study, only PCB exposure by dermal contact and ingestion of soil was evaluated. There was no significant toxicity risk to the children.