Results of biomonitoring in workers exposed to chlorinated biphenyls during recycling of transformers and capacitors

Introduction: In 2008, routine environmental monitoring detected a PCB source in the harbour area of Dortmund (Germany) as shown by elevated PCB levels in air as well as in vegetables grown in this area. However, the origin of the PCBs was not found until in May 2010, human biomonitoring revealed a transformer recycling company as source of these emissions. In this company, PCB-containing transformers were recycled on a large scale. In order to clarify the extent and possible health effects of this additional PCB-exposure, a surveillance program for all persons was initiated. As one part of this program, human biomonitoring was offered to all persons.  

Methods: So far, 669 persons participated in the human biomonitoring program. Plasma samples of the participants were analysed for the six indicator PCBs (PCB 28, 52, 101, 138, 153, 180) and 12 dioxin-like PCBs using standardized analytical methods.  

Results: Employees of the recycling company including former or contract workers (n=116) showed the highest PCB levels measured so far in Germany. Median (95th perc.) for PCB 28 and (Sigma) PCBs was 0.31 (13.1) microg/l plasma) and 3.7 (62.9) microg/l plasma, respectively. Elevated PCB levels were also identified in persons working in companies in close surroundings.  

Discussion: Despite their ban more than two decades ago, PCBs obviously still pose a present occupational health risk. Our results prove the high potential of contamination for persistent organic pollutants like PCBs and the need to strictly adhere to (and possibly improve) occupational hygiene standards in order to avoid absorption of these probable human carcinogens (IARC group 2A). Biomonitoring should be imperative for persons handling possibly contaminated material.