PCDD, PCDF, and PCB exposure in current and former firefighters from Eastern Siberia

The current study examines whether the occupation of firefighting contributes to exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs). We compared serum dioxin concentrations and congener profiles of current firefighters (n = 13) with those of men who have ceased employment as firefighters (n = 17) and with men employed in occupations other than firefighter (n = 10). We found that compared to former or non-firefighters, current firefighters have higher levels of dioxins primarily due to the contribution of PCBs and to a lesser extent PCDFs. PCDFs were significantly higher in former firefighters compared to non-firefighters (p < 0.05). Comparisons with studies performed by other investigators suggest that local environmental conditions contribute to some of the elevation of PCBs. The congeners 1,2,3,4,6,7,8-heptachlorodibenzodioxin and PCB-114 were significantly higher in current firefighters when compared to former or non-firefighters. Moreover, levels of these congeners were inversely correlated with years since employed as firefighter (Spearman r = −0.610, p = 0.009 and Spearman r = −0.53, p = 0.03, respectively). The classes of dioxins show an overall decline with years since employed as firefighters, this decline is most evident with PCDDs (Spearman r = −0.46, p = 0.06). Together, the combination of evidence supports firefighting as a source of exposure to dioxins.

► We measured dioxin levels in the serum of firefighters as an indicator of occupational exposure. ► Serum dioxin concentrations were compared in current, former and non-firefighters. ► Total dioxins were highest in current firefighters and lowest in non-firefighters. ► Certain dioxin congeners were highest amongst the current firefighters. ► We conclude the evidence is consistent with firefighting as a source of dioxin exposure.