Estimating dioxin-like polychlorinated biphenyl toxic equivalents from total polychlorinated biphenyl measurements in fish

Abstract

Polychlorinated biphenyls (PCBs) are 209 related compounds, a dozen of which are known as dioxin‐like PCBs (dl‐PCBs) and are among the most toxic PCBs. Polychlorinated biphenyls contribute to many adverse effects to human health, including cancer, and are a major cause of fish advisories in North America. It is a common perception that individual PCB compounds, especially dl‐PCBs, rather than total PCB need to be quantified to predict the environmental hazard because of differences in their toxicity potential and distribution among various environmental matrices, including aquatic food webs. Because the current analytical methods for quantifying dl‐PCBs are complex and four‐ to fivefold more expensive, limited fish samples are analyzed for dl‐PCBs. Using what likely is the largest dl‐PCB fish data set (n = 912) with a wide distribution of fish species (n = 22), size (19–112 cm), weight (100–14,300 g), sex (male:female, 51:49), and PCB contamination level (20‐7,300 ng/g wet wt), we show that the comparatively less expensive and rapid measurements of total PCB in fish can be utilized to assess dl‐PCB‐related toxicological hazard, measured as 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin toxic equivalents (TEQ). A regression equation of dl‐PCB‐related TEQ (i.e., TEQdl‐PCB) to total PCB in fish is presented (TEQdl‐PCB = [2.56 × 10−5]CtotalPCB, r = 0.89, p < 0.001). The regression was evaluated by applying it to three independent data sets of substantial sizes (n = 55, 141, and 176). The TEQdl‐PCB estimated using the regression and total PCB measurements were within a reasonable factor of two to three of the TEQdl‐PCB calculated from the dl‐PCB measurements. The successful evaluation indicates versatility of the regression.

Assessment of PCDD/Fs and PCBs in Sediments from the Spanish Northern Atlantic Coast

“…It is shown that the composition of Aroclor Dl-PCBs and marker PCBs concentrations appeared to be linearly correlated (R 2 =0.90; Fig. 3) as it has been previously reported by other authors for bottom sediments from Rhone River (Okay et al 2009) and proved to be also a common feature in fish (Bhavsar et al 2007;Stachel et al 2007). …”

Detection and quantitative analysis of polychlorinated biphenyls in tilapia from Hawaiian waters

“…Many studies have reported PCB 118 as the major congener of PCBs in fish (Bhavsar et al, 2007). In the present study, this congener was also identified as the major contributor to the PCB concentrations in the fish samples.…”

Trends of persistent organic pollutants in American eel (Anguilla rostrata) from eastern Lake Ontario, Canada, and their potential effects on recruitment

“…Some limitations of earlier data were overcome by using recent data on congener ratios to estimate the concentrations of congeners not previously measured (e.g., Bhavsar et al, 2007bBhavsar et al, , 2008.…”

“…However, TEQs for PCDD/Fs in LO eels in 1980 (Ryan et al, 1984) and 1993(MOE, 2012 were estimated from mean concentrations of PCDD/Fs and the mean ratio of TEQs:PCDD/Fs calculated from data of the present study (Tables 2 and 4). Similarly, TEQs for PCBs (mo + no congeners) were calculated from measurements in 1980 (Ryan et al, 1984) and 1993(MOE, 2012 using the mean ratio of TEQs:PCBs of eels from the present study (Tables 2 and 4), a method validated for other Great Lakes fish (Bhavsar et al, 2007b). Estimated mean TEQ concentrations were 59.5 ± 35.6 and 14.4 ± 6.9 pg/g ww for eels collected in 1980 and 1993, respectively.…”