Transfer of persistent organic pollutants in food of animal origin – Meta-analysis of published data

Abstract

The transfer of POPs in food of animal origin has been studied by a meta-analysis of 28 peer-reviewed articles using transfer rate (TR) for milk and eggs and bioconcentration factors (BCF) for eligible tissues after establishing an adapted methodology. TRs of the most toxic PCDD/Fs into milk were generally elevated and even higher into eggs. BCFs in excreting adult animals varied widely between studies complicating to hierarchize tissues or congeners, even if liver and fat seemed to bioconcentrate more than lean tissues. Short time studies have clearly shown low BCFs contrarily to field studies showing the highest BCFs. The BCFs of PCDD/Fs in growing animals were higher in liver than in fat or muscle. In contrast to easily bioconcentrating hexachlorinated congeners, octa-and heptachlorinated congeners barely bioconcentrate. PCB transfer into milk and eggs was systematically high for very lipophilic congeners. Highly ortho-chlorinated PCBs were transferred >50% into milk and eggs and even >70% for congeners 123 and 167 into eggs. BCFs of the most toxic PCBs 126 and 169 were significantly higher than for less toxic congeners. BCFs seem generally low in PBDEs except congeners 47, 153 and 154. DDT and its metabolites showed high bioconcentration. Differences between tissues appeared but were masked by a study effect. In addition to some methodologic recommendations, this analysis showed the high transfer of POPs into eggs, milk and liver when animals were exposed justifying a strong monitoring in areas with POP exposure.

A Method Scope Extension for the Simultaneous Analysis of POPs, Current-Use and Banned Pesticides, Rodenticides, and Pharmaceuticals in Liver. Application to Food Safety and Biomonitoring

“…Whether it is for residue research in the context of food safety, or in the context of biomonitoring, the liver is an extremely interesting matrix, as it is one of the organs of that concentrates more quantity of chemicals [18]. The range of substances that it is interesting to investigate in one or another circumstance is quite similar, since the substances that are of concern from the point of view of food safety generally also concern from the point of view of the environmental pollution and their effects on wildlife [11,[19][20][21].…”

Deriving “potential target values” of PCDD/F in animal feed: the role of livestock at the interface between feed and food chain

“…Lorber et al 2000;Huwe and Smith 2005) while others defined it differently (e.g. Amutova et al 2021).…”

“…The most conservative approach would have been to use a TF of the toxicologically most relevant congeners with the highest transfer of toxicity. A recent meta-analysis shows mean transfer rates of 34.0 ± 6.3% and 39.1 ± 12.6% for TCDD from feed into milk and eggs, respectively (Amutova et al 2021). For DL-PCB-126, the toxicologically most relevant DL-PCB congener, the transfer rates were 40 ± 11.4% and 37.7 ± 19.6% from feed into milk and eggs, respectively.…”

“…Potential target values for DL-PCBs or WHO 2005 -PCDD/F-DL-PCB-TEQ were calculated separately for transfer into milk and results were compared. There is less literature reporting transfer factors for DL-PCBs at steady state conditions (Amutova et al 2021;Lorenzi et al 2020;VDI 2019). PCDD/F concentrations in the total feed ration should consider potential target values for farm animals that serve to protect these animals thereby ensuring that foods derived from them are safe for human consumption (VDI 2005(VDI , 2019.…”

“…1 kg to 3 kg in accordance to its live weight gain of up to 800 g per day until reaching 100-120 kg during the fattening period (Jeroch et al 2008). Hence, achievement of stable conditions is difficult to achieve in fattening pigs (Amutova et al 2021). If exposure periods are not sufficiently long to achieve steady state conditions, accumulation of PCDD/F would be underestimated.…”