Deriving \u201cpotential target values\u201d of PCDD/F in animal feed: the role of livestock at the interface between feed and food chain

Maria José Abud Clariget,Janine Kowalczyk,Birgit Wobst

doi:10.1007/s00003-021-01350-0

Maria José Abud Clariget, Janine Kowalczyk + Show 1 more

Open Access

https://doi.org/10.1007/s00003-021-01350-0

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Abstract

Linking derivation of potential target values of PCDD/Fs in animal feed with risk assessment for consumer protection is a challenge when tolerable weekly intake (TWI) and transfer factors from feed to food are considered. Generally, maximum values for feed and food are set separately without considering the feed and the food producing animal as an important factor along the food chain from farm to fork. Levels of contaminants in feed can accumulate in animals and their products effect consumers at the end of the food chain. Hence, the process of setting legal maximum levels of contaminants should account for transfer from feed consumed by food producing animals into animal products for human consumption. Here, we calculated potential target values of PCDD/F in feed to ensure that animal products such as milk from dairy cows, eggs from laying hens and pork and pork products from fattening pigs are safe for human consumption. In our approach, we calculated potential target values of PCDD/Fs in animal feed using transfer factors for PCDD/F-TEQs from feed to milk fat, eggs fat, and fat in pork and pork products, taking into account the tolerable weekly intake derived by European Food Safety Authority. We assumed equal proportions of WHO-PCDD/F-TEQ and WHO-PCB-TEQ in feed. Potential target values of PCDD/F in feed are expressed as the quantity of toxicologically evaluated PCDD/Fs, expressed in WHO toxic equivalents (WHO2005-PCDD/F-TEQ) per kg feed with 12% moisture. In the current approach, derived values would be 10–54 times lower than the current legal maximum level of 0.75 ng WHO2005-PCDD/F-TEQ per kg feed (12% moisture), according to Directive 2002/32/EC as amended.

Highlights

Polychlorinated dibenzodioxins and -furans (PCDD/Fs), commonly termed “dioxins”, and dioxin-like polychlorinated biphenyls (DL-PCBs) are two- or three-ring structures that can be chlorinated to varying degrees
We demonstrate an approach that considers several steps in the food chain, regarding PCDD/Fs in feed which is consumed by food producing animals, transferred to food for human consumption
With the calculated low potential target values of the tolerable weekly intake (TWI) (EFSA 2018), it was difficult to comply with the PCDD/F levels in the feed ration, because the calculated levels were 10–54 times lower as the current legal value (0.75 ng/kg feed with 12% moisture)

Summary

Introduction

Polychlorinated dibenzodioxins and -furans (PCDD/Fs), commonly termed “dioxins”, and dioxin-like polychlorinated biphenyls (DL-PCBs) are two- or three-ring structures that can be chlorinated to varying degrees. The 17 compounds, which are chlorinated in the 2, 3, 7, 8 position, share the same mode of action, are highly toxic and at the same time persistent. They accumulate in the adipose tissue of animals and humans and are considered relevant for human (and animal) health. The toxicity equivalency factors (TEFs) for the individual congeners are between 0 and 1, indicating the magnitude of their toxicity in relation to 2, 3, 7, 8-TCDD. The TEF values including DL-PCB were first proposed by the WHO in 1997 (WHO1998-TEQs; van den Berg et al 1998) and were re-evaluated by a WHO working group in 2005 (WHO2005-TEQs; van den Berg et al 2006, in the following referred as “WHO2005-TEQ”)

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