Results of the monitoring of non dioxin-like PCBs in food and feed

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Article
European Food Safety Authority
EFSA Journal
EFSA Journal 2010; 8(7):1701 [35 pp.].
doi
10.2903/j.efsa.2010.1701
Acknowledgements

EFSA wishes to thank the EFSA’s staff members Valeriu Curtui, Alessandro Carletti, Pietro Ferrari and Stefan Fabiansson for the support provided to this EFSA scientific output. Special thanks to Peter Fürst, and Alexander Kotz for their valuable comments.

Type
Scientific Report of EFSA
On request from
EFSA
Question Number
EFSA-Q-2010-00970
Approved
22. Juli 2010
Published
30. Juli 2010
Affiliation
European Food Safety Authority (EFSA), Parma, Italy
Note
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Abstract

Non dioxin-like polychlorinated biphenyls (NDL PCBs) are persistent organic chemicals that accumulate in the environment and humans and are associated with a broad spectrum of health effects. Processing and distribution of PCBs has been prohibited in almost all industrial countries since the late 1980s but they still can be released into the environment from electrical appliances, building paint and sealants and waste sites that contain PCBs. In 2002 the European Commission prescribed a list of actions to be taken to reduce the presence of dioxins and PCBs in food and feed and Member States were recommended to monitor the situation. A total of 12,563 food and feed samples collected in the period 1995 2008 from 18 EU Member States, Iceland and Norway were retained for a detailed analysis of the occurrence of the six indicator NDL PCBs (# 28, 52, 101, 138, 153, and 180). Overall, 18.8% of the results for single congeners were below the limit of quantification (LOQ) but their distribution varied highly between food and feed groups. PCB-153 and PCB 138 were the most commonly detected congeners. In food, the highest mean contamination level was observed in fish and fish derived products followed by eggs, milk and their products, and meat and meat products from terrestrial animals. The lowest contamination was observed in foods of plant origin. A similar pattern was observed in feed where high contamination was reported in feed containing fish derived products and comparatively very low levels in feed of plant or mineral origin. The sum of the six NDL-PCBs was on average close to five times higher than the sum of the 12 dioxin-like PCBs. This relationship varied across food groups and is presumably related to the origin of samples and the contamination source. Country specific clustering has been observed in several food and feed groups.

Summary

Polychlorinated biphenyls (PCBs) are a widespread class of persistent organic chemicals that accumulate in the environment and humans and are associated with a broad spectrum of health effects. PCBs were widely used for many applications, especially as dielectric fluids in transformers, capacitors and coolants. Due to their toxicity and classification as persistent organic pollutants, processing and distribution of PCB has been prohibited in almost all industrial countries since the late 1980s but they still can be released into the environment from building paint and sealants and poorly maintained hazardous waste sites that contain PCBs. People are exposed to PCBs primarily through contaminated food.

Depending on the number of chlorine atoms and their position, 209 PCB congeners are possible. Based on structural characteristics and toxicological effects, PCBs are divided into dioxin like PCBs (DL PCBs) showing toxicological properties similar to dioxins and non dioxin-like PCBs (NDL PCBs) which do not share the dioxin’s toxic mechanism. Some NDL PCBs have been shown to elicit neurological, endocrine, immunological and carcinogenic effects. Several international agencies classify PCBs as probably carcinogenic to humans.

In evaluating the contamination situation, six congeners (# 28, 52, 101, 138, 153, and 180) were chosen as indicators for the occurrence of NDL PCBs. The Scientific Panel on Contaminants in the Food Chain of EFSA (CONTAM Panel) noted in its Scientific Opinion related to the presence of NDL PCBs in feed and food that the sum of the six indicator PCBs represented about 50 % of the total NDL-PCB in food. The EU Commission is currently discussing to lay down maximum levels for the sum of the six indicator NDL-PCBs in food and feed.

In 2002 the European Commission prescribed a list of actions to be taken to reduce the presence of dioxins and DL PCBs in food and feed and later introduced regular monitoring by Member States of food and feed, including, if possible, also NDL PCBs. Data on the presence of dioxins and PCBs in food and feed have been reported on a regular basis to the Commission. In April 2008 the Commission handed the collected information to the European Food Safety Authority (EFSA) for assessment.

A total of 11,214 food and 1,349 feed samples collected in the period 1995 2008 from 18 EU Member States, Iceland and Norway were retained for a detailed analysis. Overall, 18.8 % of the results for single congeners were below the limit of quantification (LOQ). PCB-153 and PCB-138 contributed the most to the sum of the six NDL-PCB congeners followed by PCB 180, PCB 28, PCB 101 and PCB 52 in that order, but relatively high variations were observed for each congener throughout food and feed groups. The contribution of PCB-153 and PCB-138 together consistently comprised at least 50% of the overall sum of the six congeners in each food group.

The highest mean of food contamination levels were observed in several fish and fish product categories followed by products of terrestrial animals. The lowest values were found in fruits and vegetables. Similarly the highest mean of feed contaminations were found in fish oil while most of other feed groups had mean levels below 1 µg/kg.

Regression analysis showed that the sum of the six NDL-PCBs were on average close to five times higher than the sum of the 12 DL-PCBs. This relationship varied across food groups and is presumably related to the origin of samples and the contamination source.

The current assessment includes results from both random and targeted monitoring but a clear separation of the two sampling groups was not possible. The lack of such sampling information and the irregular coverage of food and feed groups over time did not allow for an accurate time trend analysis to be performed. To improve the validity of any assessment of the presence of dioxins and PCBs in food and feed in Europe it is important to carry out random testing and separate reporting of a sufficient number of samples in each food and feed group. Targeted sampling during contamination incidences should be clearly indicated as such in the reporting.

Keywords
Polychlorinated biphenyls, non dioxin-like polychlorinated biphenyls, occurrence, food, feed
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Number of Pages
35