Elsevier

Science of The Total Environment

Volume 574, 1 January 2017, Pages 120-127
Science of The Total Environment

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in Zhejiang foods (2006–2015): Market basket and polluted areas

https://doi.org/10.1016/j.scitotenv.2016.09.038Get rights and content

Highlights

  • We summarized levels and estimated dietary intake of PCDD/Fs and PCBs in Zhejiang foods from market and polluted areas.

  • Market data (2009–2015) were consisting of 537 food samples in 13 food groups, PCDD/Fs and DL-PCBs TEQs were below the EU ML.

  • High TEQ concentrations were found for foods collected from vicinity of MWI and E-waste disassembling areas.

Abstract

In this study, we measured the levels of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in 620 foods collected during 2006–2015 from Zhejiang market, a municipal waste incinerator (MWI) and E-waste disassembling areas.

For market retail foods, the levels of PCDD/F TEQs, PCDD/F plus dioxin-like PCB (DL-PCB) TEQs, and the concentrations of six indicator PCBs were generally below the EU ML. The average TEQ values for the 13 food groups were 42% of EU ML for PCDD/Fs and 32% for PCDD/Fs + DL-PCBs. Some foods of animal origin were close to the corresponding EU ML: pork (PCDD/F TEQ, 79% of ML; PCDD/F + DL-PCB TEQ, 84% of ML); infant formula (90% of PCDD/F ML) and beef (96% of PCDD/F ML; PCDD/F + DL-PCB TEQ, 78% of ML). The estimated dietary intake for the general population was 22.0 pg TEQ (kg body weight (bw)) 1 month 1, which was below the standard of 70 pg TEQ (kg bw) 1 month 1 set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

For the MWI and E-waste disassembling sites, high concentrations of PCDD/Fs and PCBs were measured in all foods tested. The corresponding TEQ in (1) freshwater fish, (2) chicken egg, (3) chicken meat and (4) chicken liver was (1) 1.4-fold (MWI, PCDD/F TEQ), (2) 11.2-fold (MWI,) and 1.6-fold (E-waste disassembling sites), (3) 20.7-fold and (4) 3.3-fold greater than EU ML, respectively. Considering the worst situation (highly polluted foods were consumed), the estimated dietary intake for local residents were 244 (MWI) and 240 pg TEQ (kg bw) 1 month 1 (E-waste disassembling sites), approximately 3.5-fold greater compared to the standard 70 pg TEQ (kg bw) 1 month 1 set by JECFA, indicating high risk could have been imposed on the health of local residents.

Introduction

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs, dioxins) and polychlorinated biphenyls (PCBs) belong to the lipophilic persistent organic pollutants (POPs). These pollutants have similar chemical structures, physicochemical behaviors and toxicological effects. PCDD/Fs are useless byproducts of human industry, produced during waste combustion, petroleum refining, metallurgy production and synthesis of certain chlorinated chemicals (e.g. pentachlorophenol) (Ding et al., 2012). In contrast, PCBs are commercial products used once as transformer oil (Ling et al., 2008, Xing et al., 2010) and paint ingredients (Anezaki and Nakano, 2014). These contaminants can be transported long distances via air and water, can sink in soil or sludge, persist in the environment, bioaccumulate through the food chain and, finally, deposit in higher animals including humans. Dioxin like POPs can impose adverse effects upon human health; e.g. as lesions, chloracne, developmental defects etc. (Kim et al., 2014, Lyche et al., 2015, Masuda, 2001).

Food is the main route of exposure to POPs and approximately 90% of human exposure to PCBs and PCDD/Fs originates from foods, especially those of animal origin (e.g. meat, egg and milk) (Zhang et al., 2015). So far, numerous surveys, from market basket (Costopoulou et al., 2013, Du et al., 2012, Mihats et al., 2015, Roszko et al., 2014, Tornkvist et al., 2011) to polluted areas (Aslan et al., 2010, Hoogenboom et al., 2015, Ling et al., 2008, Song et al., 2011, Xing et al., 2010), have been published revealing the status of PCBs and PCDD/Fs pollution in foodstuffs worldwide. The market basket is widely adopted to monitor the levels of various contaminants, pesticides, veterinary drugs, illegal ingredients etc., which offers the possibility of estimating dietary exposure for the general population. However, the food items collected from retail circulation are usually not produced locally; they might be produced from other places or countries. Before an investigation begins, it is important to know what the typical pollutants are and what is the approximate range of the pollutants. Further, if foodstuffs are polluted, it is not always easy to track the pollution source accurately.

By contrast, food samples produced in typically polluted areas, e.g. E-waste disassembling areas and municipal waste incinerator (MWI) vicinity, usually have specific pollution profiles according to transportation of the contaminants and accumulation along the food chain. The levels of these food components are important for estimating risks to human health via the dietary route and because they are good indicators of local pollution status. In areas where farming and mining coexist, 65%, 50% and 34% of all the mine-impacted field rice was predicted to fail China National Food standards for Cd, As and Pb, respectively (Williams et al., 2009). In Guangdong Guiyu, Qingyuan and Zhejiang Taizhou, typical large E-waste disassembling areas in China, pollutant PBBs, PBDEs, PCBs, PCDD/Fs and heavy metals from the E-waste recycling processes were detectable at high levels in tissue samples. Residents in the E-waste exposure areas are faced with a potentially greater daily intake of these pollutants compared to residents in the control areas (Labunska et al., 2015, Song and Li, 2014, Song et al., 2011, Xing et al., 2010). MWI is another potential source of pollution. In recent years, intense local opposition to incineration has increased as a result of the fears surrounding the potential environmental impact and the human health risks from emissions of MWI byproducts, especially PCDD/Fs (Schuhmacher et al., 2004).

In the past 10 years, Zhejiang CDC have participated in several rounds of a nation-wide food contaminants survey (2009–2015), and carried out three province-wide projects (2006–2014) to monitor food contaminants in typical polluted areas in Zhejiang, including E-waste disassembling areas in Taizhou and MWI sites in Yiwu. > 600 food samples have been analyzed and annual assessment reports submitted to government. In this study, we summarized levels and estimated dietary intake of PCDD/Fs and PCBs in Zhejiang foods from both market basket and typical polluted areas.

Section snippets

Sampling

A total of 620 food samples were collected and analyzed during 2006–2015. These samples were of three types: (1) market basket foods (n = 537); 2), foods collected from suspect polluted area, e.g. vicinity of an MWI (n = 15); and (3), foods collected from E-waste disassembling sites (n = 68).

As part of the annual national food contaminants survey in China, 13 categories of market basket foods (rice, fresh milk, milk powder, infant formula, marine fatty fish, marine shell fish, marine fish oil,

Results and discussion

Table 1, Table 2 summarized the PCDD/F TEQs, PCDD/F plus DL-PCB TEQs and the concentrations of indicator PCBs in 620 foods collected and analyzed during 2006–2015. Since fresh weight (or wet weight, ww) and fat weight based results for lipophilic POPs are usually mixed in the literature, we reported on a wet weight (ww) basis and a fat weight basis (in bold in Table 1, Table 2), fat contents were also given. For detailed information of congener concentrations, please see Supplementary materials.

Conclusions

As a summary of Zhejiang provincial food contaminants survey, this study reports the levels of PCDD/Fs and PCBs in foods collected from Zhejiang market, MWI and E-waste disassembling sites, and dietary intake has been estimated for general population and local residents.

For indicator PCBs, concentrations from market, MWI and E-waste disassembling sites foods were all below EU MLs.

For market retail foods, levels of PCDD/Fs and DL-PCBs were below the maximum limits (ML) set by the EU. The average

Acknowledgements

This study was sponsored by the following foundations: (1) the National Natural Science Foundation of China (81472986); (2), the Zhejiang Provincial Program for the Cultivation of High-Level Innovative Health talents; (3), the Program Co-cultivated by Zhejiang Province-National Health and Family Planning Commission of China (2015PYA003) and (4), the Zhejiang Provincial Health and Family Planning Commission Scientific Foundation (2015KYA051). The authors are grateful to International Science

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