Semi-volatile organic pollutants: sources and occurrence in food and the environment

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1 5 th CEFSER Training Course Analysis of chemical contaminants in food and the environment 7-11 May 2012 Semi-volatile organic pollutants: sources and occurrence in food and the environment Prof. Dr. Biljana Škrbić Nataša Đurišić-Mladenović University of Novi Sad, Faculty of Technology Centre of Excellence in Food Safety and Emerging Risks Novi Sad, Serbia

2 Semi-volatile organic pollutants or compounds (SVOCs) belong to different chemical classes, with many of them classified as Persistent Organic Pollutants (POPs) or Peristent Toxic Substances (PTSs)

3 Some chemical classes belonging to SVOCs are: polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDD), and dibenzofurans (PCDFs), etc.

4 These organic compounds are resistant to environmental degradation through chemical, biological, and photolytic processes. Because of this, they have been observed to

5 persist in the environment, transfer long distances from the emission sources, bioaccumulate in organisms, leading to the biomagnification in food chains, and have impacts on the environment and human health with a very broad spectrum of harmfull effects.

6 These are also the main properties of SVOCs including those officially classified as priority POPs by the United Nations Environmental Programme under the Stockholm Convention.

7 12 Stockholm (old) POPs Pesticide Industrial Chemical By-product Aldrin + Chlordane + DDT + Dieldrin + Endrin + Heptachlor + Mirex + Toxaphene + Hexachlorobenzene PCB + + PCDD + PCDF +

8 Stockholm Convention criteria for POPs persistency In order to classify a chemical as POP, evidence of its prolonged half-life in different environmental compartment should exist: Half time in water Half time in soil > 2 months > 6 months Half time in sediments > 6 months

9 POPs potential for long-range environmental transport One of the criteria to include a compound into the POPs group, is that the monitoring data, environmental fate properties and/or model results should demonstrate that it has a potential for long-range environmental transport through air and water, that could lead to its deposition in a receiving environment distant from the sources of the release.

10 Transboundary Movement of SVOCs (POPs) through GLOBAL DISTILLATION phenomenon Chemicals are semivolatile Evaporate over warmer regions and condense in colder atmospheres Widespread distribution Can affect regions where use is nonexistent

11 POPs potential to bioaccumulate their concentration is gradually built up over time in a living organism, because they cannot be broken down for use by the organism (that is, these chemical cannot be metabolized), leading to the biomagnification the process through which higher concentrations of these pollutants are reached in organisms higher up in the food chain, generally through a series of prey-predator relationships.

12 Amounts (medians) of indicator PCBs in human milk from various countries ng/g fat Brazil Fiji Philippines Australia Hungary New Zealand Bulgaria China USA Ireland Finland Egypt Norway Croatia Ukraine Russia Sweden Romania Netherlands Belgium Germany Luxembourg Spain Italy Slovak Rep. Czech Rep.

13 POPs toxicity POPs show adverse effects to human health or to the environment. After these pollutants are put into the environment, they are able to stay in the system for decades causing problems such as cancer, birth defects, learning disabilities, immunological, behavioral, neurological and reproductive discrepancies in human and other animal species.

14 Endocrine Disruptor Chemicals (EDCs) Public concern about contamination by POPs increased recently because several of these compounds are identified as hormone disrupters (EDC), which can alter normal function of endocrine and reproductive systems in humans and wildlife.

15 POPs enter the environment through different routes, either through point or diffuse sources during their production, use or after disposal.

16 There is also a possibility for their unintentional production when they are accidentally formed or released as a byproduct from various activities, such as industrial or diverse combustion processes (e.g. PCDDs/PCDFs, PAHs). POPs Intentionally Unintentionally Industrial chemicals (e.g.pcb) OCPs PAHs Dioxins Furans

17 The atmosphere often plays a key role in the SVOCs transport within the immediate vicinity of the sources as well as over great distances. Finally, they are DEPOSITED in different environmental compartments (water, soil, biota) through dry or wet deposition.

18 SVOCs are HYDROPHOBIC ORGANIC CHEMICALS, which once released in the environment tend to bind to the organic fraction either in soil, dust, and sediment particles, and to accumulate in animals and humans.

19 AIR-TO-PLANT TRANSFER of SVOCs is the first step in terrestrial food chain accumulation, and therefore a starting point for transfer of these compounds to animals and humans.

20 AGRICULTURAL PLANTS are of particular interest because they are a key link in the chain atmosphere-food being used as feed, introducing the SVOCs to an animal milk and meat, which consumption accounts for much of background human exposure to persistent lipophilic organic pollutants.

21 opolychlorinated BIPHENYLS (PCBs) oorganochlorine PESTICIDES (OCPs) opolycyclic AROMATIC HYDROCARBONS (PAHs)

22 PCBs are man-made chemicals synthesized with different chlorination degrees.

23 Although theoretically 209 congeners are possible, the actual number of PCB compounds (congeners) found in the environment is much lower. THE MOST IMPORTANT TO MONITOR IN THE ENVIRONMENT AND FOOD are:

24 12 congeners that show toxicological properties similar to 2,3,7,8- tetrachlorodibenzo-pdioxin (TCDD), representing one of the most toxic contaminant known, and, therefore, termed dioxin-like PCBs. Their toxic effects include immuno- and reproductive toxicity, carcinogenic potency, negative influence on the development of central nervous system, etc. TCDD

25 The other group of PCBs non-dioxin-like do not show dioxin-like toxicity but have another toxicological profile, acting on the central nervous system, the thyroid and the endocrine system after high incidental intakes or after bio-accumulation in the body upon long-term intake. Six of them (PCB 28, 52, 101, 138, 153 and 180), the so-called INDICATOR PCBs, are most commonly determined in the environment as they are frequently the most abundant in various environmental matrices and cover a wide range of chlorination (from 3 to 7 chlorine atoms).

26 EXPOSURE It has been found that more than 90% of the total daily intake of these contaminants is derived from food with inhalation contributing the majority of the remainder.

27 The HIGHEST LEVELS of most persistent pollutants were observed in food of animal origin but there is growing evidence that cereals and vegetables could be the PREDOMINANT SOURCES of PCBs for humans.

28 Several countries, such as France, the Netherlands, UK, Germany, USA and Canada, have defined maximum tolerances of PCBs in some edible products. These tolerances are expressed as total content of investigated PCBs and are based on specific congeners, primarily on dioxin-like congeners.

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30 Form for reporting of congener-specific analytical results of non-dioxine-like PCBs in food 28, 52, 101, 138, 153, 180- sum PCB-6

31 opolychlorinated BIPHENYLS (PCBs) oorganochlorine PESTICIDES (OCPs) opolycyclic AROMATIC HYDROCARBONS (PAHs)

32 OCPs are a diverse group of chlorinated contaminants that have been used as pesticides.

33 DDT is probably best known for its dual nature: although remarkably effective in destroying certain living things that are harmful to plants and animals, it can also be extremely dangerous to humans and the environment.

34 After some OCPs were banned for use since the 80s, common daily food items such as eggs, milk, poultry, meat and fish have been used for monitoring the residual levels of OCPs, as the major source of human background exposure to OCPs is through food of animal origin.

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36 As regards food of animal origin, one efficient way to avoid large-scale contamination is to control and monitor the level of OCP residues present in animal feeds before being fed to the husbandry animals.

37 To ensure that pesticide residues are not found in food or feed at levels presenting an unacceptable risk for human consumption, maximum residue levels (MRLs) have therefore been set by the European Commission and also by other international authorities (EPA, Codex Alimentarius).

38 MRLs are set for a wide range of food commodities of plant and animal origin, and they usually apply to the product as placed on the market.

39 Data sets on pesticides MRLs are available online, including the MRLs set by EC:

40 opolychlorinated BIPHENYLS (PCBs) oorganochlorine PESTICIDES (OCPs) opolycyclic AROMATIC HYDROCARBONS (PAHs)

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42 Polycyclic aromatic hydrocarbons (PAHs) are fused-ring aromatic compounds formed in incomplete combustion of organic material during a number of activities (automobile exhausts, domestic heating, biomass burning, industrial activities, oil spillage, etc.). PAHs generally are found throughout the environment in air, water and soils in the form of COMPLEX MIXTURES, never as individual compounds.

43 In general, the composition of PAH profiles varies depending on the source (combustion conditions) and the environmental compartment. Since there is no international agreement on which panel of individual PAHs should be analyzed and reported in order to characterize distinct emission sources, PAH lists released from different organizations do contain different compounds.

44 Sixteen different PAHs are prioritized by the US- Environmental Protection Agency (EPA) and also by the European Commission. European Commission list consists of 16 individual PAHs as being major concern for human health, while EPA listed also some of lower molecular-weight PAHs such as naphthalene, phenanthrene, anthracene, or fluoranthene due to their occurrence in environmental samples.

45 In order to distinguish the set of PAHs listed by EC from a set of also 16 compounds that has been addressed by the US EPA, known as 16 EPA PAHs, the terminology 15+1 EU priority PAHs was chosen.

46 A number of PAHs have been shown to be genotoxic carcinogens. From all hydrocarbons detectable in the human environment the most intensively studied species, is benzo[a]pyrene classified by the International Agency for Research on Cancer (IARC) as a probable human carcinogen, and it has been traditionally used as indicator of carcinogenic PAHs.

47 For non-smoking humans, the major routes of exposure to PAH are from food and to some extent from inhaled air. Food can be contaminated by: (i) environmental PAHs that are present in air, soil or water; (ii) industrial food processing methods; and (iii) home food preparation.

48 PAHs have been detected in a variety of foods, notably vegetables as a result of the deposition of airborne PAHs, and in fish and mussels from contaminated waters. The waxy surface of vegetables and fruits can concentrate low molecular mass PAHs through surface adsorption and particle-bound high molecular mass PAHs can contaminate the surface due to atmospheric fallout.

49 PAHs can also contaminate foods during industrial smoking, heating and drying processes that allow combustion products to come into direct contact with food. Contamination of cereals and of vegetable oils (including seed oils and olive residue oils) with PAH usually occurs during technological processes like direct fire drying, where combustion products may come into contact with the grain, oil seeds or the oil.

50 PAHs could be also formed as a result of certain food preparation methods, such as grilling, roasting and smoking. The highest PAH concentrations are usually found in grilled/barbecued foods (especially meat and meat products grilled under prolonged and severe conditions), foods smoked by traditional techniques (fish in particular), and mussels and other seafood from polluted waters.

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53 Smoked and grilled food may contribute significantly to the intake of PAHs if such foods are a large part of the usual diet. However, generally the major contributors to PAH intake in the average diet are oils and fats, cereals, fruits and vegetables, due to their higher consumption rates.

54 Maximum levels of benzo(a)pyrene in different food commodities are specified in EC Regulation 1881/2006

55 Foodstuffs Oils and fats (excluding cocoa butter) intended for direct human consumption or use as an ingredient in foods Maximum levels (μg/kg wet weight) Smoked meats and smoked meat products 5.0 Muscle meat of smoked fish and smoked fishery products, excluding bivalve molluscs. The maximum level applies to smoked crustaceans, excluding the brown meat of crab and axcluding head and thorax meat of lobster and similar large crustaceans (Nephropidae and Palinuridae) Muscle meat of fish, other than smoked fish 2.0 Crustaceans, cephalopods, other than smoked. The maximum level applies to crustaceans, excluding the brown meat of crab and axcluding head and thorax meat of lobster and similar large crustaceans (Nephropidae and Palinuridae) Bivalve molluscs 10.0 Processed cereal-based foods and baby foods for infants and young children Infant formulae and follo-on formulae, including infant milk and follow-on milk Dietary foods for special medical purposes intended specifically for infants

56 However, European Food Safety Authority (EFSA) adopted an opinion on PAHs in food on 9 June 2008, according to which benzo(a)pyrene is not a suitable marker for the occurrence of PAHs in food

57 and that a system of four specific substances (PAH4) or eight specific substances (PAH8) would be the most suitable indicators of PAHs in food.

58 EFSA also concluded that a system of eight substances (PAH8: benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(ghi)perylene, chrysene, dibenz(a,h)anthracene and indeno(1,2,3- cd)pyrene) would not provide much added value compared to a system of four substances (PAH4).

59 Thus, based on the conclusions of EFSA, the current system of using benzo(a)pyrene as the only marker for the group of PAHs has not been maintained.

60 New maximum levels for the sum of four substances (PAH4) is introduced, whilst maintaining a separate maximum level for benzo(a)pyrene in the latest EC Regulation 835/2011 which shall apply from September 1, 2012.

61 The separate maximum level for benzo(a)pyrene is maintained to ensure comparability of previous and future data. After a certain time of implementation of this amendment and on basis of new data that will be generated in future, the need for retaining a separate maximum level for benzo(a)pyrene should be readdressed.

62 This new system of the indicator PAH4 group would ensure that PAH levels in food are kept at levels that do not cause health concern and that the amount of PAHs can also be controlled in those samples in which benzo(a)pyrene is not detectable, but where other PAHs are present.

63 As regards the sum of PAH4, lower bound concentration should be used as the basis for compliance decisions, which means concentrations of undetected compounds should be considered to be 0.

64 Foodstuffs Oils and fats (excluding cocoa butter) intended for direct human consumption or use as an ingredient in foods Smoked meats and smoked meat products OLD maximum levels (μg/kg wet weight) 1881/2006 NEW maximum levels (μg/kg) 835/2011 Benzo(a)pyrene Benzo(a)pyrene Sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthen e and chrysene until as from as from until as from

65 Data for smoked meat and fish have shown that the lower maximum levels are achievable. Still, adaptations of current smoking technology may be necessary in some cases. Therefore, a two step procedure should be established for smoked meat and fish, which grants a transition of two years from the date of application of this Regulation before lower maximum levels become applicable.

66 Foodstuffs Muscle meat of smoked fish and smoked fishery products, excluding smoked sprats, canned smoked sprats, bivalve molluscs, heat treated meat and heat treated meat products. The maximum level for smoked crustaceans applies to muscle mat from appendages and abdomen. In case of smoked crabs and crab-like crustaceans (Brachyura and Anomura) it applies to muscle meat from appendages OLD Maximum levels (μg/kg wet weight) 1881/2006 NEW maximum levels (μg/kg) 835/2011 Benzo(a)pyrene Benzo(a)pyrene Sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene until as from as from until as from

67 Foodstuffs OLD Maximum levels (μg/kg wet weight) 1881/2006 Benzo(a)pyrene NEW maximum levels (μg/kg) 835/2011 Benzo(a)pyren e Sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene Bivalve molluscs smoked Processed cereal-based foods and baby foods for infants and young children Infant formulae and folloon formulae, including infant milk and follow-on milk Dietary foods for special medical purposes intended specifically for infants

68 NEW FOOD COMMODITIES IN REGULATION ON PAHs COCOA BUTTER and derived products COCONUT OIL intended for direct human consumption or use as an ingredient in food SMOKED SPRATS AND CANNED SMOKED SPRATS BIVALVE MOLLUSCS (fresh, chilled, or frozen); HEAT TREATED MEAT AND HEAT TREATED MEAT PRODUCTS SOLD TO THE FINAL CONSUMER

69 COCOA BUTTER contains higher levels of PAHs than other oils and fats, mainly due to inappropriate drying practice of the cocoa beans and the fact that cocoa butter can not be refined as other vegetable oils and fats.

70 Cocoa butter is a main constituent of cocoa raw products (e.g. cocoa beans, cocoa mass, nibs or liquor) and is present in chocolate and other cocoa products often consumed by children. It is therefore necessary to establish maximum levels for PAHs in cocoa beans and derived products, including cocoa butter.

71 Smoked sprats and canned smoked sprats have been found to contain higher levels of PAHs than other smoked fish, which is the reason why specific maximum levels is established for these type of commodities in order to reflect what is achievable in such foodstuffs.

72 High levels of PAHs have been found in some types of heat treated meat or meat products sold to final consumer. These levels are avoidable of appropriate processing conditions and equipment are used. It is therefore appropriate to establish maximum levels for PAHs in meat and meat products that have undergone a heat treatment process known to potentially results in formation of PAHs, i.e. only grilling and berbecuing.

73 Foodstuffs Cocoa beans and derived products Coconut oil intended for direct human consumption or use as an ingredient in food Smoked sprats and canned smoked sprats (sprattus sprattus); bivalve molluscs (fresh, chilled, or frozen); heat treated mean and heat treated meat products sold to the final consumer OLD Maximum levels (μg/kg wet weight) 1881/2006 NEW maximum levels (μg/kg) 835/2011 Benzo(a)pyrene Benzo(a)pyrene Sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene 5.0 μg/kg fat as from μg/kg fat as from until μg/kg fat as from

74 ANALYSIS OF SVOCs In general, the analysis of organic contaminants in food and environmental samples is not an easy task due to many interfering compounds present in large quantities in comparison to low levels of the contaminants. The challenge for SVOCs analysts is to maximize their recoveries and minimize the interferences by proper extraction and clean-up procedures and also using the selective/specific/sensitive instrumental techniques.

75 M.S. El-Shahawi et al. / Talanta 80 (2010) Classical methods for determination of SVOCs consist of extraction and clean up and they are time consuming and use large quantities of organic solvents

76 The latest trend is to MINIMISE: the number of manipulations, the solvent volumes, the number of evaporation steps, the use of toxic solvents, to automate the preparation step as far as possible.

77 It is developed originally as sample preparation technique for multiresidue analysis of pesticide, but now its application scope has been broaden towards POPs, mycotoxins and other organic pollutants.

78 M.S. El-Shahawi et al. / Talanta 80 (2010) UHPLC-APPI-MS-MS PAHs

79 SVOCs have been the subject of the research in CEFSER Lab for many years resulting in articles published in international journals, concerning either food safety or the environmental issues

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81 5 th CEFSER Training Course Analysis of chemical contaminants in food and the environment 7-11 May 2012 Toxic and very long-lasting, persistent organic pollutants endanger the well-being of our planet and all living beings, (...) Only decades ago, most of the 12 POPs targeted for international action under the treaty being negotiated did not exist, and now they are in the air, water, soil around the planet and in us all, and they last for generations,... UNEP Press Release (2000): Klaus Töpfer, Executive Director of the United Nations Environment Programme (UNEP), Speech held on the 10th of November 2000, UNEP, Nairobi/ Geneva