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Latvian Journal of Chemistry, No 4, 2012, 316–323 DOI: 10.2478/v10161-012-0017-8

NUTRITION RECOMMENDATIONS FOR ESTONIAN FISHERMEN (DIOXINS AND DIOXIN-LIKE POLYCHLORINATED BIPHENYLS) O. Roots Estonian Environmental Research Institute, under Estonian Environmental Research Centre Estonian Marine Institute, University of Tartu E-mail: ott.roots@klab.ee

Nutrition survey of coastal fishermen was conducted in May 2010, when the fishing season was at its peak. More than half of the participants in the survey eat fish and fish products in April and May more than during the second half of the year At that time fishermen and their families eat fish the most. Thus, the amount of toxins found in the course of the survey, which the fishermen and their family members were exposed to, is greater than the average of the year. Based on an earlier monitoring of dioxins, the presence of dioxins can be stated to depend greatly on the type, age, size and other biological characteristics of the fish, and also on the fat content in the consumed fish. It is not recommen-ded for coastal fishermen and their family members to consume Baltic herring over 22 cm long (more than 8 year old) more than a couple of times a month. At present the Baltic herring in Estonian coastal waters is mostly 2–4 years old and eight-year-old Baltic herring forms a couple of per cent from the catch.

Keywords: Baltic Sea, Estonian fishermen, diet, fish, PCDD/Fs, DL-PCBs.

INTRODUCTION

The Stockholm Convention on the Persistent Organic Pollutants (POP) prohibits or restricts the use of persistent toxic chlorinated organic compounds, which are the most dangerous to the environment, including human health [1]. The convention divides chlorinated organic pollutants into three groups:

- pesticides; - industrial chemicals; - compounds created as a by-product of production process or in

rendering waste harmless. Polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans

(PCDF) and dioxin-like polychlorinated biphenyls (DL-PCB) belong to the latter group [1]. Dioxins are particularly dangerous to organisms at the top of the food chain (including people), because the presence of dioxins in these organisms may be hundreds of times higher than in the surroundings. According to the Finnish scientists, 80% of human exposure to dioxins is through fish and fish products [2]. The greater risk for women living by the Baltic Sea to get breast cancer and a lower birth weight of infants (especially boys) is due to high level of dioxins in the Baltic Sea fish [3]. If a child comes into contact with dioxins before the age of two, it may cause underdevelopment of the child’s brain [4, 5].

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Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and di-oxin-like polychlorinated biphenyls are bioaccumulable compounds with toxic characteristics that spread across the state borders through air, water, waste, and also food (including animal feed) and with the help of migratory species, and accumulate in water and terrestrial ecosystems far from the source of origin.

Most analyzed Estonian foodstuffs contain PCDDs, PCDFs and DL-PCBs in concentrations significantly less than the maximum levels provided for by the Commission Regulation (EC) No. 1881/2006 (setting maximum levels for certain contaminants in foodstuffs) and obviously do not pose any danger to the health of the residents of Estonia [6-10]

The situation may be different when we look at coastal fishermen who eat fish considerably more. The objective of the study was to assess the level of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and dioxin-like polychlorinated biphenyls (DL-PCB) that coastal fishermen are exposed to through fish and fish products. It has to be taken into account that due to the economic depression, intake of fresh fish probably increased in coastal fishermen's families and they used less foodstuffs bought from the store or from the market.

MATERIALS AND METHODS

Within the framework of national programme (2005–2020) on prevention of cardiovascular diseases the specialists from the National Institute for Health Development and the Estonian Society of Nutritional Science prepared in 2006 the publication “Estonia's nutrition and diet recommendations”. The assessment of the nutrition situation of the residents is based on nutrition and diet recom-mendations. The recommended average daily amount of fish is 2–4 portions, three times a week [10].

When preparing the nutrition recommendations, all developed countries today consider, first and foremost, the reduction of preventable chronic illness risk (cardiovascular diseases, malignant tumours, type II diabetes, osteoporosis etc.). In the Estonia's nutrition and diet recommendations fish have been conditionally divided into the following groups:

- relatively low-fat fish (fat under 2%) – pike-perch, pike, cod, burbot; - medium fat (up to 5%) – Baltic herring, flounder, bream, carp, smelt; - fatty fish (over 5%) – Baltic sprat, whitefish, vendace; - very fatty fish (over 15%) – eel, salmon, trout, common bleak,

sardine. One portion:

- 50 g fatty fish (trout, salmon); - 75 g low-fat fish (Baltic herring, cod, flounder, and bream).

According to the Ministry of the Environment (Table 1), fish caught the most in Estonia is the Baltic herring and Baltic sprat. Baltic sprat constituted 56.6% and Baltic herring 39.7% of the total amount (83548.2 tons) of fish caught from the Baltic Sea in 2009. Almost the entire amount of sprat is caught from the open sea, 64.5% of the Baltic herring from the open sea and 35.5% from the coastal waters. Only 3.7% of other fish species were caught from the Baltic Sea.

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Table 1. Catch from the Baltic Sea in 2009 (tons)*

Fish Coastal area Open sea Total Baltic herring 11 761.89 21 402.60 33 164.49 Baltic sprat 0.11 47 298.35 47 298.46 Perch 809.50 0.03 809.53 Flounder 287.58 0.125 287.71 Pike-perch 66.70 – 66.70 Salmon 5.39 0.004 5.40 Eel 4.32 – 4.32 Lamprey 0.15 – 0.15

––––––– * Ministry of the Environment (http://www.envir.ee/1015511).

As of 2002, the presence of dioxins in Estonian foodstuffs and also in the

Baltic Sea fish [11] and in fish caught from internal water bodies is studied on the initiative of the Ministry of Agriculture. The industrially most important fish species are the Baltic herring and sprat, but also perch, flounder and pike-perch. Contamination of fish with PCDD/Fs and DL-PCBs is presented in the Table 2.

Table 2. Presence of dioxins and dioxin-like PCBs (pg WHO-TEQ/g per wet weight) in Estonian fish [9]

Fish Number of samples PCDD/F DL-PCB Sum

(PCDD/F + DL-PCB) Baltic herring 73 2.3 ± 0.1 2.2 ± 0.2 4.8 ± 0.4 Baltic sprat 32 2.4 ± 0.2 2.6 ± 0.2 5.1 ± 0.3 Salmon 3 4.0 ± 0.3 5.0 ± 0.5 9.0 ± 0.8 Eel 3 2.2 ± 0.8 2.2 ± 0.8 4.4 ± 1.4 Perch 10 0.6 ± 0.1 0.7 ± 0.1 1.3 ± 0.2 Pike-perch 6 0.4 ± 0.0 0.4 ± 0.0 0.8 ± 0.0 Flounder 3 0.4 ± 0,1 0.9 ± 0,3 1.3 ± 0.4

Research shows that eating fish in Estonia has decreased by one fourth over

the last ten years. Among fresh fish Estonians prefer the Baltic herring and Baltic sprat, which in 2010 was consumed by 84% of the residents. It was found that 15% of the residents ate fish every week, 34% ate fresh Baltic herring at least once a month and 35% less than once a month. People over 50 years of age and with smaller income consumed more fresh Baltic herring and sprat every week [8, 12, 13]. The risk of coastal fishermen regarding dioxins is basically the same as for the rest of the residents of Estonia, but they consume more fish per person than on the average in Estonia. Nutrition survey of coastal fishermen was conducted in May 2010, when the fishing season was at its peak, to obtain information about Baltic Sea fish consumption by fishermen. Forty eight Estonian Baltic Sea coastal fishermen all around Estonia volunteered for the study. The average bodyweight of fishermen was 92 kg [14].

RESULTS AND DISCUSSION

How much fish can coastal fishermen eat, so that they would be out of danger and would not exceed the maximum amount of tolerable weekly intake

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of fish (calculated for 14 pg WHO-TEQ/bodyweight kilogram per week). The nutrition survey for coastal fishermen established that most respondents (82%) eat fish or fish products as the main course at least once a week, on the average 2.4 times a week. More than half of the respondents (74%) eat fish or fish products as an additional meal 2.6 times a week.

Based on the nutrition survey of coastal fishermen, - 31 out of 48 fishermen eat Baltic herring every day or at least once a

week (on the average 4.25 portions, i.e. 212.5 grams during one mealtime);

- 15 out of 41 fishermen eat sprats every day or at least once a week (on the average 2.56 portions, i.e. 128 grams during one mealtime).

The Baltic Sea herring and sprat belong to different groups by fat content – the sprat is a fatty fish and the Baltic herring is medium fatty [10].

The weekly amount of PCDD/F and DL-PCB, to which the coastal fisher-men are exposed to through fish, and the calculated number of weekly portions if the tolerable weekly intake (TWI) of fish does not exceed the limit is presented in the Table 3.

Table 3. The weekly amount of PCDD/Fs and DL-PCBs, which the coastal fishermen are exposed to through fish, and the calculated number of weekly portions if the tolerable weekly intake (TWI) of fish does not exceed the limit

Fish species

Number of affirmative answers by fishermen to the

questionnaire

TWI of fish not exceeding the limit, g.

Baltic herring 41 394 (1998)

513 (2005) Baltic sprat 12 296 Salmon 13 143 Eel 4 292 Perch 28 991 Pike-perch 9 1638 Flounder 17 987

–––––––– Average bodyweight of fishermen was 92.12 kg

Relatively few fishermen eat fish almost every day (Baltic herrings 15% and

sprats 5%). The nutrition survey for coastal fishermen does not explain the definitions “almost every day” and “at least once a week”, which makes the risk assessment of dioxins and dioxin-like biphenyls harder. Those definitions are partially overlapped [14]. For this reason we will take the total weekly amount of fresh fish eaten at all mealtimes per person (Table 4) as the basis of preliminary calculations.

Even the Baltic herring alone is currently consumed by costal fishermen considerably more than is permitted according to the maximum level of weekly intake of fish. Coastal fishermen and their family members should avoid eating so-called large Baltic herring (over 22 cm long and more than 8 years old) [8]. It is not recommended for coastal fishermen and their family members to consume Baltic herring over 22 cm long more than a couple of times a month (Figure 1).

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At present the Baltic herring in Estonian coastal waters is mostly 2–4 years old and eight-year-old Baltic herring form merely a couple percent of the catch [15].

Table 4. Intake of fresh fish by coastal fishermen during one week [16]

Fish species

Number of affirmative answers by

fishermen to the questionnaire

Weekly intake of fish

by fishermen, g

Total intake (PCDD/F + DL-PCB)*

Baltic herring 41 659 23.4 (1998) [17] and 18.0 (2005) [18]

Baltic sprat 12 241 11.4 Salmon 13 135 13.2 Eel 4 165 7.9 Perch 28 177 2.5 Pike-perch 9 351 2.0 Flounder 17 282 4.0

–––––– * TWI – tolerable weekly intake of fish – 14 pg World Health Organization (WHO) toxic

equivalent (WHO-TEQ) per kilogram of bodyweight.

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Age, years

pg W

HO

-TE

Q/g

ww

Fig. 1. Age-dependent dioxin concentrations (pg WHO-TEQ g wet weight) in the Baltic herring PCDD/F (black) and PCDD/F+DL-PCB(white circles) catches before 2009 [8].

Diversify health risks To diversify risks it is recommended to eat more low-fat and medium fat

fish, except Baltic herring. Baltic Sea salmon, salmon trout, eel (coastal fisher-men do not eat a lot of those fish, and in our coastal waters the presence of dioxin and dioxin-like polychlorinated biphenyls in them has been studied to a small extent), and Baltic herring over 22 cm long from the Estonian coastal waters of the Baltic Sea is not recommended for consumption more than twice a month.

Eat smaller fish

By eating younger fish the body is exposed to lower amounts of dioxins and dioxin-like polychlorinated biphenyls. Younger fish are also tastier.

In choosing between the smaller fish, difference shall be made between the Baltic herring and sprat from the Baltic Sea, and these fish should be eaten at different mealtimes.

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If you eat older (longer) fish, reduce the number of times you eat fish or the intake of such fish compared to the intake of younger fish Try to freeze (pickle, smoke) larger fish and try to eat them not very often,

so that the body could be cleansed from toxins in the meantime. Try to eat more fish which contain less dioxins and dioxin-like poly-

chlorinated biphenyls. Eat more low-fat Baltic Sea fish (perch, pike-perch etc.).

Filleting of fish

Fillet bigger fish and remove the skin. Dioxins and dioxin-like polychlorinated biphenyls accumulate mostly in the

fat of the fish (fat layer). By filleting it is possible to remove the fat layer from the centre of the fish fillet and belly flaps.

Frying, grilling, pickling, salting, smoking of fish

Frying does not decompose the dioxins or dioxin-like biphenyls in fish. However, some of the toxins will be released with the melted fish fat. The released fish fat may not be used for other foods such as gravy, soup etc.

Grilling, roasting or smoking should be preferred to frying because then the dioxins will drip from the fish with the fat. You can also choose the favour of pickling.

CONCLUSIONS

Eating fish is good for health. It is common knowledge that fish is a good source of omega-3 fatty acids, and that consumption of fish is good for the heart and cardiovascular system, but it is recommended to diversify risks. It means that the consumed fish should not all be very fatty.

By the Estonian [8,11] and Finnish data [19] the comparison of the levels measured 2002-2003 with the 2009 levels of PCDD/Fs and DL-PCBs shows that the mean levels have decreased in Baltic herring.

Coastal fishermen and their family members should avoid only eating the so-called big Baltic herrings (over 22 cm long and more than 8 years old). It is not recommended for coastal fishermen and their family members to consume Baltic herrings over 22 cm long more than a couple of times a month.

We recommend increasing the share of perch, pike-perch and flounder, as well as fish originating from inspected fish farms and imported from other states of the European Union in the daily food intake.

Nutrition recommendations for coastal fishermen

According to the Estonian nutrition and diet recommendations, at normal energy consumption a person may eat 2–4 portions of fish per day [10]. Based on the maximum intake of fish and fish preserves, in which case the summarized tolerable weekly intake (TWI) of dioxins and dioxin-like polychlorinated biphenyls is not exceeded, it is recommended for coastal fishermen to take into account the following:

- There is no dioxin hazard from eating 12 portions of perch, pike-perch and probably also pike from amongst low-fat fish and flounder from amongst

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medium fat fish a week, i.e. not more than 900 g a week (not over 130 g per day).

- In case of fatty fish it has to be taken into account that the maximum intake of one type of fish should not exceed 3 times a week and 2 portions at once, i.e. 6 portions a week (not over 300 g of one type of fish a week, i.e. 43 g per day). From amongst very fatty fish this group includes the salmon, eel, probably also salmon trout; from amongst fatty fish the sprat; and from amongst medium fat fish the Baltic herring.

Family members of coastal fishermen should reduce the weekly intake of fish based on their bodyweight. Said recommendations consider the average body weight of coastal fishermen to be 92.1 kg.

Acknowledgement

Thanks to the support of the Estonian Ministry of Agriculture it has been possible to study persistent organic pollutants in the diet of Estonian fishermen.

R E F E R E N C E S

1. Roots, O., Zitko, V., Kumar, K.-S., Sajwan, K., Loganathan, B.-G. (2011). Contamination Profiles and Possible Trends of Organohalogen Compounds in the Estonian Environment and Biota. In Global Contamination Trends of Persistent Organic Chemicals Ed. by B.-G. Loganathan, P. K.-S. Lam. CRC Press Taylor & Francis Group. 305–333

2. Kiviranta, H., Vartiainen, T., Tuomisto, J. (2002). Polychlorinated-p-dioxins, dibenzo-furans, and biphenyls in fishermen in Finland. Environmental Health Perspectives, 110, 355–361.

3. Rylander, L., Hagmar, L. (1995). Mortality and cancer incidence among women with a high consumption of fatty fish contaminated with persistent organochlorine compounds. Scand. J. Work Environ, Health., 21, 419–425.

4. Rylander, L., Strömberg, U., Hagmar, L. (1995). Decreased birth weight among infants born to women with a high dietary intake of fish contaminated with persistent organochlorine compounds. Scand. J. Work Environ. Health, 21, 368–375.

5. Ryan, J., Amirova, Z. (2001). Gender of children of Russian chemical producers exposed to dioxins. Organohal. Comp., 53, 37–40.

6. Roots, O. (2007). PCDDs, PCDFs and DL-PCBs in some selected Estonian and imported food samples. Fresenius Environ. Bull., 16, 1662–1666.

7. Roots, O., Simm, M., Kiviranta, H., Rantakokko, P. (2008). Persistent organic Pollutants (POPs): Food Safety Control in Estonia. In The Fate of Persistent Organic Pollutants in the Environment (NATO Science for Peace and Security). Ed. by E. Mehmetli and B. Kouma-nova. Springer, 173–185.

8. Dioksiinide ja dioksiinitaoliste polüklooritud bifenüülide ühendite sisalduse hindamine Eesti kalades (räimes), värskes lihas, võis ja rapsiõlis. Aruanne (Koostajad O. Roots, M. Simm) OÜ Eesti Keskkonnauuringute Keskus (Hankeleping 2009/161), Tallinn, 2009, 26 lk + lisad (http://www.vet.agri.ee/static/body/files/1233.Dioksiinide%20seire%202009.pdf).

9. Simm, M., Roots, O., Spilev, H. Dioksiinid eesti rannikumere kalades. http://www.lote.ut.ee/786146.

10. Koostajad, S., Vaask, T., Liebert, M., Maser, K., Pitsi, P.T., Saava, M., Sooba, E., Vihalemm, T., Villa, I. (2006). Eesti toitumis- ja toidusoovitused. Tervise Arengu Instituut ja Eesti Toitumisteaduse Selts. Tallinn. 80 lk.

11. Roots, O., Lahne, R., Simm, M., Schramm, K.-W. (2003). Dioxins in the Baltic herring and sprat in Estonian coastal waters. Organohal. Comp., 62, 201–203

12. Kala ja kalatoodete turg Eestis, Eesti Konjunktuuriinstituut, Tallinn, 2011, 160 lk. 13. Pomerleu, J., Mckee, M., Robertson, A., Kadziauskiene, K., Abaravicius, A., Vaask, A.,

Pudule, I., Grinberga, D. (2001). Macronutrient and food intake in the Baltic republics. Eur. J. Clin. Nutrition, 55, 200–207.

14. Möller, G. (2010). Rannakalurite toitumisuuring. Emor AS Põllumajandusministeerium. 58 lk. http://www.agri.ee/uuringud-statistika/.

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15. ICES. Report of the Baltic Fisheries Assessment Working Group (WGBFAS), 22–28April 2009, ICES Headquarters, Copenhagen, ICES CM 2009\ACOM:07, 626 pp.

16. Roots, O. (2011). Eksperthinnangu koostamine rannakalurite kokkupuutele dioksiinide ja dioksiinilaadsete polüklooritud bifenüülidega. Tallinn, 36 lk., (Eesti Vabariigi Põllumajandusministeerium - http://www.agri.ee/uuringud-statistika/).

17. Van den Berg, M., Birnbaum, L., Bosveld, A.T., Brunström, B., Cook, P., Feeley, M., Giesy, J.P., Hanberg, A., Hasegawa, R., Kennedy, S.W., Kubiak, T., Larsen, J.C., Leeu-wen, F.X., van Liem, A.K., Nolt, C., Peterson, R.E., Poellinger, L., Safe, S., Schrenk, D., Tillitt, D., Tysklind, M., Younes, M., Waern, F., Zacharewski, T. (1998). Toxic Equivalency Factors (TEFs) for PCBs, PCDDs, PCDFs for Humans and Wildlife. Environ. Health Persp., 106 (12), 775–792.

18. Van den Berg, Birnbaum, L., Denison, M., de Vito A.M., Farland, W., Feeley, T.M., Fiedler, H., Hakansson, H., Haws, L., Rose, M., Safe, D., Schrenk, C., Tohyama, C., Tritscher, A., Tuomisto, J., Tysklind, M., Walker, N., Peterson, R.E. Review. The 2005 World Health Organization reevaluation of Human and Mammalian Toxic Equivalency Factors for Dioxins and Dioxin-like Compounds. Toxicological Sciences, 2006, 93 (2), 223–241.

19. Hallikainen, A., Airaksinen, R., Rantakokko, P., Koponen, J., Mannio, J., Vuorinen, P.J Kiviranta, H. (2011). Environmental pollutants in Baltic Sea fish, EU-FISH II, presentation 13.09.2011, 36 pp.

DIĒTAS IETEIKUMI IGAUŅU ZVEJNIEKIEM

O. Rots

K O P S A V I L K U M S

Igauņu zvejnieku uztura pētījumi veikti 2010. gada maijā – laikā, kad zvejnieku uzturā ir visvairāk zivju. Pētījumos piedalījās 48 Igaunijas piekrastes zvejnieki, kas ēda galvenokārt Baltijas siļķes un Baltijas reņģes. Noteikts dioksīna daudzums šajās zivīs un sniegti ieteikumi to lietošanai uzturā.

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