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Food Additives & Contaminants: Part B: Surveillance Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tfab20
Total mercury in canned tuna sold in Canada in 2006 a
a
a
Robert W. Dabeka , Arthur D. Mckenzie & Donald S. Forsyth a
Food Research Division, Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada K1A 0L2 Accepted author version posted online: 11 Nov 2013.Published online: 03 Jan 2014.
Click for updates To cite this article: Robert W. Dabeka, Arthur D. Mckenzie & Donald S. Forsyth (2014) Total mercury in canned tuna sold in Canada in 2006, Food Additives & Contaminants: Part B: Surveillance, 7:2, 110-114, DOI: 10.1080/19393210.2013.856036 To link to this article: http://dx.doi.org/10.1080/19393210.2013.856036
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Food Additives & Contaminants: Part B, 2014 Vol. 7, No. 2, 110–114, http://dx.doi.org/10.1080/19393210.2013.856036
Total mercury in canned tuna sold in Canada in 2006 Robert W. Dabeka*, Arthur D. Mckenzie and Donald S. Forsyth Food Research Division, Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada K1A 0L2
Downloaded by [National Sun Yat-Sen University] at 15:35 31 December 2014
(Received 12 September 2013; accepted 13 October 2013) Total mercury was measured in 156 composites prepared from 936 samples of canned tuna sold in Canada in 2006. Each composite comprised a single brand. Yellowfin tuna contained the lowest concentrations, averaging 0.066 mg/kg. Skipjack tuna contained slightly higher concentrations, averaging 0.132 mg/kg. The highest average concentration was found in the Albacore tuna: mean 0.325 mg/kg, range 0.174–0.507 mg/kg. The second highest concentration among the 49 albacore composites was 0.469 mg/kg. There were 72 composites for which the type of tuna was not specified. The mercury in these averaged 0.095 mg/kg and ranged from 0.016 to 0.237 mg/kg. Keywords: mercury; canned tuna; survey levels
Introduction Mercury is a nerve toxicant (Health Canada 2007) and most dietary mercury in Canada results from fish consumption (Dabeka et al. 2003). Thus, targeted monitoring of fish is necessary for developing regulations and guidelines and setting fish consumption recommendations (EPA 2007; Health Canada 2007). Tuna is a predatory fish which is known to accumulate mercury. In Canada, consumption of tuna is greater than that of any other fish, with over 40,000 metric tonnes consumed in 2004 (Health Canada 2007). Tuna is overwhelmingly sold as canned, and retail sales of canned tuna in the year 2007 were $156 million Canadian dollars, 48% of all canned seafood sales (AAFC 2007). As a result of its high consumption, canned tuna has been analysed for mercury in Canada (Dabeka et al. 2004), the United States of America (Zook et al. 1976; Shim et al. 2004; Ikem & Egiebor 2005; Burger & Gochfeld 2006; Gerstenberger et al. 2010; Groth 2010; FDA 2013) and other countries (Cugurra & Maura 1976; Acra et al. 1981; Kyle & Ghani 1983; Voegborlo et al. 1999; Velasco-Gonzalez et al. 2001; Knowles et al. 2003; Dhindsa 2004; Emami Khansari et al. 2005; Waqar 2006; Chung et al. 2008; Rahimi et al. 2010; Storelli et al. 2010; Martorell et al. 2011; Miklavcic et al. 2011; Mol 2011; Park et al. 2011; Salaramoli et al. 2012). Survey results for even the same species of tuna have varied considerably. For example, reports of average mercury concentrations in canned albacore (often labelled as “white”) tuna have ranged from a low of 0.130 mg/kg in Korea (Park et al. 2011) to highs of 0.407 mg/kg (Burger & Gochfeld 2006) and *Corresponding author. Email: [email protected] © Copyright of the Crown in Canada 2014 Health Canada
0.502 mg/kg (Gerstenberger et al. 2010) found in the United States of America. Such wide variations in levels suggest the importance of each country conducting its own survey of mercury in canned tuna available for sale domestically. While a previous Canadian survey of mercury in predatory fish had been conducted (Dabeka et al. 2004), it only included 39 canned tuna samples. To update these data and obtain a more valid estimate of mercury intake from consumption of canned tuna, a survey of total mercury in 156 composites prepared from 936 samples of canned tuna sold in Canada was conducted in 2006 and the results are presented here. Experimental Sampling A pre-market survey and retail data provided by Nielsen Marketing Inc. (Markham, Ontario, Canada) were used to determine the products available for sale in Canada as well as the amount of the individual products purchased by consumers. The Bureau of Biostatistics and Computer Applications (Health Canada, Ottawa, Canada) designed a sampling plan. Under a contract to Noraxx Inspections Inc. (Mississauga, Ontario, Canada), 936 samples in total were purchased from 16 stores in Toronto and Vancouver. Tuna samples were opened, drained, composited into 156 composites and homogenised at the Health Products and Food Branch Food Laboratory in Longueuil, PQ, Canada. Each composite contained six cans of tuna of same brand with between one and six different lot numbers within the same composite, depending on availability. Sixteen different brands were represented.
Food Additives & Contaminants: Part B Total mercury analyses
Downloaded by [National Sun Yat-Sen University] at 15:35 31 December 2014
Analyses were performed using the reagents, instrumentation and methodology described previously (Dabeka et al. 2002). After a low-temperature nitric/hydrochloric acid and hydrogen peroxide digestion, measurements were made using a CETAC-6000A dedicated mercury analyser equipped with CETAC ASX-500 autosampler and ADX auto-dilutor (CETAC, Omaha, NE, USA). The stock standard (1000 mg/kg) was purchased from SCP Science Inc. (Baie d’Urfe, Quebec, Canada). Each sample was analysed only once. Results are reported on a fresh weight basis.
Method validation Quality control measures for each analytical batch included three blanks, two blank spikes, one sample spike (in duplicate for both the unspiked and spiked sample) and duplicates of two different standard reference materials (SRMs) with certified mercury concentrations (SRM 1566b Oyster tissue from the US National Institute of Standards and Technology (NIST, Gaithersburg, MD, USA) and Dorm-2 dogfish muscle from the National Research Council of Canada (NRC, Ottawa, Ontario, Canada)). A cross-check (X-check) standard from a different manufacturer (SPEX CertiPrep Inc., Metuchen, NJ, USA) was included in each batch for standard verification during the run. The limit of detection (LOD) for the solutions was calculated for each analytical batch by multiplying the standard deviation of three reagent blanks by three. Sample LODs were calculated by multiplying the solution LOD by the dilution volume of 50 mL and dividing by the weight of the actual sample taken for analysis.
Results and discussion Method validation Quality control results are presented in Table 1, which are satisfactory except for a higher concentration found for the
111
NIST Oyster Tissue SRM. All sample concentrations were above the sample LOD, which for the average sample weight of 1.56 g was 0.89 ng/g averaged over all batches, and ranged from 0.12 to 2.8 ng/g. The precision between duplicate samples averaged 3.0% relative standard deviation (RSD). The precision for duplicate measurements of the high-concentration Dorm-2 SRM averaged 2.35% RSD, varying from 0.16% to 3.7% RSD, and that of the low-concentration Oyster tissue SRM averaged 4.08% RSD, varying from 1.1% to 14% RSD. The precision for the unspiked duplicate canned tuna samples averaged 2.53% RSD at an average concentration of 0.090 mg/kg.
Mercury levels in canned tuna samples Canned tuna mercury concentrations were highest in albacore tuna, averaging 0.326 mg/kg and ranging 0.174– 0.507 mg/kg (Table 2). The levels are slightly higher than those found previously in Canada: mean 0.260 mg/ kg, range 0.193–0.384 mg/kg (Table 3). Both the current and previous mean levels agreed well with USA means of 0.31 mg/kg (Burger & Gochfeld 2006), 0.35 mg/kg (FDA 2013) and 0.383 mg/kg (Groth 2010), as well as with means of 0.280 mg/kg in Iran (Salaramoli et al. 2012) and 0.263 mg/kg in Hong Kong (Chung et al. 2008). All of the above results were considerably higher than the average of 0.130 mg/kg reported for 66 albacore samples in Korea (Park et al. 2011). Of the different species, canned yellowfin tuna contained the lowest concentrations of mercury, averaging 0.066 mg/kg and ranging 0.046–0.095 mg/kg (Table 2). This average was lower than that of 0.085 mg/kg found previously in Canada (Dabeka et al. 2004) (Table 3). However, the previous value could have been skewed upward by one sample, likely mislabelled, containing 0.587 mg/kg. Evidence for this was the median concentration of 0.037 mg/kg for the whole data set (Table 3). Average concentrations reported elsewhere for yellowfin tuna were higher than those observed in Canadian studies, examples being 0.33 mg/kg in the USA (Zook et al.
Table 1. Quality control data. Series number 1 2 3 4 5 6 Mean Certified:
Avg. blank, ng/mL
Avg. blank std. dev. ng/mL
Solution LOD, ng/mL
Avg. blank spike, % recovery
Avg. sample spike, % recovery
SRM NIST 1566b Oyster tissue, mg/kg
SRM NRC Dorm-2, mg/kg
X-check, ng/mL
0.202 0.137 0.198 0.087 0.110 0.173 0.151
0.002 0.006 0.010 0.004 0.029 0.006 0.010
0.004 0.017 0.03 0.012 0.086 0.018 0.028
104 96 103 97 99 98 99
89 96 101 88 88 90 92
0.061 0.052 0.044 0.065 0.052 0.071 0.058 ± 0.010 0.037 ± 0.002
4.76 4.91 4.7 4.58 3.73 4.19 4.48 ± 0.44 4.64 ± 0.26
0.92 0.96 1.02 0.87 0.88 1.0 0.94
112
R.W. Dabeka et al.
Table 2. Summary of total mercury levels (mg/kg) in canned tuna. Species Albacore Skipjack Yellowfin Not specified All
N
Mean
Median
Minimum
Maximum
49 21 14 72 156
0.326 0.132 0.066 0.095 0.170
0.302 0.126 0.063 0.085 0.125
0.174 0.057 0.046 0.016 0.016
0.507 0.305 0.095 0.237 0.507
Downloaded by [National Sun Yat-Sen University] at 15:35 31 December 2014
Table 3. Literature data on mercury levels in canned tuna. Country, reference Australia (Dhindsa 2004) Canada (Dabeka et al. 2004)
USA (Burger & Gochfeld 2004) USA (Burger & Gochfeld 2006) USA (FDA 2013) USA (Groth 2010) USA (Ikem & Egiebor 2005) USA (Gerstenberger et al. 2010) USA (Shim et al. 2004) (N = 240 in total)
USA (Zook et al. 1976) Hong Kong (Chung et al. 2008) Iran (Salaramoli et al. 2012) Iran (Rahimi et al. 2010) Iran (Emami Khansari et al. 2005) Italy (Cugurra & Maura 1976)
Italy (Storelli et al. 2010) Korea (Park et al. 2011) Lebanon (Acra et al. 1981) Libya (Voegborlo et al. 1999) Mexico (Velasco-González et al. 2001) New Guinea (Kyle & Ghani 1983) Saudi Arabia (Waqar 2006) Slovenia (Miklavčič et al. 2011) Spain (Martorell et al. 2011) Turkey (Mol 2011) UK (Knowles et al. 2003)
Canned tuna species
N
Average (median) mg/kg
Range, mg/kg
Tuna Albacore Skipjack Yellowfin Other White/Albacore Light Light White/Albacore Gourmet Light Albacore Albacore Light Tuna White/Albacore Light Light (veg. oil) Light (soy oil) Light (water) White/Albacore (water) White/Albacore (soy oil) Yellowfin Albacore Skipjack Yellowfin Light White/Albacore Tuna Tuna Big-eye Yellowfin Skipjack Bluefin Tuna Albacore Tuna Tuna Tuna Tuna Tuna Tuna Tuna Tuna Tuna
8 16 7 11 5 123 45 20 22 18 551 451 399 347 29 10 15
0.095 0.260 (0.249) 0.090 (0.052) 0.085 (0.037) 0.047 (0.046) 0.407 (0.368) 0.118 (0.087) 0.10 0.31 0.05 0.128 (0.078) 0.350 (0.338) 0.383 0.118 0.285 0.502 0.264 0.183 0.340 0.054 0.230 0.220 0.33 0.263 0.163 0.114 0.143 0.280 0.125 0.117 0.649 0.278 0.274 1.326 0.41 0.130 0.30 0.29 1.23 0.45 0.31 0.174 0.222 0.14 0.190
0.037–0.178 0.193–0.384 0.036–0.174 0.020–0.587 0.025–0.069 0.997 (max.) 0.447 (max.) 0.02–0.31 0.01–0.51 0.01–0.25
Food Additives & Contaminants: Part B: Surveillance Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tfab20
Total mercury in canned tuna sold in Canada in 2006 a
a
a
Robert W. Dabeka , Arthur D. Mckenzie & Donald S. Forsyth a
Food Research Division, Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada K1A 0L2 Accepted author version posted online: 11 Nov 2013.Published online: 03 Jan 2014.
Click for updates To cite this article: Robert W. Dabeka, Arthur D. Mckenzie & Donald S. Forsyth (2014) Total mercury in canned tuna sold in Canada in 2006, Food Additives & Contaminants: Part B: Surveillance, 7:2, 110-114, DOI: 10.1080/19393210.2013.856036 To link to this article: http://dx.doi.org/10.1080/19393210.2013.856036
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Food Additives & Contaminants: Part B, 2014 Vol. 7, No. 2, 110–114, http://dx.doi.org/10.1080/19393210.2013.856036
Total mercury in canned tuna sold in Canada in 2006 Robert W. Dabeka*, Arthur D. Mckenzie and Donald S. Forsyth Food Research Division, Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada K1A 0L2
Downloaded by [National Sun Yat-Sen University] at 15:35 31 December 2014
(Received 12 September 2013; accepted 13 October 2013) Total mercury was measured in 156 composites prepared from 936 samples of canned tuna sold in Canada in 2006. Each composite comprised a single brand. Yellowfin tuna contained the lowest concentrations, averaging 0.066 mg/kg. Skipjack tuna contained slightly higher concentrations, averaging 0.132 mg/kg. The highest average concentration was found in the Albacore tuna: mean 0.325 mg/kg, range 0.174–0.507 mg/kg. The second highest concentration among the 49 albacore composites was 0.469 mg/kg. There were 72 composites for which the type of tuna was not specified. The mercury in these averaged 0.095 mg/kg and ranged from 0.016 to 0.237 mg/kg. Keywords: mercury; canned tuna; survey levels
Introduction Mercury is a nerve toxicant (Health Canada 2007) and most dietary mercury in Canada results from fish consumption (Dabeka et al. 2003). Thus, targeted monitoring of fish is necessary for developing regulations and guidelines and setting fish consumption recommendations (EPA 2007; Health Canada 2007). Tuna is a predatory fish which is known to accumulate mercury. In Canada, consumption of tuna is greater than that of any other fish, with over 40,000 metric tonnes consumed in 2004 (Health Canada 2007). Tuna is overwhelmingly sold as canned, and retail sales of canned tuna in the year 2007 were $156 million Canadian dollars, 48% of all canned seafood sales (AAFC 2007). As a result of its high consumption, canned tuna has been analysed for mercury in Canada (Dabeka et al. 2004), the United States of America (Zook et al. 1976; Shim et al. 2004; Ikem & Egiebor 2005; Burger & Gochfeld 2006; Gerstenberger et al. 2010; Groth 2010; FDA 2013) and other countries (Cugurra & Maura 1976; Acra et al. 1981; Kyle & Ghani 1983; Voegborlo et al. 1999; Velasco-Gonzalez et al. 2001; Knowles et al. 2003; Dhindsa 2004; Emami Khansari et al. 2005; Waqar 2006; Chung et al. 2008; Rahimi et al. 2010; Storelli et al. 2010; Martorell et al. 2011; Miklavcic et al. 2011; Mol 2011; Park et al. 2011; Salaramoli et al. 2012). Survey results for even the same species of tuna have varied considerably. For example, reports of average mercury concentrations in canned albacore (often labelled as “white”) tuna have ranged from a low of 0.130 mg/kg in Korea (Park et al. 2011) to highs of 0.407 mg/kg (Burger & Gochfeld 2006) and *Corresponding author. Email: [email protected] © Copyright of the Crown in Canada 2014 Health Canada
0.502 mg/kg (Gerstenberger et al. 2010) found in the United States of America. Such wide variations in levels suggest the importance of each country conducting its own survey of mercury in canned tuna available for sale domestically. While a previous Canadian survey of mercury in predatory fish had been conducted (Dabeka et al. 2004), it only included 39 canned tuna samples. To update these data and obtain a more valid estimate of mercury intake from consumption of canned tuna, a survey of total mercury in 156 composites prepared from 936 samples of canned tuna sold in Canada was conducted in 2006 and the results are presented here. Experimental Sampling A pre-market survey and retail data provided by Nielsen Marketing Inc. (Markham, Ontario, Canada) were used to determine the products available for sale in Canada as well as the amount of the individual products purchased by consumers. The Bureau of Biostatistics and Computer Applications (Health Canada, Ottawa, Canada) designed a sampling plan. Under a contract to Noraxx Inspections Inc. (Mississauga, Ontario, Canada), 936 samples in total were purchased from 16 stores in Toronto and Vancouver. Tuna samples were opened, drained, composited into 156 composites and homogenised at the Health Products and Food Branch Food Laboratory in Longueuil, PQ, Canada. Each composite contained six cans of tuna of same brand with between one and six different lot numbers within the same composite, depending on availability. Sixteen different brands were represented.
Food Additives & Contaminants: Part B Total mercury analyses
Downloaded by [National Sun Yat-Sen University] at 15:35 31 December 2014
Analyses were performed using the reagents, instrumentation and methodology described previously (Dabeka et al. 2002). After a low-temperature nitric/hydrochloric acid and hydrogen peroxide digestion, measurements were made using a CETAC-6000A dedicated mercury analyser equipped with CETAC ASX-500 autosampler and ADX auto-dilutor (CETAC, Omaha, NE, USA). The stock standard (1000 mg/kg) was purchased from SCP Science Inc. (Baie d’Urfe, Quebec, Canada). Each sample was analysed only once. Results are reported on a fresh weight basis.
Method validation Quality control measures for each analytical batch included three blanks, two blank spikes, one sample spike (in duplicate for both the unspiked and spiked sample) and duplicates of two different standard reference materials (SRMs) with certified mercury concentrations (SRM 1566b Oyster tissue from the US National Institute of Standards and Technology (NIST, Gaithersburg, MD, USA) and Dorm-2 dogfish muscle from the National Research Council of Canada (NRC, Ottawa, Ontario, Canada)). A cross-check (X-check) standard from a different manufacturer (SPEX CertiPrep Inc., Metuchen, NJ, USA) was included in each batch for standard verification during the run. The limit of detection (LOD) for the solutions was calculated for each analytical batch by multiplying the standard deviation of three reagent blanks by three. Sample LODs were calculated by multiplying the solution LOD by the dilution volume of 50 mL and dividing by the weight of the actual sample taken for analysis.
Results and discussion Method validation Quality control results are presented in Table 1, which are satisfactory except for a higher concentration found for the
111
NIST Oyster Tissue SRM. All sample concentrations were above the sample LOD, which for the average sample weight of 1.56 g was 0.89 ng/g averaged over all batches, and ranged from 0.12 to 2.8 ng/g. The precision between duplicate samples averaged 3.0% relative standard deviation (RSD). The precision for duplicate measurements of the high-concentration Dorm-2 SRM averaged 2.35% RSD, varying from 0.16% to 3.7% RSD, and that of the low-concentration Oyster tissue SRM averaged 4.08% RSD, varying from 1.1% to 14% RSD. The precision for the unspiked duplicate canned tuna samples averaged 2.53% RSD at an average concentration of 0.090 mg/kg.
Mercury levels in canned tuna samples Canned tuna mercury concentrations were highest in albacore tuna, averaging 0.326 mg/kg and ranging 0.174– 0.507 mg/kg (Table 2). The levels are slightly higher than those found previously in Canada: mean 0.260 mg/ kg, range 0.193–0.384 mg/kg (Table 3). Both the current and previous mean levels agreed well with USA means of 0.31 mg/kg (Burger & Gochfeld 2006), 0.35 mg/kg (FDA 2013) and 0.383 mg/kg (Groth 2010), as well as with means of 0.280 mg/kg in Iran (Salaramoli et al. 2012) and 0.263 mg/kg in Hong Kong (Chung et al. 2008). All of the above results were considerably higher than the average of 0.130 mg/kg reported for 66 albacore samples in Korea (Park et al. 2011). Of the different species, canned yellowfin tuna contained the lowest concentrations of mercury, averaging 0.066 mg/kg and ranging 0.046–0.095 mg/kg (Table 2). This average was lower than that of 0.085 mg/kg found previously in Canada (Dabeka et al. 2004) (Table 3). However, the previous value could have been skewed upward by one sample, likely mislabelled, containing 0.587 mg/kg. Evidence for this was the median concentration of 0.037 mg/kg for the whole data set (Table 3). Average concentrations reported elsewhere for yellowfin tuna were higher than those observed in Canadian studies, examples being 0.33 mg/kg in the USA (Zook et al.
Table 1. Quality control data. Series number 1 2 3 4 5 6 Mean Certified:
Avg. blank, ng/mL
Avg. blank std. dev. ng/mL
Solution LOD, ng/mL
Avg. blank spike, % recovery
Avg. sample spike, % recovery
SRM NIST 1566b Oyster tissue, mg/kg
SRM NRC Dorm-2, mg/kg
X-check, ng/mL
0.202 0.137 0.198 0.087 0.110 0.173 0.151
0.002 0.006 0.010 0.004 0.029 0.006 0.010
0.004 0.017 0.03 0.012 0.086 0.018 0.028
104 96 103 97 99 98 99
89 96 101 88 88 90 92
0.061 0.052 0.044 0.065 0.052 0.071 0.058 ± 0.010 0.037 ± 0.002
4.76 4.91 4.7 4.58 3.73 4.19 4.48 ± 0.44 4.64 ± 0.26
0.92 0.96 1.02 0.87 0.88 1.0 0.94
112
R.W. Dabeka et al.
Table 2. Summary of total mercury levels (mg/kg) in canned tuna. Species Albacore Skipjack Yellowfin Not specified All
N
Mean
Median
Minimum
Maximum
49 21 14 72 156
0.326 0.132 0.066 0.095 0.170
0.302 0.126 0.063 0.085 0.125
0.174 0.057 0.046 0.016 0.016
0.507 0.305 0.095 0.237 0.507
Downloaded by [National Sun Yat-Sen University] at 15:35 31 December 2014
Table 3. Literature data on mercury levels in canned tuna. Country, reference Australia (Dhindsa 2004) Canada (Dabeka et al. 2004)
USA (Burger & Gochfeld 2004) USA (Burger & Gochfeld 2006) USA (FDA 2013) USA (Groth 2010) USA (Ikem & Egiebor 2005) USA (Gerstenberger et al. 2010) USA (Shim et al. 2004) (N = 240 in total)
USA (Zook et al. 1976) Hong Kong (Chung et al. 2008) Iran (Salaramoli et al. 2012) Iran (Rahimi et al. 2010) Iran (Emami Khansari et al. 2005) Italy (Cugurra & Maura 1976)
Italy (Storelli et al. 2010) Korea (Park et al. 2011) Lebanon (Acra et al. 1981) Libya (Voegborlo et al. 1999) Mexico (Velasco-González et al. 2001) New Guinea (Kyle & Ghani 1983) Saudi Arabia (Waqar 2006) Slovenia (Miklavčič et al. 2011) Spain (Martorell et al. 2011) Turkey (Mol 2011) UK (Knowles et al. 2003)
Canned tuna species
N
Average (median) mg/kg
Range, mg/kg
Tuna Albacore Skipjack Yellowfin Other White/Albacore Light Light White/Albacore Gourmet Light Albacore Albacore Light Tuna White/Albacore Light Light (veg. oil) Light (soy oil) Light (water) White/Albacore (water) White/Albacore (soy oil) Yellowfin Albacore Skipjack Yellowfin Light White/Albacore Tuna Tuna Big-eye Yellowfin Skipjack Bluefin Tuna Albacore Tuna Tuna Tuna Tuna Tuna Tuna Tuna Tuna Tuna
8 16 7 11 5 123 45 20 22 18 551 451 399 347 29 10 15
0.095 0.260 (0.249) 0.090 (0.052) 0.085 (0.037) 0.047 (0.046) 0.407 (0.368) 0.118 (0.087) 0.10 0.31 0.05 0.128 (0.078) 0.350 (0.338) 0.383 0.118 0.285 0.502 0.264 0.183 0.340 0.054 0.230 0.220 0.33 0.263 0.163 0.114 0.143 0.280 0.125 0.117 0.649 0.278 0.274 1.326 0.41 0.130 0.30 0.29 1.23 0.45 0.31 0.174 0.222 0.14 0.190
0.037–0.178 0.193–0.384 0.036–0.174 0.020–0.587 0.025–0.069 0.997 (max.) 0.447 (max.) 0.02–0.31 0.01–0.51 0.01–0.25
