Environ Monit Assess (2014) 186:2185–2194 DOI 10.1007/s10661-013-3528-1
Risk assessment of trace elements in cultured freshwater fishes from Jiangxi province, China Li Zhang & Dawen Zhang & Yihua Wei & Linguan Luo & Tingcan Dai
Received: 14 June 2013 / Accepted: 6 November 2013 / Published online: 21 November 2013 # Springer Science+Business Media Dordrecht 2013
Abstract The levels of trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Se, and Zn) in eight species of cultured freshwater fishes from Jiangxi province were determined by inductively coupled plasma-mass spectroscopy. All the studied trace element levels in fish muscles from Jiangxi province did not exceed Chinese national standard and European Union standard, and they were often lower than previous studies. The calculated target hazard quotient values for all the studied trace elements in fish samples were much less than 1, suggesting that the studied trace elements in fish muscles from Jiangxi province had not pose obvious health hazards to consumers. As and Cd concentrations in northern snakehead were much higher than that in other fishes, demonstrating that this fish species could be valuable as a bioindicator of As and Cd in environmental surveys. In addition, the highest concentrations of Fe, Zn, and moderate contents of other essential trace elements in crucian carp indicated that crucian carp could be a good nutrient source of essential trace elements for human health. Keywords Trace elements . Fish . Risk assessment . THQ . Jiangxi province
L. Zhang : D. Zhang (*) : Y. Wei : L. Luo (*) : T. Dai Institute for Quality & Safety and Standards of Agricultural Products Research, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, People’s Republic of China e-mail: [email protected] e-mail: [email protected]
Introduction Fish are an important source of minerals, high-quality protein, and are rich of omega-3 fatty acids, which can reduce cholesterol levels and keep human hearts healthy (Daviglus et al. 2002). Due to the above benefits of fish, the worldwide fishery culture has increased tremendously in recent years. China is the biggest fish producer in the world, and the Chinese fisheries production constitutes around one third of the world total fisheries production. Additionally, China has become the world's largest exporter of fishery products since 2002. Hence, the fish product safety in China not only affects the health of Chinese people but also affects human health all over the world. Heavy metals are known to accumulate in various aquatic organisms (Yılmaz et al. 2010) and can be bioaccumulated via food chains to hazardous levels, thus posing potential risks to human health (Mathews and Fisher 2009). Therefore, there is a great need to investigate the accumulation levels of trace metals in cultured freshwater fishes in China and to estimate the health risks of trace elements to human via fish consumption. Recently, there have been extensive studies on trace element levels in wild fish from various aquatic systems (Cai et al. 2012; Rahman et al. 2012), while the studies on trace element accumulation in cultured freshwater fishes in China are scarce (Cheung et al. 2008; Jiang et al. 2005; Li et al. 2009; Liu et al. 2011; Wang et al. 2005; Yang et al. 2002), and these studies have mainly focused on the trace element accumulation in cultured fishes from the costal cities or developed cities in China.
2186
For example, the heavy metal contents in freshwater and marine fishes (primarily cultured fish) in the market of Guangzhou (Yang et al. 2002) and Shenzhen (Jiang et al. 2005) were detected and evaluated, and they found that Pb and As contents in aquatic products from Shenzhen market beyond the Chinese national standard, while the fish in Guangzhou market was safe to consume. Cheung et al. (2008) reported that a few fish species from the Pearl River Delta had average concentrations greater than the national standards for Cd and Pb established by the China National Standard Management Department. Liu et al. (2011) investigated the heavy metal contamination in four species of freshwater fish from the different farmer markets in Beijing, and they found that 80 % of fish samples meet the requirement of China national standard with 14.6 %, 5.2 %, and 10.4 % of Pb, Cd, and As excess limit values. To our knowledge, no study has been conducted to examine the accumulation levels of trace elements in cultured freshwater fish from developing areas of China. Jiangxi province lies in the southern bank of the middle and lower reaches of the Yangtze River. Jiangxi province has a superior ecological environment due to a few industry sources. It is an agricultural province and is a famous base of pollution-free, green and organic agricultural products in China. According to China Statistics Yearbook 2011, the freshwater aquaculture production in Jiangxi province ranked fourth in China (National Bureau of Statistics of China 2011). Therefore, the main goals of the present study are to (1) report the concentrations of trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Se, and Zn) in muscle of cultured freshwater fishes in Jiangxi province and (2) conduct a health risk assessment of trace elements attribute to consumption of cultured freshwater fishes from Jiangxi province.
Materials and methods Reagents All reagents used, including nitric acid (69.0 % HNO3) and hydrogen peroxide (31.0 % H2O2), were of ultra pure grade (Suzhou Crystal Clear Chemical Co., Ltd., Suzhou, China). All solutions were prepared using ultrapure water from Milli-Q water purification system (Millipore, Bedford, MA, USA). All containers, vessels, and other labwares used for storage, handling, or sample
Environ Monit Assess (2014) 186:2185–2194
decontamination were immersed overnight in 20 % HNO3 solution, rinsed with ultrapure water, and finally dried on a clean bench.
Sampling of fish Based on the Jiangxi statistical yearbook 2011, the freshwater fish productions in various cities of Jiangxi province decreased as follows: Shangrao city (366,328 tons), Jiujiang city (311,069 tons), Nanchang city (284, 974 tons), Yichun city (257,168 tons), Ganzhou city (231,099 tons), Ji'an city (168,164 tons), Fuzhou city (132,138 tons), Yingtan city (39,087 tons), Xinyu city (38,216 tons), Pingxiang city (30,595 tons), Jingdezhen city (23,971 tons) (Statistic Bureau of Jiangxi 2011). Hence, Nanchang city, Nanchang county (belonging to Nanchang city), Jiujiang city, Duchang county (belonging to Jiujiang city), Xingzi county (belonging to Jiujiang city), Shangrao city, Poyang county (belonging to Shangrao city), Fuzhou city, Yichun city, Ji'an city, and Ganzhou city were chosen as sampling sites in the present study (Fig. 1). The fish samples were collected from the largest fishery market in each sampling site during the period of April to June 2011, two samples for each fish species. Specimens were collected from the following species: white Bream (Parabramis pekinensis), grass carp (Ctenopharyngodon idellus), mandarin fish (Siniperca chuatsi), crucian carp (Carassius auratus), silver carp (Hypophthalmichthys molitrix), catfish (Silurus asotus), northern snakehead (Ophiocephalus argus), and bighead carp (Aristichthys nobilis). The body length, total length, and body weight of above fishes were demonstrated in Table 1. The collected fish were measured, weighted, and killed immediately, and then the muscle of the fish was dissected, and samples were carefully stored into clean plastic vessels, kept in cold storage, and transferred to the laboratory using ice box. In the laboratory, the fish muscle samples were frozen at −80 °C and were lyophilized using a FD-1A-50 Freeze dryer (Beijing Boyikang Lab Instrument Co, Ltd., Beijing, China). Lyophilized samples were homogenized and stored in a desiccator before trace elements were analyzed. Standards solutions for atomic spectroscopy (PerkinElmer Life and Analytical Sciences, Boston, MA, USA) were prepared from a 10 mg/L standard by dilution with acidified ultrapure water (5 % HNO3 w/w).
Environ Monit Assess (2014) 186:2185–2194
2187
50
40
30
20
10
80
90
100
110
120
130
30
Jiujiang city Xingzi county Duchang county Poyang county
29.5
29
Nanchang city Nanchang county
Shangrao city
28.5
28
Fuzhou city
Yichun city
27.5
Ji'an city 27
26.5
26
Ganzhou city
25.5
25
24.5 114
114.5
115
115.5
116
116.5
117
117.5
118
Sampling sites Fig. 1 Map of Jiangxi province showing the sampling sites
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Environ Monit Assess (2014) 186:2185–2194
Table 1 Sample information of the cultured freshwater fish collected from Jiangxi province, China Common name
Scientific name
Body length (cm)
Total length (cm)
Body weight(g)
White bream
Parabramis pekinensis
26.6(22.0–30.0)
32.5(27.0–36.5)
489.3(310.3–650.3)
18
Grass carp
Ctenopharyngodon idellus
38.1(31.0–43.0)
45.7(36.5–52.5)
1128.1(595.0–1,751.9)
22
Mandarin fish
Siniperca chuatsi
23.3(20.5–26.5)
27.9(34.5–31.5)
369.0(216.4–601.0)
16
Crucian carp
Carassius auratus
22.5(19.8–27.0)
27.9(23.8–33.0)
368.3(220.1–679.6)
22
Silver carp
Hypophthalmichthys molitrix
42.5(35.0–49.0)
52.0(42.0–60.0)
1,622.3(902.0–2,625.5)
20
Catfish
Silurus asotus
36.7(29.5–42.0)
40.3(32.5–45.5)
541.7(276.8–837.2)
17
Northern snakehead
Ophiocephalus argus
28.8(22.0–36.5)
34.1(30.5–42.0)
466.6(340.2–893.5)
14
Bighead carp
Aristichthys nobilis
36.6(25.5–41.0)
45.8(32.0–51.0)
1,163.4(461.5–1657.1)
22
Analysis The freeze-dried fish muscle samples (0.5 g) were placed into a 50 ml polytetrafluoroethylene (PTFE) microwave vessels, and 4 mL HNO3 was added. The PTFE vessels were allowed to stand overnight, and then 5 mL H2O2 were added. After 30 min, the samples containing HNO3 and H2O2 were digested in a Mars X-press Microwave Digestion System (CEM, Matthews, NC, USA) equipped with a carousel holding 40 digestion vessels. The microwave digestion process was as follows: the digested samples were heated to 120 °C within 6 min, holding 3 min, and then heated to 150 °C for 4 min, holding 3 min, and finally to 180 °C within 4 min, holding 30 min. After cooling, the clear solution was diluted to 50 mL with ultrapure water. Each sample was digested in triplicate. Trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Se, Zn) in fish muscle samples were directly analyzed using a Perkin- Elmer SCIEX Elan 9000 inductively coupled plasma-mass spectroscopy (ICP-MS; Model Elan DRC-e; PerkinElmer-SCIEX, Norwalk, CT, USA) equipped with a cross-flow nebulizer (Meinhard Associates, Golden, USA), a Scott-type spray chamber (Glass Expansion, Inc., West Melbourne, Australia), and an AS-93 Plus autosampler (PerkinElmer, Norwalk, CT, USA). Method validation and quality control of the samples were performed using standard reference materials. Quality control was assured through the analysis of triplicate samples, three reagent blanks, and procedural blanks. In addition, certified reference materials for the chemical composition of biological samples (GBW10018) from the Institute of Geophysical and Geochemical Exploration CAGS (Beijing, China) were
Number
analyzed according to the same procedures adopted for the fish samples, and the results were presented in Table 2. Blanks were below the detection limit, and the relative standard deviations for replicated sample analyses were
Risk assessment of trace elements in cultured freshwater fishes from Jiangxi province, China Li Zhang & Dawen Zhang & Yihua Wei & Linguan Luo & Tingcan Dai
Received: 14 June 2013 / Accepted: 6 November 2013 / Published online: 21 November 2013 # Springer Science+Business Media Dordrecht 2013
Abstract The levels of trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Se, and Zn) in eight species of cultured freshwater fishes from Jiangxi province were determined by inductively coupled plasma-mass spectroscopy. All the studied trace element levels in fish muscles from Jiangxi province did not exceed Chinese national standard and European Union standard, and they were often lower than previous studies. The calculated target hazard quotient values for all the studied trace elements in fish samples were much less than 1, suggesting that the studied trace elements in fish muscles from Jiangxi province had not pose obvious health hazards to consumers. As and Cd concentrations in northern snakehead were much higher than that in other fishes, demonstrating that this fish species could be valuable as a bioindicator of As and Cd in environmental surveys. In addition, the highest concentrations of Fe, Zn, and moderate contents of other essential trace elements in crucian carp indicated that crucian carp could be a good nutrient source of essential trace elements for human health. Keywords Trace elements . Fish . Risk assessment . THQ . Jiangxi province
L. Zhang : D. Zhang (*) : Y. Wei : L. Luo (*) : T. Dai Institute for Quality & Safety and Standards of Agricultural Products Research, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, People’s Republic of China e-mail: [email protected] e-mail: [email protected]
Introduction Fish are an important source of minerals, high-quality protein, and are rich of omega-3 fatty acids, which can reduce cholesterol levels and keep human hearts healthy (Daviglus et al. 2002). Due to the above benefits of fish, the worldwide fishery culture has increased tremendously in recent years. China is the biggest fish producer in the world, and the Chinese fisheries production constitutes around one third of the world total fisheries production. Additionally, China has become the world's largest exporter of fishery products since 2002. Hence, the fish product safety in China not only affects the health of Chinese people but also affects human health all over the world. Heavy metals are known to accumulate in various aquatic organisms (Yılmaz et al. 2010) and can be bioaccumulated via food chains to hazardous levels, thus posing potential risks to human health (Mathews and Fisher 2009). Therefore, there is a great need to investigate the accumulation levels of trace metals in cultured freshwater fishes in China and to estimate the health risks of trace elements to human via fish consumption. Recently, there have been extensive studies on trace element levels in wild fish from various aquatic systems (Cai et al. 2012; Rahman et al. 2012), while the studies on trace element accumulation in cultured freshwater fishes in China are scarce (Cheung et al. 2008; Jiang et al. 2005; Li et al. 2009; Liu et al. 2011; Wang et al. 2005; Yang et al. 2002), and these studies have mainly focused on the trace element accumulation in cultured fishes from the costal cities or developed cities in China.
2186
For example, the heavy metal contents in freshwater and marine fishes (primarily cultured fish) in the market of Guangzhou (Yang et al. 2002) and Shenzhen (Jiang et al. 2005) were detected and evaluated, and they found that Pb and As contents in aquatic products from Shenzhen market beyond the Chinese national standard, while the fish in Guangzhou market was safe to consume. Cheung et al. (2008) reported that a few fish species from the Pearl River Delta had average concentrations greater than the national standards for Cd and Pb established by the China National Standard Management Department. Liu et al. (2011) investigated the heavy metal contamination in four species of freshwater fish from the different farmer markets in Beijing, and they found that 80 % of fish samples meet the requirement of China national standard with 14.6 %, 5.2 %, and 10.4 % of Pb, Cd, and As excess limit values. To our knowledge, no study has been conducted to examine the accumulation levels of trace elements in cultured freshwater fish from developing areas of China. Jiangxi province lies in the southern bank of the middle and lower reaches of the Yangtze River. Jiangxi province has a superior ecological environment due to a few industry sources. It is an agricultural province and is a famous base of pollution-free, green and organic agricultural products in China. According to China Statistics Yearbook 2011, the freshwater aquaculture production in Jiangxi province ranked fourth in China (National Bureau of Statistics of China 2011). Therefore, the main goals of the present study are to (1) report the concentrations of trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Se, and Zn) in muscle of cultured freshwater fishes in Jiangxi province and (2) conduct a health risk assessment of trace elements attribute to consumption of cultured freshwater fishes from Jiangxi province.
Materials and methods Reagents All reagents used, including nitric acid (69.0 % HNO3) and hydrogen peroxide (31.0 % H2O2), were of ultra pure grade (Suzhou Crystal Clear Chemical Co., Ltd., Suzhou, China). All solutions were prepared using ultrapure water from Milli-Q water purification system (Millipore, Bedford, MA, USA). All containers, vessels, and other labwares used for storage, handling, or sample
Environ Monit Assess (2014) 186:2185–2194
decontamination were immersed overnight in 20 % HNO3 solution, rinsed with ultrapure water, and finally dried on a clean bench.
Sampling of fish Based on the Jiangxi statistical yearbook 2011, the freshwater fish productions in various cities of Jiangxi province decreased as follows: Shangrao city (366,328 tons), Jiujiang city (311,069 tons), Nanchang city (284, 974 tons), Yichun city (257,168 tons), Ganzhou city (231,099 tons), Ji'an city (168,164 tons), Fuzhou city (132,138 tons), Yingtan city (39,087 tons), Xinyu city (38,216 tons), Pingxiang city (30,595 tons), Jingdezhen city (23,971 tons) (Statistic Bureau of Jiangxi 2011). Hence, Nanchang city, Nanchang county (belonging to Nanchang city), Jiujiang city, Duchang county (belonging to Jiujiang city), Xingzi county (belonging to Jiujiang city), Shangrao city, Poyang county (belonging to Shangrao city), Fuzhou city, Yichun city, Ji'an city, and Ganzhou city were chosen as sampling sites in the present study (Fig. 1). The fish samples were collected from the largest fishery market in each sampling site during the period of April to June 2011, two samples for each fish species. Specimens were collected from the following species: white Bream (Parabramis pekinensis), grass carp (Ctenopharyngodon idellus), mandarin fish (Siniperca chuatsi), crucian carp (Carassius auratus), silver carp (Hypophthalmichthys molitrix), catfish (Silurus asotus), northern snakehead (Ophiocephalus argus), and bighead carp (Aristichthys nobilis). The body length, total length, and body weight of above fishes were demonstrated in Table 1. The collected fish were measured, weighted, and killed immediately, and then the muscle of the fish was dissected, and samples were carefully stored into clean plastic vessels, kept in cold storage, and transferred to the laboratory using ice box. In the laboratory, the fish muscle samples were frozen at −80 °C and were lyophilized using a FD-1A-50 Freeze dryer (Beijing Boyikang Lab Instrument Co, Ltd., Beijing, China). Lyophilized samples were homogenized and stored in a desiccator before trace elements were analyzed. Standards solutions for atomic spectroscopy (PerkinElmer Life and Analytical Sciences, Boston, MA, USA) were prepared from a 10 mg/L standard by dilution with acidified ultrapure water (5 % HNO3 w/w).
Environ Monit Assess (2014) 186:2185–2194
2187
50
40
30
20
10
80
90
100
110
120
130
30
Jiujiang city Xingzi county Duchang county Poyang county
29.5
29
Nanchang city Nanchang county
Shangrao city
28.5
28
Fuzhou city
Yichun city
27.5
Ji'an city 27
26.5
26
Ganzhou city
25.5
25
24.5 114
114.5
115
115.5
116
116.5
117
117.5
118
Sampling sites Fig. 1 Map of Jiangxi province showing the sampling sites
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Environ Monit Assess (2014) 186:2185–2194
Table 1 Sample information of the cultured freshwater fish collected from Jiangxi province, China Common name
Scientific name
Body length (cm)
Total length (cm)
Body weight(g)
White bream
Parabramis pekinensis
26.6(22.0–30.0)
32.5(27.0–36.5)
489.3(310.3–650.3)
18
Grass carp
Ctenopharyngodon idellus
38.1(31.0–43.0)
45.7(36.5–52.5)
1128.1(595.0–1,751.9)
22
Mandarin fish
Siniperca chuatsi
23.3(20.5–26.5)
27.9(34.5–31.5)
369.0(216.4–601.0)
16
Crucian carp
Carassius auratus
22.5(19.8–27.0)
27.9(23.8–33.0)
368.3(220.1–679.6)
22
Silver carp
Hypophthalmichthys molitrix
42.5(35.0–49.0)
52.0(42.0–60.0)
1,622.3(902.0–2,625.5)
20
Catfish
Silurus asotus
36.7(29.5–42.0)
40.3(32.5–45.5)
541.7(276.8–837.2)
17
Northern snakehead
Ophiocephalus argus
28.8(22.0–36.5)
34.1(30.5–42.0)
466.6(340.2–893.5)
14
Bighead carp
Aristichthys nobilis
36.6(25.5–41.0)
45.8(32.0–51.0)
1,163.4(461.5–1657.1)
22
Analysis The freeze-dried fish muscle samples (0.5 g) were placed into a 50 ml polytetrafluoroethylene (PTFE) microwave vessels, and 4 mL HNO3 was added. The PTFE vessels were allowed to stand overnight, and then 5 mL H2O2 were added. After 30 min, the samples containing HNO3 and H2O2 were digested in a Mars X-press Microwave Digestion System (CEM, Matthews, NC, USA) equipped with a carousel holding 40 digestion vessels. The microwave digestion process was as follows: the digested samples were heated to 120 °C within 6 min, holding 3 min, and then heated to 150 °C for 4 min, holding 3 min, and finally to 180 °C within 4 min, holding 30 min. After cooling, the clear solution was diluted to 50 mL with ultrapure water. Each sample was digested in triplicate. Trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Se, Zn) in fish muscle samples were directly analyzed using a Perkin- Elmer SCIEX Elan 9000 inductively coupled plasma-mass spectroscopy (ICP-MS; Model Elan DRC-e; PerkinElmer-SCIEX, Norwalk, CT, USA) equipped with a cross-flow nebulizer (Meinhard Associates, Golden, USA), a Scott-type spray chamber (Glass Expansion, Inc., West Melbourne, Australia), and an AS-93 Plus autosampler (PerkinElmer, Norwalk, CT, USA). Method validation and quality control of the samples were performed using standard reference materials. Quality control was assured through the analysis of triplicate samples, three reagent blanks, and procedural blanks. In addition, certified reference materials for the chemical composition of biological samples (GBW10018) from the Institute of Geophysical and Geochemical Exploration CAGS (Beijing, China) were
Number
analyzed according to the same procedures adopted for the fish samples, and the results were presented in Table 2. Blanks were below the detection limit, and the relative standard deviations for replicated sample analyses were
