Evaluation of copper, lead and arsenic level in tilapia ...

Biologia 68/5: 983—991, 2013 Section Zoology DOI: 10.2478/s11756-013-0241-z

Evaluation of copper, lead and arsenic level in tilapia fish in Cempaka Lake (Bangi, Malaysia) and human daily/weekly intake Abdulali Taweel, Mohammad Shuhaimi-Othman & Abas Kutty Ahmad School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, University Kebangsaan Malaysia, Bangi, 43600, Selangor; e-mail: [email protected]

Abstract: In recent years, many studies have stated the nutritional benefits of fish consumption: vitamins, proteins and omega-3 fatty acids, which may protect humans from adverse health effects, including heart disease and stroke. This study aimed to evaluate the concentration of Cu, Pb and As in the liver, gills and muscles of tilapia fish (Oreochromis niloticus) and to calculate the weekly intake from eating tilapia collected from Cempaka Lake, Selangor – Peninsular Malaysia during the period between April 2009 to February 2010. The elemental concentrations were determined using inductively – coupled plasma mass spectrometry (ICP-MS). The results showed that all heavy metal concentrations were significantly different among fish organs, and between calendar months. The data showed that Cu levels in liver, gills and muscles were 491.30, 3.70 and 1.82 µg/g dry weight (dw), respectively. Meanwhile Pb levels were 2.71, 1.04 and 0.48 µg/g dw, respectively and As levels were 6.26, 4.18 and 1.79 µg/g dw, respectively. Significant changes occurred in Cu, Pb and As levels in tilapia fish organs in Cempaka Lake over the period of 11 months. Tilapia weekly intake was calculated based on mean Cu, Pb and As concentrations in the muscle of tilapia fish and adult consumption of tilapia in Malaysia which averages at 160 grams per day. Furthermore, tilapia weekly and daily human intakes for Cu, Pb and As were compared with the Provisional Tolerable Weekly Intake (PTWI) established by the JECFA (WHO/FAO) presenting values below the PTWI. Metal levels in fish muscle were found to be lower than the maximum permitted concentrations recommended by various authorities; hence, consumption of tilapia fish from Cempaka Lake is currently safe for humans. Key words: heavy metals; lake; Provisional Tolerable Weekly Intake; tilapia consumption

Introduction Many studies have shown that human activities have caused environmental pressure on the natural habitat of fish and other aquatic organisms throughout time. There is ongoing concern with pollution of the aquatic system as a result of this deleterious effect. Although metals occur naturally in aquatic ecosystems, high population growth accompanied with intensive urbanization, industrial activities and higher exploitation of natural resources has increased pollution levels (Olowu et al. 2010). In industrial regions of the world the disposing of heavy metals such as arsenic, cadmium, copper, lead and mercury has been given significant concern because of their rising levels in the aquatic environments (Bako & Daudu 2007), and because of their adverse effects on aquatic life forms (Lopa & Adhikari 2006). Lake ecosystems are vulnerable to heavy metal pollution due to toxic discharges from the surrounding environment. Fish are affected by toxic, metal-polluted water, which originates from several sources such as chemical waste, periodic rainwater contaminated with atmospheric pollutants, discharge of manufacturing or sewerage effluents, agricultural drainage and domestic sewage (Rashed 2001). However, most pollutants found in aquatic organisms accumulate through the

food chain. First, small organisms such as phytoplankton, bacteria, fungi and others absorb heavy metals and in turn eaten by fish (Benson et al. 2006). Fish often accumulate a great amount of some heavy metals from the surrounding water and are at the top of the aquatic food chain. Fish constitute an important source of protein for humans (Kamaruzzaman et al. 2010), particularly in developing countries, where fish meat is known to be an established health food for most people, in contrast to meat and poultry (Nor Hasyimah et al. 2011). Fish liver is often recommended as an environmental indicator of water pollution, a fact attributed to the tendency of the liver to accumulate pollutants of various kinds at higher levels than their environment (Al-Yousuf et al. 2000). Fish are an important part of the human diet and easily accumulate metals from the water via bioconcentration and biomagnification (Lin et al. 2004). Even though Fish consumption is a main route of chemical exposure for people, fish are known to bring nutritional benefits to humans. Fish is known as an excellent source of protein and contains omega 3fatty acids that help decrease the risk of certain kinds of cancer and heart disease (Dougherty et al. 2000; Ikem et al. 2003; La Vecchia et al. 2001; Terry et al. 2001). Heavy metals like copper, zinc and iron are essential for fish metabolism and physiology whereas some oth-

Unauthenticated c 2013 Institute of Zoology, Slovak Academy of Sciences

Download Date | 9/25/15 1:59 AM

984

A. Taweel et al.

Fig. 1. The location of the sampling site of tilapia fish in Cempaka Lake, Bandar Baru Bangi town, Selangor, Peninsular Malaysia.

ers such as mercury, cadmium and lead have no known function in biological systems (Canli & Atli 2003). Contamination of aquatic environments (e.g., lakes, rivers, etc.) with heavy metals has been receiving increased global attention because of their toxicity, persistence and bio-accumulative nature (Ikem et al. 2003; Mansour & Sidky 2002). Among all pollutants, heavy metals have been observed to be the most persistent because they do not degrade and cannot be broken down by biological or natural processes (Kamaruzzaman et al. 2010). The US Food and Drug Administration indicated that fish and other seafood account for 90% of total human exposure to arsenic (As) (USFDA 1993a). The Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JCEFA) has set the Provisional Tolerable Weekly Intake (PTWI) for heavy metals such as copper (Cu), lead (Pb) and Arsenic (As). PTWI is an estimated amount of a contaminant that can be ingested by humans over a lifetime without appreciable risk. JECFA derives tolerable intakes, expressed on a daily or a weekly basis, for contaminants (WHO 1987). Many contaminants are not removed rapidly from the human body, and hence provisional tolerable weekly intakes (PTWIs) are allocated. The expression tolerable is used because it describes permissibility rather than acceptability for the intake of contaminants associated with the consumption of nutritious foods (FAO/WHO 1987). Cu, Pb and As are usually studied because of their importance in the aquatic ecosystem with respect to human consumption of fish. The primary purpose of this study was to obtain quantitative information on the concentration of heavy metals in tilapia fish, Oreochromis niloticus (L., 1758), collected from Cempaka Lake, Selangor – Peninsular Malaysia. Furthermore, the safety of human dietary intake of Cu, Pb and As from tilapia consumption was assessed.

Material and methods Study area and fish sampling Fresh water fish tilapia fish (O. niloticus) were sampled from April 2009 to February 2010 with assistance of professional fishermen at Cempaka lake, a lake located at 02◦ 57 33.37 N, 101◦ 46 34.82 E; in Bangi town, Selangor, Peninsular Malaysia, as shown in Fig. 1. Cempaka lake is one of the newest recreational parks in the region (Said et al. 2012). The lake is surrounded by a new industrial area, petrol stations and a shopping center. Eighteen fish were sampled directly from Cempaka Lake: three fish per each of the 6 sampling dates (at every other month of the 11-month study period). Total size and weight of the fish were measured; fish length ranged between 18–22 cm, and the wet weight ranged between 180–220 g. The sampled fish were mostly of a consumable size (Howaida & Ali 2007). Fish were carefully conserved in clean polyethylene bags with ice to minimize the tissue decay and to maintain moist conditions during transportation (Eastwood 2000). The fish were placed in an isolated container during transportation and immediately taken to the toxicity laboratory on the same day, washed by using deionized water, identified and then deep frozen at –20 ◦C while awaiting dissection on the following day. Preparation of samples and metal analysis The Frozen fish were thawed at room temperature and were carefully dissected to remove the liver, gills and muscles. Each studied body part, sampled in duplicate per fish, was homogenized separately and weighed. Samples were ovendried at 80 ◦C for 48 hours in Petri dishes and were taken to cool in the desiccators afterward ground into a fine powder by using a porcelain mortar and pestle. Portions of 0.5 g dry weight (dw) powdered form of gills and muscles as well as 0.1 g dw powdered form of liver in duplicate were digested using closed vessel microwave digestion (Milestone model Start D, Italy). Ultra pure nitric acid (65%) and hydrogen peroxide (35%) mixture 3:1 in ratio were used for samples digestion (Durali et al. 2010), at a temperature of 150 ◦C for 20 minutes, followed by cooling to room temperature for 35 minutes in the microwave. The samples were digested as described in previous studies (Taweel et al. 2011;

Unauthenticated Download Date | 9/25/15 1:59 AM

Heavy metal level in tilapia fish in Malaysia

985

Table 1. Measured and certified values of heavy metal concentrations (µg/g dry weight). Metals Cu Pb As

Measured value

Certified value

Recovery (%)

3.96 1.37 13.08

4.04 ± 0.33 1.19 ± 0.18 13.30 ± 1.85

99 98 98

Table 2. operational parameter settings that were used to operate the ELAN 9000 Perkin Elmer. Characteristics RF Generator RF Power Spray Chamber Nebulizer Plasma gas flow Auxiliary gas flow Nebulizer gas flow Sampler& Skimmer cone

Instruments Condition 40 MHz 1000 W Ryton Scott Cross-flow 15.0 L/min 1.0 L/min 0.60 L/min Nickel

Taghipour & Aziz 2010). The microwave digestion method was an accurate method for samples digestion compared to other methods such as dry ashing and wet digestion (Durali et al. 2010). Hydrogen peroxide decreases nitrous vapours and speeds up the digestion of organic substances by elevating the reaction temperature (Dig-Acids 2001). At the completion of digestion, the samples were filtered through 0.45 µm Whatman filter paper (Germany) into volumetric flasks and diluted to a total volume of 25 ml for liver and 50 ml for gills and muscles for elemental analysis. Heavy metals analysis was carried out by using inductively-coupled plasma mass spectrometry (ICP-MS) (model ELAN 9000 Perkin Elmer ICP-MS, USA), with operational parameter settings as indicated in Table 2. Elemental detection limits were Cu 0.0002 µg L−1 , Pb 0.00004 µg L−1 and As 0.0006 µg L−1 . Reagents All reagents were of analytical reagent grade, unless otherwise stated. Double deionised water was used for all dilutions. HNO3 (65%) and H2 O2 (30%) were of ultrapure quality (E. Merck, Darmstadt, Germany). All the plastic and glassware were cleaned by soaking in dilute HNO3 (1/9, v/v) and were rinsed with distilled water prior to use. The element standard solutions used for calibration were produced by diluting a stock solution of 1000 mg L−1 of the given element, supplied by Sigma Chemical Co. (Kasmani 2007). Quality control In order to ensure quality control, the accuracy of the method was confirmed by analyzing reference materials (SRM2976), freeze-dried mussel tissue, National Institute of Standards and Technology. Agreement was found between the certified and analyzed values, percentage recoveries for metals analyses were 98–99% as shown in Table 1. The potential presence of heavy metals with chemicals used in digestion was determined. Blanks were used simultaneously in each batch of analysis to authenticate the analytical quality.

Acceptable Daily Intake (ADI) The Acceptable Daily Intake (ADI) for humans is defined as an estimate of the amount of heavy metals that can be ingested daily over a lifetime without any risk to human health (Benford 2000; Herber et al. 2001). The ADI is used widely to describe safe levels of intake, other terms that were used are the reference dose (RfD) and tolerable intakes that are presented daily (TDI or tolerable daily intake) or used to estimate weekly intake (TWI or tolerable weekly intake) (Herrman &Younes 1999). The ADI is expressed in milligrams of the metals per kilogram of body weight. Estimated daily and weekly intake of heavy metals from tilapia fish The JECFA uses the term Estimated Daily Intake (EDI) and Provisional Tolerable Daily Intake (PTWI) for contaminants as heavy metals that can accumulate in the human body (Herrman & Younes 1999). Estimated daily intake (EDI) (µg/kg body weight) of heavy metals from tilapia fish consumption was obtained by Equation (1) (Shao et al. 2011; Song et al. 2009): EDI =

C × FIR WAB

(1)

where, C (µg/g ww) is an average weighted heavy metal content in fish edible portion (muscle), FIR (gram/day – person) is a daily fish consumption. WAB is the average body weight of 64 kg for Malaysians (Lim et al. 2000; Salwa & Shuhaimi-Othman 2011). As reported in the literature, the average FIR for Malaysian adults is 160 g of fish/dayperson (Agusa et al. 2007; FAO 2005, 2009). For comparison, the fish consumption rate in countries in the same region, Hong Kong, 164 g/day (Cheung et al. 2008), and Thailand 85 g/day. For WAB comparison, Chinese 63.9 g/day, Bangladesh is 60 g/day and Hong Kong 55.9 kg. EDI = average concentration (µg/g) × consumption rate (160 g/d) / body weight (64 kg), EWI = EDI × 7. To obtain estimated weekly intake (EWI) the EDI will be multiplied by a factor of 7 corresponding to 7 days and compare the obtained value with JECFA provisional tolerable weekly intake value (PTWI). Moreover, to calculate the Hazard quotient (HQ) = EDI/RfD (Cheung et al. 2008). Guidelines for interpreting HQ calculations are: If the ratio of HQ is < 1, there was not any hazard exists; HQ is 0.1–1.0, hazard is low; HQ is 1.1–10, hazard is moderate and finally if HQ is > 10, hazard is high (Lemly 1996). Statistical analysis Analysis of variance was performed on all experimental data, and means of heavy metals for the calendar months and fish tissues were compared using tukey’s test with SPSS (version 20) software. The significant level was P < 0.05.

Results and discussion Heavy metals concentrations in tilapia fish Analysis of heavy metals in the liver and gill is most often recommended as an environmental indicator of water pollution (Kamaruzzaman et al. 2010). Fish muscle is chosen as it is the part which is consumed by people (Agusa et al. 2005; Zauke et al. 1999), Muscle, generally, accumulates the lowest level of heavy metals (Ronagh et al. 2009). In order to compare dry weight values (present study) with wet weight values of other studies, a conversion factor of 5.88 (1/0.17) was applied (Yap et al. 2004).


986

A. Taweel et al.

Table 3. Copper (Cu), lead (Pb) and arsenic (As) concentrations (µg/g dry weight) in the liver of tilapia fish collected from Cempaka Lake, N = 18. Metal

Months

Mean

SD

Min

Max

F

P-value

Cu

April June August October December February Total

345.60 807.14 440.08 151.35 603.59 600.07 491.30

76.73 69.15 62.43 27.77 65.60 78.93 221.10

252.48 679.79 365.57 117.64 541.94 505.34 117.64

430.86 874.25 516.06 193.19 690.32 705.65 874.25

77

000

Pb


2.34 1.61 2.49 4.59 2.02 3.21 2.71

0.32 0.25 0.54 0.38 0.49 0.29 1.05

1.70 1.35 1.83 4.06 1.44 2.78 1.35

2.53 2.01 3.22 5.05 2.68 3.67 5.05

44

000

As


4.93 10.74 2.87 4.23 10.83 3.95 6.26

0.88 1.21 0.38 0.45 2.14 1.16 3.48

3.60 8.77 2.54 3.58 9.04 2.79 2.54

5.76 12.19 3.39 4.76 14.34 5.45 14.34

55

000

Explanations: P-value using One-way ANOVA was performed and means were compared using Tukey’s test with SPSS for windows (version 20) software.

Copper (Cu) Copper level in fish liver from Cempaka Lake for one year changed considerably among all months. The values among the months differed in a statistically significant manner (P < 0.05), the highest was found in fish liver collected in June 807.14 ± 69.15 µg/g dry weight (dw) as shown in Table 3, almost same result was obtained by Fevzi (2009) 749.76 µg/g dw while the lowest was in fish collected in October 151.35 ± 27.77 µg/g dw. Moreover, the Cu level in fish gills and muscles varied significantly among all months (P < 0.05). The Cu level in gills and muscle was the highest in fish collected in August 7.27 ± 2.78 and 3.40 ± 0.76 µg/g dw, respectively, whereas Cu level in gills and muscle was the lowest in fish collected in April, which were 1.41 ± 0.06 and 1.28 ± 0.05 µg/g dw, respectively (Tables 4, 5). Meanwhile, previous studies have reported Cu levels of 2.07 µg/g dw in fish muscle (Ronagh et al. 2009), 0.76 to 12.52 µg/g dw in muscle of 15 fish species from Lake Chini, Pahang, Malaysia (data converted to dry weight) (Ahmad & Shuhaimi-Othman 2010). Fevzi (2009) obtained values ranging from 7.88–32.98 µg/g dw in fish muscle (data converted to dry weight), and the average concentration of Cu in fish muscle obtained by Monday & Nsikak (2007) was 1.93 µg/g dw in muscle of the fish caught from Imo River, Nigeria. In the present study Cu values are in agreement with literature values and have not posed a threat to the health of humans. In general, Cu concentrations were comparatively higher in the liver than in the gill and muscle of tilapia fish. Lead (Pb) Among all studied organs the Pb concentration was observed in higher values in fish liver than in gills. The Pb

level in liver among all months varied significantly (P < 0.05) and ranged from 1.61 ± 0.25 µg/g dw in June to 4.59 ± 0.38 µg/g dw in August, with average 2.71 ± 1.05 µg/g dw (Table 3), this value is less than the result obtained by Shinn et al (2009) where the value 5.47 µg/g dw liver concentration was calculated for wet weight and was converted to dry weight by multiplying by a factor of 5.88 (Yap et al. 2004). The highest Pb levels in gills and muscle were in February compared with other months (2.50 and 1.94 µg/g dw, respectively), and the average was 1.04 and 0.48 µg/g dw, respectively. Previous studies have reported Pb levels of 0.61 µg/g dw in fish gills and a value of 0.44 µg/g dw in fish muscle (Hosseinkhezri & Tashkhourian 2011). Pb contents of 0.56 µg/g dw have been reported in a study conducted by Monday & Nsikak (2007) in fish muscle. The Pb concentration in all fish samples were under world health organization (WHO) limitations. Differences in concentrations of Pb in gill and muscle were statistically significant (P < 0.05). Arsenic (As) Arsenic level in all tilapia fish from Cempaka Lake for all months and fish body parts varied in a statistically significant manner (P < 0.05). The highest concentration of As was recorded in liver followed by gill, while in the edible part of the fish it was the lowest. The highest As in liver was observed in fish collected in December, 10.83 µg/g dw, followed by June 10.74 µg/g dw, while the Average liver As level in all months was 6.26 µg/g dw. On the other hand, As level in fish gill ranged from 2.67 µg/g dw in February to 5.84 µg/g dw in June with an average of 4.18 µg/g dw. The range of As in fish muscle was 1.27 µg/g dw



987

Table 4. Copper (Cu), lead (Pb) and arsenic (As) concentrations (µg/g dry weight) in the gills of tilapia fish collected from Cempaka Lake, N = 18. Metal

Months

Mean

SD

Min

Max

F

P-value

Cu


1.41 4.10 7.26 3.23 3.23 2.98 3.70

0.06 0.49 2.78 0.499 0.75 0.86 2.15

1.36 3.44 4.56 2.78 2.44 2.21 1.36

1.52 4.70 11.51 4.13 4.32 4.53 11.51

14

000

Pb


0.37 0.23 1.50 0.79 0.87 2.50 1.04

0.04 0.07 0.33 0.15 0.23 0.61 0.83

0.34 0.12 1.03 0.56 0.63 2.03 0.12

0.44 0.28 1.82 1.01 1.19 3.44 3.44

45

000

As


3.24 5.84 4.24 3.34 5.72 2.67 4.18

0.89 0.76 1.12 0.31 0.78 0.47 1.43

2.40 4.62 2.59 2.97 5.11 1.92 1.92

4.64 6.58 5.86 3.76 7.21 3.29 7.21

18

000

Explanations: P-value using One-way ANOVA was performed and means were compared using Tukey’s test with SPSS for windows (version 20) software.

Table 5. Copper (Cu), Lead (Pb) and Arsenic (As) concentrations (µg/g dry weight) in the muscle of tilapia fish collected from Cempaka Lake, N = 18. Metal

Months

Mean

SD

Min

Max

F

P-value

Official limits

Cu


1.28 1.37 3.40 2.23 1.40 1.27 1.82

0.05 0.28 0.76 0.44 0.23 0.31 0.88

1.18 1.02 2.64 1.79 1.04 0.88 0.88

1.33 1.77 4.51 2.93 1.67 1.63 4.51

26

000

150 A 30 B

Pb


0.15 0.09 0.15 0.29 0.27 1.94 0.48

0.051 0.020 0.035 0.03 0.05 0.44 0.69

0.10 0.07 0.12 0.23 0.22 1.53 0.07

0.23 0.12 0.21 0.32 0.32 2.58 2.58

94

000

10 A 2B

As


1.65 2.49 1.27 2.17 1.72 1.46 1.79

0.11 0.43 0.15 0.51 0.08 0.31 0.51

1.53 1.99 1.10 1.66 1.58 1.12 1.10

1.80 3.12 1.55 2.82 1.80 1.87 3.12

13

000

2.3 2.0

C D

Explanations: A (MFR 1985), B (WHO 1989), C (Hong Kong Government 1987) and D (ANZFA 1999). P-value using One-way ANOVA was performed and means were compared using Tukey’s test with SPSS for windows (version 20) software.

in fish collected in June to 2.49 µg/g in that collected in August, the average was 1.79 µg/g dw (Table 5), whereas Han et al. (1998) obtained As value in fish muscle which ranged from 0.13–1.45 µg/g dw. While Cheung et al. (2008) recorded As concentration in tilapia fish at range of 0.42 to 2.24 µg/g wet weight, and Kamaruzzaman et al. (2011) reported that

As level in fish gills (0.035 µg/g dw) was higher than that detected in fish muscle (0.025 µg/g dw). Concentrations of As in fish muscle in June and October demonstrated an anomalous trend, possibly due to the variation in rainfall in the study area in those months, this variation was recorded in As level in gills and liver.


988

A. Taweel et al.

Fig. 2. Average concentrations of the whole sampling season for Cu, Pb and As in liver (A), gills (B) and muscle (C) of Tilapia fish collected from Cempaka Lake. Cu (dark grey), Pb (black), and As (light grey).

The concentrations of Cu, Pb, and As in the different tilapia fish organs from Cempaka lake are shown in Tables 3, 4, and 5 and Figs 2A–C. The data show the variation of these metals throughout the 11-month sampling period. The results have revealed that heavy metals level are consistently higher in the liver than in the gills and muscle tissues, similar results were found by Kamaruzzaman et al. (2011) and Chi et al. (2007). The three studied fish parts in this investiga-

tion were chosen because the levels of heavy metals in fish liver represent storage of metals, this is possibly attributed to its tendency to accumulate pollutants, gills reflect the degree of water pollution and muscle is the most important fish part for human consumption as previously reported in literatures (Canli & Atli 2003; Karadede et al. 2004). Concentrations of metals among the studied body parts were significantly different (P < 0.05).



989

Table 6. Estimated daily and weekly intakes (EDI and EWI) of Cu, Pb and As via tilapia fish by people from Cempaka lake, Selangor Malaysia, and established limits. Metal

Cu Pb As

Average EDI ADIA EWI (µg/kg bw/w) PTWIB Ratio of EWI to PTWI RfDC HQ (µg/g dw) (µg/g bw/d) (µg/g bw/d) (µg/kg bw/w) (µg/kg bw/w) (%) (µg/kg bw/d) 1.82 0.48 *0.18

4.55 1.20 0.45

50–500 3.57 2.10

31.85 8.40 3.15

350–3500 25 15

0.91–9.1 33.61 21.43

40 2 0.3

0.11 0.60 1.50

Explanations: A Accepted daily intake which was calculated from PTWI set by JECFA (1993); B PTWI set by JECFA (1993); C Reference doses of metals were established by the US-EPA (2005); *(As) value as inorganic As; the average level of inorganic As was estimated by using 10% of total (As) accordance with USFDA (1993b).

Estimated daily intake of heavy metals from tilapia fish Compared to other countries, Malaysia is considered the second highest country in the world for the consumption of fish after Japan (Hajeb & Jinap 2011). The estimated daily and weekly intakes for tilapia fish consumed by an adult in Cempaka Lake in Selangor Malaysia were estimated on the basis of the levels of heavy metals in fish muscle and daily fish consumption. Table 6 shows the estimated weekly intake (EWI) and the estimated daily intake (EDI) values, According to the United States Food and Drug Administration (USFDA 1993b). The estimated intake of Cu, Pb and As from tilapia fish was 4.55, 1.20 and 0.45 µg/g bw/day, respectively, which was less than the JECFA provisional tolerable daily and weekly intake value (ADI and PTWI) for studied heavy metals, thus there is no potential health risk for people who have a high consumption rate. As shown in Table 6 the EWI values for Cu, Pb and As are below PTWI concentrations, the Ratio of EWI to PTWI are 1.91–9.1, 33.61 and 21.43% for Cu, Pb and As, respectively. The Hazard Quotient (HQ) values of Cu, Pb and As were 0.11, 0.60 and 1.50, respectively. Only As presented a Hazard Quotient (HQ) value of concern (moderate level of hazard; Table 6). Therefore, the present study showed that the consumption of tilapia fish from Cempaka Lake at the rate of 160 g/day/person most probably does not pose a health hazard to the local population, with the exception of As which may have a moderate hazard effect on human health. A value of 10% of total As can be used as an estimate of inorganic As. Based on this, tilapia fish muscle does not have concentrations exceeding the limits of As for human consumption. Conclusion The concentration of the studied heavy metals in the liver, gills and muscles of tilapia fish varied significantly among the organs and throughout the months. The present result shows that the consumption of tilapia fish from the study area at the rate of 160 g/day/person is not expected to pose a health risk to the local population. Muscle weekly ingestion rates do not exceed the recommended PTWI in the study area. The estimated intake of metals was less than the JECFA ADI and PTWI and therefore there is no potential health risk for people who have a high consumption rate of 160 g/person/day of tilapia fish. Studied heavy metal

level in analyzing fish samples was found to be lower than the legal limits which have been set by the local and International organizations. Tilapia fish samples should also be analysed more often for heavy metals concentration with respect to toxic elements such as As and to observe the status of the lake and to maintain the fish healthy. Acknowledgements The authors thank the School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM) for providing laboratory facilities to analyze the fish samples. The authors also are delighted to express their gratefulness and sincere thanks to the Ministry of High Education – Libya for their financial support and assistance. References Agusa T., Kunito T., Sudaryanto A., Monirith I., Kan-Atireklap S., Iwata H., Ismail A., Sanguansin J., Muchtar M., Tana T.S. & Tanabe S. 2007. Exposure assessment for trace elements from consumption of marine fish in Southeast Asia. Environ. Pollut. 145: 766–777. DOI: http://dx.doi.org/10.1016/j. envpol.2006.04.034 Agusa T., Kunito T., Yasunaga G., Iwata H., Subramanian A., Ismail A. & Tanabe S. 2005. Concentrations of trace elements in marine fish and its risk assessment in Malaysia. Mar. Pollut. Bull. 51: 896–911. DOI: http://dx.doi.org/10.1016/j. marpolbul.2005.06.007 Ahmad A.K. & Shuhaimi-Othman M. 2010. Heavy metal concentrations in sediments and fishes from Lake Chini, Pahang, Malaysia. J. Biol. Sci. 10: 93–100. DOI: 10.3923/jbs.2010.93. 100 Al-Yousuf M.H., El-Shahawi M.S. & Al-Ghais S.M. 2000. Trace metals in liver, skin and muscle of Lethrinus lentjan fish species in relation to body length and sex. Sci. Total. Environ. 256: 87–94. DOI: http://dx.doi.org/10.1016/S00489697(99)00363-0 ANZFA. 1999. Food Standards Code in the Gazette. Australia New Zealand Food Authority. Bako S.P. & Daudu P. 2007. Trace metal contents of the emergent macrophytes Polygonum sp. and Ludwigia sp. in relation to the sediments of two freshwater lake ecosystems in the Nigerian Savanna J. Fish. Aquat. Sci. 2: 63–70. DOI: 10.3923/jfas.2007.63.70 Benford D. 2000. The Acceptable Daily Intake – A tool for ensuring food safety. International Life Science Institute USA, ILSI Press, 38 pp. ISBN-10: 1578810914 Benson N.U., Etesin M.U., Essien J.P., Umoren I.U. & Umoh M.A. 2006. Tissue elemental levels in fin-fishes from Imo River System, Nigeria: Assessment of liver/muscle concentrations ratio. J. Fish. Aquat. Sci. 1: 277–283. DOI: 10.3923/jfas.2006.277.283


990

A. Taweel et al.

Canli M. & Atli G. 2003. The relationships between heavy metal (Cd, Cr, Cu, Fe, Pb, Zn) levels and the size of six Mediterranean fish species. Environ. Pollut. 121: 129–136. DOI: http://dx.doi.org/10.1016/S0269-7491(02)00194-X Cheung K.C., Leung H.M. & Wong M.H. 2008. Metal concentrations of common freshwater and marine fish from the Pearl River Delta, South China. Arch. Environ. Contam. Toxicol. 54: 705–715. DOI: 10.1007/s00244-007-9064-7 Dig-Acids. 2001. Guidelines for microwave acid digestion. http:// www.scribd.com/doc/6789831/DigAcids [Accessed 26.04. 2011]. Dougherty C.P., Holtz S.H., Reinert J.C., Panyacosit L., Axelrad D.A. & Woodruff T.J. 2000. Dietary exposures to food contaminants across the United States. Environ. Res. 84: 170– 185. DOI: 10.1006/enrs.2000.4027 ¨ ¨ Mustafa T. & Mustafa S. 2010. DetermiDurali M., Omer F.U., nation of trace metals in different fish species and sediments from the River Yesilırmak in Tokat, Turkey. Food Chem. Toxicol. 48: 1383–1392. DOI: http://dx.doi.org/10.1016/j.fct. 2010.03.006 Eastwood S. 2000. Effects of Environmental Metal Contamination on the Condition of Northeastern Ontario Yellow Perch (Perca flavescens). MSc Thesis, School of Graduate Studies Department of Biology Laurentian, University Sudbury, 87 pp. FAO 2005. Food Security Statistics. http://www.fao.org/faostat/ foodsecurity/index en.htm. [Accessed 15.08.2012] FAO 2009. Fishery and Aquaculture Statistics. ftp://ftp.fao.org/ FI/CDrom/CD yearbook 2009/navigation/ index content food balance e.htm [Accessed 15.08.2012] FAO/WHO. 1987. Principles of the Safety Assessment of Food Additives and Contaminants in Food Environmental Health Criteria, No. 70, Geneva, 174 pp. Fevzi Y. 2009. The comparison of heavy metal concentrations (Cd, Cu, Mn, Pb, and Zn) in tissues of three economically important fish (Anguilla anguilla, Mugil cephalus and Oreochromis niloticus) inhabiting K¨ oycegiz Lake-Mugla (Turkey) Turk. J. Sci. Tech. 4: 7–15. Hajeb P. & Jinap S. 2011. Mercury exposure through fish and seafood consumption in the rural and urban coastal communities of Peninsular Malaysia. World. J. Fish Mar. Sci. 3: 217–226. Han B.C., Jeng W.L., Chen R.Y., Fang G.T., Hung T.C. & Tseng R.J. 1998. Estimation of target hazard quotients and potential health risks for metals by consumption of seafood in Taiwan. Arch. Environ. Contam. Toxicol. 35: 711-720. PMID: 9776791 Herber R.F.M., Duffus J.H., Christensen J.M., Olsen E. & Park M.V. 2001. Risk assessment for occupational exposure to chemicals. A review of current methodology (IUPAC Technical Report). Pure. Appl. Chem. 73: 993–1031. DOI: http://dx.doi.org/10.1351/pac200173060993 Herrman J.L. & Younes M. 1999. Background to the ADI/TDI/ PTWI. Regul. Toxicol. Pharmacol. 30: S109–S113. DOI: http://dx.doi.org/10.1006/rtph.1999.1335 Hong Kong Government 1987. Food Adulteration (Metallic Contamination) Regulations. Laws of Hong Kong 2, Chapter 132. Hosseinkhezri P. & Tashkhourian J. 2011. Determination of heavy metals in Acanthopagrus latus (Yellowfin seabream) from the Bushehr seaport (coastal of Persian Gulf), Iran. Int. Food. Res. J. 18: 791–794. Howaida R.G. & Ali-A-F.A.G -A. 2007. Comparison of biochemical composition and organoleptic properties between wild and cultured finfish. J. Fish. Aquat. Sci. 2: 77–81. DOI: 10.3923/jfas.2007.77.81 Ikem A., Egiebor N.O. & Nyavor K. 2003. Trace elements in water, fish and sediment from Tuskegee Lake, Southeastern USA. Water. Air. Soil. Pollut. 149: 51–75. DOI: 10.1023/A:1025694315763 JECFA 1993. Evaluation of certain food additives and contaminants. Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives. World Health Organization Technical Report Series No. 837.

WHO, Geneva, Switzerland, 53 pp. http://whqlibdoc.who.int /trs/WHO TRS 837.pdf [Accessed 15.08.2012] Kamaruzzaman B., Ong M.C., Rina S.Z. & Joseph B. 2010. Levels of some heavy metals in fishes from Pahang river estuary, Pahang, Malaysia. J. Biol. Sci. 10: 157–161. DOI: 10.3923/jbs.2010.157.161 Kamaruzzaman B., Zahir M.S., John A.B, Waznah S.A, Jalal K.C.A., Shahbudm S., Al-Barwam S.M & Goddard J.S. 2010. Determination of some heavy metal concentrations in razor clam (Solen brevis) from Tanjung Lumpur coastal waters, Pahang, Malaysia. Pak. J. Biol. Sci. 13: 1208–1213. DOI: 10.3923/pjbs.2010.1208.1213 Kamaruzzaman B.Y., Rina Z., John B.A & Jalal K.C.A. . 2011. Heavy metal accumulation in commercially important fishes of south west Malaysian coast. Res. J. Environ. Sci. 5: 595– 602. DOI: 10.3923/rjes.2011.595.602 ¨ u E. 2004. Heavy metals in mulKaradede H., Oymak S.A. & Unl¨ let, Liza abu, and catfish, Silurus triostegus, from the Atat¨ urk Dam Lake (Euphrates), Turkey. Environ. Int. 30: 183–188. . DOI: http://dx.doi.org/10.1016/S0160-4120(03)00169-7 Kasmani M.E. 2007. Bioaccumulation and distribution of selected heavy metals in water, sediment,aquatic plants and fish in Tasik Chini. PhD Thesis, University Kebangsaan Malaysia, 33 pp. La Vecchia C., Chatenoud L., Altieri A. & Tavani A. 2001. Nutrition and health: Epidemiology of diet, cancer and cardiovascular disease in Italy. Nutr. Metab. Cardiovasc. Dis. 11: 10–15. PMID: 11894740 Lemly A.D. 1996. Evaluation of the hazard quotient method for risk assessment of selenium. ecotox. Ecotoxicol. Environ. Safe. 35: 156–162. DOI: http://dx.doi.org/10.1006/eesa.1996.0095 Lim T.O., Ding L.M., Zaki M., Suleiman A.B., Fatimah S.,Siti S., Tahir A. & Maimunah A.H. 2000. Distribution of body weight, height and body mass index in a national sample of Malaysian adults. Med. J. Malays. 55: 108–128. PMID: 11072496 Lin H.T., Wong S.S. & Li G.C. 2004. Heavy metal content of rice and shellfish in Taiwan. J. Food. Drug. Anal. 12: 167–174. Lopa G. & Adhikari S. 2006. Accumulation of heavy metals in freshwater fish – an assessment of toxic interactions with calcium. Am. J. Food Technol. 1: 139–148. DOI: 10.3923/ajft.2006.139.148 Mansour S.A. & Sidky M.M. 2002. Ecotoxicological studies. 3. Heavy metals contaminating water and fish from Fayoum Governorate, Egypt. Food Chem. 78: 15–22. DOI: http://dx.doi.org/10.1016/S0308-8146(01)00197-2 MFR.1985. Malaysian Law on Food and Drugs. Malaysia law publisher Kuala Lumpur. Monday U.E. & Nsikak U.B. 2007. Cadmium, copper, lead and zinc tissue levels in Bonga shad (Ethmalosa fimbriata) and tilapia (Tilapia guineensis) caught from Imo River, Nigeria. Am. J. Food. Technol. 2: 48–54. DOI: 10.3923/ajft.2007.48.54 Nor Hasyimah A.K., James Noik V., Teh Y.Y., Lee C.Y. & Pearline Ng H.C. 2011. Assessment of cadmium (Cd) and lead (Pb) levels in commercial marine fish organs between wet markets and supermarkets in Klang Valley, Malaysia. Int. Food. Res. J. 18: 795–802. Olowu R.A., Ayejuyo O.O., Adewuyi G.O., Adejoro I.A., Denloye A.A.B., Babatunde A.O. & Ogundajo A.L. 2010. Determination of heavy metals in fish tissues, water and sediment from Epe and Badagry lagoons, Lagos, Nigeria. E-J. Chem. 7: 215–221. DOI: 10.1155/2010/676434 Chi Q.Q., Zhu G.W., Alan L. 2007. Bioaccumulation of heavy metals in fishes from Taihu Lake, China. J. Environ. Sci. (China) 19: 1500–1504. Rashed M.N. 2001. Monitoring of environmental heavy metals in fish from Nasser Lake. Environ. Int. 27: 27–33. DOI: http://dx.doi.org/10.1016/S0160-4120(01)00050Ronagh M.T., Savari A., Papahn F. & Hesni M.A. 2009. Bioaccumulation of heavy metals in Euryglossa orientalis from the Hendijan Seaport (Coastal of Persian Gulf), Iran. J. Biol. Sci. 9: 272–275. DOI: 10.3923/jbs.2009.272.275 Said K.S., Shuhaimi-Othman M. & Kutty A. 2012. The water quality and metal concentrations of Cempaka Lake, Selangor,


Heavy metal level in tilapia fish in Malaysia Malaysia WIT Section 1, pp. 47–52. Transactions on Ecology and the Environment, In: Brebbia C.A. & Zubir S.S (eds), Management of Natural Resources, Sustainable Development and Ecological Hazards, Book Series: WIT Transactions on Ecology and the Environment Series, Vol. 148, WIT Press, 688 pp. ISBN: 978-1-84564-532-8 Salwa A.A. & Shuhaimi-Othman M. 2011. Metals concentrations in eggs of domestic avian and estimation of health risk from eggs consumption. J. Biol. Sci. 11: 448–453. DOI: 10.3923/jbs.2011.448.453 Shao D., Liang P., Kang Y., Wang H., Cheng Z., Wu S., Shi J., Lo S.C. L., Wang W. & Wong M.H. 2011. Mercury species of sediment and fish in freshwater fish ponds around the Pearl River Delta, PR China: Human health risk assessment. Chemosphere 83: 443–448. PMID: 21272914 Shinn C., Dauba F., Grenouillet G., Guenard G. & Lek S. 2009. Temporal variation of heavy metal contamination in fish of the river lot in southern France. Ecotoxicol. Environ. Safe. 72: 1957–1965. DOI: http://dx.doi.org/10.1016/j.ecoenv.2009.06. 007 Song B., Lei M., Chen, T., Zheng Y., Xie Y., Li X. & Gao D. 2009. Assessing the health risk of heavy metals in vegetables to the general population in Beijing, China. J. Environ. Sci. 21: 1702–1709. DOI: http://dx.doi.org/10.1016/S10010742(08)62476-6 Taghipour V. & Aziz S.N. 2010. Determination of trace elements in canned kilka fish marketed in Islamic republic of Iran. World. Appl. Sci. J. 9: 704–707. Taweel A., Shuhaimi-Othman M. & Ahmad A.K. 2011. Heavy metals concentration in different organs of tilapia fish (Oreochromis niloticus) from selected areas of Bangi, Selangor, Malaysia. Afr. J. Biotechnol. 10: 11562–11566. DOI: 10.5897/AJB11.1663

991 Terry P., Lichtenstein P., Feychting M., Ahlbom A. & Wolk A. 2001. Fatty fish consumption and risk of prostate cancer. Lancet 357: 1764–1766. DOI: http://dx.doi.org/10.1016/ S0140-6736(00)04889-3 US-EPA. 2005. Risk-Based Concentration Table, April, 2005. U.S. EPA, Region 3, Philadelphia, PA. http://www.epa.gov/ reg3hwmd/risk/human/index.htm [Accessed 15.07.2012] USFDA 1993a. Guidance Document for Arsenic in Shellfish. United States Food and Drug Administration Center for Food Safety and Applied Nutrition, Washington, DC. USFDA 1993b. Guidance Documents for Trace Elements in Seafood. United States Food and Drug Administration Center for Food Safety and Applied Nutrition, Washington, DC. WHO 1987. Principles for the Safety Assessment of Food Additives and Contaminants in Food. World Health Organization.Environmental Health Criteria, No. 70, Geneva, Switzerland. WHO. 1989. Heavy metals-environmental aspects. World Health Organization, Environmental Health Criteria. No. 85. Geneva, Switzerland. Yap C.K., Ismail A. & Tan S.G. 2004. Heavy metal (Cd, Cu, Pb and Zn) concentrations in the green-lipped mussel Perna viridis (Linnaeus) collected from some wild and aquacultural sites in the west coast of Peninsular Malaysia. Food. Chem. 84: 569–575. DOI: http://dx.doi.org/10.1016/S03088146(03)00280-2 Zauke G.P., Savinov V.M., Ritterhoff J. & Savinova T. 1999. Heavy metals in fish from the Barents Sea (summer 1994). Sci. Total. Environ. 227: 161–173. DOI: http://dx.doi.org/ 10.1016/S0048-9697(99)00014


Received September 7, 2012 Accepted May 10, 2013