Introduction
Because of the very high expensive costs of the local red (from farm animals, as buffaloes, beef, sheep, goats, and camels) and white meats (from poultry, as broilers, ducks, geese, and pigeons), the Egyptian tended to consume (1.8 million ton yearly) more fish than they produce [1.4 million ton, from which 70 % (705 thousand ton from aquaculture, i.e. farming)]. Therefore, Egypt import fish to overcome the increasingly human demand of the nutritional valuable fish (Abdelhamid, 2014b).
Damietta governorate has many advantages in the field of fisheries, since it has marine (Mediterranean Sea), brackish (Manzalah Lake), and freshwater (Damietta branch of the River Nile) bodies; so, it has natural fisheries and pisciculture farms. Therefore, the Damietta population numerously/week eat fish. But unfortunately, the increased environmental pollution, locally and worldwide, consequently also may increase the fish pollution with public health harmful agents (Alsaiedy, 2002).
It is worth noting that water pollution with different contaminants is very clear in the Egyptian coast of the Mediterranean Sea, lakes, and fish farms. This pollution threats the human health and consequently his working capability and economic activity. Heavy metals are one of the most dangerous water pollutants which could carry over into fish. It was clearly reflected in the increased number of hepatic carcinoma patients in Egypt; since, the infected patients' rate had increased from 4% in 1993 to 11% in 2009. Moreover, the death rate among the Egyptians because of the cancer had also increased from 2.8/100000 in 1990 to 10/100000 in 2015. This disturbed the attention of the researchers' community in the field of nutrition and food sciences, for the correlated relationship between the diseases and food pollutants, especially fish. Besides the high incidence rate with other diseases related to fish pollutants via water pollution (Samirabdelghaffar.com/2016).
The benefits of fish and fish product are their high nutrition value, rich of minerals, vitamin A and D, and as a source of n-3 polyunsaturated fatty acids. Consuming of fish product may ameliorate disorders involving thrombosis, blood pressure, arthritis, asthma, arthrosclerosis, tumor growth, etc. However, uncontrolled rearing, handling and processing may result in negative impacts to health. Pollution of fish rearing water may be harmful for fish and human health (Abdelhamid, 2003, 2005, 2009a, b, and 2014a & b). Heavy metal content in fish is due to environmental contamination (Hadiwiyoto, 2000).
Mugil (Bury) fish is a salt-water fish; yet, it could be farmed in brackish as well as fresh-waters, with heavier yield than from saline water. Since Bury is very popular fish species in Egypt as well as most of the Mediterranean basin countries (Abdelhamid, 2003).
The per capita consumption of farmed fish will be greater than wild fish consumption (Koeleman, 2014). In this respect, sludge (night soil or urban waste) may be used in aquaculture. Moreover, fish ponds receiving nutrients derived from treated night soil were less contaminated than ones to which untreated night soil was applied, and the fish reared in them were of superior quality (Ling et al., 1993).
Therefore, the present research aimed to study the possibility of reducing or overcome the heavy metal contamination of fish by using some preparing agents for Bury fish before its cooking, mainly soaking solutions of pomegranate peel, garliclobules and coriander (parsley) seed powders on some heavy metals' (i.e. Pb, Cd, and Hg) concentrations before and after the treatments. The soaking was for three periods (i.e. 10, 20, and 30 m). The fish samples were collected from different sources, mainly marine, Manzalh Lake, and a farm.
Materials and Methods
This study was carried out under the cooperation between Department of Home Economics, Zagazig Faculty of Specific Education, Zagazig University and Department of Animal Production, Mansoura Faculty of Agriculture, Mansoura University during 2017 – 2018. The study aimed to evaluate the effect of preparing mugil fish before cooking using natural agents (pomegranate peel, garliclobules and coriander (parsley) seed powders) on some heavy metals' (i.e. Pb, Cd, and Hg) concentrations before and after the treatments. The soaking was for three periods (i.e. 10, 20, and 30 m). The fish samples were collected from different sources, mainly marine, Manzalh Lake, and a farm.
Fish samples
Fish samples of mullet (Bury fish) from Mediterranean sea (average weight 200g) during June 2017, Lake Manzalh (average weight 200 g), and from a fish farm (average weight 250 g) in Damietta governorate were bought from the local market during July 2017.
Fish samples preparation
The fish were cleaned by removing the scales, gills and eviscerated by removing the complete gut. The fish samples were divided into three groups (according to its sampling location) to be treated with three agents for preparing fish before cooking, being commercial powder of:
- Pomegranate (Punica granatum) peel (external and internal skins),
- Garlic (Allium sativum) lobules,
- Coriander (Coriandrum sativum) seeds (Chinese parsley).
These natural agents were purchased from the local market for spices and medical herbs in powder forms. The fish from each sampling locations were rather divided into four parts, the first part was not soaked in the preparing solutions, whereas the second, the third and the fourth parts were soaked in the preparing solutions with concentrations of 1g powder (of each of the tested natural preparation agents) / 100 g fish for 10, 20 and 30 minutes, respectively as the following:
- Mugil fish marine without soaking.
- Mugil fish marine have been soaked for 10 minutes in Coriandrum sativum solution.
- Mugil fish marine have been soaked for 20 minutes in Coriandrum sativum solution.
- Mugil fish marine have been soaked for 30 minutes in Coriandrum sativum solution.
- Mugil fish marine have been soaked for 10 minutes in garlic solution.
- Mugil fish marine have been soaked for 20 minutes in garlic solution.
- Mugil fish marine have been soaked for 30 minutes in garlic solution.
- Mugil fish marine have been soaked for 10 minutes in pomegranate peel solution.
- Mugil fish marine have been soaked for 20 minutes in pomegranate peel solution.
- Mugil fish marine have been soaked for 30 minutes in pomegranate peel solution
- Mugil fish from Manzalah Lake without soaking.
- Mugil fish from Manzalah Lake have been soaked for 10 minutes in Coriandrumsativum solution.
- Mugil fish from Manzalah Lake have been soaked for 20 minutes in Coriandrumsativum solution.
- Mugil fish from Manzalah Lake have been soaked for 30 minutes in Coriandrumsativum solution.
- Mugil fish from Manzalah Lake have been soaked for10 minutes in garlic solution.
- Mugil fish from Manzalah Lake have been soaked for 20 minutes in garlic solution.
- Mugil fish from Manzalah Lake have been soaked for 30 minutes in garlic solution.
- Mugil fish from Manzalah Lake have been soaked for10 minutes in pomegranate peel solution.
- Mugil fish from Manzalah Lake have been soaked for 20 minutes in pomegranate peel solution.
- Mugil fish from Manzalah Lake have been soaked for 30 minutes in pomegranate peel solution.
- Mugil fish farms without soaking.
- Mugil fish farms have been soaked for 10 minutes in Coriandrumsativum solution.
- Mugil fish farms have been soaked for 20 minutes in Coriandrumsativum solution.
- Mugil fish farms have been soaked for 30 minutes in Coriandrumsativum solution.
- Mugil fish farms have been soaked for 10 minutes in garlic solution.
- Mugil fish farms have been soaked for 20 minutes in garlic solution.
- Mugil fish farms have been soaked for 30 minutes in garlic solution.
- Mugil fish farms have been soaked for 10 minutes in pomegranate peel solution.
- Mugil fish farms have been soaked for 20 minutes in pomegranate peel solution.
- Mugil fish farms have been soaked for 30 minutes in pomegranate peel solution.
After the treatment, the fish was frozen to be easier to cut the muscles for heavy metal analysis.
Fish analysis
The fish was transported from the market to the laboratory in an ice–box. The experimental fish specimens were cooled for a short time then kept frozen for one day (till analysis) to avoid any loss of compounds and to be easy to cut the frozen muscles. The fish were taken from the freezer and kept at room temperature until they were partly thawed. The fish were put on a clean plastic plate, the skin was removed using a knife, and then a flesh sample was tweezed from the lower part of the dorsa–lateral muscle (Dybern (1983). The fish analysis was done in the Animal Nutrition Laboratory, Al- Zagazig Faculty of Agriculture using Atomic Absorption Spectrophotometer (AAS, model 2380, from Perkin Elemer Company, USA), where:
- The sample was cut, weighed (1g) and put in the combustion oven at 500° C for two days ( Ney –m-525 series).
- Add 3 ml of freshly prepared (1:1, v/v) pure perchloric acid / pure – nitric acid (both from ARABLAB, P.O. Box 13543, U.A.E., Fax: 3393318, Tel. 3384985) to each sample in the digestion tubes, then placed aside for about one hour until the first reaction subside (thermo Scientific – Ice 3000 SERIES).
- Fully complement the sample after digestion with distilled water to the known size and run.
- So, the sample is ready to estimate the concentration of the elements steps measurement device.
- Open the power and gas pressure regulator.
- Set the item we want to soundings lamp and adjust the wavelength of the element.
- Drawing the curve record on the computer Waist measuring 3 concentrations equipped and information focus.
- The introduction of the sample for measurement, the computer assigns element concentration in the sample ppm according to Walsh (1955) and Perkin (1964).
Statistical analysis
The obtained numerical data were statistically analyzed using SAS (2006) for analysis of variance. Differences between comparisons among treatment means were made by using Duncan multiple ranges test (Duncan, 1955).
Results
Heavy metals of fish rearing water:
Data of the heavy metals analysis (ppm) in the fish rearing water from the sampling locations (sea, lake, and farm) for lead (Pb) were 0.0032, 1.2775, and 0.0681; for cadmium (Cd) 0.0011, 0.0000, and 0.0431; and for mercury (Hg) 0.0170, 0.0003, and 0.0042, respectively. That means that Pb concentration was at highest in the lake water followed by the farm water then the sea water. Whereas, Cd was absent from the lake water, but highest level was found in the farm water followed by the sea water. However, Hg level was at highest in the farm water, followed by the sea water and at least in the lake water. In other words, the farm water was polluted with the highest level (ppm) of both studied heavy metal (0.0431 Cd, and 0.0042 Hg), whereas the lake water was the highest concerning Pb (1.2775 ppm). Generally, the level of water Pb was higher than water Cd than water Hg, respectively.
Heavy metals of Mugill cephalous's muscles:
Samples of Bury fish collected from sea, lake, and farm and treated with coriander, garlic, and pomegranate for 0, 10, 20, and 30 min. were analyzed for Pb, Cd, and Hg in their muscles. Data presented in Table 1 revealed presence of significant (P≤0.05) differences among sampling locations as well as the treatment period in concentration of the three heavy metals tested. Lakes fish samples were the highest (P≤0.05) in Pb concentration, followed by sea then farm samples. But farm samples were the highest (P≤0.05) followed by sea fish samples concerning Cd levels. However, Hg level in the sea fish samples was the highest followed by farm then lake's samples. Also, there were significant (P≤0.05) differences among treatment agents in the Pb and Hg levels. Since pomegranate significantly (P≤0.05) reduced the level of the three heavy metals than the other two agents. The treatment generally reduced the heavy metals concentration comparing with zero time, i.e. before treatment. Moreover, prolonged treatment period (20 and 30 min.) generally reduced (P≤0.05) the heavy metals level, particularly in Pb and Cd. The interactions of two or the three variables (sampling location, treatment agent, and treatment period) were significant (P≤0.03 – 0.0001) too.
The interaction between sampling locations and the treatment agents:
Pomegranate reduced Pb level in fish muscles from the three sampling locations than the other treatment agents (coriander and garlic). The other two heavy metals (Cd and Hg) did not reflect interaction between sampling location and treatment agent (Table 2). Lake fish samples were contaminated with higher levels of Pb > sea > farm samples. Whereas, the farm fish samples were more contaminated with Cd > sea > lake samples. Yet, sea fish samples reflected the highest Pg concentrations > farm > lake samples. Regardless to sampling locations and treatment agents, the levels of Pb were > Hg > Cd.
The interaction between sampling locations and the treatment period:
Lake samples were contaminated with Pb > sea > farm samples. Whereas, sea fish samples were contaminated with Cd and Hg > farm > lake samples. It was clear that increasing the treatment period had decreased the residues of all tested heavy metals in the fish flesh from the three sampling locations (Table 3).
The interaction between the treatment agents and the treatment period:
Table 4 shows that coriander and garlic were not effective in reducing Pb concentration as the pomegranate. The three treatment agents were mostly equal in reducing Cd levels than before treatment. Coriander and pomegranate were better than garlic in reducing Hg level in the fish flesh. All treatment periods reduced the heavy metals' concentrations than before treatment (control).
The interaction between the three variables (sampling locations, treatment agents and the treatment period):
Table 5 shows in general that the overall mean of Pb level (0.352 ppm) was > Hg (0.132 ppm) > Cd (0.025 ppm), regardless to all three variables. Moreover, lake fish samples were more contaminated with Pb than sea and farm samples, being 0.547, 0.378, and 0.132 ppm, respectively. But, farm fish samples were more contaminated with Cd than sea and lake ones, being 0.049, 0.25, and 0.000 ppm, respectively. Yet, samples of sea fish flesh were more contaminated with Hg than farm and lake samples, being 0.380, 0.015, and 0.001 ppm, respectively. However, the overall means of heavy metals' concentrations in the sea fish samples were 0.380, 0.378, and 0.025 ppm Hg, Pb, and Cd, respectively. Lake samples contamination levels took the descending order Pb, Hg, and then Cd, being 0.547, 0.001, and 0.000 ppm, respectively. Finally, farm fish flesh samples reflected the descending order of heavy metal contamination levels as Pb, Cd, and Hg, being 0.132, 0.049, and 0.015 ppm, respectively. The effect of the treatment agents differed depending on different variables as the effect of the interaction (s).
The effect of sampling locations (regardless to the other two variables, treatment agents and treatment period):
The overall means for the contamination levels of Pb were significantly (P>0.05) higher in lakes fish flesh samples than in sea and farm samples as shown from Table 6. But, Cd levels were higher (P>0.05) in farm samples than sea and lake samples. Yet, the Hg concentration in fish flesh sampled from the sea was higher (P>0.05) than those in fish samples belonging to farm and lake.
Effect of the interaction between treatment agents and treatment periods for the sea fish samples:
Table 7 shows no significant (P≥0.05) differences in Pb and Cd concentrations among treatment agents tested; yet, there were significant (P≤0.0001) differences among treatment agents concerning Hg, being the highest in garlic treated samples than in coriander and pomegranate treated ones. Also, treatment periods did not significantly (P≥0.05) affect concentrations of both Pb and Cd, but significantly (P≤0.0001) affected Hg levels, being the lowest at 20 and 30 min. comparing with those at 10 min. The interaction effect between treatment agents and treatment periods on the heavy metals' levels was non-significant (P≥0.05) for Pb and Cd but significant (P≤0.0001) for Hg in the sea fish samples.
Effect of the interaction between treatment agents and treatment periods for the lake fish samples:
Table 8 shows that lake fish samples did not differ significantly (P≥0.05) among different treatment agents for Pb and Hg; whereas, Cd was absent. Treatment periods affected significantly (P≤0.0001) both Pb and Hg concentrations; however, Cd was absent as mentioned before. The interaction (treatment agent* treatment period) effect was not significant (P≥0.05).
Effect of the interaction between treatment agents and treatment periods for the farm fish samples:
Table 9 presents the means ± standard errors of different heavy metals concentrations tested in the fish flesh collected from farm concerning the effects of treatment agents, treatment periods, and their interactions. There were no significant (P≥0.05) effects of treatment agents on all tested heavy metals tested. Yet, the treatment periods affected significantly only on Cd (P≤0.01) and Hg (P≤0.05) but not significantly (P≥0.05) on Pb. The interactions' effects for both variables on all tested heavy metals in farm samples were not significant (P≥0.05).
Discussion
Pollution took different forms, due to various sources, and affects all living organisms and not living surfaces. So, it is a very big problem facing human beings that negatively affect its life and environment. Not only air, water, food, health, production and economy but also human moral (Abdelhamid, 1999; 2000, 2001 and 2009c). So, it is a legal must to take considerations from the responsible authorities for treating all kinds of wastewaters before reaching water bodies to protect aquatic life and consumers (Abdelhamid et al., 2007).
Fish rearing water and sampling locations:
It was noticed from the obtained results that means of Pb concentration were at highest in the lake water followed by the farm water then the sea water. Whereas, Cd was absent from the lake water, but highest level was found in the farm water followed by the sea water. However, Hg level was at highest in the farm water, followed by the sea water and at least in the lake water. In other words, the farm water was polluted with the highest level of both studied heavy metals, whereas the lake water was the highest concerning Pb. Generally, the level of water Pb was higher than water Cd than water Hg, respectively.
However, water pollution reduces the fish growth and fish fertility, alters the fish taste, responsible for fish mortality. Polluted water produces contaminated fish that is harmful to the consumers (humans). So, the responsible authorities lay out tolerance limits for most pollutants, particularly those classified as very toxic minerals, e.g. Cd, Hg, and Pb in the fish rearing water as 0.01 ppm for Cd and 0.10 ppm for Pb. Moreover, the sea water do not contains Cd, but contains 0.0003 ppm Hg and 0.004 – 0.005 ppm Pb (Abdelhakeem et al., 2002). Yet, the allowable levels of Cd, Hg, and Pb in rearing water for fish according to W.H.O (1984) were 0.005, 0.001, and 0.05 ppm.The standard prescriptions of the suitable water for fish farming limit the heavy metals as 0.0005 ppm Cd, > 2.00 ppm Hg, and > 0.02 ppm Pb (U.S. EPA, 1974). Accordingly, the water from lake and farm contained more Pb than the save level. Also, sea and farm waters were not safe concerning their content of Cd. Abdelhamid and El-Ayouty (1991) proved that rearing water polluted with inorganic Pb was toxic but the organic Pb was not. Since, inorganic Pb led to fish mortality, and pathological findings, e.g. haemorrhage and congestion of the gastrointestinal tract and kidneys. Moreover fish body protein decreased and the body fat increased proportional to the pollution level.
El-Safy and Al-Ghannam (1996)registered higher concentrations for the three heavy metals in Lake Manzala water than our results, with higher concentrations in 83% of the water samples than the permissible limits. Since Lake Manzala suffers from continuous industrial, agricultural and sewage pollution which adversely affect its aquatic environment. Sampling location within Lake Manzala significantly affects level of the heavy metals in the lake's water. Moreover, heavy metals polluted rearing water of fish negatively affects fish health, productivity, and genetics (Magouz et al., 1996). Abdelhamid et al. (1997 and 2013a & b) and Abdelhamid and Gawish (1998) reported variations in the water heavy metal levels due to sampling locations. Salem (2003) found that the heavy metals pollution reduced fish muscles area. Abdelhamid et al. (2013a) gave the following order of heavy metals concentration in water Cd > Pb. Abdelhamid et al. (2013b) calculated significant correlations among heavy metals' levels in fish.
Bury fish and sampling locations:
Heavy metals analysis for Bury fish revealed presence of significant differences among sampling locations as well as the treatment period in concentration of the three heavy metals tested. Lakes fish samples were the highest in Pb concentration, followed by sea then farm samples. But farm samples were the highest followed by sea fish samples concerning Cd levels. However, Hg level in the sea fish samples was the highest followed by farm then lake's samples. Also, there were significant differences among treatment agents in the Pb and Hg levels. Since pomegranate significantly reduced the level of the three heavy metals than the other two agents. The treatment generally reduced the heavy metals concentration comparing with zero time, i.e. before treatment. Moreover, prolonged treatment period (20 and 30 min.) generally reduced the heavy metals level, particularly in Pb and Cd. The interactions of two or the three variables were significant too.
For the good luck, the heavy metals accumulate at the lowest concentration in edible parts of the fish (Abdelhamid et al., 2000b). Abdelhakeem et al. (2002) cited the tolerance levels of Cd and Pb in the fresh fish body as 0.50 and 2.00 ppm. El-Safy and Al-Ghannam (1996)registered higher concentrations for the three heavy metals in Lake Manzala fish than our results, with higher concentrations in 6.94, 28.7, and 100% of the fish samples than the permissible limits of Pb (1.00 ppm, EGASQC, 1991), Hg (0.50 ppm, EGASQC, 1991), and Cd (0.10 ppm, EGASQC, 1991), respectively. Since Lake Manzala suffers from continuous industrial, agricultural and sewage pollution which adversely affect its aquatic environment. So, fish (particularly tilapia and catfish) are the most common food for the Egyptians. Sampling location within Lake Manzala significantly affects the level of the heavy metals in the lake's fish. The highest Pb levels were found in muscles of Mugilcephalus, Tilapiaaurea, and catfish, perhaps for their feeding habits as omnivorous and bottom feeders, while catfish live impeded in bottom mud of higher metal concentration. Mugilcephalus showed the lowest Cd levels.
Abdelhamid et al. (1997) found variations in the fish body concerning the heavy metals level due to sampling locations. They added that the levels of heavy metals in the fish carcass were higher than those in the rearing water. Moreover, Pb and Cd levels in the fish musculature were over the permissible levels. Additionally, Mugil cephalus is more frequently contaminated than Liza ramada than Sparus aurata. Abdelhamid and Gawish (1998) found the heavy metals' levels in shrimp and crab in the descending order Cd ≤ Hg ≤ Pb. They added that 100% of the samples were refused for their higher Cd contents than the permissible level, 47.6 and 70% were unacceptable for their higher Hg contents, in addition to 35.7 and 42% because of the high Pb concentrations. So, they advised to treat the pollution sources before their reach to the water bodies and till this, consumption of such contaminated sea foods should be restricted to avoid public health risks.
However, levels of heavy metals are correlated with salinity changes due to the discharge of water (Radwan, 2000). The latest author also reported an effect of sampling locations on heavy metals' levels in fish. Abdelhamid et al. (2006b) found thatheavy metals elevate serum lysozyme activity of fish as well as total leukocytes count and differential count, while the intestinal scrapping and skin mucus had low activity besides erythrocytes, platelet counts, and serum protein also decrease. Hematocrit and hemoglobin values were also decreased. Abdelhamid et al. (2013a) gave the following order of heavy metals in fish Pb > Cd. They calculated significant correlationsamong heavy metals' concentrationsin water and fishfrom one side and chemical composition of the fish. Gawish and Hosni (2017) found that Pb level in fish muscles was higher than Cd one. They found also correlations between heavy metals' levels and chemical composition of the fish. Their findings of heavy metals' concentrations were higher than those found from our study.
Sampling Locations:
The overall mean of Pb level was > Hg > Cd, regardless to all three variables. Moreover, lake fish samples were more contaminated with Pb than sea and farm samples. But, farm fish samples were more contaminated with Cd than sea and lake ones. Yet, samples of sea fish flesh were more contaminated with Hg than farm and lake samples. However, the overall means of heavy metals' concentrations in the sea fish samples were 0.380, 0.378, and 0.025 ppm Hg, Pb, and Cd, respectively. Lake samples contamination levels took the descending order Pb, Hg, and then Cd. Finally, farm fish flesh samples reflected the descending order of heavy metal contamination levels as Pb, Cd, and Hg. The effect of the treatment agents differed depending on different variables as the effect of the interaction (s).
The overall means for the contamination levels of Pb were significantly higher in lakes fish flesh samples than in sea and farm samples. But, Cd levels were higher in farm samples than sea and lake samples. Yet, the Hg concentration in fish flesh sampled from the sea was higher than those in fish samples belonging to farm and lake. It is well known that the sampling location has a significant effect on the heavy metals content of the soils mainly (El-Ayoty et al., 1987). The heavy metals are found often in different feedstuffs naturally (Abdelhamid, 1988; Abdelhamid and El-Ayoty, 1989 and Abdelhamid et al., 1992) as well as in water, soil and fish (Abdelhamid et al., 1997). So, this contamination affects not only fish health and survival (Abdelhamid and El-Ayoty, 1991; Abdelhamid and El-Zareef, 1996; Abdelhamid et al., 2000a & b, 2006 a and 2014a, b, & c; and Abdelhamid and Ibrahim, 2003) but also human health (Shata, 1996). Since water pollution with heavy metals is responsible for occurring ca. thirty two danger diseases [1 Carcinoma, 2 Cirrhosis, 3 Nephritis, 4 Abortion, 5 Hepatosplenomegaly, 6 Hypogonadism, 7 Parkinsonia, 8 Degenerative disorders, 9 Epilepsy, 10 High toxic subs., 11 Abdominal pain, 12 Anemia, 13 Arthritis, 14 Myopathy, 15 Myocarditis, 16 Headache, 17 Nausea & vomiting, 18 Fatigue, 19 Fetal damage, 20 Osteomalacia, 21 Periphnuritis, 22 Weight loss, 23 Skeletal deformity, 24 Diarrhea, 25 Delay in wound healing, 26 Alopecia, 27 Bronzing of skin, 28 Hyperkeratosis, 29 Alkalinity, 30 Taste changes, 31 Salivation, 32 Anorexia] (Abdelhamid, 2000 and 2006).
So, Abdelhamid (2006) reviewed the identification, importance and sources of heavy metals in the aquatic media. He concentrated on the wide spreading of heavy metals in the Egyptian waters, i.e. seas, lakes and River Nile. Thereafter, he focused on their toxic effects on fish as well as their dangerous effects on humans. Moreover, the variations among sampling locations concerning heavy metals' contents in rearing water of the tested fish as well as in the tested fish themselves were reported before by many researchers (Abdelhamid and El-Zareef, 1996; Abdelhamid et al., 1997; 2006; & 2013 a & b; Abdelhamid and Gawish, 1998 and Abdelhamid, 2006). Variation among sampling locations concerning heavy metals concentration in mullet (from desert cultivated and those from natural fisheries) had been reported before by Abdelhamid et al. (2006 a).
Farmed fish are susceptible for many sources of pollution with heavy metals, whether from its soil (Abdelhamid et al., 1992 and 1997), rearing water [contaminated with different drainage sources (Abdelhamid and El-Zareef, 1996), agricultural (Abdelhamid and Ibrahim, 2003), industrial (Abdelhamid et al., 2000b and 2013b), and sanitary (Abdelhamid et al., 2014 a, b and c)]. Such stress factors may negatively affect fish physiology (Abdelhamid et al., 2006a and b) and survival and hence fish production (Abdelhamid, 2006 and Abdelhamid et al., 2000 a). Abdelhamid et al. (2014 c) fed polycultured fish (Nile tilapia, silver carp, common carp, and African catfish at a rate 1: 1: 1: 1) the dried sewage sludge (DSS) that contains higher levels of P, Cu, Pb, and Cd than the commercial control diet. So, DSS-fed fish contained more P and Cd levels than the control fish. Even the control fish muscles presented higher contents of Cu, Pb, and Cd. Therefore, it is recommended to give more concern on food and water quality (environmentally friendly) used in aquaculture to offer safe products for human consumption. Moreover, it is not recommended to use sewage sludge in fish feeding, although its use in cultured fish feeding is wide-spreading in Kafr El-Sheikh governorate (Abdelhamid et al., 2014 a).
Lakes are also polluted with heavy metal, even the parks (protected areas) as reported by Abdelhamid et al. (2013 a) in Ashtoum El-Gamil park (Lake Manzalah). Those authors revealed that there were significant (P≤0.0001) differences among sampling seasons and stations as well as their interactions concerning the levels of heavy metals tested in water, sediment, or fish. The elements level took the descending order Zn ≥ Cd ≥ Pb ≥ Fe ≥ Cu in the water, Pb ≥ Fe ≥ Cu ≥ Zn ≥ Cd in the sediment, and Fe ≥ Pb ≥ Zn ≥ Cu ≥ Cd in the fish body samples. Some significant correlations were calculated among heavy metals (in water, sediments, and fish) and chemical composition of the fish.
Lake Manzalah is one of the most important aqua systems, which receives effluents discharges from heavily industrialized and highly populated settlements, Metals tend to accumulate in water and move up through the food chain. So, studies to ascertain the level of heavy metals in the environment and determine potentially hazardous levels for human are necessary. Heavy metals (Pb, Cd, Fe, Cu, and Zn) were determined in muscle and gill of Tilapia nilotica from the south part of Manzala Lake to assess the lake water pollution with those toxic metals. The levels of Pb were higher than the maximum permissible limits for human consumption. In conclusion, the levels of heavy metals observed in the fish and water samples can be considered as a serious matter. More safe and economic methods for the elimination of heavy metals from contaminated waters are needed and continuous assessment of the level of pollution of the lake waters and fish with heavy metals is also necessary. Safe disposals of domestic sewage and industrial effluents, as well as enforcement of laws enacted to protect our environment, are therefore advocated (EL-Shafei, 2015).
Cadmium (Cd) and lead (Pb) are toxic heavy metals that cause adverse health effects in humans and animals. Chelation therapy, the conventional treatment for heavy metal toxicity, is reported to have a number of safety and efficacy issues. Recent studies have shown that dietary supplements play important roles in protecting against Cd and Pb toxicity. The protective effects of essential metals, vitamins, edible plants, phytochemicals, probiotics and other dietary supplements against Cd and Pb toxicity had been reviewed and described the proposed possible mechanisms. Based on these findings, dietary strategies are recommended for people at risk of Cd and Pb exposure. The application of these strategies is advantageous for both the prevention and alleviation of Cd and Pb toxicity, as such supplements can be added easily and affordably to the daily diet and are expected to have very few side effects compared to the chelation therapy (Zhai et al., 2015).
Treatments:
Pomegranate reduced Pb level in fish muscles from the three sampling locations than the other treatment agents. The other two heavy metals (Cd and Hg) did not reflect an interaction between sampling location and treatment agent. Lake fish samples were contaminated with higher levels of Pb > sea > farm samples. Whereas, the farm fish samples were more contaminated with Cd > sea > lake samples. Yet, sea fish samples reflected the highest Hg concentrations > farm > lake samples. Regardless of sampling locations and treatment agents, the levels of Pb were > Hg > Cd.
Lake samples were contaminated with Pb > sea > farm samples. Whereas sea fish samples were contaminated with Cd and Hg > farm > lake samples. It was clear that increasing the treatment period had decreased the residues of all tested heavy metals in the fish flesh from the three sampling locations.
Coriander and garlic were not effective in reducing Pb concentration as the pomegranate. The three treatment agents were mostly equal in reducing Cd levels than before treatment. Coriander and pomegranate were better than garlic in reducing Hg level in the fish flesh. All treatment periods reduced the heavy metals' concentrations than before treatment (control).
There were no significant differences in Pb and Cd concentrations among treatment agents tested; yet, there were significant differences among treatment agents concerning Hg, being the highest in garlic treated samples than in coriander and pomegranate treated ones. Also, treatment periods did not significantly affect concentrations of both Pb and Cd, but significantly affected Hg levels, being the lowest at 20 and 30 min. comparing with those at 10 min. The interaction effect between treatment agents and treatment periods on the heavy metals' levels was non-significant for Pb and Cd but significant for Hg in the sea fish samples.
The lake fish samples did not differ significantly among different treatment agents for Pb and Hg; whereas, Cd was absent. Treatment periods affected significantly both Pb and Hg concentrations; however, Cd was absent as mentioned before. The interaction (treatment agent* treatment period) effect was not significant.
There were no significant effects of treatment agents on all tested heavy metals tested. Yet, the treatment periods affected significantly only on Cd and Hg but not significantly on Pb. The interactions' effects for both variables on all tested heavy metals in farm samples were not significant.
For this pollution, many attempted were carried out concerning removal or reducing the contamination level, e.g. via different concentrations of ethylene diamine tetraacetic acid (EDTA) or cooking methods to ameliorate Pb level from mullet and tilapia (Abdelhamid et al., 2011). The reducing effect on heavy metals 'concentration of some natural agents such as the extracts of garlic, coriander, and pomegranate may be attributed to their natural contents of some phenolic compounds that have capability to bind with heavy metals contaminate fish, and could be removed from fish by washing the fish with current water. Natural agents were used too for the same reason of overcome the toxic effects of heavy metals as garlic (Allium sativum) which its extract was used against nickel II and chromium VI. The results indicate that garlic (Allium sativum) has some beneficial effect in preventing heavy metal (nickel and chromium VI) induced alteration of lipid profile (Gupta et al., 2008).
The prophylactic efficacy of garlic (Allium satium L.) extract to reduce tissue lead (Pb) concentration was evaluated experimentally in rats (Abo Alnasr, 1999). Concomitant use of garlic extract was found to reduce lead concentration considerably indicating the potential therapeutic activity of garlic against lead (Anon., 2001). Garlic was used by Nwokocha et al. (2011) for reducing some heavy metal accumulation in liver of Wistar rats. Cha (1987) studied the effect of garlic in ameliorating poisoning of Cd and Hg in rats. Al Kholy (2013) used the garlic oil to reduce Pb toxicity in rats. Saad El-Deen andAbd El-Naser (2014) reported too that cultured garlic contains essential components as Alliin, Alliinase, Allicin, Scordinins, Sapnins, Selenium and a group of vitamins (A, B1, B2, C, E) and minerals. So, it is used as an antioxidant. Cha (1987) found that when treating rats with garlic in the presence of Cd and Hg, it acts as a protective against the heavy metals toxicity. It reduces also the accumulation of these heavy metals in the internal organs, tests and bone of rats and increases their excretion. So, garlic could be used to capture heavy metals.
The dry coriander fruits are known as coriander seeds. The seeds have a lemony citrus flavor when crushed, due to terpenes linalool and pinene. Types with smaller fruit are produced in temperate regions and usually have volatile oil content around 0.4-1.8%, so are highly valued as a raw material for the preparation of essential oil (Smallfield, 1993). Aga et al. (2001) studied the preventive effect of Coriandrumsativum (Chinese parsley) on Pb deposition in mice. Also, Kansal et al. (2011) and Sharma and Kansal (2011) protected male mice against Pb toxicity via coriander. However, the contents of Pb and Cd in coriander grown in an effluent irrigated fields in the vicinity of an industrial area of Faisalabad, Pakistan were assessed. The leaves of coriander contained higher concentrations of Cd and Pb as compared to other parts (Farooq et al., 2008). Yet, there is a study describes antioxidant effect of Coriandrum sativum against lead nitrate induced toxicity in mice. Lead caused a significant decrease in antioxidant enzyme activity and this effect was reversed in groups treated with plant extract. Treatment with coriander significantly reduced the adverse effects related to most of biochemical parameters altered in animals treated with lead, related to hepatic and renal oxidative stress. Oral administration of coriander to lead treated mice attenuated the deranged histopathological changes to some extent. It can be concluded from these results that Coriandrum sativum protects against lead toxicity and warrants the identification and isolation of active compounds responsible for its antioxidant effects (Leena et al., 2011).
Compared to the pulp, the inedible pomegranate peel contains as much as three times the total amount of polyphenols, including condensed tannins (Plumb et al., 2002), catechins, gallocatechins and prodelphinidins (Chidambara et al., 2002). Pomegranate is containing numerous antioxidants. Its peel (external and internal skins) forms about 26-30% of the fruit's weight and contains also huge amounts of antioxidants, e.g. flavonoids and tannins that concentrate mainly in the skin, and make ca. 92% of the total antioxidants in the fruit (Ismailet al., 2012). So, the skin of the pomegranate fruit is more beneficial than its peel (Al-Muammar andKhan, 2012 and Shark, 2016). Abd Elraziq (2016) removed Pb from drainage water via pomegranate peel. Pomegranate peel with its antioxidants content is very effective in removing the toxic substances (Shark, 2016).
Conclusion
Consequently, all tested water and fish (Bury) samples collected from different studied locations were contaminated with higher Cd, Hg and/or Pb than the tolerance levels. Treating fish before cooking with some natural agents, particularly with pomegranate peels for 20 – 30 minutes reduced the heavy metals' residues in the fish. Yet, the prophylactics are better than treating, i.e. treating different drainages before turnoff the wastewaters into surface water is a must. Also, man must buy his aquatic foods from trustful sources. Thereafter the role of such natural treating agents could help in reducing the residues of such contaminants.
