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Organochlorine contamination in some marketable fish in Egypt
Chemosphere 54 (2004) 1401–1406 www.elsevier.com/locate/chemosphere
Organochlorine contamination in some marketable fish in Egypt Ahmed El Nemr *, Aly M.A. Abd-Allah National Institute of Oceanography and Fisheries, Janaklees, Kayet Bay, Alexandria, Egypt Received 5 March 2003; received in revised form 18 August 2003; accepted 10 October 2003
Abstract Ten organochlorine compounds were analyzed in four species of fish (Bouri Mugil spp., Denis Sparus auratus, Moza Boops boops and Mousa Pegusa lascaris), from four Egyptian governorates (South Sinai, Suez, Port-Said and Demietta). Although all fish studied are bottom or near-bottom feeders, remarkable variations between studied species were noticed. The grand total values recorded at the studied governorates were in descending order: Bouri > Denis > Moza > Mousa. The highest concentration of pesticides was recorded in Demietta governorate fish (20–211 ng/g of wet weight) and the p,p0 -DDE dominated over the other p,p0 -isomers in all studied fish, while dieldrin was the dominated in the studied cyclodiene compounds. However, hexachlorobenzene (HCB) occurred at all studied governorate fish except Mousa fish from South Sinai. Toxaphene was detected only in fish (Bouri, Denis, and Mousa) from Demietta governorate. Chlordane was not detected in any studied fish. The level of organochlorine pesticides contamination in fish from the studied governorates is relatively low and should not pose a health risk to consumers. 2003 Elsevier Ltd. All rights reserved. Keywords: Egypt; Organochlorine pesticides; Bouri; Denis; Moza; Mousa
1. Introduction In Egypt, organochlorine pesticides were used from the 1950s until 1981. This class of chemicals is characterized by persistence in the environment and the tendency to accumulate in aquatic organisms. Although Egypt is the largest pesticide market in Arabian countries and the fourth largest importer of pesticides among developing countries (Yamashita et al., 2000), there are no regular monitoring programs in Egypt for identification and determination of pesticides in the environment.
*
Corresponding author. Fax: +20-3-574-0944. E-mail address: [email protected] (A. El Nemr).
There are numerous reports on organochlorine residues in the Egyptian coastal marine environment, but not for toxaphene, which was heavily used in early 1960s (El-Dib and Badawy, 1985; Abdallah and Ali, 1994; Abdallah et al., 1998; Yamashita et al., 2000). El-Sebae et al. (1993) reported the heavy use of toxaphene (54,000 metric tons), endrin (10 500 metric tons) and DDT (13 500 metric tons). Toxaphene is a complex mixture of chlorinated terpenes, probably hepta-, octa-, and nonachlorobornanes with the analog (2-exo,3-endo,5-exo,6endo,8,8,9,10,10-nonachlorobornane) being used as a toxaphene marker in gas chromatography analysis. The purpose of the present study is to determine the levels of some organochlorine pesticides such as cyclodienes compounds (including heptachlor, heptachlor epoxide, and dieldrin), DDT’s isomers (including p,p0 isomers of DDT, DDE and DDD) and hexachlorobenzene (HCB), toxaphene, lindane and chlordane in different species (Bouri Mugil spp., Denis Sparus auratus,
0045-6535/$ - see front matter 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2003.10.041
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Table 1 Common and scientific names, food, weight, and length of fish samples surveyed from different Egyptian governorates (1: Demietta, 2: Port Said, 3: Suez and 4: South Sinai) Common
Length (cm)
Weight (g)
Food
Scientific name
Bouri Denis Moza Mousa
18.4–22.6 14.3–18.7 11.5–16.4 9.6–16.8
66.7–80.4 50.2–61.1 29.2–33.4 14.8–19.5
Algae, organic matter Molluscs, crustacea Sea weeds, sponges, small crustacea Small molluscs, worms and crustacea
Mugil spp. Sparus auratus Boops boops Pegusa lascaris
Moza Boops boops and Mousa Pegusa lascaris) from marketable Egyptian fish from the Demietta, Port Said (Mediterranean Sea), Suez and South Sinai (Red Sea) Governorates (Table 1).
2. Materials and methods Fish samples were collected from local fishermen at sites 1–4 in October 2001 (Fig. 1), and kept frozen )20 C prior to analysis. White tissues (muscle) were sampled by section from 10 individuals of each fish species and tissues of same species were mixed to make composite samples (two samples of each fish). From each composite sample, two replicates each 20 g, were taken and mixed with 60 g of anhydrous sodium sulphate for drying prior to Soxhlet extraction. Extraction with hexane (200 ml) was carried out for 8 h. The n-hexane extract was rotary evaporated at 35 C to 15 ml, and transferred into a Kuderna-Danish concentrator to reduce the volume to 5 ml. Lipid content was determined from 20 ml aliquots of the sample extracts that were allowed to evaporate until dry. The residue was redissolved in 1 ml of methylene chloride, 0.1 ml was placed on filter paper and evaporated, and the residual mate32°
Mediterranean Sea
1 Demietta
2
Port Said
31°
Cairo
30°
Suez
3
29° South Sinai 4
28°
Egypt
27°
26°
Saudi Arabia
Red Sea
29°
30°
31°
32°
33°
Fig. 1. Samples locations.
34°
35°
rials were weighed. The extract was further reduced to 1 ml under a gentle stream of pure nitrogen gas. The fractionation was done on a Florisil (20 g) column (activation of the florisil was achieved by heating at 130 C for 12 h followed by partially deactivated with 0.5% water by weight and stored in a tightly sealed glass jar with ground glass stopper and the mixture were allowed to equilibrate for one day before use. The first fraction, eluted by n-hexane (60 ml), contained HCB, heptachlor epoxide, dieldrin, and p,p0 -DDE. The second fraction (50 ml, n-hexane/methylene chloride, 70:30) contained DDD and DDT. The third fraction was eluted by nhexane/methylene chloride (1:1, 50 ml) and contained lindane and toxaphene. Each fraction was concentrated and injected into a Hewlett Packard 5980 series II highresolution gas chromatograph (Hewlett Packard, USA) equipped with a 63 Ni electron capture detector (ECD). A fused silica capillary column (50 m · 0.32 mm · 0.52 lm) coated with DB-1 (5% diphenyl and 95% dimethyl polysiloxane) was used for the quantification. The oven temperature was programmed from an initial temperature of 70 C (2 min hold) to 260 C at a rate of 3 C min1 and was then maintained at 260 C for 20 min. Injector and detector temperatures were maintained at 250 and 300 C, respectively. Helium was used as the carrier (1.5 ml min1 ) and nitrogen as the make-up (60 ml min1 ) gas. Concentrations of individually resolved peaks were summed to obtain the total organochlorine concentration. An equivalent mixture provided by Dr. Ehrenstorfer Laboratories (Augsburg, Germany) with known organochlorine composition and content was used as the standard. Organochlorine pesticides were quantified by matching individually resolved peak areas with the corresponding peak areas of the external standards (POC mixture provided by IAEA). To control the analytical reliability and evaluate recovery efficiency and accuracy of the results, two replicates were conducted on organochlorine compound reference materials SRM 1588 (Cod fish, provided by EIMP-IAEA) every six samples. The laboratory results showed that recovery efficiency ranged from 88% to 103% with a coefficient of variation (CV) of 9–17%. Compounds were identified by matching retention time against those of authentic standards. The detection limits were 0.3 ng/g for studied organochlorine compounds.
A. El Nemr, A.M.A. Abd-Allah / Chemosphere 54 (2004) 1401–1406
3. Results and discussion The analytical results are presented as ng/g of the wet weight in Tables 2 and 3. The highest levels of organochlorine pesticides were found in Bouri fish while the lowest levels were recorded in Mousa fish collected from
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all four governorates (Figs. 2 and 3). The total concentrations of the 10 organochlorine compounds were present in fish in the following descending order: Bouri > Denis > Moza > Mousa in all studied locations (Tables 2 and 3). There was remarkable variation among the species studied, although all studied fish are bottom
Table 2 Average concentration of organochlorine (ng/g of wet weight) in fish collected from South Sinai and Suez Location South Sinai (fish sample)
EOM (mg/g of wet wt.) HCB Lindane Heptachlor Heptachlor epoxide Dieldrin Total cyclodienes p,p0 -DDT p,p0 -DDE p,p0 -DDD Total DDTs Toxaphene Chlordane Grand total %C %D
Suez (fish sample)
Bouri
Denis
Moza
Mousa
Bouri
Denis
Moza
Mousa
77 20.3 ± 9.6 N.D. N.D. 3.6 ± 2.2 13.3 ± 5.7 16.9 ± 8 N.D. 18.2 ± 11.3 N.D. 18.2 ± 11.3 N.D. N.D. 55.4 ± 29 31 33
65 12.2 ± 4.4 2.1 ± 0.8 N.D. 5.4 ± 3.1 6.9 ± 4.8 14.4 ± 8 N.D. 11.3 ± 9.8 3.8 ± 2.3 15.1 ± 12 N.D. N.D. 41.7 ± 25 29 36
47 5.4 ± 1.9 N.D. N.D. 1.1 ± 0.4 3.3 ± 1.2 4.4 ± 16 1.1 ± 1.3 6.1 ± 1.2 N.D. 7.2 ± 3 N.D. N.D. 17.0 ± 6 26 42
33 N.D. N.D. N.D. 1.4 ± 0.6 N.D. 1.4 ± 0.6 1.5 ± 0.4 5.1 ± 2 0.5 ± 0.2 7.1 ± 2.4 N.D. N.D. 8.5 ± 3.0 17 83
54 33.8 ± 12.2 2.4 ± 2.1 N.D. 1.1 ± 0.4 7.7 ± 2.6 8.8 ± 3.0 5.2 ± 3.1 12.8 ± 9.4 3.2 ± 1.3 20.1 ± 14 N.D. N.D. 66.2 ± 31 13 30
45 20.1 ± 9.9 2.1 ± 1.7 N.D. 0.9 ± 0.3 3.5 ± 2.1 4.4 ± 2.4 1.1 ± 0.8 7.4 ± 2.4 3.1 ± 1.5 11.6 ± 5 N.D. N.D. 38.2 ± 19 12 30
39 10.2 ± 6 N.D. N.D. N.D. 2.1 ± 1.3 2.1 ± 1 N.D. 3.4 ± 2.1 6.5 ± 2.7 9.9 ± 5 N.D. N.D. 22.2 ± 13 10 45
35 3.5 ± 1 N.D. N.D. 0.8 ± 0.6 1.9 ± 0.9 2.7 ± 1.5 N.D. 2.2 ± 0.8 1.1 ± 0.7 3.3 ± 2 N.D. N.D. 9.5 ± 4 28 35
N.D.: not detected, Grand total: the sum of concentration of all studied pesticide compounds, EOM: extractable organic matter, % C ¼ total cyclodienes/grand total, % D ¼ total DDTs/grand total.
Table 3 Average concentration of organochlorine (ng/g of wet weight) in fish collected from Port Said and Demietta Location Port Said (fish sample)
EOM (mg/g of wet wt.) HCB Lindane Heptachlor Heptachlor epoxide Dieldrin Total cyclodienes p,p0 -DDT p,p0 -DDE p,p0 -DDD Total DDTs Toxaphene Chlordane Grand total %C %D
Demietta (fish sample)
Bouri
Denis
Moza
Mousa
Bouri
Denis
Moza
Mousa
62 15.2 ± 7.4 10.1 ± 4.2 N.D. 4.7 ± 2.3 10.2 ± 4.9 14.9 ± 7 3.8 ± 2.6 21.5 ± 12.2 3.1 ± 2.4 28.4 ± 17 N.D. N.D. 68.6 ± 37 22 41
55 8.4 ± 3.3 N.D. N.D. 2.1 ± 1.1 6.3 ± 2.5 8.4 ± 3.4 2.2 ± 0.6 19.3 ± 11 2.1 ± 0.8 23.6 ± 12 N.D. N.D. 40.4 ± 19 21 58
38 5.4 ± 2.1 7.6 ± 4.1 N.D. 1.7 ± 0.8 2.5 ± 0.7 4.2 ± 1.5 N.D. 9.2 ± 5 N.D. 9.2 ± 4.6 N.D. N.D. 26.4 ± 12 16 35
42 2.5 ± 1.3 N.D. N.D. 0.4 ± 0.2 1.1 ± 0.3 1.5 ± 0.6 N.D. 4.8 ± 2.2 0.7 ± 0.3 5.5 ± 2.5 N.D. N.D. 9.5 ± 4.4 16 58
65 38.6 ± 16.3 30.2 ± 12.7 N.D. 9.4 ± 3.4 18.6 ± 7.6 28.0 ± 10.5 15.1 ± 6.6 50.4 ± 22.5 25.8 ± 17.4 91.3 ± 2.5 22.4 ± 16.3 N.D. 210.5 ± 11 13 43
60 17.4 ± 8.8 11.2 ± 8.1 N.D. 5.5 ± 2.2 9.4 ± 3.7 15.0 ± 6.8 8.7 ± 2.8 30.2 ± 12.2 8.3 ± 3.9 46.2 ± 19 10.2 ± 5.6 N.D. 101.9 ± 48 15 45
50 9.2 ± 3.6 7.4 ± 2.9 N.D. 2.1 ± 0.8 4.4 ± 1.4 6.5 ± 2 6.2 ± 2.5 10.3 ± 3.6 N.D. 16.5 ± 6 N.D. N.D. 39.6 ± 15 16 42
47 5.1 ± 3.1 N.D. N.D. 1.1 ± 0.5 N.D. 1.1 ± 0.5 1.2 ± 0.5 3.1 ± 1.1 4.1 ± 1.9 8.4 ± 4 3.5 ± 1.2 N.D. 18.1 ± 10 6 46
N.D.: not detected, Grand total: the sum of concentration of all studied pesticide compounds, EOM: extractable organic matter, % C ¼ total cyclodienes/grand total, % D: ¼ total DDTs/grand total.
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A. El Nemr, A.M.A. Abd-Allah / Chemosphere 54 (2004) 1401–1406 45
HCB
Lindane
Heptachlor Epoxide
Dieldrin
Concentration (ng/g)
40 35 30 25 20 15 10
Bouri
Moza
Denis
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
Demietta
0
Port Said
5
Mousa
Fig. 2. Average concentration of HCB, lindane, heptachlorepoxide and dieldrin.
60 p,p'-DDT
p,p'-DDE
p,p'-DDD
Toxaphene
40 30 20
Bouri
0
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
Moza
Denis 0
Port Said
Demietta
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
0
Port Said
10 Demietta
Concentration (ng/g)
50
Mousa 0
Fig. 3. Average concentration of p,p -DDT, p,p -DDE, p,p -DDD and toxaphene.
or near-bottom feeders. With respect to grand total values and as a general trend, fish from the Mediterranean Sea (Demietta and Port Said) were more polluted than that of Red Sea; see Table 2 (Suez and South Sinai). This may be due to the environmental conditions, level of exposure, nature of the pesticide, its solubility, the fish species, and its ability to excrete the compounds (Edwards, 1973). Moreover, grand total values indicated that the highest concentration occurred at Demietta (211 ng/g), followed by Port-Said, Suez and South Sinai. Toxaphene was detected only in fish from Demietta governorate (Bouri, Denis and Mousa). HCB was present in fish at each governorate except for Mousa from South Sinai. The highest concentration of total cyclodiene compounds (TCC) were found in Bouri fish from Demietta (28 ± 10.5 ng/g) which represented 13% of the grand total value and the highest percentage of TCC was re-
corded for Bouri fish collected from South Sinai (16.9 ± 8 ng/g, 31% of the grand total value). The highest concentration of total DDTs isomers were found in Bouri fish from Demietta (91.3 ± 2.5 ng/g) which represented 43% of the grand total value, whereas the highest percentage of DDT isomers was found in Mousa fish collected from South Sinai (7 ± 2.4 ng/g, represented 83% of the grand total value). p,p0 -DDE recorded the major concentration over all other DDTs in all studied fish (Tables 2 and 3). In some fish samples, from the South Sinai governorate the concentration of all the compounds were below the detection limit. The other fish contained various different levels of the residues. The highest value was found for p,p0 -DDE followed by HCB, except in Mousa fish samples (Figs. 2 and 3). However, the levels of organochlorine residues detected generally varied greatly. For instance, the minimum average value found
A. El Nemr, A.M.A. Abd-Allah / Chemosphere 54 (2004) 1401–1406
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Table 4 Range of chlorinated hydrocarbons in fish from other parts of the world (ng/g wet weight) Area
Fish
DDts
Dieldrin
Toxaphene
Chlordanes
References
Adriatic Italy USA (Fumee Lake) USA (Texas) USA (San Francisco Bay) Hong Kong
Various fishes Various fishes Smallmouth bass Various fishes Various fishes Tilapia
N.D.–569 12–86.1 138–587 76–2117 5.3–85 28-40.1
N.A. N.A. 26–80 <1–9 0.2–4.5 N.A.
N.A. N.A. 93–367 N.D.–312 N.A. N.A.
N.A. N.A. 43–243 <1–9 1.1–18 N.A.
Picer (2000) Picer (2000) Henry et al. (1998) Wainwright et al. (2001) Davis et al. (2002) Zhou et al. (1999)
N.D.: not detection; N.A.: not available.
for p,p0 -DDE was 5 ± 2 for Mousa fish and the maximum was 18 ± 11 ng/g for Bouri fish. The concentrations of organochlorine pesticides were present in the following descending order: HCB, p,p0 DDE, dieldrin and p,p0 -DDD in fish from Suez (Table 2). Heptachlor and chlordane were not detected in all studied fish from the four governorates. Toxaphene was detected only in studied fish from Demietta and the maximum toxaphene value was 22 ± 16 ng/g in Bouri fish (Table 3). This is the first record of toxaphene residues in Demietta governorate’s fish. All fish from Demietta governorate contained p,p0 -DDE as the predominate compound (50 ± 22 ng/g in Bouri fish) followed by HCB and lindane (Table 3). p,p0 -DDE was the predominate compound, followed by HCB, lindane, and dieldrin in fish samples from Port Said governorate (Table 3). Toxaphene is still manufactured and used in some east European countries, Mexico, Latin America, India and other developing countries. Therefore, it is suggested that the Global Environment Monitoring System (GEMS) established by UNEP, which includes Canada, USA, Egypt and 38 other participating countries, should consider toxaphene residues as one of the organochlorine pollutants for mandatory monitoring in imported and exported food materials (El-Sebae et al., 1993). The levels of pesticide residues differed greatly among the fish samples of the selected governorates. This may be due to the fact that the concentrations of organochlorine residues in fish depend on environmental conditions, levels of exposure and duration, nature of the pesticides and their solubility, fish feeding habitats and fish ability to excrete the compounds (Falandysz, 1985; Fowler et al., 1993). The concentration range of organochlorine in this study was lower than the range of the data obtained by Abdallah et al. (1990) from the same area. However, Abdallah et al. (1998) reported almost the same low levels of organochlorine compounds for the same area and same species. HCB occurs in the environment as a result of its wide range use as a fungicide and because it is a by-product of the manufacture of chlorinated hydrocarbons (Villanueva et al., 1974). Total DDTs concentrations recorded in this studied were lower than the concentration levels
reported for various fished from different parts from the world (Table 4). Dieldrin concentrations in this study were in the same level in fish from USA (Texas and San Francisco Bay) but much lower than the concentration level from USA (Fumee Lake) (Table 4). In some fish at Port Said (El-Dib and Badawy, 1985), the concentrations of HCB ranged from 0.1 to 18 ng/g, whereas in this study the concentrations of HCB at this same location ranged from 2 to 15 ng/g. The highest HCB levels occurred in Demietta’s Bouri (39 ± 16 ng/g). 4. Hazard levels Since organochlorine compounds pose a potential health hazard, the maximum permissible levels of toxic substances recommended for protection of aquatic biota have been published. The National Academy of Sciences and National Academy of Engineering (NAS-NAE, 1972) recommended limits of 1000 ng/g for total DDTs and 100 ng/g dieldrin, endrin, heptachlor, chlordane and toxaphene (all as weight concentrations in whole bodytissue). In Sweden, the recommended tolerance limits are 5000 ng/g for total DDTs, and 200 ng/g for HCB (Swedish Food Regulation, 1983). From a public heath standpoint, residue levels of organochlorines in all analyzed biota in this investigation are considerably lower than these tolerance levels. Moreover, Canadian tissue residue guidelines for the protection of wildlife consumers of aquatic biota recommended the tolerance limit to be 14 ng/g for total DDT and 6.3 ng/g for toxaphene (CCME, 2001). According to this tolerance, the levels of organochlorine pesticides in many fish in this study are too high for consumption. However, further monitoring of these contaminants in the aquatic ecosystem is recommended to insure the protection of food sources in Egypt. References Abdallah, A.M.A., Ali, H.A., 1994. Residue levels of chlorinated hydrocarbons compounds in fish from El-Max Bay and Maryut Lake, Alexandria, Egypt. Toxicol. Environ. Chem. 42, 107–114.
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Abdallah, A.M.A., Hassan, I.M., Nagib, M.M., Abddonia, M.A., 1990. Survey of residues of organochlorine pesticides in some marketable Egyptian fish. J. Assoc. Anal. Chem. 73, 502–508. Abdallah, A.M.A., Ali, H.A., El Sebae, A.H., 1998. Level of chlorinated hydrocarbons in a Teleost fish and a bivalve from the Egyptian mediterranean coast and Nile estuary. Z. Lebensm.––Unters. Forsch. A 206, 25–28. CCME, 2001. Canadian Council of Ministers of the Environment, 2001. Canadian tissue guidelines for the protection of wildlife consumers of aquatic biota: summary table. Updated, in: Canadian Environmental Quality Guidelines, 1999, Canadian Council of Ministers of the Environment, Winnipeg. Davis, J.A., May, M.D., Greenfield, B.K., Fairey, R., Roberts, C., Ichikawa, G., Stoelting, M.S., Becker, J.S., Tjeerdema, R.S., 2002. Contaminant concentrations in sport fish from San Francisco Bay, 1997. Mar. Pollut. Bull. 44, 1117–1129. Edwards, C.A., 1973. Pesticides in the Environment, 2nd ed. CRC Press, Cleveland, OH. p. 170. El-Dib, M.A., Badawy, M.I., 1985. Organochlorine insecticides and PCBs in water, sediment, and fish from the Mediterranean Sea. Bull. Environ. Contam. Toxicol. 34, 216–227. El-Sebae, A.H., Abou Zeid, M., Saleh, M.A., 1993. Status and environmental impact of toxaphene in the third world––a case study of African agriculture. Chemosphere 27, 2063–2072. Falandysz, J., 1985. Organochlorine pesticides and polychlorinated biphenyls in sprats from the Southern Baltic 1983. Z. Lebensm.––Unters. Forsch. 18, 370–374. Fowler, B., Hoover, D., Hamilton, C., 1993. The quantification of toxaphene in environmental samples. Chemosphere 27, 1891–1905.
Henry, K.S., Kannan, K., Nagy, B.W., Kevern, N.R., Zabik, M.J., Giesy, J.P., 1998. Concentrations and hazard assessment of organochlorine contaminants and mercury in smallmouth bass from a remote lake in the upper peninsula of Michigan. Arch. Environ. Contam. 34, 81–86. National Academy of Sciences and National Academy of Engineering (NAS-NAE), 1972. Section III Freshwater aquatic life and wildlife, water quality criteria. Ecol. Res. Serve. Environ., Washington, DC, 62 pp. Picer, M., 2000. DDTs and PCBs in the Adriatic Sea. Croatica Chem. Acta 73, 123–186. Swedish Food Regulations––Foreign substances in food, 1983. The National Food Administration SLVFS: 1. Villanueva, E.C., Jennings, R.W., Burse, V.W., Kimbrough, R.D., 1974. Evidence of chlorobenzo-p-dioxin and chlorodibenzofurans in hexachlorocamphenes (toxaphene) (PCC) in biological samples. Fresenius Z. Anal. Chem. 300, 387– 402. Wainwright, S.E., Mora, M.A., Sericano, J.L., Thomas, P., 2001. Chlorinated hydrocarbons and biomarkers of exposure in wading birds and fish of the lower Rio Grande Valley, Texas. Arch. Environ. Contam. Toxicol. 40, 101– 111. Yamashita, N., Urushigawa, Y., Masunaga, S., Walash, M.I., Miyazaki, A., 2000. Organochlorine pesticides in water, sediment and fish from the Nile River and Manzala Lake in Egypt. Int. J. Environ. Anal. Chem. 77, 289–303. Zhou, H.Y., Cheung, R.Y.H., Wong, M.H., 1999. Residues of organochlorines in sediments and Tilapia collected from inland water system of Hong Kong. Arch. Environ. Contam. Toxicol. 36, 424–431.
Organochlorine contamination in some marketable fish in Egypt Ahmed El Nemr *, Aly M.A. Abd-Allah National Institute of Oceanography and Fisheries, Janaklees, Kayet Bay, Alexandria, Egypt Received 5 March 2003; received in revised form 18 August 2003; accepted 10 October 2003
Abstract Ten organochlorine compounds were analyzed in four species of fish (Bouri Mugil spp., Denis Sparus auratus, Moza Boops boops and Mousa Pegusa lascaris), from four Egyptian governorates (South Sinai, Suez, Port-Said and Demietta). Although all fish studied are bottom or near-bottom feeders, remarkable variations between studied species were noticed. The grand total values recorded at the studied governorates were in descending order: Bouri > Denis > Moza > Mousa. The highest concentration of pesticides was recorded in Demietta governorate fish (20–211 ng/g of wet weight) and the p,p0 -DDE dominated over the other p,p0 -isomers in all studied fish, while dieldrin was the dominated in the studied cyclodiene compounds. However, hexachlorobenzene (HCB) occurred at all studied governorate fish except Mousa fish from South Sinai. Toxaphene was detected only in fish (Bouri, Denis, and Mousa) from Demietta governorate. Chlordane was not detected in any studied fish. The level of organochlorine pesticides contamination in fish from the studied governorates is relatively low and should not pose a health risk to consumers. 2003 Elsevier Ltd. All rights reserved. Keywords: Egypt; Organochlorine pesticides; Bouri; Denis; Moza; Mousa
1. Introduction In Egypt, organochlorine pesticides were used from the 1950s until 1981. This class of chemicals is characterized by persistence in the environment and the tendency to accumulate in aquatic organisms. Although Egypt is the largest pesticide market in Arabian countries and the fourth largest importer of pesticides among developing countries (Yamashita et al., 2000), there are no regular monitoring programs in Egypt for identification and determination of pesticides in the environment.
*
Corresponding author. Fax: +20-3-574-0944. E-mail address: [email protected] (A. El Nemr).
There are numerous reports on organochlorine residues in the Egyptian coastal marine environment, but not for toxaphene, which was heavily used in early 1960s (El-Dib and Badawy, 1985; Abdallah and Ali, 1994; Abdallah et al., 1998; Yamashita et al., 2000). El-Sebae et al. (1993) reported the heavy use of toxaphene (54,000 metric tons), endrin (10 500 metric tons) and DDT (13 500 metric tons). Toxaphene is a complex mixture of chlorinated terpenes, probably hepta-, octa-, and nonachlorobornanes with the analog (2-exo,3-endo,5-exo,6endo,8,8,9,10,10-nonachlorobornane) being used as a toxaphene marker in gas chromatography analysis. The purpose of the present study is to determine the levels of some organochlorine pesticides such as cyclodienes compounds (including heptachlor, heptachlor epoxide, and dieldrin), DDT’s isomers (including p,p0 isomers of DDT, DDE and DDD) and hexachlorobenzene (HCB), toxaphene, lindane and chlordane in different species (Bouri Mugil spp., Denis Sparus auratus,
0045-6535/$ - see front matter 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2003.10.041
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A. El Nemr, A.M.A. Abd-Allah / Chemosphere 54 (2004) 1401–1406
Table 1 Common and scientific names, food, weight, and length of fish samples surveyed from different Egyptian governorates (1: Demietta, 2: Port Said, 3: Suez and 4: South Sinai) Common
Length (cm)
Weight (g)
Food
Scientific name
Bouri Denis Moza Mousa
18.4–22.6 14.3–18.7 11.5–16.4 9.6–16.8
66.7–80.4 50.2–61.1 29.2–33.4 14.8–19.5
Algae, organic matter Molluscs, crustacea Sea weeds, sponges, small crustacea Small molluscs, worms and crustacea
Mugil spp. Sparus auratus Boops boops Pegusa lascaris
Moza Boops boops and Mousa Pegusa lascaris) from marketable Egyptian fish from the Demietta, Port Said (Mediterranean Sea), Suez and South Sinai (Red Sea) Governorates (Table 1).
2. Materials and methods Fish samples were collected from local fishermen at sites 1–4 in October 2001 (Fig. 1), and kept frozen )20 C prior to analysis. White tissues (muscle) were sampled by section from 10 individuals of each fish species and tissues of same species were mixed to make composite samples (two samples of each fish). From each composite sample, two replicates each 20 g, were taken and mixed with 60 g of anhydrous sodium sulphate for drying prior to Soxhlet extraction. Extraction with hexane (200 ml) was carried out for 8 h. The n-hexane extract was rotary evaporated at 35 C to 15 ml, and transferred into a Kuderna-Danish concentrator to reduce the volume to 5 ml. Lipid content was determined from 20 ml aliquots of the sample extracts that were allowed to evaporate until dry. The residue was redissolved in 1 ml of methylene chloride, 0.1 ml was placed on filter paper and evaporated, and the residual mate32°
Mediterranean Sea
1 Demietta
2
Port Said
31°
Cairo
30°
Suez
3
29° South Sinai 4
28°
Egypt
27°
26°
Saudi Arabia
Red Sea
29°
30°
31°
32°
33°
Fig. 1. Samples locations.
34°
35°
rials were weighed. The extract was further reduced to 1 ml under a gentle stream of pure nitrogen gas. The fractionation was done on a Florisil (20 g) column (activation of the florisil was achieved by heating at 130 C for 12 h followed by partially deactivated with 0.5% water by weight and stored in a tightly sealed glass jar with ground glass stopper and the mixture were allowed to equilibrate for one day before use. The first fraction, eluted by n-hexane (60 ml), contained HCB, heptachlor epoxide, dieldrin, and p,p0 -DDE. The second fraction (50 ml, n-hexane/methylene chloride, 70:30) contained DDD and DDT. The third fraction was eluted by nhexane/methylene chloride (1:1, 50 ml) and contained lindane and toxaphene. Each fraction was concentrated and injected into a Hewlett Packard 5980 series II highresolution gas chromatograph (Hewlett Packard, USA) equipped with a 63 Ni electron capture detector (ECD). A fused silica capillary column (50 m · 0.32 mm · 0.52 lm) coated with DB-1 (5% diphenyl and 95% dimethyl polysiloxane) was used for the quantification. The oven temperature was programmed from an initial temperature of 70 C (2 min hold) to 260 C at a rate of 3 C min1 and was then maintained at 260 C for 20 min. Injector and detector temperatures were maintained at 250 and 300 C, respectively. Helium was used as the carrier (1.5 ml min1 ) and nitrogen as the make-up (60 ml min1 ) gas. Concentrations of individually resolved peaks were summed to obtain the total organochlorine concentration. An equivalent mixture provided by Dr. Ehrenstorfer Laboratories (Augsburg, Germany) with known organochlorine composition and content was used as the standard. Organochlorine pesticides were quantified by matching individually resolved peak areas with the corresponding peak areas of the external standards (POC mixture provided by IAEA). To control the analytical reliability and evaluate recovery efficiency and accuracy of the results, two replicates were conducted on organochlorine compound reference materials SRM 1588 (Cod fish, provided by EIMP-IAEA) every six samples. The laboratory results showed that recovery efficiency ranged from 88% to 103% with a coefficient of variation (CV) of 9–17%. Compounds were identified by matching retention time against those of authentic standards. The detection limits were 0.3 ng/g for studied organochlorine compounds.
A. El Nemr, A.M.A. Abd-Allah / Chemosphere 54 (2004) 1401–1406
3. Results and discussion The analytical results are presented as ng/g of the wet weight in Tables 2 and 3. The highest levels of organochlorine pesticides were found in Bouri fish while the lowest levels were recorded in Mousa fish collected from
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all four governorates (Figs. 2 and 3). The total concentrations of the 10 organochlorine compounds were present in fish in the following descending order: Bouri > Denis > Moza > Mousa in all studied locations (Tables 2 and 3). There was remarkable variation among the species studied, although all studied fish are bottom
Table 2 Average concentration of organochlorine (ng/g of wet weight) in fish collected from South Sinai and Suez Location South Sinai (fish sample)
EOM (mg/g of wet wt.) HCB Lindane Heptachlor Heptachlor epoxide Dieldrin Total cyclodienes p,p0 -DDT p,p0 -DDE p,p0 -DDD Total DDTs Toxaphene Chlordane Grand total %C %D
Suez (fish sample)
Bouri
Denis
Moza
Mousa
Bouri
Denis
Moza
Mousa
77 20.3 ± 9.6 N.D. N.D. 3.6 ± 2.2 13.3 ± 5.7 16.9 ± 8 N.D. 18.2 ± 11.3 N.D. 18.2 ± 11.3 N.D. N.D. 55.4 ± 29 31 33
65 12.2 ± 4.4 2.1 ± 0.8 N.D. 5.4 ± 3.1 6.9 ± 4.8 14.4 ± 8 N.D. 11.3 ± 9.8 3.8 ± 2.3 15.1 ± 12 N.D. N.D. 41.7 ± 25 29 36
47 5.4 ± 1.9 N.D. N.D. 1.1 ± 0.4 3.3 ± 1.2 4.4 ± 16 1.1 ± 1.3 6.1 ± 1.2 N.D. 7.2 ± 3 N.D. N.D. 17.0 ± 6 26 42
33 N.D. N.D. N.D. 1.4 ± 0.6 N.D. 1.4 ± 0.6 1.5 ± 0.4 5.1 ± 2 0.5 ± 0.2 7.1 ± 2.4 N.D. N.D. 8.5 ± 3.0 17 83
54 33.8 ± 12.2 2.4 ± 2.1 N.D. 1.1 ± 0.4 7.7 ± 2.6 8.8 ± 3.0 5.2 ± 3.1 12.8 ± 9.4 3.2 ± 1.3 20.1 ± 14 N.D. N.D. 66.2 ± 31 13 30
45 20.1 ± 9.9 2.1 ± 1.7 N.D. 0.9 ± 0.3 3.5 ± 2.1 4.4 ± 2.4 1.1 ± 0.8 7.4 ± 2.4 3.1 ± 1.5 11.6 ± 5 N.D. N.D. 38.2 ± 19 12 30
39 10.2 ± 6 N.D. N.D. N.D. 2.1 ± 1.3 2.1 ± 1 N.D. 3.4 ± 2.1 6.5 ± 2.7 9.9 ± 5 N.D. N.D. 22.2 ± 13 10 45
35 3.5 ± 1 N.D. N.D. 0.8 ± 0.6 1.9 ± 0.9 2.7 ± 1.5 N.D. 2.2 ± 0.8 1.1 ± 0.7 3.3 ± 2 N.D. N.D. 9.5 ± 4 28 35
N.D.: not detected, Grand total: the sum of concentration of all studied pesticide compounds, EOM: extractable organic matter, % C ¼ total cyclodienes/grand total, % D ¼ total DDTs/grand total.
Table 3 Average concentration of organochlorine (ng/g of wet weight) in fish collected from Port Said and Demietta Location Port Said (fish sample)
EOM (mg/g of wet wt.) HCB Lindane Heptachlor Heptachlor epoxide Dieldrin Total cyclodienes p,p0 -DDT p,p0 -DDE p,p0 -DDD Total DDTs Toxaphene Chlordane Grand total %C %D
Demietta (fish sample)
Bouri
Denis
Moza
Mousa
Bouri
Denis
Moza
Mousa
62 15.2 ± 7.4 10.1 ± 4.2 N.D. 4.7 ± 2.3 10.2 ± 4.9 14.9 ± 7 3.8 ± 2.6 21.5 ± 12.2 3.1 ± 2.4 28.4 ± 17 N.D. N.D. 68.6 ± 37 22 41
55 8.4 ± 3.3 N.D. N.D. 2.1 ± 1.1 6.3 ± 2.5 8.4 ± 3.4 2.2 ± 0.6 19.3 ± 11 2.1 ± 0.8 23.6 ± 12 N.D. N.D. 40.4 ± 19 21 58
38 5.4 ± 2.1 7.6 ± 4.1 N.D. 1.7 ± 0.8 2.5 ± 0.7 4.2 ± 1.5 N.D. 9.2 ± 5 N.D. 9.2 ± 4.6 N.D. N.D. 26.4 ± 12 16 35
42 2.5 ± 1.3 N.D. N.D. 0.4 ± 0.2 1.1 ± 0.3 1.5 ± 0.6 N.D. 4.8 ± 2.2 0.7 ± 0.3 5.5 ± 2.5 N.D. N.D. 9.5 ± 4.4 16 58
65 38.6 ± 16.3 30.2 ± 12.7 N.D. 9.4 ± 3.4 18.6 ± 7.6 28.0 ± 10.5 15.1 ± 6.6 50.4 ± 22.5 25.8 ± 17.4 91.3 ± 2.5 22.4 ± 16.3 N.D. 210.5 ± 11 13 43
60 17.4 ± 8.8 11.2 ± 8.1 N.D. 5.5 ± 2.2 9.4 ± 3.7 15.0 ± 6.8 8.7 ± 2.8 30.2 ± 12.2 8.3 ± 3.9 46.2 ± 19 10.2 ± 5.6 N.D. 101.9 ± 48 15 45
50 9.2 ± 3.6 7.4 ± 2.9 N.D. 2.1 ± 0.8 4.4 ± 1.4 6.5 ± 2 6.2 ± 2.5 10.3 ± 3.6 N.D. 16.5 ± 6 N.D. N.D. 39.6 ± 15 16 42
47 5.1 ± 3.1 N.D. N.D. 1.1 ± 0.5 N.D. 1.1 ± 0.5 1.2 ± 0.5 3.1 ± 1.1 4.1 ± 1.9 8.4 ± 4 3.5 ± 1.2 N.D. 18.1 ± 10 6 46
N.D.: not detected, Grand total: the sum of concentration of all studied pesticide compounds, EOM: extractable organic matter, % C ¼ total cyclodienes/grand total, % D: ¼ total DDTs/grand total.
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A. El Nemr, A.M.A. Abd-Allah / Chemosphere 54 (2004) 1401–1406 45
HCB
Lindane
Heptachlor Epoxide
Dieldrin
Concentration (ng/g)
40 35 30 25 20 15 10
Bouri
Moza
Denis
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
Demietta
0
Port Said
5
Mousa
Fig. 2. Average concentration of HCB, lindane, heptachlorepoxide and dieldrin.
60 p,p'-DDT
p,p'-DDE
p,p'-DDD
Toxaphene
40 30 20
Bouri
0
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
Moza
Denis 0
Port Said
Demietta
S. Sinai
Suez
Port Said
Demietta
S. Sinai
Suez
0
Port Said
10 Demietta
Concentration (ng/g)
50
Mousa 0
Fig. 3. Average concentration of p,p -DDT, p,p -DDE, p,p -DDD and toxaphene.
or near-bottom feeders. With respect to grand total values and as a general trend, fish from the Mediterranean Sea (Demietta and Port Said) were more polluted than that of Red Sea; see Table 2 (Suez and South Sinai). This may be due to the environmental conditions, level of exposure, nature of the pesticide, its solubility, the fish species, and its ability to excrete the compounds (Edwards, 1973). Moreover, grand total values indicated that the highest concentration occurred at Demietta (211 ng/g), followed by Port-Said, Suez and South Sinai. Toxaphene was detected only in fish from Demietta governorate (Bouri, Denis and Mousa). HCB was present in fish at each governorate except for Mousa from South Sinai. The highest concentration of total cyclodiene compounds (TCC) were found in Bouri fish from Demietta (28 ± 10.5 ng/g) which represented 13% of the grand total value and the highest percentage of TCC was re-
corded for Bouri fish collected from South Sinai (16.9 ± 8 ng/g, 31% of the grand total value). The highest concentration of total DDTs isomers were found in Bouri fish from Demietta (91.3 ± 2.5 ng/g) which represented 43% of the grand total value, whereas the highest percentage of DDT isomers was found in Mousa fish collected from South Sinai (7 ± 2.4 ng/g, represented 83% of the grand total value). p,p0 -DDE recorded the major concentration over all other DDTs in all studied fish (Tables 2 and 3). In some fish samples, from the South Sinai governorate the concentration of all the compounds were below the detection limit. The other fish contained various different levels of the residues. The highest value was found for p,p0 -DDE followed by HCB, except in Mousa fish samples (Figs. 2 and 3). However, the levels of organochlorine residues detected generally varied greatly. For instance, the minimum average value found
A. El Nemr, A.M.A. Abd-Allah / Chemosphere 54 (2004) 1401–1406
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Table 4 Range of chlorinated hydrocarbons in fish from other parts of the world (ng/g wet weight) Area
Fish
DDts
Dieldrin
Toxaphene
Chlordanes
References
Adriatic Italy USA (Fumee Lake) USA (Texas) USA (San Francisco Bay) Hong Kong
Various fishes Various fishes Smallmouth bass Various fishes Various fishes Tilapia
N.D.–569 12–86.1 138–587 76–2117 5.3–85 28-40.1
N.A. N.A. 26–80 <1–9 0.2–4.5 N.A.
N.A. N.A. 93–367 N.D.–312 N.A. N.A.
N.A. N.A. 43–243 <1–9 1.1–18 N.A.
Picer (2000) Picer (2000) Henry et al. (1998) Wainwright et al. (2001) Davis et al. (2002) Zhou et al. (1999)
N.D.: not detection; N.A.: not available.
for p,p0 -DDE was 5 ± 2 for Mousa fish and the maximum was 18 ± 11 ng/g for Bouri fish. The concentrations of organochlorine pesticides were present in the following descending order: HCB, p,p0 DDE, dieldrin and p,p0 -DDD in fish from Suez (Table 2). Heptachlor and chlordane were not detected in all studied fish from the four governorates. Toxaphene was detected only in studied fish from Demietta and the maximum toxaphene value was 22 ± 16 ng/g in Bouri fish (Table 3). This is the first record of toxaphene residues in Demietta governorate’s fish. All fish from Demietta governorate contained p,p0 -DDE as the predominate compound (50 ± 22 ng/g in Bouri fish) followed by HCB and lindane (Table 3). p,p0 -DDE was the predominate compound, followed by HCB, lindane, and dieldrin in fish samples from Port Said governorate (Table 3). Toxaphene is still manufactured and used in some east European countries, Mexico, Latin America, India and other developing countries. Therefore, it is suggested that the Global Environment Monitoring System (GEMS) established by UNEP, which includes Canada, USA, Egypt and 38 other participating countries, should consider toxaphene residues as one of the organochlorine pollutants for mandatory monitoring in imported and exported food materials (El-Sebae et al., 1993). The levels of pesticide residues differed greatly among the fish samples of the selected governorates. This may be due to the fact that the concentrations of organochlorine residues in fish depend on environmental conditions, levels of exposure and duration, nature of the pesticides and their solubility, fish feeding habitats and fish ability to excrete the compounds (Falandysz, 1985; Fowler et al., 1993). The concentration range of organochlorine in this study was lower than the range of the data obtained by Abdallah et al. (1990) from the same area. However, Abdallah et al. (1998) reported almost the same low levels of organochlorine compounds for the same area and same species. HCB occurs in the environment as a result of its wide range use as a fungicide and because it is a by-product of the manufacture of chlorinated hydrocarbons (Villanueva et al., 1974). Total DDTs concentrations recorded in this studied were lower than the concentration levels
reported for various fished from different parts from the world (Table 4). Dieldrin concentrations in this study were in the same level in fish from USA (Texas and San Francisco Bay) but much lower than the concentration level from USA (Fumee Lake) (Table 4). In some fish at Port Said (El-Dib and Badawy, 1985), the concentrations of HCB ranged from 0.1 to 18 ng/g, whereas in this study the concentrations of HCB at this same location ranged from 2 to 15 ng/g. The highest HCB levels occurred in Demietta’s Bouri (39 ± 16 ng/g). 4. Hazard levels Since organochlorine compounds pose a potential health hazard, the maximum permissible levels of toxic substances recommended for protection of aquatic biota have been published. The National Academy of Sciences and National Academy of Engineering (NAS-NAE, 1972) recommended limits of 1000 ng/g for total DDTs and 100 ng/g dieldrin, endrin, heptachlor, chlordane and toxaphene (all as weight concentrations in whole bodytissue). In Sweden, the recommended tolerance limits are 5000 ng/g for total DDTs, and 200 ng/g for HCB (Swedish Food Regulation, 1983). From a public heath standpoint, residue levels of organochlorines in all analyzed biota in this investigation are considerably lower than these tolerance levels. Moreover, Canadian tissue residue guidelines for the protection of wildlife consumers of aquatic biota recommended the tolerance limit to be 14 ng/g for total DDT and 6.3 ng/g for toxaphene (CCME, 2001). According to this tolerance, the levels of organochlorine pesticides in many fish in this study are too high for consumption. However, further monitoring of these contaminants in the aquatic ecosystem is recommended to insure the protection of food sources in Egypt. References Abdallah, A.M.A., Ali, H.A., 1994. Residue levels of chlorinated hydrocarbons compounds in fish from El-Max Bay and Maryut Lake, Alexandria, Egypt. Toxicol. Environ. Chem. 42, 107–114.
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Henry, K.S., Kannan, K., Nagy, B.W., Kevern, N.R., Zabik, M.J., Giesy, J.P., 1998. Concentrations and hazard assessment of organochlorine contaminants and mercury in smallmouth bass from a remote lake in the upper peninsula of Michigan. Arch. Environ. Contam. 34, 81–86. National Academy of Sciences and National Academy of Engineering (NAS-NAE), 1972. Section III Freshwater aquatic life and wildlife, water quality criteria. Ecol. Res. Serve. Environ., Washington, DC, 62 pp. Picer, M., 2000. DDTs and PCBs in the Adriatic Sea. Croatica Chem. Acta 73, 123–186. Swedish Food Regulations––Foreign substances in food, 1983. The National Food Administration SLVFS: 1. Villanueva, E.C., Jennings, R.W., Burse, V.W., Kimbrough, R.D., 1974. Evidence of chlorobenzo-p-dioxin and chlorodibenzofurans in hexachlorocamphenes (toxaphene) (PCC) in biological samples. Fresenius Z. Anal. Chem. 300, 387– 402. Wainwright, S.E., Mora, M.A., Sericano, J.L., Thomas, P., 2001. Chlorinated hydrocarbons and biomarkers of exposure in wading birds and fish of the lower Rio Grande Valley, Texas. Arch. Environ. Contam. Toxicol. 40, 101– 111. Yamashita, N., Urushigawa, Y., Masunaga, S., Walash, M.I., Miyazaki, A., 2000. Organochlorine pesticides in water, sediment and fish from the Nile River and Manzala Lake in Egypt. Int. J. Environ. Anal. Chem. 77, 289–303. Zhou, H.Y., Cheung, R.Y.H., Wong, M.H., 1999. Residues of organochlorines in sediments and Tilapia collected from inland water system of Hong Kong. Arch. Environ. Contam. Toxicol. 36, 424–431.