Toxicological Characteristics of Leachate from Non-Sanitary Municipal Solid Waste Landfill

 

Suhendrayatna¹*, Luky Wahyu Sipahutar², Elvitriana³

¹Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

²Animal Science Department, University of Muhammadiyah Tapanuli Selatan, Indonesia.

³Environmental Engineering Department, University of Serambi Mekkah, Banda Aceh, Indonesia

 

ABSTRACT:

This research evaluated the toxicity and hepatotoxic effects of non-sanitary MSW landfill leachates on freshwater fish, Oreochromis niloticus. Toxicity test was conducted based on the OECD Guidelines for Testing of Chemicals. Fish was exposed to different leachate concentrations for 96 hours under static method. Acute mortality was closely monitored and analyzed using the Probit method. During the toxicity test, observations of fish test samples were performed on behaviour, mortality, and anatomical pathology. Results showed the content of ammonia, nitrate, sulphate, BOD, COD, and Zn in non-sanitary landfill leachate of Cot Padang Nila was found in high concentration. Against the leachate, freshwater fish, Oreochromis niloticus has acute mortality, LC₅₀ for 96 hours at the value of 20.172%. High mortality rate of fish was strongly influenced by the concentration level given (P<0.05). During the toxicity test, observations of fish behavioural changes showed symptoms of acute and sub-acute poison, including acceleration of operculum motion, hyperactivity, sudden jerks and loss of swimming power, and hyperpigmentation. Some fish organs undergo pathologic changes in the eyes, fins, scales, gills, and spleen. Histopathologically, gill tissue changes include epithelial release of lamella, hyperplasia, lamella fusion, and necrosis. The histopathologic features of liver show changes including fat degeneration, congestion, haemorrhage, inflammatory cell infiltration, and hepatocyte cell necrosis.

 

 

 

 

1. INTRODUCTION:

The most predominant method of domestic waste disposal in different parts of Indonesia is landfill. Municipal Solid Waste (MSW) landfill in Indonesia can be either sanitary or non-sanitary. The primary aim of sanitary landfilling is for safe long-term solid waste disposal with minimal health impact or environmental degradation^1,2. Unfortunately, numbers of landfills in Indonesia are non-sanitary, especially in the Aceh Province.

 

This draws critical attention to the use of liners in landfill for the purpose of enhancing easy collection of produced leachate and providing protection to groundwater. Landfills have been reported to release hazardous chemicals through gases and leachates into the environment

 

Leachate, as a complex mixture produced by the decomposition of wastes, contains inorganic macro-components, dissolved organic compounds, xenobiotic organic matters, and metals⁴. The leachate waters quantity formed in landfills depends mainly on the climatic factors in its vicinity. A landfill age also significantly affects the quality and quantity of leachate generated⁵. Leachate potentially pollutes the waters around the landfill and river. Leachate contamination in territorial waters will have a direct impact on aquatic biota. Pollution of water wells were reported in leachate from Gampong Jawa landfill in Banda Aceh and had an impact on the aquatic biota⁶, especially on fish and crab. Knowledge of the toxicity of leachates is necessary in determining raw leachate pollution effect on the environment and for health impact. The toxicity assessment of leachate is often difficult to assess due to its complex and highly variable composition and, it should be based not only on chemical assessment but the interactions among its chemicals or toxic degradation products with the biota⁷.

 

It has been reported that fresh water fish (Oreochromis niloticus) can withstand very polluted environment and even sewage sludge⁸ and has a fast rate of adaptation to environment. This research evaluated the toxicity and hepatotoxic effects of non-sanitary MSW landfill leachate on freshwater fish (Oreochromis niloticus). In this study, we investigated the toxic effects of MSW landfill leachates on the livers and gills of freshwater fish via its lethal dose concentration of leachate and its histopathology. Some physio-chemical parameters and metal ion composition of the leachate were also analysed.

 

2. MATERIALS AND METHOD:

2.1 Leachate collection and sampling site:

Cot Padang Nila MSW landfill in Pidie District, Aceh Province, Indonesia as a non-sanitary landfill was considered for this study. Leachate was collected from 3 leachate ponds in the landfill site and thoroughly mixed to provide a homogenous representative sample for each sampling site. This was then transferred to the laboratory in pre-cleaned 15 liter plastic containers, centrifuged at 3000 rpm for 10 minutes, filtered with glass wool and Whatmann® No. 42 filter paper to remove suspended particles, and stored at 4^oC as the stock sample (100%) until use.

 

2.2 Physico-chemical analysis of leachate:

Physical and chemical constituents of the leachate, such as ammonia, salinity, nitrate, sulphate, biochemical oxygen demand (BOD), chemical oxygen demand (COD), and pH, were analyzed according to APHA⁹. The concentrations of other metal ions, such as Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb), Nickel (Ni), Zinc (Zn), and Mercury (Hg), were determined according to APHA⁹ and USEPA¹⁰. Briefly, 100 ml of leachate was digested by heating with concentrated HNO₃. The resulting mixture was made up of 10 mL of 0.1 N HNO₃. The concentration of the metal was then analyzed using Shimadzu AA630 Atomic Absorption Spectrophotometer.

 

2.3 Toxicity test:

Freshwater fish species, Oreochromis niloticus obtained from stock culture of Jantho Fish Seed Breeding and Farming Center, Aceh Besar District, Indonesia was used as a test organism. In laboratory, fishes were allowed to acclimate in tap water at room temperature 30+2 ^oC during a light-to-dark cycle of 12:12 for at least two weeks before initiation of an in vivo test. Fish were fed twice a day with artificial food. Toxicity test was conducted based on the OECD Guidelines for Testing of Chemicals¹¹. Fish were exposed to different leachate concentrations for 96 hours with control condition under static method. The five leachate concentrations used were within the range of concentration 5%, 10%, 20%, 30%, and 100% v/v. Non-leachate was also prepared as control concentration (0% v/v). Ten fish (mean weight 80-100 g wet wt) were used for each designed concentration. Mortality was closely monitored and analyzed using the probit method supported by software MiniTab® 16 version; hence, LC₅₀ was generated for landfill leachate on the fish. During the toxicity test, observations of biota test sample were performed on behavior, mortality, and anatomical pathology.

 

Invitro test:

Both non-leachate and leachate exposed fishes were dissected after 96 hours to obtain fractions of gills and livers. Gill organs were fixed in 10% Davidson solution, whereas liver in 10% formalin solution. The gills were prepared for histological examination using Haematoxylin and Eosin staining technique. Tissue was viewed under light microscope while alternating the magnifications to obtain clear images.

 

3. RESULTS AND DISCUSSION:

3.1 Physico-chemical composition of non-sanitary MSW landfill leachate:

Table 1 shows the physico-chemical composition of non-sanitary MSW landfill leachate that was foul- smelling and characterized of black colour with value of 945.00 TCU. The colour of leachate reflects dissolved components of the waste and depends on the operational status of the landfill¹². pH leachate was found slightly alkaline with values of 7.95, and it implied that landfill was under methanogenic stage of degradation characterized of neutral pH. Therefore, the disparity in toxic impact on Oreochromis niloticus may be slightly linked to pH of leachate. Leachate produced from landfill is assumed to have undergone some stabilization¹³. Toxic impact from leachate can be associated to this because it is more neutral in pH. The neutral pH can combine with low redox potential to enhance the immobilization of metals ion via facilitation of metal hydroxides, sulphides, and complexes formation with organic compounds¹².

 

Table 1. Physico-chemical composition of leachate from non-sanitary landfill.

Characteristics	Value (Units)
pH	7.95
Salinity	3.1 o/oo
Color	945.0 TCU
Ammonia	76.23 mg/L
Nitrate (NO3-N)	12.0 mg/L
Sulphate (SO4)	130,0 mg/L
BOD	19.88 mg/L
COD	1215.97 mg/L
Cadmium (Cd)	<0,0012* mg/L
Chromium (Cr)	<0.00001* mg/L
Cupper (Cu)	<0.004* mg/L
Lead (Pb)	<0.0012* mg/L
Nickle (Ni)	<0.001* mg/L
Zinc (Zn)	0.0408 mg/L
Mercury (Hg)	<0.00001* mg/L

Note: * detection limit

The composition of chemical oxygen demand (COD), biochemical oxygen demand (BOD), sulphate, nitrate, ammonia, and Zn were higher compared to standard permissible limits. These high contaminants can affect the toxicity of leachate to environmental biota. Several studies reported that content of BOD, COD, ammonia-N¹³, and heavy metals, such as Zn¹⁴, may affect the behavior and physiological conditions of fish. With 19.88 mg/L BOD and 1215.97 mg/L COD for leachate, mortality and cellular impacts on Oreochromis niloticus might have been influenced by these two parameters. At such concentrations, oxygen depletion within an aquatic environment is possible. 

 

However, the degree of mortality exhibited by leachate may be attributed to the presence of ammonia. Result showed leachate recorded 12.0 mg/L of NH₃-N. A major potential impact of leachate when released to surface water is ammonia toxicity¹⁵. Since Cot Padang Nila Landfill is old (15 years operation), the tendency of nitrogenous compounds present in the landfill to continue degrading (releasing NH₃-N) is high, which is still receiving waste, and as such may not allow for faster degradation of such compounds.

 

Table 2. Mortality of freshwater fish (Oreochromis niloticus) during 96 h toxicity test

Leachate Concentration (v/v)	Repetition	Mortality during 1-96 h (No. fishes)							Mortality	Mortality (%)
		1	6	12	24	48	72	96
0% (control)	1 2 3	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0%
5%	1 2 3	0 0 0	0 0 0	0 0 0	1 1 1	1 0 1	1 1 1	1 0 1	4 2 4	33,3%
10%	1 2 3	0 0 0	0 0 0	1 1 0	2 0 0	0 2 3	1 1 0	1 0 1	5 4 4	43,3%
20%	1 2 3	0 0 0	0 0 0	1 0 1	3 2 0	0 1 2	1 1 1	0 2 1	5 6 5	53,3%
30%	1 2 3	0 0 0	0 1 0	1 0 1	2 2 0	2 2 2	2 1 1	0 0 1	7 6 5	60%
100%	1 2 3	0 0 0	5 3 1	5 5 4	- 2 5	- - -	- - -	- - -	10 10 10	100%

 

Figure 1. Linear regression probit model test, LC₅₀ leachate concentration to mortality of Freshwater fish, Oreochromis niloticus

 

3.2 Toxicity of Oreochromis niloticus against Leachate:

From this research, fish mortality is obtained during 96 hours of toxicity test with varying levels as tabulated in Table 2. The percentage of mortality in each leachate concentration treatment was found to vary (33.3%, 43.3%, 53.3%, 60%, and 100%), while no mortality was found in the control treatment (no leachate in this treatment).

 

This result shows the mean value of 50% (y) mortality percentage. The regression line lies at the point of 20.172 in the concentration line (x), where the measured log concentration ratio of mortality from each concentration is shown at red point 5%, 10%, 20%, and 30%, respectively. From this value, it was known that concentration level would be correlated with the number of fish mortality percentage. Higher leachate concentration given caused higher mortality of test fish. Higher concentration of leachate given in medium led the higher mortality of fish. Leachate impact on fish varied between landfills due to different leachate content. Leachate content is strongly influenced by type of landfill type, season, age of landfill, and garbage composition⁵. LC₅₀-96 hours of some leachates to fish have been reported as 14.97% for Putri Cempo Landfill¹⁶ and 3.83% for Malaysian Sedu Landfill River¹³. The low value of LC₅₀ will increase the toxicity level of the leachate.

 

3.3 Pathology changes:

During the toxicity test, observations of fish behavioral changes showed symptoms of acute and sub-acute poisoning, including acceleration of operculum motion, hyperactivity, sudden jerks and loss of swimming power, and hyperpigmentation. Observation of anatomy of organs showed the existence of some pathological symptoms of lesions to rupture on the fins and scales, mucus hyper-secretion on skin and gills, gill color pale, and eyes experiencing vaginal discharge with enlarged eye circumference. Observation of internal organs from each treatment group, showed anatomical pathology of the liver (Figure 3). Pathological changes in liver include hypertrophy, hyperemia, atrophy, and liver color changes. The description of anatomical pathological changes in freshwater fish Oreochromis niloticus after exposure to leachate is illustrated in Figures 2 and Figure 3.

 

Leachate contains toxic substances that can induce cytotoxic, oxidative stress, neurotoxins, and genotoxic that will affect some organs⁷. Fish poisoning was reported, leachate exhibit acute and chronic symptoms where fish will exhibit abnormal swimming patterns, difficulty breathing, sudden jerks, and excessive mucus secretions up to the physiological system damage¹³.

 

Figure 2. Freshwater fish (Oreochromis niloticus) before and after exposed to leachate (Note:  a. Rupture on the scales and fins, b. Lesions on the skin, c. Eye circle enlarged and anemic, d. Pale gill color)

 

Figure 3. The anatomical pathology of liver Oreochromis niloticus after exposure to various concentrations of leachate (Note: 1. Hyperemia, and liver atrophy; 2. Pale heart color, and hypertrophy)

 

Symptoms are also accompanied by pathological events in the eyes and gills¹⁷, the release of scales and discoloration on the surface of the body, and the blistering of scales and fins¹⁸. The leachate causes symptoms of neuro-toxin poisoning and results in changes in behavior and high mortality of fish was reported¹⁹. Pathologic liver damage can be caused by accumulation of leachate content in the liver. In acute or prolonged periods, the accumulation of toxic substances in fish body affects the liver, causing pathological conditions such as fatty, swelling, hyperemia, hemorrhage, necrosis, and may further undergo cirrhosis. The organic compounds and heavy metals are toxic substances in leachate²⁰, either individually or in combination. Fish will detoxify the toxin when the chemical content and heavy metals in water enter the body or the circulatory system. In long-term exposure or very high toxin content, the liver is not able to remove toxic substances that cause liver damage. In short exposure, the liver will also respond to contaminated environmental conditions by toxic substances but only limited pathological conditions that do not survive (deadly) such as fatty and swelling of the liver. However, this will cause the liver detoxification function not to be optimal²¹.

 

3.4 Histopathology of gills and liver:

The results of leachate toxicity test on fish showed changes in tissue and cell levels in the gills and liver. Histopathology of gill shows the release of epithelial cells in lamella gills, lamella cell hyperplasia, lamella fusion and necrosis, whereas the liver undergoes some degeneration of fat, congestion, hemorrhage, inflammatory cell infiltration, and hepatocyte cell necrosis. Histopathology changes of gill and liver in each treatment concentration are tabulated in Table 3 and Table 4.

Table 3. The histopathology observation of gills of freshwater fish Oreochromis niloticus on different concentrations of leachate.

Note: (-) none / not significant (normal); (+) damage less than 30% viewing area (light); (++) damage 30% -70% viewing area (medium); (+++) damage more than 70% of viewing area (weight)

 

Table 4. The results of observation on liver tissue of freshwater fish Oreochromis niloticus in various concentrations of leachate.

Concentration	Sample	Histopathology changes
		Fat Degeneration	Congestion	Hemorrhage	Infiltration of inflammatory cells	Necrosis
0%	1	-	-	-	-	-
	2	-	-	-	-	-
	3	-	-	-	-	-
5%	1	++	+	++	++	+
	2	++	+	+	++	+
	3	+	-	-	+	+
10%	1	++	+	++	+	+
	2	+	++	++	+	+
	3	++	+	+	+	++
20%	1	++	-	-	+	+
	2	++	+	+	+	++
	3	++	+	+	++	+++
30%	1	+++	+	+++	+	+
	2	++	++	+	++	++
	3	+	+	++	+	++
100%	1	+++	++	++	-	+
	2	+++	++	+++	-	++
	3	+++	++	+++	+	+++

Note: (-) none / not significant (normal); (+) damage less than 30% viewing area (light); (++) damage 30% -70% viewing area (medium); (+++) damage more than 70% of viewing area (weight)

 

 

Figure 5. Histopathological relationship of liver and leachate concentration level

 

Figure 6. Histopathological relationship of gill and leachate concentration level

 

From the observation of histopathology data in Table 3 and Table 4, statistical tests were performed to determine the correlation between concentration level and organ damage as a pollution indicator. Statistically, histopathology results of liver tissue damage level showed an insignificant relationship (P> 0.05) with leachate pollution. The result of correlation between leachate concentration level and liver tissue damage showed a relation between two variables of 0.108 (10.8%), whereas in gill, correlation and regression analysis showed a significant relationship (P <0.05), where the relationship between the two variables was 0.443 (44.3%). Relationship between the degree of tissue damage and leachate concentrations is presented in Figure 5 and Figure 6.

 

Figure 7. Histopathologic changes of the liver in various concentration treatments (Note : 0% concentration: liver was normal, 20% concentration has hemorrhage, fat degeneration, and hepatocyte necrosis, and 100% concentration liver has fatty).

 

Figure 8. Histopathological changes of gills in various concentration leachate (Note: (0%) normal, (10%) Experiencing the release of epithelial cells in the lamellae, (20%), Partial lamella fusion as well as hyperplasia, and (30%) fusion of lamella and necrosis.

 

The histopathology of the gills and liver in each treatment showed varying degrees of damage ranging from light to medium weight damage levels. The various degrees of damage can be seen in Figures 7 and 8. Based on statistically severe levels of gill and liver damage, gill organs are at greater risk due to its activity, which is directly exposed to water phase. Higher concentration of contaminants in leachate resulted in more severe damage that occurs in the gills. High mortality of fish in the early exposure phase was also strongly related to gill organ damage. In the liver, fish mortality was more dominant due to the effects of toxins that lasted relatively long, especially in low concentration exposure. Histopathologically, the risk that can kill fish shows severe damage, namely cell death (necrosis).

 

In histopathology, acute mortality with high concentrations indicate damage to the liver tissue that is lightly characterized by fatty degeneration, as well as congestion and hemorrhage. Fat degradation of the liver anatomically is characterized by swelling and change of liver color to yellowish white. This condition is classified as a medium degree of damage because it is reversible but can cause cellular injury and more caution to cause cell death (necrosis), which is severe damage. The death of these cells can be triggered by the presence of fat deposited in large quantities and continues to increase, thereby suppressing metabolism and oxygen exchange at the cellular level.

 

Damage that occurs in histopathology of gills can be an important indicator of poor water quality in the environment due to contamination. Significant pathological changes, such as epithelial damage, hyperplasia, lamella fusion, and necrosis of the gills, in this study were strongly associated with the content of contaminants in leachate water (Ammonia, Nitrate, Sulphate, BOD, COD, and Zn). Histopathologic gill changes caused by direct exposure to contaminants include ammonia²², Zn (zinc)²³, some other heavy metals²⁴; BOD-COD and bacterial toxins of leachate pathogens ²⁰ may cause histopathologic damage to the gills. Pollutants from leachate may cause higher mucus secretion, causing further pathological damage to the gill²⁴. Gills are important biomarkers in response to environmental conditions²⁵. When water becomes polluted, the gills will get the first impact of the contamination.

 

4. CONCLUSION:

The content of ammonia, nitrate, sulphate, BOD, COD, and Zn (zinc) in non-sanitary landfill leachate of Cot Padang Nila showed in high concentration. Against the leachate, freshwater fish Oreochromis niloticus has acute mortality LC₅₀ for 96 hours at value 20.172%. High mortality rate of fish was strongly influenced by the concentration level given (P <0.05). During the toxicity test, observations of fish behavioral changes showed symptoms of acute and sub-acute poisoning, including acceleration of operculum motion, hyperactivity, sudden jerks and loss of swimming power, and hyperpigmentation. Some fish organs undergo pathologic changes, including the eyes, fins, scales, gills, and spleen. Histopathological gill tissue changes include epithelial release of lamella, hyperplasia, lamella fusion, and necrosis. The histopathologic features of liver show changes including fat degeneration, congestion, hemorrhage, inflammatory cell infiltration, and hepatocyte cell necrosis.

 

5. REFERENCES:

1.     Agamuthu P, Fauziah SH and Emenike C.U., 2011, Waste Management in Asia: The Associated Toxicity. Proceedings of 3rd International Conference on Ecotoxicology and Environmental Sci-ences. Panaji, Goa, India, Nov 28-30 2011.

2.     Shekdar, A.V (2009). Sustainable Waste Management: An integrated approach for Asian countries. Waste Management, 29, Issue 4 pp 1438 – 1448.

3.     Alimba, C.G, Bakare, A.A, and Aina, O.O., 2012, Liver and Kidney Dysfunction in Wistar Rats Exposed to Municipal Landfill Leachate, Resources and Environment 2012, 2(4): 150-163 DOI: 10.5923/j.re.20120204.04.

4.     Christensen, T.H., Kjeldsen, P., Bjerg, P.L., Jensen, D.L., Christensen, J.B., Baun, A., Albrechtsen, H., Heron, G., 2001. Biochemistry of landfill leachate plumes. Appl. Geochem. 16, 659–718.

5.     Słomczyńska, B, and Słomczyński, T., Physico-Chemical and Toxicological Characteristics of Leachates from MSW Landfills, Polish Journal of Environmental Studies Vol. 13, No. 6 (2004), 627-637.

6.     Suhendrayatna dan Zurrahman (2009), The chemical water quality of residence well around Gampong Jawa landfill, Banda Aceh, Journal of Environmental, Vol. 1, No. 2, ISSN : 1412-7709.

7.     Tsarpali, V., dan S. Dailianis. (2012). Investigation of landfill leachate toxic potency: An integrated approach with the use of stress indices in tissues of mussels. J. Aquat. Toxicol. (125): 58-65.

8.     Hanna, M.I., El-Maedawy, S.A,  Kenawy, A.M, and Girgis, S.M., 2013, Sublethal Effects of Acute Ammonia Exposure on Oreochromis niloticus, Global Veterinaria 11 (5): 592-603, 2013 ISSN 1992-6197, © IDOSI Publications, 2013, DOI: 10.5829/idosi.gv.2013.11.5.8111

9.     APHA – American Public Health Association. Standard Methods for the Examination of Water and Wastewater, 20th ed. Washington, DC: American Public Health Association (APHA, AWWA, WPCF); 1998.

10.   USEPA – United States Environmental Protection Agency. Acid digestion of sediments sludges and soils, Method-3050B.USEPA: Washington, DC; 1996.

11.   OECD, 1998, OECD Guidelines for Test of Chemical, USA.

12.   Lagerkvist, A. (2003) Landfill Technology Technical Report. Department of Environmental Engineering. Division of Waste Science and Technology, Lulea University of Technology.

13.   Jaffar, Y., Lee Y and Salmijah, S, (2009). Toxicity Testing and the effect of landfill leachate in Malaysia on Behaviour of Common Carp (Cyprinus carpio L., 1758; Pisces, Cyprinidae). American Journal of Environmental Sciences, 5 (3): 209-217.

14.   Celik, E.S., Hasan, K., Sevdan, Y., Mehmet, A., dan Arinc, T. 2013. Effects of zinc exposure on the accumulation, haematology and immunology of Mozambique tilapia, (Oreochromis mossambicus). African Journal of Biotechnology. 12 (7): 744-753.

15.   Kjeldsen, P., M.A. Barlaz, A.P. Rooker, A. Baun, A. Ledin and T.H. Christensen, (2002). Present and long-term composition of MSW landfill leachate. Critical Reviews in  Environmental  Science and Technology., 32: 297-336. Doi: 10.1080/10643380290813462.

16.   Astuti, D. Sarto, dan S. Irawati. 2010. Penurunan toksisitas leachate (Air lindi) dari TPAS Putri Cempo Mojosongo Surakarta dengan PAC (Poly Aliminium Chloride). J. Manusia dan Lingkungan. Vol 7 (1):11-25.

17.   Galarpe, V.R.K., J.P. Aruta, D. Badilla., M.K. Lawas, dan M.A.O. Velez. (2014). Preliminary study on the effects of landfill leachate to Tilapia fingerlings. J. Appl. Sci. Environ. Sanit. (9): 163-168.

18.   Wesen, P., F. Rosariawari, dan F. Arie. (2009). Mujair sebagai bio-assesment terhadap toksisitas pada kandungan lindi di lahan pembuangan akhir Benowo, Surabaya. J. Ilmiah Teknik Lingkungan. 2 (1): 74-79.

19.   Emenike, C.U., S.H. Fauziah, and P. Agamuthu. (2012). Characterization and toxicological evaluation of leachate from closed sanitary landfill. J. Waste. Manag. Res. (30): 889-897.

20.   Oshode, O.A., A.A. Bakare, A. Adeogun, M, Efuntoye, dan A.A. Sowunmi. (2008). Ecotoxicological assessment using Clarias Gariepinus and microbial characterization of leachate from municipal solid waste landfill. Int. J. Environ. Res. 2 (4): 391-400.

21.   Triadayani, A.E., A. Riris, dan D. Gusti. (2010). Pengaruh logam timbal (Pb) terhadap jaringan hati ikan Kerapu Bebek (Cromileptes altivelis). Maspari Journal. 1 (1): 42-47 (Idonesian).

22.   Benli, A.C.K., dan G. Koksal. (2005). The acute toxicity of ammonia on Tilapia (Oreochromis niloticus L.) larvae and fingerlings. Turk. J. Vet. Anim. Sci. (29): 339-344.

23.   Abdel-Warith, A. A., E.M.Younis, N.A. Al-Asgah, dan O.M. Wahbi. (2011). Effect of zinc toxicity on liver histology of Nile tilapia, Oreochromis niloticus. Scientific Research and Essays. 6 (17): 3760-3769.

24.   Sivakumar, R., S. Sukumar, dan N. Munuswamy. (2014). Biomarkers of selected heavy metal toxicity and histology of Chanos chanos from Kaattuppalli Island, Chennai, southeast coast of India. J. Environ. Earth. Sci. (72): 207-219.

25.   Oliveira, L.F, Silva, S.M.C.P, and Martinez, C.B.R., 2014, Assessment of domestic landfill leachate toxicity to the Asian clam Corbicula fluminea via biomarkers, Ecotoxicology and Environmental Safety 103 (2014) 17–23.

 

 

 

 

Accepted on 15.05.2019          © RJPT All right reserved

Research J. Pharm. and Tech 2019; 12(9):4209-4215.