Research Journal of Animal, Veterinary and Fishery Sciences ___________________________ ISSN 2320 – 6535 Vol. 1(5), 10-15, June (2013) Res. J. Animal, Veterinary and Fishery Sci. International Science Congress Association 10 Mammalian Feces as Bio-Indicator of Heavy Metal contamination in Bikaner Zoological Garden, Rajasthan, IndiaGupta Varsha JECRC University, Ramchandpura, Sitapura, Jaipur-302022, INDIAAvailable online at: www.isca.in Received 10th May 2013, revised 25th May 2013, accepted 15th June 2013Abstract Present study is an attempt to evaluate feces as bioindicator of heavy metal contamination in captive zoo mammals. This is a non-invasive technique to study gross exposure of metal pollution. Various metal contents in mammals of Bikaner (India) zoo were in the range of 58.4±3.14 (Cervus unicolor) to 1.82±0.96 (Panthera. tigris) ppm d/w. Cadmium was in range between 2.46±0.08 (Axis axis) to 0.41±0.03 (Macaca mulatta) ppm d/w. Chromium was in rage of 91.68±2.28 (Oryctolagus cuniculus) to 1.36± 0.36(Macaca mulatta) ppm d/w. Copper was in range between 22.82±2.18 (Panthera pardus) to 6.15±0.45 (Boselaphus tragocamelus). Whereas zinc was found in range of 35.6±1.35 (Canis aureus) to 8.15±0.45 (Boselaphus tragocamelus) ppm d/w. Analysis of feed and water along with the soil in cages which is receiving particulate air pollutants indicates that air pollution is the primary cause due to high density of traffic in the area. Keywords: Bioindicator, feces, heavy metals, wild mammals, zoological garden.Introduction All organisms modify their environment, and humans are no exception. As the human population has grown and the power of technology has expanded, the scope and nature of this modification has changed drastically. Until recently, the term “human-dominated ecosystems” would have elicited images of agricultural fields, pastures, or urban landscapes; now it applies with greater or lesser force to all of Earth. Heavy metals are metallic chemical elements that have a relatively high density and are toxic or poisonous at low concentrations. Excessive concentrations in biological systems are detrimental;destabilize ecosystems because of their bioaccumulation in organisms, and toxic effects on biota and even death in most living organisms. The bioaccumulation means an increase in the concentration of toxicant in biological organism over time, compared to the toxicant concentration in the environment. Biomonitors or indicators are any species that provides additional information about the health of an environment. Zoological gardens (zoos) are institutions or facilities in which animals are confined within enclosures, displayed to the public, and in which they may also be bred. The history of modern zoological gardens, however, started some 200 years ago with the creation of the first public zoological garden. Since that time, large numbers of zoological gardens have been established in all parts of the world. Globally, zoological gardens are known to offer great opportunities for entertainment and education, and to contribute to wildlife conservation and promote scientific research, especially for environmentalists and conservationists, as the rate of extinction of wild life increases. Most of the zoos which were once located on the outskirts of the cities and towns are now surrounded by human activities like vehicular traffic and industries. Some of the famous zoos like municipal corporation zoo at Ahmadabad and forest departmental at Ahmadabad have vehicular traffic too close to premises. All these activities result in heavy metal pollution, which may be adversely affect the health and wellbeing of the wild animals housed in such protected areas. Kota is known to be an industrial area. Bikaner zoo is located in the centre of city surrounded by urban localities by motorable roads on which vehicles are frequently plying. Rao Bikaji founded the exotic desert city of Bikaner in 1488. Bikaner zoo when established was located on outskirts, and is known as morden market. Public offices surround one of the sides. The tourist moving towards Junagargh fort move across the public park where the traffic density seems to be much higher. Death have been reported in captive wild animals including monkeys, bears, raccoons, armadillos etc. due to ingestion of lead containing paint3,4. Similar situation was also reported in domestic animals like dogs, cats, goats, cattle etc. Mammals near urban areas with dense vehicular traffic and also near metal mines and smelters had the highest burdens of lead. Various studies have been reported metal concentrations in wild mammals living in highly contaminated area near smelters, chlor-alkali plant8,9, verges of heavily-used highways10 and mines or mine waste sites11,12. Several methods were employed to assess and draw a concentration profile of a variety of pollutants that might reach the wildlife habitats and wildlife itself. In fact the human race in its selfish design has used wildlife species as biological indicators to study the ambient concentration of the toxicants in his own ecosystem, both urban Research Journal of Animal, Veterinary and Fishery Sciences ________________________________________ ISSN 2320 – 6535 Vol. 1(5), 10-15, June (2013) Res. J. Animal, Veterinary and Fishery Sci. International Science Congress Association 11 and industrial. However, mammals, which are much closer to human beings, are rarely used. Rats, captured from either side of the highways indicated that concentration of the lead in the body was directly proportional to the distance from the highway13. Guano was first used as bio-indicator in Bat for pesticidal pollution as well as mercury exposure14-16 and analysis cadmium in the feces of humans17. Concentration of cadmium, lead, zinc, copper were reported in the feces of deer killed near smelters to check the degree of metals pollution18. A study was done in wild herbivores housed in various protected areas of Rajasthan, India clearly suggests that herbivore feces can be used as a bio-indicator of heavy metals exposure19. Similarly, study was also done in mammalian fauna of Keoladeo National Park, Bharatpur20, Sariska Tiger Reserve, Alwar21, Desert National Park, Jaisalmer and Gajner Wildlife sanctuary, Bikaner of Western Rajasthan22, Jodhpur zoological garden23and Kota zoological garden24. Scat samples of the mammals, vegetation, and soil samples clearly indicate the extent to which the mammalian fauna is exposed to metal contamination. The method of killing or sacrificing animal is not ethically sound. It is a purely invasive method which is increasing biological poverty on the earth. So there is an urgent need to develop a non-invasive method for monitoring heavy metal exposure. In our study we use feces / scat / fecal matter as bio-indicator of heavy metal contamination in wild or captive zoo mammals. Methodology Sampling Procedure: Fresh scat samples of mammals housed in the animal section of Kota zoo, India, were collected from the cages with the help of zoo staff. Samples were brought to the laboratory and freeze dried. Scat samples were collected from the cases of following mammalian species; black buck (Antilope cervicapra, chinkara (Gazella gazelle, chital (Axis axis), nilgai (Boselaphus tragocamelus), sambar (Cervus unicolor), rhesus monkey (Macaca mulatta), bonnet monkey (Macaca radiate), Indian porcupine (Hystrix indica), rabbit (Oryctolagus cuniculus), sloth bear (Melurus ursinus), wild boar (Sus scrofa), hyena (Hynea hyena), jackal (Canis aureus), Asiatic lion (Panthera leo), tiger (Panthera tigris), panther (Panthera pardus). To ascertain the source of contamination water and food samples of this zoo were also collected. Another, suspected source of contamination was suspended particulate matter settling on the floor of cages, hence soil samples were also taken from cages of animals. Scat and soil samples were stored in the plastic zip lock bags and water samples in the sterilized plastic containers.Sample treatment: For analysis of sample 0.5 gm of dry scat / vegetation / feed / soil were weighed and taken in the hard Borosil glass tube. Concentrated nitric acid and perchloric acid were added to each sample in 4:1 ratio. Sample was kept in water bath for 5 to 6 hours or until it was digested completely and became clear. When the sample was clear 3 to 4 drops of (30%) were added to neutralize and to dissolve the fat. After cooling each sample was diluted upto 10 ml with deionized water and transferred to sterilized Borosil glass vial and stored at room temperature prior to analysis. Water samples were transferred into beakers, cleaned with double distilled and acidified distilled water, and concentrated keeping on a hot plate in a flame hood adding 12 to 15 ml of analytical grade HNO. The heating was continued till such time the sample became colorless and clean. However, samples were never allowed to dry completely. By and large, nitric acid alone was adequate for complete digestion of water samples. HClOwas added only to those samples which had high organic matter which were always treated in advance (pre-treated) with nitric acid before adding perchloric acid. If necessary, more HNOwas added and volume brought down to the lowest quantity (10 to 25 ml) before precipitation occurred. After completing the digestion, beakers were allowed to cool. Samples were diluted upto 10 ml with double distilled water. Analytical determination: Entire metal analysis was done by using GBC Advanta ver. 1.31 Atomic Absorption Spectrophotometer at 217 nm for lead, 228.9 nm for cadmium, 324.7 nm for copper, 213.9 nm for zinc and 357.9 nm for chromium. Results are presented in µg/g (ppm) dry weight and µg/ml (ppm) wet weight. Calculations: Metal concentration = Dilution factor Weight of sample Where, Dilution factor = 10, Dry weight of the sample= 0.5 gms Statistical analysis: The statistical calculations were based on Ipsen and Feigel’s25 method. The values are expressed as mean ± standard deviation (S.D.) as well as in standard error (S.E.). Results and Discussion Concentration of lead, cadmium, chromium, copper and zinc in scat / fecal matter was analysed for every mammalian species captivated in a similar environment of zoo. These results show a trend of variation in metal content according to the feeding habits as well as activity level of mammals. The mammals were categorized in three major groups i.e. herbivores that feed on green leaves (vegetation), vegetables, green grains, fruits, cereals, pulses etc., omnivores which feed on both vegetation and meat or fish and carnivores type which are fed meat and fish. Metals concentrations indicate gross exposure. The concentration of lead analyzed in fecal matter of captive zoo wild mammals was in the range of 58.4±3.14 (Cervus unicolor) to 1.82±0.96 (Panthera. tigris) ppm d/w. Cadmium was in range between 2.46±0.08 (Axis axis) to 0.41±0.03 Research Journal of Animal, Veterinary and Fishery Sciences ________________________________________ ISSN 2320 – 6535 Vol. 1(5), 10-15, June (2013) Res. J. Animal, Veterinary and Fishery Sci. International Science Congress Association 12 Macaca mulatta) ppm d/w. Chromium was in rage of 91.68±2.28 (Oryctolagus cuniculus) to 1.36± 0.36 (Macaca mulatta) ppm d/w. Copper was in range between 22.82±2.18 Panthera pardus) to 6.15±0.45 (Boselaphus tragocamelus). Whereas zinc was found in range of 35.6±1.35 (Canis aureus) to 8.15±0.45 (Boselaphus tragocamelus) ppm d/w (table 1). The background levels of lead, cadmium, chromium, copper and zinc in food were analysed. The feed of every mammalian species was analyzed and it was found that lead was present in each sample of food which was provided to zoo mammals (table 2). The concentration of lead was found in the range of 6.12 to 11.0 ppm d/w. Cadmium was found in range of 1.17 to 2.12 ppm d/w. The concentration of chromium was found in the range of 1.99 to 9.92 ppm d/w. Copper was analysed in the range of 12.15 to 21.9 ppm d/w. The concentration of zinc in feed samples was observed in the range of 10.19 to 20.15 ppm d/w. Table-1 Metal concentration in scat samples of wild mammals housed in Bikaner Zoological Garden, Rajasthan S.N. Species N Pb(ppm) S.E. Cd(ppm) Cr (ppm) Cu (ppm) Zn(ppm) Mean ± S.D. Mean ± S.D. S.E. Mean ± S.D. S.E. Mean ± S.D. S.E. Mean ± S.D. S.E. Scat of mammal 1 Antilope cervicapra 22 2.24 ± 1.19 0.378 1.09 ± 0.31 0.099 4.79 ± 1.69 1.19 8.83 ± 1.81 1.27 10.61 ± 1.98 0.30 2 Gazella gazelle12 16.6 ± 0.38 0.174 #2.46 ± 0.08 0.027 7.47 ± 1.01 0.714 14.54 ± 0.58 0.117 20.15 ± 1.13 0.18 3 Axis axis 22 5.2 ± 1.32 0.420 1.0 ± 0.11 0.034 10.17 ± 0.17 0.12 10.09 ± 1.23 0.869 19.83 ± 0.95 0.53 4 Boselaphus tragocamelus16 10.14 ± 0.87 0.277 1.72 ± 0.04 0.013 5.53 ± 1.43 1.01 *6.15 ± 0.45 0.318 *8.15 ± 0.45 0.81 5 Cervus unicolor 14 #58.4 ± 3.14 1.51 1.66 ± 0.36 0.011 13.53 ± 4.67 3.30 11.74 ± 1.01 0.981 10.98 ± 0.89 0.98 6 Macaca mulatta 9 5.2 ± 1.59 0.503 *0.41 ± 0.03 0.65 *1.36 ± 0.36 0.02 8.96 ± 0.64 0.452 17.15 ± 1.21 0.86 7 Macaca radiate 7 7.84 ± 1.94 1.06 0.74 ± 0.07 0.02 6.2 ± 1.26 0.305 16.66 ± 0.92 0.65 16.73 ± 1.25 0.89 8 Hystrix indica 12 3.09 ± 0.16 0.053 1.04 ± 0.21 0.06 18.53 ± 0.29 0.205 11.97 ± 0.71 0.528 17.70 ± 2.11 1.85 9 Oryctolagus cuniculus8 12.62 ± 2.94 0.932 1.01 ± 0.06 0.02 #91.68 ± 2.28 1.91 15.98 ± 0.78 0.551 12.25 ± 1.01 0.72 10 Melurus ursinus15 12.38 ± 4.95 1.568 0.63 ± 0.06 0.021 5.63 ± 1.75 1.23 8.58 ± 0.03 0.021 25.81 ± 0.32 0.28 11 Sus scrofa 10 17.6 ± 2.94 0.931 1.73 ± 0.186 0.059 63.83 ± 1.95 0.891 20.14 ± 0.75 0.325 15.10 ± 0.34 01.51 12 Hynea hyena 15 5.81 ± 2.41 0.761 0.97 ± 0.05 0.016 47.53 ± 1.53 0.915 15.66 ± 0.45 0.139 31.18 ± 1.09 0.31 13 Canis aureus 13 3.12 ± 0.73 0.231 0.62 ± 0.11 0.037 9.87 ± 1.87 0.971 21.66 ± 2.98 1.22 #35.6 ± 1.35 0.93 14 Panthera leo 16 2.6 ± 0.70 0.227 1.6 ± 0.047 0.014 17.8 ± 1.36 1.11 16.47 ± 0.98 0.742 29.81 ± 1.36 0.15 15 Panthera tigris11 *1.82 ± 0.96 0.306 2.15 ± 0.13 0.041 39.47 ± 1.93 1.038 18.93 ± 1.09 0.731 28.23 ± 1.05 0.90 16 Panthera pardus12 1.96 ± 1.42 0.450 1.73 ± 0.18 0.059 15.03 ± 0.19 0.134 #22.82 ± 2.18 1.54 35.16 ± 1.20 0.15 N = Number of samples, ND = Not detectable, * = Lowest mean values µg/g (ppm) Research Journal of Animal, Veterinary and Fishery Sciences ________________________________________ ISSN 2320 – 6535 Vol. 1(5), 10-15, June (2013) Res. J. Animal, Veterinary and Fishery Sci. International Science Congress Association 13 Table-2 Metal concentration in Feed, Soil and Water Samples from Bikaner Zoological Garden, Rajasthan S.N. Sources N Pb (ppm) Cd (ppm) Cr (ppm) Cu(ppm) Zn (ppm) I Food Mean ±S.D. S.E. Mean ±S.D. S.E. Mean ±S.D. S.E. Mean ±S.D. S.E. Mean±S.D. S.E. A Meat 12 8.98 ± 1.03 0.297 1.26 ±0.07 0.02 4.02 ±0.28 0.08 16.05 ±1.09 0.315 16.22 ±0.66 0.19 C Vegetation (Lucerne) 15 6.16 ±0.44 0.18 1.54 ±0.08 0.032 2.83 ±0.63 0.025 14.81 ±0.32 0.131 10.66 ±0.82 0.33 D Vegetables 10 #11.0 ±1.62 0.57 #2.12 ±0.076 0.026 3.65 ±0.13 0.02 #21.9 ±0.10 0.035 *10.19 ±1.90 0.67 E Fruits 9 *6.12 ±1.19 0.396 1.61 ±0.018 0.006 *1.99 ±0.17 0.056 *12.15 ±1.23 0.41 #20.15 ±2.05 0.68 F Cereals 19 7.36 ±0.64 0. 171 1.32 ±0.11 0.029 #9.92 ±0.14 0.03 13.98 ±0.46 0.122 16.88 ±0.91 0.24 G Pulses 11 9.69 ±1.52 0.481 *1.17 ±0.142 0.044 4.72 ±0.74 0.23 12.45 ±1.15 0.307 18.42 ±1.02 0.27 II Water i Herbivore Cage 7 ND - 0.61 ±0.25 0.091 5.28 ±0.1 0.037 8.15±1.35 0.511 ND - ii Carnivore Cage 5 ND - 1.37 ±0.81 0.331 9.73 ±1.83 0.75 10.99 ±1.05 0.430 ND - III Soil 30 8.36 ±1.90 0.508 1.06 ±0.093 0.024 7.63 ±1.69 0.451 10.02 ±0.08 0.021 13.72 ±0.35 0.093 N = Number of samples, ND = Not detectable, * = Lowest mean values µg/g (ppm), # = Highest mean values µg/g (ppm). The background level of lead, cadmium, chromium, copper and zinc in soil and water from herbivore as well as carnivore cages were also analysed. The concentration of lead in soil was found to be significantly high 8.36±1.90 ppm d/w. Water was found to have trace amount of lead contents i.e. not detectable. Cadmium concentration in soil and water significantly lower i.e. 1.06±0.093 ppm d/w and 0.61±0.25 (herbivore cages) to 1.37±0.81 (carnivores cages) ppm w/w. Chromium concentration in soil and water i.e. 7.63±1.69 and 5.28±0.17 (herbivore cages) 9.73±1.83 (carnivores cages) ppm w/w. Copper concentration of soil and water were found to be 10.02±0.08 ppm d/w and 8.15±1.35(herbivore cages) 10.99±1.05 (carnivores cages) ppm w/w. In case of soil and water zinc content was 13.72±0.35 ppm d/w and Not detected in herbivore as well as carnivore cages respectively. Lead, cadmium, chromium, copper and zinc concentration were found in considerable amount in the biological samples (fecal matter/ feed) and non-biological (soil/water) samples collected from Bikaner zoo. Concentration of metals in particularly in fecal matter samples from zoo is much higher than the wild animals like white tailed deer feeding near smelter26. Metal pollution in soils is derived mostly from atmospheric fallout, coal fly ash and bottom ash, urban refuse, animal wastes, and agricultural and food wastes27. Study of Bikaner zoo shows that a part of exposure of mammals is through food while the metals in water were in traces. Metal concentration in feces normally equals that in food28. Obviously the additional exposure was through plausible route of inhalation. The load of lead in fecal matter almost exceeded what is present in the food material. Bikaner zoo apparently is polluted one for a traffic density much higher close to the zoo. However, the food is comparatively less contaminated but higher concentration in soil is indicative of heavy deposition of particulate matter. Wild mammals housed in zoo have no choice but to inhale the automobile exhaust, being caged, all 24 hours. Soils receive potentially toxic elements from both natural and wide range of anthropogenic sources, including the weathering of primary minerals, mining, fossil fuel combustion, the metallurgical, electronic, and chemical industries, and waste disposal and automobile exhaust. Earlier studies have quantified deposition of metals in the vicinity of the highway or traffic dense area, either by measurement by dry depositions fluxes at various distances from road, or by calculating soil and vegetation concentrations and assuming that the soil acts as long term store, hence effectively integrating the deposition29,30. Lead concentrations as high as 6835, 1180 and 682 ppm dry weight have been reported in soil, vegetation and invertebrates, respectively31,30. Major sources of metals are irrigation water (when contaminated by sewage and industrial effluent), battery production, metal products, metal smelting, cable coating industries, brick kilns, automobile emissions, re-suspended road Research Journal of Animal, Veterinary and Fishery Sciences ________________________________________ ISSN 2320 – 6535 Vol. 1(5), 10-15, June (2013) Res. J. Animal, Veterinary and Fishery Sci. International Science Congress Association 14 dust and diesel generator sets32-35. Other sources can include unsafe or excessive application of pesticides, fungicides and fertilizers, and can also include sewage sludge36-39. Metals belong to the group of foreign materials that are excreted into bile and their ratio of concentration in bile verses plasma is greater than 1.0 and may be as high as 10 to 1000. Since liver is in a very advantageous position for removing toxic materials from blood after their absorption, it can prevent their distribution to other parts of the body. Furthermore, because the liver is the main site of biotransformation of toxic agents the metabolites may be excreted into bile40. Lead is absorbed in gastrointestinal tract by two steps process. It is first absorbed from lumen and then excreted into the intestinal fluid41. Upon oral ingestion about 5 to 10 % of lead is absorbed and usually less then 5% of what is absorbed is retained42. Thus about 99.5 % of total ingested lead is excreted through feces. Out of this 90% is coming out without being absorbed and 9.5% after being absorbed and metabolized leaving only 0.5% to be deposited in various body tissues. Fecal matter analysis method’s distinct advantages over tissue analysis are that the exposure can be measured on daily basis , it does not involve killing or even disturbing the wild mammals, it represents the metal eliminated which has been incorporated due to gross exposure (inhalation, ingestion or dermal exposure) in a locality. Thus, it can be concluded that wild mammals housed in Bikaner zoo are exposed to metallic pollution (air and water). Our study has firmly established the value of fecal matter analysis as bioindicator of heavy metal contamination. Thus analysis of scat has advantage that it indicates gross exposure, does not involve disturbing and killing the animals and monitoring of exposure to contamination at 24 hours intervals. The study can be further extended to free-ranging wild animal which are exposed to contaminants that are emitted by vehicles plying on roads within the protected areas. Conclusion Our study indicate that scat can be use as better bio-indicator than other methods and it clearly establishes as a non-invasive tool for assessing metal exposure in wild or captive zoo mammals. It helps to conserve the wildlife. Reference1.Alloway B.J. (ed), Heavy metals in soils, Blackie Academic & Professional, Glasgow-London, 339 (1990)2.IUDZG/CBSG of IUCN/SSC, Executive summary, The World Zoo Consevation Strategy: The role of the zoos and aquaria of the world in global conservation (Chicago Zoological Society, U.S.A, (1993)3.Hopkins A., Experimental lead poisoning in the baboon,Brit. J. Industr. Med., 27, 130-140 (1970) 4.Zook B.C., Sauer R.M. and Garner F.M., Lead poisoning in captive wild animals, J. Wildl. Dis., 8(3), 264-272, (1972) 5.Dollahite J.W., Younger L. and Crookshank H.R.,Chronic lead poisoning in horses, American Journal Veterinary Research,39(6), 961-964 (1978)6.Goldsmith C.D. and Scanlon P.F., Lead levels in small mammals and selected invertebrates associated with highways of different traffic densities, Bulletin of Environmental Contamination Toxicology, 17, 311-316 (1977)7.Beyer W.N., Pattee O.H., Sileo L., Hoffaman D.J. and Mulhem B.M., Metal contamination in wildlife living near two zinc smelters, Environmental Pollution Ser A.,33, 63-86 (1985)8.Dustman E.H., Stickel L.F. and Elder J.B., Mercury in wild animals from lake St. Clair. In Environmental mercury contamination, ed. by R. Hurtung and B.D. Dinman, 46-52, Ann Arbor, Mich., Ann Arbor Scince Publishers, (1972)9.Wren C.D., Probable case of mercury poisoning in a wild otter, Lutra Canadensis, in northern Ontario, Canadian Field-Naturalist,99, 112-114 (1985) 10.Clark D.R. Jr., Lead concentrations: bats vs terrestrial mammals collected near a major highway, EnvironmentalScience& Technology, , 338-341 (1979)11.Roberts R.D. and Johnson M.S., Dispersal of heavy metals from abandoned mine working and their transference through terrestrial food chains, Environmental Pollution, 16, 293-310 (1978)12.Andrew S.H., Johnson M.S. and Cooke J.A., Cadmium in small mammals from grassland established on metalliferous mine waste, Environmental Pollution Ser A,33, 153-162 1984)13.Way C.A. and Schroder G.D., Accumulation of lead and cadmium in wild population of the commensal rat, Rattus norvegegicus, Archives of Environmental Contamination and Toxicology, 11, 407-417 (1982)14.Reidinger R.F. Jr., Factors influencing Arizona bat population levels, Ph.D. Thesis, Univ. Arizona, Tucson, 172 (1972)15.Petit M.G. and Altenbach J.S., A chronological record of environmental chemicals from analysis of stratified vertebrate excretion deposited in a sheltered environment, Environmental Research 6 (3), 339-343 (1973)16.Clark D.R. Jr. Richard K.L.V. and Merlin D.T., Estimating pesticide burdens of bats from guano analysis, Bulletin of Environmental Contamination Toxicology, 29, 214-220 1982) 17.Kjellstrom T., Borg K. and Lind B., Cadmium in feces as an estimator of daily cadmium intake in Sweden, Environmental Research, 15, 242-251 (1978) Research Journal of Animal, Veterinary and Fishery Sciences ________________________________________ ISSN 2320 – 6535 Vol. 1(5), 10-15, June (2013) Res. J. Animal, Veterinary and Fishery Sci. International Science Congress Association 15 18.Sileo L. and Beyer W.N., Heavy metals in white-tailed deer living near a zinc smelter in Pennsylvania, Journal of Wildlife Diseases,21, 289-296 (1985)19.Gaumat V. and Bakre P.P.,Mammalian dung as a bioindicator of heavy metal contamination, Proceedings of Academy of Environmental Biology,7(1), 99-102 (1998)20.Gaumat V. and Bakre P.P., Metal contamination in mammalian fauna of Keoladeo National Park, Bharatpur (India), Environment and Agriculture: Biodiversity Agriculture and Pollution in South Asia, 577-580 (2001)21.Gupta V. and Bakre P.P., Metal contamination in mammalian fauna of Sariska tiger reserve, Alwar, India, Journal of Ecophysiology and Occupational Health,12, 43-48 (2012)22.Gupta V., Mammalian Scat as a Bio-indicator of Heavy Metals Contaminationin Western Rajasthan, India, International Journal of Scientific and Research Publications 2(12), 1-7 (2012) 23.Gupta V. and Bakre P.P., Exposure of Captive Wild Mammals to Heavy metals Contamination in Jodhpur Zoological Garden, Rajasthan, India, IOSR Journal of Environmental Science, Toxicology And Food Technology (IOSR-JESTFT), 2(3), 38-42 (2012)24.Gupta V., Exposure of Captive Wild Mammals in Kota Zoo India to Urban Air Pollution, Indian Journal of Applied Research, 3(3), 139-142 (2013) 25.Ipsen J. and Feigel P., In Bancrofts Introduction to Biostatistics. 2nd Ed. Harper and Row Publisher. Inc.; New York (1970)26.Nriagu J. O. (Ed.), Biogeochemistry of lead in the environment, Vols I & II. Amsterdam, Elsevier (1988)27.Leonzio C. and Massi A., Metal bio-monitoring in bird eggs : A critical experiment, Bulletin of Environmental Contamination Toxicology,43, 402-406 (1989) 28.Littele P. and Wiffen R.D., Emission and deposition of petrol engine exhaust Pb-I, Deposition of exhaust Pb to plant and soil surfaces, Atmospheric Environment, 11, 437 (1977)29.Littele P. and Wiffen R.D., Emission and deposition of lead from motor exhaust II, Airborne concentration, particle size and deposition of lead near motorways, Atmospheric Environment,12, 1331 (1978)30.Williamson P. and Evans P.R., Lead: Levels in roadside invertebrates and small mammals, Bulletin of Environmental Contamination Toxicology, , 280-288 (1972)31.Duffus J.H., Heavy metal– a meaningless term? Pure Appl Chem, 74,793–807 (2002)32.Sharma P. and Dubey R.S., Lead toxicity in plants, Braz. J. Plant Physiol., 17(1), 35–52 (2005) 33.Bragato C., Brix H. and Malagoli M., Accumulation of nutrients and heavy metals in Phragmites australis (Cav.) Trin. Ex. Steudel and Bolboschoenus maritimus (L.) Palla in a constructed wetland of the Venice lagoon watershed, Environ. Pollut., 144(3), 967-975 (2006)34.Madejón P., Murillo J.M., Maranon T., Espinar J.L. and Cabrera F., Accumulation of As, Cd and selected trace elements in tubers of Scirpus maritimus L. from Donana marshes (South Spain), Chemosphere, 64(5), 742-748(2006)35.Murthy S.D.S., Sabat S.C. and Mohanty P., Mercury induced inhibition of photo system 11 activity and changes in the emission of fluorescence from Phycobilisome in intact cells of the cyanobacterium Spiritina platensis, Plant Cell Physiol., 30, 1153-1157 (1989)36.Bart D. and Hartman J.M., The role of large rhizome dispersal and low salinity windows in the establishment of common reed, Phragmites australis, in salt marshes: new links to human activities, Estuaries, 26, 436-443 (2003)37.Silliman B.R., Bertness M.D., Shoreline development drives invasion of Phragmites australis and the loss of New England salt marsh plant diversity, Conser. Biol.,18, 1424-1434 (2004)38.Weis J.S. and Weis P., Metal uptake, transport and release by wetland plants: Implications for phytoremediation and restoration review, Environmental International, 30(5), 685–700 (2004) 39.Klaassen C.D., Biliary excretion of metals, Drug Metabolism Reviews,, 165-96 (1976)40.Sobel A.E., Gawron O. and Kramer B., Influences of vitamin D in experimental lead poisoning. Proceedings of the Society for Experimental Biology and Medicine, 38, 433-435 (1938)41.Goyer R.A.,Toxic effects of metals. In: casarett and Doull’s Toxicology. The Science of Poisons. (ed) Klaassen, C.D. 3rd Ed. Macmillan Publishing Company, 582-653(1986)