Journal of Biotechnology and Bioengineering Volume 2, Issue 2, 2018, PP 40-44

Toxicity Concerns of Hexavalent from Tannery Waste

Manikant Tripathi1*, Sudhir K. Upadhyay2, Mandeep Kaur3, Kuljeet Kaur3 1Centre of Excellence, Department of Microbiology, Dr. Ram Manohar Lohia Avadh University, U.P., India 2Department of Environmental Science, V.B.S. Purvanchal University, U.P., India 3Department of Agricultural Sciences, Khalsa College, Punjab *Corresponding Author: Manikant Tripathi, Centre of Excellence, Department of Microbiology, Dr. Ram Manohar Lohia Avadh University, U.P., India.

ABSTRACT Environmental pollution by toxic results largely from industrial activities, although sources such as agriculture and sewage disposal also contribute to some extent. Industrial wastewater discharged from tanneries contains hexavalent chromium and other toxic compounds. Chromium (VI) is soluble, toxic, mutagenic, teratogenic, and known to cause several adverse effects on human health. It can alter the genetic materials and cause . The occurs in humans because of environmental pollution through soil or water contamination or due to occupational and non-occupational exposure of heavy metals. Chromium (VI) is transported into the cells through transport mechanism. To meet the challenge of toxic chromium (VI) pollution in environment, several treatment technologies such as physical, chemical and biological have been employed. However, the unregulated treatment process for disposal of polluted effluent has led to contamination of biotic and abiotic components of the environment. Whereas, primarily using microorganisms offers a clean and cost effective technique for transforming toxic chromium (VI) into its non-toxic or less-toxic forms. Keywords: Bioremediation; Chromium (VI); Environment; Pollution; Toxicity

INTRODUCTION function, and impose an economic and public health burden. Industrial wastewater is heavily polluted with hazardous heavy metals that cause hazardous Chromium is a naturally occurring element effects to plants, animals and humans life. It is found in rocks, animals, plants, soil and in due to the bioaccumulation of such toxic heavy volcanic dust and gases. It exists in various metal in the aquatic life which is ultimately oxidation states ranging from +2 to +6. The transferred to human bodies through ecosystem most stable forms are Cr6+ and Cr3+, although (Garg et al. 2012). they significantly differ in biological, geochemical and toxicological properties (Garg Tanneries are one of the most polluting industries 6+ et al. 2012). In India, the standard limit for Cr mainly causing chromium pollution. In India, discharge in inland surface waters is 0.1 mg l-1 there are more than 2500 tanneries, and 80% of (Bhide et al. 1996). The permissible value them are engaged in chrome process -1 established by the U.S. EPA is 0.05 mg l . (Shukla et al. 2009). The tannery waste containing However, in trace quantities, chromium is an large quantity of organics and tannins is released essential nutrient for humans, setting such into the environment which causes soil and permissible limits is essential, because at water pollution along with serious threat to elevated levels Cr is toxic (Lee et al. 2008). aquatic life and human health. The high-exhaust chrome tanning method leads to wastewater Any industrial activity using metals has an levels of 500-1000 mg Cr6+ l-1 (Aravindhan et al. inherent problem of disposing metal-laden 2004). The discharge of toxic chromium waste. It is essential to realize that physical containing waste from leather industry has removal of metal from solution occurs only become a matter of prime concern and is listed as when it is appropriately immobilized. The priority pollutants by Environmental Protection procedure of metal removal from solutions often Agency (EPA) and World Health Organization leads to effective metal concentration. The (WHO). Metal pollutants affect ecosystem ultimate removal is attained only when the metal

Journal of Biotechnology and BioengineeringV2 ● I2 ● 2018 40 Toxicity Concerns of Hexavalent Chromium from Tannery Waste becomes concentrated to the point where it can interactions. Due of its structural similarity to 2- 2- be either returned to the process or resold. This sulfate (SO4 ), CrO4 , in some species crosses aspect of operation deals with the potential the cell membrane via the sulfate transport recovery of metal, which ideally should go system (Tripathi M, Ph.D. thesis 2013). hand-in-hand with the removal aspect. This Under normal physiological conditions, after makes the overall method an ultimately crossing the membrane Cr6+reacts spontaneously effective means for controlling the use of metals with intracellular reductants (e.g., ascorbate and by humans in technological procedure (Tripathi glutathione) to generate the short-lived M, Ph.D. thesis 2013). intermediates Cr5+ and/or Cr4+, free radicals and To meet the challenge of chromium pollution the end-product Cr3+. Cr5+ undergoes a one- resulting from tannery waste, a concerted effort electron redox cycle to regenerate Cr6+ by has been undertaken that involves both better transferring the electron oxygen. The process surveillance of chromium use, and improvements produces reactive oxygen species (ROS) that in in-plant and end-of-pipe treatment technologies. includes singlet oxygen (O) and superoxide Presently, 60% of tannery effluent generated in (O2−) (Cheng et al. 2010), hydroxyl (OH) and India is treated by 250 individual and 60 (H2O2) radicals that easily common-effluent treatment plants (Buljan and combine with DNA-protein complexes. Hence, Sahasranaman 1999). However, complete removal Cr4+ binds to cellular materials and deters their of chromium has not been achieved, and has normal physiological functions (Cervantes et al. evolved a new problem relating to safe disposal 2001). The genotoxic effect of Cr however of metal-laden sludge. Regions where treated cannot be fully explained by the sole action of effluent and sludge from treatment plants were ROS. Intracellular cationic Cr3+ complexes can disposed of onto arable land have resulted in a interact electro statically with negatively significant buildup of chromium content in the charged phosphate groups of DNA, which could soil. Chromium waste, when disposed of via affect replication, transcription and cause land application is also known to leach to mutagenesis (Cervantes et al. 2001). Cr3+ ground water (Sakthivel et al. 1999). The sludge interferes with DNA replication to produce an generated in these treatment plants is not safe increased rate of transcription errors in the cell's for land disposal due to the presence of high DNA. Additionally, Cr3+ may alter the structure levels of metals and the associated toxicity of and activity of enzymes by reacting with their their leachates (Srinath and Ramteke 1999), and carboxyl and groups (Cervantes et al. concern for metal species accumulation in plants 2001). (Barman et al. 2000). Effect of Occupational and non Occupational Toxicity of Chromium Exposure to Chromium Hexavalent chromium is toxic to most of the Cr6+ is highly mobile and water soluble, whereas plants at concentrations that vary from 5 to 100 Cr3+ is relatively inert, chemically more stable mg kg-1 of available chromium in soil. Because and less bioavailable due to its negligible of its high oxidizing potential, Cr6+ exhibits permeability to biomembranes (Pal et al 2005). mutagenic and carcinogenic effects on Cr6+ is nearly 100 times toxic (Garg et al. 2012) biological systems (Garg et al. 2012). The toxic and 1000 times more mutagenic than Cr3+ effects of Cr6+ are discussed here. (Barrera et al 2008). The toxicity occurs in humans due to environmental pollution via soil Genotoxic Effect or water contamination or due to occupational The toxic and mutagenic effects of chromium exposure. The causes serious have been reported to occur at concentrations morbidity and mortality. Even a slight elevation between 10-12 mg l-1, which are inhibitory to in the level of Cr6+ elicits environmental and most soil bacteria in liquid media. These effects health problems because of its high toxicity, are attributed to alteration of genetic material mutagenicity and carcinogenicity (Garg et al. and altered metabolic and physiological 2012). Soluble Cr6+ poses a significant reactions (Losi et al. 1994). Cr6+ does not carcinogenic risk if ingested. This is attributed interact directly with DNA and thus its to low pH of the stomach as particulate is attributed to its intracellular chromate dissolves at low pH (Holmes et al. reduction to Cr(III) via reactive intermediates. 2008). The toxic and mutagenic effects of The resulting types of DNA damage are chromium on microorganisms have been oxidative DNA damage, and Cr3+-DNA reported to occur at concentrations between 10-

41 Journal of Biotechnology and BioengineeringV2 ● I2 ● 2018 Toxicity Concerns of Hexavalent Chromium from Tannery Waste

12 mg l-1, which are inhibitory to most soil hepatotoxicity (Ueno 1992) in experimental bacteria in liquid media. These effects are animals causing DNA damage such as single attributed to alteration of genetic material and strand breaks and DNA-protein cross-links in altered metabolic and physiological reactions cultured and in vivo cells (de Flora et al. 1990). (Losi et al. 1994). Overexposure to Cr6+ reportedly produced allergic dermatitis, ulceration in the skin, Occupational exposure to chromium has been mucous membranes and nasal septum, renal identified as an important risk factor for human tubular necrosis and increased risk of respiratory . This metal also irritates airways, tract cancer (Flavio et al. 2004). Doses of Cr6+ causes nasal and skin ulcerations and lesions, -1 greater than 10 mg kg diet of humans affect causes perforation of the nasal septum, asthma, mainly the gastrointestinal tract, kidneys and dermatitis and other allergic reactions (Tripathi 6+ probably the hematopoetic system. Heavy M, Ph.D. thesis 2013). Ingesting Cr causes metals are predominantly present in many stomach and intestinal damage and can lead to 6+ industrial effluents along with other toxic cancer. In lab animals, Cr damages sperm and organic and inorganic compounds. In such male reproductive systems, and in some cases, environments they can exert toxicity in a has damaged the developing fetus (Tripathi M, complex manner. Binary mixtures of free Ph.D. thesis 2013). cyanide plus Cr6+ resulted in more fish lethality Nonoccupational exposure to the metal occurs than predicted by either response addition or via ingestion of chromium-containing food and concentration addition models (Leduc et al. water, whereas occupational exposure occurs 1982). 3+ via inhalation. Chromium is poorly absorbed, Mechanism of Cr6+ toxicity regardless of the route of exposure, whereas 6+ Hexavalent chromium is transported into cells Cr is more readily absorbed (Ray and Ray via the sulfate transport mechanisms, taking 2009). Humans as well as animals accumulate advantage of the similarity of sulfate and chromium in various locations such as lung, chromate with respect to their structure and liver, kidney, spleen, adrenals, plasma, bone charge. Under normal physiological conditions, marrow, red blood cells, etc. The respiratory and Cr6+ is believed to be reduced inside the cell dermal toxicity is well documented (Holmes et through reactive short-lived intermediates such al. 2008). as Cr5+ and/or Cr4+ free-radicals to the more 3+ Physiologically, Cr6+ is toxic due to its stable Cr (Xu et al. 2004; Pal et al. 2005; membrane permeabilty that results in the Cheung et al. 2006) by cellular reductants such functional change of the lung, respiratory tract, as glutathione, cysteine, ascorbic acid, liver, pancreas and kidney (Tripathi M., Ph.D. riboflavin, and NADH-dependent flavoenzymes thesis 2013). Gibb et al. (2000 a,b) reported such as microsomal cytochrome P450 reductase several ailments associated with Cr6+ exposure (de Flora et al. 1990; Sugiyama 1992). that include nasal irritation and ulceration, skin Therefore, the formation of paramagnetic 5+ irritation, eardrum perforation and lung species such as Cr might play an important carcinoma. Hexavalent chromium can role in the induction of the toxic properties of 6+ 6+ 5+ 5+ 4+ 3+ 2+ accumulate in the placenta thereby impairing Cr . Infact, Cr /Cr , Cr /Cr and Cr /Cr fetal development in mammals (Saxena et al. oxidation/reduction couples have been shown to 1990). In their study, Maria et al. (1999) found serve as cyclical electron donors in a Fenton- that workers exposed to tanning process had like reactions, which generate active oxygen several ailments pertaining to general health species such as hydroxyl radicals, that are diminishing. They were hypoglycaemia with known to produce a number of toxic effects respiratory cancer and nephrotic ailments. (Luo et al. 1996; Shi et al. 1999). Ueno et al. Epidemiological studies on industrial workers (2001) reported that hydroxyl radicals formed 6+ exposed to Cr6+ had a higher incidence of during Cr reduction may play an important respiratory than the normal population role in the DNA strand breaks caused by the 6+ (Norseth 1986; Langard 1990). Katz and Salem metals, and implied that the levels of Cr inside (1994) reported nasal mucous membrane the cells may not always be related to the perforation in exposed workers at tannery, induction of DNA strand breaks. galvanoplastic and chromate production units. CONCLUSIONS Additionally, renal and hepatic toxicity have been reported in workers exposed to Cr6+ Chromium (VI) is one of the major (Verschoor 1988), nephrotoxicity and environmental toxicants. The pollution of such

Journal of Biotechnology and BioengineeringV2 ● I2 ● 2018 42 Toxicity Concerns of Hexavalent Chromium from Tannery Waste toxic heavy metals pose adverse effects to human [12] Gibb HJ, Lees PS, Pinsky PF, Rooney BC health and ecosystem. Thus, detoxification of Cr (2000b) Clinical findings of irritation among (VI) is necessary before discharge in to the chromium chemical production workers. Am J environment. There must be proper cost Ind Med 38: 127-131. effective ecofriendly treatment technology to [13] Holmes AL, Wise SS, Wise Sr JP (2008) remove toxicity caused by Cr (VI) containing Carcinogenicity of hexavalent chromium. Indian J waste. Med Res 128: 353-372. [14] Katz SA, Salem H (1994) The Biological and REFERENCES Environmental Chemistry of Chromium. VCH [1] Aravindhan R, Balaraman M, Jonnalagadda Publishers Incorporation, New York. RR, Balachandran UN, Thirumalachari R (2004) [15] Langard S (1990) One hundred years of Bioaccumulation of chromium from tannery chromium and cancer: a review of wastewater: an approach for chromium recovery epidemiological evidence and selected case and reuse. Environ Sci Technol 38(1): 300-306. reports. Am J Ind Med 17: 189-215. [2] Barman SC, Sahu RK, Bhargava SK, Chaterjee C [16] Leduc G, Pierce RC, McCracken IR (1982) The (2000) Distribution of heavy metals in wheat, effects of cyanides on aquatic organisms with mustard, and weed grown in field irrigated with emphasis upon freshwater fishes. National industrial effluents. Bull Environ Contam Toxicol Research Council Canada, NRCC No 19246, p 64: 489-496. 139. [3] Barrera LM, Jimenez FMG, Moreno AO, Urbina [17] Lee SE, Lee JU, Chon HT, Lee JS (2008) EC (2008) Isolation, identification and Microbiological reduction of hexavalent characterization of a Hypocrea tawa strain with chromium by indigenous chromium-resistant high Cr (VI) reduction potential. Biochem Eng J bacteria in sand column experiments. Environ 40: 284–292. Geochem Health 30: 141-145. [4] Buljan J, Sahasranaman A (1999) Pollution [18] Losi ME, Amrhein C, Frankenberger WT (1994) Environmental biochemistry of chromium. Rev containment in the tanning industry in developing Environ Contam Toxicol 36: 91-121. countries. Proc. of XXV IULTCS Congress. Tata McGraw-Hill Publishers, New Delhi, pp 410-422. [19] Luo H, Lu Y, Mao Y, Shi X, Dalal NS (1996) Role of chromium (IV) in the chromium (VI)- [5] Cervantes C, Campos-Garica J, Gutierrez-Corona related free radical formation, dG hydroxylation, F, Loza-Tavera H, Torres-Guzman JC, Moreno- and DNA damage. J Inorg Biochem 64: 25-35. Sanchez R (2001) Interactions of chromium with microorganisms and plants. FEMS Microbiol Rev [20] Maria MV, Bertha AR, Carlos GSJ (1999) Health 25: 335-347. deterioration by chromium in workers of a tannery unit. Proc. XXV IULTCS Congress. Tata [6] Cheng Y, Yan F, Huang F, Chu W, Pan D, Chen McGraw-Hill Publishers, New Delhi, pp 725-730. Z, Zheng J, Yu M, Lin Z, Wu Z (2010) Bioremediation of Cr (VI) and immobilization as [21] Norseth T (1986) The carcinogenicity of Cr (III) by Ochrobactrum anthropi. Environ Sci chromium and its salts. Braz J Ind Med 43: 649- 651. Technol 44(16): 6357-6363. [22] Pal A, Dutta S, Paul AK (2005) Reduction of [7] Cheung KH, Lai HY, Gu JD (2006) Membrane- hexavalent chromium by cell-free extract of associated hexavalent chromium reductase of Bacillus sphaericus AND 303 isolated from Bacillus megaterium TKW3 with induced expression. J Microbiol Biotechnol 16: 855-862. serpentine soil. Curr Microbiol 66: 327-330. [8] de Flora S, Bangnasco M, Serra D, Zanacchi P [23] Ray (Arora) S, Ray MK (2009) Bioremediation of (1990) Genotoxicity of chromium compounds: a heavy metal toxicity-with special reference to review. Mutational Res 238: 99-172. chromium. Al Ameen J Med Sci 2(2): 57-63. [9] Flavio AO, Camargo C, Benedict O, Fatima M, [24] Sakthivel S, Civakaran J, Ramasamy K, Naidu R (1999) Impact of tannery effluent irrigation on Bento W, Frakenberger T (2004) Diversity of nd chromium-resistant bacteria isolated from soils soil, groundwater and tree growth. Proc. 2 contaminated with dichromate. Appl Soil Ecol 29: International Conference on Contaminants in the 193-202. Soil Environment in the Australasia-Pacific region. INSCR, New Delhi, India, pp 355-356. [10] Garg SK, Tripathi M, Srinath T (2012). Strategies for chromium bioremediation from tannery [25] Saxena DK, Murthy RC, Jain VK, Chandra SV effluent. Rev Environ Contam Toxicol 217: 75- (1990) Fetoplacental-maternal uptake of 140. hexavalent chromium administered orally in rats and mice. Bull Environ Contam Toxicol 45: 430- [11] Gibb HJ, Lees PS, Pinsky PF, Rooney BC 435. (2000a) Lung cancer among workers in chromium chemical production. Am J Ind Med [26] Shi X, Ding M, Ye J, Wang S, Leonard SS, Zang 38: 115-126. L, Castranova V, Vallyathan V, Chiu A, Dalal

43 Journal of Biotechnology and BioengineeringV2 ● I2 ● 2018 Toxicity Concerns of Hexavalent Chromium from Tannery Waste

NS, Liu K (1999) Cr (VI) causes activation of [30] Ueno S (1992) Protective effects of thiol nuclear transcription factor-Kb, DNA strand containing chelating agents against liver injury breaks and Dg hydroxylation via free radical induced by hexavalent chromium in mice. reactions. J Inorg Biochem 75: 37-44. Kitasato Arch Exp Med 65: 87-96. [27] Shukla OP, Rai UN, Dubey S (2009) Involvement [31] Ueno S, Kashimoto T, Susa N, Furukawa Y, Ishii and interaction of microbial communities in the M, Yokoi K, Yasuno M, Sasaki Y F, Ueda J-I, transformation and stabilization of chromium Nishimura Y, Sugiyama M (2001) Detection of during the composting of tannery effluent treated dichromate (VI)-induced DNA strand breaks and biomass of Vallisneria spiralis L. Biores Technol formation of paramagnetic chromium in multiple 100: 2198-2203. mouse organs. Toxicol Appl Pharmacol 170: 56- [28] Srinath T, Ramteke PW (1999) Heavy metals 62. contamination in sludge of tannery effluent [32] Verschoor MA, Braget PC, Herber RFM, Zielhuis treatment plants and their toxicity. Proc. 2nd RL, Zwennis WCM (1988) Renal function of International Conference on Contaminants in the chrome- workers and welders. Int Arch Soil Environment in the Australasia-Pacific Ocup Environ Health 60: 67-70. region. INSCR, New Delhi, India, pp 72-73. [33] Xu XR, Li HB, Gu J-D (2004) Reduction of [29] Sugiyama M (1992) Role of physiological hexavalent chromium by ascorbic acid in aqueous antioxidants in chromium (VI)-induced cellular solutions. Chemosphere 57: 609-613. injury. Free Radical Biol Med 12: 397-407. Tripathi M (2013) Ph.D. thesis "Simultaneous bioremediation of chromium (VI) and pentachlorophenol from tannery effluent" submitted to Dr. Ram Manohar Lohia Avadh University, Faizabad.

Journal of Biotechnology and BioengineeringV2 ● I2 ● 2018 44