Ordinary Toxicity of Chlorine Dioxide and By-products Chlorite and Chlorate in Water

108Journal of Donghua University ( Eng. Ed. ) Vol.20, No.3 (2003)Ordinary Toxicity of Chlorine Dioxide and By-products Chlorite andChlorate in WaterWANG Li(王丽)’CHANG Ai-min(常爱敏)’HUANG Jun-li(黄君礼)1 Shenshem Water Qualiry Center, Shenshen, 5180012 lrbin Instiue of Technology, School of Ertironmenual Engineering. Harbin, 15000Acute toxicity and accumulated toxicity of chlorinefemale rats drink the water with high CIO2 concentration, theirdioxide ( ClO;) and by-products chlorite ( Cl0; ) andbaby weight are low and some dead fetuses6!. In addition,chlorate (CIO; ) in water acted on mice are studiedreports say hat drinking the mixed liquid with high CIO2 andby the method of Horn and accumulation coefficient.CIO; concentration exerts influence on blood and serum'"]Subchronic toxicity of the mixture of CIO, and CIO;Based on research done presently, the ordinary toxicity ofand C10; in water acted on rat is studied thoughCIO3, CIO2，CIO; and mixed aqueous soluion of CIO2 arefeeding test for 90 days, including statistical analysistested in this paper, including acute toxicity and cumulatedof variance on weight gaining， food uuilizationtoxicity of aqueous solution of CIO2, CIO2 , CIO; and mixedefficiency，index of blood and serum, liver ( or kidney)aqueous solution of CIO2; toxic injury 0n rats drinking heto body weight ratio, and histopathological examinationmixed solution of CIO2 and its by-products CIO; and CIO; foron liver and kidney. The results show that aqueousa relatively long period (90tays)，during the 90days feeding,solution of CIO2， NaCl02 and NaCl0, ( with theweight gain, food utilization effciency, index of blood andconcentration of 276.5 mg/L, 200 mg/L and 200 mg/Lserum, liver ( kidney)/weight and liver ( kidney) of the ratsrespectively) and the mixed aqueous solution of CO,have been histopathologically exanined. This study provideswith the concentration of 553 mg/L are actually non-poisonous, and non. cumulative aqueous solution as well.signifcant sanitary toxicological data for using CIO2 toKeywords : Chlorine dioxide , chorite ，chlorate ，toxicity, roaterdisinfect drinking water.Materials and MethodsIntroduction1 ReagentsChlorine dioxide(CIO2) as a disinfectant for potableC102: made by ouselves, generated by chemical way,water doesn'l react with precursors such as humic and fulvicpurity is higher than 98% .acids etc. to form haloformetl, it is a disinfectant better thanNaCIO2 aqucous solution: commrially pure NaClO2 isliquid chlorine to kill bactenia and viruses!2.1l, but CIO,dissolved in distiled water and reaches saturation, and filtered,produces 2 kinds of inorganic by products- -chlorite( CIO2 )then rerystalized under the irradiation of infrared light withand chlorate( CIO; ) during the disinfection process;the temperature lower than 40 C until its purity reaches 95%and higher. Keeping afer dried. Making up the NaClO2CIO2 +e"= CI0;CIO2 + 4H*+4e" = CI0;solution with desired concentration when it is used. Thissolution is colorless and transparent.occurred simultaneously, during water treatment process, someNaCIO, aqueous soluion; colorless and transparent. A. R70% of the CIO2 in the reaction take forms of CIO2 andgrand.chloride to be left over immediately, the CIO; is formned onlMixed liquid of CIO2: Total concentation of C102,under condition of high pH or in existence of hypochlorousCIO; and CIO; is 53 mg/L, the ratio is 5:3:2, ie.acidl*. Just because the disfection by CIO2 is accompaniedby the formation of CIO; and CIO; ，therefore, whenconcentration of C1O2, CI02 and CIO, are 276. 5 mg/L,165. 9mg/L and 110. 6 mg/L respectively. This solution isevaluating the safety of CIO2 used as dsisfecant for drinkingyellowish and transparent.water, the toxicity of CIO2 and CIO; should be taken under2 Test animalsconsideration. Results of engineering operation show that whentotal concentration of CIO2 and its by-products is 0.5 mg/L,mice and rats, Kunming species.the effluent can meet National standard for drinking water-'3 Test methodForeign experts have done researches on the toxicity of(1) Detcrmination of CO,， NacClO, and NaClO3:CIO2 and its by-products CIO2 and CIO; ，for example,continuous iodimnetry[&I.Received Jan. 21, 2002Corepondence should be adresed to WANC Li. , Dr. ，Email: wengixi中国煤化工:fYHCNMHGJournal of Donghua University (Eng. Ed.) Vol.20, No.3 (2003) 109(2) Acute toxicity of oral exposure on mice: Hom method.weight, this aqueous souion is acually non-poisonous.(3) Accumulation toxicity: accumulation coefficientTable 1 Acute toxicity of aqueous solution of CIO2 with themethod.concentraion of 276. 5 mg/L acted on mice4 Test step of feeding rats for 90days80 rals, each bas the weight of80土10 (g), are dividedSexAmountWay of expsure Dosage(g/kR) Deathin, 4 groups stcasticall, each group has 20 rats, 50% maleoral2.1510and 50% female, among these4 groups, 3 of them are testnogroups and the rest one is contrative. If the total! concentrationmaleof CO2 and CIO2 , CIO; in drinking water is 0.5 mg/L, eachperson drinks2 L/day, weighs 60 kg, then, the total arnount21.5of CIO2, CI02 and CIO; is 1 mg, it crresponds to 1/60 mg/kg weight. Dosage of each group is as folows:4.641oLow dosage group: 0. 5 mg/kg weight( crresponds to 30female10.0times ofof the dosage drunk by person)Moderate dosage group: 1. 0 mg/kg weight ( correspondswo∞times of the dosage drunk by person)Just the same, the acute toxicity results acted on mice ofHigh dosage group: 2. 0 mg/kg weigh (corresponds toNaCIO2 , NaCIO, aqucous solution with the concenuration of 200120 times of the dosage drunk by person)These dosages are poured down throats of rats once permg/L and CIO2 mixed liquid( its concentration ratio is 5:3:2,day continuously for 90 days. Ordinary condition, poisoningconcenlnation of CIO2, cIo; and ao; are 276.5 mg/L, 165.9symptom and death condition of the test animals are observedmg/L and 110.6 ng/L respectively) show that during 14-dayand recorded. Weights of the animals are weighed once perobservation, no mouse is poisoned and died, LDx > 21.5 g/kg .week and amounts of food taken in by the animals areweighl. Therefore, it is known that NaCIO2, NaClO3 aqueousrecorded, uilization eficiency (% ) of food are calculated. Insolution with the concentration of 200 mg/L and the CIO2 mixedthe middle and the end of the test period i. e in the 45th dayliquid with the total concen-ration of 553 mg/L are actuallyand 90th day, blood samples of rats are taken and bloodnon-poisonous aqueous solution.indexes are determined. After 90 days, the blood serum bio-The accumulative toxicity of CIO,chemical indexes such as alinine eransamminase (ALT)， totalNaClO2 , NaClO3 aqueous solutionprotein (TP), albumins ( ALB), globulin (GLB) of rats areThrough acute toxicity tests, aqueous solutions of CIO2 withexarmined and determined. At the same time, weights of liverconcenration of 276. 5 mg/L， NaCIO2 and NaCIO, withand kidney are weighed and liver/body-weight, kidney/ body-concentration of 200 mg/L have the LDy > 21.5 g/kg weight,weight ratios are calculated. Histopathologocal microscopicwhen the dosage is 46. 4 g/kg weight, very few animals appear toexaminations on animal of every dosed group and contrastivebe abnormal. For this reason, dosages are incresed, the LDx ofgroup are done as well.three kinds of aqueous solutions are all tuaken as 46. 4 g/kgweight, to inspect whcther it is accumulated in animals' bodyResults and Discussionater continuously taking in， and thereby ocurring death ofanimals. For each kind of aqueous soution, animals are aranged1 Acute toxicity of aqueous solution ofin dosed groups and contrastive groups, cach group has 20 mice,CIO2, NaCIO, , NaCl0, and the mixed liquid of50% male and 50% female, weighing the body weight andthemchanging the dosage at a 4day interval. Weights of mice are 21士The dosage designed for the acute toxicity study of2. g. The dosage designed for cach stage is as fllows:aqucous solution of CIO2, NaCIO2. NaClO, and the mixedI stage:0. 10 LD。= 4. 64 g/kg weightliquid of them acted on mice follows the Horn's method, theII stage:0.I5 LD。= 6. 96 g/kg weighthighest dosage is21.5 g/kg body-weight. After poisoning, theI stage:0.22 LD = 10. 20 g/kg weightpoisoning symptom and death of mice arc observed. ObservingIV stage: 0.34 LD。=15. 78 g/kg weighttimeis 14 days. Table 1 shows the acute toxicant results ofV stage;0.50 LD = 23. 20 g/kg weightCIO2 aqueous solution with concentration of 276. 5 mg/L actedThe observational period is 20-day. The contrastive groupson mice. It is scen from Table 1 that through the 14-daydrink the tap water. Poisoning way is toally oral exposure.observation, no abnornal reaction and death are found whetherUsing aqueous solution of CIO2 with concenration of 276.the dosage is high or low. According to the designed dosage,5 mg/L, solution of NaCIO2 and NaClO, with cocentration ofresults observed and acute toxicity standard when LDgo is200 mg/L， during the 20-day poisoning tests， dosage isbigger than 10.0 g/kg body-wcight, it is non-poisonous actedincreased progessively, male and female mice are all normal ,on mice， it is judged that CIO2 aqueous solution withgaining weight， no abnormal reaction and death cases.concentration of 276.5 mg/L has the LDso > 21.5 g/kg bodyAccord中国煤化工ferent stage, it isTYHCNMHG110Journal of Donghua University (Eng. Ed. ) Vol.20, No.3 (2003)known that by the end of the 20-day period, accumoulativeweight of ratspoisoning reaches 3. 5 LDx， the accumoulative coffcient ofThe satitical analysis of variance on male and femalethese3 aqucous solutions k is bigger than 5.3, i. e aqueousrats' weight gaining of contrastive group and 3 dosed groupssolution of CIO2 with the concentration of 276.5 mg/L, aqueoushas been done， the probability p > 0.05 ，there isn'tsolutions of NaClO2 and NaClO, with the concentation of 200remarkable difference between contrastive groups and dosedmg/L are non-obvious accumulative ones.groups, that is said that there isn't difference between animals'3 Subchronic toxicity of aqueous solutionweight gaining of the 3 dosed groups and dhat of the contrastiveof CI02 and by- products Cl0; and CIO5group through 90-day feeding.(1) Influence of CIO2 mixed aqueous solution on body-Table 2 Infuence of C1O2 mixed aqueous solution on body-weight of ratsOriginal1st week2nd week3rd week4h weekexGroup°weight( g)weigh(g)weight(g)80.3 +7.3121.8士4.4160.7 +5.6194.6土10.422.0土18.779.2 #5.4.124.3 7.2170.8 t6.7203.9士8.9240.6土14.5Male80.8 +S.1121.3 +4.3166.4 49.9192.3土16.022.2 +23.882.4士6.2122.7 *5.2166.0士6.2207.3土11.4246.3士18.6 .77.0+5.4119.2 +9.3160.2士14.2193.2 +24.8220.4 +17.376.2 +6.8119.5土10.8162.6士10.6183.1 +19.2213.0士30.2Female77.9土3.4113.4 t6.3144.4士14.8175.7 *23.7204.8土23.476.6 +6.9116.5+11.2155.1 +20.4184.4士16.2206.6土18.9Sh week6th week7h week8th week9h weeckSexGroup240.3土19.0250.1土20.8254.7 +25.4256.3 +17.6258.4+17.2270.2 23.2293.5士28.1309.2土16.8317.7 +22.8319.6土24.5255.4 +30. 1268.1 +31.0270.2士20.4273.1 +29.2274.0土18.9275.1 +17.7295.5土17.7308. 6土21.6310.1 +22. 9311.4土19.9241.4 +7.0 .256.8士18.6263.0 +19. 8267.7 +34.8268.4 +23. 3235.7 +25.6240.3 +24.4248.5土24.8250.0 +36.6251.4土28.2233.6土17.8249.7土20.8258.1 +34.4260.0 +22.1261.4士26.5238.8 *34.8247.6土28.4.251.5 +29.0252. 6土20.4255.5 +22. 810th week11h week12th week13th weekweighr(g)260.0 +24.3261.7 +28.8263.1 +17.8263.5 +28.4320.7 +34.6322.0+18.9323.8土12.2323.6土26.6276.4 +20.7278.8 +29.8279.7 +22.2279.9士20.2311.1 +20.8311.8土18.5312.7 +26.4313.0 +26. 2269.8土20.4271.7 +27.8272.3 +34.6273.0 +29.4254.6 x36.6256.0 +26.8257.4 +34.4258.2 +24.6264.4 +28. 8266.3土30.6267.4士34.6268.8 +28.8257.3 +18.8258.6 +24.5258.0 +22.7258.3士19.0*(1) contrnstive group;(2) low dosag group;(3) mnoderate dosage goup;(4) high dosagt group.(2) Influence of CIO2 mixed aquecous soluion on foodstatistical analysis of rats weight gaining (g), daily foodutilization efciency of ratsamount (g) and total food utilization eficiency (% ) showDuring the total test period, diet of animals is normal.that there are not remarkable difference on the rat's weightTable 3 shows the influence of CIO, mixed aqueous solution ongaining, total food amount, and food utilization efficiencyfood uilization eficiency of rats . The results of variancebetween dosed grouDs and contrastive groups(p > 0.05 ).中国煤化工THICNMHGJournal of Donghua University (Eng. Ed.,) Vol.20, No.3 (2003) 111Table3 Infuence of the mixture of CO, on food uilization fficiency of ratsSexGroup*(1)NomberWeight gaining(g)Food cnsumption(g)FU(% )4)10183.2 +17.42548.4 +29.67.19244.4 +22.62597.5 +37.19.42199.1土19.22586. I *227.07.70230.6士20.6.2593.2 +29.68.90.196.0 +24. 62569.3 +37.77.63182.0+18.82608.0+31.46.98Female190.9 *21.32579.2 +28. 8181.7 +25.82646.4 +38.86.87(1) The meaning of1, 2, 3 and 4 is the samt as in Table 2;(2) FUE-food uiliation eficincr.(3) Infuence of CIO2 mixed aqueous solutin on bloodvariance statistical analysis of the total number of WBC and Hbindex of ratscontent among contrastive, low dosage, moderate dosage andOn the 45th and 90th day, all testing animals' blood arehigh dosage group (p > 0.05 ), i. e CIO2 mixed aqueoussolution has no hammful effect on examined bematologic indexhemoglobin( Hb) and cassification etc. are checked, Table 4of rats.is the results of routine blood examination after the 90-dayfeeding. It is seen from Table 4 that there isn't difference onTable 4 Influence of a102 mixed aqucous solution on hematologic index of ratsTotal WBCCassfication of WBC(% )HbGroup"(10%/L)NeutralLymphSingle nucleus(g/L)11. 50土2.4722.80.3153.5 +22.511. 73+3.1023.576.30.2153.5 +25.8Male11. 70士2.0825.376.2145.0+18.712. 88士5.7825. c74.70.150.0 +25.011.59 +2.7323.3150.0土19.311.63 +5.1823.076.50.4142.0+14.512.63 +6.6924.075.7147.0+15.611.84+1.8822.976.9148.5 +21.6"The meaning of1, 2, 3 and4 is the same as in Table 2.(4) Influence of C102 mixed aqueous solution on rats'statistical analysis on the 4 examined blood serum indexes ofbiochemical index of blood serum of ratsmale and female rats of contrastive and high dosage groupsMale and female nats of contrastive group and high dosageshows that there isn't dfference on GPT, TP, WP and GPgroup are slected to examine their biochemical indexes ofcontents in rats' serum betwen contrastive and high dosageblood serum. The indexes to be examined are glutamic-pyruvicgroup( p > 0.05 ).ransaminase( GPT), total protein( TP), white protein( WP)and globe protin(GP), the results are in Table 5. VarianceTable 5 Infuence of CO2 mixed aqucouslution on blood serum indexes of ratsIndcx of detcninationGLT(IU/L)TP(g.L"1)WP(g.L-I)GP(g.L")Mal27.5 +9.5.71.7士4.945.8+3.125.8+3.526.1 +9.670.8 5.044.9 +2.325.9士4.0Fermale23.3 9.871.8 5.445.1 +3.626.7 *2726.8 +9.373.0*5.3 .46.5 +2926.5+5.1' (1contastive group;(4) high dosge group.中国煤化工MHCNMHG112Journal of Donghua University (Eng. Ed.) Vol.20, No.3 (2003)(5) Influence of CIO2 mixed aqueous solution on atssolution of NaCIO2 and NaClO3 with concentration of 200liver/ weight and kidney/ weight of ratsmg/L are all non-obvious accumulational solution.After the 90-day feeding is finished, all testing animals(3) Under the dosages designed in this test, the fllowingare dissected, and their liver, kidney and body-weight areconclusions can be achieved based∞rats 90-day feeding:weighed, the liver/weight, kidney/ weight of each test animal①There is no obvious influence of the mixed liquid onare calculated. Table 6 shows variance analysis of rats ofweight-gaining and food utilization eficiency of rats.contrastive, low dosage, moderate dosage and high dosage②The results of hematological exanination show that thisgroup. The results show that there is no obvious difference onmixed liquid has on influence on WBC and Hb of ratsliver/ weight and kidney/ weight among rats(p > 0.05 ).(p > 0.05).③The results of ALT, TP, ALB and GLO etc.Table 6 Influence of CIO2 mixed aqueous solution onexamination show that in blood serum of rats, there is noliver( kidney)/ weight of ratsobvious difference between male and female of contrastiveex Group" Live/weight(%)Kidney/ weigh( % )group and high dosage group on these4 indexes(p> 0.05 ).(4) The results of variance analysis on rats' liver/ weight2.78 +0.12.0.77 +0.05(%) and kidney/weight (% ) show that there is no obvious3.07士0.100.69+0. 10difference between contrasive group and test group and noMale3.15士0.070.73 +0.06difference among test groups also (p > 0.05 ).2.88士0.350.62 +0.08 .(5) The results of histopathological exanination showthat no pathological change on rats' liver and kidney tssue is2.87 :0.380.81 +0.07found.3.04士0.16.0.76+0.06FemaleTherefore, through the 90-days feeding, CIO2 mixed2.94 +0.230.78 +0.092.98土0.090.83 +0.11liquid ( the total concentration of C1O2, CIO2 and CIO; is 553mg/L, concentration of CIO2, CIO2 and CIO; ac 276. 5,"The meaning of1, 2, 3 and4 is the same as in Table 2.165. 9 and 110. 5 mg/L respectively) has no harmful(6) Histopathological examinationpoisonous action on indexes mentioned above of the test ratsLiver and kidney of all testing animals are examinedunder conditions as this test.histopathoiogically after the 90-day feeding is finished. Nohistopathological change on livers and kidneys of male andReferencesfemale rats of dosed groups and contrastive group is foundthrough microscope examination, that is to say that CIO2[1] 黄君札.环境化学,1987, 8(5): 14-22.mixed aqucous solution has no harmful action on liver and[2] Huang Juni, Wang Li, Ren Namqi et 1. , Waer Research,kidney of rats.[3] Huang Junli, Wang Li, Ren Nanqi at al. . Water Reearch, 1997,31(3): 607 -613.Conclusions[4] Tang T.F. & Gordon G., Enmwir. Sal. & Technol, 1984. 18(2): 212 -215.(1) Research on acote toxicity acted on mice shows,[5] 时文散.二氧化氯处理饮用水工程应用研究.硕士论文.哈CIO2 aqueous solution with concentration of 276. 5 mg/L,尔滨建筑大学图书馆1999,12.aqucous solution of NaCIO2 and NaClO, with concentration[6] BerczJ.P.. et al. , Envir. Heaith Perspectives, 1982 ,45; 472-200 mg/L and CIO2 mixed liquid ( the couceatration ratio is5:3:2, coocentation of CIO2, CIO; and C1O; are 276.5,[7] Couri D. etal. , Envir. Health Perspectives, 1982 ,46: 25 -26.165.0 and 110. 6 mg/L respectively) are non-pisonous王丽,黄君礼.李海波,哈尔滨建筑大学学报,1997 ,30(4):66 -71.aqueous solution.(2) Solution of CIO2 with concentration of 276.5 mg/L,中国煤化工MYHCNMHG