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Indian Journal of Community Medicine

Ganga Water Pollution and Occurrence of Enteric Diseases in Varanasi City

Author(s): M. Pandey, V.K. Dixit, G.P. Katiyar, G. Nath, S.M. Sundram, N. Chandra, A.K. Shomvansi, S. Kar, V.K. Upadhay

Vol. 30, No. 4 (2005-10 - 2005-12)


Research question: Whether concentration of Ganga water pollutants is related to occurrence of water borne enteric diseases in Varanasi city. Objectives: 1) To assess if the Ganga Action Plan(GAP), initiated in 1984 to clean Ganga, has been able to restore its water quality to WHO or Indian Standard Institution (ISI) standards. 2) To explore, if concentration of Ganga water pollutants is related to occurrence of enteric diseases in Varanasi city. Study design: Hospital based survey and office records. Participants: OPD patients during July 1998 to June 1999 and indoor patients during January 1996 to June 1999. Setting: Monthly visit to OPD of 5 city hospitals and secondary data from Central Water Commission (CWC), Varanasi. Analysis: Multiple regression, χ2-test, Standardised Euclidean distance. Results: Ganga water quality is still far below even the ISI standards and has a very high relationship with occurrence of said water borne enteric diseases in Varanasi city (R =.797). Survey data on OPD patients raise a suspicion that lack of water treatment practice at home may be major cause of said diseases, in some areas of city. Moreover, sample survey data also indicate that occurrence of enteric diseases is also affected by high population density and concentration of some ethnic and of weaker socio-economic groups. Key words: Water borne enteric diseases, Entero-pathogens.


An unbalanced lopsided resource utilization on earth for fast growing urbanisation, industrialization and armament race (including nuclear and chemical ones) has led to global degradation of the environment. Same is the present situation of the air and water quality in our country. Central Water Commission (CWC) under Government of India, therefore, started monitoring the water quality aspects of Indian river system.

The holy Ganges flowing in the most populated northern India is also now declared unfit even for bathing. The city of Varanasi, of ascetic and tourist importance, and a seat of learning from ancient times, situated on the bank of Ganga draws about 50% of water for domestic consumption of city inhabitants from this river.

After realizing that huge amount of industrial and domestic discharges are being flown into the rivers, it was considered necessary in 1978 to study various quality aspects including pollution parameters in the river Ganga and its tributaries. In 1984 the GAP for cleaning Ganga, was formulated and commenced. By March 1990 Water Quality Monitoring (WQM) Network covered with the help of State Pollution Control Boards (SPCB), 103 rivers and its tributaries. Hence it is quite likely that quality of water will influence the health of surrounding inhabitants.

We therefore started this study with the following objectives:

  1. to explore, if concentration of Ganga water pollutants is related to occurrence of enteric diseases in Varanasi city,
  2. to assess if the Ganga Action Plan(GAP), initiated in 1984 to clean Ganga, has been able to restore its water quality to WHO or Indian Standard Institution (ISI) standards,
  3. to assess trend of the monthly and seasonal mean concentration of 11 Ganga water pollutants parameters from January 1980 to June 1999,
  4. to obtain Standardised Euclidean distances of monthly means from WHO and ISI Standards,
  5. to check if seasonal means of concentration of various parameters in 1980-81, 1992-93 and 1997-98 are equal ot WHO and ISI Standard.

Materials and Methods

For last four points secondary data from CWC, Varanasi office has been collected. For the first, a hospital based study of indoor patients of five water borne enteric diseases has been conducted for a period of January 1996-June 1999 from the Admission /Discharge (A/D) registers of the General Medicine/ Gastroenterology and Pediatric wards of five hospitals. Multiple linear regression and Forward Stepwise regression analysis has been applied to quantify the degree of relationship of water pollutants concentration with occurrence of said enteric diseases. One year (July, 1998-June, 1999) sample survey of OPD patients of enteric diseases from the same hospitals was also conducted and c2 -test of significance is used to find out if type of source of water, food habits, personal hygiene and sanitary conditions are associated with occurrence of enteric diseases. A maximum of 10 OPD patients from General Medicine, Gastroentrology & Pediatrics wards were taken.

The considered 11 Ganga water quality parameters are:

  1. 3 biological -BOD, Total and Faecal coliforms
  2. 2 physical - Temperature and Conductivity (l)
  3. 1 Physico-chemical -pH and
  4. 5 chemical- DO, Sodium (Na+), Chloride (Cl-),Fluoride(FI-), and Nitrate (NO3--).

The following five enteric diseases: (i) Diarrhoea (ii) Dysentery (iii) Viral Hepatitis (iv) Typhoid, and (v) Gastro-enteritis; have been considered and number of indoor patients of these diseases in the five hospitals during January 1996 to June 1999 are the base of this study.

Data Collection:

(i) Data on Ganga water quality

Ganga water quality data on the above mentioned 11 parameters were procured from CWC office at Varanasi with permission of Central and State Govt. Ministries. Levels of concentration have been taken from Assi Ghat just where Ganga touches city area. Hence it is Ganga U/S data in relation to Varanasi city and is about 1 Km. up from the site of Ganga water pumping station of the W/W Varanasi. The concentration levels of the water quality parameters were determined by CWC after analysing the water samples at their Regional Lab. in their office building in Varanasi. The samples for these tests are regularly collected thrice a month at about 10 meters from the left bank of Ganga from about 1/4th depth at the sampling sites.

Monthly data on concentration levels of pollutants are available in CWC, Varanasi for (a) 8 parameters -BOD, pH, Temperature, λ, Na+, CI-, Fl-, Nitrate from January 1980 to June 1999, (b) DO from August 1988 to June 1999, and (c) Total and Faecal Coliform from March 1995 to June 1999.

(ii) Data on occurence of water borne enteric changes

We selected 5 well-known hospitals out of total 53 hospitals, medical centers and PHC in the Municipal limits. Of these the fifth, attached to IMS is only renowned one in the Eastern UP & Bihar. Third one is the district hospital and first two are Charitable Trust hospitals. It is hoped that these are catering the health services to main part of the Varanasi city dwellers.

The diagnosis of all the OPD patients could not be confirmed on the survey day. So the data on only 343 OPD patients with confirmed diagnosis has been used in this paper.

Methods of Analysis

The monthly mean (MM) and seasonal mean (SM) concentrations of the said 8 parameters have been computed for a period of January 1980 to June 1999 to have an idea of trend of level of water pollutants. Conductivity(λ) determinations are useful because they provide an estimate of dissolved ionic matter in the water. High value of conductivity indicates possible pollution sites. Low value of conductivity indicates good quality of water. Seasonal means of DO and BOD for August 1988 to June 1999 and of Total and Faecal coliforms for March 1995 to June 1999 have been computed.

To have an idea how far the Ganga water pollutants have been brought to WHO and ISI standards, the distances of MM from these standards have been obtained by computing the standardised Euclidean distances (SED) of 8 parameters (listed in (A) (i) (a)) during January 1980 to December 1998, of 9 parameters (listed in (A)(i)(b) during August 1998 to December 1998 and of all the 11 parameters during March 1995 to December 1998. For n water pollutant parameters SED is defined as:

, .............. (1)

where XMi = monthly mean concentration of ith parameter
Si =WHO/ISI standard concentration of ith parameter
δi2 = Variance of monthly mean concentration of ith parameter. i=1, 2 ....,n and n = number of parameters, (=8 or 9 or 11)

Student's t-test have been applied to test if SM concentration matches with the WHO and ISI standards of the corresponding pollutant concentrations.

Municipal ward wise distribution of indoor patients of water borne enteric diseases has been obtained from the said 5 hospitals for each month during January 1996 to June 1999.

Year wise distribution of these patients has also been obtained for the same period.

Average number of OPD patients in a month going to various hospitals has been obtained ward wise, to show how various hospitals cater the needs of various parts of Varanasi city.

9 variables of the survey questionnaire are categorised so as to have sufficient number of OPD patients in various categories. To test that some of these variables like Source of drinking water, Distance of their house from river Ganga, Food habit, Type of latrine, Treatment of water at home, Personal hygiene etc. are associated with occurrence of enteric diseases, χ2 -tests of independence of 13 pairs of said 9 variables have been applied.

Next, to explore if occurrence of enteric diseases is related to concentration of the Ganga water pollutants, Multiple linear regression analysis is applied as follows:

For the operational feasibility of collection of observations, the incidence rate of the said enteric diseases could not be determined in its standard form. We, therefore first define the monthly occurrence (Im) of the said diseases for this study on Varanasi city as:

Im = (Nui /Dei) x 100, .............. (2)

where, Nui = Total number of indoor patients of all the 5 hospitals (of any age or sex) residing in Varanasi city who newly contacted one or more of the said diseases (noted from hospital A/D registers) in ith month.

Dei = Total number of indoor patients of all the 5 hospitals residing in Varanasi city admitted for general medical treatment including those in Paediatrics, in ith month.

i = Jan. '96, Feb. '96....June '99.

Thus we quantify the occurrence of water borne enteric diseases in Varanasi city and use it as the dependent variable Y, in multiple regression analysis. The monthly mean concentration levels of the above mentioned 11 water pollutant parameters have been used as the independent variables Xj, j = 1,2,....., 11; to obtain the multiple linear regression equation:

Y = β0 + β1 X1 + β2 X2 + ....... + ........(3) β11 X11

Multiple correlation has also been obtained as a measure of the effect of Ganga water pollution on occurrence of said enteric diseases in Varanasi city. MS-EXCEL software package has been used for this analysis. Forward Stepwise Regression analysis of CSS software package has been applied subsequently. Through it, we can identify the parameters, which are affecting the occurrence of enteric diseases intensely.

Results and Discussion:

Status of Ganga water quality

Trend of concentration levels of the 12 and 5 Ganga water pollutants in Varanasi U/S has been determined1,2,3 using 5 point moving average, regression analysis and multiple regression analysis. Though the trend showed improvement, but on the whole, levels are above standard and hence Ganga water quality is still degraded.

Due to low and medium run offs in rivers Ganga and Yamuna and very dense concentration of large scale urban and industrial centres at Kanpur and Delhi, respectively, the water quality status has gone below standard for bathing and domestic purpose4,5.

Table I: t-test of Equality of Seasonal Means with Standards of Pollutants Concentrations

Year Seasons BOD PH Cond Na Cl Fl No3
1980-81 w **   ** ** ** **  
**     ** ** **  
1981 S ** * ** ** ** **  
** *   ** ** **  
1981 R ** * ** ** ** **  
** *   ** ** **  
1985-86 W **   ** ** ** ** **
**   ** ** ** ** **
1986 S **   ** ** ** ** **
**   ** ** ** ** **
1986 R **   ** ** ** ** **
**   ** ** ** ** **
1992-93 W ** **   ** ** ** **
** ** ** ** ** ** **
1993 S ** **   ** ** ** **
** ** ** ** ** ** **
1993 R ** ** ** ** ** ** **
** ** ** ** ** ** **
1997-98 W **   ** ** ** ** **
**   ** ** ** ** **
1998 S **   ** ** ** ** **
**   ** ** ** ** **
1998 R **   ** ** ** ** **
**   ** ** ** ** **

Case-II: 1988-1998

Year Season DO
1988 R *
1988-89 W **
1989 S **
1992-93 W *
1993 R *
1993 S **
1998 R **
1998 W *
1998 W **

Case-III : 1995-1998

Year Season DO Parameters
Total Coliform Fecal Coliform
1995 S    
1995 R    
1995 W    
1998 S * *
* *
1998 R * *
* *
1998 W * *
* *
NOTE: * indicate 5% significant difference and **indicates 1% significant difference

After about 17 years of GAP implementation, some researchers have declared that Ganga water in Varanasi also is not fit even for human bathing. Presence of enteropathogenic bacteria has been demonstrated6,7 in their studies on river Ganga water quality at Varanasi city and at Pratapgarh, respectively.

In our study, the Seasonal Mean Concentrations of DO & BOD and Total & Faecal coliforms are found to be much higher than the respective tolerance limits as given by the WHO and ISI standards. The SED of monthly means of 8, 9 and all the 11 parameters, respectively, from WHO and ISI standards have also been obtained. It seems that the said distances from both the standards are very high and this is also supported by the results of Student's t-tests, given in Table-I for seven parameters SM for 1980-1998, for DO during 1988- 1998 and also for Total anf Faecal Coliform during 1995-1998. However the coliform concentrations are not significantly high till 1995 and have become significant during 1998.

It seems that due to continuously exploding city population, the insufficient capacity of the sewage treatment plants which started functioning in 1993, led to rise in coliform concentrations to a significant level after 1995 even though the DO and BOD levels are satisfying both the standards. The self purifying property of holy river Ganga also helped to maintain coliform concentrations non-significant up to 1995 but could not do so after 1995. It is, therefore, worth investigating if river Ganga water pollution level has any relation with occurrence of water borne enteric diseases in this city.

Distribution of patients

It is found that Kotwali has highest occurrence of water borne enteric diseases followed by Chetganj, Chowk and Adampura. The occurrence in Kotwali exceeds that in these other 3 Municipal wards by about more than one and half to two times. Except Chetganj the other three wards are on the bank of river Ganga. One may therefore, suspect that nearness to river may be inducing enteric diseases.

It is also worth noting that each of the above-mentioned 4 Municipal wards has one hospital selected for study. Existence of nearby hospital might lead to more reporting from nearby patients. From other distant parts of the city the occurrences may not be reported in the considered hospitals. Another point to be considered is the population of respective wards so that instead of absolute number of occurrence the occurrence ratio with population of ward may give a different picture, as the Kotwali (with highest occurrence) and Chowk (with the 3rd highest occurrence) are parts of old Varanasi and most densely populated. It is found that SSPG hospital, being the main District hospital controlled and funded by State Govt., is approached by residents of almost all parts of the city.

Variables associated or related with occurrence of enteric diseases

Table II gives the variables from data collected from survey of OPD patients of 5 hospitals chosen for c2 -test of independence, and Table III the results of these tests, respectively. Diseases in this table include Typhiod, Jaundice/ hepatitis and all other enteric diseases, e.g. Diarrhoea, Dysentery, Colitis, Vomiting, Cholera etc.

χ2-test also includes Municipal wards and hospitals as variable categories. It is interesting to see that disease and Municipal wards are significantly associated, and disease is highly significantly associated with hospitals. Further, Municipal wards are highly significantly associated with type of latrine. Since the four Municipal wards with high occurrence of disease, each has a hospital, it appears that disease is indirectly associated with type of latrine at least in some Municipal wards though not shown when all the wards are combined in 7th test (of Table III). Moreover, disease is found to be significantly associated with the practice of water treatment at home.

Hence it appears that there are some areas of Varanasi where occurrence of disease is due to unhygienic sanitary conditions and intake of contaminated water, possibly.

Multiple linear regression and Forward Step-wise regression analyses

Most of the important cities are situated on the banks of rivers and those river water is generally used for consumption of inhabitants. Presence of harmful chemical pollutants and toxic trace elements in natural water in U.P. has been found and its effect on human beings also has been studied8. Relationship between entero-pathogenic microbes in river or other water systems and occurrence of water borne disease outbreaks has also established9,10.

Table-II: Variables from survey Data and their Categories for Chi-square test

Variables Categories
1 2 3
1. Disease Typhoid Jaundice/Hepatitis Rest
2. Food habits Always fresh Fresh and stable Almost always stable
3. Treatment of water at user end No treatment Using Water Filter Aquaguard, chlorine tab. Boiling etc.  
4. Personal Hygeine Always using Soap Sometimes using soap, or soil or ash,
using water only
5. Distance(Km) from Ganga D≤ 1 1 < D< 4 D ≥ 4
6. Income of H.H. < Rs. 2000 > Rs. 2000  
7. Profession Service Business Professional
and others
8. Source of water (drinking*, cleaning) Supply water Hand pump Tubewell & others
9. Type of Latrine Sewer line Septic Tank All others

Table-III: Chi-square tests of independence from survey data

Variables tested d.f. Chi-square Calculated
Disease vs water (Drinking + Cleaning) 2x2 3.98
Disease vs Cleaning water 2x2 1.56
Disease vs Drinking water 2x2 2.61
Disease vs Wards 2x1 6.94*
Disease vs Type of Latrine 2x2 40.58**
Disease vs Hospital 2x3 22.02**
Disease vs Latrine Type 2x1 2.11
Disease vs Food Habit 2x2 2.82
Disease vs Treatment of Water 2x1 6.2*
Disease vs Personal Hygiene 2x1 0.85
Disease vs Income 2x1 2.43
Disease vs Profession 2x2 2.04
Disease vs Distance from Ganga 2x2 2.09
* P< 0.05 and ** P < 0.01

Though it is claimed11 that, a relationship between some level of coliform contamination in water system and probability of water borne diseases outbreaks has never been demonstrated, several other studies12-17 tried to establish relationship between occurrence of diarrhoea and infantile diarrhoea and type of source of water, indices of personal and domestic hygienic behaviour and cleanliness.

Since treatment of water at home seems to be associated to diseases the results of ANOVA of multiple regression analysis were obtained. It was seen that the occurrence of enteric disease is highly significantly related to the concentration levels of Ganga water pollutants. Multiple correlation is very high (R=0.797) and R2 =0.636 indicates that about 64% variation in occurrence is explained by these 11 parameters.

In other words, the Ganga water pollution has very significant effect on occurrence of enteric diseases in Varanasi city (P < .00032).

The concentration of Nitrate, Chloride, Conductivity and Faecal coliforms in the Ganga water have highly significant effect (P=.00031,.004, .006 and .03, respectively). The Forward Stepwise Regression analysis results indicates that only 4 parameters viz, Nitrate, Chloride, Conductivity and Faecal coliforms are sufficient to explain almost all the variation (63.4%) since all the 11 parameters can explain only little more (=63.6%).

Since the raw Ganga water is treated by Varanasi Water Works before distribution, so one expects that Ganga water pollution level cannot have any relation with occurrence of enteric diseases in the city. But the data on Ganga water pollutants concentrations and occurrence of said diseases are found to be related. Occurrence of enteric diseases is highly significantly (P< .01) related with Nitrate, Chloride & Conductivity and less significantly (P< .05) with Faecal coliform. Hence it is quite likely that the drinking water used by city dwellers may be causing the enteric diseases. Since even if the treatment at the water works is properly done, contamination may take place due to seeping old supply pipelines, or use of raw Ganga water by some, due to bathing and drinking at the times of religious festivals.

The results of the present study indicate that a deep exploration should be done to check if the water consumed by city inhabitants is contaminated with entero-pathogens, or there are other factors, such as improper personal hygienic practices, wrong food habits and dirty surroundings in and out of their residence, responsible for enteric infections in this city.


The permission granted by the CWC, New Delhi, for using their data on Ganga water quality at Varanasi site is sincerely acknowledged. The Co-operation and continuous help by the Chief Engineer, CWC, Lucknow, and the Superintending Engineer, CWC Varanasi has been immense. The unreserved disseminatioin of data with clear explanation of any queries by all the staff at CWC, Varanasi is very much appreciated.

The Access to the Medical Records and Registers of indoor patients granted by the CMO's the MS's of all the five hospitals and the Director, IMS, BHU, without which this study could not be done; is very thankfully acknowledged. We are thankful to all the doctors (too many to name) of the selected five hospitals of Paediatrics, General Medicine and Gastro OPD for long hours they devoted in helping us identify the cases to be included.

The patient, cheerful and untiring co-operation received from the Incharges of Medical Record sections, the Staff Nurses in the indoor Paediatrics and General Medicine wards of SSL and SSPG Hospitals are gratefully acknowledged. Last but not the least, the efforts put into collect all the data by the field investigators is also appreciated.


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Banaras Hindu University, Varanasi
E-mail: [email protected]

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