Yamuna river case study 2014

1. Quantitative Microbial Risk Assessment
Case Study-Yamuna River
In the International Perspectives on QuantitativeMicrobial Risk Assessment-III
At IIPH Hyderabad India
Friday, 27.03.2015
Team Members:
Neethu Puthumadathil
Hima Wani
Nikita Chadha
Dr. Vanisree
Shailender Kumar

2. Introduction
• River Yamuna, with a total length of around
1370 km is the largest tributary of the Ganges.
• Its source is at Yamunotri in the Uttarakhand
Himalaya regions.
• It used to be a clear blue river but since the past
few decades it has turned into one of the most
polluted river in the world, especially Delhi,
which dumps about 57% of its waste into the
river (Central Pollution Control Board, 2005)

3. Representation of the SCenario

4. Problem Statement:
To estimate bacterial risks of infection annually for villagers of village “DD” using
all possible combinations of given activities in a year.
Objectives :
•Assessment of risk with respect to “de minimus” or more substantial
• Groups of people at most risk and activities associated.
• Rank exposure in decreasing order of their annual risks of infection and risk
management approaches for minimizing these exposure risks.
• To assess reduction in fecal coliforms in order to meet the USEPA allowable
annual risks of microbial infection guideline for recreational water contact.
• To check uncertainties in analysis.

5. Hazard
• Identified biological hazard Shigella spp. and Vibrio. Spp.
• Characteristics
• Gram-negative bacteria with a curved-rod shape
(comma shape)
• It is anaerobic type of microorganism found
in saltwater, and do not form spores.
• Cause acute diarrhoeal disease
Vibrio Spp.
• Gram-negative, facultative anaerobic, nonspore-
forming, nonmotile, rod-shaped bacteria.
• cause serious intestinal diseases, including
bacillary dysentery
Shigella spp.
Source: Guidelines for Drinking Water, WHO (2011)

6. EXPOSURE PARAMETER
Source
Route of
exposure
Exposure
media
Frequency of
exposure
Duration
Exposed
Populations
Scene 1
Stream
AA
Fecal – Oral
Route
Drinking water 365 days
Adults,
Children,
Pregnant
women
Scene 2
Stream
AA
Fecal – Oral
Route
Drinking water
32 times
(4 months)
45 mins
(for 1 event)
Adults and
Children

7. DOSE RESPONSE
FC in stream
AA
Pathogen to FC
ratio
Number of
Pathogens Concentration
Ingestion(per
event)
MPN/100 ml MPN/100 ml MPN/100 ml MPN/ml
1.50E+07
Shigella
Children 5.49E-07 8.24E+00 0.08235 37
Shigella adult 0.08235 16
Vibrio children 3.29E-06 4.93E+01 0.49335 37
Vibrio adult 0.49335 16
Dose
Number of days of
exposure α N50 P(daily) infection
P(annually)
infection
3.0469
5 32 2.65E-01 1.48E+03 6.80E-03 0.196247188
1.3176 32 2.65E-01 1.48E+03 2.97E-03 0.090774512
18.253
95 32
2.50E-
01
2.43E+0
2 1.72E-01 0.997611045
7.8936 32
2.50E-
01
2.43E+0
2 9.45E-02 0.958225953
Pant, A. and Mittal, A. K. (2007) Monitoring of pathogenicity of effluents from the UASB based
sewage treatment plant. Environ Monit Assess. 133:43-51.
Exposure Factor Handbook, 2011

8. DOSE RESPONSE (Point Estimation)
Shigella spp. Vibrio spp.
Sub-
Population
Drinking Recreational Activities
Sub-
Population
Drinking
Recreational
Activities
P(d) P(y) P(d) P(y) P(d) P(y) P(d) P(y)
Child 0.065638 1 0.006804 0.196247 Child 0.479342 1 0.171926 0.997611
Pregnant
woman
0.113811 1 NA NA
Pregnant
woman
0.556901 1 NA NA
Adult 0.135943 1 0.002969 0.090775 Adult 0.582022 1 0.094469 0.958226
Probability of infection (daily and annually)

9. Ingestion Parameters for Monte Carlo
Input Parameter Mean STD
Fecal Coliform(FC) –
MPN/100 ml 1.50E+07 8.00E+02
Ingestion Volume –
ml/event 37 26
Example for Recreational Activity in Children

10. Monte Carlo Analysis

11. RISK ESTIMATION
Monte Carlo P annual (Recreational activity) P annual (drinking water)
Children Adult Adult Child Pregnant woman
Shigella Vibrio Shigella Vibrio Shigella Vibrio Shigella Vibrio Shigella Vibrio
mean 0.209848 0.993201 0.106854 0.925442 1 1 0.99985 1 0.999998 1
median 0.195849 0.997588 0.090551 0.95794 1 1 1 1 1 1
5th percentile 0.102447 0.970573 0.036228 0.748462 1 1 0.999965 1 1 1
Confidence interval 0.314854 0.999834 0.189348 0.997169 1 1 1 1 1 1
95th percentile 0.364634 0.99994 0.227941 0.998878 1 1 1 1 1 1
99th percentile 0.468347 0.999992 0.324546 0.999865 1 1 1 1 1 1

12. RISK CHARACTERIZATION
Recreational activity Drinking water
Children Adult Adult Child
Pregnant
woman
Shigella Vibrio Shigella Vibrio Shigella Vibrio Shigella Vibrio Shigella Vibrio
Risk v/s
Concentration
0.04576 0.027921 -0.03347 -0.009 0.009635 - 0.016872 - 0.044285 -
Risk v/s Ingestion 0.993032 0.53566 0.9955520.619868 0.062095 - 0.077462 - 0.070817 -
Correlation of the annual Probability of Risk v/s
Input Parameters

13. RISK COMMUNICATION
• Survey
Percentage of people boiling or filtering the drinking water
Homes with sanitation facility
Need for sanitation and clean drinking water
• Awareness
Radio and TV announcements
Gram Panchayat meetings

14. Drinking Water
Pathogen Population
Maximum allowable
concentration
Reduction required
Shigella Children 1.39E+05 1.08E+02
Adults 5.53E+04 2.71E+02
Pregnant 7.05E+04 2.13E+02
Vibrio Children 3.05E+04 4.92E+02
Adults 1.21E+04 1.24E+03
Pregnant 1.54E+03 9.74E+03
Recreational Activity
Shigella Children 1.78E+07 8.43E-01
Adults 4.11E+07 3.65E-01
Vibrio Children 9.02E+07 1.66E-01
Adults 3.90E+05 3.85E+01
RISKMANAGEMENT

15. RISK MANAGEMENT
• Awareness
• FC is 100 fold higher than the maximal
allowable concentration of FC in Drinking
water
• Need for need for treatment of stream water
AA
• Establishment of treatment plant/primary
solution

16. REFERENCES
• Microbial fact sheets, Chapter 11, Guidelines on quality
of Drinking water, WHO, 2011
• Pant, A. and Mittal, A. K. (2007) Monitoring of
pathogenicity of effluents from the UASB based sewage
treatment plant. Environ Monit Assess. 133:43-51.
• EPA. 2011. EPA Exposure Factors Handbook, available
online
at:http://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid
=236252

17. THANK YOU