groundwater quality and human health: sunderrajan krishnan, carewater
TRANSCRIPT
Groundwater quality and Human health
Sunderrajan KrishnanCAREWATER
INREM Foundation,Anand, Gujarat
ContentsIntroduction
Main groundwater-health problems in IndiaBiologicalFluorideSalinityNitrateArsenicIronEmerging problems
Experiences in Fluorosis mitigation and learnings
Some debates on RO
Some thoughts on policy issues
Introduction
• Water borne diseases are a massive burden on society
• The impact of water borne diseases is higher on the poor who have poorer nutrition
• Incidences of some water borne diseases are decreasing, whereas others are increasing
• Most of these diseases are preventable by consumption of safe drinking water
Drinking
Other uses
Cooking
Groundwater
Tank/Pond
Piped watersupply
Sources Domestic Uses
Local picture of drinking water access and variable water quality
Drinking
Groundwater
Pond
Piped watersupply
Sources
avai
labi
lity
coli
form
salin
ity
fluor
ide
avai
labi
lity
coli
form
avai
labi
lity
time
coli
form
Human, Animal waste
Fertilizers, Pesticides
Groundwater flowTDS TDS
TDS
Fl
Fl
Transport processes within the aquifer
Different contamination problems
Biological contamination
• Child mortality in India is 57/1000
• 9.1% of 0-5 yr mortality due to Diarrhoel diseases
• Overall DALY from Diarrhoel > 22 million years
• Poor sanitation and flood conditions are the main causes
• Several low cost filters are being developed now; yet propensity to spend among poor not so high
Nitrate contamination
• Standards are for 45 mg/l
• Studies support Methaemoglobinemia in infants
• Suspicions for being carcinogenic, respiratory problems, Diabetes
• Low cost solutions for Nitrate removal do not exist
Salinity
• Ingress and inherent salinity in many parts of India
• But what are the health symptoms from salinity?
• Can kidney stones be attributed to salinity? Though lack of proper hydration is linked to Kidney stones, hardness by itself is not
• Though there is high incidence of Kidney stone in coastal areas
Total costs due to Kidney stones
In salinity affected villages,
• Medical costs = Rs. 5790 per person per year
• Wage loss costs = Rs. 2690 per person per year
• Drinking water costs = Rs. 750 per household per year
Social costs due to Kidney stones form a significant part of income
Source: ICAR Studies
Arsenic
• Arsenic in eastern parts of country
• Arsenicosis exposure to 16 million people (7 million > 50 ppb exposure)
• New areas in Nepal Terai, Assam, Bihar
• Linked closely to occurrence of Iron
Source: Jadavpur university
Iron• Safe limit of 1 mg/l
• No health based guideline suggested by WHO
• People report of gastro-enteritic problems, but not supported by medical studies
• Iron overload, Hereditary Haemochromatosis, Liver Cirrhosis
• Taste, odour, skin, hair, pipes, cooking
• People resort to unsafe water due to taste of Iron
• Link with Arsenic
Fluoride contamination
• Hydro-Fluorosis causes by consumption of high Fluoride in water
• Not just Dental and Skeletal Fluorosis, but variety of problems with brain, liver, kidney, heart diseases
• Estimates vary from 10 to 65 million people exposed
• DALY of 38.5 per 1000 population (NEERI, 2007)
Source: CGWB
Fluorosis
Water
Food(black tea, rock salt) Occupation
(Mines, glass etching)
Nutrition(Ca, Mg,Vitamins)
Crops Metabolism
Society
Social, economic, cultural impacts(effect of medicines, wage loss, psychological setback)
Fluorosis mitigation programmes
• More than 50% of Fluoride intake can be through food grown locally
• Fluorosis is linked much with climatic and nutritive factors
• Teaching of Fluorosis is not present in current Indian medicine or engineering literature
• Fluorosis patients can incur high costs (wage + medicine losses)
16 %21 %6 %26 %cost/annualincome
2.31.71.31.1afflicted no/household
Rs. 12857 Rs. 8719 Rs. 19741 Rs. 4593 per capita annual
wage loss
Rs. 1724 Rs. 2807 Rs. 1489Rs. 861 per capita
annualmedical cost
North Karnataka
(in 2005)
Kolar(in 2005)
Dausa(in 2005)
North Gujarat
(in 2002)
Medical and Wage loss costs
Fluorosis mitigation programmes …. Cont’d
• Most Fluorosis mitigation programmes have been water supply programmes
• Mitigation and reversal of symptoms is very slow, so patients lose much hope after few years and resign to fate
Fluorosis mitigation programmes …. Cont’d
• Started mainly as De-fluoridation programmes
• Nalgonda filter (using Alum) in 1970s … NEERI
• Activated Alumina (AA) as an advancement
• Reverse Osmosis (RO) with proper membrane can remove Fluoride ions
• New materials, … Resin, Chitin, Bio-polymer adsorbent, etc.
Fluorosis mitigation programmes …. Cont’d
• Water treatment: AA and RO
• Roof top rain water harvesting
• Pipe water supply
• Recharge
Fluorosis mitigation programmes …. Cont’d
• Main options today are AA and RO
• AAMinimum of 1mg/g adsorption. Requires regeneration every 4-5 monthsNew materials with 8-9 mg/g adsorptionAl-Fl complexes a health concernHas wide industry application, so is low-cost and availableAA filters not available in marketNo electricity required
Two main programs for AA are SWACH and Mytry
Fluorosis mitigation programmes …. Cont’d
• SWACH and Mytry
UNICEF and IITK tested the AA DDU filters and implemented in 2 locations
Awareness programmes, village regeneration centres
Mytry later transitioned into filter manufacturing company
Currently some maintenance of filters happens in Rajasthan, but not widespread
Fluorosis mitigation programmes …. Cont’d
Health based mitigation measures
Studies say upto 80% bio-available Fluoride enters through food (Reddy R, 2008, AP) and 60% through food (Chakma, 2007, MP).
Safe water can prevent Fluorosis, but can it mitigate?
Calcium, Magnesium, Absorbic acid (Vitamin C) are suggested till now
Successes have been achieved for few patients by Dr. AK Susheela, Dr. T. Chakma, Dr. Sunil Gupta and Dr. Raja Reddy
But can these be achieved on a larger scale? Nutrition supplements through Atta, … other food items ?
Fluorosis mitigation programmes …. Cont’d
Fluorosis mitigation: water and health perspectives
• Understanding of Fluoride mobility and distribution• Fluorosis needs to be in medical and public health
curriculum• Doctors should push patients towards need for safe
water• Mitigation needs to be tried in mass trials and
standardized• Options for safe water needs to be available: rain water
storage, low cost treatment and services etc.
Debates with RO• Cost/litre• Effluent disposal• Does it really treat for required contaminants?• Maintenance• Is it safe for health?• Is it really required?
Successfully operating RO plants in south Gujarat
100%42%10%Reach
3258630Buyers in village
2500 litres1200 litres300 litresProd/dayRe 0.6Re 0.280Cost/litre5 lakhs2.32 lakhs1.25 lakhsPlant cost
6000 litres2000 litres200 litresStorage1000 lph560 lph250 lphCapacity
Maximum-AverageMinimum
Suppliers of plant are varied (ISO, non-ISO)
Reach within village shows wide variation,
Off-shoot water suppliers cover surrounding villages,
Non-users have very poor drinking water facilities
Variability in size, cost/litre, % of reach and production
Treatment aspects of RO water
• RO treats only according to the specific membrane capacity
• Pre and post treatment is required
• Although pure distilled water can be harmful for health, NRC, 1983 reports no health based guideline for RO water
• Effluent for RO should be disposed properly, but currently no official safety standards exist in India
Monitoring of water quality
• Network of govt agencies insufficient
• NRDWQM program is in progress
• Several tier of monitoring eg. Assam where field kits are employed along with 5 PHED labs and IIT G over seeing quality control
• New low cost digital instrumentation are being developed eg. in IIT B
Issues with policy
• Who is responsible for groundwater quality and health problems?
• Do we have enough understanding of mobilization processes of contaminants?
Health department’s role
• A framework on water quality should come from a concept of overall health
• All water quality problems of a place need to be addressed eg. Assam (Iron + Fluoride + Arsenic filter)
• Health agencies need to accept their responsibility
In summary• Better physical distribution needs to be known
• Bringing people to be concerned on water quality and health is not an easy task
• New treatment solutions coming up; but comprehensive local solutions to water treatment needs to be developed
• Doctors can play a key role in disseminating water quality information