SODIS – SOLAR WATER
DISINFECTION
IN SRI LANKA
The problem
Fresh water is an increasingly scarce resource, even
more so, access to clean, potable water for people is
very limited. An estimated 1.1 billion people or one
sixth of the world’s entire population lack a safe water
supply through pipes, bore holes, dug wells or protected
springs.
This is a problem that is likely to increase. As the
population grows the available clean water becomes
insufficient.
The lack of access to ‘good quality’ water leads to a
greatly increased risk of contracting water-borne
diseases, commonly diarrhoea, cholera, typhoid fever,
hepatitis A, amoebic and bacillary dysentery. An
alarming 4 billion cases of diarrhoea are reported
annually causing over 2 million deaths. In developing
countries water-borne diseases cause 15% of all child
deaths (under the age of five). Further, frequent attacks
of diarrhoeal diseases can cause children to become
malnourished and more susceptible to other diseases
such as respiratory illness.
In Sri Lanka, despite being a water-rich tropical country,
a large percentage of the population does not enjoy
access to clean drinking water. According to official
figures, only 57% of Sri Lankans can claim to have
Figure 1: Placing plastic bottles
on the roof to expose them to the
sun, Sri Lanka. Photo: Practical
Action / Zul.
clean, safe water within their reach. This leaves nearly half the population having to acquire
their water from ‘unsafe’ means such as streams, rivers, unprotected wells and open water
bodies. Thus, diarrhoea infections, and serious epidemics of cholera, dysentery and typhoid
are common.
In many developing countries, the public health condition can lead to a dramatic spread of
water-borne epidemics. Cholera is endemic in 80 countries and a serious worldwide concern
still, even though the number of deaths from intermittent outbreaks has reduced due to
improved treatment. The onus should be on preventing epidemic outbreaks and then
stemming their spread by adequate treatment measures and hygiene promotion.
Simple, hygiene practices in everyday life can have a huge impact on the public health
condition in developing countries. It has been found that hand washing (with soap, ash or
other cleaning agent) alone can reduce diarrhoeal disease transmission by one third. Hand
washing, combined with safe disposal of human waste (faecal matter) and careful storage and
handling of water can have great benefit towards reducing water-borne infections. Treating
water to improve its quality should be combined with these health-promoting practices to
make a lasting change in the public health of people in developing countries such as Sri
Lanka.
Practical Action, The Schumacher Centre, Bourton on Dunsmore, Rugby, Warwickshire, CV23 9QZ, UK
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