Research published today shows that schools providing clean water report fewer children off sick. It is the first study to investigate whether providing drinking water in schools can reduce absenteeism.

Researchers looked at absentee rates in eight schools in Cambodia - half of which received treated drinking water, and half of which did not. The 26-week study period spanned two terms - one in the country's dry season and one in the wet season. The absentee records of 3520 children were taken into account.

They found that during the dry period, children without access to clean water were about 2.5 times more likely to be absent from school than children where water was provided.

Prof Paul Hunter from UEA's Norwich Medical School said: "We focused our intervention on local communities that have poor access to clean drinking water. Each participating school was given a 20-litre bottle of clean drinking water per class each day.

"We found lower absenteeism in the schools that received the free clean water - however this association was only seen in the dry season. During the wet season, absenteeism increased in all eight schools, which is explained by children being kept off school to help in the fields.

"Education is one of the most important factors that enables children to fulfill their potential later in life and reduce poverty. Better education is also associated with substantial health gains - especially for child health in future generations and in reducing child mortality. However, even when schooling is available, absenteeism rates can be high. Clearly reducing student absenteeism is vital to improve educational attainment and alleviate poverty.

"As well as helping to reduce waterborne infectious disease, providing free drinking water helps combat dehydration. Even mild dehydration in children may be associated with poor health, and previous studies have shown that keeping well-hydrated improves cognition and energy levels in children. So providing free water in schools would improve children's general wellbeing and learning experience.

"The overall cost of the scheme equated to $1.4 USD per child per year - a very modest cost compared to the potential educational benefits and subsequent life potential," he added.