Tackling stunting through improved sanitation

Stunting is the impaired growth and development that children experience from poor nutrition, repeated infection, and inadequate psychosocial stimulation. Children are defined as stunted if their height-for-age is more than two standard deviations below the WHO child growth standards median.

Scientific evidence has shown that stunting in early life especially in the first 1,000 days from conception until the age of 2 has negative, life-long consequences for the child’s physical and mental development. A stunted child is more susceptible to infection. A stunted child is likely to start school with a reduced capacity for learning and processing new information. This translates into lower scores on tests of attention, fluency and working memory.

Concurrent infections associated with stunting increase household expenditure on healthcare. Stunting ultimately impacts national development because of its health and economic consequences. Individuals who are stunted at two years of age are likely to grow up to be stunted adults. Studies have demonstrated that impaired functional development of the brain experienced in early life in association with stunting persists in later life. Stunting has important economic consequences for individuals, households and communities.

Poor nutrition perpetuates the cycle of poverty and malnutrition through three main routes: direct losses of productivity as a result of poor physical health related to malnutrition and disease, indirect losses from poor cognitive development and less time spent at school, and increased healthcare costs for infectious and chronic diseases. Stunted children grow up to earn 20% less in average wages compared to people who are not stunted. The World Bank estimates that a 1% loss in adult height due to childhood stunting is associated with a 1.4% loss in economic productivity.

The main causes of stunting are found within the household and family: poor maternal nutrition and health, inadequate breastfeeding, infection. Unsafe food and water contaminated by environmental pollutants or mycotoxins can lead to infections which hinder growth. Household hygiene practices such as handwashing with soap using clean water and assuring sanitary conditions minimise the risk of infections like diarrhoea which stop children from growing properly. Severe infectious disease can lead to wasting which occurs when a child’s weight is low for their height. This could have longer term consequences on linear growth. It can be estimated that experiencing 5 or more episodes of diarrhoea before age two is the main cause of stunting for 25% of affected children. Repeated exposure to microbes through an unclean environment and poor hygiene can cause subclinical infection and inflammation where symptoms are not visible.

Affected children suffer extensive intestinal damage and are unable to effectively absorb nutrients from their food. The provision of toilets and improvements in water quality are important ways to prevent intestinal diseases and thereby reduce the risk of stunting.

Children born into urban slums are more affected by stunting than national averages. Research from Bangladesh indicates that the prevalence of stunting is significantly higher among children living in urban slums, with about 50% of children under five years being stunted, compared to one-third in non-slum areas . This is consistent with findings from India, where the prevalence of stunting among children under two years in urban slums was 38%, higher than the estimates for children the same age from across the general urban population. Tackling stunting with an intervention focused on slum areas is therefore likely to have a more significant impact.