the last cause refers to the environmental conditions. they play a crucial role in influencing the nutritional status via the health situation and mainly include the availability of safe water, sanitation, and environmental safety, and shelter. water and sanitation improvements, in association with changes in hygiene behaviour, can have significant effects on a population and its health by reducing a variety of conditions for diseases such as diarrhoea, intestinal helminthes, guinea worm, and skin diseases. these improvements in health can, in turn, lead to reduced morbidity and mortality and improved nutritional status.