In Study Session 1, you read about the need for an adequate, safe and accessible water supply. If there is an insufficient quantity of water, or if the water is contaminated, this can have serious effects on people’s health and can be the cause of many different illnesses – even death. This, of course, impacts on the economic well-being of the community. In this study session, you will look more closely at what is meant by safe and unsafe water, and you will learn why water is important for human health. You will consider the various classifications of diseases associated with water and examine the situation in low-income countries in relation to these diseases.