To be able to understand the importance of the environment for our health, we need to know a little about the interdependence between environment and humankind. This unit will look at interactions between plants, animals and the physical and chemical environment, as well as considering ways in which humans have altered, and are altering this environment. These changes have health implications that are not always immediately obvious. Frequently, we initiate changes that are going to have their effects some time in the future, and we will be looking at the legacies that we leave to future generations. We move on to consider our own demise, and ask what exactly it is that we think we will be leaving for those who follow. This study unit is just one of many that can be found on LearningSpace, part of OpenLearn, a collection of open educational resources from The Open University. Published in ePub 2.0.1 format, some feature such as audio, video and linked PDF are not supported by all ePub readers.