The LaLonde report suggests that there are four general
determinants of health including human biology, environment, lifestyle, and healthcare services. Thus, health is maintained and improved not only through the advancement and application of health science, but also through the efforts and intelligent lifestyle choices of the individual and society. The Alameda county study examines the relationship between lifestyle and health. It has found that people can improve their health via exercise,enough sleep, maintaining a healthy weight, limiting alcohol use, and avoiding smoking A major environmental factor affecting health is water quality, especially for health of infants and children in developing countries.