Our environment can have an enormous effect on our health. Air and water pollution have gotten most of the attention. But scientists and public health experts also see major health consequences associated with the "built environment." That's the environment we construct around ourselves -- our homes, churches, roads, and schools. The quality of these places can influence our health and even determine our lifespan. In public health circles, the built environment is considered one of the social determinants of health. These are factors that shape health but may be out of our own personal control. These social factors are also linked to significant health disparities between some racial groups. In the next installment of our series on social determinants of health, Stephanie Hemphill reports on new efforts to build neighborhoods that can actually improve the health of residents.