Environmental Health in the Preindustrial World

Human health—and human disease—have always been intimately connected to the environment. The environment contains the positive, in the form of air, water, and nutrients, and the negative, in the form of bacteria, viruses, and toxins. Humans have developed elaborate defense systems to protect against adverse environmental effects. These include immune systems that attack bacteria and other foreign bodies, DNA repair enzymes that defend the integrity of genetic structure, and metabolizing enzymes that degrade ingested compounds and prepare them for excretion. When these systems become overwhelmed or operate inefficiently, disease and death can occur.

The awareness that the environment influences disease dates back at least to the time of Hippocrates. The first proven case of an illness linked to an environmental cause did not occur, however, until 1854 in London when physician John Snow showed that water pollution was responsible...