Ecological study

Ecological studies are special epidemiological studies, which are characterized to put at the level of regions and populations in relationship by attempting to exposure and disease, and not at the level of individuals.

For the investigation of correlations between individual exposures and diseases (eg smoking and cancer ) are the so-called analytical epidemiological studies, such as cohort studies and case -control studies, are available.

However, often exist for many relevant exposure types ( noise, air pollution, chemical pollution of drinking water and food, ionizing / non- ionizing radiation, etc.) no measured values ​​for the individual stress sufficiently large populations. In such cases it is sometimes possible to study disease frequencies and pressure indicators at the regional level (eg county). Such approaches are called ecological studies. In the special problems of such approaches has been mentioned.

The goal of analytical environmental studies is a gradient between clear enough graded exposures and accordingly stepped disease frequencies at the ecological - that is, at the regional - level evidence (ecological dose-response relationship).