Types of Studies - L1
Scientists evaluate all relevant evidence when deciding about potential health hazards, including epidemiology, animal, and cellular studies.
A mix of studies in different research areas is essential for the evaluation of potential adverse health effects of human exposure to an agent. Different types of studies investigate distinct aspects of the problem.
Laboratory studies on cells aim to elucidate the fundamental underlying mechanisms that link exposures to biological effects. They try to identify mechanisms based on molecular or cellular changes that are brought about. The key limitation in these studies is that single cells or tissues are removed from their normal living environment which may affect their response to the exposure.
Another type of study, involving animals, is more closely related to real life situations. These studies provide evidence that is more directly relevant to establishing safe exposure levels in humans and often employ several different field levels to investigate dose-response relationships.
Epidemiological studies or human health studies are another direct source of information on long-term effects of exposure. These studies investigate the cause and distribution of diseases in real life situations, in communities and occupational groups. Researchers try to establish if there is a statistical association between exposure and the incidence of a specific disease or adverse health effect. However, epidemiological studies are costly and they involve measurements on very complex human populations and are difficult to control.