While descriptive health studies can first alert scientists and community members that an exposure may be a health hazard, analytical health studies can provide further evidence of an association between exposure and disease. Analytical health studies in environmental epidemiology involve comparing disease rates in a group of people with exposure to a contaminant with disease rates in a group of people without exposure. Below are some of the different types of analytical health studies that can be conducted in a community.

	ANALYTICAL HEALTH STUDIES
type of study Cross-Sectional Study (study of health and exposure at one point in time) questions that may be answered at this specific point in time, does it appear that this exposure is related to this health outcome? does the data suggest that this exposure may be a risk factor for developing the health outcome? target population defined population that you are interested in at a specific point in time information and resources needed method to measure the exposure record of disease occurrence environmental scientist to measure the exposure statistician or epidemiologist to analyze data limitations cannot determine if the exposure occurred before or after the disease developed in a person type of study Cohort Study (study of people with and without exposure over a period of time) questions that may be answered are people with this exposure more likely to develop this health outcome? is this exposure associated with this health outcome? is there evidence of cause and effect relationship between exposure and health outcome? target population people who were exposed to the contaminant people who were not exposed to the contaminant information and resources needed method to measure exposure record of disease occurrence environmental scientist to measure exposure statistician or epidemiologist to analyze data limitations may be difficult to correctly determine if a person develops this health outcome or not is often expensive to do and can take several years to conduct may be difficult to get sufficient study power type of study Case-Control Study (study of people with and without a disease over a period of time) questions that may be answered are people with this health outcome more likely to have been exposed? is this exposure associated with this health outcome? is there evidence of cause and effect relationship between exposure and health outcome? target population people who have the health outcome people who do not have the health outcome information and resources needed method to measure exposure record of disease occurrence environmental scientist to measure exposure statistician or epidemiologist to analyze data limitations may be difficult to correctly determine if a person was exposed to a contaminant or not is often expensive to do and can take several years to conduct may be difficult to get sufficient study power

An important limitation of this type of study is that it cannot determine what came first: the exposure or the health outcome. Therefore, this type of study can only suggest that there might be a possible connection between a hazard and a health outcome. A cohort study or case-control study can give you stronger evidence of this connection.