Environmental Benefits Mapping and Analysis Program (BenMAP)
How Does BenMAP Work?
BenMAP is primarily intended as a tool for estimating the health impacts, and associated economic values, associated with changes in ambient air pollution. It accomplishes this by running health impact functions, which relate a change in the concentration of a pollutant with a change in the incidence of a health endpoint. Inputs to health impact functions typically include:
- the change in ambient air pollution level,
- health effect estimate,
- the baseline incidence rate of the health endpoint, and
- the exposed population.
For example, in the case of a premature mortality health impact function, we might have the following: Mortality Change = Air Pollution Change * Mortality Effect Estimate * Mortality Incidence* Exposed Population
- Air Pollution Change. The air quality change is calculated as the difference between the starting air pollution level, also called the baseline, and the air pollution level after some change, such as that caused by a regulation. In the case of particulate matter, this is typically estimated in micrograms per meter cubed (μg/m3).
- Mortality Effect Estimate. The mortality effect estimate is an estimate of the percentage change in mortality due to a one unit change in ambient air pollution. Epidemiological studies provide a good source for effect estimates.
- Mortality Incidence. The mortality incidence rate is an estimate of the average number of people that die in a given population over a given period of time. For example, the mortality incidence rate might be the probability that a person will die in a given year. Mortality incidence rates and other health data are typically collected each country’s government. In addition, the World Health Organization is a good source for data.
- Exposed Population. The exposed population is the number of people affected by the air pollution reduction. The government census office is a good source for this information. In addition, private companies may collect this information and offer it for sale.
BenMAP also calculates the economic value of health impacts. After the calculation of the mortality change, you can value these premature deaths by multiplying the change in mortality reduction by an estimate of the value of a statistical life:
Value Mortality = Mortality Change * Value of Statistical Life
Value of Statistical Life: The value of a statistical life is the economic value placed on eliminating the risk of one premature death.
BenMAP also serves as a Geographic Information System (GIS), allowing users to create, utilize, and visualize maps of air pollution, population, incidence rates, incidence rate changes, economic valuations, and other types of data.
BenMAP can thus be used for a variety of purposes, including:
- Generating population/community level ambient pollution exposure maps;
- Comparing benefits associated with regulatory programs;
- Estimating health impacts and costs of existing air pollution concentrations.
- Estimating health benefits of alternative ambient air quality standards; and
- Performing sensitivity analyses of health or valuation functions, or of other inputs.
Who Would Find BenMAP Useful?
A wide range of persons can use BenMAP, including scientists, policy analysts, and decision makers. Advanced users can explore a wide range of options, such as using the map querying features and exploring the impacts of different health impact and valuation functions.