AQDM-Variables: AQDM Variables
In ebailey78/raqdm: Access data from U.S. EPA's Air Quality Data Mart in R

U.S. EPA's AQDM requires that you define 3 things in order to request data from the service:

They provide several options to define each of these, but some definition of each is required.

You can define your parameters of interest in two ways:

Paramater Class: pc (Parameter Class) allows you to select a set of parameters that you are interested in. (e.g., HAPS or CRITERIA)
Parameter Code: param (Parameter Code) allows you to select a specific parameter that you are interesting in. (e.g., 44201 for Ozone or 45201 for Benzene)

You can define your time period by the sampling date, the change date, or both.

Sampling Date: Use bdate (Begin Date) and edate (End Date)to define the beginning and end of the sampling date range in which you are interested. AQDM requires a specific format for dates but as long as you use an unambiguous date format raqdm will convert your dates to the proper format before sending the query.
Change Date: Use cbdate (Change Begin Date) and cedate (Change End Date) to define the beginning and end of the change date range in which you are interested. AQDM requires a specific format for dates but as long as you use an unambiguous date format raqdm will convert your dates to the proper format before sending the query.

AQDM offers many ways to define a geography of interest.

State/County/Site: You can specify a state (State code), county (County code), and site (Site ID) to define your geographic area of interest. You need all the less-specific variables in order to use the more specific variables. So to request data from a specific site you must provide state and county. To request all data from a specfic county, you must provide state also.
CBSA: You can request all data from a Core-Based Statistical Area using the cbsa variable.
CSA: You can request all data from a Consolidated Statistical Area using the csa variable.
Latitude/Longitude: You can request all data from within a geographic bounding box. Use minlat (Minimum Latitude), maxlat (Maximum Latitude), minlon (Minimum Longitude), and maxlon (Maximum Longitude) to define the bounding box. All latutudes and longitudes should be in decimal degrees.

There are several other variables that you can use in your AQDM query.

Username/Password: user (Username) and pw (Password) are required to access AQDM.
Output Format: format defines the type of output you want. This defaults to DMCSV. This can affect the type of data you get back from AQDM, though raqdm will convert all returned values to data.frame.
Duration: dur allows you to request a specific a sample duration. If omitted, AQDM will return all available data.
FRM Only: frmonly allows you to request only FRM/FEM data be returned in the query. If omitted, all available data will be returned.