| tDay | is total number of working days during each time period |
| tPosD | is total number of possible working days during each time period derived from first and last day (if first day or last day is missing it is assumed that first day is 9/11/2001 and last day is 6/30/2002) |
| tshift | is the number of work shifts in a day (typically one work shift is 8 hours) |
| fdate | is a day-specific exposure-related factor accounting for severity of environmental and microenvironmental conditions on the date of each exposure event |
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.