|Variable on database||Comment or further description||Derived Variables|
|Unique key||TEBA randomly assigned no. (Not personal ID number).|
|Date of birth||Age|
|Racial ascription||Four category classification formalised under apartheid, and in continuing usage for some official purposes – Asian, black, coloured, white.|
|Origin||Country and district/region/province of office at which recruited or registered for a given contract.||Origin at first contract on the database|
|Contract start date||
Number of contracts.|
Start date of first contract.
Start dates of returning contract.
|Contract end date||
End date of first contract.|
End dates of returning contract.
|Contract duration (days)||Difference between contract end date and contract start date.||Cumulative service across all contracts.|
|Contract duration (months)||Days or weeks rounded up or down to the nearest whole number of months, e.g. 35 days = 1 month.||Cumulative service across all contracts.|
|Commodity sector||Gold, platinum group metals, coal, “other” (antimony, asbestos, chrome, copper, diamond, granite, iron, lead, lime, tin, vanadium)a .||Commodity sector of longest cumulative service for an individual.|
|Occupational risk category||Underground, “surface risk”, “surface non-risk”. Surface definition based on exposure to hazardous airborne agents.||Occupational risk category of longest cumulative service for an individual|
|Employment status||Mine employee versus “contractor”. See text for further definition.||Exclusively mine employee versus contractor “ever” on TEBA database|