Derived variables: environment


A number of environmental variables relating to the period 1969 to 1973 were added to the LS database in the 1980s. They include measures of drinking water quality, air pollution and climate. They are often called the 'Royal Free variables', because the work was carried out by researchers at the Royal Free Hospital School of Medicine in London.

There are around 20 indicators and they may be attached to LS members present at the 1971 Census if they were then usually-resident in one of 228 urban areas. Other LS members do not have the indicators. The areas are 83 county boroughs, 32 London boroughs and 113 municipal boroughs and urban districts (32 of which are composites of adjacent small towns, which have been combined to produce a population of at least 50,000). A brief introduction includes information about the source of the data and references to previous studies using them.

The indicators were originally created for the British Regional Heart Study in the 1980s, and were used to examine the effects of water hardness and air pollution on cardiovascular mortality. The variables are still available in the LS database (although not currently listed in the Data Dictionary); consult your User Support Officer if you wish to use them.


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Last modified 12 October 2010