Lead was banned from use in both interior and exterior house paint in 1978. The lead content of paint manufactured prior to 1950 was generally higher than the lead content of paint manufactured between 1950 and 1978. Moreover, older homes (i.e., those build before 1950) are more likely to be deteriorating, producing paint chips and dust that may be ingested by young children.

The Mayo Clinic website discussing children's health and lead poisoning notes:

The 1991 Field Representative's Manual noted that the survey section on environmental health was intended "[t]o provide baseline data on the state of the nation's environmental health, including testing for lead and radon for the 'Year 2000 Objectives of the Nation.'"

The 1993 Manual described the Y2K supplement as "primarily to measure progress toward reaching objectives for the health of the Nation as determined by the Department of Health and Human Services for the Year 2000," while its environmental health component was to provide "current data on the state of the nation's environmental health, including testing for lead and radon."

The 1998 Manual specified a concrete environmental health goal: "to test at least 50% of the homes built before 1950 for the presence of lead paint."

The 2002 Survey Description reported that