To the Editor.
—The study by Weitzman et al1 quantifying changes in children's blood lead levels in response to three different environmental interventions used in and around their homes is a valuable contribution to a field thirsting for quantitative data. Their data, combined with data generated from intervention studies in other locales, may be well used by thoughtful people to construct a cost-benefit analysis of household lead abatement that will guide US health and housing policy in the years to come. Weitzman et al deserve credit for a well-organized and scientifically sound study that in many ways will serve as a model for others.One apparent shortcoming, however, is the lack of a "no abatement" control group. (Because the study was confined to children with low levels of lead exposure [0.34 to 1.16 μmol/L (7 to 24 μg/dL)] in which abatement is of unproven value, one would not be