December 12th, 2017
The Treatment of Lead-exposed Children (TLC)-Clinical Trial is investigating the potential benefits of the use of the oral chelating agent “succimer” for the treatment of moderately lead poisoned children (PbB 20-44 Fg/dL) aged 12 to 32 months at the start of treatment. The Trial has four Clinical Centers nationwide and is sponsored by the National Institute of Environmental Health Sciences (NIEHS). The main outcome variable is the child’s neurodevelopmental status 36 months and 84 months after the start of treatment (based on a recent extension). The primary TLC research question is whether or not treatment with succimer offers any benefit in addition to that which might occur with reduction of lead exposure in the home. By design, all houses of TLC Trial participants (treatment and placebo groups) received at minimum a professional cleaning prior to the start of treatment so that children could be treated on an outpatient basis and no child would be treated with uncontrolled lead exposure in the home. The Baltimore Clinical Center of the TLC Trial performed various interim control and repair interventions in the homes of TLC children in addition to professional cleaning. It was not the objective of the TLC Trial to carry out or oversee comprehensive lead-based paint abatement activities. However, in some cases, TLC houses in the Baltimore Clinical Center received more intensive interventions using special forgivable state loan funds for lead-based paint abatement reserved for the Trial by the Maryland Department of Housing and Community Development (MDHCD). This report is based on wipe dust testing performed before, immediately after, and two years after the implementation of various interventions in a subset of 62 homes of the 213 children enrolled in the Baltimore Clinical Center. Dust samples were collected from floors, window sills, and window wells (troughs) in each house at each campaign and from walls in kitchens and bedrooms two years after intervention.