Epidemiological monitoring of environmental lead exposures in California State Hospitals

Abstract

Blood lead screening of 8062 state hospital residents in California revealed 143 residents with excessive lead levels (≥ 30 μg/dL). This screening was part of the Childhood Lead Project and was performed in 1978. The purpose of this study was to identify “critical” lead sources in California State Hospitals. Accurate identification is crucial if subsequent abatement programs are to be effective. The strategy involved the following sequence of steps: 1) Selection of cases based on blood lead and erythrocyte protoporphyrin screening. 2) Determination of pica habits and environmental exposures through interviews with ward's staff and/or parents. 3) Measurement of lead levels in environmental samples reflecting exposures. 4) Interpreting these data in order to identify critical lead sources. 5) Reducing exposure to critical lead sources. 6) Following up of cases and controls to validate the effects of this strategy. A group of 36 lead-burdened cases with pica (30–60 μg Pb/dL blood) and 36 matched controls (PbN less than 20 μg/dL) were selected from among the developmentally disabled residents of two California State Hospitals. These subjects were studied in order to identify the lead sources to which they were exposed and to abate the major ones. Three major lead sources were found in the state hospitals: wall and furniture paints (100–45,400 μg Pb/g paint); surface soil (33–570 μg Pb/g soil); magazine and wrapping paper (10–2600 μg Pb/g paper). In many cases an educational format was presented to all involved staff. The results have indicated a trend towards lower lead intake by the lead-burdened cases. In one of the two hospitals a “lead-free unit” had been established. All the lead-burdened cases were transferred to this unit in August 1981. A few months later the blood lead levels of all the cases dropped below 30 μg/dL. Initial epidemiological monitoring indicated where there were preventable hazards, which abatement efforts succeeded in reducing. Further monitoring of such problems is indicated in this and other developmentally-disabled populations.