BLOOD LEAD LEVELS IN A CONTINUITY CLINIC POPULATION

Introduction: Lead toxicity is well recognized as a significant cause of morbidity in children, especially those under the age of six years. While lead toxicity has not been recognized as a public health proble m in Houston, it is possible that children in the area suffer from low -level lead effects on the central nervous system. Objectives: To dete ct asymptomatic cases of lead toxicity in one population of Houston ch ildren and to assess the effectiveness of the lead risk questionnaire. Design: Venous blood samples for quantitative lead were analyzed util izing the Anodic Stripping Voltameter. The Centers for Disease Control 's lead risk assessment questionnaire was administered to each patient . Setting: Baylor College of Medicine Continuity Clinic at Texas Child ren's Hospital. Subjects: All patients, ages 9-72 months, seen for rou tine care between December 1992 and June 1994 were screened once. Resu lts: Blood lead levels were obtained on 801 children; all but 47 compl eted lead risk questionnaires. The mean age of the study group was 2.3 7 years (SD 1.84) and they were 54% male. They were 39% Hispanic, 39% Black, and 18% White. Eighty-eight percent reported an annual income o f < $20,000. They lived in 127 separate zip codes. Twenty-five (3.1%) patients had elevated blood lead, 21 between 10-14 mu g/dL and 4 betwe en 15-19 mu g/dL. No patients had blood lead levels of greater than or equal to 20 mu g/dL. No statistically significant differences were fo und between patients with blood lead < 10 mu g/dL, and those with grea ter than or equal to 10 mu g/dL when comparing for age, sex, ethnicity , income, and zip code. Only those children living in or regularly vis iting a pre-1960 home with peeling or chipping paint were significantl y more likely to have elevated blood lead (p = .045). Conclusion: Alth ough the majority of children in our setting were poor and urban, the prevalence of blood lead greater than or equal to 10 mu g/dL was 3.1%, well below the estimated 17% quoted by the Centers for Disease Contro l in recommending stringent screening guidelines. The lead risk assess ment questionnaire failed to identify 32% of children with elevated bl ood lead levels. Since this questionnaire is critical to screening pop ulations at low risk for lead toxicity, it is important to determine w hether a revised questionnaire or a more careful elicitation of parent al responses will improve identification of those children at risk.