PREVALENCE OF LEAD-POISONING IN A SUBURBAN PRACTICE

Background. The purpose of this study was to determine the prevalence of elevated blood lead levels (EBLLs, lead greater than or equal to 10 mu g/dL [0.48 mu mol/L]) in a suburban family practice setting and to assess the utility of a questionnaire as an alternative to universal screening in identifying individuals with EBLL in a low-risk population. Methods. Parents bringing children aged 1 through 3 years into the office for any type of visit were offered the opportunity to complete a questionnaire concerning risk for lead poisoning and to obtain free blood lead testing for their child. No child in this study had previously been tested for lead toxicity. The lead levels found on testing were correlated with the questionnaire results. Results. Two hundred thirty-two children with an average age of 20 months were tested. Blood lead levels ranged from 0 to 53 mu g/dL (2.56 mu mol/L). Elevated blood lead levels were found in 5.6% of the study population. The five questions suggested by the Centers for Disease Control and Prevention (CDC) were taken as a group, and any ''yes'' or ''don't know'' response was considered a risk factor. These questions had a sensitivity of 84.6% and a specificity of 41.6% in identifying children with EBLL. An additional question regarding residence in a home built before 1960 (or not knowing the age of the home) was a better screening test for EBLL (sensitivity 92.3%, specificity 57.1%) than the five CDC questions. Lower household income was associated with an EBLL, but sex, race, and home location (urban, suburban, rural) were not. Conclusions. Risk-assessment questionnaires are useful tools in selecting children who are at risk for an EBLL from low-risk populations. Comparison of this study with similar studies suggests that the most useful questions for this purpose may vary according to location. In this and other studies to date, however, questionnaires show less than 100% sensitivity in identifying children with EBLL.