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Published on: March 20, 2021
Blood lead levels in a continuity clinic population
S E Holmes1, J E Drutz, G J Buffone
1Baylor College of Medicine, Houston, TX 77030, USA.
Insights
This study screened Houston children for lead toxicity, finding a 3.1% prevalence of elevated blood lead levels. The standard lead risk questionnaire missed 32% of cases, highlighting a need for improved screening methods.
Area of Science:
- Pediatric Environmental Health
- Toxicology
- Public Health
Background:
- Lead toxicity is a recognized cause of childhood morbidity, particularly affecting the central nervous system in young children.
- While not a recognized public health issue in Houston, low-level lead exposure effects are possible in local children.
Purpose of the Study:
- To identify asymptomatic lead toxicity cases in Houston children.
- To evaluate the effectiveness of the Centers for Disease Control's lead risk assessment questionnaire.
Main Methods:
- Quantitative blood lead levels were measured using Anodic Stripping Voltammetry.
- The lead risk assessment questionnaire was administered to children aged 9-72 months.
- 801 children were screened at a pediatric continuity clinic.
Main Results:
- 3.1% of children (25 out of 801) had elevated blood lead levels (10-19 µg/dL).
- No statistically significant differences were found based on age, sex, ethnicity, income, or zip code.
- Children in homes with pre-1960 peeling paint were more likely to have elevated lead levels (p = .045).
Conclusions:
- The prevalence of elevated blood lead in this urban, low-income Houston population was 3.1%, lower than CDC estimates.
- The lead risk questionnaire failed to identify 32% of children with elevated blood lead.
- Improved screening strategies, possibly including a revised questionnaire, are needed to accurately identify children at risk for lead toxicity.
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 problem in Houston, it is possible that children in the area suffer from low-level lead effects on the central nervous system.
Objectives:
To detect asymptomatic cases of lead toxicity in one population of Houston children and to assess the effectiveness of the lead risk questionnaire.
Design:
Venous blood samples for quantitative lead were analyzed utilizing 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 Children's Hospital.
Subjects:
All patients, ages 9-72 months, seen for routine care between December 1992 and June 1994 were screened once.
Results:
Blood lead levels were obtained on 801 children; all but 47 completed lead risk questionnaires. The mean age of the study group was 2.37 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 of < $20,000. They lived in 127 separate zip codes. Twenty-five (3.1%) patients had elevated blood lead, 21 between 10-14 micrograms/dL and 4 between 15-19 micrograms/dL. No patients had blood lead levels of > or = 20 micrograms/dL. No statistically significant differences were found between patients with blood lead < 10 micrograms/dL and those with > or = 10 micrograms/dL when comparing for age, sex, ethnicity, income, and zip code. Only those children living in or regularly visiting a pre-1960 home with peeling or chipping paint were significantly more likely to have elevated blood lead (p = .045).
Conclusion:
Although the majority of children in our setting were poor and urban, the prevalence of blood lead > or = 10 micrograms/dL was 3.1%, well below the estimated 17% quoted by the Centers for Disease Control in recommending stringent screening guidelines. The lead risk assessment questionnaire failed to identify 32% of children with elevated blood lead levels. Since this questionnaire is critical to screening populations at low risk for lead toxicity, it is important to determine whether a revised questionnaire or a more careful elicitation of parental responses will improve identification of those children at risk.
