HOME Study (Health Outcomes and Measures of the Environment Study)

Condition(s) targeted: Environmental Exposures; Environmental Monitoring; Child Development; Disorders of Environmental Origin

Intervention: Lead Hazard Control Intervention (Procedure); Injury Hazard Control Intervention (Procedure)

Phase: N/A

Status: Completed

Sponsored by: National Institute of Environmental Health Sciences (NIEHS)

Official(s) and/or principal investigator(s):
Bruce P Lanphear, MD, MPH, Principal Investigator, Affiliation: Children's Hospital Medical Center, Cincinnati

The goal of the HOME Study is to quantify the impact of low-level fetal and early childhood exposures to environmental toxicants (lead, mercury, pesticides, polychlorinated biphenyls [PCBs], environmental tobacco smoke, and alcohol) on child development (cognition, behavior, growth, and hearing). The HOME Study will also evaluate meconium as a biomarker for fetal exposure and test the effectiveness of home repairs to control lead hazards and injuries in early childhood.

Official title: Neurobehavioral Effects of Prevalent Neurotoxicants in Children: A Cohort Study of the Cincinnati Center for Children's Environmental Health

Study design: Prevention, Randomized, Single Blind, Active Control, Parallel Assignment, Safety/Efficacy Study

Primary outcome:

Blood lead concentration

Child development/behavioral problems

Intelligence quotient (IQ) scores

Hearing

Residential injuries

Detailed description: Objectives/Hypotheses: Epidemiologic and experimental data have established the adverse effects of numerous environmental toxicants, including lead, alcohol, mercury, PCB’s and environmental tobacco smoke (ETS), on children’s brain function. In utero exposure to these toxicants has been linked with cognitive deficits and behavioral problems. Lead exposure has been linked to specific behavioral problems, including conduct disorder and delinquency, and exposure to lead and ETS have been linked with mental retardation and attention deficit hyperactivity disorder (ADHD)-like features. Still, many studies linking environmental toxicants with neurobehavioral effect have only examined children with high exposures; there is emerging evidence that adverse effects of exposure to lead, mercury, and PCB’s occur at levels previously thought to be low. There are also data linking exposures to pesticides with adverse neurobehavioral effects, but the data are too sparse to draw any conclusions.

The ideal biomarkers for measuring in utero exposure to specific toxicants have not been established. Fetal exposure is typically measured with surveys, maternal blood, urine or

hair. Meconium - a chronic measure of in utero exposure - has only been validated as a

measure of cocaine and ETS exposure, but it offers numerous advantages, including a non-invasive method to simultaneously test for exposure to numerous toxicants. Still, it is unclear, whether conventional biomarkers or meconium is more predictive of the adverse effects associated with specific toxicants. For lead exposure, emerging data indicate that the investigators should emphasize primary prevention, but the safety and efficacy of lead hazard controls are uncertain, especially for children with lower blood lead concentrations. The investigators are testing the following hypotheses:

- In utero exposures measured by survey (alcohol and ETS), maternal and cord blood (lead

and mercury) maternal and cord serum (ETS), and urine (pesticides) are less predictive of in utero effects of prevalent toxicants, including cognition, behavior problems, growth and hearing, compared with the same toxicants in meconium.

- Prenatal and postnatal exposures to prevalent pesticides and ETS are associated with

adverse neurobehavioral effects, growth delay and hearing loss in children.

- Children in the Lead Hazard Reduction Group will have blood lead concentrations that are

2. 7 mcg/dL (30%) or lower at 36 months of age, significantly higher cognitive scores, less hearing loss, greater growth velocity, and fewer behavioral problems and developmental disorders, compared with those in the Control Group.

Approach: The investigators are conducting a longitudinal cohort study to examine the dose-response of low-level exposures (pre- and postnatal) to prevalent neurotoxins with neurobehavioral outcomes and specific development conditions, including conduct disorder and behaviors consistent with ADHD. They will also conduct a nested, randomized controlled trial to test the efficacy of lead hazard controls on blood lead concentrations and developmental conditions and the efficacy of injury hazard controls on injury incidence and severity.

Expected Results: This trial would be the first to attempt to validate meconium as a measure of exposure to numerous neurotoxicants and to test the efficacy of a residential lead and injury hazard control on blood lead concentration, neurobehavioral functioning, and injury incidence and severity.

Minimum age: 18 Years. Maximum age: N/A. Gender(s): Female.

Criteria:

Inclusion Criteria:

- Pregnancy

- Participating prenatal practice/clinic

- Participating hospital

Exclusion Criteria:

- Residence outside study area

- Plans to move outside study area within 1 year

- Home built after 1978

- Less than 18 years of age

- Beyond 19 weeks of gestation

- Diagnosis of diabetes

- Diagnosis of seizure disorder (taking anti-seizure medication)

- Diagnosis of thyroid disorder

- Diagnosis of AIDS or positive HIV test

- Diagnosis of bipolar disorder

- Diagnosis of schizophrenia

- Diagnosis of cancer resulting in radiation treatment or chemotherapy

Cincinnati Children's Environmental Health Center, Cincinnati, Ohio 45229, United States

Related publications:

Canfield RL, Henderson CR Jr, Cory-Slechta DA, Cox C, Jusko TA, Lanphear BP. Intellectual impairment in children with blood lead concentrations below 10 microg per deciliter. N Engl J Med. 2003 Apr 17;348(16):1517-26.

Phelan KJ, Khoury J, Kalkwarf H, Lanphear B. Residential injuries in U.S. children and adolescents. Public Health Rep. 2005 Jan-Feb;120(1):63-70.

Lanphear BP, Hornung R, Khoury J, Yolton K, Baghurst P, Bellinger DC, Canfield RL, Dietrich KN, Bornschein R, Greene T, Rothenberg SJ, Needleman HL, Schnaas L, Wasserman G, Graziano J, Roberts R. Low-level environmental lead exposure and children's intellectual function: an international pooled analysis. Environ Health Perspect. 2005 Jul;113(7):894-9.

Nagaraja J, Menkedick J, Phelan KJ, Ashley P, Zhang X, Lanphear BP. Deaths from residential injuries in US children and adolescents, 1985-1997. Pediatrics. 2005 Aug;116(2):454-61.

Starting date: March 2003
Last updated: March 22, 2006