• Blood lead concentration
• Child development/behavioral problems
• Intelligence quotient (IQ) scores
• Residential injuries

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.

The extension of this trial was essential to test the efficacy of the intervention on measures of children's cognitive abilities and behavioral problems that are not stable until 5 years of age and enhance our ability to show an effect of the injury intervention during the first 5 years of life, when children are particularly vulnerable to residential injury.

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, and growth delay in children.
• Higher lead exposure, measured during pregnancy and early childhood using maternal blood, cord blood, meconium and children's blood, will be associated with lower IQ scores and more behavioral problems for children with a maximal blood lead level < 5 mg/dL.
• Children in the lead treatment arm will have: blood lead that is 2.7 mg/dL lower, higher IQ scores, greater growth velocity, and fewer behavioral problems than children in the control group.
• Levels of lead in dust, soil and water will be significantly lower for housing units in the lead treatment arm compared with the injury control arm at 36 and 48 month home visits.
• A multifactorial, housing intervention will reduce residential injury by 30 percent among children in the injury treatment arm compared with those in the lead treatment arm.

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.

• Environmental Exposures
• Environmental Monitoring
• Child Development
• Disorders of Environmental Origin

• Procedure: Lead Hazard Control Intervention
• Procedure: Injury Hazard Control Intervention

• Other: random assignment to receive lead hazard reduction intervention
• Other: random assignment to receive injury hazard reduction intervention

• 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.
• Geraghty SR, Khoury JC, Morrow AL, Lanphear BP. Reporting individual test results of environmental chemicals in breastmilk: potential for premature weaning. Breastfeed Med. 2008 Dec;3(4):207-13.
• Phelan KJ, Khoury J, Xu Y, Lanphear B. Validation of a HOME Injury Survey. Inj Prev. 2009 Oct;15(5):300-6.

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