Superfund Research Program
CBPI - Community-based Metal Exposure in Child Develpment and Hearing
Project Leader: Robert O. Wright
Grant Number: P42ES005947
Funding Period: 2000 - 2006
- Project Summary
Project Summary (2000-2006)
The CBPIR project is focused on neurodevelopmental health effects from manganese (Mn) and lead (Pb) exposure in the community surrounding the Tar Creek, Oklahoma Superfund site using community based research methodologies and partnerships. Exposure to Mn, particularly during pregnancy, may have broad public health implications as Mn is a common environmental contaminant. Chronic occupational Mn exposures have been associated with Parkinsonism and memory loss. Lower dose chronic environmental exposure to Mn has not been systematically studied, and potential adverse health effects from such environmental exposure, particularly among children, are poorly understood. The importance of this issue is underscored by the use of Mn as a gasoline additive, which is legal in the United States, although not yet in widespread use.
Enrollment in the CBPIR study began in November, 2002, and 243 mother infant pairs have been enrolled as of November 14, 2003. The investigators are now scheduling one year follow-up visits at which time they will conduct Bayley Scales of Infant Development. They have measured auditory brainstem evoked responses on all 243 infants and are currently analyzing and summarizing the hearing data. Dr. Wright's team has measured blood Mn and Pb concentrations in both infants and mothers at delivery and will also do so at the one year visit among the infants. The mean (STD) blood Mn levels among infants at time of delivery so far is 3.9 ug/dL (1.5 mg/dL); the range is 1.1 to 10.5 ug/dL. Mean (STD) maternal blood Mn levels were 2.1 ug/dL (0.7 ug/dL), range 0.9 to 4.6 ug/dL. These mean blood Mn level data are nearly identical to a recent report among mother-infant pairs in Montreal Canada, an area where Mn is routinely used as a gasoline additive. This suggests that the project results with respect to hearing and neurodevelopmental outcomes will be relevant to Mn exposure levels among communities in which Mn is used as a gasoline additive.
When the blood Mn data are broken down by race, there is evidence of increased exposure among minorities. Mean blood Mn levels among minority subjects (African American, Hispanic American and Native American) were higher than among white subjects, although the results only trended toward significance. Native Americans in particular eat foods grown locally and have unique cultural practices involving local plants and animals. Local environmental contamination with metals may have a disproportionately greater impact on Native American lifestyles than Western lifestyles. The researchers are currently working with a Native American community group - Local Environmental Action Demanded (L.E.A.D. agency) - to develop semi-structured questionnaires on traditional Native American lifestyles for incorporation into our exposure assessment for Mn and Pb.