June 8, 2005
Phthalates Found in Infants Treated in NICUs that Use Devices Containing Phthalates
Boston, MA - Researchers from the Harvard School of Public Health (HSPH), two Harvard-affiliated hospitals, and the U.S. Centers for Disease Control and Prevention found that infants in neonatal intensive care units (NICUs) whose care entailed the use of medical devices containing di(2-ethylhexyl) phthalate (DEHP) had high levels of this compound in their bodies. In addition, in one of the first reports of its kind, the investigators found among the infants a direct relationship between these levels and the intensity at which DEHP-containing medical devices were used in their treatment. The findings appear in the on-line issue of Environmental Health Perspectives. (Full article)
DEHP is used to soften and plasticize the rigid polymer polyvinyl chloride (PVC). In PVC plastic, DEHP readily migrates out of the plastic into blood and fat-containing solutions in contact with the plastic, a phenomenon observed with blood stored in PVC bags. The DEHP may also migrate out of the plastic into the body from catheters and tubing used in medical treatments. The body metabolizes DEHP into mono-(2-ethylhexyl) phthalate (MEHP) which can be measured in urine and used as an indicator of the level of exposure to DEHP. In laboratory animals, MEHP has been shown to disrupt reproductive tract development and function following in-utero or early lifetime exposure.DEHP is found in a variety of medical products and devices used in NICUs, including examination gloves, bags containing blood, plasma, intravenous (IV) fluids and tubing and other products associated with the delivery of fluids, nutrients, and air to NICU infants. The researchers assessed the use of DEHP-containing products in the care of 54 infants admitted to one of two NICUs, and examined the intensity of use of these products in relation to levels of MEHP in the infants' urine.
On average, the levels of MEHP in the infants' urine were manyfold higher than those observed in other studies of U.S. children and adults. Moreover, there was a direct relationship between urinary MEHP levels and the intensiveness of medical product use. Urinary MEHP levels among infants with high DEHP-containing product use were five times as great as levels among infants with low DEHP product use; urinary MEHP levels among infants with medium DEHP product use were twice as great.
Dr. Howard Hu, principal investigator and HSPH professor of occupational and environmental medicine said, "Our study not only demonstrates that infants in the NICU are exposed to demonstrably high levels of DEHP, but we have also clearly linked the intensity of DEHP product use with the amount of DEHP that enters infants' bodies." Principal collaborator, Dr. Russ Hauser, HSPH associate professor of occupational health added, "Based on our results and what we know about the toxicity of DEHP from studies in laboratory animals, we need to better understand whether there are potential health risks of high DEHP exposure in NICU babies." Both investigators note that although the use of these medical products is lifesaving for NICU infants, there are alternative products available that contain little or no phthalates, and as a precaution, NICUs should consider a transition to their use.
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