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Persistent chemicals found in breast milk and their possible interactions
Hana R Pohl1, Peter McClure, Christopher T De Rosa
1Agency for Toxic Substances and Disease Registry (ATSDR), U.S. Department of Health and Human Services, Atlanta, Georgia 30333, GA, USA.
Environmental Toxicology and Pharmacology
|July 26, 2011
Summary
Persistent chemicals like dioxins and PCBs in breast milk may pose health risks. Current studies are insufficient for assessing mixture hazards, recommending component-based methods for accurate risk evaluation.
Area of Science:
- Environmental Health
- Toxicology
- Epidemiology
Background:
- Persistent chemicals including chlorinated dibenzo-p-dioxins (CDDs), hexachlorobenzene, p,p'-DDE, methylmercury, and polychlorinated biphenyls (PCBs) are detected in human breast milk.
- Epidemiological studies suggest potential mild neurodevelopmental deficits linked to exposure to these biopersistent chemicals.
- Existing studies often do not analyze the full mixture, limiting their utility for comprehensive hazard assessments.
Purpose of the Study:
- To review data on the joint toxic actions of a specific mixture of persistent chemicals found in breast milk following oral exposure.
- To evaluate the adequacy of current data for exposure-based hazard assessments of chemical mixtures.
- To recommend appropriate methodologies for assessing the risks associated with complex environmental exposures.
Main Methods:
- Literature review focusing on oral exposure data for CDDs, hexachlorobenzene, p,p'-DDE, methylmercury, and PCBs.
- Evaluation of existing epidemiological and animal studies concerning the interactive toxic effects of these chemicals.
- Assessment of component-based methodologies, including binary weight-of-evidence, hazard index (HI), and target-organ toxicity dose (TTD) approaches.
Main Results:
- Weight-of-evidence analysis of limited animal data suggests that interactions among the studied chemicals do not currently warrant concern for deviations from additivity.
- Current epidemiological studies are not directly applicable for exposure-based hazard assessments of this specific chemical mixture due to incomplete analysis.
- Data on the joint toxic actions of this mixture are considered inadequate for definitive risk characterization.
Conclusions:
- Component-based methodologies are recommended for accurate exposure-based hazard assessments of persistent chemical mixtures in breast milk.
- Further research is needed to adequately assess the public health risks posed by environmental mixtures of these chemicals.
- Integrating exposure data with community health outcomes and concerns is crucial for comprehensive risk management.
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