Exposures to Airborne Particulate Matter and Adverse Perinatal Outcomes: A Biologically Plausible Mechanistic Framework for Exploring Potential Effect Modification by Nutrition
Srimathi Kannan,1Dawn P Misra,2 J. Timothy Dvonch,3 and Ambika Krishnakumar4 1Department of Environmental Health Sciences, Human Nutrition Program, 2Department of Health Behavior and Health Education, and 3Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA; 4Department
of Child and Family Studies, Syracuse University, College of Human Studies and Health Professions, Syracuse, New York, USA Abstract Objectives: The specific objectives are threefold: to describe the biologically plausible mechanistic pathways by which exposure to particulate matter (PM) may lead to the adverse perinatal outcomes of low birth weight (LBW) , intrauterine growth retardation (IUGR) , and preterm delivery (PTD) ; review the evidence showing that nutrition affects the biologic pathways ; and explain the mechanisms by which nutrition may modify the impact of PM exposure on perinatal outcomes.
Methods: We propose an interdisciplinary conceptual framework that brings together maternal and infant nutrition, air pollution exposure assessment, and cardiopulmonary and perinatal epidemiology. Five possible albeit not exclusive biologic mechanisms have been put forth in the emerging environmental sciences literature and provide corollaries for the proposed framework.
Conclusions: Protecting the environmental health of mothers and infants remains a top global priority. The existing literature indicates that the effects of PM on LBW, PTD, and IUGR may manifest through the cardiovascular mechanisms of oxidative stress, inflammation, coagulation, endothelial function, and hemodynamic responses. PM exposure studies relating mechanistic pathways to perinatal outcomes should consider the likelihood that biologic responses and adverse birth outcomes may be derived from both PM and non-PM sources (e.g., nutrition) . In the concluding section, we present strategies for empirically testing the proposed model and developing future research efforts.
Key words: air pollution, biomarkers, birth outcomes, cardiovascular disease, nutrition, particulate matter. Environ Health Perspect 114:1636-1642 (2006) . doi:10.1289/ehp.9081 available via http://dx.doi.org/ [Online 17 August 2006] Address correspondence to S. Kannan, Department of Environmental Health Sciences, Human Nutrition Program, University of Michigan, Room 6338, SPH-I (Tower) , School of Public Health, Ann Arbor, MI 48109-2029 USA. Telephone: (734) 936-1629. Fax: (734) 763-8095. E-mail: kannans@umich.edu The authors declare they have no competing financial interests. Received 9 February 2006 ; accepted 16 August 2006. The full version of this article is available for free in HTML or PDF formats. |