Exposures to Airborne Particulate Matter and Adverse Perinatal Outcomes: A Biologically Plausible Mechanistic Framework for Exploring Potential Effect Modification by Nutrition

Abstract

ObjectivesThe 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.MethodsWe 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.ConclusionsProtecting 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.

Air pollution and low birth weight: a historical cohort study from Tehran

“…Although in a previous review study it was concluded that PM 10 had an effect on LBW [22], we found no significant association in this regard. The postulated mechanism for the effect of PM 10 is that PM 10 may bind to placental growth factor resulted in decreased fetal-placental exchange of oxygen and nutrients, nutrient and oxygen supply during gestation are key factors regulating fetal growth rate [23]. If this is true, a probable justification for this contrasting result is that there would necessarily be a threshold effect [8], but in our study the level of exposure to PM 10 may have been under the threshold level.…”

Are environmental pollutants risk factors for low birth weight?

“…Meanwhile, our findings disagree with those of Medeiros & Gouveia 8 and Bell et al 14 . Kannan et al 19 propose mechanisms resulting in low birth weight due to exposure to PM 10 .…”

Air Pollution and Adverse Pregnancy Outcome

“…Increased concentrations of DNA adducts have been found in the blood (Perera FP et al, 1992;Petruzzelli S et al, 1998) and placentas (Topinka J et al, 1997) of subjects living in polluted areas, and were also found to be related to birthweight . Maternal nutrition status can be acting as a effect modifier between exposures to airborne particulate matter and adverse perinatal outcomes (Kannan et al, 2006). Maternal pulmonary function has been linked to altered placental vascular function and growth retardation in asthmatic pregnancies (Bracken et al 2003;Clifton et al 2001;Schatz et al 1990).…”