Maternal exposure to fine particulate matter (PM2.5) and pregnancy outcomes: a meta-analysis

Abstract

A growing body of evidence has investigated the association between maternal exposure to PM2.5 (particulate matter with aerodynamic diameter 2.5 μm) during pregnancy and adverse pregnancy outcomes. However, the results of those studies are not consistent. To synthetically quantify the relationship between maternal exposure to PM2.5 during pregnancy and pregnancy outcomes (the change in birth weight, low birth weight (LBW), preterm birth (PTB), small for gestational age (SGA), and stillbirth), a meta-analysis of 25 published observational epidemiological studies that met our selection criteria was conducted. Results suggested a 10 μg/m(3) increase in PM2.5 was positively associated with LBW (odds ratio (OR) = 1.05; 95 % confidence interval (CI), 1.02-1.07), PTB (OR = 1.10; 95 % CI, 1.03-1.18), and SGA (OR = 1.15; 95 % CI, 1.10-1.20) based on entire pregnancy exposure, and pooled estimate of decrease in birth weight was 14.58 g (95 % CI, 9.86-19.31); however, there was no evidence of a statistically significant effect of per 10 μg/m(3) increase in PM2.5 exposure on the risk of stillbirth (OR = 1.18; 95 % CI, 0.69-2.04). With respect to three different gestation periods, no significant risks were found in PTB, stillbirth, and the first trimester on the change of birth weight with a 10 μg/m(3) increase in PM2.5. In this study, a comprehensive quantitative analysis of the results show that PM2.5 can increase the risk of LBW, PTB, and SGA; pregnant women need to take effective measures to reduce PM2.5 exposure.

Fetal growth and maternal exposure to particulate air pollution -- More marked effects at lower exposure and modification by gestational duration

“…For SGA our results are consistent with a recent meta-analysis (Zhu et al, 2015) which found a positive association between SGA and entire pregnancy exposure to particulate matter with Fig. 1.…”

Short-term exposure to particulate air pollution and risk of myocardial infarction: a systematic review and meta-analysis

“…Just as its small size and long residence time in air, more likely adsorbing various harmful substances in the air, PM 2.5 can enter the depths of human respiratory tract and participate in the blood circulation (Kreyling et al 2002;Billet et al 2007;Zhu et al 2015). The results verified the statement that PM 2.5 tends to be more harmful to human than other air pollutants including PM 10 .…”

“…If a study did not show enough quantitative data, we would contact the author by sending an email, and the study would be excluded without getting an answer. To avoid involving the same or overlapping dataset, when the same patient population in a region was included in several publications, only the study with the largest number of observations and/or the longest study period was included in the meta-analysis (Zhu et al 2015). For example, results from Zanobetti and Schwartz (2006) were chosen over Peters et al (2001) in the same region, for the former reporting a longer study period.…”

“…diameter ≤10 μm (PM10) and fine ambient particulate matter, aerodynamic diameter ≤2.5 μm (PM2.5) (Barnett et al 2006;Hodas et al 2013; Bard et al 2014). Especially, the composition of PM2.5 always changes for emitting from a variety of sources and varies temporally and spatially (Heo et al 2014;Zhu et al 2015). Furthermore, on account of the large specific surface area, its small size and long residence time in air, more likely adsorbing various harmful substances in the air, PM2.5 can enter the depths of human respiratory tract and participate in the blood circulation; therefore, it tends to be more harmful to human than other air pollutants (Kreyling et al 2002;Billet et al 2007;Zhu et al 2015).…”

“…Especially, the composition of PM2.5 always changes for emitting from a variety of sources and varies temporally and spatially (Heo et al 2014;Zhu et al 2015). Furthermore, on account of the large specific surface area, its small size and long residence time in air, more likely adsorbing various harmful substances in the air, PM2.5 can enter the depths of human respiratory tract and participate in the blood circulation; therefore, it tends to be more harmful to human than other air pollutants (Kreyling et al 2002;Billet et al 2007;Zhu et al 2015). An elevated risk of inflammation, oxidative stress, increased blood coagulation, cardiac arrhythmia, changed vascular function, or others could be the potential mechanistic pathways by which exposure to ambient particulate matter air pollution may result in onset of MI (Mills et al 2009;Brook et al 2010;Mustafic et al 2012).…”