Adverse organogenesis and predisposed long-term metabolic syndrome from prenatal exposure to fine particulate matter

Abstract

Exposure to fine particulate matter (PM) during pregnancy is associated with high risks of birth defects/fatality and adverse long-term postnatal health. However, limited mechanistic data are available to assess the detailed impacts of prenatal PM exposure. Here we evaluate fine PM exposure during pregnancy on prenatal/ postnatal organogenesis in offspring and in predisposing metabolic syndrome for adult life. Between days 0 and 18 of gestation, two groups of adult female rats (n = 10 for each) were placed in a dualexposure chamber device, one with clean ambient air (∼3 μg·m −3 ) and the other with ambient air in the presence of 100 to 200 μg·m −3 of ultrafine aerosols of ammonium sulfate. At birth (postnatal day 0, PND0), four males and four females were selected randomly from each litter to be nursed by dams, whereas tissues were collected from the remaining pups. At PND21, tissues were collected from two males and two females, whereas the remaining pups were fed either a high-or low-fat diet until PND105, when tissues were obtained for biochemical and physiological analyses. Maternal exposure to fine PM increased stillbirths; reduced gestation length and birth weight; increased concentrations of glucose and free fatty acids in plasma; enhanced lipid accumulation in the liver; and decreased endothelium-dependent relaxation of aorta. This lead to altered organogenesis and predisposed progeny to long-term metabolic defects in an age-, organ-, and sex-specific manner. Our results highlight the necessity to develop therapeutic strategies to remedy adverse health effects of maternal PM exposure on conceptus/postnatal growth and development.air pollution | pregnancy outcomes | postnatal health | metabolism W ith increasing urbanization, industrialization, and economic growth among developing/developed countries worldwide, air pollution has emerged as one of the greatest public health epidemics in the 21st century (1-5). According to the World Health Organization, 9 in 10 people breathe air containing high levels of pollutants, and one in nine of the global deaths is attributed to exposure to air pollution, reaching over total 7 million premature deaths each year (4, 5). Air pollution represents an environmental problem not only in developing countries but also in developed countries. For example, despite major progress made to improve air quality in the United States, ∼111 and 53 million people nationwide still inhabited places with pollutant levels exceeding the National Ambient Air Quality Standards and above the annual and/or 24-h particulate matter (PM) standard, respectively, in 2017 (6). There is accumulating evidence that several critical events in embryonic development during pregnancy are compromised by air pollution. Epidemiological studies have shown that maternal exposure to fine PM (particles with an aerodynamic diameter small than 2.5 μm, PM 2.5 ) is associated with high risks for preterm births, low birth weights, stillbirths, and adverse postnatal health conditions that include both pulmonary and nonp...

Remarkable nucleation and growth of ultrafine particles from vehicular exhaust

“…1 and SI Appendix, Fig. S3) (2), produced from NPF have potentially far-reaching human health outcomes (13,14). The adverse health effects of highly elevated UFPs have yet to be carefully considered in developing air quality standards (1,13,14).…”

“…Under favorable atmospheric conditions, nucleation-mode particles grow continuously to submicrometer (i.e., fine particulate matter smaller than 2.5 μm [PM 2.5 ]) or cloud condensation nuclei. Atmospheric measurements have shown ubiquitous NPF events under both pristine and urban conditions (1)(2)(3)(4)(5)8), with important societal implications (10)(11)(12)(13)(14). For example, high levels of UFPs formed under urban environments have been attributed to substantial enhancement in convection and precipitation (11).…”

“…For example, high levels of UFPs formed under urban environments have been attributed to substantial enhancement in convection and precipitation (11). Also, recent studies have demonstrated that maternal exposure to UFPs results in pulmonary immunosuppression and birth defects and fatalities in offspring, highlighting the necessity of accounting for these smallest particles when formulating air quality standards (13,14).…”

Interaction between succinic acid and sulfuric acid–base clusters

“…Currently, the indirect radiative forcing of aerosols represents the largest uncertainty in climate predictions (IPCC, 2013). In addition, ultrafine aerosols likely cause adverse human health outcomes (Rychlik et al, 2019;Wu et al, 2019). New particle formation (NPF) has been observed under diverse environmental conditions (Kulmala and Kerminen, 2008;Zhang et al, 2012;Wang et al, 2013Wang et al, , 2016Guo et al, 2014;Bianchi et al, 2016) and contributes up to half of the CCN population in the troposphere (Merikanto et al, 2009;Yue et al, 2011).…”

“…In addition, most previous theoretical studies focus on the enhancement effects of organic acids on the SA-H 2 O binary nucleation or the role of organic acids in clustering basic species such as ammonia or amines with hydration Xu et al, 2010a;Xu and Zhang, 2013;Elm et al, 2014;Weber et al, 2014;Zhu et al, 2014). Several recent studies have been conducted on the underlying mechanisms of organic acids in large pre-nucleation clusters (e.g., ammonia/amine-containing ternary nucleation) (Xu et al, 2010b;Xu and Zhang, 2012;Elm et al, 2016a;Zhang et al, 2017), but most of these studies treated the clusters without the consideration of hydration. Because of the ubiquitous presence of water (W) in the atmosphere and its much higher abundance than other nucleation precursors, the hydration effect on aerosol nucleation is significant (Loukonen et al, 2010;Xu and Zhang, 2013;Henschel et al, 2014Henschel et al, , 2016Zhu et al, 2014).…”