Seasonal variation of endocrine disrupting potentials of pollutant mixtures associated with various size-fractions of inhalable air particulate matter

Gestational exposure to wildfire PM2.5 and its specific components and the risk of gestational hypertension and eclampsia in the southwestern United States

In the southwestern United States, the frequency of summer wildfires has elevated ambient PM2.5 concentrations and rates of adverse birth outcomes. Notably, hypertensive disorders in pregnancy (HDP) constitute a significant determinant associated with maternal mortality and adverse birth outcomes. Despite the accumulating body of evidence, scant research has delved into the correlation between chemical components of wildfire PM2.5 and the risk of HDP. Derived from data provided by the National Center for Health Statistics, singleton births from >2.68 million pregnant women were selected across 8 states (Arizona, AZ; California, CA, Idaho, ID, Montana, MT; Nevada, NV; Oregon, OR; Utah, UT, and Wyoming, WY) in the southwestern US from 2001 to 2004. A spatiotemporal model and a Goddard Earth Observing System chemical transport model were employed to forecast daily concentrations of total and wildfire PM2.5-derived exposure. Various modeling techniques including unadjusted analyses, covariate-adjusted models, propensity-score matching, and double robust typical logit models were applied to assess the relationship between wildfire PM2.5 exposure and gestational hypertension and eclampsia. Exposure to fire PM2.5, fire-sourced black carbon (BC) and organic carbon (OC) were associated with an augmented risk of gestational hypertension (ORPM2.5 = 1.125, 95 % CI: 1.109,1.141; ORBC = 1.247, 95 % CI: 1.214,1.281; OROC = 1.153, 95 % CI: 1.132, 1.174) and eclampsia (ORPM2.5 = 1.217, 95 % CI: 1.145,1.293; ORBC = 1.458, 95 % CI: 1.291,1.646; OROC = 1.309, 95 % CI: 1.208,1.418) during the pregnancy exposure window with the strongest effect. The associations were stronger that the observed effects of ambient PM2.5 in which the sources primarily came from urban emissions. Social vulnerability index (SVI), education years, pre-pregnancy diabetes, and hypertension acted as effect modifiers. Gestational exposure to wildfire PM2.5 and specific chemical components (BC and OC) increased gestational hypertension and eclampsia risk in the southwestern United States.

Atmospheric endocrine disruptors: A systematic review on oestrogenic and androgenic activity of particulate matter

The alarming human health effects induced by endocrine disruptors (ED) have raised the attention of public opinion and policy makers leading worldwide to regulations that are continuously improved to reduce exposure to them. However, decreasing the exposure levels is challenging because EDs are ubiquitous and exposure occurs through multiple routes. The main exposure route is considered ingestion, but, recently, the inhalation has been hypothesized as an important additional route. To explore this scenario, some authors applied bioassays to assess the endocrine activity of air. This review summarizes for the first time the applied methods and the obtained evidences about the in vitro endocrine activity of airborne particulate matter (PM) collected outdoor. Among the bioassay endpoints, (anti)oestrogenic and (anti)androgenic activities were selected because are the most studied endocrine activities. A total of 24 articles were ultimately included in this review. Despite evidences are still scarce, the results showed that PM can induce oestrogenic, antioestrogenic, androgenic and antiandrogenic effects, suggesting that PM has an endocrine disrupting potential that should be considered because it could represent a further source of exposure to EDs. Although it is difficult to estimate how much inhalation can contribute to the total burden of EDs, endocrine activity of PM may increase the human health risk. Finally, the results pointed out that the overall endocrine activity is difficult to predict from the concentrations of individual pollutants, so the assessment using bioassays could be a valuable additional tool to quantify the health risk posed by EDs in air.

Can oestrogenic activity in air contribute to the overall body burden of endocrine disruptors?

Endocrine disruptors (EDCs) are emerging contaminants that are harmful to health. Human exposure occurs mainly through ingestion or dermal contact, but inhalation could be an additional exposure route; therefore, this study was conducted to evaluate the oestrogenic activity of airborne particulate matter (PM). Outdoor PM was collected for a year in five Italian sites and extracted with organic solvents (four seasonal extracts/site). The oestrogenic activity was assessed using a gene reporter assay (MELN), and the risk to human health through inhalation was quantified using the results. Moreover, extracts were analysed to assess cytotoxicity (WST-1 and LDH assays) on human bronchial cells (BEAS-2B). The extracts induced a significant cytotoxicity and oestrogenic activity. Oestrogenic activity showed a seasonal trend and was correlated with concentrations of benzo(a)pyrene and toxic equivalency factor. Although a low inhalation cancer risk was found, this study confirmed that oestrogenic activity in air could contribute to overall health risks due to EDC exposure.

Personal airborne chemical exposure and epigenetic ageing biomarkers in healthy Chinese elderly individuals: Evidence from mixture approaches

BACKGROUND

Air pollution is associated with accelerated biological ages determined by DNA methylation (DNAm) patterns, imposing further risks of age-related adverse effects. However, little is known about the independent and joint effects of exposure to gaseous organic chemicals that may share a common source.

METHODS

We conducted a panel study with the 3-day exposure assessment monthly among 73 Chinese healthy elderly people aged 60 to 69 years in Jinan, Shandong province during September 2018 to January 2019.Exposure to 26 ambient organic chemical contaminants were measured by wearable passive samplers, including volatile organic compounds, polycyclic aromatic hydrocarbons (PAHs), phthalates (PAEs), nitroaromatics (NIs), polybrominated diphenyl ethers, chlorinated hydrocarbons, and organophosphate esters. The Illumina MethylationEPIC BeadChip was used to measure DNA methylation levels in blood samples, and based on which, epigenetic ageing biomarkers, including Hannum clock, Horvath clock, DNAm PhenoAge, DNAm GrimAge, and DNAm estimator of telomere length (DNAmTL) were calculated. Linear mixed effect models were used to estimate the linear associations between 3-day personal chemical exposure and the epigenetic biomarkers, Weighted quantile sum (WQS) regression and the Bayesian kernel machine regression (BKMR) model were further used to evaluate the effect of chemical mixtures.

RESULTS

Multiple linear mixed effects regression models showed that DNAmPhenoAge acceleration was significantly and positively associated with exposure to PAEs, NIs, and PAHs in healthy elderly individuals. Both WQS regression and BKMR models showed a significant positive association with DNAmPhenoAge acceleration with chemical exposures, in which the effect of di-n-butyl phthalate exposure showed the greatest importance.

CONCLUSION

These findings suggest that exposure to a mixture of airborne chemicals significantly increase the acceleration of the epigenetic biomarker of phenotypic age. These findings serve to identify toxic chemicals in the air and facilitate the evaluation of their potentially severe health effects.

Toxicity and endocrine-disrupting potential of PM2.5: Association with particulate polycyclic aromatic hydrocarbons, phthalate esters, and heavy metals

The adverse effects of fine atmospheric particulate matter with aerodynamic diameters of ≤2.5 μm (PM_2.5) are closely associated with particulate chemicals. In this study, PM_2.5 samples were collected from highway and industry sites in Hangzhou, China, during the autumn and winter, and their cytotoxicity and pulmonary toxicity and endocrine-disrupting potential (EDP) were evaluated in vitro and in vivo; the particulate polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs), and heavy metals were then characterized. The toxicological results suggested that the PM_2.5 from highway site induced higher cytotoxicity (cell viability inhibition, intracellular oxidative stress, and cell membrane injury) and pulmonary toxicity (inflammatory response (IR) and oxidative stress (OS)) than the samples from industry site, while the PM_2.5 from industry site exhibited higher EDP (estrogenic and anti-androgenic activity). The cytotoxicity and pulmonary toxicity of PM_2.5 in the winter were higher than those in the autumn, while no seasonal difference in the endocrine-disrupting potential was observed (p > 0.05). The Pearson correlation analysis between the biological effects and particulate chemicals revealed that the PM_2.5-induced inflammatory response and oxidative stress were closely associated with the particulate PAHs and heavy metals (Pearson correlation coefficients: r_{IR, PAHs} = 0.822-0.988, r_{IR, heavy metals} = 0.895-0.971, r_{OS, PAHs} = 0.843-0.986, and r_{OS, heavy metals} = 0.887-0.933), while particulate di (2-ethylhexyl)phthalate (DEHP) substantially contributed to the EDP of PM_2.5 (r_{EDP, DEHP} = 0.981). This study indicated that the toxicity and EDP of PM_2.5 could vary with the surrounding environment and season, which was closely associated with the variations of particulate chemicals. Further studies are needed to clarify the associations between the harmful effects of PM_2.5 and other contributing factors.

Current advances and future challenges of AIoT applications in particulate matters (PM) monitoring and control

Air pollution is at the center of pollution-control discussion due to the significant adverse health effects on individuals and the environment. Research has shown the association between unsafe environments and different sizes of particulate matter (PM), highlighting the importance of pollutant monitoring to mitigate its detrimental effect. By monitoring air quality with low-cost monitoring devices that collect massive observations, such as Air Box, a comprehensive collection of ground-level PM concentration is plausible due to the simplicity and low-cost, propelling applications in agriculture, aquaculture, and air quality, water resources, and disaster prevention. This paper aims to view IoT-based systems with low-cost microsensors at the sensor, network, and application levels, along with machine learning algorithms that improve sensor networks' precision, providing better resolution. From the analysis at the three levels, we analyze current PM monitoring methods, including the use of sensors when collecting PM concentrations, demonstrate the use of IoT-based systems in PM monitoring and its challenges, and finally present the integration of AI and IoT (AIoT) in PM monitoring, indoor air quality control, and future directions. In addition, the inclusion of Taiwan as a site analysis was illustrated to show an example of AIoT in PM-control policy-making potential directions.

Prenatal Ambient Ultrafine Particle Exposure and Childhood Asthma in the Northeastern United States

Rationale: Ambient ultrafine particles (UFPs; with an aerodynamic diameter < 0.1 μm) may exert greater toxicity than other pollution components because of their enhanced oxidative capacity and ability to translocate systemically. Studies examining associations between prenatal UFP exposure and childhood asthma remain sparse. Objectives: We used daily UFP exposure estimates to identify windows of susceptibility of prenatal UFP exposure related to asthma in children, accounting for sex-specific effects. Methods: Analyses included 376 mother-child dyads followed since pregnancy. Daily UFP exposure during pregnancy was estimated by using a spatiotemporally resolved particle number concentration prediction model. Bayesian distributed lag interaction models were used to identify windows of susceptibility for UFP exposure and examine whether effect estimates varied by sex. Incident asthma was determined at the first report of asthma (3.6 ± 3.2 yr). Covariates included maternal age, education, race, and obesity; child sex; nitrogen dioxide (NO2) and temperature averaged over gestation; and postnatal UFP exposure. Measurements and Main Results: Women were 37.8% Black and 43.9% Hispanic, with 52.9% reporting having an education at the high school level or lower; 18.4% of children developed asthma. The cumulative odds ratio (95% confidence interval) for incident asthma per doubling of the UFP exposure concentration across pregnancy was 4.28 (1.41-15.7), impacting males and females similarly. Bayesian distributed lag interaction models indicated sex differences in the windows of susceptibility, with the highest risk of asthma seen in females exposed to higher UFP concentrations during late pregnancy. Conclusions: Prenatal UFP exposure was associated with asthma development in children, independent of correlated ambient NO2 and temperature. Findings will benefit future research and policy-makers who are considering appropriate regulations to reduce the adverse effects of UFPs on child respiratory health.

Identifying Toxicologically Significant Compounds in Urban Wildfire Ash Using In Vitro Bioassays and High-Resolution Mass Spectrometry

Urban wildfires may generate numerous unidentified chemicals of toxicity concern. Ash samples were collected from burned residences and from an undeveloped upwind reference site, following the Tubbs fire in Sonoma County, California. The solvent extracts of ash samples were analyzed using GC- and LC-high-resolution mass spectrometry (HRMS) and using a suite of in vitro bioassays for their bioactivity toward nuclear receptors [aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and androgen receptor (AR)], their influence on the expression of genetic markers of stress and inflammation [interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2)], and xenobiotic metabolism [cytochrome P4501A1 (CYP1A1)]. Genetic markers (CYP1A1, IL-8, and COX-2) and AhR activity were significantly higher with wildfire samples than in solvent controls, whereas AR and ER activities generally were unaffected or reduced. The bioassay responses of samples from residential areas were not significantly different from the samples from the reference site despite differing chemical compositions. Suspect and nontarget screening was conducted to identify the chemicals responsible for elevated bioactivity using the multiple streams of HRMS data and open-source data analysis workflows. For the bioassay endpoint with the largest available database of pure compound results (AhR), nontarget features statistically related to whole sample bioassay response using Spearman's rank-order correlation coefficients or elastic net regression were significantly more likely (by 10 and 15 times, respectively) to be known AhR agonists than the overall population of compounds tentatively identified by nontarget analysis. The findings suggest that a combination of nontarget analysis, in vitro bioassays, and statistical analysis can identify bioactive compounds in complex mixtures.

Variations in Reactive Oxygen Species Generation by Urban Airborne Particulate Matter in Lung Epithelial Cells-Impact of Inorganic Fraction

Air pollution is associated with numerous negative effects on human health. The toxicity of organic components of air pollution is well-recognized, while the impact of their inorganic counterparts in the overall toxicity is still a matter of various discussions. The influence of airborne particulate matter (PM) and their inorganic components on biological function of human alveolar-like epithelial cells (A549) was investigated in vitro. A novel treatment protocol based on covering culture plates with PM allowed increasing the studied pollutant concentrations and prolonging their incubation time without cell exposure on physical suffocation and mechanical disturbance. PM decreased the viability of A549 cells and disrupted their mitochondrial membrane potential and calcium homeostasis. For the first time, the difference in the reactive oxygen species (ROS) profiles generated by organic and inorganic counterparts of PM was shown. Singlet oxygen generation was observed only after treatment of cells with inorganic fraction of PM, while hydrogen peroxide, hydroxyl radical, and superoxide anion radical were induced after exposure of A549 cells to both PM and their inorganic fraction.

Chronic real-time particulate matter exposure causes rat pulmonary arteriole hyperresponsiveness and remodeling: The role of ETBR-ERK1/2 signaling

Exposure to air pollution is associated with the incidence of respiratory diseases. The present study evaluated the pulmonary vascular system injury by chronic real-time particulate matter (PM₁₀) exposure and investigated the underlying mechanisms. Rats were exposed to PM₁₀ or filtered air for 2 to 4 months using a whole body exposure system, and intraperitoneally injected with the MEK1/2 inhibitor U0126. Right heart catheterization and myography were performed to detect lung function and pulmonary vascular reactivity, respectively. Western blotting, qRT-PCR, enzyme-linked immunosorbent assay and histological analyses were used to detect the effects and mechanisms by which PM₁₀ exposure-induced pulmonary vascular dysfunction. Functional experiment results showed that PM₁₀ exposure increased the pulmonary artery pressure of rats and caused endothelin B receptor (ET_BR)-mediated pulmonary arteriole hyperreactivity. U0126 significantly rescued these pathological changes. PM₁₀ exposure upregulated the contractile ET_BR of pulmonary arteriolar smooth muscle, and damaged pulmonary artery endothelial cells to induce the release of more endothelin 1 (ET-1). The upregulated ET_BR bound to increased ET-1 induced pulmonary arteriolar hyperresponsiveness and remodeling. U0126 inhibited the PM₁₀ exposure-induced upregulation of ET_BR in pulmonary arteriole, ET_BR-mediated pulmonary arterial hyperresponsiveness and vascular remodeling. In conclusion, chronic real-time particulate matter exposure can activate the ERK1/2 signaling, thereby inducing the upregulation of contractile ET_BR in pulmonary arteriole, which may be involved in pulmonary arteriole hyperresponsiveness and remodeling in rats. These findings provide new mechanistic evidence of PM₁₀ exposure-induced respiratory diseases, and a new possible target for treatment.