The Temporal and Spatial Distribution Characteristics of Air Pollution Index and Meteorological Elements in Beijing, Tianjin, and Shijiazhuang, China

A dynamic game modeling on air pollution mitigation with regional cooperation and noncooperation

Mitigating regional air pollution involves multifaceted trade-offs, including long-term versus short-term development versus emission-reduction among different regions. Considering the heterogeneity of levels of regional economic development and capacity for environmental governance as well as the spatial spillover effect of pollution, the game theory method can explore each region's dynamic emission-reduction path. In this article, the dynamic game mechanism (Regional Environment Economy Game Modeling model) is incorporated into the environment economy system to solve the Nash equilibrium under dynamic conditions and explore the game strategies of each region. Taking air pollution mitigation in North China as an example, this article compares the emission-reduction effect and social welfare under regional cooperative and noncooperative game scenarios and clarifies the abatement-sharing mechanism between provinces. The results show that a noncooperative policy is strictly inferior to a cooperative policy for achieving given emission-reduction goals and maximizing social welfare. Our findings offer evidence for strengthening regional cooperation in reducing carbon emissions and provide policy recommendations for synergistic pollution abatement and joint regional pollution mitigation. Integr Environ Assess Manag 2023;19:1555-1569. © 2023 SETAC.

Interaction of air pollution and meteorological factors on IVF outcomes: A multicenter study in China

BACKGROUND

Previous studies revealed associations between air-pollutant exposure and in vitro fertilization (IVF) outcomes. However, modification effects of air pollution on IVF outcomes by meteorological conditions remain elusive.

METHODS

This multicenter retrospective cohort study included 15,217 women from five northern Chinese cities during 2015-2020. Daily average concentrations of air pollutants (PM_2.5, PM₁₀, O₃, NO₂, SO₂, and CO) and meteorological factors (temperature, relative humidity, wind speed, and sunshine duration) during different exposure windows were calculated as individual approximate exposure. Generalized estimating equations models and stratified analyses were conducted to assess the associations of air pollution and meteorological conditions with IVF outcomes and estimate potential interactions.

RESULTS

Positive associations of wind speed and sunshine duration with pregnancy outcomes were detected. In addition, we observed that embryo transfer in spring and summer had a higher likelihood to achieve a live birth compared with winter. Exposure to PM_2.5, SO₂, and O₃ was adversely correlated with pregnancy outcomes in fresh IVF cycles, and the associations were modified by air temperature, relative humidity, and wind speed. The inverse associations of PM_2.5 and SO₂ exposure with biochemical pregnancy were stronger at lower temperatures and humidity. Negative associations of PM_2.5 with clinical pregnancy were only significant at lower temperatures and wind speeds. Moreover, the effects of O₃ on live birth were enhanced by higher wind speed.

CONCLUSIONS

Our results suggested that the associations between air-pollutant exposure and IVF outcomes were modified by meteorological conditions, especially temperature and wind speed. Women undergoing IVF treatment should be advised to reduce outdoor time when the air quality was poor, particularly at lower temperatures.

The effect of real-ambient PM2.5 exposure on the lung and gut microbiomes and the regulation of Nrf2

The influence of air pollution on human health has sparked widespread concerns across the world. Previously, we found that exposure to ambient fine particulate matter (PM2.5) in our "real-ambient exposure" system can result in reduced lung function. However, the mechanism of organ-specific toxicity is still not fully elucidated. The balance of the microbiome contributes to maintaining lung and gut health, but the changes in the microbiome under PM2.5 exposure are not fully understood. Recently, crosstalk between nuclear factor E2-related factor 2 (Nrf2) and the microbiome was reported. However, it is unclear whether Nrf2 affects the lung and gut microbiomes under PM2.5 exposure. In this study, wild-type (WT) and Nrf2^-/- (KO) mice were exposed to filtered air (FA) and real ambient PM2.5 (PM) in the " real-ambient exposure" system to examine changes in the lung and gut microbiomes. Here, our data suggested microbiome dysbiosis in lung and gut of KO mice under PM2.5 exposure, and Nrf2 ameliorated the microbiome disorder. Our study demonstrated the detrimental impacts of PM2.5 on the lung and gut microbiome by inhaled exposure to air pollution and supported the protective role of Nrf2 in maintaining microbiome homeostasis under PM2.5 exposure.

Aircraft-based observation of gaseous pollutants in the lower troposphere over the Beijing-Tianjin-Hebei region

To investigate the spatial and vertical distribution of atmospheric pollutants (SO₂, NO_x, CO and O₃), aircraft-based measurements (model: Yun-12, 12 flights, 27 h total flight time) were conducted from near the surface up to 2400 m over the Beijing-Tianjin-Hebei (BTH) region between June 17th and July 22nd 2016. The results showed that high concentrations of primary gaseous pollutants (SO₂, NO_x, CO) were generally present in Beijing, Tianjin, Langfang and Tangshan areas, while high values of O₃ frequently appeared in areas far from the city. The flights at noon and dusk measured higher O₃ concentrations at 600 m and lower O₃ concentrations at higher altitudes, implying a strong influence by photochemical production. Back trajectory analysis suggested that the high levels of gaseous pollutants, especially at 600 m, were associated with pollution sources transported from the southerly direction during the observation period. The first simultaneous vertical distribution measurements using aircraft and tethered balloon were conducted in Gaocun (a rural site between Beijing and Tianjin) on June 17th. The results indicated that an inversion layer at the top of the planetary boundary layer (PBL) significantly suppressed vertical exchange through the PBL and resulted in a "two-layer" vertical distribution of pollutants above and below the PBL. Additionally, a residual high O₃ layer (79.9 ± 2.5 ppb, 500-1000 m) was observed above the PBL, and it contributed to the surface peak O₃ level at noon through downward transport along with the opening up of the PBL. These results indicate that coupled effects of horizontal and vertical transport should be investigated in future studies to improve the chemical transport models used to study the vertical distribution and regional transport over the BTH region.

Spatio-temporal distribution of six pollutants and potential sources in the Hexi Corridor, Northwest China

Particulate matter (PM) concentrations are affected by anthropogenic emissions and sand transport jointly; however, the relative contributions from those two aspects are usually unknown. In our work, statistical analysis and back trajectories model were used to identify the dominant source in such area, by taking Yumen City as an example. We come to the conclusion that local emissions dominate the concentration of airborne pollutants, while sand transport plays a significant role on PM concentration. The conclusions were supported by the following results. (1) PM monthly mean concentrations at the two air quality stations, which are 70 km far away from each other, have the similar levels and variation trend; furthermore, a regression analysis of PM_2.5 and PM₁₀ daily concentrations between both stations indicated a significant correlation, suggesting that PM at both locations was influenced by the same emission sources; (2) statistical analysis results revealed that PM concentration has a positive correlation with wind speed, indicating the wind-blown dust and sand contribute mainly on PM concentration; (3) back-trajectory clustering analysis indicates that long-distance transport particulates from dust sources and their pathways had a significant impact on local PM concentrations.