## 1 Introduction
The spatial change of atmospheric self-purification capacity in the Chengdu Plain Economic Zone of Sichuan Province shows an overall trend of low in the southwest and high in the northeast ([PERSON] and [PERSON], 2021) [16]. In addition to natural factors, human factors affect the impact of atmospheric self-purification capacity on environmental pollution. [PERSON] et al. (2017) reveal that urbanization is one of main reasons for the worsening air quality in Zhejiang Province. The deepening of urbanization increases the underlying surface roughness. This, in turn, reduces ground wind speed and weakens atmospheric self-purification capacity [17]. [PERSON] et al. (2019) discover that the urban scale of the Beijing-Tianjin-Hebei region and its neighboring regions forms a reverse relationship with ground wind speed. Therefore, the rapid increase in heavily polluted meteorological conditions is also affected by urbanization to some extent [1]. As the core means for national agencies to control environmental pollution, environmental regulation helps to consolidate the path of regional green development and offset the lack of market governance ([PERSON] and [PERSON], 2020) [18]. Chinese and foreign scholars attain remarkable achievements in the research on the relationship between environmental regulation and environmental pollution. In terms of how to promote the effect of environmental regulation on emission reduction, relevant research mainly centers on the dominant role of the reversed emission reduction effect or the compliance cost effect in environmental regulation ([PERSON] and [PERSON], 2022) [19]. Scholars who support the former view believe that strengthening environmental regulation can curb environmental pollution in various regions. There are two reasons. On the one hand, governments compel enterprises to conduct necessary pollution pre-treatment and reduce waste emissions by taking regulatory policies such as raising the threshold for the entry of polluting industries and levying high environmental pollution taxes ([PERSON] et al., 2022) [20]. On the other hand, long-term environmental regulation encourages enterprises to engage in more innovative activities, improve their production efficiency and competitiveness, and forge the innovation compensation effect to offset the compliance cost of environmental regulation. This spurs corporate technological innovation ([PERSON], 2019) [21] and has a positive impact on the prevention and control of environmental pollution. Simultaneously, environmental regulation increases the production cost of some pollution-intensive industries. The drop in industrial profits squeezes out some enterprises with the inappropriate allocation of production factors and low efficiency, helping to achieve independent adjustment, optimization, and upgrading of industrial structure ([PERSON] et al., 2022) [22]. Scholarswho are in favor of the latter view affirm that environmental regulation internalizes the external environmental costs of enterprises in the short term. As the corporate cost or expenditure increases, it constrains the capital for technological innovation and impedes the enterprise's technological innovation. [PERSON] and [PERSON] (2022) conclude that the implementation of environmental regulation counts against the transformation of new and old kinetic energies ([PERSON] and [PERSON], 2022). In brief, the existing literature makes great contributions to the research in this regard yet fails to discuss three topics satisfactorily. Hopefully, this paper can further the research. First, the research findings on atmospheric self-purification capacity prove inadequate. Scholars commonly acknowledge that raising atmospheric self-purification capacity has a positive effect on improving air quality, which lays a solid foundation for this paper. Nevertheless, under what conditions can atmospheric self-purification capacity play a better role in controlling environmental pollution, and what factors affect the role?