# Influence of Particulate Matter and Carbon Dioxide on Students' Emotions in a Smart Classroom
## 1 Introduction
### Effects on Emotions and Mental Health  
The emotional impact of air pollutants such as CO\({}_{2}\) and PM has been less documented, with varying effects depending on the type of pollutant and environmental conditions. Exposure to high levels of CO\({}_{2}\) has been shown to trigger emotional responses resembling panic attacks. According to [24], inhaling elevated levels of CO\({}_{2}\) can replicate the fear and discomfort typical of spontaneous panic episodes. This suggests that poor IAQ,particularly in enclosed spaces like classrooms, can have profound emotional consequences for occupants. In terms of PM, research has demonstrated that PM\({}_{2.5}\) is particularly harmful to emotional well-being. Ref. [25] observed that in Beijing, negative emotional responses increased when PM\({}_{2.5}\) levels reached approximately 150 AQI, a level classified as \"unhealthy\". Furthermore, different social groups exhibited varying sensitivities to emotional well-being, with more pronounced negative emotions occurring when AQI levels surpassed 200, classified as \"very unhealthy\". Similarly, Ref. [26] found a significant link between elevated PM\({}_{2.5}\) levels and emotional intensity, as evidenced by an increase in negative social media posts during periods of high pollution. These findings underscore how poor air quality can heighten negative emotions in urban environments, particularly under severe pollution conditions. Regarding PM\({}_{10}\), Ref. [27] noted that during the winter, higher levels of PM\({}_{10}\) contributed to a rise in negative public sentiment, reflected in media coverage. This research highlights how air pollution can shape not only individual emotions but also collective public perception, with pollution reduction efforts leading to more positive emotions and public perceptions. General air pollution, encompassing a range of contaminants like PM and nitrogen dioxide (NO\({}_{2}\)), has also been linked to significant emotional and mental health impacts. Ref. [28] revealed a strong association between short-term exposure to urban air pollutants and an increase in emergency visits for mental health issues among youth aged 8 to 24. This suggests that younger populations are particularly vulnerable to the emotional and psychological consequences of air pollution. One study [29] introduced the concept of Affective Sensitivity to Air Pollution (ASAP), which measures emotional fluctuations in response to daily changes in air pollution. Individuals with higher ASAP experience more pronounced emotional changes when pollution levels shift. This construct emphasizes the variability in how individuals emotionally react to pollution, suggesting that sensitivity to air quality can significantly affect emotional well-being. Emotional states themselves can also modulate the effects of air pollution. Ref. [30] demonstrated that individuals with lower emotional well-being, such as those experiencing unhappiness, are more vulnerable to the negative effects of air pollution on physical health, particularly in lung function and blood pressure. In contrast, happier individuals showed less pronounced adverse effects, highlighting the interplay between emotional health and environmental stressors. Finally, classroom environmental conditions play a crucial role in shaping students' emotional engagement and overall well-being. Ref. [31] found that temperature, air enthalpy, and humidity significantly affected students' vigor and dedication to their studies. Higher temperatures were linked to reduced energy and concentration, while increased air enthalpy and humidity were positively associated with dedication and vigor. Additionally, elevated levels of total volatile organic compounds (TVOCs) were associated with diminished dedication, suggesting that poor IAQ can impair emotional and cognitive engagement in educational settings.