## 2 Literature Review
### The Necessity and Effectiveness of Installing Particulate Matter Monitors  
PM monitors play a crucial role in public health by providing real-time information on air quality, particularly on the levels of PM such as PM10 and PM2.5 [28]. These monitors raise awareness and enable prompt responses to high PM levels, allowing individuals and communities to make informed decisions about outdoor activities and protective measures. PM monitors also serve as important resources for researchers and policymakers, providing data to study pollution patterns, assess the effectiveness of air quality regulations, and develop strategies to reduce exposure to harmful particulates [18; 29].  
Installing PM monitors is particularly necessary in areas with high concentrations of vulnerable populations, such as older adults, children, and those with pre-existing health conditions [28]. These groups are more susceptible to health issues related to PM, including respiratory and cardiovascular diseases. Strategically placing PM monitors near hospitals, schools, and senior centers, communities ensures that at-risk individuals receive timely information regarding air quality. Moreover, certain regions may have varying levels of air pollution due to local sources of PM such as traffic, industrial activities, or construction sites. Installing monitors in these areas allows the identification of pollution hotspots and the assessment of localized air quality issues [30]. These data are critical for implementing targeted interventions to improve air quality and protect public health.  
The primary benefit of PM monitors is their ability to provide real-time air quality information, which is essential for protecting public health [31]. When PM levels rise, timely alerts can prompt individuals to take protective measures such as staying indoors, using air purifiers, or wearing masks. Immediate access to air quality data empowers people to make informed decisions and reduce their exposure to harmful particulates. For policymakers and urban planners, the data collected by PM monitors are invaluable for shaping air quality management strategies [32]. By analyzing trends and patterns in PM concentrations, authorities can identify sources of pollution and implement regulations or interventions to address them. This data-driven approach ensures that resources are allocated effectively and that air quality improvement efforts are based on solid evidence. Furthermore, PM monitors can enhance community engagement and awareness of air pollution issues [33]. By making air quality data accessible to the public through websites, mobile apps, or public displays, communities can foster a greater understanding of environmental health risks and encourage proactive behaviors to mitigate exposure. Increased awareness can drive collective action and support policies aimed at reducing air pollution. In addition to health benefits, PM monitors can contribute to broader environmental and economic gains. Improved air quality reduces healthcare costs associated with treating pollution-related illnesses. It also enhances the overall quality of life, making cities more attractive places to live, work, and visit. Consequently, investments in air quality monitoring can yield significant long-term returns for both public health and economic development.