Published Paper Details:

Air pollution has emerged as one of the most significant environmental and public health challenges worldwide, particularly in urban and industrial regions. The increasing concentration of harmful gases and pollutants in the atmosphere due to industrial activities, vehicle emissions, and rapid urbanization has led to severe health issues, including respiratory diseases, cardiovascular disorders, and reduced quality of life. Continuous monitoring of air quality is therefore essential to ensure environmental sustainability and public health protection. However, conventional air quality monitoring systems are often expensive, fixed in location, and inaccessible for personal use. This paper presents **BreathX: A Personal Air Quality Checker using Internet of Things (IoT)**, a smart, portable, and cost-effective solution for real-time environmental monitoring. The proposed system is built using the **NodeMCU ESP8266** microcontroller, which provides wireless connectivity and efficient data processing capabilities. The system integrates an **MQ135 gas sensor** to detect harmful air pollutants and a **DHT11 sensor** to measure temperature and humidity levels. The collected environmental data is continuously processed and transmitted to the **ThingSpeak cloud platform**, enabling remote monitoring, data storage, and graphical analysis of air quality parameters. To enhance user awareness and safety, the system incorporates an **OLED display** for local real-time visualization of environmental conditions and an **SG90 servo motor-based alert mechanism** that activates whenever pollutant levels exceed predefined safety thresholds. This feature allows users to receive immediate notifications regarding deteriorating air quality conditions. Experimental results demonstrate that the proposed system effectively monitors environmental parameters and provides reliable real-time air quality information with cloud connectivity. The developed solution offers advantages such as low implementation cost, portability, energy efficiency, and ease of deployment in homes, educational institutions, healthcare facilities, and workplaces. Furthermore, the system contributes to personalized environmental awareness and preventive healthcare by enabling users to make informed decisions based on surrounding air quality conditions. Future enhancements may include the integration of PM2.5 and PM10 particulate matter sensors, GPS-based pollution mapping, mobile application support, and machine learning algorithms for predictive air quality analysis. The proposed BreathX system represents an efficient and scalable approach toward smart environmental monitoring and healthier living environments.