This article presents an IoT-based system for air pollution monitoring with secure data transmission. The system is designed to monitor and publish real-time air quality information, addressing both indoor and outdoor air pollution. The system uses micro-sensors to collect data on air quality parameters such as CO₂, CO, PM₁₀, NO₂, temperature, and humidity. Data are collected using sensors mounted on electric vehicles and transmitted to a central server. Users can subscribe to the system and receive information about local pollution levels. The system also includes a secure data transmission protocol to ensure system security and resistance to attacks. The system consists of four layers: data collection, end devices, central server, and communication. Autonomous vehicles (AVs) collect air quality data and transmit it to the central server. The central server processes the data, generates statistics, and publishes them to users. The communication layer uses the MQTT protocol for secure data transmission between AVs and devices, and the Amelia protocol for secure communication between AVs and the central server. The Amelia protocol is modified to ensure secure authentication and data transmission between AVs and the central server. The system uses a Nissan Leaf electric vehicle for data collection and a specialized measuring instrument with sensors for PM₁₀, PM₂.₅, CO, NO₂, NO, SO₂, temperature, humidity, and pressure. The data collected are used to assess air quality and its impact on human health. The system also includes a secure data transmission protocol to protect against attacks and ensure data integrity. The system's results show that atmospheric pressure can influence the concentration of suspended particles, although the relationship is indirect and related to weather conditions. The system provides real-time air quality data, which can be visualized using heat maps or numerical values. The data are available to subscribers, enabling informed decisions about outdoor activities and health precautions. The system's secure data transmission protocol ensures the confidentiality and integrity of the data, making it a reliable solution for air pollution monitoring.This article presents an IoT-based system for air pollution monitoring with secure data transmission. The system is designed to monitor and publish real-time air quality information, addressing both indoor and outdoor air pollution. The system uses micro-sensors to collect data on air quality parameters such as CO₂, CO, PM₁₀, NO₂, temperature, and humidity. Data are collected using sensors mounted on electric vehicles and transmitted to a central server. Users can subscribe to the system and receive information about local pollution levels. The system also includes a secure data transmission protocol to ensure system security and resistance to attacks. The system consists of four layers: data collection, end devices, central server, and communication. Autonomous vehicles (AVs) collect air quality data and transmit it to the central server. The central server processes the data, generates statistics, and publishes them to users. The communication layer uses the MQTT protocol for secure data transmission between AVs and devices, and the Amelia protocol for secure communication between AVs and the central server. The Amelia protocol is modified to ensure secure authentication and data transmission between AVs and the central server. The system uses a Nissan Leaf electric vehicle for data collection and a specialized measuring instrument with sensors for PM₁₀, PM₂.₅, CO, NO₂, NO, SO₂, temperature, humidity, and pressure. The data collected are used to assess air quality and its impact on human health. The system also includes a secure data transmission protocol to protect against attacks and ensure data integrity. The system's results show that atmospheric pressure can influence the concentration of suspended particles, although the relationship is indirect and related to weather conditions. The system provides real-time air quality data, which can be visualized using heat maps or numerical values. The data are available to subscribers, enabling informed decisions about outdoor activities and health precautions. The system's secure data transmission protocol ensures the confidentiality and integrity of the data, making it a reliable solution for air pollution monitoring.