Vehicular pollution significantly contributes to environmental degradation and poses serious health risks. Traditional emission monitoring relies on periodic checks at fixed stations, which provide limited and delayed feedback, lacking real time insights. This paper proposes a portable Internet of Things (IoT)-based Vehicular Pollution Detection System that monitors real-time emission levels using gas sensors—MQ-7 (CO), MQ-135 (CO₂, NOₓ), and MQ-2 (HC). A SIM808 module is used to combine GSM and GPS, to transmit data to the ThingSpeak cloud, to enable geo-referenced monitoring and identify high-emission zones. Real time alerts are sent to vehicle owners and authorities when pollutant levels exceed threshold limits. The portable prototype is implemented using Arduino Uno WiFi, for accurate pollution tracking and alerts. Continuous pollution tracking, real-time alerts and cloud-based analysis support proactive environmental management, enhance urban air quality monitoring and contribute to sustainable public health practices.