Monitoring Air Quality Using Low-Cost Internet of Things

الملخص

Air pollution poses a severe threat to public health and the environment, particularly in crisis-affected 
regions like Aleppo, Syria. The Heavy reliance on diesel generators due to frequent power outages, compounded by 
the aftermath of conflict, has led to dangerously high levels of airborne pollutants. There is an urgent need for 
accessible and reliable air quality monitoring to identify pollution sources and assess risks. This study presents an 
innovative, low-cost air quality monitoring system based on the Internet of Things (IoT) technology. The system 
utilizes MQ-7 (CO), MQ-135 (CO₂ ), and DHT22 (temperature and humidity) sensors connected to an Arduino 
Uno microcontroller. Real-time data are transmitted and visualized via the Blynk Console cloud platform, enabling 
remote monitoring and analysis. Field conducted in Aleppo across four locations (university campus, traffic 
intersection, diesel generator and residential area) during autumn and winter revealed critical findings. Pollution 
levels were significantly higher near traffic intersections and generators. Carbon monoxide (CO) concentrations 
near generators reached up to 11.23 ppm, and carbon dioxide (CO₂ ) levels peaked at 1877.6 ppm—both 
substantially exceeding World Health Organization (WHO) safety guidelines (4.0 ppm for CO over 8 hours, and 
1000 ppm threshold for CO₂ ). The study demonstrates the system's effectiveness in providing transparent, reliable, 
and accessible environmental data, highlighting its potential for deployment in resource-limited and crisis-affected 
environments to support informed decision-making and public awareness.