Design of a Low-Power Air Quality Monitoring System for Urban Areas in Kano, North West Nigeria

This project designs and deploys a low-power air quality monitoring system for real-time measurement of particulate matter and gaseous pollutant concentrations in urban areas of Kano City, North West Nigeria. Kano's rapid industrialisation and high vehicle density have elevated air pollution to a public health concern, yet continuous monitoring infrastructure is absent across most of the city. The monitoring unit integrates a PMS5003 laser particle counter for PM2.5 and PM10 measurement, an MQ-135 gas sensor array for detection of carbon dioxide, ammonia, and benzene, a DHT22 temperature and humidity sensor, and an ESP8266 Wi-Fi module for data transmission. An ATmega328P microcontroller manages sensor polling, data aggregation, and transmission scheduling. The system is powered by a 6W solar panel with a 3.3Ah lithium polymer battery, enabling continuous outdoor operation without mains power. Sensor data are transmitted to a ThingSpeak cloud platform every five minutes, where they are displayed on a public dashboard accessible to environmental health authorities. Five monitoring units were deployed at representative urban sites including a main road junction, an open-air market, a residential neighbourhood, an industrial estate boundary, and a school compound. Three-week monitoring results show PM2.5 concentrations at the industrial site exceeding the WHO 24-hour guideline of 15 micrograms per cubic metre on 78 percent of monitoring days. The school compound recorded elevated PM10 during peak morning traffic hours. Recommendations include expanding the network to 20 sites for comprehensive urban coverage. Keywords: air quality monitoring, particulate matter, IoT sensor, urban pollution, Kano.