WHO estimates that around 7 million people die every year from exposure to fine particles that lead to diseases such as lung cancer. In South America, for instance, every year 2.5 million people die due to high levels of PM2.5 (WHO, 2021) and less than 8.5% of the urbanised cities in the region are monitoring air quality (IQ Air, 2021). This air quality challenge results in economic costs, which are estimated to be around 6.1% of each country’s GDP (World Band, 2022). Purify City aims to address this public health issue with the power of AI and data science. We collect data using sensors that capture different pollutants such as PM1, PM2.5, and CO2. We use these sensors to create an IoT network and generate accurate data 10 times more frequently than conventional sensors available in South America. This high-quality data let us to bring insights into policy making and know air quality in real time.