A study examined two buildings in Sydney, Australia – one with a green roof and one without. They tested the green roof's ability to reduce metal pollution in stormwater and manage runoff. Results showed the green roof effectively trapped copper, zinc, and chromium, reducing their harmful effects. Computer models predicted the green roof could decrease stormwater flow by about half during less frequent heavy storms and up to 90% in lighter ones. This means green roofs can help clean up the environment by keeping pollutants out of waterways, while also cooling the surrounding area. Future research could explore how different plants and soil types impact green roofs' pollution-cleaning abilities further.