The antonym for the phrase "more unpolluted" would be "more polluted." Pollution is a widespread issue that affects many societies around the world. While more unpolluted environments refer to a place with less contamination by pollutants, a more polluted environment indicates an increase in hazardous substances such as air, water, and soil pollution. Ecosystems, plants, and animals face serious consequences due to pollution, threatening biodiversity and sustainability. Hence, it is crucial to raise awareness and take action to reduce pollution levels and improve the quality of the environment. A more sustainable and cleaner environment is essential for the well-being of humans and the planet.