Around 13,000 schoolchildren across Hertfordshire will soon be breathing cleaner air as the county council begins the third phase of its classroom air-purifier project this month.

From 10 November, Hertfordshire County Council has started to install one low-wattage air-purifying unit in every classroom of selected schools, with priority given to those in areas of higher deprivation, higher outdoor pollution levels and all special schools.

The latest rollout means more than 30,000 children will have benefited from cleaner classroom air since the project began.

Funded through the Sustainable Hertfordshire Central Fund, the system is free for schools, aside from the small cost of electricity needed to run each unit. Earlier phases of the scheme saw particulate pollution inside classrooms fall by around 30% – with even bigger reductions recorded on high-pollution days.

Cllr Adrian England, Executive Member for Sustainability, said the programme is already making a noticeable difference. "We know that air quality can have a real impact on children's health and wellbeing. By investing in these purifiers, we're helping to ensure that pupils can focus on their learning in a cleaner, healthier environment. This project is another example of how Hertfordshire is leading the way in improving the health of our communities and protecting future generations."

Teachers and school staff will be supported to share stories, photos and videos of the units in action to help shape the council's future sustainability projects.

The initiative forms part of Hertfordshire County Council's wider ambition to build a "cleaner, greener and more sustainable county" for the years ahead.