Influenced by this urgency, researchers quantified the environmental impact of water fluoridation for a single five-year-old child over a one-year period.

They compared it to the traditional usage of fluoride varnish and toothbrushing programmes, both in the UK and abroad.

Today, more than 35 per cent of the world's population has access to fluoridated water, and studies demonstrate considerable decreases in tooth cavities.

While statistics on the clinical effectiveness and cost-benefit analyses of water fluoridation are available, there is currently no evidence of its environmental impact.

To assess this impact, the research team conducted a Life Cycle Assessment (LCA) by meticulously calculating the combined travel, weight and quantities of all items and activities involved in all three preventative programmes (toothbrushing, fluoride varnish programmes, and water fluoridation).

Data were entered into a specific environmental application (OpenLCA), and the team used the Ecoinvent database to determine environmental outputs such as carbon footprint, the quantity of water required for each product, and land use.

According to the study's findings, which were led by Brett Duane, associate professor in Dental Public Health at Trinity College, water fluoridation had the lowest environmental impact in all categories studied and the lowest disability-adjusted life years impact when compared to all other community-level caries prevention programmes.

The study also discovered that water fluoridation provides the best return on investment.

Researchers feel that water fluoridation should be the preventative intervention of choice due to the balance of clinical effectiveness, financial effectiveness, and environmental sustainability.

This study adds to the international case for water fluoridation programmes to minimise dental decay, particularly among the most vulnerable people.

Duane stated, "As the climate problem worsens, we must find strategies to avoid disease in order to lessen the environmental impact of our health-care systems. This study clearly shows that water fluoridation has a low carbon footprint as an effective preventative technique."

Professor Paul Ashley, senior clinical lecturer (Honorary NHS Consultant) at the University College London Eastman Dental Institute, added, "There should be renewed efforts to promote access to this intervention."