Up to 95% of melanoma and 99% of non-melanoma skin cancers are a result of over exposure to UV radiation. Despite being largely preventable, skin cancer remains a global problem, with an estimated 1.5 million people diagnosed in 2020 worldwide. During the same period, more than 120 000 people across the world lost their lives to this highly preventable disease. The SunSmart Global UV app seeks to bring worldwide consistency to UV reporting and public health messaging, and to tackle the worldwide burden of skin cancer and UV-related eye damage. It does this by bringing sun protection advice to anyone with the app on their mobile phone based on their selected location.

While great gains have been made in relation to the implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer that has reduced the impact of UV on human health, it is still vitally important for the public to garner a better understanding of the dangers of prolonged UV radiation exposure. Evidence shows that personal habits in relation to ongoing sun exposure, including sunscreen use, clothing choice and time spent outdoors, are the most important individual risk factors for UV-related skin and eye damage. Developed in Australia by the Cancer Council Victoria, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) and the Bureau of Meteorology, the SunSmart Global UV app was launched in July 2022 with the support of WHO, WMO, the United Nations Environment Programme (UNEP) and the International Labour Organization (ILO). The SunSmart Global UV app was designed primarily to influence sun protection behaviour by providing individual users with the times of the day when sun protection is required, no matter what their location. The SunSmart Global UV app utilizes forecast UV data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and weather information from the Hong Kong Observatory. The app also has the capacity to draw on live UV data when available. In Australia for example, the app collects live UV data from monitoring stations across the country. The live UV data is updated every 1–2 minutes and is available for anyone who is within a 100 km radius from a fixed UV monitoring site.

The SunSmart Global UV app utilizes global UV forecast data sources and converts that information to provide clear public health advice in a way that is designed to motivate sun protective behaviour. The app includes four-day UV forecast of sun protection times and weather information, and is available in eight languages including English, French, Spanish, Dutch, Chinese, German, Italian and Russian. Since its launch in June 2022, the app has been downloaded over 150 000 times. The SunSmart Global UV app is available free of charge at both App Store and Google Play.

Launching an app globally with the support of United Nations agencies requires a lot of work, time and tenacity – but is worth it. A key limitation has been containing costs. To build an app to suit a global audience across multiple languages requires a good budget, not just to cover the app build, but also the ongoing maintenance and promotion costs.

With the support of world-leading health and meteorological organizations, combined with the benefits of technology to deliver locationspecific health advice, we hope to decrease the significant global burden of skin cancer and eye disease.