Children’s exposure to UV

Researchers like Richard McKenzie have shown that summer radiation in New Zealand has the potential to burn and, as research shows that excess UV exposure in early life could be an important risk factor for skin cancer (particularly melanoma), the Cancer Society decided to fund some research to find out about New Zealand children’s exposure to UV radiation from the Sun.

In the summer of 2004–2005, 491 school children (year 4 and year 8 students from 27 schools throughout New Zealand) took part in a study where physicists from NIWA and social scientists from the University of Otago measured each child’s personal exposure to UV as well as their activity during the day and how they were protected from UV. This was a massive undertaking, and Gregory Bodeker (from Lauder) and Caradee Wright and Anthony Reeder (from the University of Otago) developed this scientific experiment to provide a database that was the first of its kind in the world.

The children wore electronic UV monitors (dosimeters) that had been developed by Martin Allen from the University of Canterbury.

These dosimeters logged each child’s UV exposure at eight-second intervals throughout the day. Each child was also asked to keep an activity diary for the seven days they wore the dosimeter, where they recorded what they were doing, where they were, what clothes they were wearing and whether they were using any sun protection. The researchers also used a questionnaire to record the children’s knowledge about and attitudes to sun safety. The research project was very thorough because these scientists also monitored the UV radiation at the children’s schools, gathered school policies on sun protection of their students and kept a record of each child’s skin type.

The research team compiled all this data in an extensive database and were able to create graphs that displayed each child’s activities and UV exposure during the seven days.

Once the data was analysed, it showed each child’s personal exposure rates related to their activities and time of the day these activities happened.

The results surprised the scientists. They found that the average daily personal UV exposure was relatively low, but some children did experience enough UV exposure to be sunburnt. Boys experienced a higher exposure rate than girls, and year 8 students experienced higher UV exposure than year 4 students.

What was most surprising was that, even though the average total exposure of UV was relatively low, the personal exposure rates were higher on school days than during the weekend. The scientists felt that it could be important to ensure that children don’t get too much UV exposure during the daylight-saving months.

The Cancer Society and the scientists predict that this database will be an important source of information for developing health promotion programmes and will be useful for future studies of the distribution of skin cancers in New Zealand.