Children should have their say in government policy-making, says the Hong Kong committee for the United Nation Children's Fund (Unicef). A Unicef photo competition attracted entries from 334 primary and secondary students - aged between eight and 17 - who voiced their thoughts on life and social issues in Hong Kong. About 3,000 photos were submitted in April and May on the theme 'I want to tell YOU ...' The students expressed their ideas on various topics, such as the environment, public health, freedom, personal growth and emotions. The photos and captions were studied by child psychology and sociology experts at the Chinese University of Hong Kong (CUHK), who came up with interesting findings. Sociologist Chan Kin-man said one-third of the pictures were related to social issues, among which the most popular topic was environmental protection. In the captions, the students complained about air pollution and the reclamation projects in Victoria Harbour. They also called on the public to recycle waste, stop smoking and improve hygiene standards. 'Other popular topics included human rights and freedom of speech. They showed they were capable of addressing these serious social issues,' said Dr Chan, assistant professor of CUHK's sociology department. Many of the submissions were addressed to Chief Executive Donald Tsang Yam-kuen, even though he was only a candidate for his current title at the time of the competition. 'The kids knew he would get the job. There were pictures urging Mr Tsang to halt the reclamation on Victoria Harbour, to 'green' Hong Kong, provide more ambulances, put more resources into social work, and replace the current electric trams with magnetic trams,' Dr Chan said. CUHK child psychologist Lin Siu-fung said Hong Kong students were not as good at expressing emotions, compared with their counterparts around the world. 'They are more willing to deliver non-personal messages. For example, for social issues, the participants tended to shoot landscapes more than other subjects, such as humans, animals or personal belongings,' said Dr Lin. She added that the photos taken by primary school pupils showed their ideas and concerns could run deep, while the use of metaphors was common among the work of secondary school students. 'They have their own ideas and independent thinking but they don't express them directly. And they also don't have a chance to voice their opinions.' Rosanna Chan, Unicef advocacy and development officer, suggested that a permanent, child-friendly platform should be set up for children to express their views to the government. 'Children are part of the community and they have their right to express their concerns,' Ms Chan said. 'They can see what [adults] cannot.' Unicef will send the photos with the study reports to various government departments and the chief executive.