The Australian government has defended its decision to cite air pollution in Hong Kong in a new travel warning. It said a change to its travel advice for the city, highlighting the potential health impacts of air pollution, was timely as part of a 'comprehensive, consistent and factual' warning. The South China Morning Post reported yesterday that Australia's Department of Foreign Affairs had included a notice about air pollution in Hong Kong as a health issue as part of an updated alert on Monday. It warned that air pollution levels could 'aggravate bronchial, sinus or asthma conditions', and that people with heart or respiratory illnesses should reduce physical exertion and outdoor activities on days when very high pollution levels were recorded. Yesterday, a spokesman for the department said the change to the travel advice brought it in line with 'similarly affected' places and used the Hong Kong government's own health advice to its citizens. 'The Australian government has an obligation to notify its citizens to circumstances that may affect their welfare when travelling,' he said. But a spokesman for lobby group Clear The Air said the advice was not up to date as it used government data that relied on old standards and did not reflect current World Health Organisation air quality standards. The WHO's standards for measuring air pollution are stricter than those used by the Hong Kong government.