At least 160 sites in the city's busiest districts still keep neon signs and lights switched on early in the morning despite increased public awareness of the effects of light pollution, a green group's survey has found. Friends of the Earth recently reviewed the results of its anti-light-pollution campaign by revisiting on May 16 sites in places such as Mong Kok, Causeway Bay and Central where the group had found wasteful lighting practices. It found that at more than 160 sites the exterior lights of buildings, neon signs and spotlights remained on at various times from midnight to 5am. Neon signs for the Wynn casino in Macau and TCL electronics manufacturer on two buildings at Gloucester Road in Wan Chai were on until 4am and 2am, respectively. About 300 spotlights on the street level of the Emperor Group's office tower in Hennessy Road, Wan Chai, were also still lit early in the morning. At Jardine's Crescent in Causeway Bay, the Bonjour Cosmetics chain was also wasting the energy efficiency of LEDs (light-emitting diodes) by keeping them on after midnight. However, the green group also reported that some luxury goods retailers such as Prada's flagship store in Central had responded positively to calls to reduce light pollution. The group exposed Prada last year as one of the worst for keeping its exterior and interior lights on overnight. But the brand later decided to turn them off after midnight. Apart from Prada, the H&M branch in Central also cut its lighting hours. 'We have seen positive responses over the past year. But those that have made changes are still a minority. The culture of competing on brightness is deep-rooted in the city,' Hahn Chu Hon-keung, environmental affairs manager of the group, said. 'A genuine change can only be made possible by a law regulating light pollution.' Mr Chu, who has spent many nights wandering the streets recording what the group called 'ridiculous lighting', said the city's light pollution had attracted overseas attention, with a Taiwanese architecture professor describing it as 'violent urban lighting' that amounted to 'bad taste of city aesthetics'. He said that in one case, a bank in Central had ignored a light-nuisance complaint from a Mid-Levels resident who found the neon signs on its Garden Road tower too bright. The bank told the complainant that the lights needed to be on because it was in Central - 'the heart of commercial activities'. The group is organising a lights-out campaign to be held on June 21 to promote energy saving and minimise light pollution. It has also persuaded more than 600 businesses and buildings to pledge to turn off their lights before midnight. Voting for the top 10 'ridiculous lighting' culprits in the city is being held at the Friends of the Earth website, www.foe.org.hk .