Hong Kong, Nov 25 - Four billion fewer plastic bags a year are being thrown out with the rubbish by Hong Kong people as the city's environmental consciousness grows, officials said Wednesday.

A government study found there had been a 66.5-percent drop in the number of plastic bags thrown away in the past four years from 8.7 billion a year to 4.6 billion.

In 2005, the average Hong Kong person threw away three plastic bags a day. That figure has now fallen to just 1.8 per person, according to the Environmental Protection Department.

Since the survey was conducted in June, a levy of 50 Hong Kong cents (6.5 US cents) per bag has been introduced in shops and supermarkets and is expected to lead to a further fall in plastic bags going to landfills.

The city of seven million still throws away more plastic bags per person than countries such as Australia, where the rate is one per person per day, and Ireland, where the rate is 0.9, officials said.

The introduction of the plastic bag levy triggered fierce opposition from industry groups who claimed it would unfairly penalise manufacturers and retailers.  (dpa)