Hong Kong will shiver its way out of 2013, with the cold, smoggy spell set to continue in the last few days of the year as polluted air flows in from the mainland.
The government opened cold-weather shelters for a third day yesterday and four elderly people were sent to hospital with hypothermia as the city recorded some of its lowest temperatures in three years. Two of the four people in hospital were in a serious condition last night.
Ta Kwu Ling, in the northern New Territories, saw temperatures drop to 2.7 degrees Celsius - the lowest in three years - while city averages ranged from 10 to 15 degrees Celsius.
"The elderly have less insulating fat beneath their skin to keep them warm, and their body temperature control mechanism may be weaker. Their bodies may not be able to appropriately respond to the cold weather," a Department of Health statement said. It urged the public, particularly the sick and elderly, to take precautions against the cold.
"Cold weather can easily trigger diseases, especially among the elderly and people suffering from heart disease, respiratory illness or chronic illnesses," the statement said.
The department urged Hongkongers to wrap up in adequate clothing, eat enough food, do exercise to keep warm and avoid being outdoors for long periods.
Meanwhile, roadside monitoring stations in Central, Causeway Bay and Mong Kok yesterday registered high and very high levels of pollution - with a peak of 140 in Central.
The air pollution index measures concentrations of major pollutants such as carbon monoxide and respirable suspended particulates in a range of 0 to 500. Readings above 51 are "high" - acceptable in the short term, but beyond long-term health standards. "Very high" is above 100, indicating air that is unhealthy in both the short and long term.
It has been a smoggy year overall, with only three out of 11 non-roadside stations recording days with low pollution. Last year, all stations recorded some days of low pollution.
Roadside monitoring stations in some of the busiest pedestrian thoroughfares - Causeway Bay, Central and Mong Kok - recorded mostly high and very high pollution levels. This was probably due to wind and weather conditions keeping the pollutants trapped in urban areas, said Kwong sum-ying, chief executive of the Clean Air Network.
Local vehicle emissions were the main source of roadside pollution, she added. "We used to think that LPG was better for the environment, but because the converters in many taxis and buses haven't been changed, they're not filtering out the pollutants," Kwong said.
The government is offering a one-time subsidy to drivers to replace the converters.