Air pollution at Hong Kong's busiest cargo pier fell significantly in the first week of July after all ocean-going vessels changed to low-sulfur fuels to comply with new regulations, a local air quality concern group has found.

However the group, Clean Air Network (CAN), still urged the environment authority to work more closely with governments in the Pearl River Delta (PRD) to further lower the city's marine emissions.

According to CAN, average 24-hour concentrations of toxic sulfur dioxide (SO2) in Kwai Chung Container Terminal stood at 12 micrograms (ug) per cubic meter between July 1 and July 7, a sharp drop from 24 ug per cubic meter the week before.

The figure was also down from 34 ug per cubic meter last year, according to CAN's study.

The new regulation, which came into effect on July 1, requires all ocean-bound vessels to switch to low-sulfur fuel with a mandatory 0.5 percent cap at berth in Hong Kong waters. This was after ships were shown in recent research to be the biggest source of SO2 in the city, followed by power generation.

In 2014, the Kwai Chung Container Terminal handled 17.6 million standard cargo units, representing 79 percent of the city's container throughput, ranking it the world's fourth biggest.

CAN praised the government's efforts but demanded more stringent regulations. This is to further improve the air quality as the current 24-hour average objective for SO2 stood at 125 ug per cubic meter, which it felt was "too lax".

Meanwhile, it also urged the Environmental Protection Department (EPD) to speed up coordination with the PRD governments to set up an emission control area within the greater PRD waters.

The EPD defended its assessment system, saying the European Union has also adopted the same limit Hong Kong has.

The World Health Organization's air quality standards include ultimate targets and interim targets. Hong Kong is improving air quality progressively toward the ultimate target, which was set at 20 ug per cubic meter in 24 hours, the EPD said.

luisliu@chinadailyhk.com

(HK Edition 07/10/2015 page6)