Jakarta ranks first as city with the worst air quality in Southeast Asia last year, a recent study has shown.

The study by Greenpeace and AirVisual IQ published on March 5, monitored air quality in hundreds of cities across the globe. Jakarta was ranked first, followed by Hanoi, for the worst air quality, the head of Greenpeace Indonesia, Leonard Simanjuntak, said.

Across the globe, Leonard added, Jakarta was ranked 161st for cities with the worst air quality. New Delhi was in first place.

“Four- and two-wheeled vehicles exceed Jakarta's capacity. There is almost no control over them. It’s easier for people to use private vehicles in Jakarta,” he said as quoted by kompas.com on Thursday.

Another factor, according to Greenpeace, was coal-fired steam power plants (PLTU) located around Jakarta. The PLTUs contributed 33 to 36 percent to air pollution in Jakarta.

“There are PLTUs around Jakarta that are situated within a 100-meter radius of each other. It also contributes seriously to the level of air pollution in Jakarta," Leonard said.

He explained that the daily air quality average in Jakarta, according to the PM 2.5 indicator, last year was 45.3 micrograms pollutant particles per cubic meter.

"The daily average air quality in Jakarta is 4.5 times worse than the limit set by the World Health Organization [WHO]. That number also increased compared to 2017, when the average daily air quality in Jakarta was 29.7," Leonard said.

The WHO has set an average air quality guideline of 25 micrograms per cubic meter daily. (ggq)