Air quality decreases in recovery MCO


THE old agitation returns in our cities and villages.

More and more businesses are reopening, buyers are crowding in shopping malls, and the public can now travel freely across states.

However, these increased movements and activities have led to a slight deterioration in air quality in our country in the past month.

Regions like Penang, Ipoh, Shah Alam, Kuantan, Seremban, Melaka, Pasir Gudang, Kuching and Kota Kinabalu have shown a spike in nitrogen dioxide – a gas produced mainly from motor vehicles.

“These places have seen increases ranging from 1% to 157% between June 10 and 22,” reveals the Department of the Environment (DOE) to Sunday Star.

More sulfur dioxide was also detected in the air during the recovery movement control order (MCO) in the Klang valley, the department said.

Sulfur dioxide is an air pollutant generally produced by fuel combustion equipment, especially stations that produce electricity, industries and vehicles.

“This gas increased between 5% and 64% during the MCO recovery period from June 10 to 22,” said DOE, which collected readings from Batu Muda and Cheras stations in Kuala Lumpur, Putrajaya, Petaling Jaya, Shah Alam, Klang and Banting.

A similar result was also observed in Penang, Ipoh, Shah Alam, Kuantan, Seremban, Melaka, Pasir Gudang, Kuching and Kota Kinabalu.

The good news, however, is this: despite the increase in these gases, the air we breathe now is always cleaner in general, compared to the day before the MCO.

Several other air pollutants such as fine particles in the air (PM2.5), carbon monoxide and ground-level ozone (“bad” ozone) have decreased in recovery MCO, according to DOE data.

The MCO, which took effect on March 18 to contain the spread of Covid-19, has seen movement restricted while non-essential services and businesses have been temporarily suspended.

These reduced activities have led to fresher air across the country, the Sunday Star reported on March 29.

However, as the government relaxed more restrictions on recovery MCO from June 10, air quality began to decline.

“The increased use of vehicles and industrial activities are important factors influencing the trend of air quality in the country.

“This has been proven when there has been an increase in air pollutants following the government’s decision to relax restrictions during the conditional MCO and the recovery MCO, although not all activities are fully authorized,” explains the department.

Improvements in air quality were recorded at all stages of the AGC, but these improvements became less apparent during the recovery period of the AGC between June 10 and 22.

Based on DOE readings, air quality improved the most, by 53% during the conditional OLS phase between May 4 and June 9.

The air was coolest during this period, the number of days with “good” air pollutant index (API) readings increasing by 53% compared to before the AGC, between March 1 and 17 .

During the conditional MCO, interstate travel was still prohibited unless the population was authorized by the police to do so.

At that time, many companies had also introduced home work arrangements among staff, while some professions were still not allowed to return to work.

This has led many people to spend more time at home and therefore reduce emissions.

From March 18 to May 3, Malaysians spent around 30% to 40% longer at home than an ordinary day in January or February, according to the Google Covid-19 report on trends in community mobility in

In the conditional MCO from May 4 to June 9, they stayed at home about 15% to 30% longer.

And during the recovery MCO from June 10 to 24, people spent around 5% to 15% more time at home.

This data in the report was collected anonymously from applications like Google Maps, and showed how people’s movements have changed throughout the pandemic.

When recovery MCO started on June 10 – a phase that lifted the ban on interstate travel, air quality improved only 32% from pre-MCO days.

“The government had also allowed many commercial and industrial premises to operate again while many were allowed to go out to carry out activities,” said the DOE.

Principal investigator at the Institute of Ocean and Earth Sciences, Professor Datuk Dr Azizan Abu Samah agrees that the amount of pollutants in the air has increased, based on his observations.

He and his team had monitored air quality around the Klang Valley from six stations during the MCO.

There have been a spike in vehicle emissions such as nitrogen dioxide and carbon monoxide.

“But the concentration is lower than before the start of the AGC in early March,” he said.

“According to the data, there was an increase in the level of particles floating in the air, or PM2.5 and PM10 towards the end of May,” explains Professor Azizan.

The tip of these particles in the air, he suggests, is due to activities such as the burning of biomass by farmers in Sumatra, Indonesia, while the direction of the wind blows smoke towards the Klang Valley .

Professor Azizan warns that biomass burning in Sumatra should normally start from July to September.

“As such, we need to start monitoring hot spots and engaging with Indonesia on such incidents to prevent further pollution of the air we breathe,” he added.


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