Air quality improved in recent months, no concrete data on marine environment – Experts

According to the Macau government, environmental researchers and activists heard by Macau News Agency (MNA), there has been a reduction in atmospheric pollution in Macau in the first months of this year that coincided with the Covid-19 crisis, but that more detailed studies are required to assess if water pollution has declined.

Recently footage surfaced of white dolphins swimming in Macau in the riverside near NAPE, a staple species of the region that has seen its population numbers greatly impacted by the construction of the Hong Kong-Zhuhai-Macau Bridge, increased ferry traffic and marine pollution.

Similar images and footage showing a return of wildlife to urban areas left abandoned due to social distancing measures imposed worldwide have become commonplace in the last months, but environmental activists warned it takes more to recover debilitated ecosystems.

“Less ferry disturbance and industrial discharge in the delta within the dolphin habitat will help. But the temporary effect may not last long. Recovery of threatened species also takes time and so does collecting the evidence of it,” Viena Mak, spokeswoman for the Hong Kong Dolphin Conservation Society told MNA.

Mak noted that there is no published data on the number of Chinese white dolphins in the past few months and that only when updated data is published in August by the Hong Kong government would it be possible to see if there has in fact been a rebound in the white dolphin population.

Meanwhile, Daphne Wong, a filmmaker known for her work with white dolphin conservation, told MNA that so far there does not seem to be evidence showing pollution has reduced with the pandemic.

“In fact, there are more masks found floating around in the sea,” Wong noted.

According to the filmmaker, dolphins can sometimes be seen feeding – as in the social media video – and are often spotted off the coast of Macau or when crossing the bridge to Hong Kong.

MNA inquired the Environmental Protection Bureau (DSPA) if there has been an improvement in water quality and the marine environment in Macau for the last months, but the department was non-commital.

“Changes in seawater quality are affected by many factors and the correlation between the water changes and the pandemic could not be determined,” the department noted.

Still, recently the department had indicated that pollution along the riverside in the Areia Preta district has decreased considerably since wastewater control in the area was improved.

However, the DSPA has admitted that a recent improvement in Macau’s air quality could be a result of the reduction in local emissions.

“The atmospheric environment of Macau is affected by regional and local factors and is related to natural conditions and human activities. Therefore, the recent improvement in Macau air quality could be due to lower regional and local emissions,” the DSPA told MNA.

Concerning atmospheric pollution, Thomas Lei, a researcher at the University of Saint Joseph with a focus on air pollution has informed MNA that the university’s research team has been “working intensively” on the analysis of the Covid-19 pandemic in relation to the air quality in Macau, and has found that the levels of PM2.5 fine particulate concentration have dropped significantly from January to March 2020 in comparison to the previous year of 2019.

However, the research also showed that the levels of maximum hourly Ozone (O) have been higher in the first three months of this year, which Lei considered being possibly related to the lower emission of Nitrogen dioxide (NO2).

According to the 2018 annual report released by the DSPA – the most recent available – the main cause of air pollution in Macau was ozone.

“As shown in the graphs, the difference in monthly average concentration for PM2.5 (from January to March) between 2019 and 2020 is a decrease of 16 micrograms (μg)/m3, 2 μg/m3, and 1 μg/m3 respectively, while the difference in monthly average concentration (from January to March) between 2019 and 2020 for Ois an increase of 12 μg/m3, 21 μg/m3, and 9 μg/m3 respectively,’ Lei noted.

This description matches the information provided by the Meteorological and Geophysical Bureau (SMG), which indicated that average levels of PM2.5 had decreased 39 per cent year-on-year in January and February when compared to the previous two months, with NO2 levels falling by 29 per cent.

Meanwhile, January and February also saw the number of ‘good air quality’ days go up 190 per cent to about 30 days.

However, the SMG is known to evaluate the concentration limit of fine particulate matter in Macau at an annual level of 35 μg per cubic metre, a number that is much higher than the WHO standard of 10 μg per cubic metre.

‘The main reasons being the decrease in traffic flow and the reduction of gas emissions from motor vehicles. However, it should also be noted that weather conditions are elements that can affect air quality, and this variation cannot be explained from a single perspective,’ the SMG indicated.

‘With regard to carbon dioxide (CO2), emissions are mainly related to the consumption of petrochemical fuel. With the widespread reduction in social activities after the Chinese New Year, the emission of CO2 was expected to decrease slightly.’

MNA repeatedly asked the SMG for more updated atmospherical data but no reply had been provided when this article was published.

However, unfortunately as business resumes in Mainland China and Macau, pollution levels seem to be going back to normal, with the SMG having returned to issue warnings for vulnerable residents to avoid outdoor activities due to atmospheric pollution.