More research needed on reasons for increasing Ozone levels in the region – Researcher

Local research backs the recent conclusions by a joint air quality monitoring network that the levels of suspended particulates have improved, a local researcher told MNA, however more studies are required to assess the reasons why Ozone levels have gradually increased.

Yesterday, the Guangdong-Hong Kong-Macau Pearl River Delta Regional Air Quality Monitoring Network revealed its 2019 monitoring results, which seem to indicate that the average annual concentration levels of sulphur dioxide (SO2), respirable suspended particulates (RSP) and nitrogen dioxide (NO2) have decreased since 2006.

However, in the same period average annual concentration level of ozone (O3) increased by 36 per cent, with the report suggesting that ‘further alleviation of regional photochemical pollution is required’.

According to Thomas Lei – a University of Saint Joseph air pollution researcher – Ozone can be as negative to residents’ health as suspended particles and the reasons for the increase in regional levels is still to be exactly assessed.

Ozone is a reactive gas that can trigger a variety of health problems including chest pain, coughing, throat irritation, and airway inflammation, and can worsen bronchitis, emphysema, and asthma and respiratory problems

“Since PM10, PM2.5, NO2, and SO2 are mostly primary pollutants, it would be easier to predict and implement measures to lower these pollutant concentrations. However, O3 is a secondary pollutant, which is formed by VOCs and NOx reacted under the sunlight, making it more difficult to fully understand and thus to implement measures to keep the Olevels down,” Lei told MNA.

Lei considered that the reasons for the increase could maybe be attributed to higher temperatures in recent years and increased sunlight levels, with the same trend also reported in Northern China.

USJ also recently conducted a research 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.

‘”The levels of PM2.5 and O3 concentration has reached a record low during the initial outbreak of COVID-19 in late January 2020 and continue into February 2020 as the government introduced a 15 days casino closures as part of the preventive measures in Macau,’ the researcher noted.

However, levels of PM2.5 and O3 concentrations quickly returned to normal in March 2020, in particular of the levels of O3 concentration has exceeded the levels in comparison to the previous year of 2019.

Therefore Lei indicated that the university is planning further studies on the increase in O3 concentrations, with immediate plans also for a study on air pollution levels impacting the population in Ka-Ho village.

“They have a lot of schools in Ká Hó and many residents are complaining about rising pollution levels and we are going to investigate the air quality this year. The area does not have many people by it has a lot of heavy vehicle traffic and industry. A tunnel is currently being constructed and we are expecting that even more traffic and higher pollution levels will be reported,” Lei added.

A tunnel connecting Estrada de Nossa Senhora de Ká Hó with the Macau International Airport main avenue is currently on-going and is planned to be completed in 2021.