Hello friends! Hello Prof!
Due to the pandemic, the local government announced a nationwide lockdown, also known as a circuit breaker (Abu Baker, 2020). This was carried out from 7 April to 1 June 2020. With the implementation of this measure, everyone had to stay home unless they were essential workers. Those few months were difficult for most of us, having to transition from commuting daily to staying home without a choice. However, our environment has benefited from the lack of human presence. In this post, we will be discussing how the air around us changed due to the lockdown.
The National Environment Agency (NEA) reported that in the first 2 weeks before lockdown, the air quality improved (Tan, 2020). For example, the average levels of particulate matter, carbon monoxide (CO) and sulphur dioxide (SO2) decreased from 8 to 43 per cent. This may be due to a decrease in road traffic as people started to work from home and industries slowed down their activities.
During the lockdown period, there was a reduction in the national Pollutant Standards Index (PSI) by 19% which signals the positive impact of COVID-19 on air pollution levels (Li & Tartarini, 2020). The reduction rates were spatially uneven; the highest rates were found in the southern area of Singapore (29%) and the lowest rates in the west and north of Singapore (17%) (Li & Tartarini, 2020). This could be attributed to the spatial distribution of outdoor pollutants as the main sources of pollution – heavy industries, refineries and the harbor – are located in the south-western part of Singapore.
Fig. 1: Shows the mean tropospheric column concentrations of NO2 (left side) and SO2 (right side) from 7th of April and 11th of May 2019 (top side) and 2020 (bottom side). Data were obtained from the ESA Copernicus Sentinel 5P satellite.
Looking at Fig. 2, the biggest reduction of SO2 concentrations can be seen in Pulau Bukom, mainly due to the reduction of petrochemical activities in COVID-19 times (Li & Tartarini, 2020). NO2 concentrations also decreased in the Eastern side of Singapore, possibly attributed to the reduction in flights at Changi Airport.
That said, could we say that the pandemic – though it is indeed a bane to society as it disrupts every facet of life – is a boon to the environment? Was it a much needed break for our ecology?
While this has indeed benefited us in reducing air pollutants, COVID-19 has indeed spurred pollution in other aspects for Singaporeans. Check back in to our next post this week as we uncover the rise of biohazardous medical waste in Singapore!
References
Abu Baker, J (2020). Singapore’s circuit breaker and beyond: Timeline of the COVID-19 reality. [online] CNA. Available at: https://www.channelnewsasia.com/news/singapore/covid-19-circuit-breaker-chronicles-charting-evolution-12779048 [Accessed 6 Sep. 2020].
Tan, C. (2020). Coronavirus: Air quality improves as Singapore slows down under circuit breaker measures. [online] The Straits Times. Available at: https://www.straitstimes.com/singapore/transport/coronavirus-air-quality-improves-as-singapore-slows-down-under-circuit-breaker [Accessed 6 Sep. 2020].
Li, J., and Tartarini, F. (2020). Changes in Air Quality during the COVID-19 Lockdown in Singapore and Associations with Human Mobility Trends. Aerosol and Air Quality Research, [online] 20(8), pp.1748–1758. Available at: https://aaqr.org/articles/aaqr-20-06-covid-0303 [Accessed 6 Sep. 2020].