Since the beginning of the COVID-19 pandemic, people worldwide have felt the effects of its rapid spread – citywide lockdowns, travel restrictions and strict safety measures.
Yet, its impact does not stop at effects on everyday activities – it has also affected air, water, soil, and carbon emissions.
Researchers from Xi’an Jiaotong-Liverpool University (XJTLU) recently published a comprehensive, systematic picture of the pandemic’s impacts – both positive and negative – on environmental pollution and carbon emissions on different continents.
A team, led by Dr Pow Seng Yap from XJTLU’s Department of Civil Engineering, analysed data from at least 25 countries published in more than 100 peer-reviewed papers and publications that focused on variations of environmental impacts on those countries.
From left to right: Lin Chen, Dr Pow Seng Yap, Mingyu Yang (not pictured: Goodluck Msigwa)
The literature review, recently published in Science of the Total Environment, identified both positive and negative impacts resulting from pandemic-control measures like lockdowns.
Global water quality positively impacted
The review found the most significant positive impact was on water quality, says Dr Yap, who is XJTLU’s Programme Director of MSc Sustainable Construction.
“During the COVID-19 lockdowns, the quality of surface water, coastal water and groundwater around the globe all greatly improved due to fewer commercial activities at beaches and harbours, and there was less sewage, industrial effluence and agricultural wastewater.”
However, the reduction in water pollution did not significantly occur everywhere, the researchers found.
“A few reservoirs and coastal areas were further contaminated, such as in South America, due to the lack of management and improper disposal of plastic waste,” he says.
Changes of surface water pollution, coastal water pollution and groundwater pollution in different global regions during COVID-19; reproduced with permission from Yang et al. (2022), Copyright 2022, Elsevier
Improved global air quality
Air pollutants like nitrogen dioxide (NO2) and carbon monoxide (CO) were reduced in most regions during pandemic lockdown phases, Dr Yap says.
“This is because many governments restricted activities that cause air pollution, such as transportation, industrial activities, refineries and agriculture, through imposed measures like lockdown and social distancing,” he explains.
The review did find that sulphur dioxide (SO2) and ozone (O3) levels increased because fossil fuel-combusting power plants and industries that produce these pollutants continued operations even during the lockdown.
Fewer greenhouse emissions
The review noted that the International Energy Agency (IEA) reported first-quarter 2020 global carbon emissions at a 5% decline compared to the same quarter in 2019 due to a drop in global energy demand.
“Because the lockdown stopped many activities that normally burn fossil fuels, the emissions of carbon and other greenhouse gases were reduced,” Dr Yap says.
“The only increase in carbon emissions we found came from the operation of tankers and bulk carriers, because shipping continued during lockdowns and other travel restriction periods to keep supply chains moving.”
Negative: Global soil
The most significant negative impact of COVID-19 on the global environment the study identified was soil contamination from throw-away face coverings.
“Masks have become necessary for people going to work or school, shopping, and many other activities, leading to a large number of used masks and other disposable personal protective equipment,” Dr Yap says.
“These have led to a continued increase and accumulation of solid waste and contamination of the soil.”
Moreover, he says, soil contamination due to these items may continue to increase.
“People will need to continue using masks and protective clothing daily due to the unpredictable mutation, rapid transmission and generally long incubation period of COVID-19,” he says.
The paper notes that when pandemic restrictions were lifted, environmental problems that had lessened appeared to flare up once again.
“Therefore, we’d like to put forward strategies to prolong the beneficial effects of COVID-19 on air and water while minimising the negative impact on soil,” Dr Yap says.
The research team suggests that governments establish laws and regulations for air and water pollution control – for example, higher taxation on pollutants. The team also recommends prioritising clean energies to reduce the burning of fossil fuels.
To mitigate soil pollution, governments should establish a strict and reliable waste management system for the disposal of hazardous waste as well as parameters for the amount of waste that can be released into the environment, Dr Yap says.
“Reusable masks that are antibacterial can be further developed to reduce the waste. On a personal level, people should try to choose packs of masks instead of those individually packaged with plastic pockets, and discard masks according to the waste classification principle after use,” he says.
The XJTLU research team consists of Dr Pow Seng Yap, Mingyu Yang, Lin Chen, and Goodluck Msigwa.
The paper, ‘Implications of COVID-19 on global environmental pollution and carbon emissions with strategies for sustainability in the COVID-19 era’, is available online here.
By Yi Qian
Edited by Patricia Pieterse and Tamara Kaup