Sound bite: COVID-19 and Noise Pollution

In 2019, the COVID-19 brought a halt and reduction in economic activity. Naturally, industries and traffic were reduced as some cities entered lockdown to control the spread of the disease. What effect would these have on noise pollution?

COVID-19 and Sources of Noise Pollution

Noise Pollution in the Air

Research on health and aircraft noise exposure has found that long-term exposure to aircraft noise may increase the prevalence of arterial hypertension (Rojek et al., 2019). A short-term reduction in aircraft noise, as with COVID-19 and restrictions on travel may reverse arterial stiffness effects and blood pressure. For individuals exposed to frequent noise from aircrafts, or those who live near airports, this is significant.

Noise Pollution in the Ocean

From January 2020, worldwide travel restrictions and slowdowns in the economy in response to the pandemic led to a decline in anthropogenic activity in the ocean (Tyack et al., 2021). This has enabled scientists to leverage this and determine how a decrease in human activities might affect sound levels in the ocean. The International Quiet Ocean Experiment (IQOE), launched in 2015 with the goal of researching ocean sound and its effects on marine biology, has encouraged the deployment of civilian hydrophones to create time series of ambient sound measurements in the ocean. 231 such hydrophones have been identified, which could potentially contribute to a worldwide analysis of COVID-19 on ocean sound.

In conducting this long-term research, it is critical that monitoring extends through 2021, such that researchers can observe a return to the baseline condition. While there are challenges in the recovery of data, the IQOE welcomes an expansion of this global acoustic network to improve our understanding of the impacts humans have on marine ecosystems (Tyack et al., 2021).

Further, a study of the cold-water coral Tisler reef found that overall noise levels dropped significantly after the closure of the border between Norway and Sweden as a result of COVID-19 (De Clippele and Risch, 2021). A long-term acoustic recorder was deployed from January to May 2020, and lockdown measures from 15 March stopped passenger vessel traffic between the two countries. COVID-19 border closer can be said to reduce noise levels by 7 dB on average during the day. This research, together with other noise pollution experiments, provides “valuable insights” to understand how exactly noise pollution affects marine ecosystem function (De Clippele and Risch, 2021).

COVID-19 and Effects of Noise Pollution

Effects on Animals

On land, studies have shown that noise pollution has forced male birds to sing louder songs such that they can be heard by rivals and mates (Stokstad, 2020). Behavioural ecologists at the University of Tennessee have conducted a long-term study of white-crowned sparrows around San Francisco, referencing recordings from the 1970s. They have discovered that as traffic levels increased, the lowest frequencies of the sparrows’ songs rose such that they would not be drowned out by vehicles, effectively narrowing the total bandwidth of their communication. Research has shown that the resulting stress from being in noisy environments can speed aging in birds and disrupt their metabolisms. The surrounding din may also prevent birds from hearing their own chicks or the warning of fellow birds (Stokstad, 2020).

During the pandemic, the birds in San Francisco and the surrounding areas were singing 30% softer than before the lockdown. They were also singing songs with bandwidths like that of birds in the 1970s. This finding brings optimism, as it shows that sparrows can adjust their songs to adapt to the environment. Further, species with more flexible behaviour would be able to cope with changing environments, and reducing noise could promote the return of more noise-sensitive bird species to cities (Stokstad, 2020).

Effects on Humans

While research and experiments during the pandemic have brought about newfound hope for animals and ecosystems, there are also interesting findings on the effects of anthropogenic noise on humans. With the ceasing of traffic and human activity during lockdown periods, there was an indisputable reduction in noise levels inside and outside the home. For instance, compared to April 2019, Italy’s traffic decreased by 79% in April 2020 (Caniato, Bettarello, and Gasparella, 2021). Restrictions on work, school and other activities also led to a significant decrease in the level of outdoor noise (Caniato, Bettarello and Gasparella, 2021). This new soundscape granted more indoor silence for certain areas. Sounds of nature also increased during the lockdown. In a global survey with respondents largely from Europe and the Americas, it was discovered that people enjoyed the quieter conditions as a result of the pandemic, and expressed a desire to maintain lower outdoor noise levels (Caniato, Bettarello and Gasparella, 2021).

However, as activities shifted from outdoors to the indoors, there have also been greater outrage and frustration at neighbours. Lee and Jeong conducted a study on noise perception in the UK before and after lockdown. According to their findings, tweets about noise complaints doubled after the lockdown, compared to the same periods in 2019. Data from a questionnaire survey found that respondents perceived a decrease in outdoor noise levels, but an increase in neighbour noise levels. The former finding corresponds with other studies, much like the study outlined in the previous paragraph. This was attributed to increases in talking, shouting and TV/music activities, which was a source of annoyance for respondents (Lee and Jeong, 2021). This indicates that existing sound insulation within buildings can be reinforced to reduce distractions within the home. As remote working is now incorporated into the working lifestyle, this could be an area to look into in the future.

Research in India conveys the relatively low priority of noise as a hindrance to health. Existing noise pollution controls are highly inadequate, although noise was regarded as a pollutant under the Air Prevention and Control of Pollution Act of 1981 (Kumar & Naik, 2022). During the COVID-19 pandemic, noise pollution was reported to have decreased by 40% in the port city of Karachi (Kumar & Naik, 2022).

I recognise that many of these studies are limited where their localities are specific, and findings may not apply to larger regions due to variabilities. However, these still provide some guidelines on the areas we can work on as a species to reduce noise pollution globally for ourselves, and the other beings we share the Earth with.

 

 

References

De Clippele, L.H. and Risch, D. (2021). Measuring Sound at a Cold-Water Coral Reef to Assess the Impact of COVID-19 on Noise Pollution. Frontiers in Marine Science, 8.