Data regarding the perceived air pollution are collected by means of an online survey distributed between 11-05-2020 and 31-05-2020 in Australia, Brazil, China, Ghana, Italy, India, Iran, Norway, South Africa and the United States.

The survey respondents are asked to evaluate the perceived air pollution quality before and during the COVID-19 restrictions according to a Likert scale varying from "1=extremely low/absent" to "7= extremely high". Overall, the data shows that an improvement in air quality is perceived by the respondents in all the ten investigated countries.

The online survey has been created with Google Forms and WenJuanXing and conveniently translated into Chinese, English, Italian, Norwegian, Persian, Portuguese and has been distributed via email, social media and professional networks. Overall, the total number of respondents is approximately equal to 10 000.

Intercorrelations among variables.

Noise pollution in cities has major negative effects on the health of both humans and wildlife. Using iPhones, we collected sound-level data at hundreds of locations in four areas of Boston, Massachusetts (USA) before, during, and after the fall 2020 pandemic lockdown, during which most people were required to remain at home. These spatially dispersed measurements allowed us to make detailed maps of noise pollution that are not possible when using standard fixed sound equipment. The four sites were: the Boston University campus (which sits between two highways), the Fenway/Longwood area (which includes an urban park and several hospitals), Harvard Square (home of Harvard University), and East Boston (a residential area near Logan Airport). Across all four sites, sound levels averaged 6.4 dB lower during the pandemic lockdown than after. Fewer high noise measurements occurred during lockdown as well. The resulting sound maps highlight noisy locations such as traffic intersections and quiet locations such as parks. This project demonstrates that changes in human activity can reduce noise pollution and that simple smartphone technology can be used to make highly detailed maps of noise pollution that identify sources of high sound levels potentially harmful to humans in urban environments. Methods We collected sound measurements within four different urban sites in Boston, Massachusetts. Working in small teams of 2-4 people, we used the mobile app SPLnFFT to collect sound level data in A-weighted decibel readings using smartphones. We exclusively used iPhones for data collection for consistency in hardware and software. Before each collection, we calibrated each iPhone to the same standard, which was used for every collection outing. We recorded the L50 value (the median sound level) for each recording because the L50 value is less affected by short bursts of loud sound than the mean reading. Recordings ran for approximately 20 seconds each. We recorded all sound measurements between 9 am and 5 pm on workdays to avoid the influence of rush-hour traffic, and only collected data on days without rain, snow, or strong wind to prevent inaccuracies due to weather. Within these conditions, we collected sound measurements over multiple days and at different times to ensure representative data. We followed these procedures for both collection cycles (2020 during lockdown and 2021 after lockdown had been lifted). The 2017 data were collected for an unrelated noise pollution project conducted by previous members of the Primack Lab and were not collected with the exact parameters established for the 2020 and 2021 collections. However, we found these noise data to be valuable given that they could be used to compare lockdown sound levels to the soundscape before the COVID-19 pandemic. We used R Studio to create sound maps from the individual data points in a way that allows for spatial visualization of the soundscape before, during, and after the pandemic lockdown. To test for statistically significant differences in sound level between years, we performed Welch’s t-tests on the raw data for all sites comparing lockdown (2020) measurements to pre (2017) and post (2021) lockdown measurements. Given the hypothesis that 2020 would have lower sound levels at each site, we report the results of one-tailed t-tests.

Analysis of ‘Daily Air Pollution Data - India & USA’ provided by Analyst-2 (analyst-2.ai), based on source dataset retrieved from https://www.kaggle.com/sumandey/daily-air-quality-dataset-india on 28 January 2022.

--- Dataset description provided by original source is as follows ---

Context

Air Pollution is a major health concern of many. However, the COVID-19 pandemic might have some role to play in bringing some changes to the overall quality of air.

Content

The dataset consists of pm2.5 measurements from Jan 2019 to May 2021 of the Major Cities of India & the United States. You also need to understand how pm2.5 classifies Air Quality.

Acknowledgements

Special thanks go to https://aqicn.org for making the data open-source and use it for research purposes.

Inspiration

This data could be used to answer several questions -

• How the air quality been pre and post-Covid.
• How Air Quality varies across different cities.
• Can you forecast the values for the next 1 month.

You are open to coming up with your own analysis as well.

--- Original source retains full ownership of the source dataset ---

This is the data repository for publicly available data to reproduce analyses in Woodward, S., Wu, X., Hou, Z., Mork, D., Braun, D., Dominici, F., 2022. Combining aggregate and individual-level data to estimate individual-level associations between air pollution and COVID-19 mortality in the United States. For code, please visit https://github.com/NSAPH/PM_COVID_ecoinference/tree/main.

Demographic characteristics of the final sample.

Multiple linear regression predicting distance in pixels.

United States AQI: Oregon-Washington: Portland-Vancouver-Hillsboro data was reported at 36.000 Index in 16 May 2025. This records a decrease from the previous number of 42.000 Index for 15 May 2025. United States AQI: Oregon-Washington: Portland-Vancouver-Hillsboro data is updated daily, averaging 39.000 Index from Jan 1980 (Median) to 16 May 2025, with 16572 observations. The data reached an all-time high of 509.000 Index in 13 Sep 2020 and a record low of 12.000 Index in 05 Mar 2017. United States AQI: Oregon-Washington: Portland-Vancouver-Hillsboro data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: Montana: Billings data was reported at 12.000 Index in 16 May 2025. This records a decrease from the previous number of 13.000 Index for 15 May 2025. United States AQI: Montana: Billings data is updated daily, averaging 26.000 Index from Jan 1980 (Median) to 16 May 2025, with 16328 observations. The data reached an all-time high of 191.000 Index in 05 Sep 2023 and a record low of 0.000 Index in 11 Jan 2025. United States AQI: Montana: Billings data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: Mississippi: Jackson: NO2 data was reported at 11.000 Index in 30 Jun 2020. This records an increase from the previous number of 5.000 Index for 29 Jun 2020. United States AQI: Mississippi: Jackson: NO2 data is updated daily, averaging 15.000 Index from Jan 1980 (Median) to 30 Jun 2020, with 2068 observations. The data reached an all-time high of 103.000 Index in 23 Jun 1982 and a record low of 1.000 Index in 07 Jun 2020. United States AQI: Mississippi: Jackson: NO2 data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E001: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: Iowa: Des Moines-West Des Moines data was reported at 42.000 Index in 16 May 2025. This records a decrease from the previous number of 54.000 Index for 15 May 2025. United States AQI: Iowa: Des Moines-West Des Moines data is updated daily, averaging 40.000 Index from Jan 1980 (Median) to 16 May 2025, with 16472 observations. The data reached an all-time high of 186.000 Index in 04 Jul 2020 and a record low of 4.000 Index in 24 Dec 2020. United States AQI: Iowa: Des Moines-West Des Moines data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: New York: Rochester: Ozone data was reported at 58.000 Index in 16 May 2025. This records an increase from the previous number of 37.000 Index for 15 May 2025. United States AQI: New York: Rochester: Ozone data is updated daily, averaging 34.000 Index from Jan 1980 (Median) to 16 May 2025, with 16427 observations. The data reached an all-time high of 136.000 Index in 25 May 2016 and a record low of 9.000 Index in 02 Oct 2018. United States AQI: New York: Rochester: Ozone data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: Iowa: Des Moines-West Des Moines: NO2 data was reported at 4.000 Index in 30 Jun 2024. This records a decrease from the previous number of 6.000 Index for 29 Jun 2024. United States AQI: Iowa: Des Moines-West Des Moines: NO2 data is updated daily, averaging 12.000 Index from Apr 2001 (Median) to 30 Jun 2024, with 8051 observations. The data reached an all-time high of 50.000 Index in 05 Nov 2020 and a record low of 2.000 Index in 22 Jun 2024. United States AQI: Iowa: Des Moines-West Des Moines: NO2 data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E001: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: Idaho: Boise City data was reported at 46.000 Index in 16 May 2025. This records a decrease from the previous number of 67.000 Index for 15 May 2025. United States AQI: Idaho: Boise City data is updated daily, averaging 48.000 Index from Jan 1980 (Median) to 16 May 2025, with 15984 observations. The data reached an all-time high of 265.000 Index in 01 Sep 2024 and a record low of 10.000 Index in 20 May 2019. United States AQI: Idaho: Boise City data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: Maryland-West Virginia: Cumberland data was reported at 1.000 Index in 08 Jun 2020. This stayed constant from the previous number of 1.000 Index for 07 Jun 2020. United States AQI: Maryland-West Virginia: Cumberland data is updated daily, averaging 17.000 Index from Jan 1980 (Median) to 08 Jun 2020, with 7563 observations. The data reached an all-time high of 200.000 Index in 01 Feb 2018 and a record low of 0.000 Index in 20 Aug 2019. United States AQI: Maryland-West Virginia: Cumberland data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E001: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: New York: Rochester: SO2 data was reported at 0.000 Index in 30 Sep 2023. This stayed constant from the previous number of 0.000 Index for 29 Sep 2023. United States AQI: New York: Rochester: SO2 data is updated daily, averaging 0.000 Index from Jan 1980 (Median) to 30 Sep 2023, with 15723 observations. The data reached an all-time high of 51.000 Index in 27 Aug 2016 and a record low of 0.000 Index in 30 Sep 2023. United States AQI: New York: Rochester: SO2 data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E001: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: New York: Rochester: NO2 data was reported at 22.000 Index in 31 Dec 2024. This records an increase from the previous number of 5.000 Index for 30 Dec 2024. United States AQI: New York: Rochester: NO2 data is updated daily, averaging 13.000 Index from Feb 2011 (Median) to 31 Dec 2024, with 3691 observations. The data reached an all-time high of 51.000 Index in 28 Feb 2015 and a record low of 0.000 Index in 01 Oct 2011. United States AQI: New York: Rochester: NO2 data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E001: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: South Dakota: Sioux Falls: CO data was reported at 2.000 Index in 31 Dec 2024. This stayed constant from the previous number of 2.000 Index for 30 Dec 2024. United States AQI: South Dakota: Sioux Falls: CO data is updated daily, averaging 2.000 Index from Jan 2011 (Median) to 31 Dec 2024, with 4429 observations. The data reached an all-time high of 13.000 Index in 30 Jul 2021 and a record low of 1.000 Index in 25 Dec 2024. United States AQI: South Dakota: Sioux Falls: CO data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E001: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: Washington: Seattle-Tacoma-Bellevue data was reported at 35.000 Index in 16 May 2025. This records a decrease from the previous number of 44.000 Index for 15 May 2025. United States AQI: Washington: Seattle-Tacoma-Bellevue data is updated daily, averaging 45.000 Index from Jan 1980 (Median) to 16 May 2025, with 16573 observations. The data reached an all-time high of 314.000 Index in 14 Sep 2020 and a record low of 19.000 Index in 16 Jul 2021. United States AQI: Washington: Seattle-Tacoma-Bellevue data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

United States AQI: Connecticut: Worcester data was reported at 44.000 Index in 16 May 2025. This records an increase from the previous number of 34.000 Index for 15 May 2025. United States AQI: Connecticut: Worcester data is updated daily, averaging 39.000 Index from Jan 1980 (Median) to 16 May 2025, with 16573 observations. The data reached an all-time high of 154.000 Index in 22 Jul 2016 and a record low of 15.000 Index in 08 Oct 2018. United States AQI: Connecticut: Worcester data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]