Perceived air pollution in Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa, USA before and during COVID-19 restrictions
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.