Speaking to the Lusa News Agency, Ana Isabel Ribeiro, a researcher at the Porto institute and the first author of the work, explained that it aimed to “understand whether exposure to natural spaces had implications for the mental health of citizens”.

"Our hypothesis was whether those individuals who continued to be exposed to natural spaces could have better mental health in this period of public health crisis", she said.

The research, developed in partnership with the Institute of Environmental Science and Technology of the Autonomous University of Barcelona (ICTA-UAB), was published in the scientific journal Environment International.

“Despite being neighbours, Portugal and Spain had, in the first lockdown, different restrictive measures to combat the covid-19 pandemic”, said the researcher, recalling that Spanish citizens were deprived of using and attending public natural spaces.

In this sense, the researchers launched a questionnaire, which was available online between March and May 2020 and which covered issues such as frequency, type of exposure to natural spaces, type of housing, mental health, levels of stress, mental disturbance and psychosomatic symptoms.

The survey included 3,157 citizens aged 18 or over who remained in Spain or Portugal during lockdown, with 1,638 Portuguese and 1,519 Spanish from the total number of participants.

In both countries, there was a significant reduction in the use of public natural spaces such as beaches and gardens, and an increase in contact with private natural spaces, such as private gardens and urban gardens.

“We confirm our hypothesis. If in Portugal there is an important role in the frequency of natural spaces, in Spain the most important variables were exposure to private green spaces and to plants inside houses”, she said.