Sensitive areas are associated with fewer deaths due to Covid-19, an observational study indicates.
Increased exposure to the sun’s rays – specifically UVA – could serve as a simple intervention for public health if further investigation determines that it causes a decrease in mortality rates, experts say.
Researchers from the University of Edinburgh compare all recorded deaths from Covid-19 in the continental US from January to April 2020 with UV levels for 2,474 US provinces for the same period.
The study found that people living in areas with the highest exposure to UVA rays – which make up 95 percent of the sun’s UV light – have a lower risk of dying from Covid-19 compared to those with a lower level. The analysis was repeated in England and Italy with the same results.
The researchers took into account factors associated with increased exposure to the virus and the risk of death, such as age, ethnicity, socioeconomic status, population density, air pollution, temperature and levels of infection in local areas.
The experts said that the observed reduction in the risk of death due to Covid-19 could not be explained by higher levels of vitamin D. Only areas, with insufficient UVB levels to produce a significant amount of vitamin D in the body, were included in the study.
One explanation for the lower number of deaths, which the researchers follow, is that exposure to sunlight causes the skin to release nitric oxide. This may reduce the recurrence of SARS Coronavirus2 – the cause of Covid-19 – as found in some laboratory studies.
Previous research from the same group has shown that increased exposure to sunlight is associated with improved cardiovascular health, with lower blood pressure and fewer heart attacks. Since heart disease is a known risk factor for dying from Covid-19, it may also explain the latest findings.
The team says that due to the observation of the study, it is not possible to determine cause and effect. However, it can lead to interventions that can be tested as possible treatments.
The paper is in the British Journal of Dermatology, an official publication of the British Association of Dermatologists.
Reference: April 8, 2021, British Journal of Dermatology.
DOI: 10.1111 / bjd.20093
Dr. Richard Weller, corresponding author, consultant dermatologist and Reader at the University of Edinburgh, said: ‘There is still so much we do not understand about Covid-19, which has resulted in so many deaths worldwide. These early results provide exposure to sunlight as one way to potentially reduce the risk of death. ”
Professor Chris Dibben, chair of health geography at the University of Edinburgh and co-author, said: “The link between Covid-19 mortality, season and latitude was quite striking. Here we offer an alternative explanation for this phenomenon.”