Researchers at University College London (UCL) found that even a low exposure to air pollution in England, Scotland and Wales appears to impact the risk of age-related macular degeneration (AMD).
AMD is the leading cause of irreversible blindness among people over 50 in high-income countries. AMD is linked to loss of central vision – necessary for reading, performing detailed tasks and recognizing faces – and the biggest risk factors for the disease are genetics, old age and smoking.
The team studied data from 115,954 people between the ages of 40 and 69 who participated in the UK Biobank, a large study of half a million people focusing on medical diagnostics and biological measurements of participants.
Using eye measurements and questionnaire data, experts studied those who said they had and did not have macular degeneration, and then compared the results with the amount of pollutants estimated at their home addresses.
“People who live in more polluted areas report macular degeneration more often,” Paul Foster, professor of glaucoma and ophthalmic epidemiology studies at UCL and senior author of the article, told CNN.
Foster said the main pollutants linked to macular degeneration are PM2.5 particles, nitrogen dioxide and nitrogen oxide.
PM2.5 are tiny pollution particles that can penetrate deep into the lungs when inhaled and enter the bloodstream. The particles, composed of dust, dirt, soot or smoke, originate from construction sites, unpaved roads, fields, chimneys or fires and can contain different chemicals. But most particles are a mix of pollutants from power plants, industrial emissions and vehicles.
Nitrogen oxides refer to nitric oxide gas and nitrogen dioxide gas, as well as other gaseous oxides containing nitrogen. The main source of these gases in urban areas is the exhaustion of motor vehicles, internal gas stoves and kerosene heaters.
Foster told CNN that pollutants enter the body through the lungs and appear to cause damage to the eyes due to the high blood flow in the eye wall.
“It is people breathing the substance, which goes into the lungs, is absorbed by the blood and carried by the blood,” he said.
“There is definitely a relationship between the most disadvantaged members of society and the greatest risk of contracting this condition,” he added.
Air pollution kills about seven million people worldwide each year, according to the World Health Organization (WHO), which claims that these deaths occur largely as a result of increased stroke mortality. , heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.
Chris Inglehearn, a professor of molecular ophthalmology at the University of Leeds, said the UCL research is similar to a 2019 study from Taiwan. “Both show a link between air pollution and age-related macular degeneration, a common cause of blindness in older people,” he told the Science Media Center.
“The profile of the pollutants that the two groups analyzed is a little different, but the source is the same, combustion. Of course, the correlation does not prove the cause, but the fact that these two independent studies reach similar conclusions gives greater confidence that that the connection they make is real, “said Inglehearn, who was not involved in the UCL study.
Inglehearn said that such studies “provide additional evidence that links air pollution with harmful impacts on human health”.