Cloud air pollution could affect your vision later in life, according to a major study that found a link between fine-grained air pollution and macular degeneration, an age-related eye disease that can lead to blind that cannot be changed.
The findings are a clear reminder of the many ways in which air pollution can harm our health, even though it is still early days for this research.
“Our findings add to the growing evidence on the devastating effects of environmental air pollution, even in setting low exposure to environmental air pollution,” the study’s authors say writing in their paper.
Air pollution is a global problem that few can escape, with the World Health Organization (WHO) estimating that more than 90 per cent of the world’s population lives in areas where air quality standards are falling. exceeding the limits set for pollutants that pose a health risk.
The biggest public health concerns about poor air quality revolve around pollutants such as pollutants (dust, soot, and more), ground-level ozone, nitrogen dioxide, sulfur dioxide and other gases, which emitted from motor vehicles, heavy industry, and wood fires.
Fine particles, called PM2.5 for a short time, particularly worrying. These microscopic particles smaller than 2.5 micrometres in size can penetrate deep into the lungs and enter the bloodstream, causing inflammation around the body.
Exposure to such pollutants can contaminate people’s eyes and throat, causing respiratory problems. In addition, environmental air pollution accounts for 43 percent of deaths from obstructive lung disease, and for more than a quarter of deaths from lung cancer, heart disease or stroke.
In this study, the focus was on age-related macular degeneration (AMD), a condition in which a person’s vision ages with age, leading to increased vision loss and even blindness.
The disease is associated with leaking blood vessels in the back of the eye and small blobs of fat and protein that build up on the macula, the part of the eye at the center of the retina. Genetics and smoking are among the main risk factors for this condition.
For their analysis, the researchers extracted data on thousands of people registered in Biobank UK and estimated the annual air pollution levels around their homes using other public databases.
From 2006, nearly 116,000 people were asked to report whether their doctor had diagnosed macular degeneration.
Of that larger group, 52,062 individuals ’vision and retinal thickness measurement were examined, as an indication of any changes in eye health.
The study found that people exposed to higher levels of fine air pollution had higher levels of self-reported AMD.
It was exposed to other pollutants, including nitrogen dioxide but not coarse with granular material, also associated with changes in retinal thickness, which were found on images.
But don’t worry about the large numbers alone. Very few people were diagnosed with AMD during the study – and remember, while this speculative study draws our attention to trends and patterns observed across populations, it cannot establish a cause.
In other words, researchers are doing what they can in population-wide studies like this to describe other factors, such as lifestyle, that affect the risk of disease but are sufficient say, trying to find out the exact health effects of air pollution in a world where not everything is always interconnected clearly cut.
The researchers suggest that air pollution can affect the eye in a circular way through inflammation and oxidative stress, two protective mechanisms where the body fights against foreign substances and attempt to detoxify chemical species, individually. But more research will be needed to examine that plausible link.
This is not the first time air pollution has been linked to eye disease. A 2019 study examining the global burden of glaucoma found that higher average levels of granulomas were associated with more cases of glaucoma, which affects the optic nerve.
“The good news is that environmental air pollution can be controlled and the diseases it causes prevented,” wrote Philip Landrigan, a public health physician and epidemiologist from the Icahn School of Medicine at Mount Sinai, New York. was involved in the study.
Implementing air quality standards and reducing emissions from coal-fired power plants – by switching to clean fuels and ultimately to renewable energy sources – would be both effective strategies for reduce air pollution.
We saw how quickly the skies were cleared in the first months of the coronavirus pandemic, which slowed down air traffic and dragged cars off the road as people lived at home. While these major changes were ultimately unsustainable, the huge relief from the air pollution that typically plagues cities has shown us what is possible.
“Cities and countries need to transition to unpolluted energy sources, encourage active travel, strengthen their transport networks, [and] redesigning business processes to eliminate waste, ”wrote Landrigan.
“These changes will not be easy. They must overcome a strong challenge with powerful protective interests. But, fortunately, the technical, institutional and policy tools needed to control air pollution are as- is available. “
In the meantime, more research will be needed to build the evidence around the long-term risks that air pollution poses to eye health.
The research was published in the British Journal of Ophthalmology.