Eye diseases and exhaust gas are related to air pollution?

Pollution rarely affects a person’s body immediately, but if left unattended, it slowly penetrates throughout the body. However, a study found that exposure to automobile exhaust gas may increase the risk of developing eye diseases that can lead to blindness.

The subject of this study is macular degeneration, a disease in which the macula, a part of the retina, is gradually destroyed. The macula is an indispensable organization to see clearly and upright what people want to see most. There are individual differences in the progression of macular degeneration, so even after several years, some people have little or no vision problems, but they also get worse quickly. It is not completely blind because the appearance other than the focus does not change, but it can be said to be a very annoying disease because you cannot see what you most want to see.

As with many degenerative diseases, there are many risk factors involved in developing macular degeneration. Age is also a big factor. It is also regarded as a major cause of irreversible vision loss in people over 50. It is also known to depend on heredity and environment. For example, the incidence of white Americans in the same age group over 50 is 2.1%, twice that of 0.9% of other races.

According to a paper published in the British Medical Journal (BMJ), few studies have investigated the relationship between air pollution and macular degeneration. However, several studies have proven that air pollution can increase the risk of eye diseases such as conjunctivitis and dry eye syndrome. It has also been found that smoking can double the risk of developing macular degeneration.

Based in China, the research team conducted an experiment comparing health data and air quality data. Specifically, it was verified for the incidence of macular degeneration over the age of 50 for 11 years from 1999 and the air pollution situation in the residence. For reference, there are various components in air quality, but in this experiment, attention was paid to a lot of nitrogen dioxide and carbon monoxide in automobile exhaust gas.

In addition, the subjects were divided into 4 groups according to the level of exposure to nitrogen dioxide and carbon monoxide based on the residential environment. In doing so, they found that people living in areas with the highest levels of nitrogen dioxide and carbon monoxide were almost twice as likely to diagnose macular degeneration than those living in areas with the least. The researchers say the study shows that exposure to air pollution is a risk factor for macular degeneration.

Of course, this study showed a correlation between air pollution and macular degeneration, but it did not indicate a causal relationship as to which one was the cause. In addition, factors such as age and high blood pressure were considered, but smoking history was not tracked. In addition, it should not be forgotten that the air pollution level in China is much higher than that of foreign countries such as the US. The findings may not be correct for all countries or regions, as we have not demonstrated that areas with low nitrogen dioxide and carbon monoxide emissions have a lower risk of macular degeneration. In addition, the risk of macular degeneration was only 0.036% of the 40,000 subjects.

Nevertheless, it is clear that China is one of the world’s largest countries with a population of more than 1.3 billion, and there are a number of countries with anxiety about severe air pollution. In addition, it is known that even in countries with relatively clean air such as reverse countries, thousands of people die every year from preventable diseases caused by automobile exhaust gas. Since the retina is directly connected to the central nervous system, there is a possibility that the brain may receive abnormal macular degeneration damage due to air pollution. Based on the same data as this study, in another paper published in 2018, it is known that exposure to contaminants increases the risk of developing dementia in the elderly. Related information can be found here .