Studies show that air pollution might be more harmful to people than previously realized

Posted: July 5, 2022 3:14 pm

Constant exposure to air pollution from living on a busy road can cause you to die early and it can severely damage your brain, according to findings in two new university studies.

The first study finds that one in every five people who breathe in polluted air—such as that found in residential areas close to busy roads—can die a premature death from heart attacks and strokes.

Another new study finds that inhaling contaminated air can cause inflammation of the brain as well as lead to brain disorders and neurological damage similar to Alzheimer’s disease in children as well as in older people.

Action urged

These findings have prompted medical researchers to urge more action to be taken by authorities to lessen the effects of air pollution on communities.

Doctors also are more likely to take into account the risks that the environment poses to their patients and to come up with ways in which they can lessen those risks, the researchers say.

Pollution leads to premature death

In the first study, conducted at New York University’s Grossman School of Medicine and the Icahn School of Medicine at Mount Sinai, researchers found that 20% of those people who were exposed to above-average amounts of air pollution were more likely to die over the following 14 years, largely from heart disease.

The research also found that, in addition to death, the rate of strokes and heart attacks themselves increased by 17% among those affected by the air pollution.

The study opens up the need for more action to be taken by authorities to mitigate the effects of air pollution on heart health in their communities, says Michael Hadley, a fellow in cardiology and assistant professor of medicine at Mount Sinai who was lead author of the study.

Conducted in Iran

The study was based on the experiences of 50,000 people over the age of 40 who live in the lower-income northeast Golestan region of Iran. The participants in the study were mostly poor and all agreed to their health being monitored during annual visits to the area by the researchers starting in 2004.

The region in Iran was chosen because traditional research conducted into environmental risk factors usually has favored big-city populations in countries with high national incomes that have a far greater access to modern health-care services. In the Golestan region most people live more than 50 miles from modern health facilities. They therefore lack access to clinics with catheterization laboratories that are able to unblock clogged arteries, for example, increasing their risk by 1% for every 6.2 miles of distance away from such facilities.

This study therefore adds additional needed scientific data for people who live in countries that are low and middle income, the researchers note.

Living close to busy roads

The study spotlights the role that living close to polluted and noisy roadways and the resulting air pollution plays in deaths from all causes and particularly from heart disease, says Dr Rajesh Vedanthan, senior author of the study and a cardiologist at New York University’s Langone Health. It also highlights the role that access to modern health services plays in such deaths, he adds.

Earlier studies have concluded a number of environmental factors contribute to premature death. They are: increased population density, low levels of income, and exposure to too much night-time light. The research team says, however, that this the study showed that these factors are not significant causes of premature death in the way that air pollution is.

The study therefore increases our understanding of which environmental factors might be the most damaging to heart health, Hadley explains.

The study is published in the journal PLOS ONE.

Toxic particles travel to the brain

The second study—conducted by a team of international experts from the University of Birmingham in England and institutions in China—found that when you breathe in polluted air the toxic particles travel directly from the lungs to the brain through the bloodstream. These polluted particles can cause brain damage and brain disorders, the study reveals.

Direct pathway

The scientists say they have found a direct pathway that the fine toxic particles take through the circulated blood. Once in the brain, the particles are hard to remove and stay there longer than they do in other organs.

The study sheds new light on the link between inhaled particles and how they move around a person’s body, notes Professor Iseult Lynch of the University of Birmingham. The data indicate that up to eight times the number of fine toxic particles might reach the brain by traveling through the bloodstream than pass through the nose, she explains. This adds new evidence to an understanding of the relationship between air pollution and the harmful effects toxic particles have on the brain.

The researchers also note that particles that are extremely fine are able to evade the protective systems of the body.

Recent evidence also has shown that there is a strong link between high levels of polluted air entering the body and marked inflammation of a person’s body tissue as well as changes in the brain that are similar to Alzheimer’s disease, the research team notes.

The study is published in the journal PNAS.

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