Health : Air pollution and its link to brain cancer and other health problems
Air pollution can damage the lungs and we all know it, but for the first time new scientific research shows a direct link between pollution and brain cancer. When exposed to ultra fine particles in the air produced by the combustion of fuel, especially diesel vehicles, there is a high chance of developing fatal cancer. Previous scientific research has already shown that nanoparticles can enter the brain and can carry cancer-causing chemicals.
Brain cancers are rare and scientists have calculated that an increase in air pollution and frequent exposure such as moving from a small town to a big city leads to a greater chance of having a brain cancer for every 100,000 people exposed.
Air pollution could cause brain cancer
According to Scott Weichental of McGill University in Canada who conducted the research, environmental risks such as air pollution are not of great magnitude – their importance comes from the fact that all people of people are exposed to it. So when the small risks are multiplied by many people, the risk increases sharply. In a big city, the number of cancers due to pollution can be large, since these tumors are often fatal.
Scientific research has analyzed the medical data and the pollution exposure of 1.9 million adults in Canada from 1991 to 2016. Such a large scientific study gives very strong evidence but not an occasional link. Weichenthal says the correlation seen between brain cancer and nanoparticles was very strong, but since this is a first scientific study, it is important that other scientists replicate it.
Nanoparticles in the air can be carcinogenic
The discovery of abundant toxic nanoparticles of air pollution in human brains was made in 2016. A comprehensive global review earlier in 2019 concluded that air pollution can damage any organ and virtually all cells in the human body. Toxic air has been linked to other effects on the brain including large reductions in intelligence, dementia and mental health issues in children and adults. The World Health Organization confirms that air pollution is a public health emergency.
Air pollution in large cities is significant
New study published in the journal 'Epidemiology' finds that an increase of 10,000 nanoparticles in air pollution for a year, the average difference between a quiet city and a big city increases the risk of having brain cancer more than 10%.
Pollution levels in the cities studied, Toronto and Montreal, were between 6,000 / cm3 and 97,000 / cm3. Weichenthal says people living with 50,000 / cm3 pollution are 50% more likely to have brain cancer than people living with 15,000 / cm3 pollution. The cities Toronto and Montreal are typical large cities and the nanoparticles found there are the same as those in other major cities in the world. The researchers' analysis took into account factors such as income, smoking and obesity levels and whether people have changed their homes.
Scientists do not know much about the causes of brain tumors, so all the environmental factors they can identify help to deepen their understanding. Dr. Weichenthal's team had more recent air pollution data and assumed a difference between different streets and neighborhoods in the past.
Professor Jordi Sunyer of the Institute of World Health in Spain who was not involved in the scientific study believes that the result is very important since nanoparticles are directly emitted by the combustion of vehicles. Several scientific studies with animals have shown that nanoparticles are more toxic than large particles in the air.
Professor Barbara Maher at Lancaster University in the UK says that iron-rich nanoparticles from traffic pollution are carcinogenic and are a plausible cause of brain tumor. She also says that nanoparticles are not regulated and are rarely even measured.
Scientists advise avoiding polluted streets when walking or cycling. It is always a good idea to reduce your exposure to pollution. But the most important actions are at the regulatory level where action can be taken to reduce everyone's exposure to pollution.
But in addition to increasing the risk of developing brain cancer, air pollution can also change the way we think, scientists say. A study published in ‘Proceeding for the National Academy of Science’ finds that long-term exposure to sulfur dioxide and nitrogen dioxide leads to cognitive decline in participants with age. Less educated men were particularly struck and had very poor verbal and mathematical results.
Scientists are still studying how air pollution interacts with the brain. They think that air pollution can seriously damage white matter in the brain which is associated with language skills. Previous studies have already shown that female brains on average contain more white matter than male brains. This means that impacts on white matter will put men with less white matter at greater risk of cognitive decline. But more research is needed to understand the exact mechanisms.
While a Chinese study highlights an important link, research will need to be replicated to demonstrate how air pollution changes the brain. Pollution and brain research has only been going on for decades, and more time will be needed to clarify the matter.
Polluted particles can pass along olfactory nerves from the nose to the brain or they can enter the blood, researchers say. They also believe that damage can also be caused by inflammation. And in addition to the lungs and the brain, scientific studies have also linked air pollution to cardiovascular problems and diabetes.
It is surprising how many organs can be affected by air pollution. The reason for this is the fact that the organs of the human body are very related to each other. Pollution affects not only the lungs, but also the brain, the heart and the reproductive system. When toxic particles enter the body, the damage will be to all organs.
All of the blood from the lungs goes to the heart where it is then sent to the rest of the body. This causes the immune system to cause inflammation. Over time, too many toxic particles can cause too much inflammation, which can accelerate brain aging. The brain is a difficult organ to study because of the many variables that can change brain chemistry. So we just have to try to avoid air pollution and do everything we can to reduce it.