Research points to a relationship between pollution and heart risks in residents of SP

Unpublished research shows that long-term exposure to air pollution is directly linked to increased heart risks in residents of the capital of São Paulo; for hypertensive individuals the danger is greater. Published in the journal Environmental Research, the study was carried out by researchers from the University of São Paulo (USP) with support from FAPESP.

The relationship between living in a polluted city like São Paulo and lung disease or cancer is already being studied and has been proven over the years. The problems, unfortunately, are not only related to lung diseases and cancer. Unpublished research shows that long-term exposure to air pollution is directly linked to increased heart risks in residents of the capital of São Paulo. For hypertensive individuals the danger is greater.

Published in the journal Environmental Research, the study was carried out by researchers from the University of São Paulo (USP) with support from FAPESP (projects 13/21728-2, 16/23129-7 and 19/06435-5). Research shows that cardiac fibrosis, an indicator of heart disease, is related to the length of exposure to black carbon particles, an indicator of air pollution.

The researchers analyzed the autopsies of 238 people and epidemiological data to measure this relationship. They also interviewed victims’ family members to gather information about risk factors, such as smoking history and high blood pressure. From macroscopic observation of the lung tissue, they established the presence and quantity of the black carbon fraction in the lungs. Myocardial samples revealed the fraction of cardiac fibrosis.

The results revealed a significant association between the fraction of black carbon in the lungs and cardiac fibrosis in the individuals studied. This means that the longer a person is exposed to pollution, the more likely they are to develop fibrosis. “This data highlights the crucial role of autopsy in investigating the effects of the urban environment and personal habits in determining diseases”, says one of the authors of the research, pathologist and professor at USP Paulo Saldiva.

Furthermore, it has been found that the risk is increased for hypertensive individuals. Among them, the presence of the heart disease marker increases with the increase in the presence of the pollution exposure indicator, both in smokers and non-smokers. Among non-hypertensive patients, the highest risks were observed mainly in smokers.

Hypertension, or high blood pressure, is a disease that can be silent and have no symptoms. According to the Ministry of Health, in ten years the mortality rate went from 11.8 deaths per 100 thousand inhabitants, in 2011, to 18.7 in 2021. Around 60% of elderly people living in Brazil have hypertension.

If hypertension is silent, pollution is not always so visible to everyone. In some cases, however, it is possible to know where it is most harmful. Exposure to pollution within the same city depends on factors such as people’s habits and movements. “We can say that there are two pollution indicators, one measured by the Cetesb network [Companhia Ambiental do Estado de São Paulo], which is objective. And another related to how much each individual is exposed to it,” he says. “In other words, the concentration level of environmental pollution does not mean the same dose received by everyone. If you’re in a traffic corridor for hours, you get a higher dose because the concentration in that environment is particularly higher.”

Saldiva explains that several factors, such as hypertension itself, influence the development of cardiac fibrosis and that it is now proven that pollution is one of them. “The question was ‘is the pollution big enough to appear in this photo?’ It has and it was the first time it was demonstrated in the world in humans. That’s the difference in work”, he points out.

According to the doctor, the study was only possible thanks to the work carried out by the Death Verification Service (SVO) in the city, 24 hours a day, 365 days a year. He states that the support of the USP Faculty of Medicine and FAPESP, in agreements established in the past with the SVO, built a vast set of processes and information that today result in new scientific possibilities.

USP research provides evidence on the impacts of air pollution on cardiovascular health and highlights the need for effective measures to reduce the population’s exposure to this evil. The implementation of measures such as reducing vehicle emissions, encouraging sustainable public transport in the city and encouraging clean energy sources are effective strategies in mitigating the impacts of air pollution on public health.

Source: Fapesp Research Magazine