2023-05-10 08:00:53
Air pollution, which is harmful to respiratory health, can also cause high blood pressure. According to a recent study, exposure to a mixture of air pollutants might cause repeated spikes in elevated blood pressure.
Air pollution: what impact on health?
Atmospheric pollution, commonly referred to as “air pollution”, refers to all emissions of polluting substances in the form of gases or particles into the atmosphere. These emissions are mainly the consequence of human industrial and agricultural activities.
To know ! Arterial hypertension is a chronic disease that affects 1 in 3 adults. Linked to abnormally high blood pressure in the blood vessels, it can cause cardiovascular or cerebrovascular complications.
In the past, studies have shown that certain polluting substances, taken in isolation, have an impact on blood pressure and can therefore promote hypertension. But so far, few studies have analyzed the combined effects of air pollution components on human health.
In this context, an international team of scientists wished decipher the effects on blood pressure of exposure in daily life to a mixture of five air pollutants:
- carbon soot
- Nitrogen dioxide (NO2)
- Nitric oxide (NO)
- Carbon monoxide (CO)
- Ozone (O3)
For this, the researchers recruited 221 participants from the “MobiliSense” study.
To know ! Conducted on residents of the Greater Paris metropolitan area, the “MobiliSense” study aims to explore the effects of exposure to air and noise pollution on cardiovascular and respiratory health.
Air pollution involved in high blood pressure?
To carry out their work, the scientists equipped each participant for a day with:
- A portable device measuring ambulatory blood pressure every 30 minutes.
- Two portable sensors continuously measuring the concentrations of pollutants in the ambient air near the breathing zone.
- A GPS plotter to follow the movements.
- An accelerometer for measuring physical activity and thus estimating respiratory rate (i.e. the volume of air inspired or expired per unit of time). .
The scientists then analyzed two models, the first taking into account the variations in the concentrations of pollutants in the ambient air, and the second taking into account the variations in the inhaled quantities of these pollutants. After collecting the measurements, the researchers were able to draw the following conclusions:
- Increase in systolic pressure when the concentrations of all pollutants increase within the mixture in the 5 minutes preceding the blood pressure measurement.
- Similar increase in systolic pressure when the quantity of inhaled pollutants increases in the 5 minutes preceding the measurement of blood pressure (linked to an increase in measured concentrations and/or physical activity and therefore respiratory flow).
- These associations remain weaker when exposure is observed over exposure windows longer than 5 minutes.
- The individual contribution to the effect of the mixture of pollutants on blood pressure is greater for ozone and black carbon.
These results show that an increase in the concentrations of airborne pollutants in the mixture studied leads to an immediate rise in blood pressure. For the lead author of this study, exposure to air pollutants in urban areas during travel and the repeated increases in blood pressure associated with it might thus contribute in the long term to a chronic rise in blood pressure.
The need to reduce the exposure of populations to air pollution
Although these results should be interpreted with caution given the few similar studies available, the authors stress the need to consider air pollution as a cause of hypertension. They thus encourage the implementation of measures aimed at reducing the exposure of populations to this daily pollution.
Next step for researchers? Decipher the physiological mechanisms involved in the rise in blood pressure linked to air pollution. There is no doubt that this future work will make it possible to better understand the link between air pollution and hypertension!
Déborah L., Doctor of Pharmacy
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#Pollution #arterial #hypertension
