Experts consulted by the Einstein Agency explain that, on days with higher temperatures, superficial blood vessels dilate to release excess heat to the external environment, which can cause a drop in blood pressure, leading to malaise and even to fainting. Furthermore, in this situation the heart has to beat more frequently to maintain blood pressure, which can cause arrhythmia and heart failure in those who are already predisposed. Increased sweating on hotter days also makes the blood thicker, increasing the risk of blood clots, which can end up blocking the vessels.
“The kidneys also have to work harder in the heat to prevent the person from losing a large amount of fluid through sweating, and this can increase blood concentration and decrease urinary flow, leading to the risk of frequent urinary infections”, explains Saldiva .
Harms of pollution
Pollution, increasingly present in the atmosphere, harms the respiratory system, triggering or worsening illnesses such as asthma and obstructive pulmonary disease. The heart also suffers, becoming more susceptible to arrhythmias and cardiac arrests. Pollutants can also affect the female reproductive system, disrupting ovulation and putting fertility at risk.
Saldiva also highlights that the increase in temperatures and rainfall has an influence on infectious diseases, especially those caused by mosquitoes. “In the case of dengue, these factors increase the risk of larvae hatching, expanding the geographic borders of the disease, which was a coastal disease and is reaching the Central-West”, he explains. The doctor also draws attention to water-borne diseases, such as leptospirosis and enterovirus, which infect many more people due to floods.
For all these reasons, according to the World Health Organization (WHO), at least 150,000 people die annually as a result of climate change and this number is expected to double by 2030. “I believe this estimate is underestimated”, assesses the doctor at USP.
