Pollution and sudden drop in temperature test the health of São Paulo residents

The sudden change in temperature and air pollution aggravated by dry weather should once again challenge the health of residents of the capital of São Paulo.

While on Friday (9) São Paulo had a day with a temperature above 33°C and humidity below 20%, according to Inmet (National Institute of Meteorology), this weekend the temperature should drop to 12°C, changing the behavior of the organism.

The doctor Olavo Mion, a member of the allergy department of ABORL-CCF (Brazilian Association of Otorhinolaryngology and Cervico-Facial Surgery), explains that for the nose to properly perform the functions of heating, humidifying and filtering the air, the ideal is that the environment is already warmer, cleaner and humid. When the condition is not suitable – cold, dry and more polluted days – the task of the nose becomes more challenging and the entire respiratory system suffers together.

On these days, the body produces mucus as a way to humidify the air before it reaches the lungs and, with the cold, it is natural for the system to close to prevent heat loss. The result of this is accumulation of secretion.

“Throughout the day, we come into contact with different airs, which can be good or bad, and the mucosa will react accordingly. The person says: ‘But yesterday I was fine’. But today’s air is not the same yesterday”, says Mion.

To make matters worse, this aggression can lead to inflammation such as the famous rhinitis, making breathing difficult. The air begins to be pulled through the mouth, which does not have the ability to filter the nose, enters the most polluted, dry and cold body, irritates the throat and favors the emergence of problems such as pharyngitis.

“Our systems need time to adjust. Sudden changes in temperature are very large aggressions. And how does the body respond to aggressions? Inflammation”, explains the otolaryngologist.

Inflammation in the lung, in turn, is related to increased mucus and contraction of the bronchi, making it difficult for air to pass, says pulmonologist Patricia Canto, coordinator of the SBPT (Brazilian Society of Pulmonology and Occupational Respiratory Diseases) Commission. Physiology). All this with pollutants and different viruses and bacteria in the environment, which tends to be more closed with low temperatures.

Those most affected by this unfavorable set, says Canto, are children under five, the elderly and immunocompromised patients. Children’s airways are smaller in size and their immune systems are not yet fully developed, whereas people over 60 years of age have reduced immunity and a loss in the ability to regulate temperature.

Simone Fiebrantz, president of the department of gerontology at the SBGG (Brazilian Society of Geriatrics and Gerontology), says that it is common, for example, for the elderly to wear heavy clothes even on hotter days, which increases the risk of dehydration, or to keep their very icy extremities on cold days.

“If you are a person with diabetes and compromised peripheral circulation, this can cause small necrosis on the fingertips. There are also elderly people who place a hot water bottle next to their body and, due to the loss of sensitivity, they end up with a burn. “, alert.

She also recommends paying attention to frequent complaints on cold days. There is a tendency for the body to contract to prevent heat loss, and muscle contraction can cause discomfort. In addition, elderly people with prostheses may experience greater discomfort. To lessen the problem, she suggests compresses, a hot water or seed bag in place, and gloves, socks and a cap to reduce heat loss.

Another more susceptible group is patients with a history of lung or heart problems. A study published in 2019 in the journal Scientific Reports, by the group Nature, calculates 661 annual deaths from heart attacks in São Paulo attributed to low temperatures.

“In the cold, blood vessels are more inflamed and the individual is more likely to have thrombosis, which is a mechanism of infarction”, says João Fernando Monteiro Ferreira, chairman of the board of directors of the SBC (Brazilian Society of Cardiology).

Additionally, the cold can lead to an increase in blood pressure, which contributes to cardiovascular events, and the situation worsens if there is pollution in addition to the low temperature.

“We have studies from the Experimental Atmospheric Pollution Laboratory of the USP School of Medicine showing that, in peaks of atmospheric pollution, attendances for arrhythmia, angina and heart attack increase. This happens because the finer particles are inhaled, reach the alveoli, pass to bloodstream and cause inflammation of the vessels”, explains pulmonologist and researcher José Eduardo Cançado.

He also enumerates the chronic effects of pollution, such as damage to the lung development of children and adolescents and an increased risk of cancer, in this case because the microparticles that pass into the bloodstream can lead to changes in the DNA of cells.

“There is no safe level of atmospheric pollution, and it is very important to work to reduce all sources, including fires and pollution from vehicles and industries. We do not see, for example, policies aimed at improving public transport”, criticizes Cançado.