• Viral respiratory infections are a typical cause of asthma attacks, which involve a worsening of the inflammation and a narrowing of the bronchial airways. Nevertheless, non-viral causes of asthma attacks are also possible.
• Greater exposure to air pollutants is linked to a higher risk of asthma attacks, although it is unclear how air pollutants work at the molecular level to start asthma attacks.
• A recent study found that children living in metropolitan areas were more likely to experience asthma attacks with exposure to greater levels of air pollutants, specifically ozone and fine particle matter.

Although respiratory infections caused by viruses are the most common cause of asthma episodes, non-viral variables including air pollution have also been linked to the exacerbation of asthma symptoms.

According to a new study

According to a Reliable Source that was recently published in the journal Lancet Planetary Health, higher levels of air pollution, in particular concentrations of ozone and fine particulate matter, were associated with an increase in the number of asthma attacks and a decrease in the amount of lung function in children who lived in urban centres.

Researchers also noticed that asthma attacks might be triggered by these air pollutants even when their concentrations were below the national criteria for the quality of the air we breathe.

The researchers also found that higher concentrations of ozone and fine particulate matter were associated with the activation of specific inflammatory pathways in the airways. This finding contributed to the researcher's understanding of how higher pollutant levels may lead to an increased risk of asthma attacks in children who live in urban areas.

According to Dr Antonella Zanobetti, an environmental health researcher who works at the Harvard T.H. Chan School of Public Health in Boston, "I think that this paper is very interesting and important because they were able to look at asthma exacerbation as well as have data on the absence of respiratory virus and examine other outcomes." "I think that this paper is very interesting and important because they were able to look at asthma exacerbation as well as have data on the absence of respiratory virus and examine other

Therefore, air pollution in this study was a trigger of asthma exacerbations independently of respiratory viral infections, which in turn is important to understand the biological mechanisms, he told Medical News Today. "They show an association between air pollution and asthma exacerbations occurring in the absence of a provoking respiratory virus," he said. "This in turn is important to understand because it relates to the biological mechanisms."

"Their study went much further than many other studies in that they carefully analysed the relationship between air pollution and asthma exacerbations regardless of whether these events occurred during viral infections or not," added Dr Allen Dozor, a professor of paediatrics and division chief of Pulmonology at New York Medical College. "Their study went much further than many other studies in that they carefully analysed the relationship between air pollution and asthma exacerbations regardless of whether these events occurred during viral infections or not."

According to an interview he gave with Medical News Today, "Viral infections are extremely common in children, and the majority of severe asthma attacks are connected with upper respiratory tract infections (URIs) or colds." "Each year, an unbelievable number of children suffer from the common cold; nevertheless, for many children, particularly those who live in locations with high levels of air pollution, colds frequently progress to serious asthma attacks. It is essential to underline that high levels of air pollution make asthma episodes worse, regardless of whether they are caused by a virus or something else.

What you need to know about asthma attacks

A chronic disorder known as asthma is characterised by inflammation and narrowing of the main airways in the lungs, known as the bronchi, as well as the smaller airways that branch out from them.

Symptoms of asthma include chest tightness, shortness of breath, coughing, and wheezing; these symptoms tend to get worse when an asthma exacerbation is present.

An exacerbation of asthma, also known as an asthma attack, is characterised by a greater constriction of the bronchial muscles and inflammation of the cells that line the airways of the lungs. This results in a narrowing of the airways in the lungs. In addition to this, an excessive amount of mucus will be produced, which will further contribute to the congestion of the airways.

Exacerbations of asthma can be brought on by a variety of factors, but one of the most prevalent of these factors is an infection of the respiratory tract caused by a virus. On the other hand, aggravation of asthma can also be brought on by non-viral factors, such as infections that aren't caused by viruses, allergens, pollen, or the hair of pets.

In addition, several epidemiological research has demonstrated a correlation between the levels of air pollutants and the incidence of asthma attacksReliable Source. Increased concentrations of several contaminants in the air, including fine particulate matter, ozone, nitrogen dioxide, and sulphur dioxide, have been associated with an increased risk of asthma episodes.

One of the chronic illnesses that affect children at the highest rate is asthma. In addition, research has shown that the incidence and prevalence of asthma are significantly higher among children who live in urban districts with lower socioeconomic status. The higher levels of air pollution that are typical of these neighbourhoods may help to explain why children living in low-income urban regions have a higher prevalence and severity of asthma than children living in other metropolitan areas.

Yet, the molecular pathways that are responsible for an asthma exacerbation during a respiratory infection that is not caused by a virus are not well known, particularly in sensitive populations such as children who have severe asthma. In addition, the variations in the mechanisms that underlie asthma exacerbations induced owing to air pollution and viral infections have not been described. This is even though both of these causes are known to exacerbate asthma symptoms.

Influence that air contaminants have on asthma sufferers.

The investigators of the recently published study began by looking into whether or not there is a correlation between the levels of air pollutants and the severity of asthma attacks in children and adolescents who live in urban areas.

The researchers looked at the results of an earlier observational study that they had done.

Authoritative Reference with the following title: "Mechanisms Underlying Asthma Exacerbations Prevented and Persistent with Immune-based Treatment Part 1 (MUPPITS1)"

The authors of that study had used data from MUPPITS1 in a prior investigation in which they investigated the molecular pathways driving both viral and non-viral asthma exacerbations.

The current research was conducted to use the MUPPITS1 data to precisely gain an understanding of the molecular basis of non-viral asthma exacerbations caused due to air pollution.

208 children with asthma who were between the ages of 6 and 17 and who lived in low-income communities in nine different cities across the United States participated in the MUPPITS1 study. Following the commencement of symptoms associated with an episode of respiratory disease, the participants in the study provided data on their lung function as well as samples from their nasal passages.

The nasal samples were analysed by the researchers to identify whether the respiratory disease was brought on by a viral infection or whether it was brought on by factors other than viruses. They also categorised the participants further based on whether or not they had an asthma exacerbation when they were sick. Those who did not experience an asthma exacerbation were considered healthy.

The researchers then made use of data on the Air Quality Index as well as the concentrations of particular pollutants that were gathered by the Environmental Protection Agency (EPA) for each geographical location that was a part of the study. These data on air pollution were matched with the location of each participant as well as the day they became unwell.

According to the findings of the study, participants who had an asthma exacerbation that was not caused by a virus had Air Quality Index values that were higher nine days before and after the onset of symptoms. This was in comparison to participants who had an asthma exacerbation that was caused by a virus. In addition, the values of the Air Quality Index had a negative correlation with lung function in the participants who had an aggravation of their asthma that was not caused by a virus.

Using data from a separate study comprising 419 people aged between 6 and 20 years who resided in low-income families in eight major cities in the United States, a similar link between the Air Quality Index and non-viral asthma exacerbations was also detected.

According to the findings of both investigations, the levels of ozone and fine particulate matter (PM2.5) were significantly greater during bouts of asthma exacerbation that were not caused by a virus. Moreover, there was a correlation between higher ozone concentrations and decreased lung function.

The readings of the Air Quality Index, as well as the amounts of ozone, did not exceed the national limits for air quality. Only in a few of the samples were the quantities of fine particulate matter found to be higher than the typical ambient values.

According to the authors of the study, this could imply that being exposed to low amounts of air pollution over numerous days could be sufficient to trigger an asthma attack. In addition to this, they mentioned that the regional EPA estimates might not accurately reflect the high amounts of these contaminants that are found in certain urban areas. Also, an individual's unique exposure to air contaminants might differ, even among people who live in the same place.

Gene expression profile

Then, the researchers used the nasal samples obtained from the MUPPITS1 investigation to investigate the changes in gene expression.

The association between the Air Quality Index and shared gene expression patterns in viral and non-viral asthma exacerbations suggests the presence of core pathways that are responsible for asthma attacks. In addition, the values of the Air Quality Index were shown to be associated with alterations in the gene expression profile that was unique to asthma exacerbations that were not caused by viruses.

Fine particulate matter levels were specifically correlated with an increase in the expression of genes associated with excessive mucus secretion and proinflammatory cytokines, which are a class of signalling proteins, in non-viral asthma exacerbations. This correlation was found at the level of individual air pollutants.

Also, a positive correlation was found between the levels of fine particulate matter and the expression of tissue kallikreins, which are a set of enzymes that are involved in inflammation and are found at higher levels in asthma patients.

The epithelial cells line the majority of the respiratory tract, providing protection against pathogenic agents, allergens, and debris that are inhaled and that have the potential to cause damage to the respiratory system. In addition, the levels of fine particulate matter were related to the expression of genes that are involved in the barrier function of epithelial cells.

There was a correlation found between the concentration of ozone and genes linked with type-2 inflammation in people who had non-viral asthma exacerbations. Type-2 inflammation is a form of inflammatory response that is commonly seen in asthma patients.

Attempting to locate solutions for asthma.

According to the findings of a recent study, the greater frequency and morbidity of asthma in children living in urban areas could be explained by the molecular pathways that are involved in asthma aggravation and are connected with certain air pollutants.

It is possible that the identification of molecular pathways that are specific to asthma exacerbations brought on by increased levels of air pollution would help in the development of therapies that target these molecular pathways.

In addition, the use of portable gadgets that help monitor air quality levels as well as air filters during high levels of air pollution may help reduce the risk of asthma exacerbations that are caused by pollution.

The authors were careful to point out that the study was observational and did not show a causal relationship between the presence of air pollution and the frequency of asthma exacerbations.

In addition, Zanobetti remarked that "the study employed air pollution from monitors and only had a limited number of participants." In addition, they investigated the level of air pollution in the days leading up to the event, which indicates that they concentrated on the short-term consequences rather than the long-term ones. Thus, there is a need for additional research, which should include more data and a higher resolution of the air's spatial contamination.