Long-term exposure to air pollution increases the risk of asthma in children and adults

Long-term exposure to PM2.5 pollution significantly increases the risk of asthma for children and adults, contributing to approximately 30% of global asthma cases.

Study: Long-term exposure to PM2,5 has significant adverse effects on childhood and adult asthma: A global meta-analysis and health impact assessment. Image credit: Shutterstock AI/Shutterstock.com

In a recent study published in An Earthresearchers review the existing evidence on the effects of long-term exposure to fine particulate air pollution on the risk of developing asthma.

Global burden of asthma

Over 250 million people worldwide live with asthma today, with symptoms such as wheezing and coughing that can seriously affect an affected person’s quality of life and, in severe cases, be life-threatening. Asthma management requires ongoing medication and healthcare, thus creating financial strain on individuals and society.

Exposure to particulate matter 2.5 microns or smaller in diameter (PM_2.5) for long periods is a potential risk factor for asthma. However, previous studies on this association have shown inconsistent results. Furthermore, many of these studies have been conducted in high-income countries, thus limiting their generalizability to other regions of the world.

Additional research is needed to clarify the relationship between asthma and PM_2.5as air pollution is a modifiable risk factor. Findings about this association could also support the development of policies and personal actions that can reduce exposure.

Linking asthma to air pollution

In the current study, researchers conducted a systematic review of long-term PM_2.5 exposure and asthma risk in 1,027 records obtained from studies involving over 25 million participants in 22 countries.

Meta-response and exposure analyzes were performed to assess the impact of PMs_2.5 exposure to asthma risk. Asthma-related health burdens due to PM_2.5 Exposure was calculated and compared with burdens from other PM-related diseases_2.5such as lung cancer.

The initial review identified 3,406 studies, of which 41 looked at childhood asthma and 18 looked at adult asthma. The included studies represented a broad global PM_2.5 report, with over 90% of the world’s population accounted for.

Increase PM_2.5 Concentrations of 10 µg/m³ were associated with a 21.4% increase in all types of childhood asthma and a 7.1% increase in adult asthma. Greater risk of asthma was associated with PM exposure_2.5 in early life, with this risk increasing with age. However, large variability was observed between studies, which the researchers attributed to different methods used to assess exposure and to different PM compositions._2.5.

Policy implications

The prevalence of asthma has increased significantly worldwide since the 21st century^St century, particularly in low- and middle-income countries. About 4% of the world’s population has asthma, with 30 million new cases diagnosed each year.

In the current study, the researchers found evidence for a linear relationship between PMs_2.5 levels and risk of asthma. In 2019, approximately one in three asthma cases worldwide was linked to PM_2.5 report.

Children are at greater risk of developing asthma from PM_2.5 exposure, which may be due to a higher sensitivity associated with age. Currently, there is limited evidence on the effects of PM_2.5 exposure to asthma mortality, as most studies have focused on asthma prevalence and incidence.

Every PM_2.5 component affects asthma differently. for example, organic matter and black carbon have stronger effects than inorganic particles. Other pollutants are often associated with PM_2.5; However, adjusting for these pollutants does not significantly affect the association between PMs_2.5 and asthma.

Overall, the study findings highlight the importance of reducing air pollution, particularly PM_2.5to reduce the risk of asthma in adults and children worldwide. Stricter air quality legislation could reduce the burden of asthma and significantly improve public health.

Strengths and limitations

Notable limitations of the current study include various methods used to measure PM_2.5with inaccuracies that could lead to biased risk estimates. Future studies using high-resolution data could improve the accuracy of these measurements. The heterogeneity between different studies also highlights the need to standardize PM measurement methods_2.5 exposure and diagnosis of asthma.

Some strengths of the current study include its large and geographically diverse sample, as well as the use of rigorous data criteria to minimize bias and enhance the robustness of the results. However, there is still a lack of high-quality longitudinal studies conducted in low- and middle-income countries.

conclusions

The researchers of the current study performed a comprehensive global meta-analysis of more than 25 million people, including data from low- and middle-income countries. Here, long term PM_2.5 Exposure was found to significantly increase the risk of asthma for both adults and children.

Our findings highlight the urgent need for policy makers to enforce strict legislation to continuously combat air pollution, while personal maneuvers, such as wearing a mask, can also help reduce individual exposure and mitigate the risk of asthma.”