Air Pollution Exposure and Respiratory Diseases

The respiratory system, as the first point of contact with inhaled pollutants, is uniquely vulnerable and eventually reveals signs and symptoms if abnormal. Around 90% of the population worldwide breathes in the air with pollution, consisting of harmful or poisonous substances in outdoor or indoor air. The indoor air quality may be even more important than outdoor quality because of exposure time to pollution. Air pollution is the cause and aggravating factor of many respiratory diseases like chronic obstructive pulmonary disease (COPD), asthma, and lung cancer. In general, children and the elderly are considered more susceptible to air pollution effects than other groups. PM2.5 particulates and metallic elements are also known to contribute to health diseases. Both short-term and long-term exposure to air pollutants were associated with respiratory diseases. Individual exposures depend on many time- and location-specific impact factors, including pollutant type, pollutant concentration in the air, indoor sources, and second-hand smoke. In addition, many studies have shown that people can reduce their susceptibility to pollution through air filters, face masks, medical or chemoprevention methods. Recently, most multi-omics studies have focused on the relationship between environmental exposures and human health, assessing and measuring advances in DNA methylation, microRNA expression and proceeding in epigenetic regulation, protein expression, and metabolic effects. However, the results are still not fully established. Therefore, this special issue encourages potential authors to identify novel environmental risk factors, provide more evidence on the effects of harmful environmental exposures on respiratory diseases, and explore the underlying mechanisms between them, by collecting large samples of longitudinal cohorts, national-representative data, or well-conducting clinical trials. Laboratory, epidemiological and modeling studies on the effects of environmental exposure on respiratory diseases are also welcome. We aim to provide more evidence on the causal relationships between air pollution exposures and respiratory diseases.