Table 2.

Consequences of outdoor air pollution over allergic rhinitis and asthma (adapted from Eguiluz-Gracia et al. [22])

Environmental factors	Health outcomes
Pollution from traffic and industry (PM10, PM2.5, NO, NO2)
During childhood	Higher asthma prevalence after the school age
During adulthood	Possibly higher asthma prevalence
Lifelong	Poorer lung function Higher rate of asthma exacerbations Conflicting results on AR onset
Livestock farming (organic dust, toxins form microorganisms, gases like ammonia and methane)	Decreased lung function
Black carbon	Possibly epigenetic changes leading to increased type two inflammation in children
Interaction between air pollutants (PM10, nitrogen oxides) and allergens (pollen, fungal spores)
Production of more pollen, more allergens per pollen grain, and more PALMs per pollen grain	Potentially, facilitation of IgE sensitization against aeroallergens Higher rate of asthma-related hospitalizations