Fig. 1
From: Desert dust outbreaks and respiratory morbidity in Athens, Greece
Directed acyclic graph for the suggested associations between desert dust events, PM10 levels and respiratory morbidity. According to the suggested underlying mechanisms, particulate matter has a direct effect on respiratory morbidity. Dust events contribute to the levels of particulate matter and thus affect respiratory morbidity but may also have an effect on respiratory morbidity by other mechanisms independent of the levels of particulate matter