Why an ERJ series on air pollution?

T he readers of the European Respiratory Journal are well aware of the importance of environmental exposures on the incidence and aggravation of several respiratory disorders, including asthma and chronic obstructive pulmonary disease (COPD), leading in some cases to mortality. Almost each month, one or more scientific articles deal with environmental lung diseases or with environmentally induced cardiovascular conditions (including ischaemic heart disease, heart failure and stroke), often in patients already affected by smokingrelated pulmonary diseases.