• Lung transplantation
• BOS
• traffic pollution

To paraphrase the ubiquitous warning applied to the perverse products of the tobacco industry, ‘breathing may be dangerous to your health’, in particular if you are a lung transplant recipient. This is especially true if you live near a major road in a region with high levels of traffic-related air pollution. Alone among solid organ transplants, the lung allograft is exposed to the ambient environment with every breath. Some environments are toxic, some more so, and the paper by Nawrot et al in Thorax (see page 748) presents a compelling argument that traffic air pollution is a strong component of the toxic environmental risk which has measurable and deleterious effects on pulmonary allograft function and recipient survival, accounting for 28% of deaths.1 Specifically, this landmark study reports for the first time the relationship between traffic air pollution and the development of the bronchiolitis obliterans syndrome (BOS) in a large and well-characterised sample of lung transplant recipients from a region where air pollution levels are high by global standards. BOS is the major risk factor for death after lung transplantation, so it is not surprising that exposure to air traffic pollution, defined by residential proximity to a major road, was also a risk factor for death after transplantation. Importantly, other potential risk factors were rigorously examined to prevent confounding and the relationship was highly significant regardless of whether distance categories from a main road were expressed …