Anthropogenic Carbon Nanotubes Found in the Airways of Parisian Children

• Fine particulate matters (PMs) were characterized in broncho-alveolar lavage fluids (BALF) from asthmatic children (n = 69).
• Anthropogenic carbon nanotubes were found in all samples, indicating that humans routinely breathe such nanostructures.
• Light microscopy cannot discriminate between PM and lamellar bodies, thus previous studies should be reconsidered.
• Fine particulate matters (PMs) from air pollution penetrate lower airways and are associated with adverse health effects even within concentrations below those recommended by the WHO. However, the most responsible components of the particulate mix are still unknown. We show that carbon nanotubes (CNTs) are present in the airways of asthmatic Parisian children. These nanostructures are similar to those present in dusts and vehicle exhausts collected in Paris, as well as to those previously observed in ambient air in the USA, in spider webs in India, and in ice core. These results suggest that humans are routinely exposed to CNTs.

Compelling evidence shows that fine particulate matters (PMs) from air pollution penetrate lower airways and are associated with adverse health effects even within concentrations below those recommended by the WHO. A paper reported a dose-dependent link between carbon content in alveolar macrophages (assessed only by optical microscopy) and the decline in lung function. However, to the best of our knowledge, PM had never been accurately characterized inside human lung cells and the most responsible components of the particulate mix are still unknown. On another hand carbon nanotubes (CNTs) from natural and anthropogenic sources might be an important component of PM in both indoor and outdoor air.We used high-resolution transmission electron microscopy and energy dispersive X-ray spectroscopy to characterize PM present in broncho-alveolar lavage-fluids (n = 64) and inside lung cells (n = 5 patients) of asthmatic children. We show that inhaled PM mostly consist of CNTs. These CNTs are present in all examined samples and they are similar to those we found in dusts and vehicle exhausts collected in Paris, as well as to those previously characterized in ambient air in the USA, in spider webs in India, and in ice core. These results strongly suggest that humans are routinely exposed to CNTs.

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