Association between Air Pollutant Emissions and Type 1 Diabetes Incidence in European Countries

Aims: The rise of Type 1 diabetes (T1D) incidence throughout Europe is only partially due to genetic factors, and the possibility that it may be affected by the amount of pollutant emissions has not been checked, until now.

Methodology: T1D incidence data among children from 16 European Countries (1990-2010) were collected (literature review) and analysed according to the nationwide amount of pollutant emissions (European Environmental Agency: particulate matter<10μm, PM10; nitrogen oxides, NOx; non-methane organic volatile compounds, VOCs; sulphur oxides, SOx; ammonia) in the same Nations/time periods. Pollutants were categorized by tertiles of emissions, and odds ratio (ORs) of T1D incidence were calculated.

Results: T1D incidence increased with time in all populations, and was positively correlated with the nationwide emissions of PM10 (P=0.03), NOx (P=0.0004), VOCs (P=0.009). Countries in the high tertile of PM10, NOx and VOCs emissions had higher ORs of T1D incidence than those in the low tertile, and mean T1D incidence was greater in Countries in the high- than in those in the medium or low tertile of PM10, NOx and VOCs emissions. T1D incidence was two-folds higher if two or more pollutants coexisted in the upper tertile of emissions.

Conclusion: The burden of specific pollutants might affect the extent of T1D incidence among European children, possibly triggering the development of disease by epigenetic mechanisms in genetically susceptible individuals. Thus, T1D might be considered, at least in part, a preventable condition. Further studies pointing to deeply explore this hypothesis are needed, also considering that primary prevention policies acting through a marked abatement of pollutant emissions might strongly attenuate T1D incidence throughout Europe.