IMM thesis: Impact of air pollution exposure in children and young adults

This thesis focuses on elucidating the biological mechanisms behind the negative health effects of air pollution exposure in children and young adults. We aimed to explore how air pollution exposure during different periods of life impairs respiratory health from childhood to young adulthood, with a particular emphasis on systemic inflammation and metabolic dysregulation. Our research utilized advanced tools of proteomics and metabolomics to investigate these mechanisms, which were previously not well understood in epidemiological studies. The thesis comprises four studies based on Swedish birth cohorts, examining the relationships between air pollution exposure, inflammation-related proteins, urinary metabolites, and lung function. We employed a comprehensive approach, analyzing time-weighted average exposure to air pollutants estimated using validated dispersion models, and exploring their associations with a wide range of biomarkers and lung functions across different life stages. 

Can you tell us about some interesting results?

We observed that early-life air pollution exposure was longitudinally associated with inflammation-related proteins during early childhood, in an age and sex-specific manner. Further, we found that early life air pollution exposure and altered inflammation-related protein profiles interact synergistically towards lower lung function at the age of 6 months.

Both early life and recent air pollution exposures were associated with urinary metabolic profiles in children and young adults. In particular, air pollution was associated with upregulated caffeine metabolism in children, likely due to increased enzyme activity. Our data suggests that the carnitine profile in the pathway of oxidation of fatty acids may modify the air pollution exposure – lung function association.

Importantly, we found that molecular changes related to air pollution exposure can be detected even in environments with relatively low exposure levels, such as Stockholm County. This highlights the public health importance of further reducing urban air pollution levels.

What further research is needed in the area?

Future research directions should focus on larger sample sizes, causal mediation analyses incorporating genomic data, and exploration of potential interventions for deviating inflammation-related profile and metabolic imbalances in vulnerable populations. These studies lay the groundwork for more comprehensive investigations into the long-term health impacts of air pollution exposure, particularly during critical developmental periods.