LongITools study investigates the ways air pollution can harm our health

Air pollution is an additional risk factor for several health conditions, including heart disease, strokes and dementia (indeed, other LongITools papers have investigated these links). However, the specific molecular mechanisms – why air pollution makes us ill exactly – remain only partially understood.

A LongITools study, published in Environmental Research, has tackled the question head-on. Researchers from Erasmus MC discovered clear associations between air pollution and its impact on several metabolites (small particles used by our bodies to function in various ways), particularly in older individuals. This could be one of the ways our bodies reacts when facing long-term exposure to pollutants, potentially explaining the way some chronic diseases develop.

Methods

The study used data from over 2,500 adults between 51 and 99 years old in two cohorts of the Rotterdam Study, a long-running population study in the Netherlands. Sub groups,  sub-cohort 1 (average age 77) and sub-cohort 3 (average age 63), were used in this study.

The research focused on the metabolites found in an individual’s plasma, a component of their blood. Metabolites – small molecules within cells, biofluids, tissues or organisms – are made when the body breaks down food, drugs, chemicals, or its own tissue. Collectively, these small molecules and their interactions within the body are known as the metabolome. They are critical in our overall health and how well the body functions.

Researchers estimated air pollution levels by cross-referencing their address with advanced ‘land use regression models’, a type of method for estimating pollution levels in an area. They looked at a variety of pollutants, including black carbon, nitrogen dioxide and ozone.

Using these two metrics, the research team could track how levels of pollution affected an individuals’ metabolome.

Findings

In both cohorts, researchers found associations between air pollution and a wide range of metabolites found in plasma. But only in sub-cohort 1, with an older average age, were the changes consistent and pronounced enough to attempt further unravelling potential disease mechanisms. In this process, two systems were found to be involved – steroid hormone biosynthesis (how our body creates sex and stress hormones), and pyrimidine metabolism (how the body deals with a compound called pyrimidine, a crucial component of DNA). Both are essential to many structures and functions of our bodies, so disruptions to these systems may explain why air pollution has been linked to a wide range of conditions.

What does this mean?

This research helps build a much clearer picture of how our wider environmental exposures (our ‘exposome’) can directly influence our health. This study has identified two potential pathways through which air pollution can damage our health, and, as such, adds to our knowledge about the biological pathways between air pollution and chronic diseases. This could help develop treatments or inform policies linked to safe pollution levels in the future.

The study highlights the need for more research into how air pollution can affect vulnerable groups, particularly the elderly. Unveiling the molecular mechanics behind air pollution could go a long way in helping to understand what remains a major, global health concern.

Paper

Bigina N.R. Ginos et al. Long-term air pollution exposure and the blood metabolome: The Rotterdam Study. Environmental Research (2024). 263(2), 120131.