Primary aging derives from mechanisms inherent to our biology, such as the damaging mechanisms listed in the Strategies for Engineered Negligible Senescence (SENS) view of aging. Secondary aging derives from lifestyle choices (such as diet and exercise) and environmental exposures (such as particulate air pollution or persistent viral infections), harmful factors that can interact with the mechanisms of primary aging to accelerate the path to loss of function, age-related disease, and mortality. Epidemiological studies suggest that many people are losing at least a few years of life to poor choices, poor luck, or poor living circumstances.
Today's open access paper offers a high level tour of some of the major categories of environmental pollution. While extensive data indicates air pollution is harmful and increases the incidence of age-related diseases, data is somewhat lacking for many other areas of potential concern. Exposure to microplastic and nanoplastic particles, for example, may turn out to be as harmful as air pollution, but the few existing studies are by no means enough to say in certainty one way or another. Those studies can only collectively suggest that it would be wise to gather enough data to be sure.
Environmental Health Is Overlooked in Longevity Research
Environmental pollutants constitute an often-overlooked factor in the aging process. The mechanistic insights presented in this manuscript provide a snapshot of how specific classes of pollutants - including heavy metals, particulate matter, and endocrine-disrupting chemicals - induce oxidative stress through multiple pathways. These pollutants disrupt redox balance, impair mitochondrial function, and damage critical biomolecules such as DNA, proteins, and lipids, ultimately affects epigenetic aging. The cumulative impact of these events has significant implications for the overall trajectory of organismal aging. Epidemiological evidence linking pollutant exposure to cardiovascular, neurodegenerative, and oncologic outcomes further supports the concept that environmental health is an integral component of the longevity equation. In a recent study comparing genetic and environmental influences for 22 major diseases, polygenic risk scores explained less than 2 percentage points of additional mortality variation, whereas the exposome explained an additional 17 percentage points.
Environmental factors are estimated by the World Health Organization (WHO) to account for approximately 25% of the total burden of disease globally, which translates into a substantial loss of healthy life years on a population level. Using a back-of-the-envelope calculation based on WHO metrics, one can approximate that environmental exposures result in loss of several years of good health over the lifespan. This environmental burden is quantified using Disability-Adjusted Life Years (DALYs), which represent the total number of years lost due to ill health, disability, or premature death. WHO estimates that approximately 1.7 million DALYs are lost annually in France due to environmental factors.
To translate this population-level burden into an individual context, we can estimate annual per capita loss by dividing the annual 1.7 million DALYs by France's population of approximately 66 million which yields an average loss of about 0.0258 DALYs per person per year. Since one DALY equates to one lost year of healthy life, this corresponds to roughly 9.4 days of healthy life lost per person each year. Over an average lifespan of 80 years, this annual loss accumulates to approximately 2.1 years of healthy life lost per individual due to environmental exposures. This estimation reaches 3-4 years for the most polluted countries like China. This calculation does not take into account interindividual variations and it is likely that individuals who are exposed to pollution levels orders of magnitude higher than others will suffer in proportion.
View the full article at FightAging
