The Hidden Costs of Noise Pollution

The Hidden Costs of Noise Pollution

Noise is the pollutant that hides in plain hearing. Unlike smog or contaminated water, it leaves no visible residue, and its health effects accumulate so gradually that they are easy to dismiss as the ordinary stress of modern life. Yet the epidemiological evidence is now difficult to ignore. A landmark study published in The Lancet estimated that chronic exposure to traffic noise above 55 decibels is associated with a measurable increase in cardiovascular risk, independent of air pollution. The mechanism appears to involve the body's stress-response system: even during sleep, the auditory cortex continues to process environmental sound, triggering low-level cortisol release that, over years, contributes to inflammation and arterial damage. What makes noise pollution particularly resistant to policy intervention is its democratic distribution — it affects almost everyone, yet because it affects everyone, it rarely achieves the political salience of problems that concentrate harm in identifiable communities. The economist Rachel Lim has described this as 'the tragedy of the ambient': a cost so evenly spread that no single constituency has sufficient incentive to demand change.