By listing the most serious environmental risks to public health, air pollution ranks high. Such a situation does not arise from a fiction story. Each year, air pollution is estimated to cause nearly four million premature deaths, while indoor air pollution kills an additional three million people.

Currently, the most dangerous pollutants identified so far are nitrogen dioxide and fine particulate matter PM2.5. Both come from vehicle activity on the roads, gases from certain industries and even cooking in homes and restaurants, where particles tend to concentrate and cause problems in the heart and lungs in the long term.

So far, most countries have laws that help regulate and keep air pollution under control. However, while the World Health Organization (WHO) claims that the legal limit for PM2.5 is 10 micrograms per cubic meter of air per year, some countries like England maintain the limit at 25 micrograms per cubic meter of air per year, Which certainly makes us wonder: what do we know about safety limits for air pollution?


When can we say there’s too much pollution?

In most cases, knowing when there is increased exposure to PM2.5 particles is only possible through a study, which evaluates the relationship between health conditions and the type of exposure to contaminants in a wide group of people.

As William Bloss, Professor of Atmospheric Sciences at the University of Birmingham, points out, "Such studies, which resemble those carried out by epidemiologists to study diseases such as COVID-19, capture the health effects of air pollution and are carefully designed to remove the influence of other pollutants, as well as demographic and socio-economic factors. Along with this, researchers study how air pollutants enter the body and affect organs such as the lungs, heart, and brain".

However, more recent research has shown that there is no level of exposure to PM2.5 at which there are no adverse health effects. In other words, pollution and its impact on health will always exist, so beyond seeking to eradicate this problem, measures must be taken to keep everything under control, protecting the most vulnerable people and preventing levels from growing out of control.


Upholding the rules

At a time when various governments around the world are setting their air quality targets, the WHO continues to encourage measures to unify the 10 microgram limit of PM2.5 by 2025 in all countries. Given this, there is a great opportunity to develop laws that make the air safer to breathe, rather than simply keeping pollution levels at a safe limit.

Usually, limits are only taken into account to continue polluting up to a certain level. When the limit is exceeded, some measures are taken and then the cycle is repeated.

According to Professor Bloss, "carefully designed air quality standards can balance both approaches, providing health benefits for the entire population and ensuring that no area is exposed to disproportionately high levels of pollution".