Is Pollution Reducing Our Intelligence?

The damaging effects of air pollution on the body’s heart, lungs and other important organs is well-documented, but it now appears that the impact it has on our mental capacities could be just as serious. According to a new Chinese study on how exposure to poor air quality impacts cognitive performance, high levels of pollution could be equivalent to missing out on a whole year of education.

The study was undertaken by researchers from the Yale School of Public Health in the USA, but used raw data obtained from the China Family Panel Studies and was published in the scientific journal Proceedings of the National Academy of Sciences. Although it focuses solely on 20,000 Chinese subjects, the results of the study are relevant to 95% of the global population who are exposed to poor air quality on a regular basis.

A growing body of evidence

The study is not the first time that air pollution has been linked to poor cognitive performance, but it is the first time that such tests have been performed on a group other than just school pupils. Moreover, it’s also the first study to examine specifically how pollution can affect different cognitive functions and the differences between males and females in response to their exposure.

Using data gathered from over 20,000 participants of all ages from the years 2010 to 2014, the study measured the subjects’ ability to solve mathematical and linguistic problems. It found that there was a clear correlation between those who had been exposed to pollutants for a longer time and those who performed poorly in tests. Language abilities were more directly affected than mathematical ones and males seemed to show greater susceptibility to damage than females, as well.

In order to account for other causal factors such as genetic differences and the natural decline in cognitive ability through the passing of time, the study followed subjects from one year to the next throughout the test period. In this manner, they were able to conclusively point to air pollution as the cause of poor mental performance, equating it to being the same as losing one whole year of education.

Action needed now

The study’s authors have pointed to its findings as further proof that air pollution is a serious problem which demands immediate action in China and elsewhere. “There is no shortcut to solve this issue,” explained Xi Chen, one of the researchers involved in the study. “Governments really need to take concrete measures to reduce air pollution. That may benefit human capital, which is one of the most important driving forces of economic growth.”

In the UK, concerned parties have called on the British government to take heed of the study and implement measures to actively improve air quality and reduce transport-related pollution. Dirty fumes from vehicle exhausts are believed to be the biggest contributing factor in urban towns and cities - which is also where the majority of the populace lives.

“This study adds to the concerning bank of evidence showing that exposure to air pollution can worsen our cognitive function,” said Aarash Saleh, a proponent of the Doctors Against Diesel campaign. “Road traffic is the biggest contributor to air pollution in residential areas and the government needs to act urgently to remove heavily-polluting vehicles from our roads.”