Air pollution causes a “huge” reduction in intelligence, according to new research, indicating that the damage to society of toxic air is far deeper than the well-known impacts on physical health.
The research was conducted in China, but is relevant across the world, with 95 percent of the global population breathing unsafe air. It found that high pollution levels led to significant drops in test scores in language and arithmetic, with the average impact equivalent to having lost a year of the person’s education.
“Polluted air can cause everyone to reduce their level of education by one year, which is huge,” said Xi Chen (陳希) at Yale School of Public Health in the Connecticut, a member of the research team. “But we know the effect is worse for the elderly, especially those over 64, and for men, and for those with low education. If we calculate [the loss] for those, it may be a few years of education.”
Illustration: Mountain People
Previous research has found that air pollution harms cognitive performance in students, but this is the first to examine people of all ages and the difference between men and women.
The damage in intelligence was worst for those over 64 years old, with serious consequences, Chen said.
“We usually make the most critical financial decisions in old age.” said Rebecca Daniels, of the UK public health charity Medact. “This report’s findings are extremely worrying.”
Air pollution causes 7 million premature deaths a year, but the harm to people’s mental abilities is less well known.
A recent study found toxic air was linked to “extremely high mortality” in people with mental disorders and earlier work linked it to increased mental illness in children, while another analysis found those living near busy roads had an increased risk of dementia.
The new work, published in the journal Proceedings of the National Academy of Sciences, analyzed language and arithmetic tests conducted as part of the China Family Panel Studies on 20,000 people across the nation between 2010 and 2014.
The scientists compared the test results with records of nitrogen dioxide and sulphur dioxide pollution.
They found the longer people were exposed to dirty air, the bigger the damage to intelligence, with language ability more harmed than mathematical ability and men more harmed than women. The researchers said this may result from differences in how male and female brains work.
Derrick Ho (何鴻澤), a research fellow and health geographer at the Hong Kong Polytechnic University, said the impact of air pollution on cognition was important and his group had similar preliminary findings in their work.
“It is because high air pollution can potentially be associated with oxidative stress, neuroinflammation, and neurodegeneration of humans,” he said.
Chen said air pollution was most likely to be the cause of the loss of intelligence, rather than simply being a correlation.
The study followed the same individuals as air pollution varied from one year to the next, meaning that many other possible causal factors such as genetic differences are automatically accounted for.
The scientists also accounted for the gradual decline in cognition seen as people age and ruled out people being more impatient or uncooperative during tests when pollution was high.
Air pollution was seen to have a short-term impact on intelligence as well and Chen said this could have important consequences, for example for students who have to take crucial entrance exams on polluted days.
“But there is no shortcut to solve this issue,” he said. “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 China, air pollution is declining but remains three times above WHO limits.
According to the WHO, 20 of the world’s most polluted cities are in developing countries. China, home to several of those cities, has been engaged in a “war against pollution “for the past five years.
The results would apply around the world, Chen added.
The damage to intelligence was likely to be incremental, he said, with a 1 milligram rise in pollution over three years equivalent to losing more than a month of education.
Small pollution particles are known to be especially damaging.
“That is the same wherever you live. As human beings we have more in common than is different,” he said.
Aarash Saleh, a registrar in respiratory medicine in the UK and part of the Doctors Against Diesel campaign, said: “This study adds to the concerning bank of evidence showing that exposure to air pollution can worsen our cognitive function. 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.”
“The UK’s air is illegally polluted and is harming people’s health every day. Current policies are not up to the scale of the challenge: government must commit to bringing air pollution below legal limits as soon as possible,” Daniels said.
Because much of what former US president Donald Trump says is unhinged and histrionic, it is tempting to dismiss all of it as bunk. Yet the potential future president has a populist knack for sounding alarums that resonate with the zeitgeist — for example, with growing anxiety about World War III and nuclear Armageddon. “We’re a failing nation,” Trump ranted during his US presidential debate against US Vice President Kamala Harris in one particularly meandering answer (the one that also recycled urban myths about immigrants eating cats). “And what, what’s going on here, you’re going to end up in World War
Earlier this month in Newsweek, President William Lai (賴清德) challenged the People’s Republic of China (PRC) to retake the territories lost to Russia in the 19th century rather than invade Taiwan. He stated: “If it is for the sake of territorial integrity, why doesn’t [the PRC] take back the lands occupied by Russia that were signed over in the treaty of Aigun?” This was a brilliant political move to finally state openly what many Chinese in both China and Taiwan have long been thinking about the lost territories in the Russian far east: The Russian far east should be “theirs.” Granted, Lai issued
On Tuesday, President William Lai (賴清德) met with a delegation from the Hoover Institution, a think tank based at Stanford University in California, to discuss strengthening US-Taiwan relations and enhancing peace and stability in the region. The delegation was led by James Ellis Jr, co-chair of the institution’s Taiwan in the Indo-Pacific Region project and former commander of the US Strategic Command. It also included former Australian minister for foreign affairs Marise Payne, influential US academics and other former policymakers. Think tank diplomacy is an important component of Taiwan’s efforts to maintain high-level dialogue with other nations with which it does
On Sept. 2, Elbridge Colby, former deputy assistant secretary of defense for strategy and force development, wrote an article for the Wall Street Journal called “The US and Taiwan Must Change Course” that defends his position that the US and Taiwan are not doing enough to deter the People’s Republic of China (PRC) from taking Taiwan. Colby is correct, of course: the US and Taiwan need to do a lot more or the PRC will invade Taiwan like Russia did against Ukraine. The US and Taiwan have failed to prepare properly to deter war. The blame must fall on politicians and policymakers