Air pollution breathed in by thousands of people in Britain every day may be linked to a greater risk of developing autism, according to new research.
A review of the latest scientific literature found that babies with a higher genetic risk for the developmental disorder who were exposed to four common air pollutants were more likely to develop the condition.
It is thought that these microscopic pollutants, when inhaled during early childhood or in utero, can enter the bloodstream.
There they can bypass the brain’s protective layers, causing inflammation, changing the way nerves function and increasing the risk of disorders.
It’s because autism rates have exploded worldwide in recent years. Analysis shows that the number of diagnoses of the condition in Britain has risen by almost 800 percent in recent decades, while the number in the US has almost tripled.
Dr. Haitham Amal, head of the Laboratory of Neuromics, Cell Signaling and Translational Medicine at the Hebrew University of Jerusalem, who led the new study, said they were trying to understand what could be contributing to this increase.
His laboratory has mainly focused on nitric oxide (NO), a gas released when fossil fuels are burned in cars.
Dr. Amal said: ‘My laboratory has shown that NO plays an important role in ASD (autism spectrum disorder).’
This map shows the 10 areas with the highest levels of air pollution recorded in 2023. These areas had almost double or triple the levels of particulate matter, which are microscopic pieces of pollution that can penetrate deep into the human body, recommended by the World Health Organization. Organization
In the new study published in the magazine Brain medicinelooked at Dr. Amal four different components of air pollution: particulate matter, nitrogen oxides, sulfur dioxide and ozone.
Nitrogen oxides refer to both nitric oxide and nitrogen dioxide, two pollutants released when burning fossil fuels.
Particulate matter is a general term for the microscopic pieces of dust, liquid or smoke produced on construction sites, power plants and cars.
It is between seven and thirty times smaller than the diameter of a human hair.
Sulfur dioxide is a colorless gas or liquid that is produced by the combustion of fossil fuels or the melting of metal such as aluminum.
Ozone is a colorless, odorless gas produced by chemical plants, oil-based paint factories, and printing plants. It can also form when other pollutants mix with the atmosphere.
The authors did not provide figures, but older research from Harvard suggests that exposure to air pollution such as particulate matter can increase the risk of autism by as much as 64 percent.
A review of the latest scientific literature found that babies with a genetic predisposition to autism who were exposed to four common air pollutants were more likely to develop the condition
Doctors aren’t sure what causes autism, but about 15 percent of cases are linked to a specific gene mutation.
Experts also don’t know exactly why the risk of developing the condition is linked to air pollution, but they have theories.
First, when someone inhales any of these pollutants, it can cause inflammation in the nerves that damage them over time and lead to dysfunction.
People are most vulnerable to these conditions when they are developing in the womb and in early childhood because their brains are still forming, Dr. Amal said.
Studies have shown that these tiny pollutant particles can even directly enter the fetus’ brain, he said.
Long-term changes in the way the brain functions can cause some of the behavioral symptoms associated with autism, he added.
NO is just one of the substances released by the combustion of fossil fuels, mainly through energy generation and transport.
Air pollution in general is measured by recording the levels of particulate matter (PM2.5); the levels of microscopic particles in the air that can penetrate deep into our lungs and cause a range of health problems.
Dr. Amal (center) and his team of researchers in their laboratory in Jerusalem. The team focuses on nitric oxide and its role in the brain
Surbiton in south-west London recorded the worst average PM2.5 levels in Britain at 13 micrograms per cubic meter in 2023, according to data collected by website IQAir.
This is almost triple the World Health Organization guideline of 5 PM2.5 that people should be exposed to per year.
Other areas with high PM2.5 levels in Britain included Willesborough, Faversham and Lower Stoke in Kent, Worcester Park in London and Worsley in Greater Mancester.
In contrast, Church Hill in West Sussex had the lowest PM2.5 level in 2023, at just 3.8.
This was followed by West Hoathly, also in West Sussex at 4pm 2.5 hours for the year, as well as Motherwell and Currie in Scotland, which recorded 4.10pm 2.5 hours.
Data from 2023 shows that nine areas in Britain did not meet annual average nitrogen dioxide limits of 40 micrograms per cubic meter.
There was Greater London, the West Midlands, Greater Manchester, West Yorkshire, Liverpool, Nottingham, Bristol, Coventry/Bedworth and the South East.
When you have autism, a person’s brain works differently than normal.
It is not a disease and people have the disease from the moment they are born, although the disease may not be noticed until childhood and sometimes much later.
Autism exists on a spectrum. Some people will be able to live a fully functioning life without additional help. Others may need full-time help.
Classic signs of autism include communication problems, finding certain stimuli or overwhelming situations, and repetitive behavior.
According to a 2021 study by Newcastle University, around one in 57 children in Britain is autistic.
Yet figures have risen dramatically in recent years, prompting suggestions that the disorder is now over-diagnosed.
However, experts claim that autism has historically been vastly underdiagnosed, especially among women and girls.
This subsequently led to a backlog of patients who were diagnosed at a later age.
An additional factor that could have contributed to the increase is the retirement of Asperger’s syndrome, which was once considered a separate condition but is now considered another form of autism that is also driving up the numbers.