How common is autism in YOUR county? Shock data shows that one in twelve children has a disorder
A map has revealed America’s autism hotspots for the first time.
The number of cases of this condition has nearly tripled in children and young adults over the past decade, due in part to doctors’ ability to better diagnose the condition.
But that doesn’t explain the whole story: a review earlier this week highlighted air pollution as a major possible cause.
Now a study has revealed how US rates of childhood autism are disproportionately high in the Northeast and Southeast.
Worchester County Massachusetts and Chesterfield County in South Carolina, there was a whopping 8.1 percent of children with autism, or one in twelve. There were also clusters of hotspots around major cities like Los Angeles and Chicago.
Researchers say these differences are mainly due to hotspot areas having better access to hospitals or research centers, making it easier to diagnose.
But there may also be ecological and demographic factors. Many of the hotspot countries also had children from higher minority and low-income families, who have become more likely to be diagnosed with the disorder in recent years.
The researchers collected data from approximately 70,000 children and applied their findings to every county in the US. They then estimate higher levels of autism as hot spots, indicated in red, and lower levels of autism as cold spots, indicated in blue
Autism spectrum disorder is a developmental disorder that affects the way people interact, communicate, learn and behave with others. National reports say about one in 36 children has autism.
By understanding which regions of the country have the highest number of people with autism, researchers can better understand what outside influences contribute to the diagnoses.
In 2023, researchers from the University of South Carolina looked at this topic in their article published in the Journal of Autism and Developmental Disabilities.
They estimated autism rates in every county in the US by looking at data from 700,000 children.
The researchers gathered their information from the National Survey of Children’s Health, which asks parents to report on the health of their children between the ages of five and 17.
The survey randomly selected homes in each state and called them, asking, among other things, if their child had been diagnosed with autism.
They also recorded information about their race, gender, age and other health conditions, such as ADHD.
After obtaining this data set, the researchers used estimates from small areas to apply the observed patterns to the entire country.
They found that 3.29 percent of American children may have autism, slightly higher than a 2023 model from the CDC that put the rate at 2.8 percent.
The American Lung Association ranked the top cities suffering from the worst air quality in the US – affecting approximately 131 million Americans
They found that girls had lower rates of autism than boys, with 1.38 percent of girls diagnosed and 4.58 percent of boys diagnosed.
Meanwhile, 3.82 percent of black children were diagnosed, compared to 3.36 percent of Hispanic children and 2.87 percent of white children.
They found hotspots in the Southeast, the East Coast and the Northeast. Rates were particularly high in New Jersey, between 2.6 and 8.1 percent of the total child population.
Although the Southwest as a whole was considered low in autism, the researchers said there were small clusters of high diagnoses around Los Angeles and Las Vegas.
Rates of autism were especially low in the Texas Panhandle and in Oklahoma, where access to health care is notoriously difficult.
The researchers found that the rates in areas around California matched trends in autism diagnosis based on family income.
Overall, the overall rate of autism among affluent white children has decreased, while the rate of autism among poorer or middle-class white children has increased.
According to the researchers, this could be due to increased health care options for less affluent families, or greater awareness.
Poorer families are also more at risk of pregnancy complications and exposed to air pollution – two factors that can increase the risk.
According to a 2024 report from the American Lung Association, some of the most polluted cities are Los Angeles and Long Beach in California, Phoenix and Mesa in Arizona, and Denver and Aurora in Colorado.
Some of the cities highlighted as hotspots by researchers at the University of South Carolina also have high autism rates, such as Los Angeles, but not all.
Dr. Haitham Amal, head of the Laboratory of Neuromics, Cell Signaling and Translational Medicine at the Hebrew University of Jerusalem, recently published an article attempting to explain this increase.
It is thought that between 40 and 80 percent of autism cases are linked to inherited genetic mutations, but Dr. Amal’s new research has suggested a complex interplay of both genetics and environment as contributors to autism diagnoses.
The paper shows that people with genes linked to autism are more likely to develop it if they are exposed to pollution in the womb or in early childhood.
Scientists have not concluded that air pollution can lead to autism. However, the topic is being increasingly studied as the number of cases of autism increases worldwide.
Dr. Amal’s new research, which focused on four different types of air pollutants – including natural gases and substances produced during fuel production and combustion – can enter the bloodstream when inhaled.
From there, they can cause changes in the developing brain in a number of ways – leading to inflammation that affects the way the brain develops, or blunting the amount of chemicals the brain produces, according to Dr. Amal and his team.
Similarly, older research from Harvard University’s school of public health has linked exposure to an air pollutant called particulate matter and autism.
In these types of studies, it is difficult for researchers to rule out the influence of other factors that could distort the data, such as diet, smoking or exercise habits.
This is a problem behind many similar studies linking autism to air pollution, Amy Kalbrenner, an environmental epidemiologist at the University of Wisconsin, told me. Scientific American.
Dr. Kalbrenner said: ‘It’s the same weakness as other studies (on environmental pollutants and autism). They use an EPA model, which estimates what comes out of factories and traffic and spits out a pollution estimate.”
However, scientists also warn that the rise in autism diagnoses can be partly attributed to increased awareness about the disease.