View Full Version : Children who live near a busy road are more likely to develop ADHD

05-21-13, 06:41 AM

Unborn babies and infants exposed to high levels of traffic pollution are more likely to become hyperactive
Traffic particulates may cause narrowing of blood vessels and toxicity in the brain’s frontal cortex
Unborn babies and infants exposed to high levels of traffic pollution are more likely to become hyperactive, researchers have warned.

Scientists believe that early life exposures to a variety of toxic substances are important in the development of problems later in life.

The study suggest by the age of seven, children exposed to the substances are more likely to test positive for attention deficit hyperactivity disorder (ADHD) and related symptoms, including lack of attentiveness, aggression, and behavioural problems.

Traffic particulates may cause narrowed blood vessels in the body and toxicity in the brain’s frontal cortex, it was suggested.

Dr Nicholas Newman, from the Cincinnati Children’s Hospital Medical Centre in the U.S., said: ‘There is increasing concern about the potential effects of traffic-related air pollution on the developing brain.

‘This impact is not fully understood due to limited epidemiological studies.

‘To our knowledge, this is the largest prospective cohort with the longest follow-up investigating early life exposure to traffic-related air pollution and neurobehavioral outcomes at school age.’

The team collected data on traffic-related air pollution (TRAP) from the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS), a long-term epidemiological study examining the effects of traffic particulates on childhood respiratory health and allergy development.

Children born in the city between 2001 and 2003 were chosen based on family history and whether they lived near to or far from a major highway or bus route.

Children were followed from infancy to seven when parents completed a questionnaire about their behaviour.
This assessed attention deficit hyperactivity disorder (ADHD) and related symptoms including attention problems, aggression, conduct problems and atypical behaviour.

Of the 762 children initially enrolled in the study, 576 were included in the final analysis at seven years of age.

Results showed that children who were exposed to the highest third amount of TRAP during the first year of life were more likely to have hyperactivity scores in the ‘at risk’ range when they were seven years old.

Traffic particulates may cause narrowed blood vessels in the body and toxicity in the brain’s frontal cortex – this could result in ADHD in children
The ‘at risk’ range for hyperactivity in children means that they need to be monitored carefully because they are at risk for developing clinically important symptoms.

Dr Newman added: ‘Several biological mechanisms could explain the association between hyperactive behaviours and traffic-related air pollution, including narrowed blood vessels in the body and toxicity in the brain’s frontal cortex.’

However, higher air pollution exposure was associated with a significant increase in hyperactivity only among those children whose mothers had greater than a high school education.

Mothers with higher education may expect higher achievement, he says, affecting the parental report of behavioural concerns.

He said: ‘The observed association between traffic-related air pollution and hyperactivity may have far-reaching implications for public health.

Previous studies have shown that approximately 11 per cent of the U.S. population lives within 100 meters of a four-lane highway and that 40 per cent of children attend school within 400 meters of a major highway.

He said ‘Traffic-related air pollution is one of many factors associated with changes in neurodevelopment, but it is one that is potentially preventable.’

05-22-13, 11:49 PM
That's a pretty big leap from correlation to causation. Especially considering the fact that it's based on reported behaviours rather than neurological testing.

It's also possible that children living closer to major traffic areas have parents with lower SES (because homes in major traffic areas are less expensive). Adults with untreated ADHD often have lower SES (adults with diagnosed and treated ADHD as well) and ADHD is highly heritable. Just one possible alternate explanation.

09-24-13, 11:21 PM
I have read that higher levels of lead are found in the soil of yards where the homes are close to highways. It's a legacy of leaded gasolines, but it can affect kids who play in the dirt.

As lead poisoning affects mental processes, I wonder if this has anything to do with the correlation?

09-24-13, 11:54 PM
I came across this today regarding environmental chemicals and reproductive health that I thought may be suitable to share here. It is not adhd specific, but is related to exposure of chemicals:

Environmental Chemicals Harm Reproductive Health

Ob-Gyns Advocate for Policy Changes to Protect Health
September 23, 2013

Washington, DC -- Toxic chemicals in the environment harm our ability to reproduce, negatively affect pregnancies, and are associated with numerous other long-term health problems, according to The American College of Obstetricians and Gynecologists (The College) and the American Society for Reproductive Medicine (ASRM). In a joint Committee Opinion, The College and ASRM urge ob-gyns to advocate for government policy changes to identify and reduce exposure to toxic environmental agents.

The scientific evidence over the last 15 years shows that exposure to toxic environmental agents before conception and during pregnancy can have significant and long-lasting effects on reproductive health. “For example, pesticide exposure in men is associated with poor semen quality, sterility, and prostate cancer,” said Linda C. Giudice, MD, PhD, president of ASRM. “We also know that exposure to pesticides may interfere with puberty, menstruation and ovulation, fertility, and menopause in women.”

“As reproductive health care physicians, we are in a unique position to help prevent prenatal exposure to toxic environmental agents by educating our patients about how to avoid them at home, in their community, and at work,” Dr. Giudice said.
What can physicians do?

Learn about toxic environmental agents common in their community
Educate patients on how to avoid toxic environmental agents
Take environmental exposure histories during preconception and first prenatal visits
Report identified environmental hazards to appropriate agencies
Encourage pregnant and breastfeeding women and women in the preconception period to eat carefully washed fresh fruits and vegetables and avoid fish containing high levels of methyl-mercury (shark, swordfish, king mackerel, tilefish)
Advance policies and practices that support a healthy food system
Advocate for government policy changes to identify and reduce exposure to toxic environmental agents

09-25-13, 04:44 AM
In order for me to even personally consider the results of this study as valid, I would need to see the exact same study replicated on different subjects by different scientists. Good scientific data can be replicated to back up a theory or hypothisis.