Breathing air near highways and roads is now being shown to cause and/or worsen many health problems. Gasoline and diesel fuel contain highly toxic chemicals including benzene, xylene, toluene, and other poisonus compounds. When these are burned in the engine combustion process, they form new highly toxic chemicals including dioxin and a group of chemicals called polycyclic aromatic hydrocarbons (PAH for short). This page summarizes a number of research studies showing how car exhaust can accelerate the aging process, damage the immune system and increase rates of child asthma, autism, ADHD, depression, diabetes, Alzheimer's, anxiety and also lower child IQ. The true cost of operating gasoline powered cars is therefore, grossly underestimated as the actual cost should take into account the increased medical expenses for treating and taking care of individuals whose health has been affected by this type of localized pollution. The research below should give weight to the critical importance of rapidly accelerating the move away from gasoline powered vehicles and to other fuel sources such as natural gas and electric. We review the research on this topic below and provide links to the original scientific studies reporting this information.

Child Asthma Increases if Homes or Schools are Near High Traffic Areas

SOURCE:  Environmental Health Perspectives, 118(7):1021-6, July, 2010
View online journal HERE

120 new cases of childhood asthma were reported during a follow-up of kindergarten and 1st Grade children who were asthma and wheezing-free at study entry into Southern California Children's Health Study. Researchers assessed traffic related pollution exposure based on traffic volume and distance from home and school. Asthma rates in chil dren increased by 50% for higher exposure from roadways near homes and by 45% when higher exposure occurred near schools. The scientists concluded by stating:

Traffic-related pollution exposure at school and homes may both contribute to the development of asthma.
McConnell R, Islam T, Shankardass K, Jerrett M, Lurmann F, Gilliland F, et al.
University of Southern California, Los Angeles, California

Autism 3x Higher for Children Living Near High Traffic Roadways

SOURCE:  JAMA Psychiatry, 70(1): 71-77, January, 2013
View online journal HERE

Children living within 309 meters (1000 feet) of a "freeway" were shown to have a 3x greater risk of developing autism compared to children living beyond this distance. Scientists at the Department of Public Health Sciences at the University of California conducted the study along with several other agencies. A total of 279 children with autism were compared to 245 control children. Car exhaust contains many hazardous chemicals that move away from the highway toward surrounding homes and are found in highest concentration closer to the traffic areas.

Dept. of Preventive Medicine and Pediatrics
Keck School of Medicine
Children's Hospital, Los Angeles
University of Southen California

Attention Deficit Behaviors Higher for Children Exposed to Auto Exhaust

SOURCE:  Environmental Health News, November 5, 2014
View online journal HERE

New York City pregnant mothers exposed to higher levels of car exhaust had children with
5 times greater risk of attention problems at age 9. Researchers at Columbia University measured the amount of a car exhaust chemical known as benzo[a]pyrene in 233 African-American and Dominican women in New York City. Children with the highest amounts of the chemical had a 5 times greater risk of of showing behaviors associated with inattention when compared to children whose mothers had the lowest levels.

Frederica Perera
Columbia Mailman Schol of Public Health
Columbia University

Automobile Exhaust Chemicals Lower Intelligence

SOURCE:  Neurotoxicology Teratology, 49:74-80, May-June, 2015
View online journal HERE

276 minority urban children in New York City were followed through age 7 to determine if higher exposure to chemicals in typical car exhaust negatively affected intelligence. Mothers were measured for car exhaust exposure beginning just after conception and throughout pregnancy. Results showed children exposed to higher vehicle traffic were found to have significantly reduced IQ as measured on the Wechsler Intelligence Scale for Children. These results are of great concern as lower IQ is associated with decreased academic success and decreased future income. Car exhaust is a major source of the carcinogenic and neurotoxic chemicals polycyclic aromatic hydrocarbons (PAH).


Department of Enviornmental Health Sciences
Mailman School of Public Health
Columbia University, New York

Depression/Anxiety and Attention Problems Higher
in Children Exposed to Automobile Exhaust

SOURCE:  Environmental Health Perspectives, Vol. 120(6), June, 2012
View online journal HERE

Children of nonsmoking African-American and Dominican women in New York City were followed from pregnancy to 6-7 years. During pregnancy, mothers wore personal air monitoring devices to measure exposure to automobile exhaust chemicals known as polycyclic aromatic hydrocarbons (PAH), including the chemical benzo[a]pyrene (BaP). Results showed that when pregnant mothers were exposed to levels above 2.27 ng/m3, there was a positive association between child symptoms of Anxious/Depressed and Attention Problems.

Dept. of Environmental Health Sciences,
Mailman School of Public Health
Columbia University, New York
Southwest Research Institute, San Antonio, Texas

Diabetes 30% Higher if Living Near Highway

SOURCE: Environmental Health, Vol. 14: 53, June 2015
View online journal HERE

People living closer than 330 feet (100m) from a major highway had significantly more cases of diabetes than people living more than 660 feet (200m). Researchers from a number of universities in Germany followed 3,607 individuals without diabetes in 2000-2003 for an average of 5.1 years and then compared rates of diabetes for the two groups. Those living less than 330 feet (100m) had 30% more cases of diabetes than those living more than 660 feet (200m) away.


Leibniz Research Institute for Env Med
Medical School, einrich Heine Univ.

Alzheimer's Increases Living Closer to Highway

SOURCE: Lancet, Jan. 4, 2017
View online journal HERE

The risk of developing Alzheimer's Disease increases the closer someone lives to a major highway. The study was conducted in Ontario, Canada and found that people living from 100-200 meters from a high traffic highway had a 2% increase risk of Alzheimers Disease. People living 50 to 100 meters had a 4% increased risk and those living less than 50 meters had a 7% increased risk of getting Alzheimers. If the families had lived there for a longer time the risk increased to 12%. Researchers also investigated increased risk for Parkinson's Disease and Multiple Sclerosis but only Alzheimer's rates increased from traffic exposure.