Women who live in heavy traffic areas such as the Northern Manhattan and South Bronx areas of New York City, could give birth to children with an increased risk of asthma due to what are called toxic PAH’s (Polycyclic Aromatic Hydrocarbons).
The finding came from a study of the umbilical cord blood from New York City children, in which researchers found a change in a gene (called ACSL3) associated with prenatal exposure to polycyclic aromatic hydrocarbons.
Most commonly, PAHs are released into the air when fossil fuels, gasoline and garbage are burned, and as such perhaps the most common route of exposure to these chemicals is by breathing contaminated air. PAHs exist in cigarette smoke, wood smoke, vehicle exhaust, diesel exhaust and asphalt roads, as well as in the air of industrial coking, coal-tar and asphalt production facilities, along with trash-incinerating facilities.
Because of this, air in urban areas may have PAH levels 10 times higher than those in rural areas.
While exposure to PAHs has previously been linked to cancer, childhood asthma, cataracts, kidney and liver damage and other diseases, the new study found the chemicals result in epigenetic changes that may disrupt the normal functioning of genes by altering their expression.