Pregnant women being exposed to environmental pollutants known as polycyclic aromatic hydrocarbons (PAHs) can negatively impact their child's resulting intelligence quotient; commonly known as IQ,

The news comes from research carried out by the the Columbia Center for Children's Environmental Health (CCCEH) at the Mailman School of Public Health.

Polycyclic Aromatic Hydrocarbons are generated as the result of burning of fossil fuels such coal, diesel, oil and gas and other substances including tobacco. While most of us don't live next to coal fired power stations, urban dwellers do have many opportunities for exposure through cars and other forms of transport.

The study found that children exposed to high levels of PAHs in New York City had IQ scores that were over 4 points lower than those of less exposed children; a similar drop to what would be experienced through low level lead exposure and enough to affect a child's learning ability.

With so much focus on carbon emissions these days, it's easy to forget there's also other nasty chemicals in our air thanks to human activity that negatively impacts on us and the wider environment. Some of these chemicals are pervasive, traveling thousands of miles from their generation source to the most remotest corners of our planet.

Airborne PAH concentrations, like the lead threat of years ago, can be mitigated through emission control policies and greater utilization of renewable energy sources such as solar power. As with oil, this is just another reason we must kick the coal habit. Even "clean coal" technologies aren't able to prevent some of the toxic chemicals from burning coal from entering our atmosphere.

Learn more about air pollution and our environment.