This brain looks clean, yours probably isn't.

Stockbyte/Getty Images

Air pollution has an obvious and powerful effect on our health. Asthma, heart disease, and even appendicitis have been linked to poor air quality. What has not been obvious is the effect low air quality has on the health of our brains.

A number of recent reports, based on research conducted around the world, have suggested that some of the most common pollutants, including black carbon, particulate matter and ozone, can inhibit vocabulary development, reduce reaction time, and even influence overall intelligence.

Children in New York City who were exposed to polycyclic aromatic hydrocarbons (PAH) while in the womb, one study found, scored four points lower on IQ assessments than children of the same age that had not been exposed to the same common urban air pollutants. Researchers pointed out that the performance drop is similar to that of children with mild lead exposure.

Frederica Perera, an epidemiologist and the director of the Columbia Center for Children's Environ

These weren't even superimpressively high levels of pollution...the levels we measured in our study are comparable to those in other urban areas.

It's not only fetuses in the delicate stages of development that are vulnerable to air pollution. A study conducted by the schools of public health at Harvard University and the University of North Carolina at Chapel Hill looked at individuals between the ages of 20 and 50 and found "ozone-related reductions in attention, short-term memory and reaction times equivalent to up to 3.5 to five years of age-related decline."