By Matt Sloane
WebMD Health News
Nov. 10, 2014 -- On a bright, hot summer day in just about any major city in the world, there’s a slightly yellowish haze that hangs in the air. It’s the thing that makes sunsets appear fiery red, but it can be a dangerous health hazard for people living underneath. It's air pollution.
Several recent studies link air pollution to all kinds of medical conditions, from autism to obesity. While we know pollution is bad for our lungs, research suggests that might be just the tip of the iceberg.
“In the area of air pollution, the maxim is ‘the more you look, the more you find,’” says Norman H. Edelman, MD. He's the senior consultant for scientific affairs at the American Lung Association. “The more careful studies we do, the more [harmful] deleterious effects we find.”
There are two types of air pollution: particulates and smog. Both can cause serious health effects.
“Particulates are the very fine particles, not the ones you can see,” Edelman says, “and when particulate pollution goes up, there’s a significant increase in hospital visits for people with heart and lung disease.”
Particulate pollution largely comes from things like diesel exhaust, and wood-burning and coal-burning power plants, whereas smog or ozone is produced by smaller vehicle emissions.
Troubling Links
The most recent study on the bad effects of pollution found that pregnant moms who were exposed to a type of pollutant called polycyclic aromatic hydrocarbons, or PAHs, were five times more likely to have children who developed ADHD.
Researchers think these toxins might change the wiring in an unborn baby’s brain and increase their chances of having the behavior problems linked to ADHD.
A different study published just last month looked at the effects of two chemicals found in the air near some large factories and power plants: chromium and styrene. The researchers found that exposure seems to raise the risk of unborn babies getting autism in early childhood.
While those researchers also couldn’t say exactly why this effect seemed to be present, they hope future research might shed some light.
Another pollution study in Spain followed 620 children through the age of 4. It found that those who'd been exposed in-utero to higher levels of two chemicals found in air pollution -- nitrogen dioxide and benzene -- had a 22% to 30% higher risk of poorer lung function in early childhood.
And in yet another highly concerning study, American researchers looked at more than 100,000 women over 25 years, and found that those who lived closest to major roadways were more likely to die suddenly from heart problems. They even suggested that living near a major road could be statistically as big of a contributing factor in sudden cardiac death as smoking or obesity.
“Air pollution is a very big deal,” Edelman says. “Even though pollution levels are less than they were 20 years ago, it is still a very important contributor to poor health.”
source : Pollution Down, but Health Risks Persist
