Could the Environment Cause Asthma?

In one of the schools we visited for our study, a boy had just died of asthma.

Asthma is the most common chronic disease among children in industrialized countries.  In some communities, childhood asthma is so common that parents expect it as just another part of growing up, like tantrums and falling baby teeth.  For instance, in many of our Latino communities, childhood asthma is referred to as “fatiga” or fatigue, and may not be recognized as a major illness.  This may also prompt a sense that there is nothing that can be done because so many children have it, it is a fact of life.  In our work, we have identified some schools in which one in every 5 children had symptoms of asthma.
So why, why, why do so many children have asthma?  And why, at least until recently, it seemed to be on the up, and up, and up?  No one really knows, but I will venture an educated guess.
During my years of medical research training, I was taught that air pollution did not cause asthma.    It was believed that air pollution triggered asthma symptoms in those who already had it. That was the dogma for many years and that is what medical professionals have been taught.

Now, evidence shows that air pollution may actually cause asthma by affecting lung development in infants.  This effect on lung development may put infants at higher risk of developing asthma later in life.  My colleagues at University of California at San Francisco showed in a study that African American and Latino infants living in communities with high air pollution coming from cars were more likely to develop asthma than those growing up in areas that had less air pollution.   
The UCSF investigators studied more than 4,000 African American and Latino children in the San Francisco Bay Area and Puerto Rico.   They zeroed-in on an air toxic that mostly comes from car exhaust, nitrogen dioxide, and found that babies exposed to the higher levels were more likely to have asthma years later.  
But one of the more interesting things that they discovered was that the effect was seen even at levels that were well below what the EPA considers “safe”.   As with many other pollutants, infants and children are the most vulnerable and they need to be considered when regulatory agencies set standards for what should be considered a “safe” level of a chemical in the environment.  
This study in California brings to mind our own studies that have consistently showed higher levels of asthma in Latino and African American communities in New York.  Years of research have shown that African American and Latino communities are highly exposed to air pollution and other environmental contaminants, a situation termed “environmental injustice”.  But air pollution is everywhere, and although minorities seem to bear the brunt of its effects, contaminated air affects everyone exposed.  
I don’t know about you, but I am tired and “fatigued” of visiting school after school where children pay such a heavy price for our need for speeding cars down the highway.  I’d like to see them fatigued from the sheer fun of playing ball at recess.