Because many rural schools are usually located on cheap land, the students – who are often low-income and minority children -- are exposed to poor air quality. Most of these schools are near major freeways of hazardous sites.
The kids are constantly exposed to a variety of chemical pollutants such as lead, mercury, toluene, manganese, and polychlorinated biphenyls, according to a new study. The sources of these pollutants are industrial activities, combustion engines, refinery, waste incinerators, and mining.
Damage to neural tissues
Sara Grineski, a professor of sociology and environmental studies at the University of Utah and the lead author of the study, said that when these toxins are inhaled, they gain entry into the body. When the body mounts an immune response that causes swelling and neuroinflammation in the brain, it leads to damage to neural tissues, WESA reported.
In turn, damage to neural tissues has been linked to autism, ADHD, and later in life Alzheimer's disease and Parkinson's disease. Grineski said the neurological impact is so insidious and subtle that it is hard to know if a child has been affected or is being affected. Had these children lived in a different community, there is a possibility that their academic performance could have been better.
Just to show the profound effect of the damage on young, developing brains, Grineski cited another study conducted by Dr. Lilian Calderon-Garciduenas at the University of Montana. She performed autopsies on Mexican children who died in traffic accidents. Grineski said that the brains of kids from rural areas looked as were expected, but the brains of children from Mexico City -- a highly polluted area – showed signs of early-stage Alzheimer's disease.
Long-lasting harmful effects
When air particulate matter and its components such as metal are inhaled or swallowed, it passes through damaged barriers, including respiratory, gastrointestinal, and the blood-brain barriers which could result in long-lasting harmful effects, News.UMT reported.
The research by Calderon-Garciduenas compared 58 serum and cerebrospinal fluid samples from a control group who lived in a low-pollution city. They matched it by age, gender, socioeconomic status, education, and education levels achieved by their parents to 81 children who live in Mexico City.
The researchers found that the kids who live in Mexico City had significantly higher serum and cerebrospinal fluid levels of autoantibodies away from the brain. It is one of the features of brains of people who suffer from neuroinflammatory diseases such as multiple sclerosis.
The study established that the children have immune dysregulation. If there is a breakdown in the blood-brain barrier, it will not only allow particulate matter to enter the body but it would also open the door to harmful neurotoxins, bacteria, and viruses. A longitudinal follow-up study to determine if there is a relation between the cognition deficits and brain MRI alterations previously reported in Mexico City children was proposed by Calderon-Garciduenas.
Her study's focus was the children who lived in Mexico City. There are other students who are also exposed to alarming levels of air pollution such as those in Los Angeles, Philadelphia, Wilmington, New York City, Salt Lake City, and Chicago. Overseas, students in cities like Tokyo, Mumbai, New Delhi, Beijing, or Shanghai are at similar risk. There are 200 million people in the US who live in areas where pollutants such as ozone and final particulate matter exceed the benchmarks.
Worst polluted areas
In Grineski's study, published in the Environmental Research journal, out of almost 90,000 public schools studied, only 728 schools got the safest score possible. Based on air quality measurements of over a dozen neurotoxins, the areas that had the worst air pollution were in New York, Chicago, Pittsburgh, Camden, and Jersey City.
These areas have schools with a high percentage of African American, Latino, and Asian children. Grineski said that it is a pretty strong pattern that is statistically significant. She added that it is quite notable that the students from these racial, ethnic, minority backgrounds and poor students face higher levels of air toxins at their schools. Grineski said there is clearly an injustice present which reflects the broader issues related to racial and class discrimination in the country.
The schools are in bad locations because only 10 states have a policy that bans locating it in areas that are known to be environmentally hazardous. There is no such policy for 40 other states and Washington DC. To worsen matters, higher levels of pollution are found in schools that serve prekindergarten students than elementary students.
Grineski described the current situation as surprising and depressing because of the vulnerability of children to air pollution than adults due to their less developed lungs. At the same time, kids often spend more time outside and consequently consume larger quantities of oxygen per body weight. She said kids' exposure is higher while they are changing and their cells are growing much faster.
[researchpaper 리서치페이퍼= Vittorio Hernandez 기자]