Researchers have trouble explaining why African American children are more likely than other children to suffer from asthma. A new study from Princeton University strongly suggests that much of the answer lies in the persistent segregation of people, which leaves many minority children growing up in unhealthy, polluted areas.
In the United States, these children are twice as likely to develop asthma. Past research has attributed such differences to low birth weight, as black babies are more likely than others to be born with a low birth weight, less than two thousand five hundred grams or 5.5 pounds, and low birth weight is a risk factor for asthma.
However, even when comparing low birth weight babies, scientists noted that black babies were more likely to develop asthma. The racial disparity in asthma rates is so great that some researchers have even concluded that being African American is already a risk factor for asthma.
When comparing low birth weight children of all races and ethnic groups who lived in black areas of New Jersey, where half or more of the inhabitants are African American, the racial imbalance in the association between low birth weight and asthma disappeared completely. In other words, all low birth weight children in these areas, regardless of their race, had an increased risk of developing asthma compared to normal weight babies.
Low birth weight can predispose children to asthma, but it does not cause illness by itself. A physical trigger is required. Thus, the researchers hypothesized that something in the neighborhood where low birth weight children live, regardless of their race, is causing them to develop the disease. This is important because, unlike race, external danger can be found and eliminated.
The study was unable to say conclusively what exactly causes asthma in low birth weight children in these areas. But it has been suggested that air pollution is to blame.
The researchers found that New Jersey neighborhoods with a majority of black residents are, on average, twice as close as other neighborhoods to major industrial sources of air pollution, and are often located near busy highways that produce high concentrations of harmful particulate matter. Housing in these areas is, on average, seven years older than elsewhere, and older buildings often contain mold spores and rodent and insect feces. Finally, people in these areas often smoke indoors.
It’s not just indoor and outdoor air pollution that can trigger asthma in susceptible children. To conduct the study, the researchers combined two datasets – records of all babies born to mothers who lived in New Jersey from 2006 to 2010, and records of all visits to New Jersey hospitals from 2006 to 2012.
Since the birth records included the addresses of the mothers, it became possible to trace which children were born in predominantly black neighborhoods. Emergency room records showed how many times each low birth weight child was admitted to the emergency room for asthma during the study period.
The United States is divided into neighborhoods, some of which are populated by low-educated African Americans suffering from poverty, unemployment, high levels of pollution and disease. Black Americans of all ages also tend to be in worse health conditions than their white counterparts. Research suggests that the characteristics of highly divided areas may be a major factor behind such differences in racial health.