The Cognitive and Toxic Ecology of Impoverished Neighborhoods

05/11/2015 02:35 pm ET | Updated May 08, 2016

On April 15th, 2015, Freddie Gray, a 25 year old African American man, was arrested by the Baltimore Police, hand and leg cuffed, and thrown into the police van. In the process, Freddie suffered a spinal cord injury, from which he died. Six police officers were indicted in his death.

The death of another young black man at the hands of the police pushed the community over the edge. Small protests grew larger and larger, until, in the night of Freddie's funeral, on April 27th, they erupted into rioting and looting. After a year of similar deaths ranging from Fergusson, Missouri to Staten Island New York, Americans have been asking, why do the conditions of persistent poverty exist in such a wealthy nation?

Freddie was not destined to be a local hero- he never graduated from high school, and since then had been arrested more than a dozen times for drug possession. But the deck was stacked against Freddie from the moment that he was born.

Freddie's mother was a heroin addict. He was raised in North Baltimore, in an impoverished neighborhood, suffused with drugs, violence and crime. He grew up with neglect and disorder, which has been shown to negatively effect a child's cognitive development. When Freddie was a small child, he and his twin sister Fredericka were also exposed to flaking lead based paint, were tested, and found to have excessive levels in their blood. Both were classified as suffering from ADHD in school, and ultimately dropped out. Freddie turned to drugs, Fredericka was often violent. Ruth Ann Norton, the executive director of the Coalition to End Childhood Lead Poisoning, in a Washington Post article by Terrance McCoy said "A child who was poisoned with lead is seven times more likely to drop out of school and six times more likely to end up in the juvenile justice system." (1)

A blood level over 5 micrograms of lead per deciliter of blood is likely to severely disturb a child's cognitive development, leading to lack of executive function, emotional self regulation and an inability to pay attention. Without these skills, children often fail at school, drop out, and develop criminal records. When Freddie was 22 months old, blood tests revealed that he had 37 micrograms of lead per deciliter of blood.

"Jesus," Dan Levy, an assistant professor of pediatrics at Johns Hopkins University who has studied the effects of lead poisoning on youths, was quoted as saying in the Washington post article when told of Gray's levels. "The fact that Mr. Gray had these high levels of lead in all likelihood affected his ability to think and to self-regulate and profoundly affected his cognitive ability to process information. And the real tragedy of lead is that the damage it does is irreparable." (2)

Environmental toxins negatively impact neural development, measurably degrading the intelligence of children, especially if their mothers are exposed during pregnancy. Outdoor air pollution generated by burning fossil fuels pollutes air with polycyclic aromatic hydrocarbons (PAH), methylmercury (Me Hg), sulfur, nitrogen oxides, and other toxins. These pollutants also effect adults. A study recently published the medical journal Stroke found adults who lived near highways, and were exposed to high levels of PM 2.5 particulates had a 46% greater chance of getting a stroke. Each additional 2 micrograms of PM 2.5 per cubic meter of affected the brain as though it had aged a year. (3)

Dr. Fredericka Perrera of the Mailman School of Public Health notes that the direct toxic effects of exposure to these chemicals leads to increased infant mortality, lower birth weight, deficits in lung functioning, childhood asthma, developmental disorders, intellectual disabilities, attention deficit hyperactivity disorder, and an increased risk of childhood cancers. Prenatal or early life exposure to alcohol, nicotine, and cocaine also can have what the Center on the Developing Child calls devastating and lifelong effects on the developing architecture of the brain.

There is not a great deal of work on the combined cognitive effects of toxic stress and toxic chemicals, but they cannot be good. If a child's immune response is rendered less effective by cognitive stress, then they are likely to be more vulnerable to neurotoxins and other stresses. This toxic soup is pervasive, but to many, invisible. It is critical that we identify its components and its compounding effects.

In addition to lead, other environmental toxins such as mold, pests, pesticides, and excessive dust have been shown too adversely effect children and their families. All of these toxins may be present in any home, but they are typically concentrated in low-income homes and neighborhoods. In these poorly insulated homes, during cold winters, families often use gas-fired ovens, and stoves, for heat deeply, adding to the toxicity of the indoor air . An unpublished study indicated that the children most vulnerable to environmental toxins were more likely to have parents who suffered from the cognitive deficits of poverty - the combination of the persistent stresses of negotiating an under- resourced life, poor nutrition and environmental toxins depleted their parents' intellectual capacity to understand the issues that were effecting them, and to develop alternative strategies. And thus their children were subject to higher levels of exposure. Freddie and Fredercka's mother knew that her children were ingesting lead, but she could not afford to move elsewhere.

Contemporary urban life is complex, and only getting more so. Intellectual intelligence is increasingly required to figure out how to negotiate cities' dynamic systems. Emotional and social intelligence is increasingly required to thrive in complex organizations. Children who are raised in highly stressed, environmentally toxic environments will be much less likely to succeed. And in the competitive 21st century, can a city thrive when a significant portion of its residents can't participate in its culture and economy? Most likely not.

The riots in Baltimore revealed how deep the rifts are between prosperous and poor neighborhoods in most American cities.

Is the American Dream large enough so that every one of its children has the opportunity to live in a safe, affordable home?

(To join the movement for safe, affordable housing click on: )