A Tale of Two Cities
What is the effect of living in fear? Researchers are finding that stress-filled neighborhoods can be hazardous to your health—in many different ways.
Sometimes, Baltimore feels like two different cities.
In a leafy enclave northwest of the Johns Hopkins University Homewood Campus, 39-year-old acupuncturist Katherine Porter takes her 8-month-old daughter, Tess, for a morning stroll. Porter and her husband chose the tree-lined Keswick neighborhood for its safety and convenience. Katherine walks to work, to a nearby market for food shopping, to her daughter's pediatrician for check-ups, to nearby Linkwood Park for relaxation, and up the street to a restaurant for an evening meal. "It's the best spot in the city," Porter says.
Only a few miles south, 51-year-old Michelle Brown sits on a stoop watching nine children—some relatives, some not—play in a litter-filled lot. For four years, she has lived in one of six connected row houses with her daughter and three grandchildren. Two of the houses stand abandoned, magnets for rats and other intruders. There's no shade, no nearby park and no escape.
"You can feel the differences in these neighborhoods," says Thomas A. Glass, PhD, associate professor of Epidemiology. "But what is the effect of having to look over your shoulder? What is the effect of fear? What is the effect of constantly having to scan the environment? We know that this has to do something physiologically to people."
In an attempt to find some answers, Glass founded a citywide group called the Baltimore Neighborhood Research Consortium in 2002 to coordinate academic research.
He also started working with Brian S. Schwartz, MD, MS, professor of Environmental Health Sciences, who is principal investigator of the Baltimore Memory Study (BMS), a population-based study looking at the causes of cognitive decline in older urban residents.
As part of the broader BMS effort, Glass developed a detailed analysis of 65 Baltimore neighborhoods, ranking them according to how stressful they are for residents. This Neighborhood Psychosocial Hazard Index (NPH) combines 12 variables including crime, unemployment, 911 calls and number of abandoned buildings to tap into features that give rise to vigilance, alarm and fear.
Glass and colleagues found that stress does indeed vary greatly depending on where you live. Baltimore neighborhoods such as Keswick, Homeland, Canterbury, Mayfield and Guilford, for example, scored very low on the NPH Index, indicating residents are exposed to low environmental stress. Other areas such as the Druid Heights, Greenmount West, Oliver, Barclay and Upton neighborhoods scored sky-high, indicating residents are exposed to high levels of psychosocial stress.
In the first study using this NPH Index, Glass and colleagues analyzed the body mass index of 1,140 randomly selected men and women, ages 50 to 70 years old, from the 65 Baltimore city neighborhoods. The researchers found that residents living in the most hazardous neighborhoods were nearly twice as likely to be obese as those living in the least hazardous neighborhoods, even when results took into account individual risk factors like gender, poor diet and exercise.
"We think it's a very elegant theory because all mammals are designed genetically to put on additional weight in the presence of stress," says Glass, who collaborated with Syracuse University's Meghan D. Rasmussen, MPA, and Schwartz on the study, which they expect to appear in the American Journal of Preventive Medicine this fall.
In a second study being prepared for publication, Glass and Schwartz found that neighborhood stress can also exacerbate the cognitive problems associated with lifetime lead exposure in older adults.
For that study, the researchers compared the impact of lead stored in bones after lifelong exposure to leaded gasoline, lead paint and other sources on cognition and whether that impact was greater in persons living in more stressful neighborhoods. The researchers hypothesized that neighborhood psychosocial hazards could lead to rises in cortisol that might make the effect of lead even worse. That is what the data showed. "From studies of lab animals we know that lead and cortisol work together to increase the damaging impact of each other, but no one had seen this in older adults," Glass says.
"It's no different than my last neighborhood," says Michelle Brown. "It's OK. But I really don't have a choice."
The findings: For three of seven cognitive tests, living in a hazardous neighborhood made the influence of lifelong lead exposure on cognitive dysfunction worse. Residents of hazardous neighborhoods scored lower on these cognitive tests than residents of safe neighborhoods, even when stored lead levels in the body were the same.
"With this and other studies," says Glass, "we're putting together the pieces of a very interesting puzzle."
In addition to their studies on obesity and lead, Glass and other Bloomberg researchers are using NPH mapping to look at the impact neighborhoods might have on heart attacks, strokes and social interactions.
On the streets of Baltimore, the NPH Index translates into a gut feeling about where you live. It's not about race, or money, or pretty houses, Glass says. It's about residents' comfort level and their ability to achieve a healthy lifestyle in their environments.
The 102-home Keswick area, where Katherine Porter and her family live, has the lowest psychosocial hazard ranking in the city. It's easy to see why: Tudor-style brick homes, with well-kept gardens, sit on tree-lined city streets. An active neighborhood association keeps residents informed about issues such as the maintenance of city trees. At the intersection of Wickford and Wingate Roads, a cherry tree surrounded by three cement benches provides a welcome gathering place for neighbors.
Contrast that with Brown's situation. She lives in an area that ranks among the highest in psychosocial stress. As she sits watching the kids play, she notes that there isn't much for the children to do within walking distance—no swimming pools, no parks and no air-conditioned gyms. She worries about crime, the abandoned houses next door and other realities of her environment. "I've called the city to see if they can cement this alley, but they've never gotten out here," she says.
Brown doesn't own a car, so she waits for her son to come by weekly to take her to a grocery store. Other than that, she buys her staples at the drugstore around the corner. "It's no different than my last neighborhood," Brown says. "It's OK. But really I don't have a choice."
Reversing this disparity in residential neighborhoods may hold the key to improving urban health, Glass says. "If people can't get access to decent food, if they are afraid to leave their houses, if they are surrounded by scary stuff, then we're not going to meet our public health goals," he says. "Some problems are going to require solutions aimed at making people feel safer and less threatened in their homes."