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5 Challenges for America

Bringing public health strategies to five daunting challenges facing the U.S. is the goal of the new Bloomberg American Health Initiative. Here’s a closer look at these issues.

By Alexander Gelfand


Overdoses from heroin and the synthetic opioid fentanyl—a drug that is up to 100 times more powerful than morphine, and which can be lethal even at low doses—are devastating communities across the country, leaving public health and law enforcement agencies to search for answers.

In addition, those at greatest risk are among society’s most marginalized and vulnerable, such as sex workers and injection drug users—two groups that often overlap, says Susan Sherman, PhD ’00, a Health, Behavior and Society professor who works on HIV prevention and substance abuse intervention programs.

For example, Sherman’s ongoing National Institute on Drug Abuse–supported research in Baltimore has demonstrated high rates of illicit drug use among exotic dancers who also often sell sex in strip clubs; and fentanyl is frequently used to lace heroin, leading users to ingest it unknowingly. In advance of developing an intervention, Sherman is currently working on a study to examine the role of the police on the risk environment of street-based female sex workers, including cisgender (female born) and transgender, the former of whom are often drug users.

Addressing addiction, according to Sherman, requires understanding the complicated web of risks that such people face, and providing them with opportunities to improve their own lives, step by step. Sherman is investigating the viability of safe consumption spaces (SCS) in Baltimore. Such sites provide users with a place where they can consume drugs safely under clinical supervision—“there’s never been a fatal overdose in a safe consumption site,” Sherman says—while connecting them to a range of services, from medical care to addiction counseling. Although they do not yet exist in this country, there are now 100 SCS spaces in 66 cities around the world; research shows that establishing them leads to reductions in overdose deaths, hospital admissions and HIV and hepatitis C infection. Sherman is also looking into ways of testing the drugs that users might bring to such spaces for even trace amounts of fentanyl.

The goal, Sherman says, is to develop a multi-pronged toolbox for addressing addiction and overdose, and to provide integrated services that meet people where they are. That kind of approach not only affords drug users the dignity and respect that they deserve as human beings—the evidence shows that it will help save lives.


Once upon a time, the phrase “environmental hazards” referred mostly to threats like toxic chemicals and radiation exposure.

Those problems still exist. But today’s researchers must consider broader environmental issues across five large categories: climate change, land use, energy, water and food. Each of these has profound consequences for sustainability—and for individual and community health. And all are inextricably intertwined, for good and for ill.

Consider climate change and energy, for example.

Brian Schwartz, MD, MS, a professor in Environmental Health and Engineering, points out that the energy problem posed by the finite nature of conventional fossil fuels led to the exploitation of unconventional ones—such as oil extracted from tar sands and natural gas released through hydraulic fracturing.

The process for recovering, producing and distributing unconventional natural gas or tar sands oil is dirtier and more carbon-intensive than for their conventional counterparts, worsening climate change. That, in turn, could exacerbate the water shortages that some American cities are already facing, as rising temperatures contribute to more frequent droughts. And since water is used in both energy and food production, the negative consequences just keep piling up.

The U.S. food system relies on the inefficient use of vast amounts of water and fossil fuels to produce beef, pork and chicken, creating negative impacts on the environment and human health.

And cities that were designed for cars rather than for pedestrians and bicyclists not only burn more carbon, thereby contributing to climate change, but they also produce more air pollution and discourage physical exercise, exacerbating health problems.

“These are real things affecting our lives now, not just in 10 or 20 or 50 years,” says Keshia Pollack, PhD, an associate professor in Health Policy and Management.

Fortunately, addressing any one category of environmental challenges yields rewards in other areas, as well. “A single set of solutions can address all of them,” Schwartz says.

Pollack, for instance, notes that transit and land use policies that encourage people to drive less—and to walk and bike more—not only benefit the environment, but also improve physical and mental health.

By the same token, “green streets” and high-performance infrastructure that manage and filter storm runoff can make communities more resilient and sustainable. As climate change leads to more heavy precipitation events on one hand and more water shortages on the other, responses like these can help protect groundwater supplies from contamination while simultaneously replenishing them.


Obesity rates have skyrocketed over the past several decades, as have associated costs—from the physical and psychological toll on individuals to the billions of dollars in related health care expenses and lost productivity. (In addition to being at higher risk of diabetes and heart disease, obese people also miss more days at work.)

Many people continue to view obesity as a cosmetic problem or a simple failure of self-control, says Bruce Y. Lee, MD, MBA, executive director of the Global Obesity Prevention Center. Yet the evidence points in a different direction.

“Obesity is a systems problem,” says Lee, an associate professor in International Health. “It arises from many different systems gone awry, and it affects many different systems.”

It is also driven by a bewildering array of interrelated factors. A partial list includes everything from our basic metabolism to how we exercise, what we eat and the advertising we are exposed to—not to mention the cultural biases, government policies and economic incentives that influence what winds up on our plates.

And if all that weren’t complicated enough, says Joel Gittelsohn, PhD, a professor in International Health, obesity is more common among some groups than others. Low-income ethnic minorities such as Latinos, American Indians and African-Americans experience obesity at higher rates than the population at large and consequently must deal with higher rates of related chronic disease, as well.

Yet because the obesity epidemic contains such a long and convoluted list of ingredients, past efforts to address the problem through narrowly targeted policies and interventions have had little success.

There is hope, however.

The public health community is turning increasingly toward multilevel interventions that address several factors at once. Examples include programs that not only coax food wholesalers to supply more fruits and vegetables to urban convenience stores but also encourage retailers to promote those healthier options while simultaneously using community outreach and social media to persuade people to cook and eat them.

Researchers have also begun to use sophisticated computer models to simulate the many interacting parts of the obesity epidemic in much the same way that meteorologists simulate the complex systems that drive climate and weather. That, in turn, allows them to virtually test interventions and policies like urban farm tax credits in order to predict how they might ripple through the food system—and whether they could help fix it.


Research shows that adolescents are more likely than adults to act on impulse and less likely to consider the long-term consequences of their actions. As a result, they tend to engage in lots of risky behaviors, from smoking and drinking to unsafe sex. And, if left unaddressed, says Kristin Mmari, DrPH, associate professor in Population, Family and Reproductive Health, those behaviors can have serious repercussions later on.

The good news, says Mmari, who is affiliated with both the Center for Adolescent Health and the Center for Global Health, is that public health has already had some success in driving down rates of cigarette use and teen pregnancy.

The bad news is that risks to adolescent health have typically been treated in isolation—for example, through targeted, school-based programs that attack one problem at a time—rather than making larger gains by addressing multiple (and often related) risks at once.

Even the different kinds of data that have been used to evaluate the various risks to adolescent health have been kept in separate buckets. For instance, while researchers have sifted separate pools of data on the impact of schools, housing and media on youth, they have not combined these in a systemic way, Mmari says.

But research has shown that risks to adolescent health—including so-called social determinants of health like exposure to violence and lack of positive role models—tend to cluster among economically disadvantaged populations both at home and abroad.

What’s more, when it comes to adolescent health, the U.S. lags behind other developed countries. In part, Mmari says, that’s because poverty is such a powerful determinant of adolescent health, and inequality in this country is so great.

All of this suggests that the best way to support adolescent health is to take a holistic approach: one that addresses multiple factors that can either threaten or support it, from home and school environments to national policies. It also points toward tackling the problem in a comprehensive, integrated way, by addressing the many different threats to adolescent health that clump together among poor, vulnerable populations—and by engaging a broad range of community members, including adolescents themselves.

“I think adults need to listen to youth more,” says Mmari. Teens "know what they need.”


Homicide. Sexual assault. Bullying.

Violence comes in many forms. And research shows that it can’t be prevented by law enforcement alone. That makes finding novel solutions all the more urgent—even if the most effective responses aren’t necessarily the first that come to mind.

“Sometimes, they’re not so obvious.” says Daniel Webster, ScD ’91, MPH, a Health Policy and Management professor who directs the Center for Gun Policy and Research and co-directs the Center for the Prevention of Youth Violence.

Webster therefore judges potential interventions with a simple question: What does the data say?

For example, the Baltimore Police Department has tried for many years to reduce violent crime by enforcing drug laws. But Webster’s research has shown that this approach either had no impact, or was at times even counterproductive, since disrupting the market for illegal drugs can have the unintended consequence of breeding more competition among dealers, thereby leading to even more violence. The police department is now working with Webster on alternative approaches to deter illegal gun possession and remove the most violent offenders from communities.

Webster has also studied the impact of Safe Streets, a Baltimore City Health Department initiative that relies on community outreach workers to prevent shootings among high-risk youth. Based on an intervention that has been replicated in dozens of cities worldwide, Safe Streets utilizes outreach workers to identify and build trusting relationships with youth ages 15 to 24. In addition to serving as positive role models and connecting youth to job sand educational opportunities, outreach workers can rapidly intervene in disputes that have the potential to lead to gun violence. Webster’s research indicates that participants become more open to nonviolent forms of conflict resolution—and that, on average, Safe Streets neighborhoods experience a 27 percent reduction in nonfatal shootings.

In addition, Webster points to research demonstrating that a program aimed at providing summer jobs to high-risk teens in Chicago reduced violent crime arrests among participating youths by 43 percent over 16 months—despite the fact that the jobs themselves lasted only 8 weeks. The teens, who attended public high schools, were employed by nonprofits and government agencies and were provided with mentors. But while the investment required to run the program was relatively modest, the effect was not.

“These are the kinds of things we need to do in order to create change,” Webster says.

Sources: CDC, DEA, Youth Risk Behavioral Surveillance System, Child Trends Databank