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Plant a Safer Urban Garden

urban living

Community gardens offer city dwellers myriad benefits—bringing neighbors together to work on a common project, creating green spaces in an otherwise asphalt-and-concrete environment, even teaching kids where food really comes from.

But hold on a minute, say researchers from the Johns Hopkins Center for a Livable Future. Located so close to industrial sites and heavily trafficked roads, urban gardens can contain heavy metals, petroleum products, and asbestos. People who work or play in that soil, or eat the food grown in it, can be at risk of exposure to those kinds of contaminants.

A new study that appeared online in PLOS ONE found that urban gardeners generally understand that they should know how an urban garden site was used in the past, but they might lack the information and expertise to sufficiently determine the history. They also might not know how best to minimize their risk of exposure through things like soil testing.

Visit for CLF’s Soil Safety Resource Guide for Urban Food Growers.

Illustration of three potted plants with pipes beneath them
Naomi Elliott

Supply and Demand


Supply and Demand [medicine] Shortages of lifesaving medicine are the new norm. At any moment, some 300 drugs or more could be in low supply. In a consensus statement published in the journal Pediatrics, a group of prominent health care experts has proposed concrete steps for preventing and managing future shortages. “Some hospitals and health centers are simply better equipped than others to deal with the shortages and have more resources to bring to bear,” says Yoram Unguru, co-author of the document and a faculty member at the Johns Hopkins Berman Institute of Bioethics. This “Blueprint for Action” recommends such measures as the sharing of scarce drugs between health care institutions and developing a central online drug supply database.

The reasons for the shortages are complex but boil down to simple economies of scale. Once a drug can be produced generically, manufacturers might halt or limit production since it’s less lucrative. Some gray-market companies then gobble up the remaining drugs and mark up the cost as much as 650 percent. Most hospitals refuse to buy from these folks, but not all do, which creates an imbalance. “Our primary aim is to create a kind of ethical agreement and set of practices,” Unguru says, “so that all hospitals can play in the same sandbox.”

Toxic Time Bombs?


In a quest to create more durable plastics, manufacturers have started using something called carbon nanotubes, or CNTs, in products like bicycles, tennis racquets, sailboats, and packaging materials.

Some of these CNT-containing polymers are biodegradable, so they’re “greener” than petroleum-based plastics. Good, right? Maybe not, says Ed Bouwer, a professor of environmental engineering at Johns Hopkins. CNTs are toxic, and they could be released during wear of a product’s surface or during biodegradation. Their ultimate fate and impact will be dependent upon interactions with microorganisms present in landfills, soils, or surface waters.

“CNTs are like fibers. They have thin diameters and long lengths,” says Bouwer. “Their toxicity is analogous to asbestos fibers. They are sharp needles and can cause physical irritation to organisms. One health concern is inhalation and exposure to our lung tissue.” Bouwer and other researchers want to further study the health risks and determine acceptable levels of CNTs in these products, and how best to dispose of them.

Rewarding Altruism


Rewarding Altruism [society] Conventional thinking on compensating blood donors comes down to this: Giving should be its own reward. For four decades, the World Health Organization has frowned upon offering economic incen- tives for blood donation.

A recent study published in Science, however, argues that something more than a pat on the back can indeed motivate donors in certain instances and locations. Mario Macis, an assistant professor at the Johns Hopkins Carey Business School, says his team of researchers examined existing studies and conducted field research in Europe, Argentina, and the United States. They found that out of the 19 incentives tested in the field, 18 of these increased donations. T-shirts and supermarket coupons led to 16 percent more donations at American Red Cross drives, and a one-day paid leave was associated with 40 percent more annual donations in Italy. In Switzerland, the offer of a $5 lottery ticket increased donations by 5 percent, and a $10 gift card in the United States increased donations by 50 percent. Only one reward, a free cholesterol test, had no appreciable impact.

Illustration of a man holding a balloon and a woman reaching for it
Anna Parini

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