By Mike Pomranz
Updated February 12, 2016
Credit: © Compassionate Eye Foundation/Steven Errico/Getty Images

Urban farming is becoming as popular of a big city activity as moving into a loft or paying some struggling actor to walk your dog. A new building in New York City is even looking to hire a full-time farmer-in-residence. But as one who has ever woken up to a morning forecast of smog might wonder, is it safe to grow produce in a concrete jungle? Modern Farmer decided to dig into this question and came up with the definitive answer of, yeah, pretty much.

According to their assessment, the two biggest baddies you may find contaminating the soil on your apartment building’s roof are heavy metals, especially lead, and polycyclic aromatic hydrocarbons or PAHs that come from a laundry list of terrible things like fuel emissions, paint and pesticides.

When it comes to the former, a recent University of Washington-led study determined that, even though urban soil can have higher levels of lead, the “benefits associated with urban agriculture far outweigh any risks.” Specifically, though the soil itself may be harmful, that doesn’t translate to the food grown in the soil being problematic. “We've shown that lead is harmful by eating the dirt, not from eating the lettuce grown in the dirt,” said lead author Sally Brown. The moral: Simply remember to wash your produce and wash your hands to get rid of excess dirt.

As far as PAHs are concerned, things are a bit more complicated, but primarily because less is understood about the impact of PAHs. However, it appears that, much like with lead, elevated levels of these chemicals in the soil doesn’t always translate to higher levels in food. Again, this means that simply washing your hands after gardening to avoid ingesting soil should be enough to keep you healthy – at least according to Johns Hopkins’ Soil Safety Resource Guide for Urban Food Growers published in 2014.

So, yes, as you look out the window of wherever you live, from New Haven, Connecticut, to Fresno, California, you might find yourself thinking, wow, this place is filthy. But maybe you should stop being so judgmental. Instead, just go eat a relatively safe tomato from the backyard and relax.