Is it safe to eat food grown in city air, where some days smog and traffic-exhaust fumes feel like a heavy blanket that’s smothering your edible garden? : In last week’s installment of the Novice Gardener, we explored the toxicity of city soil (hello?
Photograph by Meredith Swinehart.
Greenhouse Gases
A rosemary bush and olive tree in a San Francisco city garden.
Why: Varying concentrations of gases can have myriad effects on plants, from changing a plant’s growing season to its ability to produce fruit, but such gases are not known to affect the plant in any way that might harm the health of the person eating it.
Photograph by Meredith Swinehart.
A fig tree growing streetside in San Francisco. Our discussion of Soil Contamination focused on heavy metals (specifically lead, a neurotoxin) and PAHs (carcinogenic particulates that result from incomplete combustion).
Airborne Particulates
Photograph by Meredith Swinehart.
Limes near a parking lot in San Francisco.
(For example, this study demonstrates lead absorption through leaves, but “this is a fairly extreme example; the experiment was downwind from a lead-battery recycling facility.”).
Washing produce in detergent before eating it has been demonstrated to remove surface deposits of lead-contaminated soil, according to a study published in Science of the Total Environment.