Evaluating contamination exposure rates in different Urban Agriculture (UA) practices

Conference poster, 2020

Introduction: Urban Agriculture (UA) is instrumental in instilling a degree of self-sufficiency in food production inevitable for a resilient and sustainable city. Nevertheless, urban soil can be a substantial source of contamination due to previous, ongoing or even adjacent land-use like heavy traffic, and consumption of fresh produce grown on such could be an added exposure pathway for the urban population. These concerns lead many countries to follow strict regulation for gardening in urban areas bracketing it with residential use accentuating the exposure risks. But there are many UA practices with varying degree of user involvement and management; the prevalent ones taking place well-out of the residential periphery. However, there exist neither a definitive soil screening guideline that refers to such variations of UA practices nor studies on UA scenarios to modify the existing risk models.

Methods: This study identifies different UA scenario and compares the contamination exposure to highlight the difference of risk in them. An exposure risk model is created combining with UA scenario sensitive parameters to test on five different practices; house garden, allotment garden, neighbourhood greenspace, meadow orchard and arable land. The scenario exposure data is to be collected from surveying different UA practice group in Gothenburg, Sweden.  

Results: The preliminary result with elicited data shows that practices with residential or extensive use such as house garden, neighbourhood greenspace and arable land predictably have high risk.  More common UA uses such as allotment gardens are much less risky when exposed to the same concentration of contamination while dropping to almost none for meadow orchards.

Conclusion: Retrofitting abandoned, and derelict lands allow UA to find a place in the competitive urban land market. More knowledge on the exposure from soil contamination from different UA practices would provide more options to bring back obsolete land in use.