We recently had the chance to eventually present the results obtained from experiments carried out on one selected Viennese urban garden “Paradeisgartl”.
The analysis of the urban garden samples taken in 2021 included the measurement of Pb mass fractions, which were found to be elevated in some spinach and radish samples in a previous project (Heavy Metal CityZen, https://heavymetalcityzen.com/). After a preliminary meeting in a smaller group on 6th of December 2022, a larger group meeting was organised on 1st of March involving most members of the ‘Paradeisgartl’ urban gardening association as well as members from MUL and BOKU (Johanna Irrgeher, Stefan Wagner, Simone Trimmel, Laura Feiner, Markus Puschenreiter). The data on tomato, radish, salad and soil samples was presented. All analysed food samples were below the Pb limit values allowed for food being sold within the EU (50 ng/g for fruits, 100 ng/g for roots and bulbs and 300 ng/g for leaves, according to the EU Commission Regulation 2021/1317 and calculated back to dry weight). Some of the washed salad samples came close to the limit and most unwashed salad samples exceeded the limit.
Considering the fact that the ‘provisional tolerable weekly intake’ (PTWI) of lead, which was commonly referred to in the past, has been abandoned by the WHO due to the high toxicity of Pb even in trace levels, it is advisory to avoid the uptake of lead as far as possible. However, the presence of Pb in natural soils cannot be completely avoided, whether food is grown in private gardens or bought at a market. The discussion revolved around what can be done to reduce consumption of Pb. Careful washing of vegetables and fruit, the use of compost and the preferential cultivation of fruit crops instead of leaf or root crops were discussed. We would like to thank the urban gardeners of Paradeisgartl once more for the fruitful collaboration and access to this interesting study site
