Managing health risks in urban agriculture: The effect of vegetable washing for reducing exposure to metal contaminantsShow others and affiliations
2023 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 863, article id 160996Article in journal (Refereed) Published
Abstract [en]
A common, yet poorly evaluated, advice to remove contaminants from urban vegetables is to wash the produce before consumption. This study is based on 63 samples of chard, kale, lettuce and parsley that have grown near a heavily traf-ficked road in the third largest city in Sweden, with one portion of each sample being analysed without first being washed, and the other portion being subjected to common household washing. Concentrations of 71 elements were analysed by ICP-SFMS after a sample digestion that dissolves both the plant tissues and all potentially adhering parti-cles. The results show that the washing effect, or the fraction removed upon washing, varies significantly between el-ements: from approximately 0 % for K to 68 % for the n-ary sumation REEs. Considering traditional metal contaminants, the efficiency decreased from Pb (on average 56 % lost) to Co (56 %) > Cr (55 %) > As (45 %) > Sb (35 %) > Ni (33 %) > Cu (13 %) > Zn (7 %) > Cd (7 %), and Ba (5 %). A clear negative correlation between the washing effect and the different elements' bioconcentration factors shows that the elements' accessibility for plant uptake is a key control-ling factor for the degree to which they are removed upon washing. Based on the average washing efficiencies seen in this study, the average daily intake of Pb would increase by 130 % if vegetables are not washed prior to consumption. For the other contaminant metals this increase corresponds to 126 % (Co), 121 % (Cr), 82 % (As), 55 % (Sb), 50 % (Ni), 16 % (Cu), 8 % (Zn), 7 % (Cd) and 5 % (Ba). The advice to wash vegetables is therefore, for many elements, highly motivated for reducing exposure and health risks. For elements which are only slightly reduced when the vegetables are washed, however, advising should rather focus on reducing levels of contamination in the soil itself.
Place, publisher, year, edition, pages
Elsevier, 2023. Vol. 863, article id 160996
Keywords [en]
Urban gardening, Soil contamination, Soil-plant transfer, Soil particle adherence, Vegetable washing, Risk assessment
National Category
Environmental Sciences
Research subject
Natural Science, Environmental Science
Identifiers
URN: urn:nbn:se:lnu:diva-118830DOI: 10.1016/j.scitotenv.2022.160996ISI: 000908653400001PubMedID: 36539086Scopus ID: 2-s2.0-85144354171OAI: oai:DiVA.org:lnu-118830DiVA, id: diva2:1732208
2023-01-302023-01-302024-09-12Bibliographically approved