Challenges in assessing the health risks of consuming vegetables in metal-contaminated environments

• Published in: Environment international 2018-04, Vol.113, p.269-280
• Main Authors: Augustsson, Anna, Uddh-Söderberg, Terese, Filipsson, Monika, Helmfrid, Ingela, Berglund, Marika, Karlsson, Helen, Hogmalm, Johan, Karlsson, Andreas, Alriksson, Stina
• Format: Article
• Language: English
• Subjects: Adult; Agaricales - chemistry; Agricultural Science; Arsenic; Arsenic - analysis; arsenic speciation; Cadmium; Cadmium - analysis; contaminants; Contaminated sites; Crops, Agricultural - chemistry; Dietary Exposure - analysis; Environmental Monitoring; Environmental Science; Environmental Sciences; Exposure; Food Contamination - analysis; food crops; Food Science; Fruit - chemistry; garden vegetables; glassworks sites; heavy-metals; homegrown vegetables; human; Humans; Jordbruksvetenskap; Lead; Lead - analysis; Livsmedelsvetenskap; Medicin och hälsovetenskap; Metals, Heavy - analysis; Miljövetenskap; potentially toxic elements; Risk Assessment; soil; Soil Pollutants - analysis; Vegetable; Vegetables - chemistry; waste-water
• ISSN: 0160-4120; 1873-6750; 1873-6750
• DOI: 10.1016/j.envint.2017.10.002

A great deal of research has been devoted to the characterization of metal exposure due to the consumption of vegetables from urban or industrialized areas. It may seem comforting that concentrations in crops, as well as estimated exposure levels, are often found to be below permissible limits. However, we show that even a moderate increase in metal accumulation in crops may result in a significant increase in exposure. We also highlight the importance of assessing exposure levels in relation to a regional baseline. We have analyzed metal (Pb, Cd, As) concentrations in nearly 700 samples from 23 different vegetables, fruits, berries and mushrooms, collected near 21 highly contaminated industrial sites and from reference sites. Metal concentrations generally complied with permissible levels in commercial food and only Pb showed overall higher concentrations around the contaminated sites. Nevertheless, probabilistic exposure assessments revealed that the exposure to all three metals was significantly higher in the population residing around the contaminated sites, for both low-, median- and high consumers. The exposure was about twice as high for Pb and Cd, and four to six times as high for As. Since vegetable consumption alone did not result in exposure above tolerable intakes, it would have been easy to conclude that there is no risk associated with consuming vegetables grown near the contaminated sites. However, when the increase in exposure is quantified, its potential significance is harder to dismiss – especially when considering that exposure via other routes may be elevated in a similar way. [Display omitted] •Pb, Cd and As concentrations in vegetables were below permissible limits.•The intake of local vegetables alone did not render an intake above TDIs.•Hence, vegetable consumption around the contaminated sites may seem safe.•Significantly higher exposures were, however, assessed for the contaminated sites.•These results highlight the significance of establishing a reference baseline.