Chemical hazards in leafy vegetables on the Dutch market

Abstract

A risk-based approach helps focus on the most relevant food safety hazards for human health to be included in a monitoring program. These can be identified based on information on the occurrence and severity of the hazards. For this purpose, a long list of hazards that may occur was established and prioritised based on frequency of detection and levels found. When this prioritised list is combined with information on the severity of a hazard (which is based on toxicological information) and Dutch consumption data, a short list of hazards can be compiled to include in a monitoring program. This report describes the results of a literature study performed to identify chemical hazards in leafy vegetables. The report is part of a series of reports on chemical hazards in food crops for which previously mushrooms, fruits and cereals, seeds and nuts were investigated. Long list of chemical hazards that might occur in leafy vegetablesA long list of chemical hazards possibly present in leafy vegetables was established by performing a literature study using pre-set search terms in Scopus and Web of Science. In total, 420 hits were evaluated for their relevancy resulting in 169 papers that were read in full and for which information was extracted in an Excel document. Additionally, a Google search was performed in four websites to obtain reports on the occurrence of chemical hazards in leafy vegetables, resulting in 31 relevant hits that were also summarised in the Excel document. Furthermore, for hazard groups that retrieved a limited number of papers, an additional literature search was performed resulting in 27 relevant papers. Based on the papers obtained, a long list of chemical hazards was extracted, which contained heavy metals, nitrate and nitrite, polycyclic aromatic hydrocarbons (PAHs), pharmaceuticals, personal care products and endocrine disrupting compounds, flame retardants, perfluor compounds, radionuclides, nanoparticles, plant protection products (PPPs), mycotoxins, plant toxins, cyanotoxins, processing contaminants, and cleaning agents and disinfectants. The majority of the papers described experimental studies on the possible uptake and accumulation of chemical hazards from the environment into leafy vegetables and most information was available for lettuce followed by cabbage and spinach. Intermediate list of prioritised chemical hazards in leafy vegetablesThose hazards that were frequently found in leafy vegetables, detected above (EU) legal limits, or reported to lead to exceedances of health based guidance values were included on the intermediate list.The following substances were included on the intermediate list from the heavy metals and elements section: aluminium, cadmium, copper and lead. These substances either exceeded the EU maximum limit (ML) or leafy vegetables were seen as major contributor to the substance's acceptable daily intake (ADI). Manganese (Mn) was identified as knowledge gap, since an experimental study, in which lettuce was hydroponically grown in Mn contaminated medium, resulte...