Fresh produce and their soils accumulate cyanotoxins from irrigation water: Implications for public health and food security. (December 2017)

• Record Type: Journal Article
• Authors: Lee, Seungjun; Jiang, Xuewen; Manubolu, Manjunath; Riedl, Ken; Ludsin, Stuart A.; Martin, Jay F.; Lee, Jiyoung
• Is Part Of: Food research international. Volume 102(2017)
• Page Start: 234
• Page End: 245
• Publication Date: 2017-12
• Subjects: Harmful algal bloom -- Food safety -- Food quality -- Crop productivity -- Human health risk; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2017.09.079
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: Microcystin (MC), a hepatotoxin that can adversely affect human health, has become more prevalent in freshwater ecosystems worldwide, owing to an increase in toxic cyanobacteria blooms. While consumption of water and fish are well-documented exposure pathways of MCs to humans, less is known about the potential transfer to humans through consumption of vegetables that have been irrigated with MC-contaminated water. Likewise, the impact of MC on the performance of food crops is understudied. To help fill these information gaps, we conducted a controlled laboratory experiment in which we exposed lettuce, carrots, and green beans to environmentally relevant concentrations of MC-LR (0, 1, 5, and 10 μg/L) via two irrigation methods (drip and spray). We used ELISA and LC-MS/MS to quantify MC-LR concentrations and in different parts of the plant (edible vs. inedible fractions), measured plant performance (e.g., size, mass, edible leaves, color), and calculated human exposure risk based on accumulation patterns. MC-LR accumulation was positively dose-dependent, with it being greater in the plants (2.2–209.2 μg/kg) than in soil (0–19.4 μg/kg). MC-LR accumulation varied among vegetable types, between plant parts, and between irrigation methods. MC-LR accumulation led to reduced crop growth and quality, with MC-LR persisting in the soil after harvest. Observed toxin accumulation patterns in edible fractions of plants also led to estimates of daily MC-LR intake that exceeded both the chronic reference dose (0.003 μg/kg of body weight) and total daily intake guidelines (0.04 μg/kg of body weight). Because the use of MC-contaminated water is common in many parts of the world, our collective findings highlight the need for guidelines concerning the use of MC-contaminated water in irrigation, as well as consumption of these crops. Graphical abstract: Highlights: Microcystin in irrigation water is a significant pathway for human exposure. Microcystin accumulated in crops and soil when grown with contaminated water. Crops lost their quality and productivity from microcystin exposure. Microcystin from irrigation water persisted in soil after crops were harvested. Consumption of crops grown with microcystin-tainted water poses a high health risk.