Uptake and accumulation of antimicrobials, triclocarban and triclosan, by food crops in a hydroponic system

Abstract

Commonly used in personal care products, triclocarban (TCC) and triclosan (TCS) are two chemicals with antimicrobial properties that have recently been recognized as environmental contaminants with the potential to adversely affect human health. The objective of the study described herein was to evaluate the potential of food crops to uptake TCC and TCS. Eleven food crops, grown in hydroponic nutrient media, were exposed to a mixture of 500μgL(-1) TCC and TCS. After 4weeks of exposure, roots accumulated 86-1,350mgkg(-1) of antimicrobials and shoots had accumulated 0.33-5.35mgkg(-1) of antimicrobials. Translocation from roots to shoots was less than 1.9% for TCC and 3.7% for TCS, with the greatest translocation for TCC observed for pepper, celery, and asparagus and for TCS observed for cabbage, broccoli, and asparagus. For edible tuber- or bulb-producing crops, the concentrations of both TCC and TCS were lower in the tubers than in the roots. Exposure calculations using national consumption data indicated that the average exposure to TCC and TCS from eating contaminated crops was substantially less than the exposure expected to cause adverse effects, but exceeded the predicted exposure from drinking water. Exposure to antimicrobials through food crops would be substantially reduced through limiting consumption of beets and onions.