Environmental and health impacts of pharmaceuticals in radish crops irrigated with reclaimed water
摘要
The use of reclaimed water for crop irrigation can be an important route for pharmaceutical introduction into the food chain. This work aims to investigate the crop uptake, accumulation and translocation of 11 representative pharmaceuticals in radish crop through two realistic agricultural growing conditions (highland and fall radish). For this, radish crops were irrigated with three reclaimed water qualities: (i) WWTP effluent (named real effluent, RE), (ii) RE fortified with 5 µg/L of pharmaceuticals (named higher concentration, HC) and (iii) RE fortified with a concentration of pharmaceuticals 10 times lower than HC (0.5 µg/L, named medium concentration, MC). Results revealed that the pharmaceutical concentration in irrigation water does not play a role in radish quality. However, phytotoxic effects could appear at concentrations above 100 µg/L. A clear relation between irrigation water quality and uptake was obtained (RE < MC < HC). Pharmaceutical concentrations in radish leaves were higher than in roots in all cases. However, the total distribution percentages in radish tissues and soil were directly dependent on the environmental growing conditions (mainly attributed to evapotranspiration rates, ET). Octanol–water partition coefficient (log Kow) of each pharmaceutical was a critical factor in radish uptake, accumulation and translocation (optimal range 1–4), while organic carbon to water partition coefficient (Koc) played a key role in soil accumulation rates. The concentration levels of pharmaceuticals detected in the edible part of radish did not pose a risk to human health via dietary intake. However, irrigation with reclaimed water containing pharmaceuticals (mainly caffeine (CAF), carbamazepine (CBZ) and sulfamethoxazole (SMX)) could have a significant environmental impact for aquatic and terrestrial organisms. The link between risk assessment and future prospects was also discussed.
Graphical Abstract