Differential uptake for dioxin-like compounds by zucchini subspecies

Area of Science:

• Environmental Chemistry
• Plant Science
• Toxicology

Background:

• Dioxin-contaminated soil poses risks to food safety.
• Zucchini (Cucurbita pepo) can accumulate environmental contaminants.
• Understanding plant uptake mechanisms is crucial for risk assessment.

Purpose of the Study:

• To investigate dioxin-like compound accumulation in different zucchini cultivars.
• To compare the bioconcentration factors (BCFs) of various dioxin-like compounds in zucchini.
• To explore the relationship between physicochemical properties and contaminant uptake in plants.

Main Methods:

• Cultivation of zucchini cultivars ('Patty Green', 'Black Beauty', 'Gold Rush') in contaminated soil.
• Analysis of 29 dioxin-like compounds, PCDD/Fs, and PCBs using WHO-TEFs.
• Calculation of toxic equivalent (TEQ) values and bioconcentration factors (BCFs).

Main Results:

• 'Black Beauty' and 'Gold Rush' showed significantly higher TEQ values than 'Patty Green'.
• Bioconcentration factors for dioxin-like PCBs were higher than for PCDDs and PCDFs across all cultivars.
• BCFs for PCDD/Fs correlated negatively with octanol-water partition coefficients, unlike PCBs in high-accumulating cultivars.

Conclusions:

• Zucchini cultivars exhibit varying capacities for accumulating dioxin-like compounds.
• Polychlorinated biphenyl (PCB) uptake in high-accumulating zucchini cultivars may involve unique, non-physicochemical mechanisms.
• Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) uptake appears primarily governed by their physicochemical properties, such as octanol-water partition coefficients.