Mancozeb Residue on Tomatoes in Central Uganda

Area of Science:

• Agricultural Science
• Environmental Chemistry
• Food Safety

Background:

• Mancozeb, a dithiocarbamate (DTC) pesticide, is widely used in Uganda for crop protection.
• Non-systemic DTC pesticides play a crucial role in managing fungal diseases in agriculture.

Purpose of the Study:

• To investigate mancozeb concentrations on tomatoes in Central Uganda.
• To identify areas for reducing human exposure to mancozeb residues.
• Focus on both farm and market samples to assess exposure pathways.

Main Methods:

• Analysis of tomato samples for mancozeb residue.
• Quantification of residue as carbon disulfide (CS2).
• Utilized gas chromatography-mass spectrometry (GC-MS) for precise measurement.

Main Results:

• Detectable mancozeb residue found in all analyzed tomato samples.
• Mean concentrations: 1.03±0.28 mg/kg on farms, 0.77±0.49 mg/kg in markets.
• Farmers applied 3-6 times the recommended mancozeb dosage and used a shorter pre-harvest interval (1-2 days vs. 3-7 days).

Conclusions:

• Observed farming practices pose a significant risk of dithiocarbamate exposure.
• Farmers and consumers are likely exposed to mancozeb residues due to improper application.
• Need for improved agricultural practices to ensure food safety and reduce pesticide exposure.