Uptake and Dissipation of Carbofuran and Its Metabolite in Chinese Kale and Brinjal Cultivated Under Humid Tropic Climate

Abstract

Carbofuran is an insecticide with a broad spectrum of activity and is relatively cheap. It is banned in many countries in the world; however, it remains widely used in Asia, Australia, and South America. Carbofuran is commonly used in vegetable farming in Malaysia and it is a legally registered pesticide. This study reports the uptake and dissipation of carbofuran and 3-ketocarbofuran in Chinese kale and brinjal under humid tropic field conditions. The residue profile in plants demonstrated an increase to a maximum, followed by a consistent reduction to a level below the limit of determination (<0.01 mg/kg) over the experimental period. The maximum residue concentration was attained on Day 3 for kale (1.16 mg/kg fresh weight) and Day 7 for brinjal (0.06 mg/kg fresh weight) after carbofuran application. In order to comply with the maximum residue level (MRL) of 0.01 mg/kg, the preharvest interval for kale and brinjal were suggested at 23 and 28 days, respectively. The preharvest interval indicates that carbofuran is not recommended for Chinese kale but it is acceptable for brinjal. The average half-life of carbofuran in soil is 1.24 days, shorter than the literature values reported based on temperate condition, indicating accelerated dissipation under tropical climate. The estimated half-life of carbofuran in leaves was shorter than that in fruits with kale leaves reported at 2.54 days whilst brinjal leaves and fruits recorded at 3.22 and 10.33 days, respectively.

Effect of cold storage on Carbofuran dissipation in Cabbages (Brassica Oleracea)

“…A similar study was carried out in kale and brinjal and half-life for leaves was also reported to be less than the fruits. The half-life of kale was found to be 2.54 days while as in brinjal leaves and fruits it was longer that is 3.22 and 10.33 days, respectively (Sim et al 2019).…”

Understanding the Degradation of Carbofuran in Agricultural Area: A Review of Fate, Metabolites, and Toxicity

“…Aubergines and other vegetables in Malaysia are often treated with carbofuran (Sim et al, 2019). It is an approved insecticide until May 2023, when it will be banned in agriculture (Pesticides Act 1974, 2021.…”

“…It was recorded that 187 vultures and hyenas died in 2004 after they scavenged bird carcasses containing carbofuran residue and its by-products (Plaza et al, 2019). Regardless of its severe effects, carbofuran is still broadly applied in Asia, South America, Australia, and Malaysia, which registered carbofuran as a legal pesticide (Sim et al, 2019).…”

Photodegradation of Carbofuran in Paddy Water Samples

“…The World Health Organization (2020) categorised carbofuran as unsafe, hazardous, and restricted its use. Carbofuran abuse has been a concern following numerous cases of carbofuran found in vegetables at levels exceeding the Maximum Residue Level (MRL) (Sim et al 2020). Additionally, carbofuran's secondary metabolites, notably 3-ketocarbofuran and 3hydroxycarbofuran, are also fatal.…”

“…Photolysis and hydrolysis yield secondary pesticide compounds that are more polar and stable than the parent. Some pesticides remained for months, contaminating the ecosystem (Sim et al 2020;Tien et al 2017). Therefore, research regarding carbofuran by-products is needed.…”