An annual survey of vegetables and fruits found high toxic contamination on 41% of sampled vegetables and fruits, and the problem was bigger at retail stores than wet markets.

The survey by the Thailand Pesticide Alert Network (ThaiPAN) and its partners - local health officials, farmers and residents - collected 286 samples of popular vegetables and fruits from retail stores and wet markets in Bangkok, Chiang Mai, Khon Kaen, Sa Kaeo, Yasothon, Chanthaburi, Ratchaburi and Songkhla for toxic contamination tests, ThaiPAN coordinator Prokchol Ousap told a news conference in Nonthaburi on Wednesday.

The samples were sent for standard laboratory tests in the United Kingdom, and high toxic contamination was found in 41% of them, she said.

Vegetables with the highest contamination were Chinese mustard greens, kale, hot basil, parsley, chilli and cauliflower. Fruits with the highest percentages of harmful contamination were tangerines, rose apples, guavas and grapes.

Unsafe contamination was found in 33.3% of imported fruit and 48.7% of local fruit. Unhealthy contaminants were found in 44% of samples from retail stores, and 39% of samples from wet markets, Ms Prokchol said.