Hydroponic vegetables have been found to be more contaminated with chemicals than vegetables grown with soil, the Thailand Pesticide Alert Network (Thai-PAN) revealed on Monday.
After announcing the shock result of its testing on 30 hydroponic vegetable samples from across the country, Thai-PAN – along with the BioThai Foundation – urged producers and distributors of hydroponic vegetables and concerned agencies to come up with measures to reduce the use of chemicals in their cultivation, establish a standard to limit contamination, and ensure food safety for consumers.
Thai-PAN coordinator Prokchon Usap said that 19 of the 30 samples tested, or around 63 per cent, were contaminated with an unsafe level of chemicals, while three samples were found to be contaminated with chemicals at an acceptable level. No contamination was found in the other eight samples.
Prokchon pointed out that the hydroponic vegetables were found to be more toxic than traditionally grown vegetables, as an earlier test on the latter by Thai-PAN had showed that around 54.4 per cent were contaminated with a high level of chemicals.
“People often believe that hydroponic vegetables are safer from chemical contamination than traditionally grown ones, but our examination proves this belief wrong, as soil-less-grown vegetables are also found to contain 25 kinds of chemical used in agriculture,” she explained.
“An even more concerning finding from our test is that 17 of the 25 kinds of chemical are absorbent chemicals, which are very hard to clean out,” she added.
The coordinator also revealed that some kinds of hydroponic vegetables such as Chinese kale, lettuce and spinach were found to be contaminated with a very high level of nitrate up to 6,000 milligrams per kilogram of vegetable, but there was still no official recommendation about such contamination.
BioThai Foundation coordinator Kingkorn Narintarakul na Ayutthaya said there was a misunderstanding among the public that organic vegetables, which do not use chemicals during the entire production process, were similar to hydroponic vegetables, but Thai-PAN’s testing had proved this to be wrong.
“Hydroponic-vegetable producers should lower their chemical use, as in reality growing hydroponic vegetables can be more easily managed than the traditional growing method, while the Agriculture Department should set up measures to control the chemical use in hydroponic vegetables to ensure consumer safety,” Kingkorn suggested.