Pesticide Use Safety of Vegetable Farmers Previously Assessed by Good Agricultural Practices in Khon Kaen Province, Thailand

Abstract

Nowadays, pesticide toxicity is a threat to health. The most imported pesticides are organophosphates (OPPs) of which accumulation in human body inhibits neurotransmission. Good agricultural practices (GAPs) are methods increasing safety in pesticide use. A preliminary survey revealed that vegetable farmers in Khon Kaen have been using OPPs and were assessed for GAPs once in more than 5 years, possibly that their knowledge, behaviors, and effects on safety might be changed. Therefore, this study was aimed to investigate: 1) levels of OPP residues in vegetables; and 2) relationship between levels of serum acetylcholinesterase enzyme (AChE) (an inverse proxy of serum OPP levels), and levels of knowledge and self-protective behaviors on pesticide use of  farmers by using questionnaires and finger capillary blood sampling.

          Results from randomized sampling showed that 74 farmers planted 3 types of vegetables (Chinese cabbage, Chinese kale, and water spinach). Seventy-four samples of vegetables were tested for OPP residues with the MJPK test kit and found that 85% were safe. Serum AChE levels in the farmers were normal (4.1%), safe (39.2%), risk (29.7%), and unsafe (27.0%). Results from knowledge and behavior questionnaires showed that all farmers had high scores on knowledge and 95.9% had high scores on self-protective behaviors. Serum AChE was not significantly correlated with levels of self-protective behaviors (Somer’s D symmetric = 0.066, P = 0.406). In conclusion, vegetables from GAPs-assessed farmers were safe. In long term; however, single-time training was not sufficient to reduce contamination in body. There should be periodically reassessed to maintain safety level in vegetable farmers.