Economic factors tend to drive farmers to market rather than accept the losses associated with this waiting period. This has resulted in pesticide exposure to consumers: a 1995 study by the Thai Division of Toxic Substances found that around 37 percent of vegetables, 20 percent of kale, 10 percent of cowpea and 73 percent of tangerines were contaminated with pesticide residues, consisting mainly of malathion, monocrotophos and methyl parathion