More than 175 million roses are sold in the U.S. in the days leading up to Valentine's Day. From seedling to shipping crates, a cocktail of chemicals protects those blooms.
Seventy percent of cut flowers sold in the U.S. are imported from countries where pesticide application is not as tightly regulated as it is on U.S. farms. A survey of 8000 workers in cut-flower plantations near Bogotá, Colombia found that workers were exposed to 127 different pesticides, 20% of which are banned in North America because they are considered extremely toxic and carcinogenic. Three of the pesticides are considered "extremely toxic" by the World Health Organization.
http://scienceblogs.com/seed/2007/02/everythings_coming_up_blood_di.php