Qat chewing and pesticides: a study of adverse health effects in people of the mountainous areas of Yemen.

Chewing qat leaves, Cathula Edulis, is now a very common behaviour among the people of the mountainous areas of Yemen. For about the past 20 years, in tandem with national development, qat chewing has been rapidly expanding, and the use of chemical pesticides in qat production has been increasing. In this study, the adverse effects on human health of qat chewing combined with pesticide use were investigated. Results of interviews and questionnaires showed that chewers of qat grown with few or no chemical pesticides and chewers of qat grown with chemical pesticides have considerably different subjective symptoms. Chewers of qat produced in fields where chemical pesticides are used regularly have more symptoms than chewers of qat produced in fields where chemical pesticides are rarely or never used. Chewers of qat produced with more chemical pesticides, in particular, experience acute adverse effects on the digestive system and chronic adverse effects such as body weakness and nasal problems. Farmers who chew homemade qat on which they spread chemical pesticides by themselves may have the highest health risks regarding the combination of qat and pesticides. It is concluded that chewing qat grown with chemical pesticides causes considerable adverse health effects in human beings.