This is certainly a valid fear if you are traveling abroad, and one that should be considered. Many people will advise avoiding green leafy vegetables while traveling in an area where the water is to be avoided because of the amount of water that is needed to clean them and the knowledge that the water is not clean in and of itself. Some of the safest fruits and vegetables to eat are those that come "pre-packaged" by mother nature, ie, those that have a rind or shell that needs to be removed before eating. Examples include bananas, which are readily available in many locations and offer significant health benefits for many people in addition to usually being safe for consumption. Even better than writing off all vegetables, however, is speaking with your doctor
about what you can and cannot safely consume while you are traveling. He or she will usually be able to make specific recommendations for you prior to traveling based on the place to which you are traveling. Some cities may have specialized travel medicine doctors
who can do this, while in other cities your primary care doctor
will be your best bet. Please speak with your doctor.