If pesticides are present on the surfaces of your fruits and vegetables, you can definitely remove a substantial amount of those surface pesticides through careful washing and light scrubbing. However, you cannot remove all of them nor can you remove pesticides that have been incorporated into the fruits and vegetables while they were growing.

From field to field and from year to year, the amount of pesticides used on different fruit and vegetable crops can vary greatly. However, some environmental organizations, like the Environmental Working Group (EWG) headquartered in Washington, D.C., have sampled large groups of fruits and vegetables to determine which non-organic foods most consistently contain pesticide residues (and how many different residues they contain). To see more details about the EWG pesticide measurement process, you can visit the EWG website at: http://www.ewg.org/foodnews/summary.

The worst offenders in the group have sometimes been tagged with the name, "Dirty Dozen Plus." In 2016, the Environmental Working Group (http://www.ewg.org/foodnews) released an updated report that identified foods in the conventional, non-organic food supply that contained the highest number of pesticide residues. The worst offenders are included in the list below.

These are presented in descending order in terms of pesticide residue frequency (the uppermost food contains pesticide residues on the most frequent basis, and the next food down contains pesticide residues at the second highest frequency, etc.):

• Strawberries
• Apples
• Nectarines
• Peaches
• Celery
• Grapes
• Cherries
• Spinach
• Tomatoes
• Bell Peppers
• Cherry Tomatoes
• Spinach

The "Plus" in the "Dirty Dozen Plus" reflects types of produce that didn't meet the traditional Dirty Dozen criteria yet were of special concern. While they may not have met traditional criteria to rank them in the top 12, the Environmental Working Group found that they were frequently found to contain residues of insecticides that are toxic to the human nervous system.

For the 2016 list, the "Plus" crops included:

• Hot peppers
• Leafy greens, such as kale and collard greens

On its website, the EWG reminds all of us that when it comes to fruits and vegetables, it would be most important for us to purchase organic when we are dealing with the "Dirty Dozen Plus" because these fruits and vegetables had the most problem with pesticide residues. However, on our World's Healthiest Foods website we go one step further and encourage you to purchase organically grown produce whenever possible. If organic options are not available, you're likely to lower your exposure to potentially harmful pesticides if you select from the "Clean 15" versus "Dirty Dozen Plus" end of the EWG spectrum of fruits and vegetables. But remember that all non-organically grown foods can differ dramatically in their pesticide residues and that your best bet is to choose from organically grown foods that cannot by law be treated with the vast majority of synthetic pesticides.