1. Fluoride based pesticides such as cryolite (sodium hexafluoroaluminate) and fumigation products such as sulfuryl fluoride are commonly used in industrial farming. The more the fruit, vegetable, grain, dried fruit, seed or nut are sprayed with fluoride pesticides and/or fumigation products, the more the food will contain fluoride ions which cannot be washed off and will enter your body when you eat these foods or anything made with these foods.
    

2. The processing of foods, drinks, soups etc. with fluoridated water in fluoridated regions such as Ontario, Alberta and many US states results in these items containing significant amounts of fluoride. The levels of fluoride in these products vary depending upon a number of factors such as how much fluoridated water is used, the degree to which the volume of the product is diminished from cooking, dehydration etc., the amount of fluoride the foods originally contained from any treatment with fluoride pesticides and/or if they were grown in phosphate fertilizer.
    

3. The widespread use of phosphate fertilizer is another way fluoride levels have increased in conventionally grown foods. Compared to traditional and modern organic soils, phosphate fertilizer, which is made from phosphate rock, contains much higher levels of fluoride which can be absorbed into the foods growing in this fertilizer. Unlike pesticides and fumigation products which are sprayed directly on the foods, absorption of fluoride from phosphate fertilizer varies depending upon the plant. 

Tea plants, for example, are known for absorbing the highest amounts of fluoride from their soil. Tea plants deposit the absorbed fluoride in their leaves which is why teas are exceptionally high in fluoride. A cup of your average black tea will contain up to 5-times the amount of fluoride found in fluoridated water. The older the tea leaf, the higher the amount of fluoride, which is why bottled Ice Teas commonly contain up to 9-times the amount fluoride found in fluoridated water.

As demonstrated in the section Inconsistencies and Contradictions, US & Canadian dental and public health associations  acknowledge these other sources of fluoride when providing guidelines for safe daily fluoride exposure from toothpaste, mouthwash, prescription fluoride supplements, and baby formula which all result in lower daily fluoride exposure than fluoridated water.