Nuts and seeds are ideal snacks. They provide vitamins, minerals and quick energy without unhealthy fat or empty calories. Although the nutmeat or seed is protected by a shell or fruit, unless they are raised organically they are treated with synthetic chemicals just as other non-organic crops. Look for the USDA organic seal on nut and seed packages.
Many consumers want raw organic nuts and seeds. The USDA pasteurization laws require nut growers and processors to steam-heat raw almonds to pasteurize them. If you want raw organic almonds, you can still buy unpasteurized almonds in person, directly from the grower.
Endosulfan, a pesticide that is banned in most countries but still legal in the U.S. and India, is used on non-organic cashew trees. It is highly toxic to humans and animals, and washes into waterways where it harms aquatic life. Endosulfan is a hazard to farm workers as well as people who live near farms where it is used. According to grinningplanet.com, it affects the central nervous system, and causes damage to kidneys, liver and testes. Organic cashews are grown without the use of any poisonous chemicals, including endosulfan.
Non-organic pistachios may be treated with phosmet, a Class II pesticide. Studies at Cornell University indicate chronic toxicity in rats from long term, small doses of phosmet. A two-year mouse study showed increased liver tumors and carcinoma, and the pesticide is considered a category C carcinogen. Safe, organic pistachios are not exposed to phosmet or any other synthetic chemicals.
Peanut plants are legumes, with seeds that develop underground. Sixwise.com explains that because they have direct soil contact, pesticides and chemicals can be very concentrated in peanuts. Peanuts grown in the southeastern U.S. are exposed to humid conditions that create a greater risk of insect, mold and fungal infection. The poisonous aflatoxin, a carcinogenic mold that affects peanuts, transmits easily in humid environments. The National Sustainable Agriculture Information Service reports that most U.S. organic peanuts are grown in the dry Southwest. While all peanuts must be checked for aflatoxin, it is rarely found in Southwestern peanuts. Look for Valencia cultivars of peanuts. These cultivars were bred for New Mexico's growing conditions, and they produce premium organic peanuts.