I am including the following article in its entirety, especially since it talks about fruits and veggies that are SYSTEMICALLY contaminated and therefore cannot be made safe by washing, e.g., strawberries and potatoes.
Buy and plant wisely to avoid pesticides
Sophia Markoulakis, Special to The Chronicle
Saturday, November 19, 2005
The benefits of growing your own food are as many and varied as the disparities that exist between homegrown and conventionally grown produce. Some of us do it for the superior taste that comes from harvesting a newly ripened vegetable, some for the rewards of tending to our spiritual connection with nature, while others see it as a necessity because of the pesticides, herbicides and other toxins used in commercial agriculture.
In an ideal world, those of us with an astute taste for quality, an appreciation for the earth's precious cycles or a sensitivity to our growing exposure to harmful chemicals would have an outdoor space filled with abundant crops, and we would have time to tend to those crops. Until we reach that utopian state, we have to be selective with what we purchase and grow. Fortunately, it's still possible to foster a connection with the earth and grow delicious and safe produce with limited time and space.
The key to a compact and productive crop is to decide which produce to buy and which to grow. Of course, there's always the choice of buying only strictly organic produce, but it can be a costly option. More important, you'd miss out on the joy of gardening.
If food safety is your greatest concern, then consider the following list of the 12 most contaminated produce items an essential guide before planting.
The Environmental Working Group, a nonprofit, nonpartisan environmental watchdog organization dedicated to informing the public on human health and public safety issues, researched more than 100,000 U.S. government pesticide test results and found 192 pesticides on 46 of the most popular produce items. The most contaminated vegetables were celery, sweet bell peppers, spinach and potatoes. The most contaminated fruits were strawberries, red raspberries, apples, cherries, nectarines, peaches, pears and imported grapes.
Washing and peeling produce can remove some pesticide residue, but others on the list are exposed to pesticides internally, making it impossible to remove all toxins. If these items aren't high on your list of favorites, then consider the occasional organic purchase a wise use of time and space. If, on the other hand, you eat these items regularly, then it might be smart to grow them.
Permethrin, a government-listed carcinogen, is a neurotoxin insecticide routinely applied to commercial celery crops. The EWG found that 96 percent of celery tested had this and other chemical residues. It's also applied around more than 100 million homes as one of many chemicals in home-based pesticide products. Scary stuff.
Even with that data, you might still be intimidated by the prospects of growing celery, something that most of us have a habit of picking up at the store. Try growing celeriac or celery root instead.
Last fall I planted several organic roots from my local market and have enjoyed the shoots and leaves since. Given plenty of water from winter rains and summer irrigation, they offered two seasons of growth. Be sure to cut them back to 1 inch above the base of the root between seasons. Celery root is full of vitamins, and its deep green stalks and leaves impart a strong celery flavor to salads, soups and stews. Even just one or two roots will provide amply for a family of four.
In 2001, the U.S. Environmental Protection Agency published a memo explaining the uses of disulfoton, a toxic insecticide, on bell and pimiento peppers. This chemical, applied by injection at the shank of a 4- to 5-week-old plant, is commonly used to combat the green peach aphid. Though the memo states that the California Pepper Commission is interested in reducing pesticides in the industry, nearly 50 percent of their members applied this toxin.
Sweet pepper can be grown from seed started indoors in early spring or from readily available nursery plants (make sure the latter haven't been injected). Since sweet peppers are a warm-weather crop, consider taking some of your harvest at its peak and roast and peel the peppers for canning, pickling or freezing. Once roasted and peeled, some peppers can be sliced and layered with garlic, herbs and spices and canned, while others can be left whole for stuffing and frozen in airtight containers. Place a sheet of wax or parchment paper between each prepared pepper before freezing. Any scraps or broken pieces can be pureed and placed in ice cube trays and frozen for future sauces such as Harissa.
The EWG also found that 83 percent of spinach tested had 36 pesticide residues. That's a lot of chemicals for such a powerhouse plant.
Fortunately, spinach is easy to grow. And because of the Bay Area's mild climate, spinach can be grown almost year-round. Sow seeds in the fall or early spring in a sunny location and thin seedlings when they grow large enough to touch each other. Harvest the larger outer leaves of plants, leaving the smaller inner ones. If pests such as flea beetles plague your spinach, row covers might offer protection. Once the heat of summer hits and the plants bolt, be satisfied knowing that you enjoyed a healthy dose of spinach for a few months and a new harvest is only a couple of months away.
Because potatoes are tubers, they're exposed to toxins that seep into the ground, and unfortunately, peeling does little good. Fungicides are also routinely applied to them before they are planted, which is all the more reason to try planting organic "seeding potatoes."
When potatoes are planted in the spring, they provide multiple offerings. Flowering plants signal the production of small new potatoes hiding beneath the plant's canopy. Use these delicate tubers within a day of harvest. Allow the plant's foliage to die back and yellow before harvesting the remaining crop. To cure, spread potatoes in an even layer on a mesh screen, removing any dirt by hand. Place them in a dry, dark and airy place for a day or two and occasionally turn. Store in a cool, dry and dark location.
Due to their porous cell structure, strawberries and raspberries are perfect candidates for absorbing chemicals that are applied to them. But it's not just the topical chemicals that we need to worry about. As of January 2005, the EPA is phasing out the use of methyl bromide, a commonly used fumigant. This colorless, odorless gas is routinely applied to soil before planting to control a wide variety of pests. This highly toxic gas poses an acute risk to its applicators and depletes the ozone layer. The California strawberry industry has relied on the use of this fumigant for many years, representing roughly 35 percent of the total use in the state. Driscoll, a major berry grower, also acknowledges on its Web site the use of methyl bromide. Although this fumigant doesn't come in contact with its crop, when applied it does pollute the air with unsafe levels of toxicity.
Biological soil treatments are the safest and smartest way to discourage pests in strawberry fields. And, until the gaping loopholes of this phaseout can be restricted, seek out organically grown berries or try growing your own. A strawberry pot is an ideal place to plant your berries because it takes up vertical space in your yard. Wherever you plant them, make sure the crowns (the point where leaves sprout) are level with the soil. Water and mulch well.
Raspberries, with their invading root system, are not ideal for a small space. The training and pruning involved persuade most to seek them out at farmers' markets and roadside stands where someone else has done the work.
When it comes to the other fruits on the list, consider dwarf varieties of apple, cherry, nectarine, peach and pear trees that can be kept fairly compact with pruning and training. It might take several years for trees to produce a large enough crop to satisfy a summer's worth of indulgence when peaches, cherries and nectarines are in season. A better compromise would be to either join a Community Supported Agriculture program or patronize your local farmers' market.
As far as the top conventionally grown produce items least likely to be contaminated, they are asparagus, avocados, broccoli, Brussels sprouts, cabbage, cauliflower, eggplant, okra, onions, radishes, blueberries, grapefruit, plums and watermelon. By no means are these plants conventionally grown without the use of any chemicals. The Environmental Working Group's testing was done to find pesticide residues on items, and the mere nature and protective peel, skin and outer leaves of many of these low-residue items most likely kept the numbers down. The five fruits least likely to be contaminated are pineapples, mangoes, bananas, kiwi and papaya.
The greatest number of pesticides on a single sample of the least contaminated group was found to be three, compared with 10 found on spinach. Even though peeling and washing won't alter the ranking of these items since testing was done on items that were prepared for normal consumption, you should still wash all items thoroughly before eating.
Sophia Markoulakis is a food writer and recipe developer on the Peninsula. E-mail her at
home@sfchronicle.com.