IE 11 is not supported. For an optimal experience visit our site on another browser.

Inside the FDA’s food safety lab

Scientists with the U.S. food-safety program monitor Americans’ favorite menu items — from Oreo cookies to tuna casserole, Budweiser to home-brewed iced tea — for a long list of chemicals, bad and good.
Betty Roberston of Belton, Mo., helps cook food in the basement kitchen of the Belton United Methodist Church on May 16. Volunteers cook the food which is then taken to the FDA food laboratory in Lenexa, Kan., for testing.
Betty Roberston of Belton, Mo., helps cook food in the basement kitchen of the Belton United Methodist Church on May 16. Volunteers cook the food which is then taken to the FDA food laboratory in Lenexa, Kan., for testing.
/ Source: The Associated Press

Thirteen cooks bustle in a steam-filled church kitchen, filleting catfish, frying lamb chops, roasting eggplant and stirring up soup — 250 pounds of food, all bought with federal tax dollars. Despite the tantalizing smells, nobody gets to eat these meals: Food and Drug Administration scientists will pull them apart, counting the nutrients and hunting for pesticides and other contaminants lurking in the food supply.

The is the backbone of the nation’s patchwork food-safety system, a massive yet little-known program that monitors Americans’ favorite menu items — from Oreo cookies to tuna casserole, Budweiser to home-brewed iced tea — for a long list of chemicals, bad and good.

And it hinges largely on one group of retired women, many in their 70s and 80s, in this rural spot of middle America. The women, all volunteers, gather in the tiny basement kitchen of Belton United Methodist Church on 16 Friday mornings a year to whip up feasts that land in test tubes instead of on dinner plates.

“Bacon, hot bacon,” comes the warning cry, and Margaret Kershaw sidesteps the sizzling tray passing by. She deftly cuts squishy beef livers and drops them into pans of oil, a pink gingham apron catching spatters.

“I get stuck with the liver,” she says with a little grin, because the other women “don’t like handling all that bloody stuff, you know.” The previous week she made coleslaw, cutting up “I don’t know how many pounds of cabbage.”

“Sometimes you think to yourself, ’Well, this is a waste of food,”’ says the briskly practical Kershaw, a retired nurse who emigrated from Britain shortly after World War II. “’Why do they need all those pans of bacon?’ ... But with all the tests they do, I guess they need that much.”

‘A picture of the American diet' 
The amateur chefs learned quickly not to add secret spices or ice the cakes too elegantly — the scientists neither taste nor admire before dissecting. The cooks must precisely follow FDA’s recipes, carefully mixing ingredients bought in different cities for a nationally representative sample of meals.

“It’s painting a picture of the American diet,” explains FDA chemist Chris Sack, who heads the pesticide-hunting branch of the program, called the Total Diet Study.

The U.S. food-safety system consists of a hodgepodge of agencies that mostly monitor fields, factories and shipping ports to ensure food makers and sellers follow quality and safety rules. When the Environmental Protection Agency checks pesticide levels, for instance, it tests a watermelon’s rind to see if the farmer sprayed the right kind and amount.

But people don’t eat the rind, so that testing says little about what chemicals we actually absorb.

Enter the Total Diet Study. It measures traces of chemicals in the average diet — levels about 1/20th of what other food-monitoring programs can detect — both in packaged foods and after consumers wash produce, mix up ingredients and properly cook a meal.

This year-in, year-out monitoring enables health officials to spot whether changes in food production or the environment affect food quality. In response, they can launch medical research, alter regulations or, if a problem is bad enough, recall a brand.

Bad contamination is very rare. But it happens:

A pesticide sprayer was sent to jail after FDA discovered he used an illegal bug-killer on 19 million bushels of oats headed for top-selling breakfast cereals.

Baby-food carrots were recalled because they absorbed lead while growing in an old apple orchard, where a lead-based fruit pesticide had seeped into the soil years earlier.

Insecticide was found in teething biscuits that were supposed to be organic, free of conventional chemicals.

And ever wonder why cereal always comes in plastic bags inside the box? Because this testing once uncovered PCBs leaching into wheat cereal by contact with its package, a box made of recycled paper that contained the cancer-causing pollutant.

Improving world food safety
So far this year, FDA has discovered traces of illegal pesticides on some grapefruit, tomatoes and collard greens, not enough for a health risk but a mystery yet to be solved.

Now the World Health Organization is urging other countries, even poor, developing ones, to adopt FDA-style testing so they can better target scarce resources to improve food safety. WHO’s top priority is learning more about so-called “persistent organic pollutants” — a class of chemicals, including the widely banned pesticide DDT, that remain in the environment for years without breaking down.

“Few countries have sufficient information on the exposure of their populations to the many chemicals that find their way, either intentionally or unintentionally, into food,” says the WHO’s Dr. Gerald Moy.

What started 40 years ago as checking a few foods for fallout from nuclear testing is today a $5 million canvassing of the food supply.

Four times a year, FDA employees enter grocery stores in three different cities with identical lists so long — 9 dozen eggs, 6 pounds of bacon, gallons of soda, cases of baby food — they dare not shop on crowded coupon days. With a few stops at fast-food restaurants to round out the menu, they can spend $3,000 per city.

They quick-ship purchases to an FDA laboratory in Lenexa, Kan., where workers sort the food, sending ingredients that need cooking on to the nearby Belton church ladies.

Rules of thumb
Inside the lab, giant blenders grind foods into mush so scientists can test for more than 300 pesticides, cancer-causing dioxins and industrial chemicals. This year, for the first time, they’re also hunting acrylamide, a possibly cancer-causing chemical formed when foods are cooked at high temperatures.

They count nutrients, too. Soon, FDA will learn how much folate, which prevents birth defects, women eat — the first evidence of whether recent fortification of bread and cereal is working well enough.

One rule of thumb: More processing typically means less pesticide residue. A raw peach, even washed and peeled, usually has more than a canned peach, says FDA’s Sack.

Second rule of thumb: The fattier a food, the more chemicals from the environment or processing can cling to it. With stick butter or margarine, for example, “you eat a bucketload of industrial compounds from that wrapper,” Sack says, adding, “They’re probably harmless.”

A painstaking search
Finding those traces is painstaking.

Donning safety goggles, Sack picks up a flask filled with smushed yellow cake. He adds in alcohols, solvents and salts — “pesticides hate salt” — and boils and siphons the now-watery mixture to leach out everything but the pesticide-containing fat.

A faintly yellow, oily skin rises to the top — those few bites of cake were 15 percent fat, thanks to the icing. A sophisticated machine then isolates chemical molecules, separating pesticide residue from fat and identifying it.

The cake harbored traces of methyl chlorpyrifos, a widely used insecticide found in virtually any wheat-containing product “unless it’s organic, and then there’s no guarantee,” Sack says.

Down the hall, FDA metals specialist Duane Hughes burns chocolate cake, hunting traces of lead. Metals such as brain-harming lead and mercury can sneak into food through polluted soil or water. Finding them requires destroying all of a food’s organic compounds, using acid and temperatures up to 880 degrees. A machine that measures the light absorption of atoms in the remaining ash tallies any metal.

Contaminant traces are mostly what the Total Diet Study records, levels usually far below federal safety limits — on the order of a part per billion, the equivalent of a kernel of corn in a silo 45 feet tall.

Why does the FDA bother?
As long as they’re legal, why bother counting so low?

“We learn every day that levels once thought safe are in question,” responds Hughes, the metals specialist. He notes that the government is about to lower by more than three-quarters the amount of arsenic allowed in drinking water.

And as levels of well-known pollutants like DDT and PCBs have plummeted in recent years, concern shifts to newer contaminants like volatile organic compounds — industrial chemicals such as the solvent benzene or petroleum byproduct toluene — found in more and more food.

Even traces add up over time, warns Richard Wiles of the Environmental Working Group, a consumer advocacy organization.

Using FDA’s findings, the environmental group is about to urge grocery stores to sell brands of peanut butter and other child-friendly foods that contain the fewest chemicals. Some brands contain 30 different contaminants, admittedly legal traces, Wiles says — but he contends parents would prefer peanut butter without any benzene or toluene.

“Can we clean up the production processes to get rid of them?” he asks. “It’s always better to reduce your exposure to these synthetic chemical contaminants when you can.”

‘Cooking for the federal government'
The Total Diet Study doesn’t hunt every threat. Food-poisoning bacteria, for instance, aren’t on the list — the government tries to tackle those bugs through a mix of different programs. That’s where FDA should put more focus, contends Caroline Smith DeWaal of the advocacy Center for Science in the Public Interest.

Another weakness: The program can trace the source of most foods if contamination is found, but can’t always track fresh produce — so finding which farmers used illegal pesticides this year is unlikely.

Still, “it’s an early warning system ... because they look at foods in a way nobody else does and find things nobody else finds,” Wiles says.

FDA’s church ladies must cook carefully to avoid altering the findings.

They use steel utensils that won’t leach metal into food, and a specially cleansed water supply to avoid contaminants from the local tap. They can’t just wipe off a dropped biscuit — it could have picked up lead from dust tracked in on the women’s shoes.

They shrug off the national importance of the sweaty work. When asked, they just say, “We’re cooking for the federal government.”

“It’s wonderful fellowship,” says Martha McKarnin as she fries pork chops.

And it earns the church $2,000 a year, more than traditional bake sales.

“You go home and have to take a shower — you smell,” McKarnin says, waving aside the smoke. But, “I’m an old farm gal, I’m used to hard work.”