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Scientists Rush to Study Genome of Lethal E. coli
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Preschoolers Exposed to BPA Through Food |
The worrisome, hormone-disrupting chemical BPA showed up in every urine sample taken from more than 80 preschoolers in two states, reported a recent study of kids, ages 2 through 5.
And even though BPA often appears in samples of dust, air and surfaces of objects, the new study found that most of the BPA that got into the little kids came from their food.
The researchers weren't able to determine which foods delivered the largest doses of BPA. But the chemical often appears in the linings of cans and in hard, clear polycarbonate plastic containers. Recent studies have also documented the migration of the chemical from packaging into foods.
NEWS: Food Packaging Harbors Harmful Chemicals
Levels of BPA detected in the kids' urine fell well below declared safe limits. Still, the findings suggest that caregivers could reduce the chemical burden of children they care for by paying more attention to the packaging their food comes in.
"Knowledge is power," said lead researcher Marsha Morgan, a research environmental health scientist at the Environmental Protection Agency in Research Triangle Park, N.C.
"I really believe that parents should be aware of containers that contain BPA or that microwaving can cause BPA to migrate when you heat up containers," she said. "They may want to use alternatives like glass or BPA-free containers."
The new results are the latest findings from an ongoing study on 257 preschoolers in North Carolina and Ohio. Over a 48-hour period in 2001, researchers originally took samples from dust, air, surfaces, food and drinks in the children's homes and daycares. They also collected urine samples.
Among other outcomes, the project has found that little kids are exposed to dozens of pollutants, including BPA. Many of those pollutants end up in their bodies. And even though adults live and work in the same spaces, children experience higher levels of exposure.
In the new study, Morgan and colleagues found BPA in the urine of each of the 81 kids whose urine they looked at, the researchers reported in the journal Environmental Science & Technology.
The scientists were also able to track the source of more than 95 percent of that BPA to the food that all 257 of the original kids were eating. Levels of BPA in solid foods were seven times higher than levels in liquids that the kids drank.
At the beginning of the study, the researchers had mixed together all of the food the kids ate over the two-day period, and they mixed liquids separately. That gave them the ability to compare foods with drinks, but they couldn't isolate the effects of any particular menu item. All of the foods had come from ordinary grocery stores.
According to the study, levels of the chemical in the kids' urine were 10 times lower than limits declared safe by the EPA. But some scientists have been strongly arguing that those limits are way too high, said Arnold Schecter, a public health physician at the University of Texas School of Public Health in Dallas.
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BPA may also interact with other chemicals in foods to multiply potential health risks, which are especially concerning for developing young brains and bodies. Schecter and colleagues have been systematically documenting the presence of pesticides, plasticizers, flame-retardants and all sorts of other chemicals in our food supply.
"If you were considering this one chemical alone, this amount would not exceed what is considered by some government agencies at this time to be an allowable or safe dose," Schecter said. "But of course, BPA is not the only toxic chemical being ingested. They not only interact with each other; they can cause similar endocrine disruption."
Because his work has shown that BPA levels are higher in canned foods than in other products, Schecter said that eliminating canned foods from kids' diets would go a long way towards reducing their exposure. It may also help to use glass or other alternatives instead of the hard, clear polycarbonate containers for food and drinks.
Some companies, such as the Eden Organic brand, already use BPA-free linings for their canned beans. In reaction to pressure from consumers, other companies may follow suit.
"This is avoidable," Schecter said. "Cans do not need to be lined with BPA, nor do bottles need to contain BPA."
Which Foods Are Most Likely to Get You Sick? |
As public health officials scramble to pinpoint the source of a deadly outbreak of a new strain of E. coli in Germany, a growing list of illnesses and advisories in Europe has sparked fears of food around the world.
For consumers, the outbreak also raises questions about which foods are riskiest to eat and why.
But ranking risk is difficult to do, experts say, partly because of the way statistics are tracked and partly because most cases of food-borne illness go unreported or uninvestigated. And any type of food can be a vector for dozens of varieties of infectious bacteria. Still, there are some trends.
NEWS: E. coli Outbreak Tied to Deadly New Strain
Among the worst offenders are undercooked meat, chicken and eggs. Fresh produce is also a major cause and a focal suspect for ongoing investigations in Germany. Public health agencies have warned people against eating raw sprouts, tomatoes, cucumbers and leafy greens that were grown in northern Germany.
In cases of contaminated produce, the fecal matter of animals is always ultimately to blame. Sometimes, farmers apply bacteria-laden manure directly to agricultural fields.
In other cases, irrigation water becomes contaminated. Wildlife may enter fields. Or human workers can contaminate food supplies during handling activities.
The first key to staying healthy, experts say, is to recognize what we're up against.
"We live in a world surrounded by bacteria," said Timothy Jones, state epidemiologist at the Tennessee Department of Health in Nashville. "Sometimes, epidemiologists joke about the fecal veneer that's everywhere. It's sort of a gross thought, but really, that's the world we live in."
Every year, one out of six Americans gets sickened from food that is contaminated with bacteria, according to the Centers for Disease Control and Prevention. The CDC documents more than 1,000 outbreaks each year for a total of 48 million people who develop symptoms ranging from nausea and abdominal cramping to fevers and severe diarrhea. Three-thousand people die annually from food-borne illnesses.
There are 31 known kinds of bacteria, viruses and other pathogens that infect people through food. But only a handful of agents cause the majority of diagnosed cases. (Many millions of cases have unknown causes.) Salmonella causes the most cases that are ultimately solved. E. coli 0157 causes the most severe outbreaks. Other players include norovirus, Listeria and Campylobacter.
Each type of infectious agent has its own preferred habitats. Campylobacter, for example, likes to live in chickens and other poultry, while E. Coli 0157 is happiest inside a cow.
That explains why ground beef has long been the top cause of E. coli 0157 infections, though improved regulations have reduced the percentage of cases caused by beef. Instead, produce has taken on a growing share of responsibility for spreading the bacteria.
Any type of fruit or vegetable can become contaminated with E. coli, Salmonella or other infectious microbes. But certain varieties have been most often linked to outbreaks, including sprouts, leafy greens, tomatoes, jalapeño peppers and melons.
Sprouts are particularly concerning because outbreaks usually start with contamination of the seeds, which are placed into warm water to make them sprout.
"You have an agricultural product with some risk of having E. coli or Salmonella in the seeds," said Kirk Smith, supervisor of the Food-borne Diseases Unit at the Minnesota Department of Health in St. Paul, who recommends that people avoid eating sprouts altogether. "And then you're incubating them in the same conditions that make bacteria grow."
BLOG: E. Coli: Mankind's Microscopic Minions
Once they're big enough to eat, sprouts have countless nooks and crannies that are impossible to wash well. Even if you could power-wash the crunchy salad-toppers, bacteria may become embedded inside the plant tissue. The same thing can happen with spinach, lettuce, tomatoes and other produce. In these cases, no amount of washing can remove the contamination.
Produce is also problematic because we eat it raw. It is easy to kill bacteria in meat and eggs as long as you cook them well and at high enough temperatures. But nobody boils a head of romaine before making sandwiches.
To reduce your risks of getting sick from your food, the CDC recommends washing hands in warm, soapy water for at least 20 seconds before cooking. Avoid cross-contaminating knives and cutting boards. And wash all produce thoroughly, even if it claims to be pre-washed.
The only foods Smith won't eat are sprouts, undercooked meat, raw milk, raw oysters and unpasteurized juices, like apple cider. Otherwise, he said, it's worth taking food-borne illnesses seriously, but it's better to eat fruits and vegetables than to avoid them out of fear.
"Things aren't perfect and they're never going to be perfect, but they're better than they've ever been in history," Jones said, adding that 3,000 deaths a year compared to billions of meals served every week adds up to a miniscule statistic.
"What kills most people in this country is obesity, heart disease and cancer," he said. "Vegetables and a healthy diet are very important for all of those things."
