Potential Neuropoison Could Be in Our Food
Long after a potentially neurotoxic flame retardant is off the market, it could linger in our food chain.
One of the most comprehensive analyses yet of human exposure to PBDEs, or polybrominated diphenyl ethers, shows that the chemical — long used in everything from computers to sleeping bags — enters humans through their diets, not just their household.
“The more meat you eat, the more PBDEs you have in your serum,” said Alicia Fraser, an environmental health researcher at Boston University’s School of Public Health who headed the new study, published this month in Environmental Health Perspectives.
PBDEs are chemical cousins of polychlorinated biphenyls, or PCBs, which are known to cause birth defects and neurological impairments. PCBs were banned throughout the world by the mid-1970s, when PBDEs were gaining popularity as flame retardants. PBDEs were soon found in most plastic-containing household products.
By the late 1990s, trace amounts of PBDEs had been found in people all over the world, with the highest exposures measured in the United States. Researchers became nervous: Low doses caused neurological damage in laboratory animals, and the highest human PBDE levels were found in breast milk.
Whether PBDEs posed an immediate threat to humans was uncertain. Direct testing is unethical, and population-wide epidemiological studies are difficult to run. But there’s enough reason for concern that the European Union banned two of the three most common PBDE formulations in 2004.
The Environmental Protection Agency, which in January admitted that it lacked the ability to establish basic standards of chemical safety, has not followed suit, but three states — California, Washington and Maine — have banned PBDEs since 2007. Many manufacturers have either stopped or plan on stopping their use.
“They are persistent in the environment. They don’t get broken down. Therefore, it takes a really long time for the contamination to leave our environment and our bodies,” said Fraser. “Even though we don’t know the health effects at this point, most people would want policies that would stop us from being exposed to them.”
But though well-advised, these bans won’t eliminate the threat. Most PBDE exposure research has focused on how people can absorb it from dust and other indoor sources that would ostensibly be eliminated once PBDE-containing products were discarded. Much less attention has been paid to PBDEs in food.
Fraser’s team analyzed biological samples from 2,000 people, provided by the U.S. Centers for Disease Control and Prevention. The same data was used in 2004 to establish baseline estimates of PBDE exposure in Americans, but that study didn’t look for patterns in food consumption. Fraser’s team found that PBDE levels were 25 percent higher in meat-eaters than vegetarians.
Though the channels of food contamination by PBDEs haven’t been conclusively established, it’s possible that “the old products are being moved to landfills, and PBDEs could enter the environment that way,” said Fraser. Earlier this year, the National Oceanic and Atmospheric Administration announced that PBDEs were present in all U.S. coastal waters and the Great Lakes, with the highest levels found near urban and industrial areas.
That PBDEs would be highest in meat products makes sense, as the chemicals accumulate in fat, and it wouldn’t be hard for PBDEs to enter their feed and water.
Fraser suggested that the United States adopt chemical regulations similar to those in the European Union, which in 2007 mandated that chemicals be thoroughly tested and proven safe before used. That’s the opposite of the U.S. system, where chemicals are assumed to be safe until it’s proved otherwise.
“The industry is finding new products to use as flame retardants, and we don’t know the health and safety implications of those products either,” said Fraser. “We need to test the health and safety implications of products before they go into use, not after.”
US: Black Obesity Rates 10% Higher than Whites’
Recent figures show obesity is more prevalent among African-Americans and Hispanics, indicating racial and ethnic disparities in US obesity rates.
The overall obesity rate in the US is reported to be about 25.6%. The condition is also reported to be more prevalent in women in all three racial and ethnic groups.
According to the report published in the Morbidity and Mortality Weekly Report, non-Hispanic blacks (35.7%) followed by Hispanics (28.7%) and non-Hispanic whites (23.7%) had the highest prevalence of obesity in the US during the years 2006 and 2008.
The report also revealed that none of the US states have reached the federal government’s Healthy People 2010 goal, which aims to reduce the obesity rate among adults to amounts as low as 15%.
Differences in behavior as well as physical and social environments are possible factors contributing to the disparity in obesity rates in these individuals.
“The disparities here are easy to explain,” said David Katz, adding that “They’re associated with poverty, less education, areas where you can’t find fresh fruits and vegetables, and some cultural differences.”
Scientists concluded that an effective public health strategy program, which is a combination of policy and environmental changes, is required to overcome obesity and the reported disparity.
Swine flu: 100,000 UK cases a day by August
More than 100,000 people could be diagnosed with swine flu every day by the end of August, the government said, announcing that the disease can no longer be contained in the UK.
A Commons statement by the health secretary, Andy Burnham, marks a watershed in the spread of the flu. No more schools will be closed, unless forced to by the lack of staff or if the pupils are especially vulnerable. Families and people in contact with those with flu will not be given preventative antiviral drugs.
The new policy of treatment for those with diagnosed illness, rather than containment, has already begun in the hotspots – chiefly London, Birmingham and Scotland.
The change of tactic is the predicted response to the swelling number of people infected. There are now 7,447 diagnosed cases in the UK, but the number is doubling every week. If they continue in this way, said Burnham in his statement, “we could see over 100,000 cases per day by the end of August”. He later stressed that the figure “is a projection. It is not a fact. This is how the disease could develop and we don’t know.”
Those sorts of numbers would put a heavy burden on the NHS, which is already feeling the strain in some areas. The new strategy will help keep those with possible symptoms out of GP surgeries.
People who think they may have flu are now being advised to go online and check their symptoms on the NHS website or call the swine flu information line, on 0800 1 513 513. Anyone still concerned after that should phone their GP, who can provide a diagnosis over the phone. If swine flu is confirmed, they will be issued with an authorisation voucher, which a “flu friend” can take to an antiviral drug collection point, which may be a pharmacy or a health centre.
But health officials in Scotland doubt the virus will spread dramatically across the UK, as it seems to have peaked in Scotland, which saw the first big outbreaks, and the first two deaths in Europe.
The rapid spread of the virus has slowed down in Paisley, which suffered the second largest outbreak, and it has disappeared in Dunoon, where a coachload of football fans were infected. In Glasgow, until recently the worst affected area of the UK, infection rates have stabilised. After infection rates peaked at 111 confirmed cases on 25 June, the rate in Scotland has remained steady at an average of about 60 new cases a day over the last week. There is no evidence that infection rates in Scotland, where the virus first arrived in late April, were doubling.
Dr Harry Burns, Scotland’s chief medical officer, said he was “now optimistic that sometime over the next few weeks, the rate of transmission will begin to slow down” [in Scotland].
It was entirely possible, he added, that the outbreaks elsewhere in the UK would also slow down in a matter of weeks.
The fatality rate also appears to be low. In the UK, only three people – all with significant underlying health problems – have died out of 7,447 confirmed cases. Health experts believe more people have caught swine flu but shown no symptoms.
In the United States, the official figures show 27,725 Americans have contracted H1N1, with 127 deaths. The Centres for Disease Control and Prevention, in Atlanta, estimates that a million Americans may have caught swine flu but not been to a doctor, suggesting that fatality rates are as low as 0.012%, Burns said.
The European Centre for Disease Prevention and Control reported on Thursday that of 69,177 cases which had been detected worldwide, only 328 people had died – a fatality rate of 0.47%.
However, Sir Liam Donaldson, the chief medical officer, said that it was not yet possible to work out the death rate from the virus, “given the unreliability of the data”, but that it would become clearer in the coming months.
The first batches of vaccine will arrive in August.
Although the UK has ordered enough for the entire population, it will arrive in batches. At-risk groups would get it first, said Donaldson: those especially vulnerable because of diseases which have compromised their immune systems or affect their breathing, such as asthma.
New flu strains cannot be eradicated. They simply become part of the seasonal flu mix. Donaldson said that swine flu could continue to cause extra deaths for five years. “We will need the vaccine in years to come,” he said.
From The Guardian