Meat, Poultry are Major Sources of PBDE Exposure
US - Red meats and poultry have been found to be major sources of exposure to polybrominated flame retardants, known as PBDEs, in the US. The conclusion follows research just published in Environmental Health Perspective by Fraser and co-workers.
23 July 2009
5 minute read
People who eat meat and poultry have significantly higher levels of common flame retardants compared to vegetarians, according to a summary of Fraser and co-authors' paper in Environmental Health News. The findings indicate that food may be a more important source of the contaminants, known as PBDEs, than previously thought. PBDEs are omnipresent in the environment This is the first large-scale study to examine the contribution of red meat and poultry to dietary PBDE body burden in the US.
Methods used in the study
Data collected as part of 2003-2004 National Health and Nutrition Examination Survey (NHANES) were examined for a correlation between food eaten and blood levels of PBDEs. A randomised sample of 2,337 participants that were 12 years or older supplied dietary information via a 24-hour food recall list and a food frequency questionnaire. Food was assigned to one of the following groups: poultry, red meat, dairy, egg, seafood and non-animal products.
The blood levels of ten PBDEs (BDE-17, 28, 47, 66, 85, 99, 100, 153, 154 and 183) were measured. Only five with the highest measured levels (BDE-28, 47, 99, 100 and 153 – all components of pentaBDE) and their sum were compared to the participants' diets.
Results were adjusted statistically for age, sex, race or ethnicity, income, body mass index (BMI), and socioeconomic and demographic variations.
Main findings
Serum levels of five different PBDEs were associated with eating poultry. People who more poultry had higher levels of the PBDEs. Poultry fat was the greatest contributor to the body burden of PBDEs.
Red meat intake was associated with two of the measured PBDE levels. Seafood and dairy were not associated with any changes in the PBDE levels in serum.
Vegetarians had 23-27 per cent less PBDEs circulating in their serum as compared to meat-eaters.
The highest levels of PBDEs were found in males, the youngest age group examined (12-19 years old), the poor and the underweight (subjects with lowest BMI).
Implications
The major source of human exposure to PBDEs has been assumed to be via contaminated dust at work or in the home. Some recent findings have pointed toward other possible sources, including diet.
This study indicates that food is a more important route than previously thought.
A number of scientific studies have suggested that PBDE levels in food supplies are rising. These studies, however, have been limited by small sample sizes and by small geographic scope.
The greatest strength of this study is the large sample number that the researchers used for their analysis. Based on their comprehensive research, poultry and red meat are major sources of dietary PBDE exposure in the US. Identifying which foods are most contaminated is a major step in limiting public exposure.
Since this study lacks information about the household exposure of the subjects to PBDEs, scientists refrain from commenting on the relative contribution of dietary exposure to overall body burden of flame retardants. The authors conclude that comprehensive studies that include dietary, household, and geographic data will be needed to determine the contribution of each factor more accurately.
PBFEs and human health
Polybrominated flame retardants, known as PBDEs, are suffused into consumer products to suppress fires, save lives and lower the economic burden of fire accidents. Electronics, plastics, textiles, car interiors and many other products now contain the chemical fire suppressors.
The long-lived chemicals are not fixed into materials, so they slowly leak out of the products and into the environment. More chemicals are released as the products age.
In North America, meat, poultry, dairy and fish are known to be contaminated with PBDEs. The food comes into contact with PBDEs during processing and through packaging materials.
Most human exposure is thought to be through food and dust, but which contributes the most to human exposure is not known.
In the last few decades, as PBDE use increases, levels of PBDEs in human tissue have increased significantly. Americans and Canadians have 10 to 20 times higher levels of PBDEs than people in Japan or Europe. The highest levels have been detected in US children between the ages of two and five years.
The first scientific evidence about the toxicity of several types of PBDEs surfaced in mid 1980s. European regulations began to limit PBDE use in the 1990s and took tightened restrictions further in 2004; by 2008 several US states had taken action against at least one of the PBDEs. Two types of PBDEs are no longer manufactured in the US because of health concerns. Exposure continues, however, both because products that contain them are still in use and because the chemicals themselves are highly persistent. Consumer goods that have entered the waste stream, for example, in landfills, continue to release PBDEs. Sewage sludge can be heavily contaminated
PBDEs accumulate in the liver, kidney and thyroid gland and are known endocrine disruptors. Chronic exposure and elevated levels lead to disruption of estrogen and thyroid systems. Animal and epidemiological studies link PBDE exposure to several types of reproductive and nervous system impairments.
The health effects associated with exposure to PBDEs are a major public health concern. Children may be especially vulnerable to their toxic effects because of their developing nervous systems.
Reference
Fraser A.J., T.F. Webster and M.D. McClean. 2009. Diet contributes significantly to the body burden of PBDEs in the general US population. Environmental Health Perspective doi: 10.1289/ehp.0900817.
Other resources
Birnbaum, L. and D.F. Staskal. 2004. Brominated Flame Retardants: Cause for Concern? Environmental Health Perspectives 112:9-17.
National Health and Nutrition Examination Survey. Centers for Disease Control and Prevention.
Polybrominated diphenylethers (PBDEs). US Environmental Protection Agency
Reducing your exposure to PBDEs in your home. Environmental Working Group.
Schecter A., T.R. Harris, N. Shah, A. Musumba and O. Päpke. 2008. Brominated flame retardants in US food. Molecular Nutrition and Food Research 52:266-72.
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