polybrominated diphenyl ethers (PBDEs) | Healthy Child Healthy World

Description

Polybrominated diphenyl ethers (PBDEs) are bromine-based compounds used as flame retardants in plastic and foam consumer products � primarily electronics, furnishing, and insulation used around wires and in the home � since the 1970s. There are as many as 209 individual PBDE compounds, and they often occur in mixtures. The three most widely used mixtures in consumer products are deca-BDE, octa-BDE, and penta-BDE. Structurally, PBDEs are very similar to polychlorinated biphenyls (PCBs) and polybrominated biphenyls (PBBs), which were also once used as flame retardants and insulators. Both PCBs and PBBs are banned or severely restricted in most countries due to health and environmental effects.

There is little information on the health effects of PBDEs in humans. Animal studies have shown that PBDEs affect thyroid hormone functions and can impair the developing central nervous system and brain. There is also evidence that PBDEs may be more toxic when combined with PCBs. The toxicity of PBDEs varies by type due to their differing chemical structures.

Until recently, brominated flame retardants were considered safe. However, in 1999, Swedish researchers discovered much greater amounts in human breast milk than had been detected twenty-five years earlier. Subsequent studies have found an even sharper rise in U.S. women, leading some researchers to conclude that PBDE levels in North Americans are 10 to 20 times higher than in Europeans and are doubling at a rate of every four to six years. This has raised concern among many scientists and environmental health advocates.

PBDEs easily enter the surrounding environment. Like other organohalogen compounds, they can persist in the environment for decades, travel far, and accumulate in fat tissues of animals. As a result, PBDEs also have been found � at surprisingly high levels � in wildlife, soil sediments and sewage sludge. PBDE levels tend to rise up the food chain, with the highest levels in large, predatory animals and fish.

PBDEs can cross the placenta, exposing the fetus. Infants are exposed to PBDEs through breast milk. Children take in PBDEs from animal foods and house dust, and possibly from gases that vaporize from household products containing PBDEs. These will persist in their bodies though adulthood.

The following products usually contain PBDEs: computers, television sets, mobile phones, electronics and electrical items, automotive equipment, construction materials, polyurethane foam mattresses, cushions, carpets, upholstered furniture, and draperies, among others. PBDEs typically constitute between 5 and 30 percent of the product�s net weight.

As early as the mid-1990s, European companies started voluntarily phasing out PBDE production in favor of alternative flame retardants. The European Union banned penta-BDE in 2004 and will phase out deca-BDE by 2006. In European countries where PBDE use has been discontinued, the level of PBDEs found in humans is dropping.

But in the U.S., there are no federal regulations restricting use of PBDEs, even though body burdens here appear to be the highest in the world and are still rising. In 2003, California voted to ban penta- and octa-BDE by 2008. A few months after, the sole American manufacturer of these two chemicals agreed to take them off the market by the end of 2004. But, deca-BDE, the most widely used PBDE, will continue to be used in the U.S. A number of states have enacted or are considering legislation to regulate or ban PBDEs.

Health Effects

Immediate Health Effects

If SWALLOWED, polybrominated diphenyl ethers (PBDEs) is Slightly Toxic
If ABSORBED THROUGH SKIN, polybrominated diphenyl ethers (PBDEs) is Slightly Toxic
If INHALED (SNIFFED OR BREATHED IN), polybrominated diphenyl ethers (PBDEs) is Slightly Toxic

Longterm or Delayed Health Effects

Neurotoxin = Can harm brain and central nervous system
Suspected Endocrine Disruptor = May interfere with, mimic or block hormones

Other

In animal studies, exposure to PBDEs harmed the developing brain and nervous system, causing deficits in learning and memory and behavioral alterations.
PBDEs disrupt thyroid hormone in animals. Studies have found that they affect the thyroid gland and decrease levels of T4, a hormone essential to proper nervous system development, in the bloodstream. Exposure to PBDEs in the womb and through nursing have also caused thyroid effects in animals.
Cancer. The U.S. Environmental Protection Agency has classified deca-BDE, the most commonly used PBDE, a possible carcinogen. This is based on increases in liver tumors in exposed laboratory animals. The agency has listed penta- and octa-BDEs as unclassifiable as to carcinogenicity, most likely because of lack of data.
Other animal studies have found effects on the liver, immune system, and reproductive system, including delays in onset of puberty.

How Exposures Occur

DUST and POSSIBLY GASES from PBDE-CONTAINING PRODUCTS

Children may inhale, touch or ingest PBDEs in dust and possibly also gases released from PBDE-containing products. These include polyurethane foam furniture and mattresses (penta-BDE), and computers, television sets, cell phones, and other electrical and electronic appliances (deca-BDE). PBDE-containing products release PBDE particles into indoor air, as shown by findings of high levels of PBDEs in household dust and in residues collected from window surfaces. PBDE levels appear to be higher indoors than outside.

IN BREAST MILK

PBDEs are found in human breast milk. There is a potential for infants to ingest PBDEs. However, the benefits for babies from breast feeding outweigh the risks of PBDE exposure. Breastfed babies are healthier than those who are bottle-fed; they experience fewer allergies, respiratory illnesses, and skin problems. In its 1997 policy statement, Breastfeeding and the Use of Human Milk, the American Academy of Pediatrics highly recommends breast feeding for all infants for one year.

IN FOOD

Children, as well as adults, can ingest PBDEs in high-fat foods such as fish, meat, and eggs, since PBDEs accumulate in the fatty tissues of animals. Farmed salmon, which are fed a diet high in fatty fish oils, have been found to contain higher PBDE concentrations than wild salmon.

PRENATAL

PBDEs appear to pass readily through the placenta, as shown by similar PBDE levels found in the blood of mothers and their newborns. Mothers will have accumulated a significant load of PBDEs throughout their lifetime. They are slow to leave the body, sometimes persisting for decades.

Significant Statistics

In 2001 alone, North American industries used approximately 73 million pounds of PBDEs, accounting for almost half the world market.

Birnbaum, L. et al. “Brominated Flame Retardants: Cause for Concern?” Environmental Health Perspectives, Vol. 112, No. 1 (January 2004).http://ehp.niehs.nih.gov/members/2003/6559/6559.html

Over the past 30 years, body concentrations of PBDEs have doubled every 4 to 6 years. PBDE concentrations in North Americans are 10 to 20 times higher than they are in Europeans.

In a recent study measuring PBDE concentrations in breast milk of 20 first-time mothers across the U.S., PBDE concentrations were on average 75 times higher than levels in recent European studies.

Mothers’ Milk: Record levels of toxic fire retardant found in American mothers’ breast milk. Environmental Working Group, September 2003.http://www.ewg.org/reports/mothersmilk/

Ninety percent of electrical and electronic appliances contain brominated flame retardants.

Bromine Science and Environmental Forumhttp://www.bsef.com

As much as 30 percent of the weight of polyurethane foam consists of penta-BDE flame retardants.

Solutions

How to detect polybrominated diphenyl ethers (PBDEs)

Consumers can expect to find PBDEs in nearly all electronics and items made of polyurethane foam, such as furniture, cushions and carpet pads. The following products usually contain PBDEs: computers, television sets, mobile phones, electronics and electrical items, automotive equipment, construction materials, polyurethane foam mattresses, cushions, carpets, upholstered furniture, and draperies, among others.

Most products, with the exception of some computers and computer components, are not labeled as made with PBDEs.
Some computer companies list the toxic components found in their products in the product’s manual. These companies are complying with a voluntary international certification and labeling standards program based in Sweden known as TCO. Approved products must not exceed the approved levels of heavy metals, brominated and chlorinated flame retardants, and CFCs (freon). The standards also deal with energy efficiency, electrical and magnetic fields, and fire safety.

Many manuals can be downloaded on the manufacturers’ websites. You can also find TCO-approved products on TCO’s website.

How to minimize exposure to polybrominated diphenyl ethers (PBDEs)

Reduce consumption of high-fat fish, meat and dairy products, and choose low-fat versions. PBDEs accumulate in animal fats. Fish appear to be the most contaminated food source, although more testing is needed.

Instead, choose foods that are low in fat, such as skim and low-fat dairy products, skinless chicken breast meat, turkey. Small, low-fat and non-predatory seafoods—such as shrimp, tilapia and flounder—are also less likely to contain to contain PBDEs, as are salmon that are wild-caught instead of farmed. (All salmon labeled “Atlantic” are farmed.)
Because PBDEs are added to so many consumer products, and contamination is so pervasive in American homes, it may be impossible to avoid some exposure, measurements of PBDEs in household dust suggest.
Minimizing exposure to household dust may reduce PBDE exposure:

--Vacuum carpets and upholstered furniture at least twice weekly. Open windows while vacuuming to disperse dust in vacuum’s exhaust. Use multi-layered vacuum bags instead of regular single layer bags, and use a vacuum with a high-efficiency, or HEPA, filter. Do not use a bagless vacuum, as dust will be released when the collection container is removed for emptying.

--Damp-wipe dusty surfaces and mop floors weekly, especially in homes with small children, who spend much of their time on the floor.

Alternatives

Choose fish, meats and dairy products that are low in fat, since the PBDEs accumulate in animal fat.
Look for TCO-approved computers, displays, keyboards and printers. TCO is a voluntary international certification and labeling standards program based in Sweden dealing with environmental and ergonomic issues related to computers and other products.

TCO-approved computers, displays, keyboards and printers contain very little PBDEs, as the standards strictly limit the allowable amount. The exception to the restriction on PBDE use is the circuit board, as there is no suitable alternative at this time.

For information on the standards and products that are TCO-approved, see TCO’s website. (There is a drop down menu to change the language of the site in the upper right corner.)
Furniture maker IKEA, auto manufacturer Volvo, and electronics manufacturers Intel, Philips, IBM, Dell, and Ericsson no longer use PBDEs in their products. Most Hewlett-Packard computer monitor housings are PBDE-free. Motorola, Panasonic, NEC, Hitachi, Sony, Samsung and Toshiba have all taken significant steps towards phasing out toxic flame retardants from their products.

Mattresses now made in the U.S. are unlikely to contain foams treated with PBDEs, according to industry experts. See Rest Easy on a Safe Bed.
Where possible, choose natural fiber (wool, cotton, hemp) carpet pads, bedding, cushions and upholstered furniture. Wool is naturally flame-retardant. Several companies make wool carpet padding, furniture cushions, and mattresses, though purchasing a mattress free of chemical flame retardants may require a doctor’s prescription.

For More information

Books, articles, factsheets and reports

Toxic Flame Retardants (PBDEs). Toxic-Free Legacy Coalition, February 2004.

http://www.watoxics.org/content/pdf/PBDEsFactSheet.pdf

In the Dust: Toxic Fire Retardants in American Homes. Environmental Working Group, May 2004.

http://www.ewg.org/reports/inthedust/summary.php

ToxFAQs for Polybrominated Biphenyls and Polybrominated Diphenyl Ethers (PBBs AND PBDEs). Agency for Toxic Substances and Disease Registry, September 2002.

http://www.atsdr.cdc.gov/tfacts68.html