Posted by Margaret on 4/8/2008, 5:05 pm
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Overview: Biomonitoring and Body Burden
Scientists estimate that each person carries over 700 industrial chemicals within our bodies today. One way to measure actual levels of chemicals in the human body is through "biomonitoring;" measuring the levels of certain chemicals in blood, urine, breast milk, and other tissues. The U.S. Centers for Disease Control and Prevention conducts an assessment every other year and analyzes 148 different chemicals in the blood and urine of about 5,000 Americans. The Environmental Working Group (EWG) has conducted eight biomonitoring studies. One of the EWG projects found an average of 200 industrial chemicals and pollutants in the umbilical cord blood of ten infants.
Together, the industrial chemicals present in each of us add up to what is known as a "chemical body burden." Developing children are exposed to these chemicals while still in the womb and as infants through breast milk. We are exposed through the air we breathe, drinking water, and through the foods we eat. Everyday products in our homes and workplaces provide additional sources of contamination without our consent.
Although certain persistent and toxic chemicals have been banned in the United States, such as the pesticide DDT and industrial insulator PCBs, they are still detected in our bodies and the bodies of children born after these chemicals were banned. Chemicals used in everyday products such as food and beverage containers also leach toxic chemicals that contaminate our bodies. Although these chemicals are associated with adverse health effects in laboratory animals, it is difficult to ascertain long-term health effects in people-everyone reacts differently to chemicals based on age, genetics, gender, lifestyle, and nutrition. To complicate matters, level, length, frequency, and timing of exposure all play into how chemicals affect human health. Recent scientific studies have explored the effects of some chemicals such as bisphenol-A, atrazine, and phthalates at very low doses in animal studies, but most chemicals are not tested for possible effects in the extremely low dose range. Recent research has shown that adverse health effects in laboratory animals can occur at levels of exposure that are far below currently accepted lowest observed adverse effect levels (LOAEL), the levels used by the EPA to calculate "safe" doses for humans. In some cases, these effects are not seen at higher levels of exposure.
Logically, we have always assumed that the "dose makes the poison," and it is difficult to understand how tiny amounts might have any effect. However, we can understand more about how industrial chemicals at low levels can be biologically active when we consider chemicals used for medical purposes. Many prescription drugs aimed at addressing a host of medical conditions can cause the intended biological effects at doses similar to the low levels found in humans through biomonitoring. Hormones have the capacity to act at extremely low levels to regulate development, reproduction, immune function, and many other biological systems at parts per million or parts per billion as well. It is not surprising that industrial chemicals also mimic hormones in this capacity.
Alaska Community Action on Toxics has coordinated biomonitoring projects to investigate levels of industrial chemicals in Alaskans.
ACAT's Biomonitoring Work
In 2001 and 2003 at the request of the villages of St. Lawrence Island,, Alaska Community Action on Toxics in collaboration with scientists from the State University of New York collected blood samples from 130 people from the villages of Gambell and Savoonga (from families associated with and not associated with the Formerly Used Defense Site at Northeast Cape) on St. Lawrence Island, Alaska to determine the levels of polychlorinated biphenyls (PCBs) in their blood. We also conducted analyses to establish the difference between exposure to PCBs from atmospheric transportation and from local sources. The results showed that on average, the Yupik people on St. Lawrence Island have elevated levels of PCBs compared to the general public in the continental United States. The results also suggested that the formal military site at Northeast Cape may contribute to the PCB exposure level of the families that use the area. The results of this study have been published in the International Journal of Circumpolar Health (volume 64(4)
ages 322-335) and the project was supported through a grant from the National Institute of Environmental Health Sciences.
Our most recent biomonitoring project tested 35 Americans from seven different states, including five Alaskan participants. Released in November 2007, the project resulted in the report: Is It In Us? Chemical Contamination in our Bodies-Toxic Trespass, Regulatory Failure and Opportunities for Action, and documents the results of blood and urine testing for the presence of three classes of chemicals: phthalates, bisphenol A and polybrominated diphenyl ether (PBDEs). The project results found all three classes of toxic chemicals in every person tested. The report can be found here or at www.akaction.org or www.isitinus.org.
Is It In Us? Biomonitoring Project: Chemicals of Concern
Phthalates: Used in soft PVC (vinyl) toys, shower curtains, flooring, and medical equipment; also binds scents and color in cosmetics and air fresheners. Research links phthalates to feminized genitals in baby boys, reduced sperm quality, asthma and rhinitis in children, and shorter pregnancy duration. Click here to learn more about phthalates.
Bisphenol A (BPA): Used in some plastic water and baby bottles, dental sealants, and the resin linings of metal food cans. Discovered as a synthetic estrogen, human and animal studies link BPA to reduced sperm counts and other reproductive impacts, cancer, obesity, and miscarriages. Click here for more information on BPA.
PBDEs (polybrominated diphenyl ethers): Flame retardants added to the plastic cases of televisions and home electronics, automobile components, foam cushions, upholstered furniture and other textiles used in the home and workplace. Studies link PBDE exposure to impaired memory, learning, and behavior in laboratory animals. Click here to learn more about PBDEs.
For more information on the biomonitoring project Is It In Us? or for information on these chemicals, please contact Alaska Community Action on Toxics or visit: www.akaction.org.
News in Alaska: Current Legislation
HB 271 Would ban the use of PBDEs!
Representative Andrea Doll (D-Juneau) introduced a bill this legislative session that would ban the use of PBDEs in Alaska. HB 271, would ban the manufacture and sale in Alaska of the class of flame retardants known as PBDEs that are used in fabrics and plastic casings pf computers and other electronic devices. Studies show that exposure to PBDEs negatively affects learning and memory functions of young children, cause thyroid problems, and reduces sperm count. PBDEs are increasingly shown to accumulate in the environment, fat tissues, and breast milk. Though they do work as fire retardants, equally good alternatives exist. Current research shows that PBDEs generate toxic fumes (dioxins and others) when burned, and are a health hazard to firefighters and others exposed to fires.
Along with banning PBDEs, HB 271 also empowers Alaska State Department of Environmental Conservation (ADEC) to ban other flame retardants if they determine they are harmful to public health or the environment. It also would require ADEC to develop a list of "chemicals of concern" that are recognized as carcinogenic, neurotoxic, developmental toxicants, or are bioaccumulative. ADEC will then develop an action plan to reduce and phase out those chemicals of concern.
To support HB 271 or for more information, contact Alaska Community Action on Toxics at (907) 222-7714 or info@akaction.net, or the office of Representative Andrea Doll at: Rep_Andrea_Doll@legis.state.ak.us or (907) 465-3744.
SB 288 & SJR 18: Protecting our Children
Senator Bill Wielechowski (D) introduced both a bill and a joint resolution that are aimed at protecting children's health from toxics. SB 288, "Pesticides/Broadcast Chemicals in Schools" would reduce exposures of children to pesticides. If passed, it will require that schools use least toxic alternatives to pesticides and provide public notice if pesticides are used. Pesticides are linked to a wide range of health effects including asthma, learning disabilities, and cancer. Children are more susceptible to pesticide exposure than adults. SJR 18, "Child Product Safety" would request that the President and Consumer Product Safety Commission to strengthen regulations on the chemicals that are used to manufacture children's toys and other products. Currently, there is no government agency testing the chemicals used in children's toys and manufacturers are not required to disclose information about toxic chemicals in toys.
To support SB 288 and SJR 18 or for more information, contact Alaska Community Action on Toxics at (907) 222-7714 or info@akaction.net or contact the office of Senator Wielechowski at: Senator_Bill_Wielechowski@legis.state.ak.us or (907) 465-2435.
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