WASHINGTON, DC -- February 7, 2003 -- The government has released a study of the U.S. population's exposure to 116 environmental chemicals that may cause serious harm or even cancer. These include chemicals in perfumes, deodorants, soaps, shampoos, nail polishes, insecticides, paints, adhesives, car care products, toys, and food containers, to name just a few common items.
The federal Centers for Disease Prevention and Control (CDC) conducted the survey by obtaining blood and urine specimens from a representative sample of 2,500 people for the years 1999-2000. Researchers measured the levels of various chemicals and their metabolites. A metabolite is a product produced by the body's breakdown of the original chemical compound. Blood and urine levels reflect the amount of the chemical in the environment that actually gets into the body.
The CDC selected each chemical based on the seriousness of its adverse health effects and the availability of accurate testing methods. These chemicals and substances included lead, mercury, cadmium, and other metals; cotinine (from tobacco smoke); phthalates (present in many plastics), dioxin, polychlorinated biphenyls (PCB's, present in industrial insulators and lubricants); phytoestrogens; and selected pesticides (including DDT), herbicides, and pest repellents. Some of these chemicals are discussed below. See the CDC web site for the full text of the report.
Cotinine from Secondhand Tobacco Smoke
The study showed that cotinine levels among adult nonsmokers decreased since a previous survey. Cotinine is a metabolite of nicotine that tracks exposure to environmental or secondhand tobacco smoke among nonsmokers. Higher cotinine levels indicate more exposure to secondhand smoke, which is considered a human carcinogen.
Cotinine levels in children were more than twice those of adults. Also, black people had cotinine levels that were more than twice the levels of whites.
The CDC comments: "Although efforts to reduce environmental tobacco smoke during the 1990's were successful, it remains a major public health concern." Indeed, secondhand smoke in the home may be putting children at risk at the same time as smoking is being phased out in many workplaces. Also, children may absorb more smoke from their environment than adults do, according to the CDC.
Lead Levels Declining, But Still Troubling
The percentage of children 1-5 years old with elevated lead levels was 2.2%, down from 4.4% in the early 1990's. Poor children in urban areas living in older homes with lead-based paint still remain at the highest risk for lead poisoning. This condition may result in seizures, mental retardation, and blood, kidney and nervous disorders. See Lead Paint Poisoning for more information.
Although Banned in 1973, DDT Still A Problem
An insecticide originally used against mosquitoes, DDT (dichlorodiphenyltrichloroethane) was banned in the United States in 1973. It is classified as a probable human cancer-causing agent.
DDE is a breakdown product of DDT. The substance was found in people 12-19 years old, even though they were born after the DDT ban went into effect. Also, serum blood levels of DDE were three times higher among Hispanics than among non-Hispanic whites or blacks. DDT exposure may continue to occur because of its persistence in the environment or in food, according to the CDC.
Phthalates: From Fragrances to Food Containers
Phthalates may cause birth defects and damage to reproductive organs. These plastic-like compounds are found in some cosmetics, perfume, soaps, deodorants, shampoos, car care products, food containers, and nail polish.
Differences in phthalate levels depended on age, gender, and the type of phthalate. For one type of phthalate, the levels were highest in those 6-11 years old; for another type the levels were highest in adult females. The CDC has not determined whether these gender and age variations are due to differences in exposure, body size, or metabolism.
Chlorpyrifos, a Common Pesticide
A very common pesticide, chlorpyrifos has been used on lawns, crops, and ornamentals; in pet flea collars; and as a termite treatment. The Environmental Protection Agency (EPA) is now phasing out chlorpyrifos as a termite treatment and restricting its use on some crops. Retail sales of chlorpyrifos for home use stopped in December 2001.
Chlorpyrifos affects the nervous system. Breathing or ingesting chlorpyrifos may result in headaches, blurred vision, and even seizures, coma, and death, depending on the amount and length of exposure (Agency for Toxic Substances and Disease Registry; Chlorpyrifos Fact sheet).
The CDC study checked the urine levels of a metabolite of chlorpyrifos in a sample group to establish a baseline level in the population. In future studies, the CDC will compare these baseline levels to new data to see the effects of restricting chlorpyrifos use. The report also noted that chlorpyrifos metabolite levels were twice as high in children as in adults.
Harmful Chemical Mixtures in the Body
The CDC study comes on the heels of another report about chemical contamination in the human body released by the Environmental Working Group (EWG) and Commonweal, two consumer groups concerned with health and the environment. The study was led by Mt. Sinai School of Medicine in New York.
Rather than testing for one particular chemical across the population, the Mt. Sinai group tested nine individuals for 210 chemicals. These subjects contained an average of 91 potentially harmful compounds, most of which did not exist 75 years ago. In total, the nine subjects carried 76 chemicals linked to cancer, and 49 chemicals in common with the CDC study participants.
"The CDC's work helps us assess exposure levels for each contaminant across the population; our study begins to document the complex reality of the human body burden--what we call the 'pollution in people'," said Jane Houlihan, EWG vice president for research (Press Release, January 30, 2003). "Both studies are long overdue, and both reveal disturbing gaps in scientific understanding of environmental contaminants and in our system of regulatory safeguards."
At Brayton Purcell, we are concerned about harmful chemicals and have handled many cases concerning exposure to beryllium, benzene, lead, and other toxic substances. If you have a medical injury that may be due to chemical exposure, please feel free to contact us to learn about your legal options.