THE LATEST ON BODY BURDEN
Findings and Recommendations
In a study led by Mount Sinai School of Medicine in New York, in collaboration with the Environmental Working Group and Commonweal, researchers at two major laboratories found 167 chemicals, pollutants, and pesticides in the blood and urine of nine adult Americans. Study results appear in a recently-published edition of the journal Public Health Reports (Thornton, et al. 2002) the first publicly available, comprehensive look at the chemical burden we carry in our bodies.
None of the nine volunteers work with chemicals on the job. All lead healthy lives. Yet the subjects contained an average of 91 compounds most of which did not exist 75 years ago.
TABLE 1: The chemicals we found are linked to serious health problems
* Some chemicals are associated with multiple health impacts, and appear in multiple categories in this table.
Scientists have not studied the health risks of exposures to complex chemical mixtures, such as those found in this study. For two-thirds of the chemicals found, many of which are banned, researchers have partially studied the extent to which these chemicals can harm human health. They have found that these 112 compounds can threaten nearly every organ in the body at every stage of life.
In total, the nine subjects carried:
TABLE 2: 167 compounds from seven chemical groups were found in the nine people tested
Source: EWG compilation of blood and urine analysis from two major national laboratories
The blood and urine from the nine volunteers were tested for 210 chemicals that can be divided into seven basic groups. Of the chemical groups tested, the most prevalent were those contained in 24 classes of semivolatile and volatile chemicals, with 78 detected. These classes include well-known industrial solvents and gasoline ingredients, such as xylene and ethyl benzene, that are used in a variety of common products like paints, glues, and fire retardants. The laboratory found 48 PCBs in the nine people tested. PCBs were banned in the United States in 1976 but are used in other countries and persist in the environment for decades. Their most common use was as an insulating fluid in electrical capacitors and transformers, vacuum pumps, and gas-transmission turbines. Lead was found in all 9 participants, and mercury was found in 8.
Health professionals are not trained to link health problems to an individuals chemical exposure, but it is increasingly evident that background exposures to industrial chemicals and pesticides are contributing to a portion of the steady increase in some health problems in the population. A number of significant health effects potentially linked to chemical exposures are increasingly prevalent:
Cancer. Between 1992 and 1999, cancer incidence increased for many forms of the disease, including breast, thyroid, kidney, liver, abdominal cavity connective tissue, skin and some forms of leukemia. The incidence of childhood cancer increased by 26 percent between 1975 and 1999, with the sharpest rise estimated for brain and other nervous system cancers (50 percent increase) and acute lymphocytic leukemia (62 percent increase). The incidence of testicular cancer also rose between 1973 and 1999 (NCI 2002). The probability that a US resident will develop cancer at some point in his or her lifetime is 1 in 2 for men and 1 in 3 for women (ACS 2001). Just 5 to 10 percent of all cancers are linked to inherited, genetic factors (ACS 2001). For the remainder, a broad array of environmental factors plays a pivotal role.
Major nervous system disorders. Several recent studies have determined that the reported incidence of autism is increasing, and is now almost 10 times higher than in the mid-1980s (Byrd 2002, Chakrabarti and Fombonne 2001, Yang, et al. 2000). The number of children being diagnosed and treated for attention deficit disorder (ADD) and attention deficit hyperactivity disorder (ADHD) has also increased dramatically in the past decade (Robison, et al. 1999, Robison, et al. 2002, Zito, et al. 2000). The causes are largely unexplained, but environmental factors, including chemical exposures, are considered a potential cause or contributor. Environmental factors have also been increasingly linked with Parkinsons disease (Checkoway and Nelson 1999, Engel, et al. 2001).
Defects of the reproductive system. Studies show that sperm counts in certain parts of the world are decreasing (Swan, et al. 2000, Toppari, et al. 1996). Scientists have measured significant regional differences in sperm count that cannot be explained by differences in genetic factors (Swan, et al. in press). Girls may be reaching puberty earlier, based on comparing current appearance of breast development and pubic hair growth with historical data (Herman-Giddens, et al. 1997). Incidence of hypospadias, a birth defect of the penis, doubled in the United States between 1970 and 1993, and is estimated to affect one of every 125 male babies born (Paulozzi, et al. 1997). The incidence of undescended testicles (cryptorchidism) and testicular cancer also appear to be rising in certain parts of the world (Bergstrom, et al. 1996, McKiernan, et al. 1999, Toppari, et al. 1996). Testicular cancer is now the most common cancer in men age 15 to 35 [NCI 2000]. Several studies have suggested links between developmental exposure to environmental contaminants and cryptorchidism or testicular cancer (Hardell, et al. in press, Hosie, et al. 2000, Toppari, et al. 1996, Weidner, et al. 1998).
Toxic effects do not require high doses
Hundreds of studies in the peer-reviewed literature show that adverse health effects from low dose exposures are occurring in the population, caused by unavoidable contamination with PCBs, DDT, dioxin, mercury, lead, toxic air pollutants, and other chemicals. The health effects scientists have linked to chemical exposures in the general population include premature death, asthma, cancer, chronic bronchitis, permanent decrements in IQ and declines in other measures of brain function, premature birth, respiratory tract infection, heart disease, and permanent decrements in lung capacity (EPA 1996, EPA 2000, Gauderman, et al. 2002, Jacobson and Jacobson 2002, Jacobson, et al. 2002, Kopp, et al. 2000, Longnecker, et al. 2001, NAS 2000, NTP 2002, Pope, et al. 2002, Salonen, et al. 1995, Sydbom, et al. 2001).
A growing body of literature links low dose chemical exposures in animal studies to a broad range of health effects previously unexplored in high dose studies. In low dose testing, scientists are using sophisticated techniques to measure subtle but important changes in the functioning of apparently undamaged organ systems, including alterations in immune function (such as antibody response), enzyme activity, hormone levels, cellular changes in tissues, neurobehavioral parameters, organ growth, and hormone and neurotransmitter receptor levels. Importantly, many low dose effects are detected following developmental exposure. These tests focus on the effects of chemical exposures comparable to those that occur in the general population, and far below the levels that have traditionally been considered safe based on the results of studies that feed lab animals high doses of a given compound. Using these protocols, scientists are finding that low doses of chemicals can be far more harmful than previously believed.
Low dose studies often identify toxic effects at levels far below those identified as the no effect level in high dose studies. For instance, through low dose studies of bisphenol A (BPA), a plasticizer chemical commonly used in dental sealants and plastic water bottles, scientists have revealed health effects at levels 2,500 times lower than EPAs lowest observed effect dose, with adverse outcomes ranging from altered male reproductive organs and aggressive behavior, to abnormal mammary gland growth, early puberty, and reduced breast feeding (Figure 1).
In the face of a powerful and growing body of literature linking low dose chemical exposures and health harms in the general population, the chemical industry continues to claim that low dose exposures to hundreds of chemicals simultaneously are safe. These claims, however, are nearly always based on a lack of scientific information on the toxicity of dose exposures, not on a definitive, scientific proof of safety.
High dose animal studies provide the foundation for federal exposure limits for contaminants in consumer products, drinking water, food, and air. Indeed, the nations regulatory system for chemical exposures is dependent on the notion that high dose studies will reveal all the toxic properties of a chemical being tested. We now know that this is not true. A number of factors, each of which can be as important as the exposure dose, determine a compound's toxicity:
There are other problems with the assertion that all low dose exposures are safe, or trivial, simply because they are small. The chief one being that the toxicity of mixtures is almost never studied. Current high dose studies, like those required for pesticides used on food, are conducted with purified single chemicals. In the real world, people are exposed to low dose mixtures of several hundred chemicals. Scientists do not understand the toxicity of these mixtures, and with few exceptions are not investigating them.
In the rare cases in which scientists have studied the effects of mixtures, they have found adverse health effects. In two recent studies scientists dosed laboratory animals with a mixture of 16 organochlorine pesticides, lead, and cadmium, each applied at its individual regulatory safe dose, and found that the animals developed impaired immune response and altered function of the thyroid, a gland that is critical for brain development (Wade, et al. 2002a, Wade, et al. 2002b).
Our body burden
Scientists refer to the chemical exposure documented here as an individuals body burden the consequence of lifelong exposure to industrial chemicals that are used in thousands of consumer products and linger as contaminants in air, water, food, and soil. There are hundreds of chemicals in drinking water, household air, dust, treated tap water and food. They come from household products like detergent, insulation, fabric treatments, cosmetics, paints, upholstery, computers and TVs, and they accumulate in fat, blood and organs, or are passed through the body in breast milk, urine, feces, sweat, semen, hair and nails. (Easton, et al. 2002, EPA 2002d, OECD 2002, Rudel, et al. 2001, Thornton, et al. 2000, USGS 2002).
We know that:
At least 20 major peer-reviewed scientific journals are devoted almost entirely to studies of health effects from chemical exposures. But despite the ever-growing volume of data on the nature and consequences of exposure to industrial chemicals, scientists and doctors cannot answer the most basic questions:
What health effects can be linked to the mixtures of industrial chemicals found in the human body?
Beyond a handful of chemicals, the answer is not known. The reason: there is no legal requirement to test most chemicals for health effects at any stage of production, marketing, and use.
Under the Toxic Substances Control Act (TSCA), chemical companies can continue making chemicals and putting new compounds on the market without conducting any studies of their effects on people or the environment. Some companies conduct rudimentary screening studies prior to production, but fewer than half of all applications to the EPA for new chemical production include any toxicity data at all. The government approves 80 percent of these applications with no restrictions, usually in less than three weeks. When data are provided, they are typically cursory in nature, because the government lacks the authority to request anything more than that. Eight of 10 new chemicals win approval in less than three weeks, at an average rate of seven a day. If there are no data, the government justifies approval with results of computer models that estimate if a chemical will harm human health or the environment (EPA 1997a, GAO 1994).
For chemicals that are already on the market, the EPA can request data only when it can substantiate that the chemical is causing harm, which it generally cannot do without the toxicity data it is seeking to request. In practice, this means that studies are required only after independent scientists have accumulated a body of evidence demonstrating potential harm, a process that typically takes decades.
What mixtures of industrial chemicals are found in the bodies of the general population in the U.S.?
Not known (even this study defines only a fraction of the chemicals in the nine people tested). The reason: beyond chemicals that are added to food or used as drugs, there is no requirement for chemical manufacturers to: disclose how their chemicals are used or the routes through which people are exposed; understand the fate of their chemicals in the environment; measure concentrations of their products in the environment or in people; or develop and make public analytical methods that would allow other scientists to gather information.
Companies sometimes develop methods to test for chemicals in the blood or urine of their workers, but they do not routinely disclose the methods or results to the government or the public. The government has spearheaded most of the limited testing that has been performed for the general population in studies funded by taxpayers. The governments studies have not kept pace with the ever-expanding array of new toxic chemicals. The countrys most comprehensive program for detecting industrial chemicals in the human body is run by a government program that reported on 27 chemicals in 2001 (CDC 2001). The chemical industry provided direct funding for none of this multi-million dollar effort, but instead paid their trade associations press office to educate the national media on the safety of industrial chemicals in the days following the governments report release. In their upcoming report on chemical exposures, CDC is expected to release information on 116 chemicals, or about 70 percent of the number identified in this study.
A few types of consumer products, such as cosmetics and home pesticides, must carry partial ingredient labels so consumers can make informed choices. Federal law, however, does not require the chemical industry to disclose ingredients in most household consumer products, including cleaners, paints and varnishes, and chemical coatings on clothing and furniture, or the so-called inert ingredients in pesticides, which are typically more than 95 percent of the retail product. The EPA has compiled a database of more than 1,000 chemicals they believe might be present in 11,700 consumer products, using data the Agency gathered from chemical encyclopedias, air sampling studies in the open scientific literature, and manufacturers. But the companies have classified the chemical recipes for 9,300 of these products as confidential business information.
The EPA attempts to track local exposures to chemical pollutants through two testing programs, one for tap water and another for ambient air. But testing captures only a small fraction of the chemicals a person is exposed to over the course of a day. At least 165 companies have manufactured the 167 chemicals found in the test subjects, marketing them under at least 265 trade and consumer product names. By contrast, some local and state air monitoring programs track only five chemical contaminants, most of them linked to automobile exhaust. Water suppliers test tap water for 70 contaminants, but the list excludes hundreds of chemicals known to contaminate public water supplies [e.g., (USGS 2002)].
Can an individual participate in a testing program to learn what industrial chemicals are in his or her body?
Not easily. In this study the laboratory costs alone were $4,900 per person. Scientists spent two years designing the study, gaining approval of the study plan from Mount Sinai School of Medicines Institutional Review Board, and recruiting subjects. People can request body burden tests through their personal physicians, but in general the methods used by available commercial labs are not sensitive, the available tests are limited, or both. The CDC lists availability of analytical methods as one of two major constraining factors in its national biomonitoring program (CDC 2002).
Conclusions and Recommendations
This study, combined with work from the Centers for Disease Control and Prevention, and a thorough review of the scientific literature reveals a ubiquitous and insidious pollution of the human population with hundreds of chemicals, pollutants, and pesticides. In large measure this is the result of a regulatory system that leaves the EPA with few tools to study the health effects or the extent of human exposure to the thousands of chemicals found in consumer products. The widespread use of poorly studied chemicals in the absence of any meaningful regulatory structure to control them has led to:
The chemical industry tightly controls the testing and the information flow on any issue related to their products. In general, the more recently a chemical has been introduced into commerce, the less scientists understand its toxicity, and the less likely it is that scientists will know how to test for it in people and the environment. The few chemicals or chemical families that have been well-studied are those for which scientists uncovered, often accidentally, environmental catastrophes that can include widespread pollution of the environment or human population.
Chemical companies are not required to disclose methods that could be used to test for their chemicals in the environment or the human body. Typically only after a compound has been on the market for decades, and has contaminated a significant portion of the environment, do independent scientists learn how to detect and quantify it. At that point, the CDC may choose to include the chemical in its national biomonitoring program. Even then there is no guarantee that the manufacturer will provide CDC with the methodology to detect it, or that the methods will be reliable. For example, three years after 3M announced that it was removing perfluorinated chemicals in Scotchgard from the market, chiefly because 3M found that the human population is widely contaminated with the chemicals, the CDC has yet to develop a method it considers reliable that would allow it to add the chemicals to its national biomonitoring program.
This situation is unacceptable.
At a minimum, people have a right to know what chemicals are in their bodies and what harm they might cause. The sole source of this information is the chemical manufacturers themselves, who historically have resisted all efforts to make basic health information on their products available to the public, regulators and independent scientists.
Without disclosure of information on the environmental fate, human contamination, and health effects of these chemicals, regulators cannot effectively prioritize efforts to reduce the health risks from the current contaminant load in the human population.
Regardless of whether or not Congress revises the nations laws or policies:
Revisions to the nations laws and policies governing chemical manufacture and use include the following provisions: