The National Toxicology Program (NTP) is an interagency program within the U.S Department of Health and Human Services and is located in Research Triangle Park, North Carolina. NTP’s research and testing programs provide data addressing a wide variety of issues important to public health. NTP works to safeguard public health by identifying the effects of chemicals used in everyday items and at what level of exposure they have the potential of becoming hazardous to humans. NTP has attracted controversy because of its policy of allowing some industries to self regulate their own products and because of its extensive use of animals for testing.
NTP was established in 1978 by Joseph J. Califono, Jr., Secretary of Health, Education and Welfare. The program was created as a cooperative effort to coordinate toxicology testing programs within the federal government, strengthen the science base in toxicology, develop and validate improved testing methods and provide information about potentially toxic chemicals to public health.
In May 1984, National Cancer Institute , scientists headed by Dr. Robert C. Gallo, Jr., and funded by the National Institutes of Health, uncovered strong evidence that variants of a human cancer virus called HTLV-III are the primary cause of acquired immunodeficiency syndrome (AIDS). In 1997 scientists determined the complete genome sequence of the E. coli bacterium, a laboratory workhorse. This accomplishment has given researchers the tools needed to understand fundamental questions of biological evolution and function. NTP researchers also discovered that exposure to lead has the potential of causing permanent damage to a child’s brain and nervous system. In 2007, researches determined that a chemical referred to as nexavalent chromium caused cancer in laboratory animals when consumed in drinking water. In
NTP brings together three main agencies:
NIEHS/NIH researches diseases that are linked to environmental exposures, for example, asthma, autism, breast cancer and Parkinson’s disease. Among the chemicals or factors in the environment that may cause harmful health effects are: dioxins, electric and magnetic fields, endocrine disruptors, lead, mold, ozone and pesticides. People can also be exposed to hazardous environmental agents through pollution, hazardous material/waste and waste pollutants. NIEHS also focuses on populations that are exposed to high concentrations of environmental agents that are thought to cause human disease.
NIEHS Overview (PDF)
NIOSH/CDC is responsible for conducting research and making recommendations for the prevention of work-related injuries and illness.
FDA is responsible for guaranteeing that all food being bought and sold in the U.S and in foreign commerce are safe and labeled properly, except those food products that are under USDA’s Food Safety and Inspection Services. FDA is also responsible foe ensuring that all animal drugs and feeds are safe, properly labeled and have no human health hazards when used in food-producing animals.
NTP relies on an Advisory Board and Committees for advice and input on projects.
The primary research methods used by NTP to test the toxicity of certain chemicals that are used in everyday items are chemical disposition and toxicokinetics. Chemical disposition studies the long and short term effects of chemicals through animal studies.
Chemical disposition determines the absorption of the chemical, how it spreads through out the animal’s tissue , its effects on the metabolism, and effects on the animal’s urine and feces. It also studies the course of exposure on all of these factors. In chemical disposition, animals are dosed with radio labeled chemicals, placed in metabolism cages for separate collection of urine, feces and expired air. When the animals die, tissues are removed from the animals. The amount of chemical activity is measured throughout this entire process, from the first injection of the chemical until the animal is dead.
Tokicokentics studies the change of the concentration of the chemical over time in the blood or other tissues. This information is important in relating chemical exposure to various biological processes, such as absorption or metabolism change. Tokicokinetic data on laboratory animals can be applied to humans through mathematical modeling. Tokicokentics studies are performed with unlabeled (no radio activity) chemicals. In these studies animals are dosed, blood samples are taken at predetermined times and analyzed. There are usually three blood samples per animal, the third sample being taken once the animal is dead. However, when more frequent sampling is required another process is used involving a jugular vein cannula, which is a thin plastic tube that is inserted into the body in order to drain out fluids. This allows researchers to takes multiple samples from the same animal.
Another form of testing is toxicology/carcinogenity. In toxicology assessments the studies performed are determined by the data that is needed for the specific chemicals being studied. Toxicology/carcinogenity studies generally fall into two categories; prechronic toxicity studies and two-year toxicology and carcinogens rodent studies.
Toxicology studies usually involve the exposure of rats and mice of both sexes to chemicals or occasionally to physical agents for about 14 to 90 days.
The choice of chemicals to be studied has always been an open nomination process. Nominations are requested by academia, Federal and State regulatory and health agencies, industry and unions, as well as from advocacy groups and the general public.
Substances are studied for a variety of health-related effects, including but not limited to, reproductive and developmental toxicity, genotoxicity, immunotoxicity, metabolism and disposition, and carcinogenicity. The possible public health consequences of exposure remain the over-riding factor in the decision to study a particular substance. Selections for government testing are based on the principle that some industries can be trusted to evaluate their own products for health and environmental effects. Nominations to the NTP should be based on one or more of the principles listed below.
Substances are chosen to be studied based on two broad categories:
· If they are thought to be hazardous to public health based on the amount of human exposure to the substance and/or suspicion of toxicity.
The NTP is an interagency program whose mission is to evaluate chemical, biological, and physical agents (collectively referred to as "substances") of public health concern by developing and applying tools of modern toxicology and molecular biology.
NTP has several contractors and partnerships that carry out multiple studies at several laboratories in the
Several environmental groups and independent researchers have challenged the use of the chemical plastiticizer Bisphenol-A. Bisphenol-A is the raw material for polycarbonate plastic. This chemical has been tied to cancer, reproductive abnormalities, diabetes and birth defects in laboratory animals. Especially when exposed to heat, this chemical can leach. In a report done in 2005 by the Centers for Disease Control and Prevention, 95% of the Americans tested had the chemical present in their body.
Audit of Controversial Chemical Report Shows No Impropriety (by Susanne Rust,
Update on BPA Report Controversy (by Liz Borkowski, Pump Handle)
News+Analysis Don't Ask, Don't Tell: NIH Didn’t Know about a Contractor’s Conflict of Interest Because It Never Bothered to Check (by Robert Brodsky, Government Executive)
WARNING: The chemical bisphenol A has been known to pose severe health risks to laboratory animals. AND THE CHEMICAL IS IN YOU. (by Susanne Rust, Meg Kissinger and
Chemicals In Our Food (by Bill Moyers, PBS Bill Moyers Journal)
There has been serious public controversy regarding the safety of aspartame, an artificial sweeter consumed by many Americans. According to the Star Tribune Online Nation/World, in 1996 the National Toxicology Program was pushed by government scientists to conduct animal studies in order to answer the questions about aspartame’s link to cancer. FDA officials urged NIEHS not to conduct the studies, arguing that they were satisfied with industry-sponsored research that had found no health risks linked to aspartame. NIEHS officials then chose not to carry out the research.
In 2008, researchers at Washington University of St. Louis issued a report pertaining to aspartame that renewed the fear of its connection to brain tumors. Some present and former NIEHS officials are criticizing the FDA for using their influence on NIEHS in a negative manner and delaying research that would have prevented the current controversy surrounding aspartame. The FDA still insists that aspartame is safe and that further research is not necessary. NIEHS managers have said that they are considering doing the research needed on aspartame.
The questioning of aspartame’s health risks started in the late 1970s and early 1980s when the FDA was trying to get aspartame approved as a food additive. At this time, the head of the FDA, Jere E. Goyan, refused to aprrove the use of aspartame as a result of study results documenting an increase of cancer in rats. Goyan was removed from his position as FDA Commisioner on the first day of Ronald Reagan's presidency in 1981, and replaced by Arthur Hull Hayes. That same year, Hayes approved aspartame as a food additive an FDA Public Board of Inquiry recommendation that opposed approval.
Aspartame Controversy (Wikipedia)
FDA Methods Questioned (by Greg Gordon, Dorway)
Aspartame Controversy (Optimal Wellness Center, Cancer Compass)
David A. Schwartz was director of NIEHS and NTP director from 2005 to 2007
Kenneth Olden was director of NIEHS and NTP from 1991 to 2005. Olden stepped down from his position in July 2003 after being director for 12 years.
David P. Rall was director of NIEHS from 1971 to 1990 and director of NTP from 1978 to 1990.
Paul Kotin was director of NIEHS from 1968 to 1971.