National Toxicology Program

National Toxicology Program
http://ntp.niehs.nih.gov/go/current

Areas of Research


NTP has a broad mandate to provide toxicological characterizations for chemicals and agents of public health concern and strives to balance the selection of chemicals for study. This has resulted in a diverse research program, but with emphasis on synthetic industrial chemicals, pesticides, various pharmaceuticals, metals, and food additives. NTP continues to explore new areas of research. In general, these initiatives are broad-based and include various health-related endpoints.

Endocrine Disruptors

Endocrine disruptors are naturally occurring or man-made substances that may mimic or interfere with natural hormones in the body. Endocrine disruptors may turn on, shut off, or modify signals that hormones carry, therefore affecting the normal functions of tissues and organs. NTP is involved in several efforts to strengthen the science base within this field.

For contact information, visit the Toxicology Branch.

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Occupational Mixtures and Exposures

NTP is coordinating an effort between NIEHS/NIH and NIOSH/CDC to better characterize worker exposures, educate workers, and identify occupational health research gaps. Current efforts are addressing worker exposure to asphalt fumes and 1-bromopropane and future initiatives are proposed for occupational mixtures such as welding fumes, abrasive blasting compounds, and metal working fluids. An industry consortium has petitioned the EPA to list 1-bromopropane as an alternative for ozone-depleting solvents for general metals, precision and electronics cleaning, aerosols, and adhesives. If this occurs, there is potential for a vast increase in the exposure of workers and the public to this compound. Currently, an appropriate occupational exposure limit for 1-bromopropane is not available. Asphalt fumes generated during road paving have been linked to acute irritation of mucous membranes and skin, but to date no cancer risk has been established. A study is underway to characterize asphalt fume composition including polycyclic aromatic hydrocarbons, develop a bioanalytical method that can be used to characterize exposure in laboratory inhalation studies, and assay gene expression response to asphalt fume exposure.

For contact information, visit the Toxicology Branch.

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Phototoxicology

As a result of the public's increasing exposure to ultraviolet radiation from sunlight and other sources such as tanning booths, NTP has initiated research to learn what toxic effects, if any, might occur from such exposures. NTP is coordinating an effort between NIEHS/NIH and NCTR/FDA to study the phototoxicology and photocarcinogenicity of substances nominated to NTP including those of high priority to the FDA. In general, these studies investigate the effects on gene expression, toxicity, and carcinogenicity of sunlight combined with either topically or systemically applied substances in the SKH-1 hairless mouse. Much of this research is being carried out at the NTP Center for Phototoxicology.

For more information, contact Dr. Nigel Walker.

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Safe Drinking Water

More than 200 million Americans use municipally treated drinking water, so the availability of safe drinking water is of enormous health significance. Although chlorination is considered one of the major public health advances of the 20th century, chemical disinfection by-products of chlorination or other disinfection processes may cause health problems such as cancer. In addition, there are agents found naturally in water or are present by contamination of public water systems that may pose a threat to public health. The U.S. Environmental Protection Agency has responsibility to set water standards for DBPs. To provide scientific data for setting sound water quality standards, NTP is collaborating with the EPA on a research program which includes a systematic, mechanism-based, toxicological evaluation of DBPs focusing on reproductive toxicity, immunotoxicity, neurotoxicity, and carcinogenicity. Selection of DBPs is based on their presence in drinking water, occurrence with different disinfection processes, chemical structures, and representation of several DPB classes: trihalomethanes, haloacetic acids, and haloacetonitriles.

NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.