National Toxicology Program technical report series最新文献

The predominant source of human exposure to radio frequency radiation (RFR) occurs through usage of cellular phone handsets. The Food and Drug Administration nominated cell phone RFR emission for toxicology and carcinogenicity testing in 1999. At that time, animal experiments were deemed crucial because meaningful human exposure health data from epidemiological studies were not available. Male and female B6C3F1/N mice were exposed to time-averaged whole-body specific absorption rates of 0 (sham control), 5, 10, or 15 W/kg Global System for Mobile Communications (GSM)- or Code Division Multiple Access (CDMA)-modulated cell phone RFR at 1,900 MHz for 28 days or 0, 2.5, 5, or 10 W/kg GSM- or CDMA-modulated cell phone RFR for up to 2 years. Genetic toxicology studies were conducted in mouse peripheral blood erythrocytes and leukocytes, brain cells, and liver cells. (Abstract Abridged).

2,3-Butanedione is commonly used by the flavor manufacturing industry for production of artificial flavor formulations. Examples of flavored food products include popcorn, cake mixes, flour, beer, wine, margarines and soft spreads, cheese, candy, bakery products, crackers, cookies, ice cream, frozen foods, and many other food and beverage products. 2,3-Butanedione was nominated by the United Food and Commercial Workers Union for long-term inhalation studies due to outbreaks of bronchiolitis obliterans in workers exposed to its vapors. Male and female Wistar Han [Crl:WI(Han)] rats and B6C3F1/N mice were exposed to 2,3-butanedione (greater than or equal to 98.5%) by inhalation for 3 months or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Escherichia coli, mouse bone marrow cells, and rat and mouse peripheral blood erythrocytes. (Abstract Abridged).

p-Chloro-α,α,α-trifluorotoluene is a solvent used in paints and coatings and as an industrial intermediate in the production of other chemicals (e.g., herbicides, dyes, pharmaceuticals). p-Chloro-α,α,α-trifluorotoluene was nominated for study by the National Cancer Institute and Kowa American Corporation for study because of its high import volume and lack of occupational exposure limits. Male and female Hsd:Sprague Dawley SD rats and B6C3F1/N mice were exposed to p-chloro-α,α,α-trifluorotoluene (purity greater than 99.5%) by inhalation for 3 months or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, Escherichia coli, and rat and mouse peripheral blood erythrocytes. (Abstract Abridged).

Antimony trioxide (Sb2O3) is used as a flame retardant in canvas, textiles, paper, and plastics and in combination with some chlorinated or brominated flame retardants on commercial furniture, draperies, wall coverings, and carpets. It is also used in batteries, enamels and paint pigment, and ceramics and fiberglass. Occupationally, the major sources of exposure to antimony exist in the metal ore smelting and mining industries. Antimony trioxide was nominated by the Consumer Product Safety Commission and the National Institute of Environmental Health Sciences for National Toxicology Program testing due to the potential for substantial human exposure in occupational settings and the lack of adequate 2-year exposure carcinogenicity studies. Male and female Wistar Han [Crl:WI (Han)] rats and B6C3F1/N mice were exposed to antimony trioxide (greater than 99.9% pure) by inhalation for 2 weeks or 2 years. Genetic toxicology studies were conducted in rat and mouse peripheral blood erythrocytes, peripheral blood leukocytes, and lung cells. (Abstract Abridged).

Indole-3-carbinol is sold as a sole ingredient in dietary supplements or as a combination nutraceutical along with a variety of herbs and/or vitamins. It is marketed for its potential ability to prevent cancer and provide other health benefits, such as detoxifying the liver and boosting the immune system. Indole-3-carbinol is a naturally formed breakdown product of glucosinolate glucobrassicin, a component found in cruciferous vegetables of the Brassica genus, including broccoli, brussels sprouts, cauliflower, cabbage, kale, kohlrabi, and turnips. Exposure to indole-3-carbinol occurs through the oral route through the ingestion of Brassica vegetables or dietary supplements. Indole-3-carbinol was nominated by the National Cancer Institute for toxicity and carcinogenicity testing because of its occurrence in natural products and for its potential use as a breast cancer chemopreventive agent. Male and female F344/N rats and Harlan Sprague Dawley rats received indole-3-carbinol in corn oil by gavage for 3 months or 2 years, respectively. Male and female B6C3F1/N mice received indole-3-carbinol in corn oil gavage for 3 months or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Escherichia coli, rat bone marrow cells, and mouse peripheral blood erythrocytes. (Abstract Abridged).

TRIM VX is a metalworking fluid used as a lubricant and coolant liquid and for cleaning tools and parts during cutting, drilling, milling, and grinding. The metalworking fluid class was nominated by the National Institute for Occupational Safety and Health (NIOSH) for study by the National Toxicology Program because of high production volumes, the large number of occupationally exposed workers, the lack of carcinogenicity and chronic toxicology data, and because epidemiologic data indicate an increased incidence of laryngeal cancer in workers exposed to metalworking fluids. TRIM VX was selected as an example soluble oil metalworking fluid following chemical analysis and collaboration with NIOSH. Male and female Wistar Han [Crl:WI (Han)] rats and B6C3F1/N mice were exposed to TRIM VX by inhalation for 3 months or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, Escherichia coli, and rat and mouse peripheral blood erythrocytes. (Abstract Abridged).

Dried concentrated extracts from Camellia sinensis contain high amounts of catechins and are a popular source for green tea extract nutraceutical supplements and medicinal uses. Supplements containing green tea extract are commonly consumed for weight loss and green tea extracts are popular ingredients in sunblocks, cream rinses, and other cosmetics. Numerous studies in both experimental animals and clinical settings have examined the possible anticancer, anti-inflammatory, antimicrobial, and cardio- and neuroprotective properties of green tea extract. The presumed active ingredient of green tea extract, epigallocatechin gallate (EGCG), was originally nominated by the National Cancer Institute for toxicity and carcinogenicity studies because it is the most abundant catechin in green tea extract, it was being investigated as a potential chemotherapeutic agent, and there was a lack of adequate information with regard to its toxicity. However, the NTP selected green tea extract [containing EGCG (48.4% by weight) and other green tea catechins] for study because human exposure is to green tea extract products that contain concentrated mixtures of various green tea catechins. The NTP analyzed four lots of green tea extract and selected a source based on quantities of EGCG, consistency with other products on the market, and availability in bulk quantity. Oral gavage was chosen as the route of administration because it was considered most relevant to human exposure. Male and female F344/NTac rats and B6C3F1/N mice were administered green tea extract in water by gavage for 3 months and male and female Wistar Han [Crl:WI(Han)] rats (referred to as Wistar Han rats) and B6C3F1/N mice were administered green tea extract in water by gavage for 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, Escherichia coli, and mouse peripheral blood erythrocytes. (Abstract Abridged).

DE-71, a pentabromodiphenyl ether mixture, was used in the past as an additive flame retardant, often in furniture materials. Additive flame retardants are mixed into products, but they are not covalently bound to the polymers in the commercial products, and thus can leach out into the environment. Though use and sale of polybrominated diphenyl ethers (PBDEs) was banned in the European Union and production was voluntarily phased out in the United States around 2004, they remain in the environment as products produced before use was discontinued or as discarded products. PBDEs can be found in water, wildlife, and in humans, as well as in various food products including meat, poultry, and fish. The California Office of Environmental Health Hazard Assessment nominated individual PBDE congeners for study because they were considered a health risk and have been found in human and animal tissue in the United States. Because of limited availability of the individual PBDE congeners, DE-71, the flame retardant used in furniture, was evaluated in rats and mice to characterize the toxic and carcinogenic potential of PBDEs. Male and female F344/N rats and B6C3F1/N mice were administered DE-71 in corn oil by gavage for 3 months. Wistar Han [Crl:WI(Han)] dams (referred to as Wistar Han rats) were administered DE-71 in corn oil by gavage from gestational day (GD) 6 through postnatal day (PND) 20. Their pups were administered the same doses in corn oil by gavage from PND 12 through 2 years. Male and female B6C3F1/N mice were administered DE-71 in corn oil by gavage for 2 years. Genetic toxicology studies of DE-71 as well as three individual PBDEs were conducted in Salmonella typhimurium and Escherichia coli, mouse bone marrow cells, and mouse peripheral blood erythrocytes. (Abstract Abridged).

Bromodichloroacetic acid is a haloacetic acid that forms when drinking water supplies containing natural organic matter are disinfected with chlorine-containing oxidizing compounds and when bromide is present in the source water. Bromodichloroacetic acid was nominated for toxicity and carcinogenicity studies by the American Water Works Association Research Foundation and the United States Environmental Protection Agency because of widespread human exposure to this water disinfection by-product and because related dihaloacetic acids were found to be carcinogenic to the liver of rats and mice. Male and female F344/N rats and B6C3F1/N mice were exposed to bromodichloroacetic acid (greater than 97% pure) in drinking water for 2 weeks or 3 months, and male and female F344/NTac rats and B6C3F1/N mice were exposed for 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, Escherichia coli, and mouse peripheral blood erythrocytes. (Abstract Abridged).

CIMSTAR 3800 is a metalworking fluid used as a lubricant and coolant liquid on the surface of the worked piece to remove heat and fine swarf and to provide corrosion inhibition at the newly cut surface. CIMSTAR 3800 is used in the general machining and grinding of automotive aluminum parts and on light to moderate machining and grinding of light steel, stainless steels, hardened steels, and other materials. CIMSTAR 3800 was nominated by the National Institute for Occupational Safety and Health for study by the National Toxicology Program because of its high production volume, the large number of occupationally exposed workers, the lack of carcinogenicity and chronic toxicology data, and because epidemiologic data indicate an increased incidence of laryngeal cancer in workers exposed to metalworking fluids. Male and female F344/NTac rats and B6C3F1/N mice were exposed to CIMSTAR 3800 by inhalation for 3 months, and male and female Wistar Han [Crl:WI (Han)] rats (referred to as Wistar Han rats) and B6C3F1/N mice were exposed to CIMSTAR 3800 by inhalation for 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, Escherichia coli, and rat and mouse peripheral blood erythrocytes. (Abstract Abridged).