HHS/NIH Expands List of Carcinogens

By Mary Jane Dittmar 

To be harmful to your present or potential health, environments do not necessarily have to be immediately dangerous to life and health.

The U.S. Department of Health and Human Services (HHS) recently added eight substances to its report on carcinogens. This science-based document identifies chemicals and biological agents that may increase the risk of cancer for humans. 

The following were added to the 12th Report on Carcinogens, which includes 240 listings. The industrial chemical formaldehyde and the botanical aristolochic acid are listed as known human carcinogens. Captafol, cobalt-tungsten carbide (in powder or hard metal form), certain inhalable glass wool fibers, o-nitrotoluene, riddelliine, and styrene were added as substances that are reasonably anticipated to be human carcinogens. The entire report is at http://ntp.niehs.nih.gov/go/roc12.

John Bucher, Ph.D., associate director of the National Toxicology Program (NTP), which compiles the report, explains: “This report underscores the critical connection between our nation’s health and what’s in our environment.”

The Report on Carcinogens is a congressionally mandated document that identifies agents, substances, mixtures, or exposures known to be human carcinogens and those reasonably anticipated to be human carcinogens. A listing as a known or an anticipated carcinogen does not by itself mean that a substance will cause cancer. Factors such as the amount and duration of exposure and an individual’s susceptibility to a substance will affect whether a person will develop cancer.

Substances nominated by the public or private sector and selected for consideration undergo an extensive evaluation during which the scientific community and public are given opportunities to provide input. At least six opportunities for public input were made available on each of the above listed substances. The NTP used established criteria to evaluate the scientific evidence on each substance under review, based on the scientific expertise of federal agencies, including the National Institutes of Health, Centers for Disease Control and Prevention, Agency for Toxic Substances and Disease Registry, U.S. Food and Drug Administration, U.S. Environmental Protection Agency, U.S. Consumer Product Safety Commission, and the Occupational Safety and Health Administration.

The Report on Carcinogens contains a detailed description of each substance:
Known Human Carcinogens

Formaldehyde. Originally, it was first listed in the 2nd Report on Carcinogens as a substance reasonably anticipated to be a human carcinogen. Subsequent laboratory studies showed it caused nasal cancer in rats. There is now sufficient evidence from studies in humans to show that individuals with higher measures of exposure to formaldehyde are at increased risk for certain types of rare cancers, including nasopharyngeal (the nasopharnyx is the upper part of the throat behind the nose), sinonasal, as well as a specific cancer of the white blood cells known as myeloid leukemia. Formaldehyde is a colorless, flammable, strong-smelling chemical widely used to make resins for household items such as composite wood products, paper product coatings, plastics, synthetic fibers, and textile finishes. Formaldehyde is also commonly used as a preservative in medical laboratories; mortuaries; and some consumer products, including some hair straightening products.

Aristolochic acids have been shown to cause high rates of bladder or upper urinary tract cancer among individuals with kidney or renal disease who consumed botanical products containing aristolochic acids. Despite a warning issued in 2001 by the U.S. Food and Drug Administration that advised consumers to discontinue use of any botanical products containing aristolochic acids, these products can still be purchased on the Internet and abroad, and may be found as a contaminant in herbal products used to treat diseases such as arthritis, gout, and inflammation.

Reasonably Anticipated To Be Human Carcinogens

Captafol, a fungicide used to control fungal diseases in fruits, vegetables, ornamental plants, and grasses, and as a seed treatment, induced cancer in experimental animal studies, which demonstrated that dietary exposure to captafol caused tumors at several different tissue sites in rats and mice. It has been banned in the United States since 1999, but past exposures may still affect health.

Cobalt-tungsten carbide (in powder and hard metal form) showed limited evidence of lung cancer in workers involved in cobalt-tungsten carbide hard- metal manufacturing. It is used to make cutting and grinding tools, dies, and wear-resistant products for a broad spectrum of industries, including oil and gas drilling, as well as mining. In the United States, cobalt-tungsten hard metals are commonly referred to as cemented or sintered carbides.

Certain inhalable glass wool fibers made the list based on experimental animal studies. Not all glass wool or man-made fibers were found to be carcinogenic. The specific glass wool fibers referred to in this report have been redefined from previous reports on carcinogens to include only those fibers that can enter the respiratory tract, are highly durable, and are biopersistent, meaning they remain in the lungs for long periods of time. Glass wool fibers generally fall into two consumer categories: low-cost, general purpose fibers and premium, special purpose fibers. General purpose glass wool fibers are predominantly used for home and building insulation, which appears to be less durable and less biopersistent than the premium fibers, and are thus believed to be less likely to cause cancer in humans.

o-Nitrotoluene is listed because experimental animal studies showed tumor formation at many different tissue sites in rats and mice. It is used as an intermediate in the preparation of azo dyes and other dyes, including magenta and various sulfur dyes for cotton, wool, silk, leather, and paper. It is also used in preparing agricultural chemicals, rubber chemicals, pesticides, petrochemicals, pharmaceuticals, and explosives. Workers in the United States are likely exposed to o-nitrotoluene through the skin or from breathing it during production, and use. o-Nitrotoluene has also been detected in air and water near facilities that produce munitions, and near military training facilities.

Riddelliine has been found to cause cancer of the blood vessels in rats and mice, leukemia and liver cancer in rats, and lung tumors in mice. (This botanical has no connection to the drug Ritalin, prescribed for the treatment of attention-deficit hyperactivity disorder.) Riddelliine is found in certain plants of the genus Senecio, a member of the daisy family grown in sandy areas in the western United States and other parts of the world. Some common names for Senecio plants are ragwort and groundsel. Riddelliine-containing plants are not used for food in the United States and have no known commercial uses.

However, at least 13 Senecio species have been identified that are used in herbal medicines or possibly as food in other parts of the world. Human exposure can result from eating or drinking herbal medicine or teas, honey, or foods contaminated by parts of Senecio plants, or after consuming products from animals that have fed on the plants.

The greatest exposure to styrene in the general population is through cigarette smoking. Photo courtesy of www.photo8.com.

Styrene is on the list based on human cancer studies, laboratory animal studies, and mechanistic scientific information. The limited evidence of cancer from studies in humans shows lymphohematopoietic cancer and genetic damage in the white blood cells, or lymphocytes, of workers exposed to styrene.

Styrene is a synthetic chemical used worldwide in the manufacture of products such as rubber, plastic, insulation, fiberglass, pipes, automobile parts, food containers, and carpet backing. People may be exposed to styrene by breathing indoor air that has styrene vapors from building materials, tobacco smoke, and other products. The greatest exposure to styrene in the general population is through cigarette smoking. Workers in certain occupations may potentially be exposed to much higher levels of styrene than the general population.

For more information about the NTP, visit http://ntp.niehs.nih.gov.

Source: The U.S. Department of Health and Human Services (HHS) National Institutes of Health (NIH) News National Institute of Environmental Health Sciences (NIEHS) <http://www.niehs.nih.gov/> Contact: Robin Mackar, NIEHS, (919) 541-0073, <e-mail:rmackar@niehs.nih.gov>

When preplanning the structures in your first-due jurisdiction, you can better protect your health if you know what types of products are manufactured in the industrial buildings and what types of insulation and other construction materials are contained in business and residential structures alike. It would also be helpful if you could get this information for jurisdictions to which you regularly respond as mutual aid. Then, be sure to adapt (or institute) policies that will help to protect you while mitigating emergencies in these areas. Of course, the policies will help only if they are enforced. Remember, your self-contained breathing apparatus and personal protective equipment that covers your skin are especially essential in these atmospheres, even if they are not immediately dangerous to life and health.


Tony A. Garcia, chief fire officer, Battalion 12, C-Shift, and Bill Gustin, captain, both of the Miami-Dade (FL) Fire Rescue Department have called my attention to the following message “Dear 16-Year-Old Me,” available at the Firefighter Cancer Support Network. It raises young people’s awareness of their high risk for melanoma, a skin cancer that can be deadly if not caught in time. Young people have  a sense of immortality, and the last thing on their mind while enjoying the beach and getting the tan they covet so much is the possibility that they are putting themselves at risk for a deadly disease.




Just click on the link (Click here for more info…) and view the message. Then, help educate your children and grandchildren, your community’s high-school students, any young people with whom you are in contact, and any adults who have access to this age group. Make them aware of the risks and of ways to protect themselves when in the sun. Why not send the linked message to them?

Mary Jane Dittmar is senior associate editor of Fire Engineering and conference manager of FDIC. Before joining the magazine in January 1991, she served as editor of a trade magazine in the health/nutrition market and held various positions in the educational and medical advertising fields. She has a bachelor’s degree in English/journalism and a master’s degree in communication arts.


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