Scientists Spot Potent Tobacco Carcinogen

[tnmynatt]

http://www.forbes.com/forbeslife/health ... 35235.html

Scientists Spot Potent Tobacco Carcinogen

10.02.06, 12:00 AM ET

MONDAY, Oct. 2 (HealthDay News) -- U.S. researchers have pinpointed a key killer compound in cigarette smoke.

The chemical acrolein -- found in tobacco and also some cooking oils -- appears to be a prime cause of smoking-related lung cancer and some nonsmoking-related lung cancers as well, according to studies conducted with lung cancer cells.

Acrolein can trigger DNA mutations in cells while reducing the cell's ability to repair that damage, the researchers explained.

"Cigarettes have a lot of carcinogens, some are more potent and more abundant than others," said lead researcher Moon-shong Tang, from the departments of environmental medicine, pathology and medicine at New York University. "Acrolein is probably the true variant that causes smoking-induced lung cancer."

In fact, Tang's team found acrolein to be 10,000 times more prevalent than another class of carcinogen, called polycyclic aromatic hydrocarbons (PAHs), which had previously been identified as a cause of lung cancer.

The findings were expected to be published Monday in this week's issue of the Proceedings of the National Academy of Sciences.

Lung cancer remains the leading cause of cancer death for both men and women, killing more than 163,000 Americans each year, according to the American Cancer Society. Overall, lung cancer has only a 15 percent survival rate.

Tang noted that, in Asian countries, many women who don't smoke still get lung cancer. However, these women cook with oils that are heated to very high temperatures and release high amounts of acrolein. "We think this is related to female lung cancer," Tang said.

"Now we know the cause of smoking and nonsmoking lung cancer," Tang said.

The New York City researcher believes the finding has implications for preventing lung cancer and assessing the lung cancer risk of various populations.

If acrolein were removed from cigarettes, he speculated, they would be less likely to cause lung malignancies.

However, another expert believes that many other carcinogens in cigarette smoke contribute to cancer risk.

"It is not simple to conclude that any one carcinogen in cigarette smoke is necessarily responsible for lung cancer. It would be a mistake to do that," said Stephen S. Hecht, the Wallin Professor of Cancer Prevention at the Cancer Center and the Department of Laboratory Medicine and Pathology at the University of Minnesota and author of an accompanying commentary.

Hecht believes the notion of a "cancer-safe" cigarette is misguided.

"If people got the impression that by removing or reducing any one carcinogen from cigarette smoke that you could therefore produce a safe product with respect to lung cancer, that would be wrong," he said.

[RandyW]

ToxFAQs™

for

Acrolein

(Acroleína)

This fact sheet answers the most frequently asked health questions about acrolein. For more information, you may call the ATSDR Information Center at 1-888-422-8737. This fact sheet is one in a series of summaries about hazardous substances and their health effects. This information is important because this substance may harm you. The effects of exposure to any hazardous substance depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other chemicals are present.

HIGHLIGHTS: : Exposure to acrolein occurs mostly from breathing it in air. Cigarette smoke and automobile exhaust contain acrolein. Acrolein causes burning of the nose and throat and can damage the lungs. Acrolein has been found in at least 31 of the 1,662 National Priority List sites identified by the Environmental Protection Agency (EPA).

What is acrolein?

Acrolein is a colorless or yellow liquid with a disagreeable odor. It dissolves in water very easily and quickly changes to a vapor when heated. It also burns easily. Small amounts of acrolein can be formed and can enter the air when trees, tobacco, other plants, gasoline, and oil are burned.

Acrolein is used as a pesticide to control algae, weeds, bacteria, and mollusks. It is also used to make other chemicals.

What happens to acrolein when it enters the environment?

Acrolein may be found in soil, water, or air.

It breaks down fairly rapidly in the air (about half will disappear within 1 day) by reacting with other chemicals and sunlight.

Acrolein evaporates rapidly from soil and water.

How might I be exposed to acrolein?

Smoking tobacco or breathing air containing tobacco smoke or automobile exhaust.

Working in or living near industries where acrolein is manufactured or used to make other chemicals.

Inhaling vapors from overheated cooking oil or grease.

How can acrolein affect my health?

There is very little information about how exposure to acrolein affects people's health. The information we have indicates that breathing large amounts damages the lungs and could cause death. Breathing lower amounts may cause eye watering and burning of the nose and throat and a decreased breathing rate.

Animal studies show that breathing acrolein causes irritation to the nasal cavity, lowered breathing rate, and damage to the lining of the lungs.

We do not know if eating food or drinking water containing acrolein affects your health. However, animals that swallowed acrolein had stomach irritation, vomiting, stomach ulcers, and bleeding.

How likely is acrolein to cause cancer?

The Department of Health and Human Services (DHHS) has not classified acrolein as to its carcinogenicity. The International Agency for Research on Cancer (IARC) has determined that acrolein is not classifiable as to carcinogenicity in humans. The EPA has stated that the potential carcinogenicity of acrolein cannot be determined based on an inadequate database.

How can acrolein affect children?

In general, children are not likely to be affected by acrolein more than adults. However, children who are sensitive to irritants in the air (such as children with asthma) may be more sensitive to lung irritation from acrolein.

In animal studies, ingestion of very large amounts of acrolein during pregnancy caused reduced birth weights and skeletal deformities in newborns. However, the levels causing these effects were often fatal to the mother.

How can families reduce the risks of exposure to acrolein?

You can reduce your family's exposure to acrolein by reducing their exposure to tobacco smoke, smoke from burning wood products or cooking oils and grease, and exhaust from diesel or gasoline vehicles.

Is there a medical test to determine whether I've been exposed to acrolein?

Methods have been developed to detect acrolein or breakdown products of acrolein in biological or environmental samples; however, there are no specific medical tests available in a doctor's office to determine if you have been exposed to acrolein.

Has the federal government made recommendations to protect human health?

The Food and Drug Administration (FDA) has determined that the amount of acrolein used to prepare modified food starch must not be more than 0.6%.

The Occupational Safety and Health Administration (OSHA) has set limits of 0.1 parts of acrolein per million parts of workplace air (0.01 ppm) for 8 hour shifts and 40 hour work weeks.

The EPA has restricted the use of all pesticides containing acrolein.

References

Agency for Toxic Substances and Disease Registry (ATSDR). 1999. Managing Hazardous Materials Incidents. Volume III – Medical Management Guidelines for Acute Chemical Exposures: Acrolein. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.

Agency for Toxic Substances and Disease Registry (ATSDR). 2005. Toxicological Profile for acrolein. (Draft for Public Comment). Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.

Where can I get more information?

ATSDR can tell you where to find occupational and environmental health clinics. Their specialists can recognize, evaluate, and treat illnesses resulting from exposure to hazardous substances. You can also contact your community or state health or environmental quality department if you have any more questions or concerns.

For more information, contact:

Agency for Toxic Substances and Disease Registry

Division of Toxicology

1600 Clifton Road NE, Mailstop F-32

Atlanta, GA 30333

Phone: 1-888-42-ATSDR (1-888-422-8737)

FAX: (770)-488-4178

Email: ATSDRIC@cdc.gov