Navigation Links
Big Tobacco knew radioactive particles in cigarettes posed cancer risk but kept quiet

Tobacco companies knew that cigarette smoke contained radioactive alpha particles for more than four decades and developed "deep and intimate" knowledge of these particles' cancer-causing potential, but they deliberately kept their findings from the public, according to a new study by UCLA researchers.

The analysis of dozens of previously unexamined internal tobacco industry documents, made available in 1998 as the result of a legal settlement, reveals that the industry was aware of cigarette radioactivity some five years earlier than previously thought and that tobacco companies, concerned about the potential lung cancer risk, began in-depth investigations into the possible effects of radioactivity on smokers as early as the 1960s.

"The documents show that the industry was well aware of the presence of a radioactive substance in tobacco as early as 1959," the authors write. "Furthermore, the industry was not only cognizant of the potential 'cancerous growth' in the lungs of regular smokers, but also did quantitative radiobiological calculations to estimate the long-term lung radiation absorption dose of ionizing alpha particles emitted from cigarette smoke." The study, published online Sept. 27 in Nicotine & Tobacco Research, the peer-reviewed journal of the Society for Research on Nicotine and Tobacco, adds to a growing body of research detailing the industry's knowledge of cigarette smoke radioactivity and its efforts to suppress that information.

"They knew that the cigarette smoke was radioactive way back then and that it could potentially result in cancer, and they deliberately kept that information under wraps," said the study's first author, Hrayr S. Karagueuzian, a professor of cardiology who conducts research at UCLA's Cardiovascular Research Laboratory, part of the David Geffen School of Medicine at UCLA. "Specifically, we show here that the industry used misleading statements to obfuscate the hazard of ionizing alpha particles to the lungs of smokers and, more importantly, banned any and all publication on tobacco smoke radioactivity."

The radioactive substance - which the UCLA study shows was first brought to the attention of the tobacco industry in 1959 - was identified in 1964 as the isotope polonium-210, which emits carcinogenic alpha radiation. Polonium-210 can be found in all commercially available domestic and foreign cigarette brands, Karagueuzian said, and is absorbed by tobacco leaves through naturally occurring radon gas in the atmosphere and through high-phosphate chemical fertilizers used by tobacco growers. The substance is eventually inhaled by smokers into the lungs.

The study outlines the industry's growing concerns about the cancer risk posed by polonium-210 inhalation and the research that industry scientists conducted over the decades to assess the radioactive isotope's potential effect on smokers - including one study that quantitatively measured the potential lung burden from radiation exposure in a two-pack-a-day smoker over a two-decade period.

Karagueuzian and his colleagues made independent calculations using industry and academic data and arrived at results that very closely mirrored those of that industry study, which was conducted nearly a quarter-century ago. They then compared those results to rates used by the Environmental Protection Agency to estimate lung cancer risk among individuals exposed to similar amounts of alpha particle-emitting radon gas in their homes.

"The gathered data from the documents on the relevant radiobiological parameters of the alpha particles - such as dose, distribution and retention time - permitted us to duplicate the industry's secretly estimated radiation absorbed dose by regular smokers over a 20- or 25-year period, which equaled 40 to 50 rads," he said. "These levels of rads, according to the EPA's estimate of lung cancer risk in residents exposed to radon gas, equal 120 to 138 deaths per 1,000 regular smokers over a 25-year period."

Despite the potential risk of lung cancer, tobacco companies declined to adopt a technique discovered in 1959 and then another developed in 1980 that could have helped eliminate polonium-210 from tobacco, the researchers said. The 1980 technique, known as an acid-wash, was found to be highly effective in removing the radioisotope from tobacco plants, where it forms a water-insoluble complex with the sticky, hair-like structures called trichomes that cover the leaves.

And while the industry frequently cited concerns over the cost and the possible environmental impact as rationales for not using the acid wash, UCLA researchers uncovered documents that they say indicate the real reason may have been far different.

"The industry was concerned that the acid media would ionize the nicotine, making it more difficult to be absorbed into the brains of smokers and depriving them of that instant nicotine rush that fuels their addiction," Karagueuzian said. "The industry also were well aware that the curing of the tobacco leaves for more than a one-year period also would not eliminate the polonium-210, which has a half-life of 135 days, from the tobacco leaves because it was derived from its parent, lead-210, which has a half-life of 22 years."

Karagueuzian said the insoluble alpha particles bind with resins in the cigarette smoke and get stuck and accumulate at the bronchial bifurcations of the lungs, forming "hot spots," instead of dispersing throughout the lungs. In fact, previous research on lung autopsies in smokers who died of lung cancer showed that malignant growths were primarily located at the same bronchial bifurcations where these hot spots reside.

"We used to think that only the chemicals in the cigarettes were causing lung cancer," Karagueuzian said. "But the case of the these hot spots, acknowledged by the industry and academia alike, makes a strong case for an increased probability of long-term development of malignancies caused by the alpha particles. If we're lucky, the alpha particle-irradiated cell dies. If it doesn't, it could mutate and become cancerous."

Karagueuzian said the findings are very timely in light of the June 2009 passage of the Family Smoking Prevention and Tobacco Control Act, which grants the U.S. Food and Drug Administration broad authority to regulate and remove harmful substances - with the exception of nicotine - from tobacco products. The UCLA research, he said, makes a strong case that the FDA ought to consider making the removal of alpha particles from tobacco products a top priority.

"Such a move could have a considerable public health impact, due to the public's graphic perception of radiation hazards," he said.

To uncover the information, Karagueuzian and his team combed through the internal tobacco industry documents made available online as part of the landmark 1998 Tobacco Master Settlement Agreement. Documents from Philip Morris, R.J. Reynolds, Lorillard, Brown I Williamson, the American Tobacco Company, the Tobacco Institutes and the Council for Tobacco Research, as well as the Bliley documents, were examined, Karagueuzian said.

The team searched for key terms such as "polonium-210," "atmospheric fallout," "bronchial epithelium," "hot particle" and "lung cancer," among others.

Karagueuzian said the earliest causal link between alpha particles and cancer was made in around 1920, when alpha particle-emitting radium paint was used to paint luminescent numbers on watch dials. The painting was done by hand, and the workers commonly used their lips to produce a point on the tip of the paint brush. Many workers accumulated significant burdens of alpha particles through ingestion and absorption of radium-226 into the bones and subsequently developed jaw and mouth cancers. The practice was eventually discontinued.

Another example involves liver cancer in patients exposed to chronic low-dose internal alpha particles emitted from the poorly soluble deposits of thorium dioxide after receiving the contrast agent Thorotrast. It has been suggested that the liver cancers resulted from point mutations of the tumor suppressor gene p53 by the accumulated alpha particles present in the contrast media. The use of Thorotrast as contrast agent was stopped in the 1950s.


Contact: Kim Irwin
University of California - Los Angeles Health Sciences

Related medicine news :

1. ClearWay Minnesota(SM) Shines a Spotlight on a Reinvented Tobacco Industry
2. Health Groups Ask Supreme Court to Authorize Financial Penalties on Tobacco Companies for Decades of Wrongdoing
3. New Study Finds Similar Advertising Strategies Used by Indoor Tanning and Tobacco Industries
4. Fifth Anniversary of Global Tobacco Control Treaty Presents Opportunity For U.S. Ratification and Leadership
5. FDA Appoints Highly Qualified Scientific Experts to Tobacco Products Scientific Advisory Committee
6. The Electronic Cigarette Company Challenges the Rt Hon Andy Burnham MP to Ban All Tobacco Products on 21st June 2010
7. Legacy(SM) Case for Tobacco Funds to be Heard by Ohio Supreme Court
8. Electronic Cigarettes Are Tobacco Products, States AAPHP
9. Long Island Press Investigates Big Tobacco's Lobby to Kill Indian Cigarette Trade
10. Congress Approves Bill Curbing Internet Tobacco Sales in Victory for Kids and Taxpayers
11. New technique reduces tobacco smoke damage to lungs in mice
Post Your Comments:
(Date:11/25/2015)... ... November 25, 2015 , ... Lakeview Health, ... country to celebrate their sobriety and show through pictures what a positive difference ... photos this Thanksgiving with the hashtag #FacesOfGratitude on their Facebook, Twitter, and Instagram ...
(Date:11/25/2015)... ... November 25, 2015 , ... On November 23rd 2015 Cozy Products, ... heating products business. Cozy Products explains what this means for business moving forward. , ... the Cozy Products business model: to sell personal heaters that reduce energy consumption, are ...
(Date:11/25/2015)... Livonia, MI (PRWEB) , ... November 25, 2015 , ... ... at Presence Resurrection Medical Center (RMC) in Chicago, IL, UV Angel is evaluating the ... the medical and surgical intensive care units (totaling 30 beds) from May 2014 through ...
(Date:11/25/2015)... ... November 25, 2015 , ... ... found that regular bras were incredibly uncomfortable," said an inventor from Bronx, N.Y. ... , She developed the patent-pending RECOVERY BRA for added comfort and support. The ...
(Date:11/25/2015)... ... , ... Since its launch in 2012, the Regenestem brand ... therapies to patients with chronic degenerative medical conditions. Now, the U.S. Patent and ... , Organizations are required to hold a registered trademark in order to make ...
Breaking Medicine News(10 mins):
(Date:11/24/2015)... 24, 2015  Thanks to a donor with a ... Medical Center,s Sister Diane Grassilli Center for Women,s Health ... San Francisco . ... forward with a gift of $617,320 that allowed the ... with Tomosynthesis and Whole Breast Ultrasound. Tomosynthesis, three-dimensional (3-D) ...
(Date:11/24/2015)... , Nov. 24, 2015  Array BioPharma Inc. ... Chief Executive Officer, Ron Squarer , will ... in New York.  The public is welcome to ... the Array BioPharma website.Event:Piper Jaffray Annual Healthcare ConferencePresenter:  ... December 2, 2015Time:1:30 p.m. Eastern Time Webcast: ...
(Date:11/24/2015)... Nov. 24, 2015 /PRNewswire/ - ESSA Pharma Inc. ("ESSA" ... announced today that the first patient has been enrolled ... a treatment for metastatic castration-resistant prostate cancer ("mCRPC"). ... --> the United States ... Phase 1/2 clinical trial, ESSA intends to demonstrate the ...
Breaking Medicine Technology: