Studies show exposure to diesel exhaust may increase lung cancer mortality
Heavy diesel exhaust (DE) exposure in humans may increase the risk of dying from lung cancer, according to two papers released March 2nd by the Journal of the National Cancer Institute.
Starting in the 1980s, studies have investigated a possible causal relationship between exposure to diesel exhaust and lung cancer. In 1989, the International Agency for Research on Cancer (IARC) classified diesel exhaust as a probable carcinogen.
To determine the association between diesel exhaust exposure and the risk of dying from lung cancer, Michael D. Attfield, Ph.D., formerly of the National Institute for Occupational Safety and Health, in Morgantown, West Virginia, Debra T. Silverman, Sc.D., of the National Cancer Institute, and colleagues, conducted a cohort study of 12 315 workers in eight underground nonmetal mining facilities, called the Diesel Exhaust in Miners Study. Information was collected on workers starting in the year of introduction of diesel-powered equipment in each facility (between 1947 and 1967) to the end of the follow-up period on Dec. 31, 1997. The authors estimated the exposure of each worker to respirable elemental carbon (REC), a surrogate for diesel exhaust exposure, from a variety of sources including a 1998-2001 survey of diesel exhaust exposure at each facility, data from the US Mine Safety and Health Administration Mine Information Data Analysis System compliance database, data on diesel equipment usage over time at each facility, and historical mine ventilation data.
The researchers found a statistically significantly increased risk of lung cancer with increasing REC exposure among underground workers. Some evidence of increased risk was also shown for longer-term workers above ground who were exposed to elevated levels of REC. Other workplace exposures such as silica, asbestos, non-diesel exhaust-related polycyclic aromatic hydrocarbons, respirable dust, and radon, had little or no effect on the findings.
Silverman, lead author of the study, and her colleagues conducted another study, a nested case-control study of lung cancer deaths in 198 workers, drawn from the same cohort of workers in the original study. In the nested case-control study, the researchers also found a statistically significantly increased risk of lung cancer mortality with increasing levels of exposure to REC, after adjusting for smoking history, employment in high-risk occupations for lung cancer, and history of nonmalignant respiratory diseases.
Silverman writes, "Our findings are important not only for miners but also for the 1.4 million American workers and the 3 million European workers exposed to diesel exhaust and for urban populations worldwide," adding that in past decades, cities such as Mexico City, Estarreja, Portugal, and nine urban centers in China have reported diesel exposure levels comparable to some underground workers in the lower range of diesel exposure found in this study.
"Because such workers had at least a 50% increased lung cancer risk, our results suggest that the high air concentrations of elemental carbon reported in some urban areas may confer increased risk of lung cancer," Silverman continues. "Thus, if the diesel exhaust/lung cancer relation is causal, the public health burden of the carcinogenicity of inhaled diesel exhaust in workers and in populations of urban areas with high levels of diesel exposure may be substantial."
Silverman and colleagues point out certain limitations of their study, namely the uncertainty in retrospective exposure assessment and information on workers' hazardous exposures before and after the study job, and the fact that certain lifestyle factors, such as smoking, were obtained from next of kin.
In an accompanying editorial, Lesley Rushton, Ph.D., of Imperial College in London, writes that this sharp rise in risk at lower levels of diesel exposure necessitates "stringent occupational and particularly environmental standards for DE exposure." Her suggestions include: improving ventilation and regular vehicle maintenance, limiting workers' time in vehicles, and turning off engines when vehicles are not in use. Furthermore, reducing carbon exposure in the general environment poses an imminent challenge. "The necessity for such reduction is becoming increasingly apparent and is essential if the health of large numbers of people is not to be compromised," Rushton writes.
Provided by Journal of the National Cancer Institute
- Diesel exhaust exposure biomarker found Jul 31, 2007 | not rated yet | 0
- Diesel exhaust inhalation stresses your brain Mar 11, 2008 | not rated yet | 0
- Diesel-engine exhaust filter reduces harmful particles by 98 percent Apr 11, 2011 | not rated yet | 0
- Diesel exhaust associated with higher heart attack, stroke risk in men Nov 06, 2007 | not rated yet | 0
- Diesel exhaust fumes affect people with asthma, study finds Dec 06, 2007 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Why is zone 1 in liver more prone to ischemic injury?
23 hours ago Hi, Is it because around central vein, there is only deoxygenated blood from the vein where as in the periphery there is hepatic artery. Also why...
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013 As title suggest. Thanks :smile:
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013 Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
- More from Physics Forums - Medical Sciences
More news stories
Breast cancer characterized as "triple negative" carries a poor prognosis, with limited treatment options. In some cases, chemotherapy doesn't kill the cancer cells the way it's supposed to. New research from Western University ...
Cancer 9 hours ago | 5 / 5 (2) | 0
Mayo Clinic researchers have used next generation genomic analysis to determine that some of the more aggressive prostate cancer tumors have similar genetic origins, which may help in predicting cancer progression. The findings ...
Cancer 9 hours ago | not rated yet | 0
Even while being dragged to its destruction inside a cell, a cancer-promoting growth factor receptor fires away, sending signals that thwart the development of tumor-suppressing microRNAs (miRNAs) before it's dissolved, researchers ...
Cancer 10 hours ago | not rated yet | 0 |
Treating pediatric leukemia patients with a liposomal formulation of anthracycline-based chemotherapy at a more intense-than-standard dose during initial treatment may result in high survival rates without causing any added ...
Cancer 14 hours ago | not rated yet | 0
Scientists have uncovered a survival mechanism that occurs in breast cells that have just turned premalignant-cells on the cusp between normalcy and cancers-which may lead to new methods of stopping tumors.
Cancer 15 hours ago | not rated yet | 0 |
(Medical Xpress)—Regulating the distribution of power in neurons is done by a system that makes the national electric grid look simple by comparison. Each neuron has several thousand mitochondria confined ...
9 hours ago | 4.8 / 5 (5) | 0 |
A brief visual task can predict IQ, according to a new study. This surprisingly simple exercise measures the brain's unconscious ability to filter out visual movement. The study shows that individuals whose ...
15 hours ago | 4.5 / 5 (10) | 1 |
Teams of highly respected Alzheimer's researchers failed to replicate what appeared to be breakthrough results for the treatment of this brain disease when they were published last year in the journal Science.
13 hours ago | 5 / 5 (1) | 2 |
Scientists at the National Institutes of Health report they have discovered in mouse studies that a small molecule released in the spinal cord triggers a process that is later experienced in the brain as ...
13 hours ago | 5 / 5 (2) | 0 |
Little is known about why asthma develops, how it constricts the airway or why response to treatments varies between patients. Now, a team of researchers at Weill Cornell Medical College, Columbia University Medical Center ...
13 hours ago | not rated yet | 0 |
Ethnic background plays a surprisingly large role in how diabetes develops on a cellular level, according to two new studies led by researchers at the Stanford University School of Medicine.
11 hours ago | not rated yet | 0 |