Environmental Factors Inducing Human Cancers
Environmental factors in cancer development Definition Environment as a The relationship between dietary fats and breast cancer continues to be studied. This paper gives an overview of environmental causes of cancer and the approaches of a causal relation between exposure to the agent and human cancer. Many people wonder if the environment they live in “causes cancer.” To answer . Other cause-and-effect relationships have been noted in workers between –.
Radon is a naturally occurring radioactive gas formed by the decay of uranium in rocks and soil. The gas is odorless, colorless, tasteless and cannot be detected by sight. Radon seeps up through the ground and is released into the air.
Radon gas exists at harmless levels outdoors. In areas where there is poor ventilation, such as underground mines, radon can accumulate to levels that pose a risk for the development of lung cancer. Radon causes cancer by emitting radioactive particles as it decays. These particles damage the lining of the lung when the radon is inhaled.
Individuals at highest risk for the development of cancer from radon exposure include uranium miners and those individuals who live in well-insulated, tightly sealed homes built on uranium-rich soil. Testing for radon is the only way to determine if a home has elevated radon levels. Reproductive and gynecologic factors Lifestyle choices linked to breast cancer include diet, alcohol consumptionoral contraceptives, estrogen replacement therapy, postmenopausal obesity, and nulli-parity a woman who has never had a child.
The relationship between dietary fats and breast cancer continues to be studied. Women who consume more than two alcoholic drinks per day are at higher risk. Oral contraceptive use has been linked to the development of breast cancer.
Nulliparous women who began using oral contraceptives prior to the age of 18 years and continued uninterrupted use for more than eight years have a minimally increased risk. Risk related to use of estrogen replacement therapy seems to be most significant for those women who used hormone replacement therapy prior towho used replacement therapy for eight years or more, and for who also used oral contraceptives.
Weight gain in early adulthood seems to increase risk for breast cancer, especially if the gain occurred in the third decade of life. The highest risk related to obesity and the development of breast cancer is in postmenopausal women. Full-term pregnancy seems to exert a deterrent effect on the development of breast cancer.
Women who become pregnant after the age of 30 years, or who never become pregnant, are at higher risk.
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Historically, lactation and breast-feeding have been recognized as protective mechanisms for breast cancer development. A correlation between the development of breast cancer and abortion has been documented in several studies conducted in the United States. A large study conducted in Denmark to investigate the correlation found no increased risk of breast cancer among women who had undergone abortions. Precancerous and cancerous lesions of the cervix are associated with many personal risk factors, including a higher incidence in women who become sexually active prior to age 17, have many sex partners, and are multi-parous have borne at least one living child.
An association has also been described between type of employment and increased cervical cancer mortality. Women with higher mortality rates include women once employed in farm work, manufacturing, personal services, or who worked as nurses' aides. Women who are infected with the human immunodeficiency virus HIV are at higher risk for the development of squamous intraepithelial lesions of the cervix.
Cervical cancer is not often diagnosed in women who are nulliparous, those who are lifetime celibates, or who are lifetime monogamous having sex with only one person. Psychological stress Stress is known to activate the body's endocrine or hormonal system which in turn causes changes in the immune system.
There is no specific evidence that changes in the immune system caused by stress directly cause cancer. However, the relationship between stress and the development of breast cancer has been recently studied.
Some studies report significantly higher rates of breast cancer in women who experienced stressful life events and losses in the years immediately preceding the diagnosis of breast cancer. Other studies do not support the association between stress and breast cancer development.
Cellular phone use Studies in the United States and Denmark in and revealed there is no link between cellular telephone use and tumors of the brain, salivary gland, leukemia, or other cancers. The type of telephone, the duration of the cell phone use, or age of the phone user had no effect on cancer risk.
External environment Chemicals and other substances Exposure to certain chemicals, pesticides, and metals can increase an individual's risk for cancer. Carcinogens in this category include nickel, cadmium, vinyl chloride, and benzene. These carcinogens may act alone or in combination with another carcinogen, such as cigarette smoke, to increase risk for cancer. Environmental tobacco smoke secondhand smoke Environmental tobacco smoke ETS is a combination of two forms of smoke from tobacco products— sidestream smoke and mainstream smoke.
Sidestream smoke is smoke released between puffs of a burning cigarette, cigar, or pipe.Environmental Factors Cause Cancer - Megan Kohoutek
Whenever possible, we attempt a quantification of the burden of environmental cancer in the European Union, comprising 15 countries, as of Cancer risk from environmental exposure to asbestos Asbestos and asbestiform fibres are naturally occurring fibrous silicates with an important commercial use, mainly in acoustical and thermal insulation. They can be divided into two groups: Chrysotile is the most widely used type of asbestos.
Although all types are carcinogenic to the lung and mesothelioma, the biological effects of amphiboles on the pleura and peritoneum seem to be stronger than those of chrysotile 2. The use of asbestos has been restricted or banned in many countries. In contrast to the many epidemiological studies available on asbestos-exposed workers, there are few studies on the health effects of non-occupational household and residential exposure to asbestos.
One type of household exposure concerns cohabitants of asbestos workers and arises from dust brought home on clothes. A tested hypothesis is that antioxidant vitamins may protect against cancer based on the premise that oxidative damage to DNA leads to cancer progression. Hence, preventing oxidative DNA damage would prevent progression to cancer. Fast food side effects are obesity, worker exploitation and negative health outcome 30 Most of the fast food prepared from processed ingredients which have its own benefits and risks.
Toxin removal, preservation, marketing, distribution, seasonal availability and transportation are the benefits of food processing. Using food preservers and heating can destroy the food texture prior to canning. The Federal Food, Drug and Cosmetic Act have banned the use of any food additives that might have carcinogenic effects, such as cyclamates and saccharin.
Although, the risks and benefits of food additives have been controversial. Some artificial food additives have been associated with cancer and other human diseases. Sodium nitrite which has been used for meats to produce a fresh red color to the consumer. Sodium nitrite can be converted to nitrosamines which is highly carcinogenic.
Since the food additives can absorb UV-radiation, this can aid to determine the additive concentration in a sample using external calibration.
Any method of cooking can destroy some of the food nutrients based on water content, cooking time and temperature. However, it has been well documented that microwave cooking retains most of the food micronutrients due to short exposure time.
Since microwave radiation is non-ionizing rays, it does not increase the cancer risks, as it has been shown by ionizing radiation like X-rays 32 Air and water pollution Air and water pollution is the results of biological, biochemical and atmospheric particles which cause damages to our living environment.
Air pollution is a significant risk factor for respiratory infections, cardiac disease and lung cancer. The main cause of air pollution includes particulate matter, damaged ozone, nitrogen dioxide, sulfur dioxide, carbon dioxide, carbon monoxide, ammonia, radioactive decay of radon gas, methane, hydrofluorocarbons and chlorofluorocarbons. Water pollution is caused by several pathways; 1. Microorganism infection; bacteria, viruses, protozoa and parasitic worms.
Wastes that are decomposed by oxygen-requiring bacteria by oxygen reduction leading to fish death. Acids, salts and toxic metals which cause the death of aquatic life. Water polluted by several organic compounds such as; oil, plastics, detergents, chloroform, petroleum, polychlorinated biophenyl, fertilizer, sulfur oxide, pesticides and trichloroethylene which cause various human diseases including cancer Conclusion Cancer is a complex genetic disease as a consequence of environmental exposures which serve as the driving force in initiating tumor development and progression.
The scientific literatures provide substantial evidences of environmental and occupational causes of cancer. This will fully support an accelerated effort to prevent carcinogenic exposures.
In addition to all of the evidences cited, there are many other indications that environmental exposures are linked to various human cancers. The single major risk factor for cancer is age, and the number of our geriatric people is rapidly increasing. If we look only at incident patterns among those aged 65 and 85 years old, there will be a significant increase number of cancer patients over the past 30 years.
The same is correct for other ages as well. Cancer has become a widespread disease with epidemic proportions in certain cancer sites in a single generation.
Environmental factors in cancer development
Currently, about one in four Americans could expect a cancer diagnosis at some point during his or her lifetime.
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Cancer and the Environment
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