Cancer environmental causes

Effects of indoor air pollutants on humans are essentially the same as those described in Chapter 7. However, there can be some additional pollutant exposures in the indoor environment that are not common in the ambient setting. From the listing in Table 23-1, radon exposures indoors present a radiation hazard for the development of lung cancer. Environmental tobacco smoke has been found to cause lung cancer and other respiratory diseases. Biological agents such as molds and other toxins may be a more likely exposure hazard indoors than outside. 

The primary goal of the Childhood Cancer Research Program is to identify environmental factors responsible for childhood cancer. Specific aims are to understand the interactions between environmental causes of childhood cancer and host factors that influence reaction to environmental exposure. 

To identify new or provide more detailed evaluation of known environmental causes of adult cancer. 

In the debate about the toxic effects of dyes and chemicals, there is no doubt that carcinogenic effects are perceived by the general public as the most threatening. Chemicals remain a focus for this concern in spite of the weight of evidence that they make only a minor contribution to the incidence of cancer [60,67,83]. The generally accepted estimate of cancer causation, based on mortality statistics, indicates that only 4% of all cancer deaths are attributable to occupational exposure. Another 2% are considered to arise from environmental causes and 1% from other forms of exposure to industrial products. 

It has been proposed that in as many as 70-80% of the cases of human cancer environmental chemicals are the causative factors (JL). There is no reason why similar estimates would not be valid for animals. It is noteworthy that the occurrence of chemical carcinogens is widespread in the aquatic environment. For example, of the PAH s, BP is found in the concentration of 50 to 100 yg/m3 in what is considered moderately polluted surface water in waste water as much as 100,000 yg/m3 has been measured (6l). Several... 

No doubt the greatest environmental threat to the skin is not chemical, but is rather a physical agent, sunlight most skin cancers are caused by excessive exposure to ultraviolet radiation from the sun. 

Among the most eminent men in cancer research are many others who share Dr. Hueper s belief that malignant diseases can be reduced significantly by determined efforts to identify the environmental causes and to eliminate them or reduce their impact. 

It is not entirely clear what Doll meant by the last phrase, but he may have been referring to an increasingly dominant view that some individuals are genetically predisposed to developing cancer when they become exposed to environmental causes. In any case, his brief, informal remarks which we have quoted at length provide an excellent synopsis of the history and basis for what we shall now discuss. We shall also be discussing methods used to estimate the luck (chance, or risk) Doll mentions. 

Shields PG, Harris CC. 1990. Environmental causes of cancer. Med Clin North Am 74 263-277. 

Careful research has weakened assertions that environmental chemicals are endocrine disruptors and major causes of cancer. Environmental organizations still tout the risks to raise the public s awareness—they say—and to solicit contributions. Government officials, in charge of programs to investigate the risks, continue to provide funds to scientists who look for evidence to support the assertions and to programs that test chemicals for effects that have little, at best, and more likely, no, relationship to human health. Environmental organizations publicity and gov-... 

In the late 1970s, there was a noticeable change in the policymakers general attitude as questions arose about environmental causes of cancer, and the Swedish government commissioned a group of Sweden s most prominent scientists, led by the Nobel... 

The majority, or as much as 70-90%, of human cancers have been associated with environmental causes ( 1, 2) Our environment is complex. Cancer causes are often misunderstood and misconstrued as consisting primarily of ubiquitous chemicals due to modern technology and industrial development. It is true that a number of food additives, pesticides, insecticides and industrial chemicals introduced commercially in the last 40 years have exhibited carcinogenic properties in animal models ( 3). However, most of the main human cancers in the Western world do not stem from such chemical contaminants. It is, therefore, important to identify the actual causes of cancer in developing an effective basis for cancer prevention. 

Tornqvist, M., and L. Ehrenberg. 2001. Estimation of cancer risk caused by environmental chemicals based on in vivo dose measurement. J. Environ. Pathol. Toxicol. Oncol. 

The same experiences as obtained with drugs in different populations apply principally to environmental chemicals. This opens new prospects for the investigation of environmentally caused intoxications, including cancer. 

Childhood cancers that may have environmental causes... 

Ionizing radiation is a known environmental cause of female breast cancer. Breast cancer risk is significantly elevated in female survivors of the atomic bombings at Hiroshima and Nagasaki, but varies significantly depending on age at the time of radiation exposure. Relative risk at estimated exposure levels of 1 Sv was approximately 3-4 for women exposed before 10 years of age or between 10 and 20 years of age, but decreased to approximately 2 in women irradiated between 20 and 40 years of age and decreased even further in women exposed after 40 years of age (Boice et al., 1996). 

Davis D, et al. (1993) Medical hypothesis xenoestrogens as preventable causes of breast cancer. Environmental Health Perspectives 101 372-377. 

Powers himself is much more careful to balance his equation. For a start, it is never clear in Gain whether Laura s ultimately terminal illness is really coimected to Clare products at all. As Don presses Laura to sue, she insists that there is no reason to believe that her cancer has environmental causes. When Don tells her that she is part of a cluster centered on Lacewood, she points out that ovarian cancer doesn t cluster . She is... 

According to recent epidemiological studies, the majority of cancer cases derive from environmental causes, whose factors are attributed to either the indoor environment or outdoor air pollution and soil contamination (Doll and Peto 1981). In deed, the relative risk of lung cancer mortality increases by some 8—27% in heavily polluted areas (Beeson et al. 1998). Ghazaouet city homes the complex of non-ferrous metals (En-Metanof) which uses the pyrometallurgical process. It uses 100000-115000 t/year of raw material for polymetallic sulphide (El Abed blend), and produces 30000-40000 t/year of Zn, 100-150 t/year of Cd and 50000-80000 t/year of H2SO4. 

Soto AM, Sonnenschein C (2010) Environmental causes of cancer endocrine disrupters as carcinogens. Nature Reviews Endocrinology 6 (7) 363-370. 

Cancer is caused either by the inheritance of an abnormal gene, or exposure to an environmental agent acting either directly or indirectly on the cell genes. 

Whatever be the mechanism(s) for cancer development, one thing is clear cancer is a largely environmentally caused disease. Three studies point this fact out dramatically. 

The accident at the Three Mile Island (TMI) plant in Pennsylvania in 1979 led to many safety and environmental improvements (4—6). No harm from radiation resulted to TMI workers, to the pubHc, or to the environment (7,8), although the accident caused the loss of a 2 x 10 investment. The accident at the Chernobyl plant in the Ukraine in 1986, on the other hand, caused the deaths of 31 workers from high doses of radiation, increased the chance of cancer later in life for thousands of people, and led to radioactive contamination of large areas. This latter accident was unique to Soviet-sponsored nuclear power. The Soviet-designed Chemobyl-type reactors did not have the intrinsic protection against a mnaway power excursion that is requited in the test of the world, not was there a containment building (9—11). 

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