8.9: Cancer
- Page ID
- 212717
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Cancer
One of the leading causes of death in the United States is cancer. Cancer is actually a group of diseases that are characterized by an out-of-control growth of specific body cells that erode life functions. Of the many varieties of the disease, skin cancer is the most common among Americans. It is clearly associated with overexposure to the ultraviolet light from the sun and from tanning beds. Lung cancer kills more Americans than any other type of cancer, and about 90% of lung cancer fatalities are associated with smoking tobacco. Smoking also causes a host of other deadly cancers. Other behavioral factors linked to cancer involve alcohol, weight control, and dietary practices. Cancer is not contagious, but many cancers display spatial patterns similar to infectious diseases. Geographers study cancer and their techniques offer insights into both behavioral and environmental causes of cancer, and as a result – insights into strategies to combat cancer.
Figure : US Map – The overall cancer rate is highest in Southern and Appalachian States where cultural behaviors elevate the risk of getting cancer. Source: CDC Cancer Atlas.
Cool Map:
Interactive Cancer Atlas from the Centers for Disease Control and Prevention
Allows users to map a variety of cancers by state, ethnicity, and sex.
Some cancers are associated with ethnicity or national heritage. Partly this is because some cancers are inherited. Some forms of breast cancer, for example, are clearly inherited, prompting numerous women with a family history of breast cancer to undo preventative mastectomy surgery. Because genetics traits are often shared among groups of people living in a region, ethnic or national groups often have genetic anomalies predisposing them to specific types of cancer. For example, studies have found that the rate of stomach cancer is above average for Finns and Koreans and that liver cancer for Vietnamese men is higher than other groups. However, because ethnicity and national origins also predict many cultural and economic practices, it is difficult to statistically determine causality. Children who are adopted by people from a different ethnic group, or people who move beyond their ethnic homelands are often studied by medical geographers because such people help separate genetic causes from cultural ones.
Exposure to environmental pollutants is also linked to certain cancers, making geographic methods indispensable in the search for causes and preventative measures. Unlike the national or state maps of cancer showing general trends occurring within arbitrary boundaries, maps plotting cancer clusters at regional or neighborhood levels can be compelling.
Consider, for example, mesothelioma, a rare type of lung cancer that showed signs of geographic clustering in the 1960s. By mapping mesothelioma clusters and various types of industry, researchers saw that locations where asbestos was mined and processed had much higher rates of the mesothelioma than regions where mining and processing asbestos was absent. This finding later allowed biomedical researchers to establish a causal relationship between various lung diseases and prolonged exposure to asbestos fibers.
Figure : Baton Rouge, LA - One of the largest oil refineries in the United States is located on banks of the Mississippi River where transportation advantages accrue. Related industries cluster nearby. What are the health effects of this cluster of petro-chemical industries on the health of Louisianans? Source: Wikimedia
Cancer Cluster – Cancer Alley:
The most famous cancer cluster in America, an area known as Cancer Alley, may not be a cluster at all. The gap between perception and reality here highlights the difficulty of identifying the environmental causes of cancer. Cancer Alley lies along the Mississippi River in Louisiana between Baton Rouge and New Orleans and shares territory with a significant number of petrochemical factories.
Clearly, this corridor does have one of the highest cancer rates in the United States, but because “Cancer Alley” does not have a statistically significant greater cancer rate versus other parts of Louisiana health geographers doubt that the region is actually a cancer cluster, and doubt that the factories are the cause. Unhealthy lifestyles, poverty and poor access to affordable, high-quality health care both within and beyond this industrial corridor make it difficult to separate the effect of the petrochemical industry on cancer rates from the effects of poverty and unhealthy lifestyles that characterize the entire region.
Figure : Niagara Falls, NY – The Love Canal neighborhood stands abandoned after toxic waste from a landfill was found in the local soil and water in the 1970s. Source: Wikimedia.
Some health problems, such as birth defects, asthma, and miscarriages, are easier to connect to exposure to toxic chemicals. The most well-known toxic pollution site in America is Love Canal, a neighborhood once home to some 900 families near Niagara Falls. It had to be abandoned in the mid-1970s after hundreds of residents were sickened by thousands of tons of toxic chemicals that had been buried nearby 20 years earlier by a chemical company. Poor construction practices and lax environmental regulation allowed the chemicals to begin seeping upwards through the soil into yards and basements. The health of hundreds of residents suffered, and many conditions were found to be far more prevalent there than elsewhere – indicating that the chemicals were the cause.
In recent years, the Flint Michigan Water Crisis has brought some renewed attention to the danger of lead poisoning, a health issue that had declined greatly in the US since the government banned lead additives in paint and gasoline in the 1970s. Flint’s problem grew out of their reliance on very old city water pipes, a search for a cheap source of drinking water and bad mistakes by Flint’s water management team. As a result, people living in older parts of town (poor, African-American) were exposed for many months to poisoned water.