Fundamentals of Cancer Detection, Treatment, and Prevention. Surya K. De. Читать онлайн. Newlib. NEWLIB.NET

Автор: Surya K. De
Издательство: John Wiley & Sons Limited
Серия:
Жанр произведения: Медицина
Год издания: 0
isbn: 9783527838578
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pollution is defined as the presence of poisonous chemicals or compounds (organic or inorganic) in the air we breathe, at levels that pose a health risk. Air contaminated with pollution, which can exist as particulates, biological molecules, or gases, can lead to various types of cancer [105,106]. One example is soot, which is contaminated carbon particles resulting from incomplete burning of organic material. Even as long ago as the 1770s, chimney sweeps in London were developing scrotal cancer at higher rates than in the general population. Inhalation of soot has also been linked to lung, esophageal, and bladder cancers.

      2.13.2 Certain Types of Plastic

      The safety of BPA has been controversial, as studies have found it is linked to obesity, diabetes, problems with fertility and reproductive organs, susceptibility to various cancers, and cognitive/behavioral deficits like attention deficit hyperactivity disorder (ADHD).

      While many plastic manufacturers have started labeling their products “BPA‐free,” the compound is still very commonly used in a broad array of consumer products.

      2.13.3 Acrylamide

      It is a chemical mainly used to make substances called polyacrylamide and acrylamide copolymers, which are used in several types of industrial processes, including the production of paper, dyes, and plastic. They are also found in some consumer items like caulking and food packaging.

Photo depicts browning of meat produces acrylamide and it can cause cancer. Schematic illustration of formation of acrylamide, a byproduct of Maillard reaction between reducing sugars and amino acids.

      In studies using rodent models, acrylamide exposure was linked to an increased risk of developing several types of cancer [107–117]. According to the National Toxicology Program's Report on Carcinogens, acrylamide is likely carcinogenic based on its effect in laboratory animals given drinking water contaminated with this compound. More studies, however, need to be done to find out the levels and length of exposure required to affect humans.

      A carcinogen is any substance that promotes carcinogenesis, the formation of cancer. An English physician John Hill first observed in 1761 that certain chemical exposures have been linked to the development of cancer [118]. He noted that the snuff users developed nasal cancer more frequently than the general population. Over 100 000 chemicals are used, and about 1000 new chemicals are listed each year, but not all chemicals are carcinogens. These chemicals are found in everyday items, including as foods, personal products, packaging, prescription drugs, and household and lawn care products [119–122]. While some chemicals may be harmful, not all contact with chemicals is dangerous to your health. Examples of known human carcinogens are asbestos, arsenic, benzene, beryllium, cadmium, nickel, vinyl halides, and others. Examples of possible human carcinogens are chloroform, DDT, polycyclic aromatic hydrocarbons, aromatic amines, azo dyes, nitrosamines and nitrosamides, hydrazo and azoxy compounds, carbamates, halogenated compounds, natural products, and others. DNA bases such as purine and pyrimidine are nucleophiles and react with any electrophiles resulting in DNA damage. Some reactive chemicals such as alkylating agents (alkyl halides), aldehydes, and others directly make a covalent bond with nucleophilic sites in the purine and pyrimidine rings of nucleic acids. Some chemicals react with DNA after being metabolized by the liver cytochrome P450 enzymes. For example, some alkenes and polycyclic aromatic hydrocarbons are metabolized by human liver enzymes to produce an electrophilic epoxide. DNA attacks the epoxide and is bound permanently to it and damages normal cells.

Schematic illustration of factors contributing to cancer development and their relative significance.
Women aged 20–29: Breast exam and Pap test (for cervical cancer) every 1–3 yr.
Women aged 30–39: Mammograms (X‐rays of the breast) every 1–3 yr, Pap test and HVP test every 5 yr.
Women aged 40–49: Breast test every year, Pap and HPV test every 5 yr.
Women aged 50–75:

e-mail: [email protected]

Women aged 76+: Your doctor will decide.