title: Environmental factors in causing human cancers: emphasis on tumorigenesis.
abstract: The environment and dietary factors play an essential role in the etiology of cancer. Environmental component is implicated in ~80 % of all cancers; however, the causes for certain cancers are still unknown. The potential players associated with various cancers include chemicals, heavy metals, diet, radiation, and smoking. Lifestyle habits such as smoking and alcohol consumption, exposure to certain chemicals (e.g., polycyclic aromatic hydrocarbons, organochlorines), metals and pesticides also pose risk in causing human cancers. Several studies indicated a strong association of lung cancer with the exposure to tobacco products and asbestos. The contribution of excessive sunlight, radiation, occupational exposure (e.g., painting, coal, and certain metals) is also well established in cancer. Smoking, excessive alcohol intake, consumption of an unhealthy diet, and lack of physical activity can act as risk factors for cancer and also impact the prognosis. Even though the environmental disposition is linked to cancer, the level and duration of carcinogen-exposure and associated cellular and biochemical aspects determine the actual risk. Modulations in metabolism and DNA adduct formation are considered central mechanisms in environmental carcinogenesis. This review describes the major environmental contributors in causing cancer with an emphasis on molecular aspects associated with environmental disposition in carcinogenesis.
authors.affiliation: Cancer Research Institute, MD Anderson Cancer Center Orlando, 6900 Lake Nona Blvd, Orlando, FL 32827, USA.
authors.forename: Umesh T
authors.initials: UT
authors.lastname: Sankpal
authors.forename: Hima
authors.initials: H
authors.lastname: Pius
authors.forename: Moeez
authors.initials: M
authors.lastname: Khan
authors.forename: Mohammed I
authors.initials: MI
authors.lastname: Shukoor
authors.forename: Pius
authors.initials: P
authors.lastname: Maliakal
authors.forename: Chris M
authors.initials: CM
authors.lastname: Lee
authors.forename: Maen
authors.initials: M
authors.lastname: Abdelrahim
authors.forename: Sarah F
authors.initials: SF
authors.lastname: Connelly
authors.forename: Riyaz
authors.initials: R
authors.lastname: Basha
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic; D004147:Dioxins / Q000009:adverse effects; D004781:Environmental Exposure / Q000009:adverse effects*; D006801:Humans; D008670:Metals / Q000009:adverse effects; D009183:Mycotoxins / Q000009:adverse effects; D009369:Neoplasms / Q000209:etiology*; D010575:Pesticides / Q000009:adverse effects; D011084:Polycyclic Aromatic Hydrocarbons / Q000009:adverse effects; D012907:Smoking / Q000009:adverse effects; D055549:Volatile Organic Compounds / Q000009:adverse effects
chemical_list: D004147:Dioxins; D008670:Metals; D009183:Mycotoxins; D010575:Pesticides; D011084:Polycyclic Aromatic Hydrocarbons; D055549:Volatile Organic Compounds