| Much has been written about pesticides and | | | | Other Pesticides: Other pesticides including endosulfan, |
| pollutants as being major contributors to cancers | | | | toxaphene and dieldrin have been implicated as |
| today. According to the National Toxicology Program | | | | causing breast cancer based on animal studies, but |
| at the U.S. Department of Health and Human | | | | their contribution to human breast cancer is unclear. |
| Services, there are 52 chemicals known to contribute | | | | Commercial Product Chemicals: A long list of chemicals |
| to cancers of all kinds in humans and 176 chemicals | | | | found in common commercial products have been |
| reasonably anticipated to be human carcinogens. Lung | | | | implicated in breast cancer. This list includes industrial |
| and mammary cancers are the most common types | | | | solvents (trichloroethylene, toluene and benzene), |
| of cancers that are found in animal based studies of | | | | plastic water bottles and baby bottles (bisphenol-A), |
| potential carcinogens. Despite this data, most experts | | | | and polyvinyl chloride, a ubiquitous chemical found in |
| believe that more relevant environmental risks involve | | | | food packaging, medical products, appliances, cars |
| diet, lifestyle, and factors related to a prolonged | | | | and toys. Again, the significance of their contribution |
| exposure to estrogens. However, a brief discussion | | | | to human breast cancer is unclear. |
| of some proven and unproven chemicals associated | | | | Pollutants: A very well studied group of chemicals |
| with breast cancer risk is worthwhile. | | | | collectively called polycyclic aromatic hydrocarbons |
| Smoking: Researchers from Albert Einstein College of | | | | (PAHs) have also been implicated in breast cancer. |
| Medicine in New York examined the association | | | | The most common sources of these chemicals |
| between cigarette smoking and incidence of breast | | | | include charbroiled meat, cigarette smoke, car |
| cancer in a cohort of women who had smoked for | | | | exhaust, and burning fuel. |
| up to 40 years. The women were subsequently | | | | Radiation exposure: Mounting evidence suggests that |
| followed for an average of 10.6 years. Their risk of | | | | X-ray and gamma-ray exposure may be a significant |
| breast cancer was 60% higher than that of women | | | | and causative factor, particularly if the exposure is |
| who had never smoked. Among those who smoked | | | | during childhood or early adulthood. Radiation therapy |
| 20 cigarettes or more a day for 40 years, the | | | | done for Tuberculosis and dermatologic conditions |
| increased risk rose to an 83% increase. | | | | and radiation exposure from atomic bombs have |
| DDT: DDT and its metabolite DDE are weakly | | | | been proven to cause breast cancer. The most |
| estrogenic organochlorine pesticides that accumulate | | | | important factor in radiation exposure is the dose of |
| in the food chain and collect in human adipose tissues | | | | radiation. This is why efforts have been made to |
| through the consumption of animal products. Although | | | | decrease the radiation from mammograms by 10-fold. |
| several studies showed no link when blood DDT | | | | The energy level of the radiation may also be |
| levels were checked many years after exposure, a | | | | important. Several epidemiologic studies have shown |
| recent study based on samples from blood collected | | | | an increased risk of breast cancer among female |
| during perinatal periods showed that women heavily | | | | airline attendants (1.9 fold increased risk). The likely |
| exposed to the pesticide DDT during childhood are | | | | cause for airline attendant's increased cancer risk is |
| five times as likely to develop breast cancer later in | | | | exposure to cosmic radiation (neutrons and gamma |
| life. | | | | rays), which have much higher energy than X-rays. |