How am I Affected by Toxins?
Fortunately, we are seldom exposed to sufficiently large doses of chemicals to suffer acute toxic effects. In most circumstances, a person is regularly exposed to a substance at levels significantly below the acutely toxic level. This is called chronic exposure.
Tobacco smoke, present in many homes, contains many toxic chemicals. However, most exposure to tobacco smoke does not result in instant mortality because the levels of exposure are below the acutely toxic level. Over time though, toxic effects from tobacco smoke become more evident. The effects are most visible in smokers suffering emphysema; lung, nose and throat cancer; and other chronic ailments. Evidence is mounting that non-smokers who live or work in smoke-filled environments also suffer chronic effects.
Many people who are exposed to the variety of chemicals in our environment do not reach acute toxic exposure which leads to cancer or death. However, they may experience an array of subtle symptoms, including headaches, rashes, or breathing difficulties, which, while less dramatic, can be extremely debilitating. Compounding this problem is the difficulty of isolating which chemical present in your home, office or even car is causing the problem. Multiple chemical sensitivity is poorly understood and, therefore, hard to cure.
Measuring the risks associated with chronic exposure to chemicals is no less difficult. The best data comes from occupational exposure to chemicals that result in unique malignancies. For example, chimney sweeps in 19th century England developed cancer of the scrotum much more frequently than the general population. We now know this was due to exposure to polynuclear aromatic hydrocarbons in the soot with which they had daily contact. Similarly, lung cancers in shipyard workers implicated asbestos as a carcinogen, as did liver cancers in workers manufacturing polyvinyl chloride (PVC), as well as a rare cancer that causes tumors to grow inside the liver's blood. Incidence among vinyl chloride workers of this form of cancer is 3,000 times higher than among the general population.
There are strong links between increased cancer rates and life in the industrialized world, where we are exposed to high levels of suspected cancer-causing chemicals. A 15 year study in Oregon, comparing women who didn't work outside the home with women who did, found a 54% higher death rate from cancer in the women who stayed home. The study suggested that chronic exposure to cleaning products played a role.
In Sandra Steingraber's outstanding book Living Downstream, she documents some powerful information:
Breast cancer rates are 30 times higher in the United States than in parts of Africa.
The International Agency for Research on Cancer has concluded that 80% of all cancer is attributable to environmental influences (these include lifestyle influences such as smoking, as well as exposure to carcinogenic chemicals).
During our lifetime, 40% of all Americans will get some form of cancer - 50% of men and 30% of women.
One-half of the world's cancers occur among people in industrialized countries, even though these people are only one-fifth of the world's population.
Amazingly, only a dozen or so chemicals have been directly implicated in human cancers. Most of the other "suspected" carcinogens have been identified by feeding large doses of these chemicals to specially bred mice and rats. If a chemical produces tumors in one or more feeding studies, it is only considered a suspected carcinogen.
The problem of extrapolating results of animal studies (high levels of exposure for short periods of time) to human exposure (low levels of exposure for long periods of time) has not yet been satisfactorily resolved for two reasons. First, because research methods don't accurately mirror the way ordinary people use a chemical in the "real world," it is difficult to assess potential problems that may exist with many of the chemicals we use every day.
If, for example, you ingest a pound of chemical X in a single sitting, one can safely assume that you will sicken and die. But what happens when you're exposed to just a few thousandths of a gram of chemical X every day for many, many years? Regulators who evaluate cancer risk assume the risk of cancer from exposure to a chemical decreases as one is exposed to less of the chemical, but that the risk is never zero. They set standards for exposure that attempt to assure that no more than one person in a million is likely to die of cancer when exposed to these chemicals.
The second reason our research is unsatisfying is that whenever the test results come close to suggesting a certain chemical is dangerous enough to be removed from the market, the chemical's manufacturer is likely to spend millions, if not hundreds of millions of dollars challenging the government's research. Claiming, in the case of dioxin for example, that even though hundreds of tests and studies indicate that dioxin does cause cancer, no actual tests were done on humans (and, of course, never will be), so we’ll never know for sure!