The foreword of Living Downstream provides some pretty astounding facts. At present, 45% of men and 40% of women will be diagnosed with cancer at some point in their lives. If you haven't been personally touched by cancer yet, it's only a question of time.
But the stats get even better. For instance, of the 80,000 synthetic chemicals now in use, only about 2 percent have even been tested for carcinogenicity. How many of these are we exposed to on a daily basis? What are the cumulative effects of exposure to even trace amounts of any one chemical? And if only 2% have been tested, imagine how much we don’t know about how these compounds interact. Is anyone doing anything to understand this? Sandra notes, “it is still no one’s job to make sure that the total burden of toxic exposures is not too much for any one of us.” Why is that?
A 2007 study published by the American Cancer Society identified 216 chemicals known to cause breast cancer in animals. Of these, 73 are found in food or consumer products, 35 are air pollutants and 29 are produced in the US in large amounts. Should we really be surprised at all the pink ribbons we see?
Sandra notes that the Toxics Release Inventory was launched on the internet in the mid 1990s as part of the federal right-to-know laws passed by Congress in 1986. The TRI allows the public to identify polluters within their communities and researchers to track pollution and cross-reference with cancer patterns. To understand what chemicals may exist around your home, go to Toxics Release Inventory; you can get a report by zip code or map.
Between 2001-2008 the TRI inventory was scaled back and thousands of emitting facilities were no longer required to report data. In 2009, some of the original requirements were reinstated. But the data is still less complete than in years past.
At the risk of entering politics into this discussion, I find it interesting the data required to establish scientific consensus between cause and effect was initiated in the Clinton administration, scaled back in the Bush administration, and reinstated in the Obama administration. I’m a pragmatic environmentalist a businessman, and politically independent. But I’m at a loss as to why Republican’s seem to constantly enable businesses to behave badly (the US EPA was routinely neutered during the Bush administration). Why do Republicans want to suppress the collection of data that can help the scientific community build consensus on the environmental links to cancer? Are Republicans immune to cancer?
I’m pro-business, but not if it kills my children. An economist would claim that rational economic decisions need to properly capture the externalities of production. Environmental costs are a classic example of externalities that are rarely accounted for in pricing goods and services. It’s one of the reasons why power generated from coal (large pollution externalities) is cheaper than power generated from renewable sources such as wind and solar (minimal pollution externalities). If we added the cost of cancer treatment to coal power, would it look so cheap?
But enough on that rant. Sandra notes six key trends that have recently emerged in our understanding of the environment’s contribution to cancer.
- Cancer causation is complex. It’s not just about genes and lifestyle anymore. Cancer is now thought to “result from a complex web of interwoven variables, any one of which can modify another.” I suspect that most people who get cancer (other than say lung cancer) will never know what single thing caused it, because it likely was a combination of dozens of things over many years.
- Epigenetics, the study of how substances alter gene expression, is important. Cancer can change the behavior of our genes, turning genes on or off in ways that disregulate cell growth and predispose us to cancer.
- Endocrine disruption is important. The endocrine system acts as the “hormonal messaging service that guides our development, runs our metabolism, and allows us to reproduce.” The endocrine system is easily tricked into thinking that chemicals are hormonal signals.
- The timing makes the poison. It’s not just how much exposure you’ve had, but when. Timing matters. For instance, recent research suggests that certain chemical exposures during childhood impact breast development and increase susceptibility to breast cancer later in life. A large percentage of women fighting breast cancer today grew up in the 50s, 60s, and 70s, during the heyday of rampant chemical saturation of our environment. Childhood cancer has increased steadily since 1975.
- Chemical mixes need attention. Combinations of chemicals may have consequences not predicted by one-chemical-at-a-time analysis. Yet our regulatory system considers each chemical only in isolation. This also applies to how chemicals may interact with other “stressors” on the body such as obesity or poverty. We’re flying blind here.
- The precautionary principle is gaining acceptance. The precautionary principle essentially urges us to take action to prevent harm in situations where substantive proof is unavailable. In other words, in the absence of data, we should grant the benefit of the doubt to the public health rather than the things that threaten it (eg, the petrochemical industry).
Sandra provides a good study in contrasts on the precautionary principle. The US Surgeon General issued a warning in 1964, on the basis of good but partial evidence, that smoking causes lung cancer. Yet proof of the link between smoking and lung cancer wasn’t demonstrated until 1996, more than three decades later. This was the precautionary principle in action. How many more people would have had to die if we’d waited until 1996 to act?
In contrast, Sandra cites the case of a group of chemicals called aromatic amines. A German surgeon in 1895 reported on the links between bladder cancer and aromatic amines. He had noticed bladder cancer among textile dye workers exposed to the color magenta during a time in which plant-base pigments were being replaced by coal tar-base pigments. Numerous studies were published in the ensuring century, including one in 1991 that revealed bladder cancer rates among aromatic-amine-exposed workers that were 27 times higher than normal. A paper published in 2009 cites elevated bladder cancer rates among farmers who use imazethapyr, a pesticide containing aromatic amines. Imazethapyr was registered for use in 1989 (Bush years), more than 100 years after the German surgeon identified the link to cancer. Where’s the precautionary principle there?
Another interesting observation is that “the synthetic chemicals linked to cancer largely derive from the same two sources as those responsible for climate change: petroleum and coal.” So finding ways to minimize our dependence on petroleum and coal can be considered an investment in cancer prevention.
I believe in the precautionary principle, but I’m not sure that I share Sandra's optimism that it is gaining in acceptance. Take the example of coal-fired power plants. The costs of environmental externalities (eg, cancer) resulting from coal-fired power should trump the cost of shutting down these plants or at least retrofitting older plants with modern scrubbing technology. Yet many coal-fired power plants are still granted exemptions.
For instance, Chicago has two coal-fired power plants, Fisk (built in 1903) and Crawford (built in 1924). Crawford is located within 3 miles of more than 314,000 people, 83.1% of which are non-white with a per capita income of $15,076. My kids schools are only a few miles from the Fisk plant. The plants' equipment was installed before 1976, they skirt Federal Clean Air Act regulations, and they continue to be grand-fathered by the federal government so that they are subject to more lenient pollution standards. The argument is that it would cost too much to upgrade the plants with modern technology. Yet an October 2010 study from the Environmental Law and Policy Center (where my wife, incidentally worked as an intern), estimates that the plants may be responsible for $750 million to $1 billion in public health related damages since 2002.
If some of this seems rather doom and gloom to you, you may take heart by something else Sandra notes, which is that the “mounting evidence that our environment is playing a bigger role in the story of cancer than previously supposed is good news because we can do something about it.” We can choose to shut down antiquated coal-fired power plants. We can choose to modernize our regulation of chemicals. We can insist that Congress and the President give teeth to the EPA. We can choose to support renewable energy. We can choose to buy organic foods to feed our children.
I’m struck by how the precautionary principle is also playing out in the discussion about global warming. While most of the scientific community seems to think global warming is real and is largely caused by man, there isn’t complete consensus in the underlying data and science. Meanwhile, are we doing enough to prevent global warming?
What choices are you making?
