Sunday, October 11, 2009

Plastics and Global Warming

Cheryl Holdren gave a presentation about plastics, pollution, and maybe what we can do about it, the sixth in a series, "Stewardship and the Planet," addressing world economic and ecological problems. A little over half of the audience was from my church, which is where I found out about the series.

Cheryl's talk addressed ubiquitous pollution and its impacts, focusing particularly on BPA (bisphenol A) which is common in plastics such as milk containers, water bottles, food packaging. These items often end up not only in landfills, but also in woods and lakes, rivers and streams, and the oceans. They slowly degrade, releasing BPA and other chemicals into the environment. The health impacts have been documented for many years, and are now being piled higher and deeper. In 2008 annual sales of BPA were $6 billion. In April 2008 Canadian health officials began to take steps to declare BPA a toxin and to have it banned from use in baby bottles and tableware for children. In August 2008 the FDA declared BPA to be safe. In October 2008 the FDA's Science Board found that the FDA had ignored hundreds of studies on BPA and advised the organization to re-open its investigation.

Some of the impacts that have been documented are altered behavior due to early childhood exposure, altered neural development in rodents, heart disease, lowered effectiveness in chemotherapy, prostate and neural development in human fetuses. It seemed to me that there was something wrong here with the posture our society takes, requiring the research community to prove that there is a problem with the many new chemicals that are introduced each year, or the chemicals will remain used in the marketplace. This is in direct contradiction with the FDA practice for pharma and medical devices, in which the burden of proof is on the developer and manufacturer to demonstrate safety and efficacy. Cheryl confirmed that the FDA is now looking into regulation and legislation to place such a posture in to place.

I am going to think a little out loud below about the possible positive feedback loops that her talk may have revealed between such pollution and global warming.

1. As the pollutants leach out from plastics, a key one being bisphenol A, they pollute the water. This leads many people to believe that they must be even more reliant on bottled water. This in turn leads to more production of plastic bottles, more transportation of bottles and water, which leads to greater pollution of the water. Further, this production of plastic for the bottles is energy intensive, contributing to global warming.

2. As our culture uses more water, this resource becomes more precious, and it may become more costly (in dollars, in energy, in atmospheric carbon) to produce and deliver to users. An extreme example of this is the historic use of pure drinking water from Navajo acquifers to provide the water for a coal slurry line to an electric power plant in Northern Arizona. Several years ago some MIT students spent a summer on the reservation documenting the sink holes that resulted. As water from this shallower acquifer is overused, there is environmental degradation, and it becomes more costly to obtain water. This in turn leads to the need for more power to obtain that water. In the case of Hull MA and nearby, there is a shortage of potable water. The apparent answer is desalinization. Although the historic technology for this uses electrical energy produced by petrochemical power plants, Hull is working toward desalinization using wind power, and approach which could break the positive feedback loop if it is successful.

3. As global warming continues and more carbon dioxide is absorbed by lakes and oceans, the ocean water becomes more acidic. This increases the leaching of toxic chemicals from plastics already in the waters, again leading people that they must consume bottled water rather than tap water. Cheryl's comment about bottled water is that it may not be any better or even as good as tap water. The caveat in my hypothesis here is that there may be very little increase in leaching for the small pH changes actually occurring in water.

More later.

No comments: