Building on the overview, two weeks ago, of Nano-Safety, this week’s blog will present some thoughts from the second pillar of Nano-Safety, which is the “Impact on People and the Environment.”
There are various applications on nanotechnology that make products lighter, stronger, more durable, and able to have unique properties, like stain repellant. It is possible to acknowledge the benefits of various nanomaterials and then have a long conversation on whether the benefits are worth the risk. However, the issues of applying various nanomaterial technologies to cure serious illnesses and save lives is a different story. Lives are precious and so a greater understanding of the impact of nanomaterials on the human body is important. For instance, significant advances are being made in the treatment of cancer by employing customized molecules that incorporate nanoparticles and deliver them to cancerous sites. These specialized molecules either deliver specific chemicals or other material like gold or carbon nanotubes to the site requiring treatment. The chemicals will react with the cancer and begin destroying it. The other materials can be heated by many different methods and destroy the cancerous cells through the elevated temperatures. These approaches promise significant advances in treatment of diseases; however, the long-term impact on the body is under investigation and no definitive answers exist.
The first issue is, of course, what will be the impact on the person undergoing treatment. Will they be cured or at least put into remission? If we consider that the outcome will not be certain for 5 years, 10 years, or longer, how do we make a short term decision? In addition, since the effort is being conducted on people, the approval process for the U.S. Federal Drug Administration can take 7 or more years to obtain all approvals for a wide distribution of the process/product. Consequently, the situation exists that any development efforts can take a very long time to determine the effectiveness. So, controls are needed for the handling of these materials. The next issue that arises is what happens to the nanomaterials after they have performed their function. Fundamentally, either these particles are retained in the body or they are eliminated from the body.
If the nanomaterials are retained, the question that must be answered is the accumulation of these elements beyond a point where they themselves become toxic. There have been studies on toxicity levels and regulations by Government agencies on the maximum exposure permissible, which is significantly below the point of toxicity. As new compounds are developed, constant evaluation provides for adding information for guidance.
What about the situation where the particles are eliminated from the body? If there are environmental dangers, hopefully, the process is well contained and proper disposal is performed. Some people are alarmed that controls will not be followed and it will cause environmental damage. Yes, there needs to be an understanding of the potential environmental damage. In of itself, that is a good goal, but it is not sufficient. We, human beings, do not fully understand the working of the ecological system that is the Earth. One example of this is that the oceans naturally leak various types of petroleum. It has been found that there are microbes that live on reducing the leakage residue to a benign state. Certain type of pine trees (Bishop Pine among others) require a fire to destroy the mature trees for them to regenerate.
We need to understand the properties of nanomaterials and their effect on people and the environment. Then we can make sound judgments on the handling of the materials. But, this brings up the question, what are the nanomaterial properties? Nanosilver is known to prevent bacteria from causing infection. Bacteria appears not to be able to develop a resistance to the nanosilver as the bacteria has been able to do against modern medicines. The other side of the issue is that minute concentrations of nanosilver can be toxic to small life forms, which can be harmful to the environment. How do we determine the potential danger of materials with unknown properties?
What should be done? One answer that you will hear is any usage of the questionable material should be banned. Governments have tried that in many different ways. It drives the application and experimentation underground or to other places that do not have the ban. So that is not a good answer.
Currently, there are many industries that use materials that are considered toxic. The key to the successful application of these materials is that the workers are trained and procedures in place to reduce the potential for any accidental exposure or release of the material. But, we don’t know the potential dangers of most nanomaterials. What do we do? Next week I will discuss how to approach the process for training people to handle the unknowns of nanomaterials.