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Vol. 10 Issue 4, Fall 2005

Interview with Nellie Brown: Tracking Down Exposures to Mammary Carcinogens
The Ribbon 

Nellie Brown is currently collaborating with Dr. Suzanne Snedeker to create a report titled, "Chemicals, the Workplace, and Cancer Risk." On the origins of this project, Dr. Snedeker says, "This project has grown out of the first cancer-risk database BCERF constructed, the EnviroChem and Cancer Database (ECCD). Several years ago, undergraduate Michael Goldman and computer programmer Sean Gardner worked with me to construct an interactive database on the 42 National Toxicology Program (NTP) chemicals known to cause mammary (breast) tumors in laboratory animal cancer bioassays. In our research, we found that most of these chemicals are still manufactured and used, nearly all have the potential for exposure in the workplace, and some are present in household products. Much of the data characterizing occupational exposures to chemicals are based on two surveys conducted 20-30 years ago by the National Institute for Occupational Health and Safety (NIOSH). We lacked a database that would characterize the potential for exposure to mammary carcinogens not only by occupation, but also by specific tasks. We needed to address not just potential exposures resulting from the manufacturing of the chemical and its use in making other products, but also from when the chemical is produced as a by-product or contaminant, as well as when workers are exposed during transport or even during repair of equipment and clean up operations. Our intent is to create a database that would reflect past and current exposure scenarios that could be used by workplace safety professionals. We hope to use this database as a basis of educational programs for consumers as well.

The Ribbon: What about your background and other current work make you a good match for this project?

Nellie Brown: Everything I have ever done has turned out to be relevant to this project. Currently - and for as long as I have been doing workplace health and safety programs for the School of Industrial and Labor Relations - I do a great deal of site investigations in the field involving process hazard/failure evaluations and job hazard evaluations. Through this work I am directly familiar with workplace processes that may lead to exposures, and so I can purposefully track those things down. It helps very much when you already know, for example, that in a certain process there may be vents here, leaks there, waste generated here... I do a lot of process failure analysis; that is determining where an industrial process is likely to go wrong, and therefore possibly lead to exposures.

In my employment previous to this I have worked as a wastewater treatment chemist and developed a knowledge base in biogradability, product composition and potential disposal possibilities. I became interested in whole formulations of products, not just an active ingredient or two. I began my career in limnology (the study of the biology, chemistry, and physics of fresh water) and also worked as a chemist for a coke oven battery; as a result, my experience in dealing with environmental issues, as well as my industrial process experience have proven useful for this project.

Tracking down all the possibilities for exposure to these mammary carcinogens really draws on all this experience. The project draws upon all I am and do. I feel energized when I work on it - always a good sign!

R: When you presented in Albany on September 30, you talked about a "cradle-to-cradle protocol" for examining exposure to these chemicals; can you explain this to readers?

NB: One often hears the concept of cradle-to-grave. But the fact is, there are a lot of materials that, environmentally-speaking, don't rest easily in their graves. About a year before beginning work on this project, I came across this concept of a cradle-to-cradle protocol. Actually, many industries have grown up around taking care of used materials - keeping them out of landfills by remanufacturing or reusing them. Many of the items we are dealing with in the mammary carcinogen database involve exposures in these types of industries or are themselves produced by using these processes to recycle into other products. We need to be able to capture the fact that these chemicals really stay in the system or have their origin in a place one might not normally think about. Through the cradle-to-cradle protocol, I check to make sure I have accounted for all the ways the chemical might come into being or create exposures. And this can be within all kinds of jobs, not just manufacturing.

R: Talk a bit more about the procedure you go through to complete your work on each of these chemicals.

NB: I tend to start out with two kinds of things. First, I account for various ways the chemical might come into being: sometimes it is made by natural processes, sometimes it is deliberately synthesized, sometimes it exists in a matrix such as petroleum and is separated out, sometimes it is a by-product or may not be desired but rather is a contaminant, and finally there can be de novo synthesis, such as may take place with thermal decomposition or some other chemical reaction during use.

Second, I try to capture all intentional uses and predictable misuses, and, along with these, issues of transport and disposal. I use a variety of databases, as well as books and technical references. As I do these retrievals, I may not need more than an abstract to know how a chemical might be used or present as a contaminant, and other times I need to go quite deeply into the reference source for details. Then I take each item (origin, use, transport, disposal, etc.) and put it into the appropriate industry classification categories. So these initial two tasks become my "staging area" to organize the information. The industry classifications include both the North American Industry Classification System (NAICS), which is recent, as well as the older Standard Industrial Classification (SIC) system.

Envisioning where to classify the chemical as to specific jobs and tasks is sometimes a process of thought and reflection. For example, for a compound that is in development I may need to give it a laboratory classification in addition to a manufacturing (research and development) one. And of course I have to make sure to cover transportation, unless it is one that is used where it is created.

An example of one of the mammary carcinogens with major transportation issues is benzene. It is a component in gasoline, and transported by every mode: trucks, barges, ships, pipelines, along with tank farms (area depots where material is transferred), until it reaches the point of sale (wholesale or retail). And of course emergency services (such as firefighters performing hazmat, or police handling evacuations) always come into play with transportation due to the potential for leaks, accidents, derailments, etc. on land or water, and exposures can occur with all of these occupations.

R: Have any of the exposure scenarios you have been working on surprised you? What are some examples?

NB: For me some major surprises have been those related to food and food processing, for example the use of 1,2 dichloroethane in extracting cholesterol from organ meats or to decaffeinate coffee. Fortunately there has been a move away from using organic solvents for some processes such as decaffeination. There are several of these chemicals used or formed in the manufacturing of dyes. One of them, known as C.I basic red 9 (p-Rosaniline hydrochloride) has been used for coloring apple-packing trays, as well as a tint for antifreeze and in toilet sanitary products. Another surprise for me was the use of benzene as a disinfectant in veterinary medicine. And a totally different situation for benzene exposure I have come across is in reports of it occurring (in one study) in 80% of fire scenarios, as plastics and other synthetic materials smolder.

R: You have a lot of knowledge about how changes can actually be made in the workplace with regard to reducing chemical exposures. What needs to happen? Who needs to be involved?

NB: There are a couple ways this process can be driven. Both management and the workforce need to be involved. Expertise is not only available from management, but also from people on the front lines who can have a lot of good ideas about how change can happen, with all their shop floor experience on how the processes run. And this would include both operations and maintenance; maintenance can often be overlooked. Many industrial processes have been cleaned up and made into closed systems - this can protect operators very well, so that maintenance might primarily be where exposure does occur. For example, a worker repairing a valve or cleaning up a spill may be at risk for exposure.

It is certainly helpful to have expertise applied by people in the health and safety field, and from the medical professionals. Some physicians may actually visit the workplace, while others may only get involved second hand.

Change in the workplace ideally involves all those on the shop floor, and this type of thing should be handled as any other major change in the workplace. Changing a chemical or a process can make an enormous difference, but there can be resistance. I had a situation in which a water-based material was substituted for an organic solvent, but people were bothered by the fragrance of the safer substitute. So the hazard went down, but people were resistant to the change. Change is best accomplished if employees are directly involved in helping to shape the implementation , along with good background information and training.

In looking at some of these processes where mammary carcinogens are involved, I see many examples of processes that should not be done as I am seeing them described or reported, in any case. I came across a situation in which an ethylene oxide procedure was being used for sterilization in a hospital. The sterilizer sometimes had an unventilated air gap between the discharge line and sewer such that, at the end of the sterilization cycle, the resulting backpressure could blow the sterilizer door and gases back at the operator. Ethylene oxide is still in use for medical instrument sterilization but alternatives are being brought into play.

R: You also know a lot about consumer products and their chemical contents; would you say we should be equally concerned about non-occupational exposures to mammary carcinogens? Examples?

NB: The issue for me is multiple exposures. If you are exposed to any of these things in the workplace, chances are you are going to get multiple exposures, due to the many consumer exposures you are also likely to have. For example, how do we avoid exposure to benzene in gasoline? If one only considers consumer routes, there are possibilities to try to avoid some of them. Of course we all weigh where we put our energy, with choosing alternatives and trying to stick with them. It is not easy as a consumer to individually avoid some of these chemicals. For example, with the food colorings extracted with problematic solvents: could you successfully not consume any of that coloring, anywhere? It is difficult on our own. So many of these chemicals are in such widespread use, the pressure will need to come from consumers to press manufacturers to use alternatives.

Nellie Brown, M.S., Certified Industrial Hygienist, provides training and field technical assistance statewide in occupational safety and health.

Phone: (716) 852-4191 / Fax: (716) 852-3802 / Email: njb7@cornell.edu

Cornell University, New York State School of Industrial and Labor Relations,

Suite 1200, 237 Main Street, Buffalo, New York 14203-2702

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Last Update 12.02.05