Letters

Hiding the CO₂ problem?

I found "Putting A Lid On Carbon Dioxide" by Jeff Johnson very informative but also quite disturbing (C&EN, Dec. 20, 2004, page 36). The Bush Administration continues its efforts to combat global warming by investing in unproven methods of sequestering CO₂--which, even if successful, may take several decades to yield any results--instead of promoting energy efficiency and development of well-proven renewable sources (such as wind and solar). This indicates that the Administration intends to continue its wasteful economic policy of "ever bigger, ever more."

It's time we realize that economic expansion and resource consumption cannot proceed indefinitely while living on Earth, which has finite dimensions and finite resources. Our present ways are not sustainable. It is necessary that we lessen our footprint on the planet. After all, it belongs not only to us but also to future generations. You can't have your cake and eat it, too.

The U.S. consumes (per dollar of gross domestic product) twice as much energy as Germany or Japan. Part of this is due to our heavy dependence on automobiles for transportation. Development of electricity-based public transportation in our cities and increasing fuel efficiency in automobiles could yield, in the short term, a considerable reduction not only in CO₂ emissions but also in emissions of NO_x and CO.

Instead of subsidizing coal and oil industries, the government should invest heavily in the development of renewable sources of energy. This not only would cut emissions of CO₂ but also provide jobs and increase independence from foreign sources of energy. I am not against the free market, but we should realize that it is not a panacea for all of our ills. Government involvement is necessary if we want to preserve a livable Earth for future generations.

Sigmund F. Zakrzewski
Clarence Center, N.Y.

Concrete explanation

I just read the article "Synthetic Chemistry Moves into Concrete" (C&EN, Oct. 11, 2004, page 22). It is informative but does not do justice to the chemical complexity of concrete.

The sentence "the polymer chemistry can be used to customize admixtures by regulating flow rate, drying time, and other variables to meet the needs of construction jobs" is particularly galling. Concrete does not dry; it hydrates. The cement grains dissolve in water, and when the resulting solution becomes supersaturated with respect to a variety of hydrous calcium aluminate hydrate and calcium silicate hydrate phases, nucleation and precipitation occur. As more hydrates form, the previously plastic and flowable concrete mixture begins to stiffen (sets) and then continues to harden for days, weeks, and even years.

Chemical additives known as water reducers strengthen concrete because they allow one to produce a flowable concrete with significantly less water than a similar mixture made without such additives. As a class of chemicals, these additives tend to alter the surface charges present on the anhydrous cement grains, which in turn causes them to repulse each other rather than agglomerate and thicken the mixture.

As the amount of water is reduced, so are the water-filled spaces between the cement grains. With smaller distances to bridge and less space to fill, a given admixture-enhanced concrete will harden and gain strength more rapidly than its more water-rich nontreated counterpart.

Michael Grutzeck
University Park, Pa.

Bhopal, 20 years later

In December, we attended a process safety conference related to the 20th anniversary of the tragedy in Bhopal, India (C&EN, Jan. 24, pages 28 and 32). After the conference, we made a trip to the Bhopal plant site.

Several "specific" causes have been offered as to why the accident occurred. We saw firsthand the plant site as it was left 20 years ago. We met with operators, a plant engineer who had left the plant before the accident, emergency response personnel, and victims. Even today, two of the more discussed "specific" causes--the water filter washing theory and the sabotage theory--are under debate. Water entered the tank, all parties agree. However, the root cause had its face showing well before this accident. Decisions were made that compromised safety control devices. This included taking two "in-series" devices out of service: The flare system was off, and the scrubber tower was placed on standby. The coolant was removed from the coolant system for the storage tanks. These were local operations management decisions.

The message is simple. During cost-cutting efforts, process safety must never be compromised, even if this means that the plant cannot be operated economically and must be shut down. And if the plant is to be shut down, process safety systems must be maintained until the shutdown is complete and all hazardous materials are removed or destroyed.

Here is some advice: Plant managers, if you have a plant with a hazard, you are responsible for managing that hazard, no matter what, until the plant is dismantled. This can include human error, mechanical failure, sabotage, or acts of God. Chief executive officers, when cost reductions are needed, you must understand that critical safety systems are not available for consideration. Educators, you must inform your students that process safety comes first. Understanding the chemistry involved and its impact on fellow employees and surrounding neighbors is just as important as being able to come up with the next breakthrough reaction or being able to size that next reactor properly.

Ronald J. Willey
Boston

Dennis Hendershot
Croydon, Pa.

Scott Berger
New York City

The two articles covering Bhopal, the status of process safety, and our international conference came out very well. On behalf of myself and the organizing committee, I wish to thank you.

It is heartening to read Tomm F. Sprick's statement that Carbide has spent more than $2 million on the cleanup of tens of thousands of pounds of methyl isocyanate (MIC) from the site of the accident. As for any MIC remaining after the tragedy of Dec. 3, 1984, it was converted into the product Carbyle by Dec. 16, 1984 (that is, within two weeks of the tragedy), with Union Carbide and Indian scientists working together and taking great precaution to avoid any release of MIC during the process. Most of the people of Bhopal had left the city by then. The product was sold by Union Carbide as per their earlier procedures. No MIC existed in the plant after this process. The whole operation was called "Operation Faith."

As for any other cleanup in Bhopal, it must not have amounted to much. The local inhabitants, as well as those active in redressal efforts, say that the company did not treat any hazardous material; they did, to some extent, lay material on the ground and put black polyethylene sheets on it (see the picture on page 31 of the Jan. 24 issue). The locals call it a "cover-up" instead of a "cleanup."

We believe that it would greatly help to know the names of the hazardous materials treated and their amounts, treatment and disposal procedures, dates of treatment, contractors' names, cost, and so on. As President Ronald Reagan once stated, with Mikhail Gorbachev at his side at the White House, "Trust, but verify." The details provided by Sprick would help establish trust and facilitate further moves. It is accepted that Dow--the new owner of Union Carbide--and the governments of Madhya Pradesh (the state in which Bhopal is located) and India are interested in early resolution of the remaining problems at the disaster site. Hence, we eagerly look forward to the information. So far, our inquiries have shown that this information is not available from any organization or through the government of Madhya Pradesh.

J. P. Gupta
Kanpur, India

More on women faculty

We are writing in response to the letter from Barbara J. Garrison et al. of Pennsylvania State University's department of chemistry regarding the percentage of women faculty in their department (C&EN, Nov. 22, 2004, page 9).

First, we applaud Penn State's record of supporting women, highlighted in the fact that four of their five most recent hires are women. However, while they rightly correct the recorded numbers of female faculty within their department, their claim of being the chemistry faculty with the highest female percentage is in error. Several years ago our department expanded its name to include "chemical biology" to reflect the long-standing research interest of our faculty. We are the only "chemistry" department at Rutgers University, New Brunswick. In addition, there are separate departments in related fields, including chemical biology, biochemistry, and pharmaceutical chemistry, at Rutgers New Brunswick. As the only New Brunswick chemistry department, and with 10 tenured women faculty out of 40 tenured or tenure-track faculty, we continue to lead in the percentage of women faculty among chemistry departments nationwide.

We add that it is positive news that 10 top-ranked chemistry departments now have female faculty percentages as high as, or in excess of, 15%. This change bodes well for the increasing influence of female chemistry faculty in research, in university administration, and in future recruitment at all levels of university endeavors in the future.

Martha Greenblatt, on behalf of Jean Baum, Helen Berman, Martha Cotter, Jane Hinch, Leslie Jimenez, Jeehuin Lee, Jing Li, Wilma Olson, and Kathryn Uhrich
New Brunswick, N.J.