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David Linhardt, 08/30/05, reader opinion to MDN article 08/29/05


Dr. James Collins, lead researcher on Dow's Chlorophenol Dioxin Serum study, wrote an open letter to the MDN in which he expressed his surprise that the EPA, DEQ and MDCH criticized the study. He also defended the study while taking a potshot at the DEQ and praising the EPA for seeing the errors of its ways.
A new section "Say What ??" has been added to www.mdn-rejected.com  to address Dr. Collins's letter.
I know that all of us are saddened by the sudden death of Frank Salas. Frank and Shirley would have been married 50 years this September. I am certain that all of us extend our deepest condolences to Shirley and her family.

Dave Linhardt


TRW Note: Below is a copy of Mr. Linhardt's opinion, click here to visit his site www.mdn-rejected.com to view the original and links to supporting documentation.

August 30, 2005 - Dow's PR Response to Criticism of Chlorophenol Study

In the two weeks since the publication of The Dow Chemical Company's study on dioxin serum levels in a small number of its chlorophenol workers, the study has been criticized by the EPA, the MDEQ and the MDCH and suggestions have even been made that the study is invalid.

In an open letter to the MDN, Dr. Jim Collins, principle researcher of the study, defended the study and its findings. Unfortunately, the vast majority of the readers of the MDN have never read the study and may accept some of Dr. Collins statements as fact.

A link to the Chlorophenol study, the www.DioxinSpin.com  analysis of the study and Dr. Collins' MDN letter have been provided. Readers are encouraged to read both study and analysis (perhaps in this order).

Link to Chlorophenol study: PDF Files\DOW CHLOROPHENOL BLOOD SERUM.pdf
Link to DioxinSpin analysis: PDF Files\Chlorophenol Study - Final Report.pdf
Link to Dr. Collins' MDN letter: PDF Files\JCOLLINS - MDN LTR - AUG 29 05.pdf

The following comments are offered in response in the MDN letter:

1. "We found high dioxin levels... among tradesmen... who were not formally assigned to the chlorophenol plants but whose duties sometimes required them to enter these plants."

Hair-splitting, perhaps misleading, to say the least.

Perhaps a review of the maintenance organization in the Midland plant might help put this statement into better context. Maintenance tradesmen were administratively part of the Maintenance Department but a large number of them were assigned to the chlorophenol plants on a more-or-less permanent basis. Tradesmen were often "loaned out" to other departments during plant turnarounds or when plant breakdowns required a large number of maintenance personnel for a short period of time. Following the loan-out period, tradesmen assigned to the chlorophenol plant returned to their chlorophenol responsibilities.

Unless the chlorophenol maintenance personnel spent a great deal of time in Waste Control (waste incinerators and chemical waste ponds) or Chlorobenzene (a known source of dioxins/furans), the majority of the dioxins found in their blood serum was the result of chlorophenol exposure. In order to support the supposition that substantial dioxin exposure occurred in other plants, the company will need to release the information that it surely must have on dioxin levels in Waste Control and Chlorobenzene workers.

Incidentally, the Chlorophenol tradesmen had the second highest dioxin serum levels [85.0* ppt-TEQ (16.0* - 193.0*)] in the study, second only to TCP personnel with chloracne [86.6* ppt-TEQ (11.4 - 273.0*)] (* = exceeds US population levels).

2. "We also found that our workers who did not enter the chlorophenol plants had normal background blood dioxin levels.

Only when compared to the unadjusted CDC background levels.

The CDC study has been criticized for including four abnormally high serum levels that may have been the result of unknown (or unreported) exposures to high levels of dioxins in the past. The maximum value in the range of CDC serum dioxins (146.4 ppt-TEQ) was based on a single subject. The next highest value in the same age group was 97.5 ppt-TEQ also that of a single subject.

In addition, the CDC study was based on blood serums measured in approximately 2000 while the Dow study was based on blood drawn in late 2003. Since blood serum levels are dropping with time, the Dow study should have adjusted the CDC data to 2003 levels.

When these two adjustments are made, the "comparison employees" that did not enter the chlorophenol plants had dioxin serum levels higher than US background levels in all categories, except one -- the youngest age group.

3. "... the exposure estimates used in our previous studies are very accurate, giving us a high degree of confidence in our study conclusions."

The study based this claim on data correlating dioxin Exposure Indices with blood serum levels. However, the only correlation between Dow's exposure estimates and measured serum levels is a weak correlation between H/OCDD Exposure Index and TEQ associated with H/OCDD.

The link is a chart that shows all of the TEQ versus Exposure Indices data presented in the Dow study. Based on this data, it would be very difficult to estimate serum levels based on an Exposure Index as Dr. Collins has claimed. PDF Files\TEQ-EXP INDEX.pdf

4. "To my surprise, two state agency spokesmen... were quoted criticizing our analysis..."

Perhaps, if the company hadn't delayed providing hard copies of the slides used at a verbal reporting session from December, 2004 until March, 2005, the DEQ and MDCH might not have gotten suspicious of the study.

5. "... what the state agencies failed to mention, or perhaps appreciate, is that tradesmen were not included in the comparison group..."

The DEQ and MDCH probably failed to mention it because they fully comprehended that the only tradesmen in the study were those exposed to chlorophenol dioxins and furans. The study is quite clear on this.

6. "We recommend that the few critics of our studies voice their criticism..."

Be patient... the chlorophenol study was only published two weeks ago the number of critics may grow in the future.

7. "... voice their criticism in a letter to the editor of the Journal of Exposure Analysis and Environmental Epidemiology, where our most recent paper was published."

I sense a certain amount of scientific arrogance in this statement.

Any issues that the DEQ and MDCH may have with the study must be resolved with the company there is no need for a journal to serve as a referee.

For us common folks, fat chance that a scientific journal would even read a "letter to the editor" from a writer without a PhD and a scientific or industrial affiliation. However, if Dr. Collins would like to forward my letter of constructive criticism with a recommendation that it be published, I would be glad to take pen in hand.

8. "Let the scientific community decide is their criticism is valid."

First of all, the objective scientific community rarely does anything without compensation and money is tight. Even Dow's elite group of peer-reviewers do not work free of charge. Which does bring up an interesting point : the Chlorophenol study was peer-reviewed by five outside reviewers including travel, etc., exactly how much did the peer-review cost?

Not to be critical of the motives of peer-reviewers but repeat business is hard to come by when a multi-million dollar study is lambasted.

Secondly, while scientific review does have value so surely does the review by exposed residents and exposed employees both current and past. In the end, perhaps, the opinion of potentially damaged individuals should be the company's main concern, not the praise of its scientific peers.

David Linhardt, publisher


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