Subject: Historical Midland County Birth Defects
Date: 1965 - 2003
Discussion of Hypothesis Formation
by Charles Poole
More than sifficient data exist in the experimental and epidemiologic literature to support the generation of the hypothesis that human exposure to TCDD increases the risk of bearing malformed offspring. The more specific hypothesis that exposure within or near Dow's Midland facility between 1970 and 1973 increased this risk emerges from the following information.
In a critique of an EPA study of spontaneous abortions in Oregon associated with the spraying of 2,4,5-T
(1), Dow scientists employed data from a hospital in Midland, Michigan, as a control for the Oregon study area.
In the course of EPA's inquiry into the suitability as a control area, data and information arose on birth defects in Midland County. These data warrant further exploration.
During the period 1965-1070, the ratio of total congenital malformations to live births in Midland County was comparable to that for the whole state of Michigan.
(2) In 1971, however, the ratio rose precipitously to a peak more than three times higher than the state figure. The ratio remained elevated until 1975, when it declined to a level again comparable to the statewide total.
In 1972 and 1973, Midland County's rate was the highest in the state
(3) Dr. Gerald Rice, cCief of the Michigan Bureau of Personal Services, in a letter to mr. Todd Mason of the Midland Daily News, stated his opinion that the increase in the overall rate was due to increased reporting of "minor deformities"
(4) No criteria for distinguishing "minor" birth defects from "major" ones were stated in the Michigan Department of Public Health (MDPH) materials received by EPA thus far, but a newspaper article by Mr. Mason supplied by Dow
(5) Cites water-filled scrota, undescended testes, slight heart murmers, webbed or deformed toes and certain skin or muscle defects as falling into the "minor" category.
The MDPH also supplied figures for expected cases based on state rates for three specific types of birth defects; CLEFT LIP AND PLATE, UROGENITAL DEFECTS, AND HEART ANOMALIES (6) (6) The table below lists the results, which show all three types to be in significant excess during the 1970-1974 period. It is important to note that malformations falling into each of these categories, especially CLEFT LIP AND PALATE, have also been observed in the animal experiments testing the teratogenicity of TCDD.
It is possible that some of the "minor" defects listed in Mr. Mason's article contributed to the excesses seen in this table for urogenital and heart defects. No information has been made available, however, which would distinguish between increased reporting of these "minor" defects and their increased occurence. The article, written in 1976, reported that, although local hospital staff regarded reporting as "more thorough than in the past," they could remember "no formal change in reporting policy or practice"
(5) Cases of CLEFT LIP AND PALATE, the most commonly observed malformations in the animal studies of TCDD, are never classified as "minor" anomalies.
An important point is that increased reporting of birth defects in Midland beginning in 1971 would not explain the subsequent decline seen in Figure 1 to a level which by 1975 was comparable to that of the state in general.
The possibility exists that some environmental factor in the Midland County area was responsible for the observed peak in birth defects in that area. The consistency of the specific types of anomalies in excess with those seen in animal studies help to raise TCDD as a candidate.
A second newspaper article by Mr. Mason outlined Dow's 1976 plans to study this increase
(8) Dr. H.C. Scharnweber, Dow's medical director, stated that the company would send registered nurses to interview the wives of workers engaged in the manufacture of 2,4,5-T and pentachlorophenol. The interviews were to focus on spontaneous abortions and congenital malformations. On May 23, 1979, a Dow spokesperson described this study as "still in progress"
Dow's unpublished report, "The Trace Chemistries of Fire - A Source of and Routes for the Entry of Chlorinated Dioxins into the Environment," (10) was submitted to the EPA under the requirements of Section 8 (e) of the Toxic Substances Control act, "Notice to the Administrator of Substantial Risk." One of Dow's conclusions, based upon their sampling and analysis, was that "Michigan Division pesticide production facilities are not measurable sources of the trace levels of dioxins found in fish taken from the Tittabawassee River"
(10) EPA's status report on this submission, however, disagreed with this conclusion
(11) Pointing out that dioxin was found in fish downstream, but not upstream, of Dow's Midland plant, the status report concluded that " THE AVAILABLE INFORMATION..CONTINUES TO SUGGEST THAT DOW CHEMICAL COMPANY'S MIDLAND, MICHIGAN PLANT REPRESENTS THE MAJOR, IF NOT THE ONLY, SOURCE OF TCDD CONTAMINATION FOUND IN THE TITTABAWASSEE RIVERS AND SAGINAW BAY IN MICHIGAN"
(11) Noting also that "THE LEVELS OF POLYCHLORINATED DIBENZODIOXINS FOUND IN MIDLAND ARE 2-4 ORDERS OF MAGNITUDE GREATER THAN THOSE REPORTED AT OTHER LOCATIONS," the EPA evaluation characterized THE MIDLAND AREA AS A "DEFINITE TCDD ' HOT SPOT'"
No data or information on production volume, manufacturing processes, or possible environmental release of TCDD during the late 1960's and early 1970's were included in Dow's report. EPA information specialists have been asked to request such information from Dow. It is known that Dow was a major supplier of TCDD-contaminated herbicides, primarily mixtures containing 2,4,5-T, used in massive quantities during the war in Vietnam. It was reported that around 1968, Dow installed a device which removed TCDD from the 2,4,5-trichlorophenol (TCP) used as a feedstock for 2,4,5-T production, lowering the TCDD concentration in TCP from 10-25 ppm to less than 1 ppm (12)
It was shortly after the announcement in April 1970, of the suspension of certain 2,4,5-T uses by the Secretaries of Agriculture, Interior, and Health Education and Welfare that the Department of Defense decided to abandon the use of 2,4,5-T as a defoliant in Vietnam (13) These decisions were in response to recently reported animal studies of the teratogenicity of TCDD.
It is also know that during the week preceding June 26, 1970, Dow export shipments from Bay City set a new record of six million pounds in five ships bound for " Europe, Latin America and the Far East " (14) Dow also announced at that time that shipments were 35 % ahead of the previous year
(14) It was not until September of 1970 that Dow announced final completion of an $800,000 diversion system to keep spills of organic chemicals out of the Tittabawassee River and to "contain any spills within the Midland facility"
(15) The possibly accelerated production and shipment activity in the spring and early summer of 1970 at Dow's Midland plant, coupled with the installation of spill-containment capabilities in the fall of that year, suggest that a significant release of TCDD into the Midland County environment during 1970 might have been possible. This possibility needs to be more fully explored.
Note: Charles Poole testified (re: Midland) before the United States House of Representatives Science and Technology Committee, Subcommittee on Natural Resources, Agricultural Research and the Environment on March 23, 1983.
At that time Poole was a doctoral student in epidemiology at the Harvard School of Public Health.
Background: 1976 Master of Public Health degree from the University of North Carolina, worked in Washington, DC for the White House Council on Environmental Quality. In February, 1978 he joined the staff at the EPA office of Toxic Substances.
Personal Note: My husband and I moved to Midland in the spring of 1977. My son was an infant and my daughter was just beginning kindergarten. We lived on the Northeast side of Midland. In the mid-nineties my children left Midland and moved to California.
My grandson Caleb was born in Orange County, California almost 2 years ago with a Cleft Palate.
His birth defect would not be listed in the Midland County statistics.
How many others have left Midland County and delivered babies with birth defects ?
We need a National Birth Defect Registry.
The same question can be asked about Midland cancers.
Midland County health professionals and Dow cannot legitimitely claim that " Midland is a healthy community" until they are able to track residents who lived in Midland most of their lives, yet died, or had babies with birth defects in other states or counties.
I would suggest that it is time to review the Midland County birth defect data again.
Source: Diane Hebert
For additional articles like this one, go to the Tittabawasse River Watch web site www.trwnews.net. for complete coverage of the Tittabawassee River Dow Chemical dioxin contamination saga.. The source organization's web site link is listed above. The Newspaper / Media page of our site contains an extensive archive of media articles dating back to January 2002. The Newspaper / Media page may be accessed by scrolling down to the bottom of the CONTENTS section and clicking on the Newspaper/Media link.