Addendum May 23, 1972, to Testimony Regarding Use of Simazine In Los Angeles County

G. A. Heidbreder, M.D., M.P.H.

Health Officer, Chairman

Hearing Committee

Board of Supervisors

Los Angeles County

Dear Doctor Heidbreder:

Enclosed you will find evidence from, as yet, unpublished animal studies made by the Bionetics Research Laboratories, Inc., of Bethesda, Maryland, between 1966 and 1968. These proved that the chemicals mentioned below are definitely carcinogenic for the rat strains used. Other studies disclosed that all of these chemicals tested were also teratogenic. Most of the photocopies concern carcinogenic studies but I can provide you with further teratogenic studies if you so request.

Simazine is definitely carcinogenic and without doubt, teratogenic since triazine was a potent agent for producing birth deformities in animals.

Other chemicals tested include 2,4-D; 2,4-D Isopropyl Ester; 2,4-D Isooctyl Ester; 2-(2,4-DP); 2,4,5-T; 2-(2,4,5-Trichlorophenoxy) propionic acid (Silvex): 2,4,5-Trichlorophenol; p’p DDT; p’p and o’p DDD; Sevin; Atrazine; and Zectran.

All of these chemicals produced tumors–many of them malignant–in most animal species which were subjected to experimentation. It is quite interesting that these chemicals, in many instances, also caused focal pneumonia, probably of a chemical or a virus type. This finding may help to explain the increasing incidence of so-called virus pneumonia or virus pneumonitis in human beings which has been noted over the past 20 years.

It should be noted that all of the phenoxy herbicides, Simazine, Atrazine, and Propazine, as well as Sevin, Chlorobenzolate, Thiodan, Minex, Captan, Calcium Cyanamide, and Cacodylic Acid are carcinogenic. All of those tested are also teratogenic.

Silvex, Triazine, 2,4-D, and Zectran are more potent carcinogens than 2,4,5-T. Interestingly enough, there were six studies with 2,4-D and all tests showed tumor production and deformities. It is curious that only 2,4,5-T was singled out by the Federal Government for restricted use, even though it does not appear to be as dangerous as 2,4-D, nor as Silvex, which produced more tumors than 2,4,5-T or 2,4-D. It should be noted that 2-(2,4-DP) which the U. S. Forest Service is substituting for 2,4,5-T is more toxic than the chemical which it may be displacing. It should also be noted that Zectran, which is being used in large amounts in another state on their forest preserves in place of 2,4,5-T, is one of the most toxic herbicides in the carbamate classification since experiments with only 10 mg., as compared with 400 mg. for one of the other herbicides, are effective in producing both tumors and birth deformities. These facts exemplify the adage that “a little knowledge is a dangerous thing”.

It is also of considerable interest that p’p DDT and DDD were definitely carcinogenic for some of the strains of rats used in the experiments. Since the amount of 2,4-D used is thirty to fifty times that of 2,4,5-T and since 2,4-D has been authorized for use on food crops for many, many years–in fact since the late 1940’s–I believe that this herbicide constitutes one of our great hazards and that your committee and the Board of Supervisors must meet it.

It seems to me this information is sufficient for your committee to recommend to the Board of Supervisors that the sale and use of all herbicides in Los Angeles County be completely banned. Such courageous action in an attempt to protect the health of all citizens might set an example for other areas throughout the country.

To my mind, it makes no sense to lock the door after the television has been stolen. It makes much more sense to take action along preventive lines, rather than to wait for a pandemic of cancer–such as occurred in our trout hatcheries about ten years ago. In that instance, since the life of a trout is comparatively short, clever epidemiological studies finally revealed that the cancer inducing agent was in the cottonseed meal, which was common to most foods on which trout were raised. It was finally identified as aflatoxin.

In the case of human beings, a cancer pandemic might be the beginning of the end for civilization since, except for primitives, individuals would have been exposed to carcinogenic chemicals–together with poor nutrition–over a period of ten to 20 years before the outbreak of such a possible cancer epidemic. In view of the comparatively long life of human beings, epidemiological studies would be too late at that time to save the population. I am sure that with your knowledge of epidemiology you can appreciate this fact.

Recent studies have shown that about twenty per cent of water supplies sampled in 1970 throughout the country contained traces of the phenoxy herbicides. Even though the amounts were small, in my opinion, any amount of these herbicides in the water supply is too much. This is simply an indication of the widespread contamination which is occurring from the use of these chemicals.

The U.S. Forestry Service is continuing to use 2,4-D, 2,4,5-T, and, at times, Silvex and 2,4-DP, as well as other pesticides in our national forests, which constitute the watersheds of the coastal areas of California. I would urge that water supplies up and down the coast, derived from the Pacific aspect of the coastal ranges, be tested for pesticides. I would also suggest that supervisors up and down the coast consult with the State Department of Agriculture concerning the possibility of stopping the use of these herbicides in Los Padres National Forest, since drift from helicopter spraying and potential contamination of our water supply render these activities a real danger to our citizens.

Whereas I well understand some of the implications involved in the banning of herbicides throughout Los Angeles County, I feel that the health of our citizens is primary and feel sure that you share my concern in this regard. I sincerely hope that the information which I have given to you will be helpful.

Respectfully yours,

Granville F. Knight, M.D.