[unclear: st]term salient printed an article on the[unclear: mical]herbicide, 2.4,5-T. The firm that[unclear: mrkets]this chemical, Ivon Watkins-Dow[unclear: d]recently wrote to us seeking an[unclear: portunity]to present their views on the[unclear: mtinued]use of this chemical. Their article[unclear: m-xvrs]below.

Since its introduction in 1948, 2,4,5-T [unclear: s] been a mainstay in the battle to [unclear: lectively] control trees, brush and weeds [unclear: Itich] threaten the growth of rice, conifer [unclear: iafs], or rangeland grass; and which [unclear: late] hazardous situations on road [unclear: Mulders] and utility rights-of-way. During [unclear: s] period, the toxicity of 2,4,5-T has been [unclear: liaustively] studied by scientists worldwide. [unclear: c] great majority of these scientists agree [unclear: n] it is not hazardous to human or animal [unclear: I] under normal conditions of use and [unclear: i] under conditions of substantial [unclear: suse].

This enviable safety record doesn't count [unclear: h] special interest groups which oppose [unclear: e] use of virtually any of modern [unclear: riculture's] chemical tools. They have [unclear: en] exerting strong pressure to have 2,4,5- [unclear: oanned].

Their reasons range from the [unclear: otic]—"man-made chemicals defile other Earth" (letter to California [unclear: rtment] of Agriculture); to the [unclear: minal]—herbicides sprayed on the deep [unclear: tods] destroy marijuana crops hidden [unclear: are] (editorial in Agrichemical Age, May 1978.)

These groups, representing Vietnam War [unclear: otestors], anti-technologists and the Environmentalism Cause", don't [unclear: iderstand,] or care, that there often is no [unclear: bstitute] for a given chemical. And they [unclear: rtainly] will not acknowledge that without [unclear: rtilizers] and pesticides as much as one- [unclear: rth] of the world's population would [unclear: arve] (U.N. Food Conference 1974.)

You should know that for every [unclear: flammatory] charge from the "anti's" [unclear: ere] is a rational explanation; for every TV newspaper hatchet job, there is a [unclear: mplete] rebuttal.

[unclear: he] Benefits

The joint assessment team of the [unclear: epartment] of Agriculture, EPA and the [unclear: tate] Land Grant Universities has [unclear: rtermined] the economic loss of 2,4,5-T [unclear: ould] be;

[unclear: orestry]—$801 million cumulative net [unclear: come] loss at the end of 10 years;

[unclear: asture] and Range—$347.5 million [unclear: mulative] loss to producers at the end of 6 years;

[unclear: jghts]-of-Way—$33.9 million increase in [unclear: nnual] vegetation management costs;

[unclear: ice]—$33 million cumulative yield and [unclear: uality] losses, plus control cost increases at [unclear: leend] of six years.

[unclear: CDD]

This compound, 2,3,7,8-. [unclear: Hrachlorodibenzo]-p-dioxin, is one of a [unclear: amily] of compounds known as dioxins. It [unclear: i] formed in the manufacture of the [unclear: richlorophenol] used to make 2,4,5-T. Although it has not been feasible to [unclear: ompletely] eliminate TCDD, it is present in [unclear: ommercia] supplies in less than five parts [unclear: ier] 100 million parts of 2,4,5-T (equivalent to one inch in 320 miles).

TCDD is one of the most toxic chemicals known—an emotionally charged statement which obscures the fact that the amount present in agricultural pesticides is not enough to endanger human health or to affect plants or animals in the environment.

For instance: A report of the Council for Agricultural Science and Technology states that to get a lethal dose, an 80-kg (175 lb) animal with the sensitivity of a rat would have to comsume all of the treated vegetation on more than 400 acres of land.

Dioxins from Combustion

Dow USA Michigan Division researchers have announced the discovery that the 75- member family of chlorinated dioxins (including TCDD) occurs naturally as a consequence of the combustion of a variety of fuels and other common materials, may have done so as long as there has been fire, and is occurring today throughout the world.

The discovery occurred when Dow researchers tried but could not scientifically nor logically link the discovery of TCDD found in fish to pesticide production at Midland, and therefore had to look for a less obvious source of dioxin. We do not yet fully understand the significance of the Michigan Division discovery as it relates to pesticides. We know that when we search for TCDD in an environment exposed to 2,4,5-T we do not find measurable amounts; and that when we search for TCDD and other chlor-dioxins in an environment exposed to large sources of fuel combustion we do find measurable amounts. Possible explanations for this diffirence are being discussed, but a firm answer still lies in the future.

Agent Orange-Veterans' Lawsuits

Emotional charges have been made that wartime use of chemical defoliants in Vietnam may have resulted, or some day will result, in increased numbers of birth defects in the children of Vietnam veterans and / or in health problems for veterans themselves. This is not a new charge. It was fully explored by a committee selected by the National Academy of Sciences in 1974. The committee's report concluded that there was "no conclusive evidence of association between exposure to herbicides and birth defects in humans in South Vietnam."

The major constituents of Agent Orange—2,4,5-T (containing trace amounts of TCDD) and 2,4-D—have been the subjects of thousands of scientific papers and technical articles over a 30-year span. These studies show that the phenoxy herbicides are not significantly hazardous to human or animal life under normal conditions of use and even under conditions of substantial misuse.

Twenty-two lawsuits on behalf of Vietnam veterans now have been filed against Dow and five other global corporations that produced Agent Orange. The suits charge negligence on the part of the manufacturers. They are being contested vigorously.

Alsea, Oregon

A number of independent experts have examined the Alsea study and determined that EPA's conclusions are not valid for the following reasons:

The number of live births and spontaneous abortions claimed for the Alsea and control areas were not obtained by correct procedures and therefore, the spontaneous abortion indices calculated were not indicative of the true situation.

The statistical procedures used for the analysis of the data and the conclusions reached were invalid and not indicative of the true situation.

There was no evidence in the report of any exposure of the women involved to 2,4,5-T or TCDD since only one half to two square miles were sprayed each year out of a 1600- square-mile area investigated for abortions. In fact, of the ten women whose abortions made up the "June peak", all ten lived 20 to 50 miles upwind of the spray area studied.

The conclusions by these independent experts indicated no evidence of a link between 2,4,5-T and spontaneous abortions in the Alsea area. Studies by the Australian and New Zealand governments confirm these conclusions.

Seveso, Italy

In 1976 at Seveso, Italy, the worst exposure of a human population to TCDD occurred as a result of an accident in a nearby plant making 2,4,5-trichlorophenol. It was estimated that approximately 1,000 grams of TCDD was released during the accident and that 300-500 grams was deposited in Zone A, the most contaminated Zone. 147.5 grams of TCDD was found in the soil of Zone A after the accident. No one in the area was killed. The only injuries observed—other than caustic soda skin burns—were the typical acnegenic lesions caused by TCDD on about three percent of the children. There was no indication of excessive abnormalities in the offspring of exposed mothers; there was no excess of spontaneous abortions; examinations of foetuses from both spontaneous and deliberate abortions showed no indication of increased abnormalities.

By comparison, the maximum amount of TCDD applied in any one year to a treated square mile in the Alsea area was approximately 25 mg or 1/20,000th of the amount of TCDD found in the soil of the most contaminated zone at Seveso. Since at the most only one half percent of the Alsea basin sampled for abortions was actually treated with 2,4,5-T the exposure to TCDD at Seveso was at the very least millions of times greater than the exposure at Alsea. It is obvious that the conclusions arrived at by the EPA from the Alsea study are invalid.

Birth Defects Human Health

The use of 2,4,5-T is not hazardous to human health. The technical product itself is about half as toxic as caffeine, twice as toxic as aspirin, and about 10 times as toxic as salt. 2,4,5-T is not found either in our food or drinking water, but if it did occur at the most sensitive levels of detection, the acute toxicity safety margin would be at least two million.

Conventional applications of 2,4,5-T will not cause cancer. 2,4,5-T is not a carcinogen. TCDD is a weak carcinogen causing cancer in rats only when given amounts sufficient to produce severe, easily discernable toxicity. Since TCDD is not a mutagen, it will not be a carcinogen at nontoxic concentrations. Even when inappropriately regarded as having no safe level with respect to carcinogenicity, the probability of 2,4,5-T causing cancer (as calculated by the methods currently employed by EPA) is much less than from drinking diet soda or eating peanut butter. Specifically, the risk of contracting cancer from 2,4.5-T calculated for a backpack sprayer working five days a week for 30 years is about one chance in 2,500,000. This risk is about 1/25th the risk from drinking one diet soda per day (exposure to saccharin), and 1/100th the risk from eating four tablespoons of peanut butter per day (exposure to aflatoxin.)

The highest exposure to 2,4,5-T during conventional use is that of a backpack sprayer. The safety margin with respect to fetotoxicity for a female backpack sprayer is in excess of 500. The safety margin for accidental exposure to a Conventional 2,4,5- T spray is approximately 17,500. By contrast, the safety margin for normal consumption of aspirin is three, and for Vitamin A, it is 40.

The Environment

Neither 2,4,5-T nor the contaminant TCDD in the product persists or accumulates in the environment and they do not occur in either food or drinking water. They can only be detected in the environment at the locations where 2,4,5-T is sprayed for a short period of time after application. As applied in commercial formulations, TCDD has been found to have half-life on vegetation of 6-8 hours due to ultraviolet degradation.

All of our research and all of our knowledge continue to demonstrate that 2,4,5-T is not hazardous to human or animal life under normal conditions of use and even under conditions of substantial misuse. Despite the claims of EPA in its emergency suspension, there still is no documented instance of human injury' from normal uses of 2,4,5-T (containing trace amounts of TCDD) because humans are not exposed to toxicologically significant amounts. The 6-7 million pounds of 2,4.5-T used in the US each year contain between one and eight ounces of TCDD and it is spread over five million acres. We should be able to understand this low hazard because we know that carbon 'monoxide in auto exhaust is extremely toxic yet we control the hazard by limiting our exposure.