At five months, Hillary Tucker finds herself at the bitter end of the food chain.

Hillary has an infantile cancer called neuroblastoma and needs all the nutrition she can get to ward off infection. But she is denied the important antibodies passed in breast-feeding because her mother's milk is laced with a potentially carcinogenic pesticide.

"I thought she was getting benefits from my milk," said Hillary's mother, Jane Tucker. "Then, it began to dawn on me that I was poisoning her."

Hillary's plight is just one of the human costs of a dairy milk contamination crisis sweeping the Southwest. The toxic pesticide tainting her mother's milk originated in the feed of dairy cows in Arkansas, Oklahoma and Missouri, then speedily moved up the food chain of people consuming dairy products.

Milk, the pure essence of motherhood sold commercially as "fitness you can drink," is polluted -- right in the heart of dairy country.

Officials have traced the contaminated feed to a small gasohol dealer in northwest Arkansas who allegedly used grain treated with a banned pesticide -- heptachlor -- in his distillery process. He then sold the toxic residue to farmers at cut-rate prices. In the past month, the consequences of that small business venture have shaken the economic foundations of the rich dairy belt flanked by the Ozark Mountains, and have radiated to eight neighboring states where truckloads of milk and ice cream have been yanked off the shelves and tested for heptachlor contamination.

Dairy farmers and processors have had to dump millions of gallons of "hot" milk tracked down by official sleuths.

Herds of nearly 50 dairy farmers, mostly in Arkansas, have been "quarantined" by state governments. Prohibited from selling their milk or cows, many farmers confront what Steve Baugh, part owner of the Triple B Dairy in northwest Arkansas, said is the daily trauma of "watching everything you own, everything that your family has ever worked for going down the drain with that milk."

Last week, there were indications that the contamination has spread to the region's meat supply. The Agriculture Department embargoed meat shipments to school lunch programs after inspectors found heptachlor-tainted beef and pork in Arkansas and Oklahoma slaughterhouses.

The public health impact of heptachlor contamination is a subject of intense debate. But after high levels of heptachlor began showing up in the breast milk of dozens of women in the Tuckers' tiny town of Eureka Springs and other parts of Arkansas, state health officials warned that heptachlor lodges in fatty tissue, such as breasts, and recommended that nursing mothers turn to formula for infants.

Heptachlor is known to cause cancer in laboratory rodents. Toxicologists say it can only harm adults if consumed in large quantities. But it presents a greater risk to infants because of their immature immune systems and their total dependency on milk.

Most agricultural uses of the once-popular pesticide were banned in 1978 after it was identified as a probable human carcinogen. Almost all of heptachlor's other purposes were phased out by July 1983, but farmers and wholesalers were permitted to exhaust their existing stocks.

It was from those stocks that Jack E. White acquired hundreds of tons of heptachlor-coated grain seed for a small gasohol plant he opened in Van Buren, Ark., in 1980, according to federal and state investigators.

White fermented and distilled the seed in a tangle of pipes and vats, leaving a soupy residue called mash. Officials said he advertised the toxic byproduct as nutritious cattle feed and sold it to farmers within 100 miles of Van Buren at prices as low as one-third of the grain normally fed to dairy cows.

Records of White's company, J.E.W. Inc., were too sketchy for investigators to determine how long he had been selling contaminated mash. Officials say they only have solid evidence of sales in January and February of this year.

According to farmers, White began offering the waste product in the winter of 1983 for $60 per ton, then slashed the price to $45 this past winter.

"You just got to cut corners when you can," said Baugh, who used the mash to feed his herd in the past three winters. "Our cows loved it. They'd tear the fence down to get at it. They gave good milk on it. We got tricked real bad."

White, a self-made millionaire who dropped out of school after the sixth grade, is serving a 90-day sentence in an Arkansas jail for fraud in connection with a bank loan.

In an interview from jail published in the Van Buren Press Argus-Courier March 13, White said he used corn seeds in his fermentation process but did not know the grain had been treated with heptachlor. He said the grain broker from whom he bought the seeds failed to properly label the product as required by federal law.

"There was no attempt to deceive anyone," he told the newspaper. "It wasn't supposed to have heptachlor."

But the grain broker has a different recollection. Tom Enders, New Orleans office manager for Greater Northern Commodities Co., told the Van Buren newspaper that White's firm "knew what it was getting. When you get one-third to one-half discount and it comes in pink, there is no question in anybody's mind what it is.

"If a deal looks too good, it isn't," Enders said.

Pink-colored seeds normally serve as a flashing yellow light to agriculture workers. According to federal regulations, pesticide-treated grain must be dyed an unnatural color -- pink or bright green -- as a warning against animal and human consumption.

The pinkish hue of White's mash should have alerted dairy farmers who now claim to be victims, according to James R. McClellan, the chief Food and Drug Administration enforcer in Arkansas and Louisiana.

"That stuff was obviously pink, red, whatever," said McClellan. "Some of them farmers should have known better."

Actually, the first clue of heptachlor contamination came from an Arkansas farmer who spotted the off-color grain at White's outlet in January. He called the state Plant Board, which regulates cattle feed, and asked whether the mash could hurt his dairy cows.

State inspectors tested the mash for pesticides Jan. 27, but they found no contamination. The FDA, meanwhile, had heard that the mash was contaminated with another toxin and inspected White's plant in early February. The results came in Feb. 24: the feed was soaked with heptachlor.

White's feed operation was immediately shut down, and federal and state inspectors launched an all-out detective hunt for cattle that had consumed the spiked mash. Their search extended to hundreds of dairy farms straddling the borders of Arkansas, Missouri and Oklahoma, close to the Van Buren plant.

Inspectors combed White's spotty records and found receipts for 26 dairy farms.

Since heptachlor shows up in the milk of cows, inspectors followed the commercial path of milk. They focused on "haulers" who pick up milk from eight to 10 farmers every day, comingle it in large refrigerated tanks and deliver it to processors.

"When we'd get a hot truckload," said Tom Butler, an Arkansas health department official, "we'd send out men to check all the dairies on his route that day. You could have one bad dairy and seven good ones in the batch. We knew one of them was hot. So everybody was quarantined till we got back their test samples."

At one point, 117 of Arkansas' 1,200 dairy farms were quarantined, and heptachlor levels in milk reached 120 times the maximum levels the FDA allowed.

It was also possible to identify processors with contaminated milk by tracing "hot" haulers to them. Goldstar Dairy, Arkansas' largest processor, has had to dump 175,000 gallons of milk, said general manager S.W. Lynn, who estimated a loss of $300,000.

The trail of contaminated milk led inspectors selling contaminated mash. Officials say they only have solid evidence of sales in January and February of this year.

According to farmers, White began offering the waste product in the winter of 1983 for $60 per ton, then slashed the price to $45 this past winter.

"You just got to cut corners when you can," said Baugh, who used the mash to feed his herd in the past three winters. "Our cows loved it. They'd tear the fence down to get at it. They gave good milk on it. We got tricked real bad."

White, a self-made millionaire who dropped out of school after the sixth grade, is serving a 90-day sentence in an Arkansas jail for fraud in connection with a bank loan.

In an interview from jail published in the Van Buren Press Argus-Courier March 13, White said he used corn seeds in his fermentation process but did not know the grain had been treated with heptachlor. He said the grain broker from whom he bought the seeds failed to properly label the product as required by federal law.

"There was no attempt to deceive anyone," he told the newspaper. "It wasn't supposed to have heptachlor."

But the grain broker has a different recollection. Tom Enders, New Orleans office manager for Greater Northern Commodities Co., told the Van Buren newspaper that White's firm "knew what it was getting. When you get one-third to one-half discount and it comes in pink, there is no question in anybody's mind what it is.

"If a deal looks too good, it isn't," Enders said.

Pink-colored seeds normally serve as a flashing yellow light to agriculture workers. According to federal regulations, pesticide-treated grain must be dyed an unnatural color -- pink or bright green -- as a warning against animal and human consumption.

The pinkish hue of White's mash should have alerted dairy farmers who now claim to be victims, according to James R. McClellan, the chief Food and Drug Administration enforcer in Arkansas and Louisiana.

"That stuff was obviously pink, red, whatever," said McClellan. "Some of them farmers should have known better."

Actually, the first clue of heptachlor contamination came from an Arkansas farmer who spotted the off-color grain at White's outlet in January. He called the state Plant Board, which regulates cattle feed, and asked whether the mash could hurt his dairy cows.

State inspectors tested the mash for pesticides Jan. 27, but they found no contamination. The FDA, meanwhile, had heard that the mash was contaminated with another toxin and inspected White's plant in early February. The results came in Feb. 24: the feed was soaked with heptachlor.

White's feed operation was immediately shut down, and federal and state inspectors launched an all-out detective hunt for cattle that had consumed the spiked mash. Their search extended to hundreds of dairy farms straddling the borders of Arkansas, Missouri and Oklahoma, close to the Van Buren plant.

Inspectors combed White's spotty records and found receipts for 26 dairy farms.

Since heptachlor shows up in the milk of cows, inspectors followed the commercial path of milk. They focused on "haulers" who pick up milk from eight to 10 farmers every day, comingle it in large refrigerated tanks and deliver it to processors.

"When we'd get a hot truckload," said Tom Butler, an Arkansas health department official, "we'd send out men to check all the dairies on his route that day. You could have one bad dairy and seven good ones in the batch. We knew one of them was hot. So everybody was quarantined till we got back their test samples."

At one point, 117 of Arkansas' 1,200 dairy farms were quarantined, and heptachlor levels in milk reached 120 times the maximum levels the FDA allowed.

It was also possible to identify processors with contaminated milk by tracing "hot" haulers to them. Goldstar Dairy, Arkansas' largest processor, has had to dump 175,000 gallons of milk, said general manager S.W. Lynn, who estimated a loss of $300,000.

The trail of contaminated milk led inspectors next to grocery stores that received their dairy products from "hot" processors. By last week, ice cream samples were being tested as far away as St. Louis.

Officials reported a 50 percent fall in demand for dairy products in some areas. In Eureka Springs, a town of 2,000 people located on the rim of Arkansas' dairy belt, grocery stores put up signs assuring customers that their milk came from nonquarantined dairies.

"There is a ripple effect," said Mike Masterson, special assistant to Agriculture Secretary Richard E. Lyng, who led a task force to Arkansas in mid-March. "The economic misery is spreading to the entire industry."

The misery index is high at the Baugh farm in Lincoln, Ark., 160 acres of rolling farmland where 136 dairy cows once earned $15,000 a month. Since their herd was quarantined Feb. 25, the Baughs have no source of income. At the same time, they have to pay their bills of $13,000 a month, feed their cows and "milk out" the pesticide. Every day, they drain 500 gallons of milk into barrels for later disposal. And, if toxicologists are right, the dumping will have to continue for at least six months before their dairy cows are purged of heptachlor.

Baugh, 28, who works the farm with his father and brother, said that unless the family gets federal assistance, the Triple B Dairy will be "history" in a matter of days. "We've got a little bit of money left between us," he said. "We can choose to feed our families with it or our cows."

Baugh said the mash he bought was never pinkish. Moreover, he said, he acquired the feed knowing that "we have government agencies that are supposed to protect us against these things."

As breast milk tests began turning up heptahlor counts twice the safe levels set by the FDA, officials advised pregnant women, nursing mothers and infants to drink dry milk. The state has offered free testing of breast milk and sent special kits to nursing mothers to prepare samples. Hundreds of women have responded, but test results have not been released.

Jane Tucker, 36, the Eureka Springs mother whose breast milk test showed heptachlor concentrations two times higher than the FDA's standard, is desperately trying to purge herself of the chemical with an electric breast pump so that she can eventually nurse Hillary back to health.

"The more I pump, the faster I detoxify myself," said Tucker, who realizes that cleansing her system may take months. "Breast milk is the best thing for her."