Medical Mystery Probed : ‘Cancer Clusters’ Jolt 2 San Joaquin Valley Towns
McFARLAND, Calif.--Saddened already because a neighbor’s 3-year-old daughter had cancer, Connie Rosales was stunned when doctors told her two years ago that her strapping teen-age son Randy also had a form of the dread disease.
“Then somebody told me that a boy two blocks away had cancer too. That was three cases in just a few weeks,” Rosales said in a recent interview. She began asking questions and learned of two more childhood cancers. “I realized then that something was terribly wrong. McFarland is only a small town.”
Since Rosales learned that her son had cancer, doctors have diagnosed six more cases in this Kern County farming town of 6,400 people, bringing the total to 11 children who contracted nine different kinds of cancer between 1981 and 1984, a number four times the expected cancer rate, according to the state’s chief cancer epidemiologist.
Eighty miles to the north, in the tiny Fresno County city of Fowler (population 3,048), three children developed leukemia during the same period, making this the second suspected “cancer cluster” reported in the San Joaquin Valley this summer.
In addition, unusually high numbers of miscarriages, fetal deaths and low-birth-weight babies have been reported by doctors in both towns, a combination of circumstances so unusual that officials have ordered extensive investigations in each community to try to find what is causing such health problems.
Epidemiologists are searching for common exposure patterns, questioning every household to see if there are more cancers. They are taking soil samples and testing the water and air. But they warn that coming up with answers will be difficult, if not impossible.
The occurrence of a cancer cluster can usually be explained by chance alone. But Dr. Donald Austin, chief cancer epidemiologist for the California Department of Health Services, said the “McFarland cluster is real,” meaning he believes that it was caused by factors other than chance. He said the discovery of so many cancers of different kinds is “highly unusual” and suggests that there may be more than one cause.
In the case of Fowler, however, Austin said it has not yet been determined whether a true cluster exists.
Just why cancer is striking a disproportionate number of children in McFarland and Fowler is a mystery, but county and state health experts say they suspect that toxic chemicals in the water supply may be to blame.
Two Possible Agents
The high number of birth defects and cancer incidents “are strong signposts” that something in the environment is causing the problems, according to Dr. Richard Whitfield, deputy Kern County health director, adding, “There is a great deal of concern about the safety of water supplies.”
Health officials have pinpointed two possible agents: nitrates that seep into underground water supplies after farmers apply nitrogen fertilizers, and pesticides that have been injected into the soil and are later detected in well water.
McFarland’s water comes from aquifers that have long been contaminated by high nitrate levels. For two decades, officials have warned mothers not to let their infants drink McFarland’s water because it causes methemoglobinemia, a blood disorder commonly called the “blue baby syndrome.”
Nitrates can also form “carcinogenic nitrosamines” when ingested. These are substances that have caused stomach cancers in laboratory animals, according to a 1982 Kern County Health Department “ground-water quality report.”
While officials report that no pesticides were detected in McFarland’s water in recent tests, county and state health experts warn that such routine tests are capable of detecting no more than a handful of the 15,000 pesticides registered for use on state crops.
In Fowler, only one type of cancer has been found, and some officials suspect it could have been caused by two similar pesticides that were once widely used as soil fumigants.
Residues of these pesticides, 1,2-dichloropropane (DCP) and its controversial cousin, 1,2-dibromochloropropane (DBCP), have been found in wells in and around Fowler. Traces of a solvent, perchloroethylene (PCE), were also in the city’s wells. All three have been found to cause cancers in laboratory animals.
DBCP Use Suspended
After a quarter of a century of heavy use, all applications of DBCP were suspended in 1977 when it was discovered that most of the chemical workers manufacturing the pesticide were sterile. Laboratory tests showed that DBCP is a very powerful carcinogen. Health experts began detecting alarming amounts of DBCP in Central Valley aquifers in 1979, causing them to order more than 100 domestic wells shut down.
A 1982 epidemiological study in Fresno County by the state health department showed a significant increase in the incidence of stomach cancer and leukemia in communities where DBCP was detected in the water supply. No follow-up studies have been done to show if there is a cause-and-effect link between the pesticide and the cancer.
The reported clusters in McFarland and Fowler have prompted some state officials to speculate that the San Joaquin Valley, or perhaps the entire state, is at risk from ground-water contamination.
“What we see in McFarland and Fowler may be only the tip of the iceberg,” said Lt. Gov. Leo McCarthy in a telephone interview. He noted that 2,500 Californians die each year because of suspected toxic chemical-related cancers.
“McFarland and Fowler are warning flags,” said Ronald Oshima, head of the California Department of Food and Agriculture’s environmental hazards evaluation unit.
Adding its own warning, the Assembly office of research said last spring, “California’s underground drinking water supplies are endangered by toxic contaminants.
“No one knows the extent of the contamination” because the state’s testing systems do not detect “most of the newer chemicals,” an earlier report by the same office stated.
No Complete Listing
In addition, Oshima said, the state does not even have a complete list of the industrial and agricultural chemicals in use--a situation he finds “scary.”
Fifty-seven pesticides have been detected in California’s ground-water supplies, 20 of them in Fresno County and 14 in Kern County, according to the 1985 office of research report, entitled “The Leaching Fields.”
After sampling 709 water systems throughout the state, health officials reported that one well in five is contaminated by low levels of toxic chemicals. “This shows that toxics are getting into the ground water, not just by chance in a unique, random way, but routinely, in a real pattern,” said Assemblyman Lloyd G. Connelly (D-Sacramento), author of the law that requires the testing. “It may not be the water that is causing the problem in McFarland or Fowler--it could be any number of potential causes--but these things must be investigated.” Officials say the task of determining the extent of the problem is hindered by the absence of a cancer registry. Had such a register existed in Fresno County, the suspected Fowler cluster would have been verified or disproved by now, according to the state health department’s Austin. A cancer register is an early warning system requiring doctors to report each diagnosed cancer by type and location.
“Without such a formal surveillance mechanism we are in the dark. We have no way of knowing whether or not similar problems exist in other counties of the valley,” Austin said. Last year, Gov. George Deukmejian vetoed a measure that would have created a statewide cancer registry. A spokesman for his office said the governor is willing to fund registries only in 11 counties (including Kern and Fresno) to see if the concept proves effective.
Since no cancer register existed, the McFarland and Fowler childhood cancer clusters were detected only after parents of cancer victims began comparing notes.
Even then it was not easy to get officials to pay attention, according to Rosales, whose son’s case is in remission after extensive chemotherapy. “When I went to the county health back in 1983 all I got was a shrug. They said, ‘That’s the way it goes.’ ” said Teresa Buentello, whose 4-year-old daughter, Tresa, died of cancer last year. “The city and the county told us it was a coincidence, but we didn’t accept that, because it was our kids.”
County and state officials acknowledge that they did not initially recognize that a cancer cluster was developing in McFarland. A year ago, the county asked the state health department to finance an epidemiological study, but state officials turned down the request for lack of funds.
The mothers persuaded state Sen. Art Torres (D-South Pasadena), chairman of the Senate Committee on Toxics and Public Safety Management, to hold hearings in McFarland in July.
“Nobody did anything for us, not until Sen. Torres had that hearing. Then after all the publicity, they (county and state health officials) started doing something,” Buentello said.
The Kern County Board of Supervisors declared that McFarland had a “public health emergency,” and state health officials made $40,000 available for a full-scale epidemiological investigation.
The McFarland hearings caught the attention of Pat Shepherd, the mother of a cancer victim in Fowler, who persuaded Fresno County officials to launch their own study of the cancer cases there. Shepherd had two miscarriages and a stillbirth before she had Jennifer, 5, who has leukemia.
County Health Director Don Cobb said that pesticides such as DBCP are only “one part of the puzzle in Fowler. There are a whole bunch of things we must look at.”
In McFarland, just over half of the affected families live within a few blocks of each other, having purchased new homes in a subdivision built in 1980. Most of the fathers work on nearby farms.
“We’re concerned about the cancers, and we know the water is the prime suspect,” said Fred J. Hass, president of the McFarland Mutual Water District, which supplies these families. He pointed out that nitrates had not been linked to human cancer, even though “they do show cancers in the stomach of rats.”
Nitrates Scrubbed From Water
Financed by a federal grant, the district recently built a $300,000-filtration plant that scrubs most of the nitrates out of the water.
Not everyone in McFarland, however, believes there is a problem. Hardware store owner Albert Wasson blames the media, saying: “We didn’t have any trouble here before this got in the news. I had cancer. They took out most of my stomach, but I don’t think it was the water that did it, it was stress.”
News of the cancer cluster did have another unfortunate effect, according to law enforcement officials who are investigating possible fraud in the sale of “cancer filters” to 50 homeowners. Each family paid $2,250 for a unit to be hooked up to its water taps.
“There’s no way those units can filter cancer out of water,” said Terry Hilliar of the Bakersfield Better Business Bureau. Many of the Spanish-speaking homeowners who signed $67-a-month-payment contracts written in English did not realize that they had put a lien against their homes, he said.
Several parents of McFarland cancer victims complain that state and local officials are moving too slowly. They filed suit last month in Kern County Superior Court seeking unspecified damages from six chemical companies as defendants.
“How many more of our children must die before something is done?” asked Rosemary Esparza, whose son, Adrian, 5, is the latest McFarland child diagnosed. “I want (health officials) to hurry up and get over here and find out what is doing this to our children.”