For many residents of the California gold country, the abandoned ore mills and rusting mine machinery that dot the green hills are cherished icons of a storied past.
The relics are part of the lure of the Sierra Nevada foothills, where the look and feel of the Gold Rush era has helped attract thousands of new residents, making it one of the state's fastest-growing regions in the last decade.
But these days, frightened gold country emigres are learning a modern variation on the old admonition "all that glitters is not gold." High levels of arsenic have been found in new subdivisions near several old mines, triggering a panic in one Amador County neighborhood and prompting reviews of new development plans in the Sierra.
Federal and state health officials, meanwhile, are scrambling for more information about a potential hazard that has not gotten much scientific attention.
In the Sierra, gold-bearing ore typically contains minerals rich in arsenic. Arsenic is a heavy metal that is not necessarily dangerous but that can become a human health hazard after it is pulled from the ground and exposed to the air. Chronic exposure to arsenic in certain forms can cause asthma, kidney disease and cancer.
For years, human exposure was limited to the handful of people, mostly prospectors, who came in contact with old mine tailings--the piles of sandy residue left after all the gold has been extracted. But with the population boom around here, chances of exposure are on the rise, although the risks are in dispute.
The population of almost all of the gold country counties grew by at least 40% during the 1980s. With tens of thousands of old mine sites scattered across the western flanks of the Sierra, and residential growth tracking the footsteps of the Forty-Niners into remote corners of the Mother Lode country, officials are warning that public health could be at risk.
"There are proposed subdivisions on top of or right next to mine properties from Nevada to Amador counties," said Dan Ziarkowski, a hazardous substances scientist for the California Department of Toxic Substance Control. "You've got kids using these mounds of tailings for dirt-bike tracks. And you've got the crushed rock from the tailings piles being hauled off and used for landscaping and road surfacing."
For now, the arsenic issue is getting the most attention in Amador County, where in the late 1980s a small subdivision was built in the town of Sutter Creek on top of an 11-acre tailings pile. The tailings were left by the Central Eureka Mine, which operated on and off from the 1850s until the early 1950s.
The state and federal environmental protection agencies have reported that arsenic levels in soil in and around the Mesa de Oro subdivision are high enough--about 60 times what the state considers safe--to cause serious health problems.
About 75 families live in the immediate vicinity of Mesa de Oro, but government inspectors have found elevated arsenic levels in the soil of neighborhoods up to a mile away. One of the hazards of gold mine tailings is that ore processing has reduced much of the waste to fine, flour-like particles easily spread by wind or erosion.
Federal officials say they are planning a $3-million containment project to seal the arsenic at Mesa de Oro under two feet of fresh soil. In the meantime, they have told residents not to plant gardens in the contaminated earth or let their children play in the dirt.
The Mesa de Oro investigation was touched off by a construction worker's complaint last year that he became ill digging a foundation. Although no one else has turned up sick, the arsenic findings have prompted some residents to try to sell their homes and others to rue the day they ever heard of the gold country.
"I've got $400,000, my life savings, tied up in a house I can't sell and my wife is terrified of living in," said John Pulskamp, a retired San Fernando Valley electrical engineer who moved here last year.
Hanging conspicuously in Pulskamp's home is a bulletin board on which the pictures of all the neighborhood children have been mounted next to a caption warning that the youngsters' safety is most at risk.
"My goal is to get my three little girls out of here," said Pulskamp's neighbor, Patty Sullivan. "I don't care if they tell me my driveway is clean enough to eat off."
Concern has spread to nearby Jackson, the site of two of the state's most productive 19th- and early 20th-Century gold mines. There, according to Ziarkowski, inspectors have measured arsenic up to 1,000 times what the state considers safe on a 60-acre tailings plateau where there were plans to build houses and a day-care center.
Both projects were stopped recently, he said, and a wire fence was put up around the vast, gray ridge of mine waste. But on a recent visit to the area it was clear from breaks in the fence and bicycle tire tracks on the tailings that the site has not been effectively quarantined.
"Part of the problem is the naivete of some of the newcomers," said Robert S. Borch, a UC Davis research geologist who has investigated some Amador County sites. "People are moving into those counties without any appreciation of what went on before they got there."
Sutter Creek resident Karen Guanara is a good example of the newcomer phenomenon. For three years after she moved from San Leandro, Guanara assumed that the rusty derrick on the hill above her home was a transmission tower.
She had no idea that the derrick was the head frame of the old Central Eureka Mine. Suspended from that metal scaffold, miners probed the earth 4,000 feet below, excavating ore that was crushed into a huge mound of fine powder. Over time, the mound was landscaped, subdivided and built on and today is known as Mesa de Oro.
But scientists admit that they, too, are just beginning to learn about the effects of mine tailings on human health.
"Up to now, the biggest concern has been with acid mine drainage," said Ziarkowski, referring to the toxic runoff that can foul wells and rivers, kill fish and spread impurities many miles downstream from remote mine sites.
On dry land, most of the studies on arsenic exposure have been done at smelters or pesticide fabrication facilities, said Richard Kosnett, a specialist in environmental toxicology at the University of Colorado.
"The issue of arsenic in mine tailings is a very important one to explore," Kosnett said.
It is also a difficult one, and the unanswered questions relating to arsenic in mine waste has sparked controversy in Amador County. Some people here believe that state and federal officials have shouted "fire" in a building that may not be burning.
Arsenic in mine tailings is not necessarily dangerous.
In the ground, in the form of arsenopyrite, it is stable and non-threatening. But exposure to the air and oxidation can change things, turning arsenic into arsenate. If ingested, arsenate may pass harmlessly through the body. Or it may migrate to vital organs, where repeated exposure can cause serious harm.
Arsenic that stays in the body is called "bioavailable," but there is no quick and easy way to measure bioavailability. Arsenic may be detected in alarming quantities as it has in Amador County and still not be bioavailable. On the other hand, it may show up in very small amounts and be highly bioavailable.
Consultants retained by the federal Environmental Protection Agency to analyze the Mesa de Oro tailings say it could take six months or longer before the level of arsenic hazard there is known. And because the geology and chemistry of mine tailings differ, the Mesa de Oro analysis may have little application to arsenic elsewhere in the gold country.
In the midst of the uncertainty, critics have accused state and federal officials of behaving irresponsibly.
"They just went off and scared the hell out of people," said Doug Ketron, a mining engineer who lives in Sutter Creek but says he has no financial interests in the region. "They've got people telling their children to hold their breath when they go outside."
One bioavailability study done in the region tends to reinforce Ketron's doubts.
Testing done for the state by Robert Borch at one of the mine sites in Jackson showed that the arsenic there is "essentially unavailable." But Borch characterized the tests as preliminary and emphasized that a lot more work is needed.
"The issue has been divisive," said Sutter Creek City Atty. Brad Sullivan. "Some people feel that the government is making a tempest in a teapot. Others feel that, by gosh, the government is doing its job by alerting people."
Sullivan said he is relieved that state and federal agencies have intervened.
"This is way beyond the capacity of a rural county to deal with," he said, noting that a local analysis of the proposed Mesa de Oro subdivision site in 1985 did not detect high levels of arsenic in the soil.
Elsewhere in the region, local officials are not waiting for definitive soil tests before they take measures to prevent new development adjacent to old mine tailings.
In Nevada County, Health Director Tim Snellings said officials have called a halt to a proposed development almost a quarter of a mile away from tailings where arsenic levels were measured at about 60 times what the state considers safe.
Snellings has been meeting with other officials in the gold country over the mine tailings issue and said the counties faces a real dilemma.
"They want to promote development and at the same time be responsible for the public health," he said. "We're trying to come up with a set of procedures that will identify the places to be avoided or remediated (cleaned up)."
Consultant Borch has estimated that 50,000 abandoned mine sites dot California, with the greatest concentration in the gold country.
"We're simply not going to be able to clean up every one," he said in a recent interview. "Potentially, the price could be in the hundreds of millions."