Update on Silicon Valley: Health threats

MIT's respected journal Technology Review doesn't sound alarms about industrial practices easily, but when it does, the criticized industry better take heed. A target of an article in the May/June issue is the modern semiconductor industry, which is most prominently linked with Silicon Valley in California, but is rapidly becoming a major multinational presence. The article, "The Not-So-Clean Business of Making Chips," goes a long way in dispelling myths of pristine, well-ventilated workplaces, and highlights the fastgrowing industry's complacency over the safety of its operations.

According to the author, Dr. Joseph LaDou of the University of California-San Francisco School of Medicine the semiconductor industry, which uses large quantities of toxic metals, chemicals, and gases, may be creating significantly greater health and safety problems for its workers than heretofore realized." Of particular concern are the effects of these materials on the reproductive health of the industry's largely female workforce, many of whom are of childbearing age. "The use of highly toxic and flammable materials also poses a serious threat to the safety of residents in surrounding communities," the article points out. "For instance, the rupture of one cylinder containing a toxic gas such as arsine could cause widespread acute exposures among local residents. Recent findings also show that the industry is contaminating the groundwater of nearby communities and polluting the air with photochemical smog." LaDou warns of other dangers as well, including explosions, fires, and electrocution. He carefully spells out the following findings:

• California Department of Industrial Relations' surveys show high relative rates of semiconductor worker illnesses compared to other manufacturing industries and the use of strikingly large quantities of toxic materials, including the deadly arsine, phosphine and diborane gases. LaDou and reporter Alison Bass take apart the semiconductor industry's statistical rebuttals, including its redefinition of "illness" so that "one-time" chemical exposures are instead re-classified as "injuries."

• Because of alleged trade secret restrictions and just plain indifference, manufacturers of these chemicals and gases do not provide adequate information that would be helpful to both semiconductor companies and health professionals in case of accidents or human exposures.

• New semiconductor chip manufacturing processes, such as the replacement of "wet etching" by a process called "dry plasma etching," are introducing new perils that are more difficult to evaluate. In addition, an expanded use of advanced techniques for doping silicon wafers with arsenic, phosphorus, or boron is associated with an increasing number of health complaints by workers.

• Even if the exact toxicity of these gases and chemicals is unknown, exposure to them must not be assumed to be safe. Scientists from the National Institute for Occupational Safety and Health found workers who repeatedly inhaled arsine gas at less than one-tenth the federal standard still excreted arsenic at possible cancer-causing levels. And chronic arsine exposure "may occur without visible signs of red-cell destruction or kidney damage," according to Dr. LaDou.

• Silicon Valley is a serious source of underground leaks of toxic materials from storage, waste and fuel tanks and piping systems. These seepages are contaminating underground drinking water sources.

• While there are no belching smokestacks, semiconductor companies are emitting tons of "reactive organic gases" every day, which are invisible contributors to the formation of photochemical smog.

• As the Environmental Protection Agency languishes over environmental problems of this industry, an "even larger danger" looms: Surrounding communities' emergency facilities are not able to handle the "major disaster" that could result from the rupture of a metal cylinder of arsine gas.

A good physician should prescribe as well as diagnose, according to Dr. LaDou. He recommends more engineering safety prevention through safer materials substitution, the up-to-date training of police, fire and medical personnel to deal with these hazards, and comprehensive follow-up studies of workers' and communities' health and safety.