Reports & Consumer Guides
Chrome-Plated Fraud: Chronology
1965 — 1974: Water sampling and health surveys near a chromium processing facility in China's Liao Ning province find massive contamination of groundwater and many residents suffering symptoms of chromium poisoning.
1987: JianDong Zhang and XiLin Li publish a study in the Journal of Chinese Preventive Medicine showing an association with chromium-6 exposure to high rates of cancer in the contaminated area.
December 1987: Pacific Gas & Electric Co. advises California regulators they have detected chromium-6 in a Hinkley monitoring well at more than 10 times the state's standard for total chromium.
May 1993: Residents of Hinkley sue PG&E for releasing wastewater contaminated with chromium-6 into the town's groundwater. The 1987 Zhang study is later admitted as evidence, setting off an effort by PG&E consultants McLaren/Hart-ChemRisk to find the study's author.
April 1995: Zhang signs a contract with McLaren/Hart. He is paid $250 a month to provide "document review and consultation regarding epidemiology, groundwater contamination and health effects of chromium."
December 1995: ChemRisk completes its "clarification" of Zhang's 1987 study, omitting data showing higher levels of cancer in the contaminated villages than in the surrounding province. ChemRisk's paper is submitted under Zhang's name to two peer-reviewed journals.
May 1996: ChemRisk's paper is accepted by the Journal of Occupational and Environmental Medicine (JOEM) and the Archives of Environmental Health.
July 1996: PG&E settles the Hinkley lawsuit by paying 650 residents damages of $333 million.
April 1997: The article is published under Zhang's byline in JOEM. It is subsequently cited by the EPA and Agency for Toxic Substances and Disease Registry as evidence that chromium-6 in drinking water does not cause cancer.
March 2000: The film Erin Brockovich, based on the Hinkley case, is released.
September 2000: A new state law requires testing for chromium-6 in Southern California water supplies and an assessment of its health risks.
October 2000: A lawsuit alleging chromium-6 contamination is filed against PG&E by residents of Kettleman City, Calif., eventually including 1,250 claims.
March 2001: The state asks the University of California to convene an expert panel to address whether chromium-6 in water causes cancer. Panel includes former McLaren/Hart and ChemRisk executive Dennis Paustenbach. When the panel's report is released, it concludes that a chromium-6 drinking water standard is not needed, pointing to the 1987 Zhang study as evidence.
August 2001: OEHHA scientist Jay Beaumont takes another look at the 1997 JOEM article and finds "several notable limitations and oddities." He finds that stomach cancer rates in the contaminated villages were much higher than in the surrounding province. He learns that Zhang is dead, but had been a McLaren/Hart consultant.
October 2001: New state law requires adoption of a chromium-6 drinking water standard by January 1, 2004.
December 2002: Depositions and documents filed in the Kettleman City case against PG&E detail efforts by McLaren/Hart-ChemRisk to reverse findings of Zhang's study.
April 2003: At a special legislative hearing, evidence is presented of conflicts of interest among members of the UC panel, including Paustenbach. OEHHA says it will not use the panel's report in setting its public health goal for chromium-6.
Fall 2005: A new draft PHG for chromium-6 is expected from OEHHA.
January 2006: Case brought by Kettleman City, Calif., residents against PG&E over hexavalent chromium contamination of air and drinking water is scheduled to go to trial.