25 Jul 2007
EPIDEMIOLOGY EXPERTS FIND SERIOUS ERRORS IN PLAINTIFFS' CANCER STUDIES IN ECUADORIAN AMAZON
Actual Cancer Rates Lower than Claimed by Plaintiffs; Findings Published in International Medical Journal
San Ramon, California, July 25, 2007-The findings of Miguel San Sebastian et al. regarding cancer in San Carlos are flawed, according to an analysis conducted by Drs. Alejandro Arana and Felix Arellano and published in the July issue of Occupational and Environmental Medicine. The journal reported that cancer rates in San Carlos are actually lower than the plaintiffs allege.
The analysis points out that in his original study, Miguel San Sebastian et al. underestimated the population of San Carlos by some 50 percent, which in turn substantially overestimated cancer rates in the region. As a result, San Sebastian's writings do not provide evidence that diseases were caused by petroleum or that the incidence of cancer was greater than would be expected in a similar population.
According to, "Cancer Incidence Near Oilfields in the Amazon Basin of Ecuador Revisited" by Alejandro Arana of Risk Management Resources España, Zaragoza, Spain and Felix Arellano of St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, fewer cases of cancer occurred in the area examined by San Sebastian than would normally be expected for the number of people actually living there.
Drs. Arana and Arellano further point out that the prior work of San Sebastian et al, contained fundamental flaws by:
- Severely underestimating the population of San Carlos (Official Government of Ecuador census data show that the population was substantially larger than estimated by San Sebastian et al) and,
- Assuming that the population did not increase over an 11 year period.
Despite these flaws, the writings of San Sebastian entitled, "Exposures and Cancer Incidence Near Oil Fields in the Amazon Basin of Ecuador" continue to be used by plaintiffs' attorneys to support their unfounded allegations in the ongoing environmental litigation against a former Texaco subsidiary.
Alejandro Arana and Felix Arellano are two of a number of independent epidemiologists and experts on tropical health issues who have effectively refuted the claims of San Sebastian and the plaintiffs' attorneys.
Dr. Ken Satin, Technical Team Leader, Epidemiology for Chevron, said, "Despite the overwhelming body of scientific evidence pointing out the flaws and limitations of the San Sebastian study, plaintiffs continue to reference this information in an attempt to mislead the court and the international community. The plaintiffs' attorneys refuse to acknowledge what many physicians, epidemiologists and health organizations conclude: That the health conditions in the Oriente region are likely the result of the widespread poverty, malnutrition, insufficient access to medical care and a lack of water treatment and sanitation systems."
A copy of the letter published in Occupational and Environmental Medicine can be found at http://www.texaco.com/sitelets/ecuador/docs/2007_oem_article.pdf (PDF, 110 KB).
Full details of the methodology used by Alejandro Arana and Felix Arellano for their analysis, "Cancer Incidence Near Oilfields in the Amazon Basin of Ecuador Revisited" can be obtained from the authors at http://www.riskmr.com.
Additional information on this litigation and the flaws in the medical studies promoted by the plaintiffs' can be found at http://www.texaco.com/sitelets/ecuador/en/.
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