Resources Clean School Bus Related Articles Peer-Review Challenges NRDC Diesel-Fuel Report as Bogus Science
Peer-Review Challenges NRDC Diesel-Fuel Report as Bogus Science PDF Print E-mail
Friday, 01 June 2001 13:29

NEW YORK -- Calling it unsupported "opinion" and "replete with invalid and unsupported assertions," the American Council on Science and Health (ACSH) fired broadside at the claims by the Natural Resource Defense Council (NRDC) and Coalition for Clean Air (CCA) that diesel exhaust emissions from school buses pose a cancer risk to school children. The ACSH charges are found in a published a report titled School Buses and Diesel Fuel, a peer-review analysis by ACSH, that is highly critical of the science in the NRDC/CCA report, No Breathing in the Aisles.


The NRDC/CCA report was issued earlier this year and was instrumental in the decision by the Los Angeles-based South Coast Air Quality Management District to ban the purchase of school buses powered by clean diesel technology. Public fears generated by the report even found their way into the recent election of the school board of the Los Angeles Unified School District.

ACSH is a consumer education consortium of more than 350 scientists and physicians concerned with issues related to food, nutrition, chemicals, pharmaceuticals, lifestyle, the environment and health. It publishes reports to help the public deal with health risks productively. ACSH's top priority is to help Americans distinguish between real and hypothetical health risks. It was founded in 1978 by a group of scientists who had become concerned that many important public policies related to health and the environment did not have a sound scientific basis. These scientists created the organization to add reason and balance to debates about public health issues and bring common sense views to the public.

The ACSH report is not another study of non-occupational diesel exhaust. Instead, it is a peer-review of the NRDC/CCA report that seeks to evaluate its scientific merit and the basis behind its conclusions. ACSH charges the NRDC/CCA with "failure to follow standard scientific protocols and a lack of attention to methodological details." Twelve emminent scientists participated in the peer review.

  • ACSH concluded the monitoring study, which forms the basis of the report and from which the NRDC/CCA based its risk estimates for children, is not described in sufficient details, nor are enough data presented to allow for a thorough and informed critique of its validity. Thus, the conclusions regarding cancer risk to children from diesel exhaust exposure cannot be confirmed.
  • ACSH concluded the estimated diesel exhaust exposures for children riding a diesel-fueled school bus have not been confirmed through other indpendent studies. It notes that quantitative human exposure data are rarely available, and therefor comparisons to the NRDC/CAA findings are not possible.
  • ACSH concluded that no published studies are known that link ambient or non-occupantional exposure to diesel exhaust with increased cancer risk.
  • ACSH concluded the estimated cancer risk for children calculated by the NRDC/CCA uses a unit risk factor that has not received general acceptance by the scientific community and is not currently used by the U.S. Environmental Protection Agency.
  • ACSH concluded that no case reports or studies are known to link childhood exposure to diesel exhaust, either on buses or in any other exposure scenario, with an increased risk of developing cancer.

In its summary statement, ACSH wrote: "The conclusions presented in the NRDC/CCA report should be viewed a opinions based on limited data and risk estimations, as scientific evidence is currently lacking to support the claim that school bus exposures are associated with an increased risk of cancer to children."

Copies of the report are available from the ACSH for $5.00. Write to the American Council on Science and Health, 1995 Broadway, 2nd floor, New York, NY 10023. Or email your request to:  \n // --> This e-mail address is being protected from spambots. You need JavaScript enabled to view it This e-mail address is being protected from spambots. You need JavaScript enabled to view it . A PDF version of the report may be downloaded from the Council's website at

Source: School Transportation News, June 2001.

Last Updated on Monday, 12 October 2009 11:05