Ethics of pesticide testing: response.

We thank Landrigan et al. for raising the important issue of ethics in relation to human studies of pesticide exposure. This issue was considered in great detail before we began our study with fenitrothion. We agree that ethical standards should be developed as soon as possible to protect the safety of volunteers and the broader public health needs of the community.

Landrigan et al. consider the fundamental issue to be that our volunteers were administered a substance that could "... in no conceivable way ... benefit the health of that person." They state that, in this respect, our studies differ from more ethically acceptable studies of pharmacologic agents in humans.

In our view, this comparison is not appropriate because a high proportion of drug-related research, especially in early phase studies, involves volunteers who gain no benefit from their participation.

Our study was subjected to extensive ethical review by an institutional ethics committee. The role of this committee was to make an independent determination about the acceptability of the risks to the study participants and whether the risks were appropriately explained in the documentation provided to them. A secondary issue was whether the study itself could be justified in the context of community benefit. These are considerations applied to all volunteer studies, including those for new drugs.

Before approving this study, the Institutional Ethics Committee of Monash University went further by seeking outside scientific advice and requiring an independent expert clinician be available to counsel volunteers. The participants were mostly individuals with medical or scientific qualifications, and several had a specific knowledge of pesticide toxicology. A. McLean and I (J.J.M.) were the first participants to be studied.

One important issue to consider is whether it is ethical to expose large human populations to pesticide residues without specific knowledge of the way the agents are handled by humans, or reassurance about an adequate safety margin between exposure levels and adverse effects. A reasonable attitude is that studies involving informed and consenting volunteers, who are exposed to controlled low doses of the agents in question and carefully monitored for ill effects, are more ethically acceptable than exposing whole populations without the reassurance provided by this information.

Our study (Meaklim et al. 2003) was undertaken because, at the time, fenitrothion was the principal pesticide residue to which this population was exposed. The study, undertaken in accordance with the highest ethical standards, could contribute to the model Landrigan et al. believe should be established by the U.S. Environmental Protection Agency.

The authors declare they have no conflict of interest.

John J. McNeil

Jean Meaklim

Department Epidemiology and Preventive Medicine 

Monash University

Melbourne, Australia

E-mail: [e-mail]

REFERENCE

Meaklim J, Yang J, Drummer OH, Killalea S, Stakos V, Horomidis S, et al. 2003. Fenitrothion: toxicokinetics and toxicologic evaluation in human volunteers. Environ Health Perspect 111:305-308.