Challenges in assessing long-term health effects studies

After almost 50 yr since modern synthetic pesticides first received wide-spread use in the USA, many of the challenges that need to be met in determining their-long term effects on human health remain unanswered. Answers to many of the key challenges, such as accurate exposure assessment, pesticides' role in multifactorial causation of disease, latency, publishing of negative results, misclassification, low-level dose measurement, accurate diagnosis, the role of biomarkers, adequate study design, and adequate funding, will continue to be key factors in investigating the role, if any, of these chemicals in the transmission of human diseases.