Exposure Assessment: Accurately measuring exposure levels can be difficult, especially when dealing with historical exposure or low concentrations of chemicals. Confounding Factors: These are variables that can obscure the true relationship between exposure and health outcomes. Identifying and controlling for these factors is essential for reliable results. Sample Size: Large sample sizes are often needed to detect small effect sizes, making studies resource-intensive. Bias: Selection bias, information bias, and other forms of bias can affect the validity of the study findings.
