Bioaccumulation is the process by which organisms accumulate toxic substances in their bodies from their environment or through their food over time. This accumulation can occur when the rate of uptake of a substance exceeds the rate of elimination. As a result, contaminants can reach harmful levels within an organism, leading to adverse health effects. Bioaccumulation is often observed with persistent organic pollutants (POPs) and heavy metals, which can accumulate in fatty tissues and magnify through the food chain, affecting higher trophic levels in ecosystems.