bioakkumuláció

Bioakkumuláció, also known as biological accumulation or biomagnification, is the accumulation of substances, such as pesticides or other chemicals, in the tissues of living organisms. This process occurs when an organism absorbs a substance at a rate faster than that at which it is lost by catabolism and excretion. Bioakkumuláció can occur in any organism, but it is most commonly associated with the accumulation of toxins in food chains.

When organisms are exposed to a substance, they absorb it into their bodies. If the substance is not readily metabolized or excreted, it can build up in the organism's tissues over time. This is particularly true for substances that are fat-soluble, as they tend to be stored in fatty tissues.

As these contaminated organisms are consumed by other organisms higher up the food chain, the concentration of the substance increases at each trophic level. This phenomenon is called biomagnification. For example, if small fish ingest contaminated plankton, they accumulate the substance. Then, larger fish that eat many of these small fish will accumulate even higher concentrations of the substance. This process can continue up the food chain, leading to very high concentrations in top predators, including humans.

Many substances can bioaccumulate, including heavy metals like mercury and lead, as well as persistent organic pollutants (POPs) such as DDT and PCBs. The effects of bioakkumuláció can range from subtle physiological changes to severe health problems, including reproductive issues, developmental disorders, and increased cancer risk. Understanding bioakkumuláció is crucial for assessing the environmental risks associated with chemical pollution and for protecting both ecosystems and human health.