Bioaccumulation in the context of "Biotransformation"

Micropollutants are substances that even at very low concentrations have adverse effects on different environmental matrices. They are an inhomogeneous group of anthroprogenic chemical compounds that is discharged by human to the environment. Commonly known micropollutants that might pose possible threats to ecological environments are, to name just a few:

• environmental persistent pharmaceutical pollutants and personal care products,
• pesticides,
• stimulants,
• persistent organic pollutants,
• and artificial sweeteners

To date, most of the scientists have identified wastewater treatment plants as the main source of micropollutants to aquatic ecosystems and/or adversely affect the extraction of potable water from raw water. Due to in many places drinking water is also extracted from surface waters, or the substances also reach the groundwater via the water, they are also found in raw water and must be laboriously removed by drinking water treatment. In addition, some of the substances are bioaccumulative, which means that they accumulate in animals or plants and thus also in the human food chain.

Filter feeders are aquatic animals that acquire nutrients by feeding on organic matter, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a specialized filtering organ that sieves out and/or traps solids. Filter feeders can play an important role in condensing biomass and removing excess nutrients (such as nitrogen and phosphate) from the local waterbody, and are therefore considered water-cleaning ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms.

Filter feeders can be sessile, planktonic, nektonic or even neustonic (in the case of the buoy barnacle) depending on the species and the niches they have evolved to occupy. Extant species that rely on such method of feeding encompass numerous phyla, including poriferans (sponges), cnidarians (jellyfish, sea pens and corals), arthropods (krill, mysids and barnacles), molluscs (bivalves, such as clams, scallops and oysters), echinoderms (sea lilies) and chordates (lancelets, sea squirts and salps, as well as many marine vertebrates such as most species of forage fish, American paddlefish, silver and bighead carps, baleen whales, manta ray and three species of sharks—the whale shark, basking shark and megamouth shark). Some water birds such as flamingos and certain duck species, though predominantly terrestrial, are also filter feeders when foraging.

In marine and freshwater ecology, a particle is a small object. Particles can remain in suspension in the ocean or freshwater. However, they eventually settle (rate determined by Stokes' law) and accumulate as sediment. Some can enter the atmosphere through wave action where they can act as cloud condensation nuclei (CCN). Many organisms filter particles out of the water with unique filtration mechanisms (filter feeders). Particles are often associated with high loads of toxins which attach to the surface. As these toxins are passed up the food chain they accumulate in fatty tissue and become increasingly concentrated in predators (see bioaccumulation). Very little is known about the dynamics of particles, especially when they are re-suspended by dredging. They can remain floating in the water and drift over long distances. The decomposition of some particles by bacteria consumes much oxygen and can cause the water to become hypoxic.

Edible mushrooms are the fleshy fruit bodies of numerous species of properly identified and prepared fungi. Edibility may be defined by criteria including their palatability and absence of dangerous mycotoxins. Edible mushrooms are consumed for their nutritional and culinary value, often either being cultivated or harvested wild. Easily cultivated and common wild mushrooms are often available in markets; those that are more difficult to obtain may be collected on a smaller scale.

To ensure safety, wild mushrooms must be correctly identified before their edibility can be assumed. Deadly poisonous mushrooms that are frequently confused with edible mushrooms include several species of the genus Amanita, particularly A. phalloides (the death cap). Some mushrooms that are edible for most people can cause allergic reactions in others; old or improperly stored specimens can cause food poisoning. Additionally, mushrooms can absorb chemicals from polluted locations, accumulating pollutants and potentially lethal heavy metals.

The environmental effect of pharmaceuticals and personal care products (PPCPs) is being investigated since at least the 1990s. PPCPs include substances used by individuals for personal health or cosmetic reasons and the products used by agribusiness to boost growth or health of livestock. More than twenty million tons of PPCPs are produced every year. The European Union has declared pharmaceutical residues with the potential of contamination of water and soil to be "priority substances".

PPCPs have been detected in water bodies throughout the world. More research is needed to evaluate the risks of toxicity, persistence, and bioaccumulation, but the current state of research shows that personal care products impact the environment and other species, such as coral reefs and fish. PPCPs encompass environmental persistent pharmaceutical pollutants (EPPPs) and are one type of persistent organic pollutants. They are not removed in conventional sewage treatment plants but require a fourth treatment stage which not many plants have.