Pollutants, residues and other contaminants in foods obtained from marine and fresh water

Food has been harvested from the seas and rivers for many thousands of years, and provides a valuable source of nutrition. Perhaps one of the biggest changes seen relatively recently over the past few decades is large increase in aquaculture. Farming fish helps to address in part issues around overfishing. Pollution from agriculture, industrial activity and domestic sources can all end up having an impact on rivers and ultimately the Oceans from where it can be distributed globally. Water is critical not only for foods harvested from rivers and seas, but is critical for all farming and food producing activity. In addition to consumption of conventional products such as fish and shellfish, products such as algae are gaining popularity in the West, while they have been consumed in Asia as a traditional and nutritious food for generations. Chemical contaminants include residues of agricultural products such as veterinary medicines and pesticides, persistent organic pollutants such as dioxins, polychlorinated biphenyls, polyfluorinated alkylated substances, brominated flame retardants, heavy metals and arsenic. More visible signs of pollution have been attracting media attention in recent years in terms of plastic waste, and the micro- and nanoplastic fragments associated with this type of pollution is subject of much on-going research. Risks associated with these contaminants need to be assessed but should be balanced against the benefits associated with the vitamins, nutrients, and other beneficial components of seafood. In addition to risks to humans associated with foods harvested from aquatic environments, it is important to consider the risks to the environment associated with pollution sources to ensure a sustainable future.