Water is an essential source of life and is one of the most vulnerable environmental compartments. Consequently, water pollution has become a matter of utmost interest and concern worldwide, including in South Africa.
Polluted water, according to the World Health Organisation (WHO), is water of which the composition has been changed to the extent that it is unusable. It is toxic and not fit for human consumption or used for essential purposes like agriculture, and which also causes diseases like diarrhoea, cholera, dysentery, typhoid fever and poliomyelitis.
The main water pollutants include bacteria, viruses, parasites, fertilisers, pesticides, pharmaceutical products, nitrates, phosphates, plastics, faecal waste, and even radioactive substances. In addition, there is also now what is referred to as emerging pollutants.
Broadly speaking, emerging pollutants can be understood as any synthetic or naturally-occurring chemical or any microorganism that is not commonly monitored or regulated in the environment with potentially known or suspected adverse ecological and human health effects.
These contaminants include mainly chemicals found in pharmaceuticals, personal care products, pesticides, industrial and household products, metals, surfactants, industrial additives and solvents. Many of them are used and released continuously into the environment even in very low quantities and some may cause chronic toxicity, endocrine disruption in humans and aquatic wildlife and the development of bacterial pathogen resistance.
Emerging pollutants
Scientific knowledge and understanding on potential human and ecosystem health risks posed by emerging pollutants is still very scarce, as well as on their presence in water resources and wastewater and their pathways and accumulation in the environment. Most emerging pollutants are not regulated in environmental, water quality and wastewater discharge regulations.
Hence, there is an urgent need to strengthen scientific knowledge and adopt appropriate technological and policy approaches to monitor emerging pollutants in water resources and wastewater, assess their potential human health and environmental risks, and prevent and control their disposal to water resources and the environment.
Emerging Freshwater Pollutants: Analysis, Fate and Regulations, a book edited by University of Mpumalanga lecturer of Water Management, Dr Tatenda Dalu and Nikita T. Tavengwa from the University of Venda, examines these emerging water pollutants.
The book provides current analytical approaches and instrumental analyses, fate and occurrence of emerging pollutants in aquatic systems and management policies and legislations on emerging pollutants which covers challenges and the future directions.
Written by leading academic experts, the book contains numerous helpful examples and case studies, and can be used as a practical guide and important educational tool on issues concerning emerging freshwater pollutants.
Emerging pollutants can be be discharged into any of the environmental compartments which include air, soil and sediments. One major concern is when they are discharged into water bodies as most of them end up in aquatic systems. These compounds can even partition between the aqueous phase and the sediments.
Some of them might end up accumulating in the food chain causing various diseases. They have the potential to enter the environment and cause adverse ecological or human health effects. The behaviour of different emerging pollutants after their entry into the environment is very important.
Challenges
There is a scarcity of qualitative and quantitative information regarding the status of emerging pollutants in aquatic bodies within the developing world. Not much literature is available from the developing world on emerging pollutants, with countries such as South Africa and Brazil leading the way in terms of research, leaving the rest of the developing world countries with little or no information on the distribution and fate of these compounds in aquatic environments.
This may be because of the lack of instruments and skilled personnel to carry out this research as these emerging pollutants occur in trace amounts. The available information has been put together comprehensively in this new book which will become a reference point for researchers and environmentalists within the developing world.
The book aims to primarily document what is known on emerging freshwater pollutants from a developing world perspective. It is intended as a practical guide and important educational tool to scientific and management issues concerning emerging freshwater pollutants within the tropical regions.
Data on emerging pollutants is often very scarce, mostly due to analytical and detection methods which may be non-existent or in the early stages of development for them to detect these pollutants in the natural environment. Most emerging pollutants are not regulated, which is why there is an urgent need to strengthen scientific knowledge surrounding this issue.
Solutions
More than 700 emerging pollutants have been categorized into 20 classes only in the European aquatic environment. There exists a gap in the knowledge on their fate, behaviours and effects, as well as on treatment technologies for their efficient removal.
The distribution of pollutants to various environmental compartments is usually through leaching, agricultural run-offs, and air particulates. This distribution results in their presence in surface water, ground water and wastewater treatment plants (WWTPs).
Most of the time, emerging pollutants from various sources end up in WWTPs. The mandate of these WWTPs is to treat (clean) water laden with potential harmful analytes such as emerging pollutants before being discharged back into the environment.
This is very important as it safeguards humans and aquatic animals. However, the efficiencies of WWTPs in developing countries has not been well documented in a single document. For example, WWTPs have been estimated to be one of the point sources of antibiotics within South Africa.
The information on the presence and concentration of emerging pollutants is a very important step towards remedial action (removal techniques). The volume includes 20 chapter contributions from authors based at or attached to several institutions around the world, including South Africa.
@ Additional information is extracted from the book: Emerging Freshwater Pollutants: Analysis, Fate and Regulations (editors: Tatenda Dalu, Nikita T Tavengwa), Elsevier Publishers, Cambridge, MA, USA, which includes original research contributions in international emerging freshwater scholarship, particularly covering the developing world.