Water and health. [Chapter 6 of 'Sustainable water: chemical science priorities summary report']

Water transports contaminants, including inorganic, organic and biological materials, from various sources both natural and man-made. Such contaminants can enter the human body via water by ingestion, inhalation of water droplets and contact, particularly with broken skin.
Water borne diseases have historically had the greatest impact upon human health and continue to contribute to millions of deaths globally per year. Water use and sanitation in the form of hygiene practices act as an important barrier to disease transmission. Disease incidences in countries without basic water and sanitation services are estimated to be eleven times higher for than those in areas with clean water, hygiene practices, and the safe disposal of human wastes.
Naturally occurring arsenic compounds (in particular toxic organic species) contaminate substantial groundwater sources. The most seriously affected areas in Sustainable Water: Chemical Science Priorities Royal Society of Chemistry report the world are in India and Bangladesh. Here, 60–100 million people are currently at risk of poisoning as a result of drinking contaminated groundwater where the arsenic arises from the natural bedrock geology. There is a need for portable field-testing kits that are quick, accurate, cheap and reliable that can support remediation efforts. Additionally there is a need for arsenic mitigation technologies that are effective and appropriate for use by local populations. There is also a growing problem with uranium contamination of groundwater, particularly in Eastern Europe.
Society is reliant upon man-made chemicals, particularly for food and health, and inevitably such chemicals end up in water systems. Typically these chemical contaminants are either neurotoxins, pharmaceutically active or endocrine disruptors. Additionally there is growing concern over multiple chemical sensitivity1, although scientific evidence is insufficient to prove or disprove this theory at this time. There are two specific problems with man-made chemicals in wastewater: firstly, treatment plants are not designed to remove these chemical products; secondly, chemicals entrained in sediments can be mobilised by chemical and biological processes.
Traditionally, pollution by man-made chemicals is reduced by either dilution or through end of pipe remediation technologies. This can be minimised by adopting good practice and integrated pollution prevention and control. This would include measures such as minimising the quantity of materials used and recovering unused materials. Additionally, industrial waste streams should be concentrated as far as possible and mixtures of materials should be avoided, as this will require additional treatment steps and effort.