Human health can be affected by acute or chronic exposure to toxicants, through the media of water, wet land sediments, or even air when sediments becom dessicated and airborne or burnt. The nature of thes exposures is exacerbated by human behaviours and activities and they can result whenever ecosystem services have been eroded – especially when the hydrological services that maintain biological, geo logical and chemical processes have been distorted by human activities of over extraction of water. Drainage and diversions of water are the two activi ties responsible for the majority of such changes. Wetlands are often the loci for communicable disease where microorganisms (the.
