ens to increase soon) have recently caused some public- 

 health scares. Noroviruses — headlined for causing cruise 

 ship infections — are already on the rise. Cryptosporidium 

 parvum sickened some 400,000 residents of Milwaukee, 

 Wisconsin in 1993, when the local water-treatment pro- 

 cess was changed in what had seemed to be a minor way. 

 E. coli 0157:H7 is another of the more common emerging 

 infectious pathogens in the U.S. joining the hefty ranks 

 of dangerous bacteria, many 

 of which are becoming re- 

 sistant to multiple standard 

 antibiotics. 



But pathogenic micro- 

 organisms are not the 

 sole cause of water- 

 associated illnesses. Chemi- 

 cals, too, pose serious risks. 

 About a thousand new syn- 

 thetic compounds are intro- 

 duced every year, joining 

 the ranks of tens of thou- 

 sands more that are already 

 in widespread use — diox- 

 ins, PCBs, and halogenated 

 hydrocarbons included. 

 Many inevitably seep into 

 the water system and ac- 

 cumulate in the food chain. 

 In the United States, for 

 instance, some 700 chemi- 

 cals have been detected in 

 drinking water sources, 

 and more than a hundred 

 of those chemicals are considered highly toxic. 



Advanced technologies enable investigators to detect 

 harmful chemicals in the water supply, even in low con- 

 centrations — a critical step, since their effects on human 

 health are often unknown. Several emerging chemicals 



of utmost concern are fuel additives, such as methyl 

 tertiary-butyl ether, or MTBE; by-products of disinfec- 

 tion; antibiotics, hormones, and psychoactive drugs; the 

 antibacterial soap ingredients triclocarban and triclosan; 

 and persistent organic pollutants, such as perfiuorinated 

 chemicals and phthalates. 



Most people have a sufficiently robust immune system 

 to handle exposure to a certain amount of water pollut- 

 ants. But some — infants, the elderly, people living with 

 cancer or AIDS — are immunocompromised. Elderly adults 

 often sicken on exposure to only a small fraction of the 

 infectious dose that others require — an issue for the U.S. 

 as it baby boomer population ages. 



J 



Drawing copied from the wall of an Egyptian pharaoh's tomb — 

 dated to about 1450 B.C. — depicts an early method of water 

 purification. One person, shown on right, pours water into the 

 purifier, while another, shown on left, appears to use suction 

 power to draw the water through a series of filters. 



ust as an aging population poses a concern for public 

 health, so too does an aging infrastructure pose a 

 concern for water delivery. U.S. water infrastruc- 

 ture is outdated and deficient. In the next few decades, 

 measures must be taken to reinforce or restore our water 

 delivery pipes and systems, equipping them for both natural 

 disasters and terrorist threats. 



Once again the United 

 Nations has declared a water 

 decade: 2005 through 2015 

 will be the Water for Life 

 Decade. Among the UN's 

 Millennium Development 

 Goals outlined for the decade 

 are reducing the number of 

 people worldwide who lack 

 adequate water and sanitation 

 by half. Additional efforts 

 will concentrate on curbing 

 the unsustainable exploita- 

 tion of water. As with the 

 UN's approach to increasing 

 literacy, facilitating income 

 generation, and curbing 

 population growth, the fo- 

 cus will be on empowering 

 women as a means of achiev- 

 ing its goals. 



Certainly the goals are 

 challenging. Achieving 

 them will require coopera- 

 tion among many stakehold- 

 ers who are committed to 

 expanding investments in water and wastewater infra- 

 structure. New management strategies must embody 

 conservation and efficiency for people everywhere, lest 

 we find ourselves changing too slowly to quench the 

 world's thirst. 



To find Web links related to this article, visit 

 www.naturaihistorymag.com and click "Online Extras," then "Web Links," and finally "November 2007." 



November 2007 NATUR.AI HISTORY 



