Transcript The built environment and water

The built environment and water
• Between 1831 and 1854 tens of
thousands of people in England
died of cholera.
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• An 1854 cholera epidemic in
Soho (London) killed 500
people within 250 yards of the
spot where Cambridge Street
joins Broad Street, the location
of this water pump.
John Snow (1813-1858)
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• Determined that cholera
was a water transmitted
disease
• First used a “GIS” to track
an infectious disease
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Vibrio cholerae -- the cholera bacterium
Source: http://www.ph.ucla.edu/epi/snow.html
Snow’s observations:
Forever changed how cities
obtain drinking water
MWRA Distribution System
• Seasonal flooding, waterborne
pathogens caused widespread
disease and death.
• Bangladeshi government, Unicef and
other aid groups, began tube well
installations in 1970’s. Currently,
• 10 million tube wells installed
• 130 million people (97% of
population) obtain drinking water
from groundwater wells
• Early 1990’s - High levels of Arsenic
(As) found in groundwater.
MYANMAR
Bangladesh
• Other regions - e.g. West Bengal,
Taiwan, Vietnam, US (e.g. New
Hampshire), Chile...
Groundwater tube well use and irrigation
Irrigation greatly increased food supply and helped fuel a tripling
of the Bangladeshi population during the last 40 years
Harvey et al, 2005
What is causing the mass poisoning of drinking water in
West Bengal and Bangladesh?
• 50% of wells (46 million people) have As > 10 ug/L
• 28% of wells (28 million people) have As > 50 ug/L
Yu et al., 2002
[As] in groundwater
Lessons learned: Water pollution
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Cities have long experienced water
pollution
Environmental health effects: acute
to chronic illnesses
Access to clean drinking water still
a major issue for a large percentage
of the Earth’s population
Massive water distribution systems
are expensive and are not
necessarily the solution for every
situation
Lake Waban has a complex history
Boston and Worcester RR: 1834 – present
Pb, Cu, Zn, As
Algaecide applications: 1950s – 1980s
Wellesley Apple Orchards: 1850s – 1950s
NaAsO2, As2O3, CuSO4
Pesticides: PbHAsO4, CaHAsO4, Pb5OH(AsO4)3
1850
1900
Henry Woods Sons & Co.:
1848 – 1928
1950
2000
Leaded gasoline: peak usage 1970s
Paint pigments:PbCrO4, BaSO4, Fe4[Fe(CN)6]3
Pb, V, S
Methods
Outlet:
Lower Waban Brook
Inlet:
Upper Waban Brook
Ekman Dredge
2004 Freeze Cores
2006 Freeze Cores
Russian Cores
Sediment samples were analyzed using XRF, ICP-MS, and SEM-EDS.
Distribution of Pb in surface sediments
LEGEND
[Pb] (µg/g)
500 – 1500 µg/g
10000 – 15000 µg/g
15000 – 20000 µg/g
Significantly elevated [Pb] are observed in surface sediments.