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Water, Sanitation and
Environmental Health MeasuresEnvironmental Health Measures
Dr. Homero Silva
Environmental Health Advisor
PAHO/WHO Jamaica
Cholera is the result of the existing
social debt in water and sanitation in
many countriesmany countries
Cholera reflects the existing
inequities in Water and Sanitation in
and within countriesand within countries
Drinking Water Coverage Comparison
Haiti and Dominican Republic
70
80
90
100
0
10
20
30
40
50
60
Urban Rural Total
% Water Coverage
Haiti
Dominican Republic
Sanitation Coverage Comparison
Haiti and Dominican Republic
70
80
90
100
0
10
20
30
40
50
60
Urban Rural Total
% Coverage
Haiti
Dominican Republic
Cholera Cases Frequency by Epi Week Dominican Republic
2010-2011
Total Number of cases Haiti and
Dominican Republic
• Haiti 243,197
• Dominican Republic 572
The Great Caribbean RegionEstados Unidos de América
Cuba
Haiti
Belice
República Dominicana
Jamaica Puerto Rico
Las Bahamas
Islas Caimán
Anguila
Turks & Caicos Is.
30N
20N
25N Golfo de
MéxicoOcéano
Atlantico
Colombia
Venezuela
México
Guyana
Honduras
Surinam
Nicaragua
Guatemala
Panamá
Guyana Francesa
Costa Rica
Belice Jamaica Puerto Rico
Trinidad & Tobago
Guadalupe
MartinicaSta. Lucía
BarbadosGranada
Antigua & Barbuda
Anguila
Dominica
San Kitts & Nevis
San Vincente & Las Granadinas
Montserrat
5N
10N
15N
65
W
95
W
55
W
50
W
70
W
75
W
80
W
85
W
90
W
60
W
0 500 1,000250 Km
Mar Caribe
Océano
Pacifico
Division of the Great Caribbean Region in 5
sub-regions
The Risks
• Outside Threats
– People and Goods movement
– Sea Currents
– Ballast Water
• Inside Threats• Inside Threats
– Water
– Excreta
– Food
– Hygiene Conditions
Common Sources of Infection
• Drinking−water that has been contaminated at its source or during storage, and ice made from contaminated water.
• Food contaminated during or after preparation. e.g. milk, cooked rice, lentils, potatoes, beans, eggs, and chicken.
• Seafood. Particularly shellfish, taken from contaminated water and eaten raw or insufficiently cooked.
• Fruit and vegetables grown at or near ground level and fertilized with night−soil, irrigated with water containing human waste, or "freshened" with contaminated water, and then eaten raw.
Drinking Water Coverage
70
80
90
100
0
10
20
30
40
50
60
Ha
iti
Dom
inic
an
Rep
ub
lic
Suri
na
me
Gu
yan
a
Ja
maic
a
Tri
nid
ad a
nd
To
ba
go
Ca
ym
an
Belize
Sa
int K
itts
an
d
Ne
vis
Mon
serr
at
Ba
rba
do
s
Tu
rks a
nd
Ca
ico
s
% Coverage
Water Treatment and Disinfection
• Chlorine Disinfection is very effective for
Vibrio Cholera;
Factors affecting Disinfection
– Turbidity
– Nitrogen Content– Nitrogen Content
– Organic Matter (BOD5)
Figure No 4 .What are the Trihalomethanes (THM)?
• Trihalomethanes (THM) are a group of four chemicals that are formed along with other disinfection by products when chlorine or other disinfectants used to control microbial contaminants in drinking water react with naturally occurring organic and inorganic matter in water.
• The trihalomethanes are chloroform, bromodichloromethane, dibromochloromethane, and bromoform.
• They are Cancer Group B carcinogens (shown to cause cancer in laboratory animals). Trichloromethane (chloroform) is by far themost common in most water systems. Dibromochloromethane is the laboratory animals). Trichloromethane (chloroform) is by far themost common in most water systems. Dibromochloromethane is the most serious cancer risk, (0.6 ug/l to cause a 10-6 cancer risk increase) followed in order by Bromoform (4 ug/l), and Chloroform (6 ug/l).
• WHO Drinking water guidelines, third edition recommends the following maximum allowable concentration:– Chloroform 0.2 mg/litre,
– Bromoform 0.1 mg/litre,
– Dibromochloromethane 0.1 mg/litre (DBCM) and
– Bromodichloromethane 0.06 mg/litre (BDCM)
Supplies and Equipment for
Drinking WaterDrinking Water
Digital Residual Chlorine
Rapid Tests for Total Coliforms with
no incubation
System SURE Plus measures
Adenosine triphosphate (ATP).
The universal energy molecule
found in all animal, plant,
bacterial, yeast and mold cells.
Residues, particularly food or
organic residue, contain large
amounts of ATP.
COD Tester
Straw Filters
• The LifeStraw is a plastic tube 31 centimeters long and 30 millimeters in diameter, and costs around $ 5.50 plus shipping
• Water that is drawn up through the straw first passes through hollow fibers that filter water particles down to 15 through hollow fibers that filter water particles down to 15 microns across, using only physical filtration methods and no chemicals.
• The entire process is powered by suction, similar to using a conventional drinking straw, and filters up to 1000 liters of water.
• While the initial model of the filter did not remove Giardia Liamblia, later models (starting—date/reference needed--) do remove a minimum of 99.9% of waterborne protozoan parasites including giardia and cryptosporidium
Filters 18,000 liters ofwater.About 2 years, family Of five, 5 l/day
Double Container Filters
Double Container Filters
Sanitation
Sanitation Coverage in some
Caribbean Countries
60
70
80
90
100
0
10
20
30
40
50
60
Ha
iti
Gu
ya
na
Do
min
ica
n
Re
pu
blic
Ja
ma
ica
Su
rin
am
e
Be
lize
Tri
nid
ad
an
d
To
ba
go
Ca
ym
an
Sa
int K
itts
an
d
Ne
vis
Mo
nse
rra
t
Gre
na
da
An
gu
illa
Ba
rba
do
s
Ba
ha
ma
s
Excreta Disposal
On-site
Sewerage
Wastewater Treatment Plants
Excreta Disposal
• Latrines
• Septic Tanks
• Sewerage Systems• Sewerage Systems
– Sewage Treatment Plants
– Ocean outfalls
Excreta Disposal in CTUs
Pollution by In-situ Treatment
Removal of Vibrio Cholera
• Septic Tanks Poor
• Stabilization Ponds Good
• Activated Sludge, • Activated Sludge,
oxidation ditch,
pacakage Plants, etc. Poor
• Ocean Outfalls Poor
• Disinfection is required
Factors affecting Disinfection
– Turbidity
– Nitrogen Content– Nitrogen Content
– Organic Matter (BOD5)
Ocean Outfall
The Great Caribbean RegionEstados Unidos de América
Cuba
Haiti
Belice
República Dominicana
Jamaica Puerto Rico
Las Bahamas
Islas Caimán
Anguila
Turks & Caicos Is.
30N
20N
25N Golfo de
MéxicoOcéano
Atlantico
Colombia
Venezuela
México
Guyana
Honduras
Surinam
Nicaragua
Guatemala
Panamá
Guyana Francesa
Costa Rica
Belice Jamaica Puerto Rico
Trinidad & Tobago
Guadalupe
MartinicaSta. Lucía
BarbadosGranada
Antigua & Barbuda
Anguila
Dominica
San Kitts & Nevis
San Vincente & Las Granadinas
Montserrat
5N
10N
15N
65
W
95
W
55
W
50
W
70
W
75
W
80
W
85
W
90
W
60
W
0 500 1,000250 Km
Mar Caribe
Océano
Pacifico
Division of the Great Caribbean Region in 5
sub-regions
Pollution Loads by SubregionSource: UNEP 2009
Sanitation in Great Caribbean Region
• 5.6 million persona (8%) no sanitation
• 42 million (60%) raw wastewater
discharged into the seadischarged into the sea
Sea Currents
Marine Traffic
VIBRIO CHOLERAE
EXCRETION
ASYMPTOMATIC PATIENTASYMPTOMATIC PATIENT 100 100 -- 100,000/g100,000/gASYMPTOMATIC PATIENTASYMPTOMATIC PATIENT 100 100 -- 100,000/g100,000/g
DELICATE STATE PATIENTDELICATE STATE PATIENT 101066 -- 101099/ml/ml
FAECES VOLUME FAECES VOLUME 12 12 -- 20 L20 L
INFECTIVE DOSEINFECTIVE DOSE
ENDEMIC ZONES 104 - 106 (51-75%)
AVERAGE 1000 (25%)
WEAK PERSONS 100Fuente: Dizon y otros, 1967
Greig, 1914Smith, Freter y Sweeney, 1961
The Environmental State
Favourable Conditions for Vibrio
Development and Survival
Temperature (oC)
Growing 16 – 42Growing
Optimum
16 – 42
37
pH 6.4 to 9.6
Nutrients Carbon Organic
Compounds (BOD)
Resistance to Sodium Chloride Concentration < 4%
Sea Surface Temperatures
Surface Salinity
Chlorophyll Concentration
Aragonite Saturation State
Coral Calcification Rates
Survival Time Cholera
Survival times of excreted pathogens in the environment at 20-30°Ca
Water <30 but usually <10 days
Sea Water/Estuaries Years
Sewage <30 but usually <10 days
Soil <20 but usually <10 daysSoil <20 but usually <10 days
Crops <5 but usually <2 days
Milk (Refrigerator)b 2 to 4 weeks
Meat (Refrigerator)b 1 week
Fish and aquatic products(Refrigerator)b 1 to 3 weeks
Fresh Vegetables(Room Temperature)b 1 to 5 days
Glass, porcelain, plastic and metal (Room Temperature)b Less than 4 days
Cutting board and clothb Long time
a WHO (1 989) as summarized from Feachem et al. (1983).
b Symptoms of vibrio cholerae, http://www.health-writings.com/symptoms-vibrio-cholerae/
New Theory Cholerae in Peru
• It has emerged recently
• May be able to answer the long standing question
of how the disease occurred in several places at
the same time along the Pacific northern region of the same time along the Pacific northern region of
Peru.
• This new indicates a strong possibility, and one
that would fit the known observations, is the
association of Vibrio cholerae and marine
plankton
Marine Currents
Cholera in Fresh Water
• In regard to cholera in fresh water environments, V. cholerae has been found to concentrate on the surface of the water hyacinth, and of the water hyacinth, and Lemna minor, a common duckweed found in freshwater environments.
• Temperature and Nutrients have been found are the major factors governing the distribution of cholerae
Ecology of Cholera Survival and
Development
• Pathogenic vibrios are known to be associated
with zooplankton such as copepods with chitin
exoskeletons and with shellfish, including crabs,
shrimp, and crayfish.shrimp, and crayfish.
• Vibrio cholerae is part of the natural flora of the
gut of these animals and has a powerful chitinase
that enhances its growth on the surfaces of
plankton and shellfish.
Sea Currents
Ecology of Cholera Survival and
Development
• Vibrio cholerae will survive in seawater for months or years
• The bacterium can be transported by ocean currents over very long distances. currents over very long distances.
• Work done with phytoplankton, including blue-green algae, suggests that pathogenic vibrios may survive on both zooplankton and phytoplankton in the aquatic environment, but zooplankton act as amplifiers, increasing the numbers to those sufficient to trigger an epidemic.
Ecology of Cholera
Jamaica Coastal Deterioration
• Coastal waters have been progressively deteriorating for a number of years.
• Eutrophication has become a general phenomenon in the past decade. in the past decade.
• Eutrophication has been so serious that many reefs which formerly had more than 95% live coral cover are now more than 95% algae covered.
• Overgrowth of reef corals and "good" sand-producing algae by "bad" fleshy algae took place at different times in different places.
Progress of Coral Reef Affectation
Area Year
Kingston 1950 and 1960
Montego Bay and Ocho Rios 1970Montego Bay and Ocho Rios 1970
Rio Bueno to Runaway Bay 1980
Negril and parts of Western Jamaica 1990
–
THE TOURISM FACTOR
Tour Operators use disease info in
selecting tourist destinations
CARIBBEAN TOURISM�$US21.5Bn industry
�23 million stay-over arrivals
�18 million cruise ship arrivals
�252,300 hotel rooms; 2,200 hotels�252,300 hotel rooms; 2,200 hotels
�Contribution to Caribbean GDP = 15%
�Contribution to Caribbean employment = 15.5%
�Majority of hard currency earnings
Recommendations
• Strengthen Surveillance– Water, wastewater discharges, hospitals WWTP, Raw agricultural products, fish
industry, patients, etc.
• Improve O&M Sewage Treatment Plants– Training operators
– Re conditioning– Re conditioning
• Disinfection of water– Home treatment
• Safe excreta Disposal– Emergency latrines
– Construction of new in-situ technologies (latrines, septic tanks
• Massive Public Education
• Ensure food safety– Cooked food
– Less raw food
– Shelfish
– Food street vending
Thanks